Session M2E
Work in Progress - Real-Time Remote InternetBased Communication Laboratory Arsen Melkonyan, David Akopian, and C. L. Philip Chen University of Texas at San Antonio,
[email protected],
[email protected],
[email protected] Abstract - Over the past decade, with the continued development of information technology the Internet has become a tremendously important part in modern education. Today's graduating electrical engineers need marketable skills which are typically developed in the classroom by experimenting for hands-on experience. Because of overloaded work days and restrictive laboratory hours students generally cannot physically attend labs. Therefore Internet based virtual laboratories can be viable alternatives to the traditional hands-on laboratories. Virtual laboratories have been successfully used by several universities for a few years now. This article describes an on-going program at the University of Texas at San Antonio (UTSA), where remote desktop technologies were used for the hardware based communication laboratory creation. Index Terms – Client, Remote desktop, Server, Virtual laboratory and Distance learning. INTRODUCTION The academic field is undergoing significant changes correspondent to the revolutionary advances in technology. Nowadays, more and more students have full time jobs or family obligations, which negatively affect on the frequency of student visits to the classes or labs. One of the enormous opportunities modern technologies provide lies in the effective use of computers and the Internet as potent educational tools. In the last few years many universities have successfully used Internet based distance learning technologies [1]-[4]. This article discusses the possibility of replacing traditional hands-on laboratories with virtual laboratories followed by a discussion of remote desktop applications in distance learning educational communication systems. The rest of the article has been further organized as follows. A brief review of several remote desktop technologies has been done in section 2. Section 3 presents the analysis of hardware based communication systems available in the market. Section 4 explains the overall remote Internet-based laboratory. Experimental results have been shown in Section 5 and the article is concluded in Section 6. REMOTE DESKTOP TECHNOLOGIES With the continued expansion of The Internet and Web technologies Remote Desktop (RD) became a widely used tool in modern academic work. Instructors explain class
topics and help students on specifically equipped computers which are accessed remotely. Nowadays it is widely used in distance learning classes [5]-[9]. Early RD technologies were designed for remote computer management, which involved command line interfaces and access through web pages without seeing the same desktop view as a local user. Along with the system development the networked computers' capabilities increased and it became feasible to use Graphical User Interfaces (GUI) in remote desktop technologies. In the beginning Microsoft Corporation introduced remote desktop access only for their servers in Windows NT 4.0 Terminal Server Edition. Terminal Server was then refined in the Windows 2000 Server Series. Finally, Remote Desktop was expanded in Windows XP for Remote Assistance where a user can invite any other user to assume complete control over his/her system through Internet [10]. The RD system from Microsoft is available on all machines with Windows XP and newer Windows versions, and is also available in Microsoft web page for free download. It is compatible only with Microsoft Windows operation systems. Besides Windows RD there are many RD systems present in the market with different capabilities. The Table 1 shows the general descriptions of some of them. • TeamVeiwer [11]: It provides the client instant control of the computer or server desktop over Internet. It is available either for Microsoft or Mac platforms. Furthermore it fully supports the connectivity between different platforms. It includes full encryption based on the https/SSL standard for enhanced security. TeamViewer has the capability to define the level of user access to the computer. It is usually installed software on the server side. Clients are able to connect to the server from any computer running the software without permanent installation. Other attractive TeamViewer’s features are file transfer, chat, the ability to define access levels and multi-user screen view. One of the bottlenecks of the software is the multi-user access scheduling. The system gives complete access to the client, i.e. all the clients can have complete control of the mouse and keyboard at the same time, which makes the system partially unsuitable for multi-user use. TimeViwer software is currently available in the market for free, but only for private use. As of today it costs $699 for lifetime commercial use [11].
