investigation, study and research performed by us under the supervision of Ashraful Arefin, Sr. Lecturer ... times higher data rate compared to today's mobile broadband networks, ... We tried to assume a better understanding on the ...... AT&T's 4G LTE network was the fastest, followed by T-Mobile LTE, Verizon LTE, T-Mobile.
FEASIBILITY OF MIGRATION FROM 3G TO 4G INCLUDING COMPARATIVE STUDY Submitted By
Md. Kamrujjaman ID: ECE-090100126
Md. Nasibul Alam ID: ECE-090200137
Supervised by
Ashraful Arefin Sr. Lecturer Department of Electrical & Electronic Engineering Northern University Bangladesh
April 2014 DEPARTMENT OF ELECTRONICS & COMMUNICATION ENGINEERING
NORTHERN UNIVERSITY BANGLADESH
APPROVALS The project report titled “Feasibility of Migration from 3G to 4G including Comparative Study”, submitted by Md. Kamrujjaman (ID: ECE-090100126) & MD. Nasibul Alam (ID: ECE-090200137) to the Department of Electronics & Communication Engineering, Northern University Bangladesh, has been accepted as satisfactory in partial fulfillment for the degree of Bachelor of Science in Electronics & Communication Engineering.
__________________________________________________ Ashraful Arefin (Supervisor) Sr. Lecturer, Department of Electrical & Electronic Engineering Northern University Bangladesh
______________________________________________________ Lecturer Department of Electrical & Electronic Engineering Northern University Bangladesh
______________________________________________________ Lecturer Department of Electrical & Electronic Engineering Northern University Bangladesh
___________________________________________________________
Prof. Dr. Md. Shah Alam Head, Department of Electronics & Communication Engineering Northern University Bangladesh
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DECLARATION
We, hereby, declare that the entire thesis work, presented in this report is the outcome of investigation, study and research performed by us under the supervision of Ashraful Arefin, Sr. Lecturer, Department of Electrical & Electronic Engineering, Northern University Bangladesh. We also announce that no part of this report has been or is submitted elsewhere for the award of any degree or diploma.
Signature
__________________ Md. Kamrujjaman ID: ECE-090100126
__________________ Md. Nasibul Alam ID: ECE- 090200137 Countersigned
__________________________________ Ashraful Arefin Sr. Lecturer (Supervisor) Dept. of Electrical & Electronic & Engineering Northern University Bangladesh
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ABSTRACT 3G and 4G are the modern wireless telecommunication technology. In 3G, network is required to meet a set of technical standards for speed and reliability, and must offer peak data transfer rates of at least 200 kilobits per second in other hand 4G, network must offer peak data rates of at least 100 megabits per second for high mobility communication (users in cars, trains, etc.) and at least 1 Gigabit per second for low mobility communication. Smooth 3G to 4G migration without a “forklift” upgrade – in a single common core platform. The new 4G network will do for broadband what mobile telephony did for voice. With real-time performance, and about 10 times higher data rate compared to today's mobile broadband networks, consumers can always be connected, even on the move. In this condition though 4G have some limitation but we propose to migrate 3G to 4G technology. We tried to assume a better understanding on the „Feasibility of Migration from 3G to 4G including Comparative Study’ for future mobile technology improvement.
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ACKNOWLEDGEMENT First start with great thank to almighty, we take this opportunity to express our profound gratitude and deep regards to our guide Ashraful Arefin for his exemplary guidance, monitoring and constant encouragement throughout the course of this thesis. We can't say thank you enough for his tremendous support and help. We feel motivated and encouraged every time we attend his meeting. Without his encouragement and guidance this thesis would not have materialized.
We sincerely thank the respected teachers and the faculty members of Northern University Bangladesh as they have tremendous contribution behind our progress.
Last but not least we wish to avail ourselves of this opportunity, express a sense of gratitude and love to our friends and our beloved parents for their manual support, strength, and help and for everything.
Authors April 2014
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TABLE OF CONTENTS Approvals……………………………………………………………………………………….. i Declaration……………………………………………………………………………………… ii Abstract …………………………………………………………………………………………iii Acknowledgement ……………………………………………………………………………... iv Table of Contents ………………………………………………………………………………. v List of Figure…………………………………………………………………………………….ix
Chapter
Page No.
CHAPTER ONE Introduction…………………………………………………………………..………… 1 1.1 Mobility Technologies and Standards………...…………………..……..…….......…1 1.2 Zero Generation (0G-0.5G)…………………………………………………………...1 1.3 First Generation Mobile Communication System……..………………...…………....2 1.4 Second Generation Mobile Communication System………………………………....2
CHAPTER TWO The Third Generation Mobile Communication Technology (3G)…..…...………..….3 2.1 Background………………………………………………..……………………...…...3 2.2 Definition of …………………………………………………..…………….……..….3 2.3 Basic Features of 3G Technology……………………………...……….……………..4 2.4 The Four Standards of 3G…………………………...……..………………………….4 2.5 Here are Brief Introductions of Four Kinds of 3G Standards………………................5 2.6 Model Structure of 3G Telemedicine Network………………………...……………..7
CHAPTER THREE The Fourth Generation Mobile Data Protocol (4G)………………………….…...….10 3.1 Long Term Evolution…………………………………………………..………….…11 v
3.2 Understanding WiMAX Technology Standards…………………..………..………..13 3.3 System Architecture…………………………………………….…………………...14 3.4 Physical Layer General Description……………..…………………..........................16 3.5 Uplink Physical Channel……………………………………………..………………17 3.6 Basic Principle Of Ofdma…………………………………………...……………….17 3.7 LTE-Downlink Channel………………………………………...……………………18 3.8 LTE-Uplink Channel………………………...………..…………………..…………19
CHAPTER FOUR 3G and 4G Explained…………………………………………...…………..………….21 4.1 3G and 4G Explained……………………………………………………………..….21 4.2 When to Go For 4G…………………………………………………………..………22 4.3 Should You Even Consider 3G?..................................................................................23 4.4 The Difference……………………………………………………………………….23 4.5 When to go with 3G…………………………………………………………...……..24 4.6 When to go with 4G………………………………………………………………….25 4.7 Understanding 4G Technology Standards……………………………………...……25 4.8 The 4G Confusion…………………………………………………………...……….26 4.9 Understanding LTE Technology Standards………………………………………….27 4.10 Evolution of Different Technical Standards………………………...…………..….27
CHAPTER FIVE Comparison of 3G Wireless Networks and 4G Wireless Networks…………………29 5.1 Introduction………………………………………………………………………….29 5.2 Background Difference………………………………………………………………29 5.3 Network………………………………………………………………………………32 5.4 Bandwidth……………………………………………………………………………34 5.5 Design Specification…………………………………………………………………34
CHAPTER SIX Migration to 4G N………………………………………………………………………37 vi
6.1 Migration to 4G Networks………………………………………………………...…37 6.2 Evolving the Packet Core……………………………………………………...38 6.3 Upgrade Paths to Wireless Broadband ……………………………………...39 6.4 Standard Interfaces and Protocols……………………………………………41 6.5 Converged Mobility and Policy Management………………………...…...42 6.6 Common Core Platform………………………………………………….…..42 6.7 Integrating EPC Network Functions……………………………………..…..42 6.8 Convergence of 3G and 4G Core Networks………………………………….43 6.9 Easing The Migration …………………………………………………..……..44 6.10 Integration of Multiple Core Functions………………………………….…44 6.11 Intelligence in the Network……………………………………………...…45 6.12 EPC Network Functions……………………………………………………... 45
CHAPTER SEVEN 4G Wireless Networks: Opportunities and Challenges…………………………..…..47 7.1 Introduction………………………………………………………………………… 47 7.2 Background……………………………………………………………………...….. 47 7.3 Oppertunities…………………………………………………………………....……49 7.4 New Challenges……………………………………………………..………..…….. 51 7.5 Complex Architecture ………………………………………………………………52
CHAPTER EIGHT Conclusion………………………………………...…………………………….………55
References……………………………………………………………………………………….56
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LIST OF FIGURES 1. Figure 2.1 Topological diagram of 3G telemedicine network…………………………………8 2. Figure 2.2The medical Imaging transmission system in 3G telemedicine…………...………...9 3. Figure 3.1 Architecture of LTE……………………………………………………………….15 4. Figure 3.2 OFDMA system block diagram……………………………………………………18 5. Figure 4.1 Evolution of different technical standards………………..……………………….28 6. Figure 5.1 Architecture……………………………………..…………………………………30 7. Figure 5.2 Architecture……………..…………………………………………………………31 8. Figure6.1 Upgrade Paths to Wireless Broadband………………………..…………39 9. Figure 7.1: 4G will allow everyone to access the Internet from everywhere using almost any wireless device. …………………………………………………………………………………50 10. Figure 7.2: Accessing multiple networks and services through multi-mode software…..….53
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CHAPTER ONE
Introduction
1.1 Mobility Technologies and Standards Mobility solutions require the use of wireless technologies, which enables users to roam freely, while still being in touch with the necessary back-end office infrastructure. Generally speaking, wireless is an old-fashioned term for a radio transceiver (a mixed receiver and transmitter device), referring to its use in wireless telegraphy early on, or for a radio receiver. Now the term is used to describe modern wireless connections such as those in cellular networks and wireless broadband internet, mainly using radio waves. The wireless technologies used in mobility solutions can generally be classified according to their generation, which largely specifies the type of services and the data transfer speeds of each class of technologies.
1.2 Zero Generation (0G – 0.5G) Mobile radio telephone systems preceded modern cellular mobile telephony technology. Since they were the predecessors of the first generation of cellular telephones, these systems are sometimes referred to as 0G (zero generation) systems. Technologies used in 0G systems included PTT (Push to Talk), MTS (Mobile Telephone System), IMTS (Improved Mobile Telephone Service), AMTS (Advanced Mobile Telephone System), OLT (Norwegian for Offending Land mobile Telephony, Public Land Mobile Telephony) and MTD (Swedish abbreviation for Mobile phone system D, or Mobile telephony system D). These early mobile telephone systems can be distinguished from earlier closed radiotelephone systems in that they were available as a commercial service that was part of the public switched telephone network, with their own telephone numbers, rather than part of a closed network such as a police radio or taxi dispatch system. These mobile telephones were usually mounted in cars 1
or trucks, though briefcase models were also made. Typically, the transceiver (transmitterreceiver) was mounted in the vehicle trunk and attached to the "head" (dial, display, and handset) mounted near the driver seat. They were sold through various outlets, including two-way radio dealers. The primary users were loggers, construction foremen, realtors, and celebrities, for basic voice communication.
