charging and pricing challenges for 3g systems

FOURTH QUARTER 2005, VOLUME 7, NO. 4 IEEE COMMUNICATIONS

SURVEYS The Electronic Magazine of Original Peer-Reviewed Survey Articles

www.comsoc.org/pubs/surveys

CHARGING AND PRICING CHALLENGES FOR 3G SYSTEMS ZOHEIR EZZIANE, DUBAI UNIVERSITY COLLEGE ABSTRACT Mobile operators and service providers require a flexible charging system/mechanism that accommodates various pricing models, such as models based on a flat rate, call duration, call volume, Quality of Service (QoS), or user perceived quality, in order to fulfill not only conventional business models but also innovative models. This article reviews current methods for pricing, charging, and billing for 3G mobile services. It further recommends that charging and billing methods be reexamined, as charging by simple metrics for wireless network and service providers will result in lost revenue. This article examines the selection of a specific pricing method, which could be based on customer and service profile characteristics. It discusses the characteristics that are exhibited in third generation (3G) type services but are non-existent in the previous services, leading to new and challenging methods to account for their usage. This article also reports that innovative approaches are needed when considering the application of accounting principles such as mediation, billing, and charging to these new services.

E

merging Internet Protocol (IP) networks, and alternative access devices (mobile phones, Personal Digital Assistants (PDAs), etc.), create significant challenges and opportunities for accounting and billing architectures within the next-generation IP services sphere [1]. In this environment the nature and range of services proliferate. While traditional telecommunication services have extended to call forwarding, voice mail, and premium call services, typically through intelligent network technology, the emerging environment sees services extending to email, VoIP (Voice over IP), media streaming, messaging, application usage, and various content-oriented access scenarios. Traditional telecommunications billing and accounting systems are proprietary to providers. Accounting and billing for information technology (IT) services are limited, while the majority of services have been delivered free over the Internet, and flat-rate access fees have been charged [2]. The widespread use of the flat-rate model has been attributed to the fact that most existing service providers emerged from the telco-based world where they have been accustomed to distance-based and time-based billing. However, in an IP world geography is irrelevant. Time-based billing further discourages the use of IP-based services [3]. The IT and telecommunications industry is currently witnessing a paradigm shift toward services that are composed of standard software components and delivered over emerging network technologies, which is the next generation of mobile

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services. An innovative change in the accounting models for these services is needed. This has paved the way for open and flexible accounting solutions that can accommodate the numerous services that will be rolled out over the lifetime of current technology waves [4]. Wireless and mobile networks have experienced exponential growth in terms of the capabilities of mobile devices, middleware development, standards and network implementation, and user acceptance [5]. According to Forrester (www.forrester.com), there were 1.5 billion mobile cellular users as of February 2005; this figure is higher than the total number of main telephone lines. In another report, the worldwide numbers were projected to rise to 1.4 billion by 2007 and to 2 billion by 2010 [6], thereby exceeding the combined total of all computing devices several fold. In addition, countries with a lack of regular telecom infrastructure are likely to embrace wireless and mobile communications to serve both urban and rural areas [7]. According to Sam et al. [6], between the fourth quarter of 1996 and the first quarter of 1999, prices declined by more than 33 percent across North America, Europe, and the Far East. According to the Cellular Telecommunications and Internet Association (CTIA) (http://www.wowcom.com/research_statistics/index.cfm), more than 600 billion wireless minutes were used in 2002, and more than 500 billion wireless minutes were used in the first half of 2004. This represents an increase of more than 35 percent year over year.