978-1-4244-4714-5/09/$25.00 ©2009 IEEE October 18 - 21, 2009, San Antonio, TX 39th ASEE/IEEE Frontiers in Education Conference M2E-1
Session M2E TABLE 1 REMOTE DESKTOP SYSTEMS Compatibility Security Software Level Installation for Client
File Transfer
Chat
Remote Desktop Connection
Yes
No
Win/Mac (Viewer only)/ Linux (Viewer only)
High
TeamViewer
Yes
Yes
Win/Mac
GoToMyPc
Yes
Yes
LogMeIn Free
No
LogMeIn Pro
Yes
Products
Multi-User Support
Response Delay
Prices
Yes
No
Medium
Free
High
No
Partially Yes
Medium
Medium
Win/Mac/Linux/Unix
High
Yes
No
High
High
No
Win/Mac
High
No
No
High
Free
Yes
Win/Mac
High
No
No
High
High
• GoToMyPc [12]: This application was developed by Citrix Corporation. It provides a connection between client and server by using the Internet through the intermediate GoToMyPc server, which causes additional delays during client-server connection. GoToMyPc software needs to be installed on the server side. The client once installs a small program on his computer, and connects to the server by visiting the webpage and entering a previously specified username and password using any web browser. It is available for Windows, Mac, Unix and Linux. GoToMyPc secures communicated data using Advanced Encryption Standard (AES) encryption. It gives the client either full access to the server or screen view ability. Guests are given determined levels of access by invitation emails sent from remote desktop session organizer. GoToMyPc has file transfer, chat, remote sound, files printing and drawing abilities. However the lack of multi-user ability and the software installation on the client side is a bottleneck for academic use. As of today GoToMyPc costs $179/year [12]. • LogMeIn [13]: This free RD software connects the client to the server directly through the Internet. LogMeIn software needs to be properly installed on the server. The client directly connects to the server by visiting the LogMeIn webpage and entering a previously specified username and password using any web browser. LogMeIn is compatible with Windows or Mac platforms and uses a high level SSL end-to-end 128 to 256-bit encryption. LogMeIn gives the client full access to the server. “LogMeIn Free” software has chat, remote control and desktop viewing abilities. “LogMeIn Pro” version has additional capabilities of remote sound, file transfer, drag and drop files, sharing and the capability to organize meetings where the guests, invited to the meeting by receiving a special link from the meeting organizer, can obtain complete access over the server or just screen view abilities. As of today LogMeIn Pro has a monthly charge of $19.75 [13].
EDUCATIONAL COMMUNICATION SYSTEMS The role of laboratories in modern technical classes is critical and should not be underestimated. It is here students learn how to apply the concepts studied in the class on actual hardware. Over the last decade, the area of wireless communications has become a global technology with the recent arrival of such popular systems as 3G cellular, wireless local area networks and wireless sensor networks. As such, today's graduating electrical engineers need marketable hands-on skills to compete for attractive jobs in this industry. Several vendors of learning systems offer hardware based training modules. Table 2 provides a comparative analysis of several systems currently available in the market. They are reviewed next. I. TIMS Systems from EMONA Instruments [14] EMONA Instruments offers several hardware based educational communication systems under TIMS (Telecommunication Instructional Modeling System) logo. These are trainers which are needed to complete a set of communications laboratory experiments. • The TIMS-301/C System Unit [14]: The basic TIMS301/C system comprises the hardware components and documentation for a TIMS laboratory training system. TIMS-301/C hardware includes two components: the TIMS-301/C system unit with its fixed modules in the bottom part of unit and 12-slot top part for plug-in modules, and the necessary plug-in modules, which includes a broad range of single function building blocks. The fixed modules includes master oscillators, buffer amplifiers, frequency and event counter, voltage output, oscilloscope display selector, headphone amplifier and power supply. EMONA TIMS also offers a wide range of plug-in modules for different experiments. The basic plug-in modules (adder, multiplier, phase shifter, quadrature phase splitter, voltage controller, pseudorandom sequence generator and low pass filter), in association with fixed modules allows the students to perform a wide range of communication experiments [14].