1.3 First Generation Mobile Communication System The First generation of wireless telecommunication technology is known as 1G was introduced in 1980.The first generation of mobile communication system belongs to the analog communication system, which can only provide low quality voice transmission services. Narrow band analogue wireless network is used, with this we can have the voice calls and can send text messages.
Services are provided with circuit switching.
The speed rate is generally around 14.4 Kbps.
The Systems are: NTT, AMPS, and NMT.
1.4 Second Generation Mobile Communication System The second generation mobile communication system is using digital modulation techniques, based on the first generation to join the technology to support low-speed data services.2G (1990 to 2000) capabilities are achieved by allowing multiple users on a single channel via multiplexing. During 2G Cellular phones are used for data also along with voice. In 2.5G (20012004) the internet becomes popular and data becomes more relevant.2.5G Multimedia services and streaming starts to show growth. Phones start supporting web browsing through limited and very few phones have that. The speed rate is generally:
o 2G: 9.6/14.4 Kbps o 2.5G: 171.2 Kbps (peak) The Systems are: o 2G-TDMA, CDMA o 2.5G-GPRS 2
CHAPTER TWO
The Third Generation Mobile Communication Technology (3G)
2.1 Background The first generation of mobile communication system belongs to the analog communication system, which can only provide low quality voice transmission services. The second generation mobile communication system is using digital modulation techniques, based on the first generation to join the technology to support low-speed data services. In first generation period, because both the numbers of mobile users and business needs were increasing, technology manufacturers stacked a packet-based wireless interface in the GSM communication network which could reach the rate of 115 Kbit / s to achieve fast access to data networks using the GSM technology. However, it was an ideal situation in digital rate. In practice, since many specific restrictions of external factors, the rate is generally around 20 Kbit / s, much slower than in the theory.
2.2 Definition of 3G "3G" is the short for the third generation mobile communication technology. It is a kind of cellular mobile communication technology which can support high-speed data transmission. 3G services can simultaneously transmit voice (call) and data information (e-mail, instant messaging, etc.). The speed is more than a few hundred Kbps generally. The representative feature of 3G is to provide high-speed data services. Relative to the first generation analogue phones (1G) and the second generation GSM, CDMA and other digital phones (2G), generally, the third generation mobile (3G), refers to a new generation of mobile communication systems which combines wireless and multimedia communications with 3
the Internet. It can handle images, music, video and other media streaming including web browsing, conference calls, e-commerce and other information services. In order to provide this service, wireless network must be able to support at least 2 MBps (MB / sec) data transfer speed in the indoor, outdoor and vehicular environments respectively.
2.3 Basic Features of 3G Technology An analysis of the current 3G indicates that, the network feature is mainly in the wireless interface technology. Cellular mobile communication system wireless technology includes cell multiplexing, multiple access / duplex mode, the application frequency, modulation, radio channel parameters, channel coding and error correction, frame structure, the physical channel structure, multiplexing mode and other aspects. Throughout its evolution, 3G wireless technology does not completely abandon the 2G, but fully draws on the operator experience and mature application technology of 2G networks. On the other hand, under the IMT-2000 goals, 3G wireless technology would have the ability of high spectral efficiency, high quality of service to meet the multi-service environment. And it should have good network flexibility and ability of full-coverage. Innovations of 3G wireless technology are mainly in the following areas:
Use of broadband radio frequency channel to support high-speed services
Achieving multi-service and multi-rate transmission
Use of high frequency spectrum
Fast power control
Use of adaptive antennas and software radio technology
2.4 The Four Standards of 3G The International Telecommunication Union (ITU) in May 2000 established W-CDMA, CDMA2000 and TD-SCDMA as the three mainstream air interface standards, which were written into the 3G technical guidance document "2000 International Mobile Communications 4
Plan." On October 19, 2007, the International Telecommunication Union in Geneva held the wireless communications plenary session, after votes from most countries, WiMAX was approved as an official standard of 3G in the world following the WCDMA, CDMA2000 and TD-SCDMA. CDMA is the abbreviation of Code Division Multiple Access, which is the basis of the third generation mobile communication systems technology. The first generation mobile communication system uses frequency division multiple access (FDMA) analog modulation. The main disadvantage of this system is that the spectrum utilization is low and signaling is interfering with voice services. The second generation mobile communication system mainly uses time division multiple access (TDMA) digital modulation methods to enhance the system capacity, and uses independent channels to send signals. It had improved the system performance greatly, but it is still limited for capacity of TDMA systems and handoff performance is still not perfect. The CDMA system has the advantages of simple frequency planning, large system capacity, and high factors of frequency reuse, good anti-multipath capability, and good communication quality. Its own soft capacity and soft switching characteristics show great potential for development.
2.5 Here are Brief Introductions of Four Kinds of 3G Standards: 2.5.1 WCDMA The full name of WCDMA is Wideband Code Division Multiple Access, also known as CDMA Direct Spread. It can support data rate ranging from 384Kbps to 2Mbps. In the fast-moving state, it still can provide 384Kbps transmission rate. In the low speed moving environment or indoor, it can transfer up to 2Mbps. WCDMA is supported by European manufacturers whose main product is the GSM system, and Japanese companies are more or less involved. The U.S. and European Ericsson, Alcatel Kata, Nokia, Lucent, Nortel and Japan's NTT, Fujitsu, Sharp and other manufacturers support it. This standard proposed the evolution strategy of GSM (2G)GPRS-EDGE¬- WCDMA (3G). The system can be set up in the existing GSM network; this is easier for system providers to transit. In Europe, the GSM system is quite popular which makes
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this standard more suitable to accept. Therefore, WCDMA has inherent advantages from the view of the market.
2.5.2 CDMA2000 CDMA2000 is an extension of 2G’s CDMA, also known as CDMA Multi-Carrier. It is led by the North American Qualcomm. Motorola, Lucent and Samsung also participated in the technology. Now South Korea is the main leader of the standard. The system is derived from the digital standard of the narrowband CDMA One, which could be upgraded from the structure of the original CDMA One to 3G with low construction cost. However, the coverage is not so wide that the supporters of CDMA2000 are less than W-CDMA. But the development process of CDMA2000 standard is currently the fastest. This standard raised the evolution strategy as CDMA¬IS95 (2G)-CDMA2001x-CDMA2003x (3G).In this development process, CDMA2001x is called as 2.5 generation mobile communication technology. The main difference of CDMA2003x and CDMA2001x is on the application of multi-carrier technology. Through the use of three carriers to raise bandwidth, China is using this program to transit over 3G, and has built CDMA IS96 networks.
2.5.3 TD-SCDMA The full name of TD-SCDMA is Time Division-Synchronous Code Division Multiple Access, a standard of wireless communication technology. It was first brought by China and on the basis of Radio Transmission Technology (RTT), with international cooperation China has completed the TD-SCDMA standard which becomes a member of the CDMA TDD standard. TD-SDMA has the characteristics of low radiation, known as ―green 3G‖. This standard will be integrated with intelligent wireless, synchronous CDMA, software radio technology and other leading technologies. And it has unique advantages of spectrum efficiency, flexibility of business support, cost and other aspects. In addition, because of the huge China market, the standard receives the attention of the major telecom equipment vendors. More than half of the world equipment manufacturers have announced support TD-SCDMA standard. The standard is raised 6
without intermediate links of being 2.5 generation, directly to the 3G. It is very practical in the GSM system in the 3G upgrade. Moreover, communications network in military field is the core task for TD-SCDMA as well.
2.5.4 WiMAX WiMAX's full name is the Worldwide Interoperability for Microwave Access, also known as IEEE802.16 wireless metropolitan area network. This technology is combined with license or license-free microwave equipment, due to lower costs, which will expand the market of broadband wireless technology, improve awareness of enterprises and service providers. Because it is also a future part of 4G, so more details of WiMAX will be introduced in 4G.
2.6 Model Structure of 3G Telemedicine Network Based on topological knowledge in Cisco courses and materials of telemedicine, the author constructs a basic 3G network for telemedicine in rural areas. The applications of the new telemedicine are the basic ones. With the latest telemedicine technology, we could have more and better performance. We can see from Figure 2.1 that this 3G network could be divided into three parts. The telemedicine application server, the FTP server, the database server and real-time communication server constitute the core part of telemedicine service platform. Because of the existing firewall which protects security of hospital database, we can gather information and data needed from various hospitals. At the same time, the platform control all schedules and implementation of remote medical activities. The second part is the internal structure of hospital in cities. Hospital primary databases, host computers and internet make up the data mountain of hospitals regardless of them being in rural areas or cities. The firewall here is to project the LAN in hospital from attacks outside the network. It includes access permission, IP control, Network isolation, port shield, virus prevention. The last part consists of two main aspects, 3G environment provided by operators and telemedicine applications in 3G. It includes base situations, 3G gateway server and other basic equipment. 7
Using 3G mobile communication through shared broadcast and a multicast transmission link could achieve high performance mobile communications, to meet the needs of mobile telemedicine activities. Mobile telemedicine terminals use smart phones or laptops with mobile communications to access the Internet through a 3G network. Mobile remote consultation, remote medical monitoring, telemedicine and teaching activities could all come true in terminals in a 3G environment.
Figure 2.1 Topological diagram of 3G telemedicine network 3G mobile telemedicine systems in rural areas is an application system which is integrating a set of multiple technologies. It is based on 3G technology as the core network architecture. 3G technology ensures high-speed data transmission for telemedicine, and can achieve efficient exchange of information which is conducive to real-time telemedicine. After the entire system would be implemented, the patients could get the help from mobile remote medicine. Using audio and video reduces problems caused by only voice description in traditional telemedicine. It is possible to provide rapid and effective emergency plan in a really 8
short time. Doctors and medical resources make a breakthrough of their limits in geographical scope, which enables rural remote areas to access more advanced medical care. The 3G network provides different types of medical care in the same platform, sharing audio and video information to patients to receive better guidance and help. Patients could receive help in the system automatically from an e-expert in a few minutes. It is the most basic emergency plan. Then based on 3G data center handling, according to the real situations reflecting via audio and video, the system will give a preliminary analysis and then continue to switch into subsections. In Figures 2.2 the topological pictures show the process of medical consultation services via a medical Imaging transmission. These are the main applications for telemedicine. The joining technology 3G gives more advantages for both products.