IEEE Communications Surveys & Tutorials • Fourth Quarter 2005

Moreover, in order for penetration rates to increase, prices have had to drop in order to provide incentives to consumers. The growth in the number of wireless subscribers and data use has become evident in recent years (www.wow-com.com). In addition, data applications, albeit in the primitive form of text messages, are experiencing a similar increase [8]. According to studies, one billion text messages are being exchanged in Europe alone over wireless networks (www.sims.berkeley. edu/research/projects/how-much-info-2003/telecom.htm). When wireless providers deploy higher-speed networks, the usability of wireless Internet will become much more obvious due to the use of data-rich applications. A number of capacity-demanding data applications are expected to increase wireless data traffic [9], including video telephony and videoconferencing, Internet browsing, mobile commerce, multimedia messaging, and geolocation applications. These developments add a burden on mobile operators and service providers to offer sophisticated payment services and transparent charging models. Through payment for multimedia services, mobile operators and service providers are seeking to tap into new revenue streams by being a channel to market for content providers [10]. Some providers are already offering exclusive content to their consumers. However, the Short Messaging Service (SMS) experience has shown that it is important for mobile users to be able to share and communicate across network boundaries. The i-mode experience in Japan has proved that offering both approved and non-approved sites can co-exist and earn revenue for all parties. Content providers are in a strong position since they own multimedia that consumers are willing to buy. A key factor for service providers is to make sure that consumers are serviced in a very effective and efficient manner. Telecommunication service providers explain their resistance to introducing more dynamic charging models (based on usage, value, service, application, or transaction type) by pointing to the absence of sophisticated billing and accounting systems. The proliferation of consumer QoS expectations has highlighted severe inadequacies with the service providers’ flat-rate business models. When a mobile call is dropped, is a discount not received because the provider will not give one or because the provider’s billing system does not possess the functionality to do so? For example, consider a simple comparison of the two models, whereby in the traditional model a mobile user requests the download of a video 10 MB in size, but the actual download required 12 MB due to some retransmission issues. Consequently, the provider can only charge for 10 MB and thus has lost revenue on 2 MB while also failing to provide a quality service. In a content-based model, the user is charged for the video, not the size. Generally, users require the provision of “one stop billing” for the transport, service, and content part of a service offered by network operators and application/service providers. The implementation of this requirement obliges the network operator to collect charging data from all parties and bill the users for each chargeable event accordingly [11]. Just as important as determining the value of content is the question of how content-derived revenues/charges should be settled between the various parts of the provisioning chain (network providers, content providers, service providers, etc.). Usage details must be delivered by each of the constituent entities, compiled, rated, discounted, and billed, and then the money collected from the user has to be settled among all providers in the chain. These factors, along with the inherent complexities of new 3G services, place demands on innovative IP billing and accounting systems that cannot be compared to the require-


ments of traditional flat-rate systems for first-generation (1G) services.

BILLING, CHARGING, AND ACCOUNTING FOR 3G SERVICES Billing, charging, and accounting are the most critical operational support activities conducted by a network or a service provider in the telecommunications industry. The ability to effectively and efficiently charge for the consumption of resources represents a critical competency of any telecommunications organization. This activity ensures revenue collection for services offered and is the most important consumerfocused operation support process of any organization.

TELECOMMUNICATION STANDARDS In the US and Japan, 3G often carries the name International Mobile Telephony 2000 (IMT2000). In Europe 3G has become Universal Mobile Telecommunications System (UMTS) following the European Telecommunications Standards Institute (ETSI) perspective. The European industrial players have created the 3rd Generation Partnership Project (3GPP) for the standardization of UMTS. 3G mobile networks provide the foundation for new services with high-rate data not provided by 2G systems [12]. 3GPP — The 3GPP is a collaboration agreement between a number of telecommunication standards bodies referred to as “Organizational Partners” that was established in December 1998. The goal of the partnership is to produce technical specifications for 3G mobile systems based on the evolved Global System for Mobile Telecommunications (GSM) networks and radio access technologies, which are supported by the Organizational Partners. A 3GPP group has produced a number of standards related to charging and billing, within an IP-based service domain. Furthermore, the development of advanced services led to new requirements on the part of customers, mobile operators, and service providers. Based on the 3GPP standards (www.3gpp.org), charging is the process of collecting information about chargeable events; accounting is the process of determining revenue sharing between operators in the case of roaming and other services; and billing is the process of employing specific pricing policies and issuing bills for the users. An architecture including accounting, charging, and billing is depicted in Fig. 1. The 3GPP has also joined with ETSI (http://www.etsi.org/) and Parlay organization’s content-based charging working group (http://www.parlay.org/) to deliver the Open Service Access (OSA) APIs specifications, which include accounting and charging management. These standards provide an important reference base for all accounting related matters such as record format and charging. In 3GPP’s service framework the use of the Parlay APIs was proposed [13, 14] to allow application development by third parties in order to speed up service creation and development. The standardized OSA/Parlay framework enables thirdparty independent providers to make use of the underlying network functionality without exposing the communication infrastructure to unauthorized business entities [15]. Specifically, the OSA/Parlay is the specification of a set of open standards and network-independent APIs that enable authorized service providers to control a selected range of network capabilities. The open network services offered to authorized entities concern mobility and location information management, call control and content-based charging. Current charging