978-1-4244-4714-5/09/$25.00 ©2009 IEEE October 18 - 21, 2009, San Antonio, TX 39th ASEE/IEEE Frontiers in Education Conference M2E-2
Session M2E Products
TABLE 2 EDUCATIONAL COMMUNICATION SYSTEMS Software Control Experiments Multi-Experiments Level
Online Control
Prices
EMONA TIMS-301/C System Unit
Yes
Basic
Yes
No
High
EMONA net*TIMS
Yes
Basic
Yes
Yes
Expensive
NI ELVIS/EMONA DATEx bundle
Yes
Basic
Yes
No
Medium
NI RF/Communications Lab bundle
Yes
Advanced
Yes
After some modifications
Expensive
NIDA 130E Training Console/ Experiment Card Set bundle
Yes
Advanced
Yes
No
High
• EMONA Telecoms-Trainer (ETT) 202 [14]: Also known as DATEx it is designed as an additional unit for National Instruments’ (NI) ELVIS trainer. ETT-202 is a trainer board, which plugs into the NI ELVIS platform and can operate in local mode under NI LabView software. ELVIS/DATEx telecommunications bundle is shown in Figure 1(a). The board management and waveform displays and measurements are performed and presented using LabView and its interface. User management of the ETT-202 board occurs in two different ways. The first is the manual control method; during which student can control the board manually using the knobs and the controllers on it, and the second method is PC-based control: the full board can be controlled using DATEx SFPs software. DATEx SFPs uses the LabView application, which displays the ETT/202 board on the computer display with exact knobs and controllers. The EMONA DATEx SFPs, shown in Figure 1(b), gives the students freedom to build communications systems in hardware by joining together circuit blocks using cables similar to block diagrams studied during the class. DATEx includes more than 20 circuit blocks for basic communications operations such as adder, multiplier, mixer, signal generator and phase shifters, which can be effectively used in the construction of block diagrams by patching together them according to theoretical telecommunications block diagrams by using wires and NI ELVIS to supply the stimulus and measure the response [14]. • EMONA net*TIMS [14]: It offers TIMS hardware based experiments delivered simultaneously to multiple students across LAN & the Internet. By using the net*TIMS the instructor can set-up telecommunications experiments in the laboratory, which students can easily access and manipulate remotely. The net*TIMS-enabled modules have knobs, controllers, switches and potentiometers which can be remotely controlled via Ethernet. The net*TIMS-enabled modules are simply plugged into a standard TIMS-301 System Unit and connected to the net*TIMS server, which is linked up to the LAN/Internet via an Ethernet port. The GUI at the user computer reproduces the experiment front panels and shows acquired real signals. The students are able to log on to the net*TIMS server using a web browser after which
they receive a JAVA-based client screen relative to the specific experiment set up on the net*TIMS System. The net*TIMS server has multi-user environment functionality, which allows several students, each at a different location, to log onto the same net*TIMS Server and independently complete individual sessions of the same experiment [14]. While net*TIMS trainer has an advantage of providing simultaneous multiple user access, the cost of net*TIMS trainer (more than $30K) is the main constraining factor for the wide deployment. Also the number of experiments is limited and cannot be controlled by the user. RD-based approach may not provide simultaneous multiple user access but it is more flexible in connecting to different trainers and thus providing wider access with controlled deployment costs. EMONA also offers various software simulators [14].
(a) (a)
(b)
FIGURE 1 The ELVIS/DATEx telecommunications bundle, (b) Emona DATEx SFP.