Figure 2.2 The medical Imaging transmission system in 3G telemedicine
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CHAPTER THREE
The Fourth Generation Mobile Data Protocol (4G)
To be technical, 4G stands for ―4th generation‖ mobile data protocol. But as a growing band of 4G users will tell you, it’s all about the speed. Now, what is 4G LTE? LTE stands for Long Term Evolution. It’s a term used for the particular 4G protocol that delivers the fastest mobile Internet experience. Some experts even refer to it as ―true 4G.‖ A 4G LTE network is therefore one that operates at the leading edge of speed and reliability. Using a 4G Smartphone on Verizon’s 4G LTE network means you can download files from the Internet up to 10 times faster than with 3G. With 4G LTE, using the web from your phone becomes as pleasurable as using it from your home computer. To join the 4G revolution, you need to have a Smartphone that is configured to work with a 4G network and a mobile plan like share everything. All 4G phones offered by Verizon will work with its 4G LTE network, the largest in the U.S. These phones will connect automatically with the 4G LTE network, but they can also connect to and use the 3G network (at 3G speed) in places where 4G LTE service is not yet available. So there you have it. 3G speeds laid the groundwork for our increasingly mobile lifestyle, but 4G speeds are truly taking ―mobile‖ to the next level.
For average consumers, '3G' and '4G' are two of the most mysterious terms in the mobile technology dictionary, but they're used relentlessly to sell phones and tablets. If you're shopping for a new phone, the answer isn't clear-cut, and you shouldn't always go for the higher number. Our primer will help explain which technology to pick.
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3.1 Long Term Evolution 3.1.1 Background LTE is using Orthogonal Frequency Division Multiple Access (OFDMA) in downlink and Single Carrier Frequency Division Multiple Access (SC-FDMA) in uplink as the multiple access scheme .These multiple access solutions provide orthogonally between the users, reducing the interference and improving the network capacity. The resource block allocation in the frequency domain takes place with a resolution of 180 kHz both in uplink and in downlink. Packet scheduling on frequency dimension is one reason for the high LTE capacity. The uplink single carrier transmission has specific allocation to be used while the downlink can use resource blocks freely from different parts of the spectrum. The uplink single carrier solution is also designed to allow efficient terminal power amplifier design, which is relevant for the terminal battery life. The LTE solution enables spectrum flexibility where the transmission bandwidth can be selected between 1.4 MHz and 20 MHz depending on the available spectrum.
3.1.2 What is LTE? LTE actually stands for ―long term evolution‖, and its full name is 3GPP LTE, with the 3GPP standing for the 3rd Generation Partnership Project, which has been developing the technology's release documents. Often, LTE is marketed as 4G technology by companies that package it as part of their wireless or mobile service, but the standard is better thought of as ―3.9G‖ as it does not yet meet the requirements set out by the ITU-R for 4G, which includes minimum upload and download rates for networks and defines how connections must be established. A new version of LTE technology, LTE Advanced, does satisfy the requirements of a true 4G network and is expected within the next year. This technology got its start in 2004, proposed by NTT DoCoMo of Japan. Studies began officially in 2005 and by 2008 the first standard has been finalized. It went live in Oslo and Stockholm in 2009 as a form of data connection with a USB modem, supported by carrier TeliaSonera. In 2011, MetroPCS and Verizon migrated to this technology in North America. Initially, providers such as Sprint, Bell, Verizon and even MetroPCS, which run on CDMA 11
networks had plans to upgrade to a rival standard known as UMB, but have now decided to throw their support behind LTE and LTE Advanced. So, what exactly is LTE? It's based on GSM/EDGE and UMTS/HSPA network technologies, and provides an increase to both capacity and speed using new techniques for modulation. It provides peak download rates of 300 megabits per second, upload rates of 75 megabits per second and a transfer latency of less than five milliseconds. It can also manage multi-cast and broadcast streams and handle quick-moving mobile phones. Its Evolved Packet Core (EPC), IP-based network architecture, allows for seamless handovers for voice and data to older model cell towers that use GSM, UMTS or CDMA2000 technology. In addition, it can scale from 1.4 MHz to 20 MHz carrier bandwidths and supports both time-division and frequency division duplexing. Overall, the new architecture of LTE technology means lower operating costs along with greater overall data and voice capacity.
3.1.3 The Issues Surrounding LTE One emerging issue related to the use of the LTE standard is that of voice communication. All GSM, UMTS and CDMA2000 networks are circuit switched, but the ITU-R standard for a 4G network calls for exclusively packet switching through an IP network, something LTE supports. This means that carriers switching to LTE will need to alter their voice call network to support the new switching. Currently, most providers use what is known as circuit switched fallback (CSFB), where LTE provides only data services and voice calls ―fallback‖ to being circuit switched. This is easy to setup and operate, but does mean a longer call setup time. The most likely candidate for future packet switched voice calls revolves around the use of VoLTE or Voice Over LTE, which uses the IP Multimedia Subsystem network. LTE offers a number of benefits over current 3G technology and are already being marketed as ―4G‖ by many providers, despite the fact that is does not yet meet all ITU-R requirements. Nonetheless, this standard is expected to form the backbone of many 4G mobile networks.
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3.2 Understanding WiMAX Technology Standards 3G or ―third generation‖ Internet connectivity standards are quickly being supplanted by a fourth generation or ―4G‖ network, although this has yet to reach its full potential. A number of standards have been developed for this new Internet market, among them WiMAX technology. But what is WiMAX, and does it help users access the Internet with greater ease? WiMAX actually stands for Worldwide Interoperability for Microwave Access, and is a wireless communication standard. Of the standards currently being developed for 4G it is the closest in practice to current Wi-Fi, though it provides several notable advantages. WiMAX was developed in 2001 and is described by the WiMAX forum as "a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL". This ―last mile‖ refers to the often difficult process of getting access to a consumer from a local data station, be it in the form of a telephone cable, wireless device or other broadcasting technology.
What is WiMAX? While it operates using many of the same fundamental principles as Wi-Fi networks, it offers a far greater signal range than the 100 feet provided by most conventional Wi-Fi modems. Instead, WiMAX boasts a 30 mile radius, large enough to cover portions of major cities. In addition, this standard is intended to provide 30 to 40 megabits per second as a transfer rate, with a 2011 update to the standard yielding up to 1 gigabit per second at fixed points. It should be noted, however, that bandwidth on a WiMAX network is not exclusive to users and instead must be split, meaning that while higher speeds may be advertised, the number of users can lower transfer rates in practice. WiMAX uses IEEE 802.16 wireless network standards that are interoperable, as compared to the IEEE 802.11 standards used by wireless LANs. The original standard, as mentioned above, was developed in 2001 and borrowed some of its technology from a service known as WiBRO, used in South Korea. This standard is sometimes referred to as ―Wi-Fi on steroids‖ for its ability to far outperform Wi-Fi transfer rates and signal distance, and gained significant ground in the market
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with the deployment of Mobile WiMAX, based on 802.16e-2005, and which led to the 802.16e2011 revision and higher data transfer rates.
The WiMAX Potential WiMAX has a number of front-line uses, including at-home and mobile Internet access. Because of its large radius and relatively low cost to implement when compared to 3G, xDSL or HFC, the technology can not only compete in a local market but also be used for last-mile access in remote locations. In addition, the standard can be used as backbone for cellular technology, either by replacing current technologies or acting as an overlay in order to increase capacity. It can also be used to provide ―triple-play‖ service, which involves the deployment of two bandwidth-intensive operations and one less bandwidth-intensive operation over a single connection. This can include, for example, high speed Internet access, Internet television and a standard phone line. This standard does suffer from the problem of lower bit-rates farther from its source, meaning that those at the outer edges of its range receive lower data transfer rates. Tests in Perth, Australia showed that users on the edge of the cell range received between one and four megabits per second, while those closer to the source received approximately 30 megabits per second. WiMAX is viable standard for meeting 4G data transfer requirements, but will face competition from other standards on the market, most notably LTE technology, which is already being using by several cell phone companies. For average consumers, '3G' and '4G' are two of the most mysterious terms in the mobile technology dictionary, but they're used relentlessly to sell phones and tablets. If you're shopping for a new phone, the answer isn't clear-cut, and you shouldn't always go for the higher number. Our primer will help explain which technology to pick.
3.3 System Architecture The simplified overview of LTE architecture is given in Figure 4.1. The major component is gateway (GW), which handles both packet data network (PDN) and serving gateway 14
functionality. The common point for all access technologies is PDN gateway that also providing a stable IP, regardless of mobility within or between access technologies. The serving gateway is the anchor point for intra-3GPP mobility. The MME functionality is to facilitate network deployment, independent technology evolution, and fully flexible scaling of capacity. The interoperability is covered with the help of Serving GPRS Support Node (SGSN); it deals with GSM/WCDMA system. This includes interfaces to the MME for transferring context and establishing bearers when moving between accesses, and to the gateway for establishing IP connectivity with user equipment (UE). The architecture also allows for a common packet core network for GSM, WCDMA/HSPA and LTE by combining the SGSN and the MME in the same node.
Figure 3.1 Architecture of LTE.
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3.4 Physical Layer General Description
Following are the brief description of physical channels. 3.4.1 Downlink Physical Channel Three different types of physical channels are defined for the LTE downlink. One common characteristic of physical channels is that they all convey information from higher layers in the LTE stack.
3.4.2 Physical Downlink Shared Channel The PDSCH is utilized basically for data and multimedia transport. It therefore is designed for very high data rates. Modulation options include QPSK, 16QAM and 64QAM results for very high data rate. Spatial multiplexing is also used in the PDSCH.
3.4.3 Physical Downlink Control Channel The PDCCH gives UE-specific control information. Robustness rather than maximum data rate is therefore the chief consideration. The PDCCH is mapped onto resource elements in up to the first three OFDM symbols in the first slot of a sub frame.
3.4.4 Physical Broadcast Channel (PBCH) Carries the all-important system information in Master Information Block (MIB).
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3.4.5 Physical Control Format Indicator Channel (PCFICH) Indicates number of control channel symbol per downlink subframe. Uplink channel is briefly overview from following section.
3.5 Uplink Physical Channel Uplink physical channels are used to transmit information originating in layers above the PHY. Defined UL physical channels are as follows.
3.5.1 Physical Uplink Shared Channel (PUSCH) Resources for the PUSCH are allocated on a sub-frame basis by the UL scheduler. The PUSCH may employ QPSK, 16QAM or 64QAM modulation.
3.5.2 Physical Uplink Control Channel (PUCCH) The PUCCH carries uplink control information. PUCCH contains control information including ACK/NACK, channel quality indication (CQI), HARQ and uplink scheduling requests.
3.6 Basic Principle of OFDMA Orthogonality is maintained in OFDM despite their close spacing. It also eliminated mutual inter-carrier interference (ICI). It provides high achievable spectral efficiency. Further benefits of OFDM include its robustness to multipath fading and elimination of Inter-Symbol Interference.
In LTE, OFDMA uses fixed 15 kHz, subcarriers frequency spacing. The
modulated bits are converted from serial to parallel which becomes the input of IFFT block, as shown in Figure 3.2. The inputs to the IFFT block are the subcarriers converted into the time domain signal.
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Figure 3.2 OFDMA system block diagram.
3.7 LTE-Downlink Channel The communication with UE and eNode B is done using downlink transmission. UE estimate the downlink radio channel in order to have demodulation performance of information-bearing parts of downlink signal.
3.7.1 Physical Downlink Control Channel (PDCCH) A PDCCH carries a message known as Downlink Control Information (DCI), which includes resource assignments and other control information for a UE or group of UEs. In general, several PDCCHs can be transmitted in a subframe.
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3.7.2 Physical Harq Indicator Channel (PHICH) The PHICH carries the HARQ (Hybrid Adaptive Repeat and Request) ACK/NACK, (Acknowledgement /Negative Acknowledgement) which indicates whether the eNodeB has correctly received a transmission on the PUSCH (Physical Uplink Shared Channel).
3.7.3 Physical Broadcast Channel (PBCH) PBCH carries the system information needed to access the system. PBCH periodically sends (every 40 milliseconds) system identification and access control parameters.
3.7.4 Physical Downlink Shared Channel (PDSCH) PDSCH is the main data bearing downlink channel in LTE. It is used for all user data, as well as for broadcast system information which is not carried on the PBCH, and for paging messages – there is no specific physical layer paging channel in the LTE system.
3.8 LTE-Uplink Channel UE transmitting Sounding Reference Signals SRS that estimate information from LTE uplink channels. SRS is used for channel quality determination to enable frequency- selective scheduling on the uplink.
3.8.1 Physical Uplink Control Channel (PUCCH) Control signaling (consisting of ACK/NACK, CQI/PMI and RI) is carried by the PUCCH when no PUSCH resources have been allocated. 6.2.2 Control Signaling on PUSCH
The
PUSCH supports resource allocation for both frequency-selective scheduling a frequency-diverse transmissions.
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3.8.2 Physical Random Access Channel PRACH carries the random access preamble. The network configures the set of preamble sequences the UE is allowed to use. There are 64 preambles available in each.
3.8.3 Demodulation Reference Signal (DMRS) The reference signal transmitted in either PUSCH, PUCCH whenever they are transmitted. Provides reference coherent demodulation of Uplink transmissions.
3.8.4 Sounding Reference Signal (SRS) UE transmits, to help the network estimate the Uplink channel. Also, used for frequency selective allocation, Uplink power control, or mode switching for transmit diversity.
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CHAPTER FOUR
3G and 4G Explained
4.1 3G and 4G Explained
First things first, the "G" stands for a generation of mobile technology, installed in phones and on cellular networks. Each "G" generally requires you to get a new phone, and for networks to make expensive upgrades. The first two were analog cell phones (1G) and digital phones (2G). Then it got complicated.
Third-generation mobile networks, or 3G, came to the U.S. in 2003. With minimum consistent Internet speeds of 144Kbps, 3G was supposed to bring "mobile broadband." There are now so many varieties of 3G, though, that a "3G" connection can get you Internet speeds anywhere from 400Kbps to more than ten times that. New generations usually bring new base technologies, more network capacity for more data per user, and the potential for better voice quality, too. 4G phones are supposed to be even faster, but that's not always the case. There are so many technologies called "4G", and so many ways to implement them, that the term is almost meaningless. The International Telecommunications Union, a standards body, tried to issue requirements to call a network 4G but they were ignored by carriers, and eventually the ITU backed down. 4G technologies include HSPA+ 21/42, WiMAX, and LTE (although some consider LTE the only true 4G of that bunch and some people say none of them are fast enough to qualify.) There are many different ways to implement LTE, too, so you can't assume all LTE speeds are the same. Carriers with more available radio spectrum for LTE can typically run faster networks than carriers with fewer spectrums, for instance.
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This confusion is why we run our annual Faster Mobile Network story, which tests 3G and 4G networks in 30 cities nationwide. In this year's tests, we generally found that on speed alone AT&T's 4G LTE network was the fastest, followed by T-Mobile LTE, Verizon LTE, T-Mobile HSPA+, Sprint LTE, AT&T HSPA, Verizon 3G and finally Sprint 3G. As Sprint ramps up its faster "Spark" LTE network, we expect its LTE speeds to rise to competitive levels.
4.2 When to Go For 4G In 2013, almost everyone should have a 4G phone. Verizon now has nationwide 4G LTE coverage. T-Mobile and MetroPCS have nationwide HSPA+ 42 and growing LTE networks. AT&T has broad LTE coverage. Sprint is still building out LTE, but by next year the carrier aims to be comprehensive. There's one thing to watch out for, though. Some carriers, such as FreedomPop, are still selling phones that run on Sprint's old WiMAX system. That system is deteriorating and will be turned off at the end of 2015. The new LTE system will only expand. So we recommend buying LTE devices from Sprint, not WiMAX devices. If possible, the devices should also support Sprint's new, faster "Spark" LTE system, not all of Sprint's LTE phones do. If you like to surf the Web and especially stream video, 4G can be heaven. If you connect a laptop to your mobile link, 4G makes a huge difference. In general, anything involving transferring large amounts of data gets a big boost from 4G. Watch out for the data limits on your service plan, though; it's easy to use up a lot of data very quickly with 4G. If you have a 3G phone and you've been frustrated with slow data, 4G may be the solution. 4G won't solve any dropped call problems, though, as all calls will be made over older networks until carriers switch to voice-over-LTE during the next few years. Finally, if you want to future-proof yourself, get a 4G phone. 4G coverage is only going to get better, and that's where the carriers are spending most of their money right now. You can assume that all 4G phones also support your carrier's 3G and 2G networks as well. 22
4.3 Should You Even Consider 3G?
There are a few reasons you might still settle for a 3G phone. If your phone is mostly for voice use, you have no need for 4G data. Save money and save battery life by choosing a device without the high-speed network. If you live in an area that doesn't have 4G coverage, there's no advantage to a 4G phone. In fact, you'll have serious battery life problems if you buy an LTE phone and don't disable 4G LTE, as the radio's search for a non-existent signal will drain your battery quickly. If you're strapped for cash and buying a phone off contract, you may have to settle for 3G to save money. In that case, make sure to get the fastest 3G phone possible. On Verizon and Sprint, you want to check that it supports "EVDO Rev A." On T-Mobile and AT&T, you want the highest class of HSPA+ possible: if not 42 or 21, then 14.4.
4.4 The Difference On the surface, the difference between 3G and 4G is pretty simple. The ―G‖ is short for generation, so 3G and 4G represent the third and fourth generations of mobile broadband Internet. As a rule, provided that you’re on the same carrier, a 4G connection will be faster than a 3G one. However, that doesn’t necessarily mean that a 4G network of one carrier will always be faster than the 3G network of another. To be advertised as 3G, a network is required to meet a set of technical standards for speed and reliability, and must offer peak data transfer rates of at least 200 kilobits per second. The first networks that met this standard rolled out in the U.S. around 2003, and as smart phones began to gain more widespread use, demand for faster mobile broadband access saw a corresponding rise. In just a few short years, this push for faster data rates drove the standard forward, and today 3G networks can be anywhere from 200 kbps to dozens of times that fast.
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To be advertised as 4G, a network must offer peak data rates of at least 100 megabits per second for high mobility communication (users in cars, trains, etc.), and at least 1 Gigabit per second for low mobility communication (pedestrians and stationary users). Not all 4G networks are created equal though – they come in a variety of different flavors, and some are faster and more widely deployed than others. The most common deployments are LTE, WiMAX, and HSPA+, but LTE is undoubtedly the most widely used amongst major US carriers. It’s also worth noting that each new generation of wireless broadband typically requires your cell phone provider to make upgrades on their towers, and therefore requires you to upgrade your phone so that it can send/receive signals through the new infrastructure. A 3G phone cannot communicate through a 4G network, but newer generations of phones are practically always designed to be backward compatible, so a 4G phone can communicate through a 3G or even 2G network.
4.5 When to go with 3G You might want to skip the 4G route and opt for a 3G phone if:
Your area doesn’t have 4G network coverage. If you don’t have the network, there’s no point in buying a 4G phone, since it wouldn’t be able to communicate with any 4G cell towers to relay the signal. That being said, most 4G phones are backward compatible, meaning they can still connect to 3G towers when a 4G network isn’t available. If you’re anticipating 4G expanding into your area, a 4G phone might not be a bad choice.
You don’t really use a lot of data-hungry applications. If you don’t plan on streaming lots of music and video from the web, you probably don’t need the blazing fast speeds offered by 4G. Most apps for basic stuff like GPS, weather, email, and social networking will work just fine on a 3G connection.
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4.6 When to go with 4G You might want to consider getting a 4G phone if:
You want a newer model cell phone. 4G networks are becoming pretty standard, so most of the newest and most cutting-edge phones (Samsung Galaxy S3, iPhone 5, etc) are typically 4G phones.
Your carrier has a solid 4g network in your area. If its there, you might as well take advantage of it.
You use lots of data, and could benefit from faster speeds. If you like to watch YouTube on your way to work, stream Spotify everywhere you go, and you rely on a boatload of internet-connected applications to make it through the day, then go with a 4G connection. Having blazing-fast internet in your pocket at all times is insanely useful, and data plans usually cost the same amount regardless of whether they’re on 3G or 4G.