II. Systems from National Instruments [15] National Instruments offers many high-performance platforms for hands-on learning [15]. • The NI RF/Communications Lab Bundle (PXI Platform) [15]: This product offers students the capability to use LabView graphical programming and PXI-based hardware to communicate and receive live RF and communications signals. The NI RF/Communications Lab Bundle (PXI Platform) includes hardware and software to build a computer-based platform with a frontloading compact PCI form factor. The bundle includes an eight-slot PXI chassis with an RF signal generator, an RF
978-1-4244-4714-5/09/$25.00 ©2009 IEEE October 18 - 21, 2009, San Antonio, TX 39th ASEE/IEEE Frontiers in Education Conference M2E-3
Session M2E signal analyzer, and a high-performance, embedded PC controller. The RF signal generator and RF signal analyzer form a transmitter/receiver pair for communications signals from DC to 2.7 GHz with up to 20 MHz of real-time bandwidth. Both the RF signal generator and RF signal analyzer are programmable with graphical applications built in NI LabView software. The embedded PC controller provides a connection between computer and hardware [15]. All the NI hardware modules are controlled by LabView software. The LabView applications can be “published” on a web by using the web publisher tool in NI LabView. After publication the LabView application becomes a regular web page, which can be freely accessed by students anywhere. The first student to access the web page will have complete control over the application. The other students will be able to merely view the web page; they will not be able to manipulate the program until the first student completes his session and closes his web page. Control is granted to the other students in order of access. III. Systems from NIDA [16]
EMONA net*TIMS is hardware based, fully operated communication trainer offered by EMONA TIMS, and is an excellent virtual laboratory. The high price of the system however is prohibitive for many universities. The ELVIS/DATEx telecommunications bundle is a complete hardware based trainer, which provides a wide range of practical communication experiments and is about four times cheaper than the EMONA net*TIMS system. It was chosen as an affordable alternative to EMONA net*TIMS. As discussed in the previous section ELVIS/DATEx telecommunications bundle can be easily controlled by EMONA DATEx SFPs software, which is a LabView application. It should be possible to publish DATEx SFPs as a web page by using the web publisher tool from NI LabView, but the tool is removed from DATEx SFPs. Remote Desktop technologies were chosen as a solution. Using Remote Desktop (RD) technologies the students can directly access the DATEx SFPs and ELVIS/DATEx telecommunications bundle experiments by accessing the server which connected to the bundle and controls its operation. As a case study the TeamViewerer is used as RD software.
NIDA Corporation offers electronic training and computer assisted instruction hardware and software modules [16]. NIDA provides learning modules for communication systems as a combination of the NIDA Model 130E Trainer Console and communication experiment cards. • The NIDA Model 130E Trainer Console [16]: This trainer console functions as the platform for electronic experiments with Computer Assisted Instruction (CAI) support. The 130E serves a power supply for NIDA 130 Series experiment cards. Discrete voltages are used to activate the experiment cards, which allow students to work with operational electronic circuits using typical laboratory test equipment [16]. • The RF Communications Experiment Card Set [16]: This set is designed to cover the theory of operation, troubleshooting, and repair of standard AM/FM broadcast band receivers and AM/SSB/NBFM communications transceivers. The RF Communications Experiment card set allows students to study a wide range of selected topics in communication such as basic system composition, the RF spectrum, atmospheric effects on radio waves, modulation techniques, AF/RF and RF/AF conversions, phase-locked loop and manual tuning operations, AGC, crystal and voltage controlled oscillators and antenna theory [16].
(a)
REMOTE INTERNET-BASED LABORATORY Hands-on laboratories provide valuable experience in engineering and technology education. However, such trainers are not always necessarily available to students. Virtual laboratories are a possible alternative to traditional laboratories, and they are already used in distance learning education in several universities.
(b) (a)
FIGURE 2 Snapshot of the laboratory, (b) block diagram of the system.