4.7 Understanding 4G Technology Standards The term ―4G‖ is being thrown around a great deal these days in reference to a new speed standard in Internet connectivity, but what exactly does the term mean? What is 4G? Most users are familiar with ―3G‖ standards, as most smart phones use this communications standard. 3G simply means ―third generation‖ in reference to the evolution of data transfer technologies. The first generation of mobile technology (1G) came in 1981 with analog transmission, and in 1992 was 2G appeared in the form of digital information exchange. 3G made its debut in 2001, and included multi-media support along with a peak transfer rate of at least 200 kilobits per second. True 4G support is expected within the next few years. It is no surprise, then, that 4G means ―fourth generation‖ and represents a number of improvements over the 3G technology currently being used.
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4.7.1 Who Sets the 4G Standards 4G technology is meant to provide what is known as ―ultra-broadband‖ access for mobile devices, and in March of 2008 the International Telecommunications Union-Radio communications sector (ITU-R) created a set of standards that networks must meet in order to be considered 4G, known as the International Mobile Telecommunications Advanced (IMTAdvanced) specification.
4.7.2 What are the 4G Standards? First, 4G networks must be based on an all Internet protocol (IP) packet switching instead of circuit-switched technology, and use OFMDA multi-carrier transmission methods or other frequency-domain equalization (FDE) methods instead of current spread spectrum radio technology. In addition, peak data rates for 4G networks must be close to 100 megabit per second for a user on a highly mobile network and 1 gigabit per second for a user with local wireless access or a nomadic connection. True 4G must also be able to offer smooth handovers across differing networks without data loss and provide high quality of service for next-gen media. One of the most important aspects of 4G technology is the elimination of parallel circuitswitched and packet-switched network nodes using Internet Protocol version 6 (IPv6). The currently used standard, IPv4, has a finite limitation on the number of IP addresses that can be assigned to devices, meaning duplicate addresses must be created and reused using network address translation (NAT), a solution that only masks the problem instead of definitively solving it. IPv6 provides a much larger number of available addresses, and will be instrumental in providing a streamlined experience for users.
4.8 The 4G Confusion There are a number of providers currently on the market claiming they can answer the ―what is 4G?‖ question, but first-release versions of ―4G‖ networks do not meet the standards set out by 26
the ITU-R. Generally, these networks are considered stop-gap measures until new versions of existing technology can be deployed, but are often still advertised as being 4G. These almost-4G networks are often called ―3.9G‖ because they differ significantly from what is available on the market but do not quite meet ITU-R standards. In many cases, these 3.9G systems are based on new radio-interface paradigms, use different frequency bands than existing networks and are not backwards compatible with 3G solutions. Currently, there are two technologies that have been submitted to the International Telecommunication Union (ITU) as viable 4G candidates: LTE Advanced, which was standardized by the 3GPP and 802.16m, standardized by the IEEE (also known as WinMAX). The standardized versions of these technologies were ratified by the ITU in spring 2011, but are still not ready for large-scale implementation. 4G represents a significant evolution over existing 3G standards, most notably in the removal of IP address limitations, increased data transfer rates and smooth handovers of clients over heterogeneous networks, but fully compliant technology is still in development.
4.9 Understanding LTE Technology Standards The market for wireless data transfer is quickly evolving as global rather than local solutions are pursued – solutions offering robust data transfer rates, predictable spikes in traffic and are interoperable. One of the fastest-growing standards in the competition for ownership of the new fourth generation or ―4G‖ market is LTE technology, which promises a number of improvements over current mobile and data terminal service.
4.10 Evolution of Different Technical Standards The following figure shows the evolution history of different technologies. The GSM network must first upgrade to GPRS, then continue to upgrade to EDGE, or from GPRS then evolves to WCDMA or TD-SCDMA, to achieve the 3G standard. If it continues to evolve, it is 27
along the HSDPA and HSUPA, and then reaches over 4G standards. In addition, Japanese PDC is through direct evolution to WCDMA, and then continues. The evolution line of CDMA is firstly to CDMA2000-1X, and then upgraded to 1XEV-DO, or 1XEV-DV, and next to CDMA2000-3X, at last moving to the 4G.
Figure 4.1 Evolution of different technical standards
According to three steps development plan of 3G market, 3G multimedia services will enter the third stage of development in less than 10 years. Nowadays the global coverage of the 3G network has been basically completed and more than 25% of the global population using third generation mobile communication systems. In developed countries, 3G services have penetrated more than 80% of the markets. Then there is the need of a new generation of systems to further improve service quality.
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CHAPTER FIVE
Comparison of 3G Wireless Networks and 4G Wireless Networks
5.1 Introduction: 3G is also called third generation. It is named as such because it is the third generation of the standards of telecommunication hardware. It is also the general technology for mobile networking, passing the recent 2.5G. The technology is founded on the ITU or International Telecommunication Union group of standards which belongs to the IMT-2000. 4G is the fourth generation of mobile phone mobile communications standards. It is a successor of the third generation (3G) standards. A 4G system provides mobile ultra-broadband Internet access.
5.2 Background difference: In 3g technology which is founded on the ITU or International Telecommunication Union group of a standard which belongs to the IMT-2000 use W-CDMA technology. It allows operators to provide users a bigger range of the latest services, as it gets bigger network capacity via heightened spectral efficiency. The included services are video calls, wide-area wireless voice telephone and broadband wireless information all included within the mobile environment. Whereas 4G technology which was Started within cable television industry in 2009 which make users to explore new downloading speeds and capabilities. The utilization of LTE mobile broadband technology is an opportunity for the corporation to expand its horizons into 4G territory, upstaging current 3G capabilities. The necessity for 4G networks is associated with the increased utilization of data websites such as You Tube and Facebook, which require tremendous bandwidth in order to be used successfully.
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3G Stands for 3rd Generation While 4G Stands for 4th Generation: 3G is currently the world’s best connection method when it comes to mobile phones, and especially mobile Internet. 3G stands for 3rd generation as it  is just that in terms of the evolutionary path of the mobile phone industry. 4G means 4th generation. This is a set of standard that is being developed as a future successor of 3G in the very near future. Architectural difference: both the Figures below provide the key components of these two architectures.
Figure 5.1 Architecture
Several key differences in a LTE network enable more flexibility in its architecture than in a 3G. A functional representation of 3G network architecture is shown in Figure 5.1 . In this network, the Base Terminal Station (BTS)/Nodes aggregate the radio access network (RAN) traffic and transport it over a mobile Comparison of 3G Wireless Networks and 4G Wireless Networks:
Backhaul network to the Radio Network Controllers (RNCs)/Base Station Controller (BSCs). Typically this transport is over T1/E1 copper facilities. If fiber is available at or near the cell site, then the cell traffic is transported over SDH/SONET rings or, more recently, a carrier Ethernet network when the eNodeBs are equipped with IP/Ethernet interfaces. The bearer traffic from a number of RNCs/BSCs is multiplexed at the Mobile Telephone Switching Office (MTSO) and
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then transported via direct tunneling to the Gateway GPRS Serving Nodes (GGSNs) in the hub data center. This transport is normally over a SDH/SONET ring or a carrier Ethernet network. This tiered aggregation and transport structure lends itself to a point-to-point network topology to minimize both the amount of aggregation equipment required and the transport backhaul expense. In a 3G pre-Release 8 network, the RNCs and SGSNs are designed to support both the signaling and bearer plane processing and bandwidth requirements. The emphasis in the design for these network elements is in providing the processing necessary to support the high subscriber counts and Packet Data Protocol PDP contexts as the bandwidth requirements for delivery of the initial 3G data services (text and e-mail) were not significant. Since the data services that typically ran over these systems is not real-time neither QoS nor latency was an issue. Therefore, the placement of these elements is usually in locations that primarily meet the PDP context and network latency requirements. Thus, the current 3G packet core architecture is typically a centralized network design with the GGSNs deployed in major data centers, and all the data services are backhauled from the SGSNs which are strategically deployed in regional serving offices. Because the aggregate bandwidth for these services did not increase significantly until the past few years, the backhaul transport costs were manageable and could be supported with leased TDM or lower rate OC-n/STM-n interfaces.
Figure 5.2 Architecture
Above fig 5.2 provides a high-level functional representation of a LTE/4G network. This network is composed of three major sub-networks: the Evolved Universal Terrestrial Radio Access Networks (eUTRAN),which provides the air interface and local mobility management of the user equipment (UE), the evolved packet core (EPC), and the broadband backhaul network 31
that provides the aggregation of cell traffic and transport back to the EPC. The 3GPP LTE standards defined he EPC as a set of logical data and control plane functions that can be implemented either as integrated or as separate network elements. The four EPC functions are: the Serving Gateway (SGW), the Packet Data Network Gateway (PGW) that supports the data or bearer traffic; and the Mobility Management Entity (MME) and the Policy Charging and Rules Function (PCRF) which support the dynamic mobility management and policy control traffic. The backhaul network either is owned by the wireless operator or is leased from a third party backhaul access provider. Any number of transport technologies can be used for backhaul including packet microwave, packet optical, Carrier Ethernet, IP/MPLS, GPON and xDSL.
5.3 Network. 3G technologies are in widespread use while 4G compliant technologies are still in the horizon: The biggest difference between the two is in the existence of compliant technologies. There are a bunch of technologies that fall under 3G, including WCDMA, EV-DO, and HSPA among others. Although a lot of mobile phone companies are quick to dub their technologies as 4G, such as LTE, WiMAX, and UMB, none of these are actually compliant to the specifications set forth by the 4G standard. These technologies are often referred to as Pre-4G or 3.9G.
5.3.1 4G Speeds are Much Faster Compared to 3G: 4G speeds are meant to exceed that of 3G. Current 3G speeds are topped out at 14Mbps downlink and 5.8Mbps uplink. To be able to qualify as a 4G technology, speeds of up to 100Mbps must be reached for a moving user and 1Gbps for a stationary user. So far, these speeds are only reachable with wired LANs. The fourth generation is faster, it is said to be four times faster than its predecessor. This allows for a connection speed more comparable to DSL and home cable networks. It is great news for those completing work and accomplishing important tasks away from their home and office. When uploading large documents and
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communicating via the internet, a fast connection is important. Whereas 3g doesn’t favor such speed as compared to that of 4G.
5.3.2 3G is a Mix of Circuit and Packet Switching Network While 4G is Only a Packet Switching Network: Another key change in 4G is the abandonment of circuit switching. 3G technologies use a hybrid of circuit switching and packet switching. Circuit switching is a very old technology that has been used in telephone systems for a very long time. The downside to this technology is that it ties up the resource for as long as the connection is kept up. Packet switching is a technology that is very prevalent in computer networks but has since appeared in mobile phones as well. With packet switching, resources are only used when there is information to be sent across. The efficiency of packet switching allows the mobile phone company to squeeze more conversations into the same bandwidth. 4G technologies would no longer utilize circuit switching even forvoice calls and video calls. All information that is passed around would be packet switched to enhance efficiency.
5.3.3 Network: Another difference between the two is the network. When the 3G was introduced, cell phone users were finally able to talk and access data at the same time and with higher data rates. This allowed for a better full service for cell phone users wishing to access the internet. And what is even greater is the 4G data rates are expected to be even higher. Users will have the capability of accessing more data at higher speeds while talking on their cell phone. In addition, the fourth generation permits more data transmission of such services as games and multimedia. It also allows a larger amount of internet support.
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5.4 Bandwidth: The next difference between the third and fourth generation to is bandwidth. At first glance, the bandwidth of both 3G and 4G are the same, numbered at between 5 and 20 MHz However, the rate of data is what makes the difference between the two. While the data rate of the third generation only goes up to 2 Mbps, the fourth goes all the way up to between 100 Mbps to 1 Gbps.
5.5 Design Specification: The 3G technology provides both circuit design and packet design. Circuit design, being the oldest, has greater ability to hold the connection for a longer duration. On the other hand the packet design is a wireless technology and is the core part of internet data transmission. The combination of these two patterns helps 3G technology to perform better and faster. However, the 4G technology is kept free from circuit design with an intention to gives nanosecond wings to data transfer and so has packet design only.
5.5.1 Data Transmission Rate (Performance Delivered): 3G system is based on wideband CDMA that operates in 5 MHz of bandwidth and can produce download data rates of typically 384 kb/s under normal conditions and up to 2 Mb/s in some instances.3g phone standards have been expanded and enhanced to further expand data speed and capacity. The WCDMA phones have added high speed packet access (HSPA) that use higher level QAM modulation to get speeds up to 21 or 42 Mb/s downlink (cell site to phone) and up to 7 and/or 14 Mb/s uplink (phone to cell site).whereas in 4G
also known as LTE uses a
completely different radio technology. Instead of CDMA, it uses orthogonal frequency division multiplexing (OFDM) and OFDM access. This modulation technique divides a channel usually 5, 10 or 20 MHz wide into smaller sub channels or subcarriers each 15 kHz wide. Each is modulated with part of the data. The fast data is divided into slower streams that modulate the subcarriers with one of several modulation schemes like QPSK or 16QAM. It also defines
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multiple input multiple output (MIMO) operation that uses several transmitter-receiver-antennas. The data stream is divided between the antennas to boost speed and to make the link more reliable. Using OFDM and MIMO lets LTE deliver data at a rate to 100 Mb/s downstream and 50 Mb/s upstream under the best conditions. In 4G the theoretical upper data rate is 1 Gb/s. That remains to be seen in practice.
5.5.2 Quality of Service: In 3G, network based QoS depends on following factor to provide a satisfactorily service as: Throughput, Packet Loss Rate, Packet Loss Rate, reliability and delay. Where as in 4G With respect to network quality, many telecommunications providers are promising that there will be enhanced connectivity, and the quality of data that is transmitted across the network will be of the highest possible quality. The main challenge that 4G networks are facing is integrating nonIP-based and IP-based devices. It is known that devices that are not IP address based are generally used for services such as VoIP. On the other hand, devices that are IP address based are used for data delivery. 4G networks will serve both types of devices.
5.5.3 Service and Billing: 3G networks that are capable of supporting an ever-increasing variety of data services from streaming video, to gaming, to proprietary business applications, to mobile commerce transactions for tangible goods and services. However, as 3G finally makes it into the mainstream, its success is inextricably linked to how the CSPs (Communications Service Providers) charge and bill for services in ways that are both intuitive and acceptable to the end user while also being relevant to the CSP’s costs and billing capabilities. Where as in 4G managing user accounts and billing them has become much more complicated with 4G networks. This is mainly due to heterogeneity of 4G networks and the frequent interaction of service providers.
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5.5.4 Features and Capabilities: 3G has features with Speed of mobile communication in 3G ranges from 600-800 Kbit/sec. Also it provides high quality wireless sound and facilitates with global roaming. It accommodates distance surveillance and enables mobile TV. Whereas the ambitious goal of 4G is to allow everyone to access the Internet anytime and everywhere. The provided connection to Internet will allow users to access all type of services including text, databases, and multimedia. 4G will also provide higher bandwidth, data rate, lower authentication overhead, and will ensure the service is constantly provided to the user without any disruption. Comparison of 3G Wireless Networks and 4G Wireless Networks In Table:
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CHAPTER SIX
Migration to 4G Networks
6.1 Migration to 4G Networks Smooth 2G/3G to 4G migration without a ―forklift‖ upgrade – in a single common core platform.
Fast and seamless transition to Evolved Packet Core (EPC), all-IP core network that supports higher throughput, lower latency, and mobility between 3GPP and non-3GPP radio Access technologies.
Core network solution that optimizes backhaul.
Converged mobility and policy management so operators can choose any access technology without a complete overhaul of existing IP core or IP core overlay
Intelligence in the network to deliver higher bandwidth multimedia services – interacting and understanding key elements within the multimedia core
Over the past two decades, the way people communicate, stay informed, and are entertained has changed dramatically. There have been two major technologies driving this change: the Internet and mobile wireless communication. We have grown accustomed to the wealth of information available through the Internet and the mobility provided with wireless communications. Now these two forces are merging to enable the mobile Internet. With this convergence, mobile data services have grown significantly each year.
However, people have a certain expectation for their Internet experience that the mobile wireless environment has not fully met since the speed at which they can access their services has been limited. Mobile operators realize if they are to succeed in today’s communications landscape, they must address the quality of experience for their users. As a result, they are deploying 37
broadband network technologies, such as 3G or third generation and enhanced 3G, including UMTS, HSPA, and CDMA2000 1xEV-DO Rev A. Going forward, mobile operators will continue to evolve their networks to improve the user experience and service opportunities. One such evolutionary technology is the 3GPP Long Term Evolution (LTE) specification. Designated as a 4G or fourth generation mobile specification, LTE is designed to provide multi-megabit bandwidth, more efficient use of the radio network, latency reduction, and improved mobility. This combination aims to enhance the subscriber’s interaction with the network and further drive the demand for mobile multimedia services. With wireless broadband, people will more readily access their Internet services, such as on-line television, blogging, social networking, and interactive gaming—all on the go. Changes in mobile communications have always been evolutionary, and the deployment of LTE will be the same. It will be a transition from 3G to 4G over a period of several years, as is the case still with the transition from 2G to 3G. As a result, mobile operators must look for strategies and solutions that will enhance their existing 3G networks, while addressing their 4G deployment requirements without requiring a ―forklift‖ upgrade.
Specifically, mobile operators need the multimedia core network to be readily upgradeable to the requirements of another 4G architecture called Systems Architecture Evolution Solutions already deployed in the market may include many of the elements required of the 4G network, including integrated intelligence, simplified network architecture, high bandwidth performance capabilities, and enhanced mobility. In order to avoid a costly replacement of the existing systems, only solutions capable of supporting multiple functions in a single node through a software upgrade will protect today’s investment for tomorrow’s network.
6.2 Evolving the Packet Core Radio access solutions are a primary consideration of the LTE deployment strategy, as it impacts the mobile operators’ most valued asset, spectrum. As an equally important part of this equation, the multimedia core network will play a central role in enhancing mobility, service 38
control, efficient use of network resources, and a seamless migration from 2G/3G to 4G. As a result, SAE calls for a transition to a ―flat,‖ all-IP core network, called the Evolved Packet Core (EPC) that features a simplified architecture and open interfaces as defined by the 3GPP standards body. A key EPC goal is to enhance service provisioning while simplifying interworking with non-3GPP mobile networks. The standards promise an all-IP core network with a simplified and flattened architecture that supports higher throughput, lower latency, as well as support for mobility between 3GPP (GSM, UMTS, and LTE) and non-3GPP radio access technologies, including CDMA, WiMAX, WiFi, High Rate Packet Data (HRPD), evolved HRPD (eHRPD), and ETSI-defined TISPAN networks. As a result, mobile operators are looking for the best multimedia core solutions to deliver an optimum user experience and build an efficient network. Key considerations for the multimedia core network include:
6.3 Upgrade Paths to Wireless Broadband LTE is the next step on the migration path to wireless broadband.
Figure 6.1 Upgrade Paths to Wireless Broadband
Integration of intelligence at the access edge— As a greater variety of services and user types cross the mobile network, it is critical to have greater network and subscriber intelligence. Through this intelligence, including Quality of Service (QoS) and policy enforcement, mobile operators will better understand individual users and their transactions and be able to shape the service experience and optimize network efficiency.
Simplified network topology—In order to effectively deliver the enhanced performance of LTE, the network will need to be simplified and flattened with a reduction of elements 39
involved in data processing and transport.
Optimized backhaul—With the introduction of 4G, the transport backhaul is a key consideration that many are realizing after the fact. It is very important to deploy a core network solution that is flexible enough to offer smooth migration from centralized (longer backhaul) to distributed (shorter backhaul) core network nodes.
Converged mobility and policy—Maintaining the subscriber session is an important consideration during 4G to 2G/3G mobility events. Additionally, unified policy management in the network is very important to perform efficient service delivery over mixed 4G and 2G/3G networks. Due to these considerations, it is important to deploy a core network based on a single mobility and policy control paradigm.
Increased performance characteristics—Clearly the intent of LTE is to improve the performance and efficiency of the network. In order to realize the full potential of LTE, it will be critical to deploy core solutions that can meet the demands generated by increased mobile multimedia services and a growing subscriber base, including increased network capacity requirements, thousands of call transactions per second, and significant throughput.
2G/3G to 4G migrations—As mobile operators migrate their networks to LTE, they will look to minimize cost and maximize subscriber usage. This will require core solutions that can address 2G/3G network requirements, while at the same time be utilized for 4G network introductions. Operators will want to avoid a ―forklift‖ upgrade, while deploying ―best-of-breed‖ solutions based on open standards. Additionally, mobile users will expect a uniform service experience across both networks, with consideration to the bandwidth differences. According to the UMTS Forum, there is consensus in the industry that the first commercial launch of an LTE network and initial availability is expected to begin in 2010, with associated revenue to occur the following year.1 While it is likely the evolution to 4G technologies will take many years, it is imperative for mobile operators to identify multimedia core elements now that will most effectively migrate them to a 4G network in the future.