978-1-4244-4714-5/09/$25.00 ©2009 IEEE October 18 - 21, 2009, San Antonio, TX 39th ASEE/IEEE Frontiers in Education Conference M2E-4
Session M2E
FIGURE3 Questions related to distance learning systems
The TeamViewerer software gives the client access to all programs on the server. The Windows XP professional edition is used as the operation system on the server. The security policy tool from Windows is used to control access to the operating system and the programs, such as DATEx SFPs. All the experiments can be done remotely through Internet. It also can provide connectivity between students and instructor during the online experiments by using the TeamViewer’s software chat functionality. The snapshot and the block diagram of the system are shown in Figure 2. RESULTS The survey about distance learning systems in education has been conducted in classroom setting before using the remote Internet-based laboratory. The responses from the students have been collected and analyzed. The poll results are graphically shown in Figure 3. All students use the Internet regularly (100%) and most of them (92.3%) have access to it at home. Less than the half of the class (38.5%) used distance learning systems in their education before, but most of the class (84.6%) would like to use it in future education. The remote Internet-based laboratory sessions are offered in Wireless Communication class which is a catalog Electrical and Computer Engineering department’s course at the University of Texas at San Antonio. The Wireless Communication course covers aspects of wireless communication systems at the physical layer, such as propagation modeling for wireless systems, modulation schemes used for wireless channels, diversity techniques, antenna systems and access schemes. It also reviews the modulation theory, spectral analysis and fundamentals of digital communications. The Amplitude Modulation (AM) lab was presented during the class and the reviews from the students were collected before using the system. The AM experiment was successfully completed by the student as homework by using the remote Internet-based laboratory. The AM experiment allows the students to generate signals in hardware, perform modulation by following well defined experiment steps, which are described in the experiment tutorial. Students had full access to the virtual lab 24 hours a day during one week. Another review has been collected from the students after
completing the AM experiment. The results from the reviews are shown in Figures 4 and 5. As shown in Figure 4 (a), the responses from the student before using the system were mostly positive, but a large percentage of the students (88.5%) were unsure about the connectivity of the system. The majority (84.6 %) expected that the virtual lab would be related to class topics. A slight majority of students (55.4%) were not sure neither the virtual lab would contribute positively to their education or increase their motivation (73.1%), but most of them graded the usability and the virtual lab idea as excellent or good respectively 28.5% and 63.8% shown in Figure 5 (a). After using the remote Internet-based laboratory all the students (100%) were confident that the lab was related to class topics. The majority of the class (73.9%) concluded that it helped them to better understand the topics discussed in the class. Also majority consensus was that the virtual lab helped the students to get applied knowledge (68.4%), and that it improved the motivation of students (68.4%). The large percentage of the students (73.9%) also expected after using the system to have more virtual lab experiments in their future education. Most of the students (89.6%) graded the connectivity to the virtual lab as easy. Finally, the preexperiment poll figures were almost equivalent to the post assessment poll figures on the question of the usability of the system. The overall virtual lab is assessed as “excellent” by 21.1% of students and “good” by 68.4% of users. The results of the polls are shown in Figures 4 (b) and 5 (b). For future work, the Wireless Sensor Network classroom kit from Crossbow Technology will be used in the virtual lab. CONCLUSION In this paper a remote laboratory design concept for studies in telecommunications is studied. The available remote desktop (RD) software is reviewed. As a case study RD software Teamviewer is integrated with a telecommunication ELVIS/DATEx trainer for virtual handson experiments. The system has been used in classroom setting; the user assessment data are collected and analyzed showing a strong interest and potential in virtual hands-on experimentation. This is especially valuable for those students whose cannot physically attend lab sessions to obtain hands-on experience.
978-1-4244-4714-5/09/$25.00 ©2009 IEEE October 18 - 21, 2009, San Antonio, TX 39th ASEE/IEEE Frontiers in Education Conference M2E-5
Session M2E
(a)
(b) FIGURE 4 Questions related to Virtual Lab system. (a) Before using virtual lab, (b) after using virtual lab
(a)
(b) FIGURE 5 Questions related to Virtual Lab system. (a) Before using virtual lab, (b) after using virtual lab
Despite of the fact that the majority of the students had not used distance learning systems before, they certainly would like to use them in the future. Most of the class, after using the system, opined that it helped them to better understand syllabus topics and gain more applied knowledge.
[5].
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[11].
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[12].
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[13].
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[15].
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[16].
NIDA: http://www.nida.com
ACKNOWLEDGEMENT This work has been supported in part by the Texas Higher Education Coordinating Board and by the Interactive Technology Experience Center at the University of Texas at San Antonio. REFERENCES [1].
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