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Solutions designed for the specific requirements of the next generation multimedia core network include the ability to support both 2G/3G and 4G functionality in a single platform and provide major benefits to mobile operators that want to smoothly migrate their networks, maximize their investments, and offer an exceptional experience to their customers.
As mobile operators evolve to LTE They will benefit from solutions that can
integrate
2G/3G
and
4G
functions in a single node, providing separate access through a common multimedia core.
6.4 Standard Interfaces and Protocols EPC also supports standard interfaces and open protocols aimed at enabling operators to launch services and applications with Internet speed, while also reducing the overall cost-per-packet through the inherent advantages of going all-IP. Standardized interfaces and protocols also enable operators to achieve a ―best-of-breed‖ approach with their network infrastructure. By eliminating proprietary protocols, operators can operate an open network that empowers them to select the vendors they deem most qualified to deliver a specific network function without having to worry about interoperability issues.
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6.5 Converged Mobility and Policy Management In 2G/3G networks, diverse schemes were used for mobility management within and across the access technology boundary. So, an operator choosing to deploy 2G access technology of one kind and 3G access technology of a different kind had to deploy two divergent mobility management schemes in the same network. This caused serious issues, and more importantly impeded rapid deployment of some access technologies. EPC is an attempt toward addressing this divergent mobility management issue. With a single comprehensive architecture, EPC supports all access technologies, i.e. 2G/3G and 4G from all standards defining organizations. The basis of this convergence is the use of an IETF defined mobility management protocol such as Proxy Mobile IPv6 (PMIPv6). If an operator wants to deploy any access technology with an EPC, a single mobility management protocol, such as PMIPv6 is all they need. This is a significant step toward building a single common IP core for future access technologies with seamless mobility. This gives operators the freedom to choose any access technology without having to worry about a complete overhaul of their existing IP core or an IP core overlay.
6.6 Common Core Platform EPC highlights the growing importance of a common packet core across multiple access technologies. As many operators transition from disparate 3G specifications (UMTS and CDMA2000) to LTE and EPC, there is the potential for significant network simplification and cost savings, while also introducing greater efficiencies within the core network.
6.7 Integrating EPC Network Functions The EPC specifications call out the Mobility Management Entity (MME), Serving Gateway (SGW), and Packet Data Network Gateway (PGW) as specific network functions, but do not define them as separate nodes in the network. In keeping with the simpler and flatter architecture intentions, these three functions can logically be integrated into one node. However, this will require a solution that is capable of this integration and can deliver the benefits of such integration. 42
Support for multiple network technologies and the corresponding multimedia core network functionality in a multi-access, multi-service environment.
For instance, the MME, SGW, and PGW can be combined into one carrier-class platform. By collapsing these functions, operators could reduce the signaling overhead, distribute session management, and leverage the control and user plane capabilities of the carrier-class node. Alternatively, an operator could deploy the MME separate from the combined SGW and PGW, resulting in reduced signaling overhead (S5 and S8 would be internal), fewer hops on the bearer path, less backhaul, reduced signaling on the S7 interface, and lower session requirement for the PGW. This also provides for a single location for policy enforcement and charging data generation. Additionally, co-location of 2G/3G SGSNs with the MME will reduce signaling and context transfer overhead significantly. This co-location will also be key to 2G/3G and 4G mobility and session management. The advantage of integrating or collapsing functional elements into one carrier-class node is paramount to the goals of simplifying and flattening the network while also reducing latency.
6.8 Convergence of 3G and 4G Core Networks The concept of collapsing EPC functions can be taken a step further. The move to LTE will be an evolution, meaning many 3G, 2.5G, even 2G networks—whether 3GPP or 3GPP2—will remain 43
operational for many years to come. Mobile operators can seize this opportunity to combine EPC functions with GPRS and UMTS functions (3GPP GGSN and SGSN), easing network migration, reducing signaling overhead, enhancing resource utilization by sharing common session data storage, and improving mobility between 2G/3G and 4G access systems. Most importantly, operators have the potential to achieve this without a ―forklift‖ upgrade by leveraging their existing 3G deployed base. This results in dramatic capital and operational savings and reduces risk involved in adding a new, unproven access technology.
6.9 Easing The Migration Innovative solutions currently deployed around the globe already meet many of the requirements of LTE and EPC, such as integrated intelligence, simplified network architecture, high bandwidth performance capabilities, and enhanced mobility. Some are capable of supporting 2G/3G today on a single platform, and through software upgrades can support 4G functionality when LTE networks are deployed. Mobile operators will benefit from solutions that can provide 2G/3G functionality now and evolve to 4G functionality later without ―ripping and replacing‖ costly systems and equipment that will still be needed to support legacy networks while subscribers transition to the new network.
6.10 Integration of Multiple Core Functions Whether existing systems are deployed as SGSN, GGSN, PDSN, Home Agent, or other gateway functions, they must be designed to be integrated with or upgraded to the 4G functional elements—MME, SGW, PGW, and ePDG— through a simple software upgrade.
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6.11 Intelligence in the Network Key to creating and delivering high bandwidth multimedia services in 2G/3G and 4G networks— and meeting subscriber demand—is the ability to recognize different traffic flows, which allows functional elements to shape and manage bandwidth, while interacting with applications to a very fine degree and delivering the quality of service required. This is done through session intelligence that utilizes deep packet inspection technology, service steering, and intelligent traffic control to dynamically monitor and control sessions on a per-subscriber/per-flow basis. The interaction with and understanding of key elements within the multimedia call—devices, applications, transport mechanisms and policies—require:
Intelligent QoS control based on service type, user profile, and business policy
Visibility of the access technology type in the EPC nodes. For example, automatically adapting QoS for ongoing sessions when the user equipment performs a handover between an LTE and 2G/3G/WiMAX network
Providing a greater degree of information granularity and flexibility for billing, network planning, and usage trend analysis
Sharing information with external application servers that perform value-added processing
Exploiting user-specific attributes to launch unique applications on a per-subscriber basis
Extending mobility management information to non-mobility aware applications
Enabling policy, charging, and QoS features
6.12 PC Network Functions EPC defines a series of new network functions that flattens the architecture by reducing the number of nodes in the network, which promises to reduce capital and operational expenditures; thereby reducing the overall cost per megabyte of traffic running over the EPC, while improving network performance.
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Mobility Management Entity (MME)—The MME resides in the control plane and manages states (attach, detach, idle, RAN mobility), authentication, paging, mobility with 3GPP 2G/3G nodes (SGSN), roaming, and other bearer management functions.
Serving Gateway (SGW)—The SGW sits in the user plane where it forwards and routes packets to and from the eNodeB and Packet Data Network Gateway (PGW). The SGW also serves as the local mobility anchor for inter-eNodeB handover and roaming between two 3GPP systems.
Packet Data Network Gateway (PGW)—The PGW (sometimes called the PDN Gateway) acts as the interface between the LTE network and Packet Data Networks (PDNs), such as the Internet or SIP-based IMS networks (fixed and mobile). The PGW is the mobility anchor point for intra-3GPP access system mobility and for mobility between 3GPP access systems and non-3GPP access systems. The function is responsible for IP address allocation, charging, deep packet inspection, lawful intercept, policy enforcement, and other services.
Evolved Packet Data Gateway (ePDG)—Thee PDG is the primary element responsible for interworking between the EPC and untrusted non-3GPP networks, such as a wireless LAN. The ePDG uses Proxy Mobile IPv6 (PMIPv6) to interact with the PGW when the UE is in an untrusted non-3GPP system. The ePDG is involved in the Policy and Charging Enforcement Function (PCEF), meaning it manages Quality of Service (QoS), flow-based charging data generation, gating, deep packet inspection, and other functions.
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CHAPTER SEVEN
4G Wireless Networks: Opportunities and Challenges
7.1 Introduction The existence of 4G Networks in today’s technology-driven society is important indicators of advancement and change. 4G, or Fourth Generation networks, are designed to facilitate improved wireless capabilities, network speeds, and visual technologies. It is anticipated that as these networks continue to thrive, the demand for advanced related technologies will also grow, thereby creating new alternatives for savvy technology users to exceed their desired expectations. The following discussion will evaluate the current state of 3G Networks and will examine the future potential of these networks in expanding technology-based capabilities for consumers and industries alike. In this paper we present an overall vision of the 4G networks starting by presenting some of the key features they will provide, and then discussing key challenges the researchers and vendors are attempting to resolve, and finally briefly describing some of the proposed solutions to these problems.
7.2 Background Within the cable television industry, the expansion to 4G Networks is a very real possibility in 2009. Recently, Comcast and T-Mobile have collaborated and agreed to the development of a ―mobile 4G network‖ to be tested in Washington D.C. and Baltimore, MD. However, this process is lengthy, and the rollout of such a network is not expected for close to two years, as the network requires extensive and detailed testing in order to ensure that there are no ―bugs‖ that could interrupt the flow of mobile traffic across the network. This type of opportunity is of critical importance in developing a network that is capable of advancing technology to never47
before-seen heights. Similarly, AT&T, one of the world’s largest telecommunications providers, will begin its own rollout of a 4G Network in 2011, enabling its vast user base to explore new downloading speeds and capabilities. The utilization of LTE mobile broadband technology is an opportunity for the corporation to expand its horizons into 4G territory, upstaging current 3G capabilities.
In the process of expanding into the new 4G enterprise, AT&T will seek to
overcome any limitations brought on by the 3G Network process. As AT&T begins its rollout process, there are many considerations involved in ensuring that the transition is a success, and that existing networks are not interrupted in the process of developing the 4G platform. In addition, mobile providers such as AT&T will likely develop new pricing strategies from some of their most popular products, including the iPhone, in response to the challenges of developing faster networks. The 4G Network process requires a unique approach to developing effective models for strategic purposes. The necessity for 4G networks is associated with the increased utilization of data websites such as You Tube and Facebook, which require tremendous bandwidth in order to be used successfully. Because these websites are becoming increasingly popular amongst the general public, it is more important than ever for telecommunications providers to develop opportunities to accommodate the needs of the consumer population. Consumers have come to depend on different sources of data as a source of entertainment and for convenience. Therefore, it is important that organizations such as Verizon and AT&T continue to identify areas where technological improvements are required. In January 2009, the first operating 4G Network was established by a joint venture between Clear wire and Intel, which reflected an opportunity for residents and businesses in Portland, Oregon to ―connect wirelessly anywhere in Portland at true broadband speeds‖.
However, with the technology quickly
approaching a widespread rollout, many cities, states, and countries will soon possess similar capabilities, as consumers and businesses alike will be provided with different opportunities to expand their networks and interfaces with advanced capabilities. Furthermore, it is evident that the Clear wire strategy is not without its disadvantages, and additional efforts must be made to overcome any technology-related problems that might persist before a widespread rollout is even considered.
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7.3 Opportunities In general, it is believed that the existence of the 4G network is designed to facilitate the development of a superior alternative to the existing 3G strategy in terms of quality and data transmission speed. For developers of 4G Networks, there is a great dependence upon advanced technologies and increased speed in order for the network to be a success. It is known that in terms of the 4G Network, ―it requires substantial improvements to multimedia messaging services, including video services, in order to approve a new generation. It wants a data speed transfer rate of at least 100 megabits per second while a user is physically moving at high speeds and a one gigabit per second data rate in a fixed position‖.
From this perspective, it is
important for the new data network to meet the expected demand of the consumer and of different industries, which have come to depend upon high-speed data networks with minimal interruptions for a variety of needs. A. Cost and Affordability In terms of 4G Network cost and affordability, there are a number of issues to consider that reflect some degree of risk, as well as opportunity, so that these networks are successful once rolled out to the general public, and in general, 4G Networks are designed in order to create an environment that supports high-speed data transmission and increased profit margins for organizations that utilize these capabilities. Developing a successful 4G Network platform is a positive step towards the creation of a wireless and broadband environment that possesses rapid transmission speeds, data integrity modules, and other related events that encourage users to take additional risks in promoting successful utilization of these 4G tools. B. Capabilities and Features Although the 4G Network platform is not brand new, many telecommunications providers have not yet developed their own alternatives that will support this network in full. Therefore, 4G-related products are still in the development phase, with additional products to be developed and rolled out on a periodic basis. With the creation of these alternatives, it is likely that 4G Networks will continue to expand their scope and promote their own brand of personalization for consumers that seek these types of alternatives. In general, the possibilities associated with 4G Networks are endless, as high-speed data transmission and associated capabilities are more feasible than ever. This supports the notion that the demand for more complex networks and related capabilities are stronger than ever, as a greater number of consumers continue to buy into the potential that exists with 49
advanced networks, such as 4G. With the appropriate combination of resources, it is possible for 4G Networks to create alternatives that exceed consumer and industry expectations. Therefore, 4G developers must consider the appropriate security measures, the promotion of high-speed data transmission across the network, and must also consider the ways in which data quality and integrity might be preserved in order to provide the most satisfactory results. This 4G is intended to replace the current 3G systems within few years. The ambitious goal of 4G is to allow everyone to access the Internet anytime and everywhere. The provided connection to Internet will allow users to access all type of services including text, databases, and multimedia. 4G, unlike 3G, is IP based, that is every user connected to the Internet will have an IP address. This feature makes it easier to integrate the infrastructure of all current networks and consequently will it easier for users to access services and applications regardless of the environment. 4G will also provide higher bandwidth, data rate, lower authentication overhead, and will ensure the service is constantly provided to the user without any disruption. Another key feature of 4G networks is high level of user-level customization. That is, each user can choose the preferred level of quality of service, radio environment, etc. Accessing 4G networks will be possible virtually by using any wireless device such as PDAs, cell phones, and laptops.
Figure 7.1: 4G will allow everyone to access the Internet from everywhere using almost any wireless device.
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7.4 New Challenges 7.4.1 Security and Privacy In the development of 4G Networks, security measures must be established that enable data transmission to be as safe as possible. Specifically, ―The 4G core addresses mobility, security, and QoS through reuse of existing mechanisms while still trying to work on some mobility and handover issues‖ [3]. Therefore, it is necessary for the organization to develop an effective series of tools that support maximum 4G security measures as a means of protecting data that is transmitted across the network from hackers and other security violations. Because of the nature of the 4G network, there is an increased likelihood of security attacks, and therefore, multiple levels of security, including increased requirements for authentication, will be necessary to protect data and information that is transmitted across the network . One of the main goals of G4 networks is to blanket very wide geographic area with seamless service. Obviously, smaller local area networks will run different operating systems. The heterogeneity of these wireless networks exchanging different types of data complicates the security and privacy issues. Furthermore, the encryption and decryption methods being used for 3G networks are not appropriate for 4G networks as new devices and services are introduced for the first time in 4G networks. To overcome these security and privacy issues, two approaches can be followed. The first is to modify the existing security and privacy methods so that they will be applicable to heterogeneous 4G networks. Another approach is to develop new dynamic reconfigurable, adaptive, and lightweight mechanisms whenever the currently utilized methods cannot be adapted to 4G networks.
7.4.2 Quality of Service With respect to network quality, many telecommunications providers are promising that there will be enhanced connectivity, and the quality of data that is transmitted across the network will be of the highest possible quality, as in the case of Ericsson’s 4G Network for TeliaSonera. The company promises that ―The new 4G network will do for broadband what mobile telephony did 51
for voice. With real-time performance, and about 10 times higher data rates compared to today's mobile broadband networks, consumers can always be connected, even on the move‖. As a result, it is important for providers to develop an effective approach to the 4G Network that will enhance quality, provide effective security measures, and will ensure that all users are provided with extensive alternatives for downloading video, music, and picture files without delays. The main challenge that 4G networks are facing is integrating non-IP-based and IP-based devices. It is known that devices that are not IP address based are generally used for services such as VoIP. On the other hand, devices that are IP address based are used for data delivery. 4G networks will serve both types of devices. Consequently, integrating the mechanisms of providing services to both non-IP-based as well as IP-based devices is one of key challenges 4G networks have to address.
7.5 Complex Architecture 8.5.1 Multimode End-User Terminals To reduce operating costs, devices that operate on 4G networks should have the capability to operate in different networks. This will not only reduce the operating cost but will also simplify design problems and will reduce power consumption. However, accessing different mobile and wireless networks simultaneously is one of the major issues 4G networks have been addressing. One mechanism that has been proposed to handle this problem is termed ―multi-mode devices‖. This mechanism can be achieved through a software radio that allows the end-user device to adapt itself to various wireless interfaces of the networks.
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Figure 7.2: Accessing multiple networks and services through multi-mode software
7.5.2 System Discovery and Selection Due to the heterogeneity of 4G networks, wireless devices have to process signals sent from different systems, discover available services, and connect to appropriate service providers. Various service providers have their own protocols which can be incompatible with each other as well as with the user’s device. This issue may complicate the process of selecting the most appropriate technology based on the time, place and service provided, and thus, may affect the Quality of service provided to the end user. One solution to resolve this issue is called ―Systeminitiated discoveries‖. This mechanism allows automatic download of software modules based on the wireless system the user is connected to. Another approach to handle this problem is based overlay networks. In such case, the end-user device is connected to different networks through an 53
overlay network. The overlay network performs all necessary tasks such as protocol translation and Quality of service negotiation as depicted in Figure 3.
7.5.3 Service and Billing Managing user accounts and billing them has become much more complicated with 4G networks. This is mainly due to heterogeneity of 4G networks and the frequent interaction of service providers. The research community addressed this concern and proposed several frameworks to handle the customers’ billing and user account information.
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CHAPTER EIGHT
Conclusion
4G wireless networks not only enable more efficient, scalable, and reliable wireless services but also provides wider variety of services. These opportunities come with a need for rethinking our security, privacy, architect and billing technologies have been used for previous generations. We believe, however, that future research will overcome these challenges and integrate newly developed services to 4G networks making them available to everyone, anytime and everywhere. LTE-Advanced, the backward-compatible enhancement of LTE Release 8, will be fully specified in 3GPP Release 10.It has already been submitted as 3GPP’s 4G candidate radio interface technology to ITU-R. We have described its main technologies: carrier aggregation, enhanced MIMO, cooperative multipoint transmission and reception, and relays. For each one, we have examined their benefits, challenges, and some existing approaches to tackle these challenges. However, several issues in each of them are still open and require further research. It is the combination of these technologies, and not just a single one, that will enable achieving the target performance requirements established by IMT-Advanced. The development and integration of these elements will not end with 3GPP Release 10, but will provide the starting pointfortheirimplementation.Inadditiontotheelementsthatwehaveexaminedin.This paper, it is also expected that the use of femtocells, self-organizing networks, and energy management systems will drive the evolution of current and future mobile wireless networks.
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References [1] ITU-R,Circularletter5/LCCE/2,Tech.Rep.,March2008. [2] ITU-R, Acknowledgment of candidate submission from 3GPP Proponent under step 3 of the IMT-Advanced process (3GPP Technology), Tech. Rep, October. [3] ITU-R, Acknowledgment of candidate submission from IEEE under step3oftheIMTAdvancedprocess (IEEE technology), Tech. Rep., October. [4] ITU-R, Acknowledgment of candidate submission from China (People’s Republic of) under step 3 of the IMT-Advanced process (3GPP technology), Tech. Rep., October. [5] ITU-R, Requirements related to technical performance for IMT-Advanced radio interface(s), Report M.2134, 2008. [6] 3GPP, TR36.913RequirementsforfurtheradvancementsforEvolved Universal Terrestrial Radio Access (E-UTRA)(LTE-Advanced),Tech. Rep., December2009[Online]. Available: http://ftp.3gpp.org/specs/html-info/36913.htm . [7] 3GPP, Overview of 3GPP release8v.0.1.1, Tech. Rep., June2010. [8] 3GPP, TS36.323 Packet Data Convergence Protocol (PDCP) specification, Tech.Rep. December2009[Online]. Available: http://www.3gpp.org/ftp/Specs/html-info/36323.htm . [9] 3GPP, TS 36.322 Radio Link Control (RLC) protocol specification, Tech. Rep., March 2010 [Online]. Available: http://www.3gpp.org/ftp/Specs/html-info/36322.htm . [10] 3GPP, TS36.321 Medium Access Control (MAC) protocol specification, Tech. Rep., March2010 [Online]. Available: http://www.3gpp.org/ftp/Specs/html-info/36321.htm
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