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Collecting information

depending on mutual agreements between service and network providers, on the specific characteristics of the accounted services, and even on Accounting the previous user actions in other network locali(Services accessed by users through ties. Furthermore, accounting in mobile netinter-operator agreements) works should be performed independently of possible temporary disconnection and network Call data records partitioning. Figure 2 illustrates the current Billing records billing and charging methods involved in an Charging (use a charging model) Internet service provider, a mobile operator, and Call data records an application provider. Billing The Charging Accounting and Billing (CAB) (generate and send the proposal, developed within the framework of the bill to the user) MOBIVAS project [17, 18], is an integrated system targeted to support advanced business modInvoice els for service provisioning in 3G mobile systems. Subscriber This architecture supports flexible charging and billing by providing functions that adapt to the Figure 1. Accounting, charging, and billing architecture. relationship between the service provider and the operator of the home or visited network. The CAB system has been designed and implemented based on the 3GPP recommendations. entities are extended to support not only content charges but The deployment of advanced charging schemes, such as also policy-based charging, which allows the application of the content-based and location-based models, required that chargappropriate pricing policy according to user, service, or sesing records should contain all information related to the sion characteristics. chargeable events. As a result, the mobile telecommunication world arrived at the same point as the IETF: there was a need IETF — During the past several years, the explosive growth of for new mechanisms that would manage the collection of all the Internet has been exploited by application/service proinformation related to chargeable events, perform an approviders to offer their services to end users. Several Internet priate processing of this data, apply any desired flexible billing Engineering Task Force (IETF) working groups have scheme toward the users, and apportion the revenue among addressed the new requirements, which originated from the the involved players. introduction of advanced services. 3GPP’s and IETF’s requireIn response to that, groups such as the SA5 of 3GPP and ments are shown in Table 1. the UMTS Forum in the mobile telecommunication world, Moreover, the IETF has introduced new functionality with IETF’s AAA WG, and the AAA ARCHitecture Research regard to gathering and processing chargeable events, whereas Group (AAAARCH) of the International Research Task the mobile telecommunication world is shifting from a well Force (IRTF) in the Internet community, are trying to estabestablished network model toward the realization of the 3G lish the appropriate functionality and management schemes. systems, in which components in both circuit-switched and Although the IP is the glue that will tie together the Interpacket-switched networks co-exist. Hence, the existing chargnet with mobile networks, the charging models considered by ing system for messages and phone calls has been improved to 3GPP and IETF are diverse in view of the placement and address data exchange charging. management of the charging functionality. 3GPP has adopted The IETF’s Authentication Authorization and Accounting a network operator-centric model, where mobile operators (AAA) Working Group (WG) is focusing on the development plan to offer and control transport as well as information serof functional requirements for usage mediation, revenue genvices. In contrast, IETF follows a distributed approach, where eration, billing, service quality and reliability, and roaming. network providers are involved in terms of transport services, AAA [16] defines the system in IP-based networking to conand service aggregators and content/service providers are also trol which computer resources users have access to and to involved in terms of value added services and applications. keep track of the activity of users over a network. The AAA From the users’ point of view and according to the empiriWG is primarily interested in protocols regarding accounting. cal results [19], the users appreciate the flexibility of requestThe accounting and pricing issues in the Internet are also investigated in the framework of European research projects such as the Market Managed Multiservice Internet (M3I) (http://www.m3i.org), 3GPP’s requirements IETF’s requirements the Internet Next Generation (NG) (http://ing.ctit.utwente.nl/), and the Moby Dick •Dynamic pricing policy Charging based on (http://www-int.berkom.de/~mobydick/). Service providers •Automated income content and service Call data records

n

apportioning mechanism

usage

Mobile operators and Internet service providers (ISPs)

•Multi-level charging architecture •Pre-paid and post-paid schemes

Charging models used for efficient network management

Customers

One-stop billing Awareness of prices

QoS on demand (e.g., per minute rate)

STANDARDS FOR CHARGING AND BILLING The need for accounting solutions to regulate the excessive resource demand of greedy customers and to further stimulate the market for 3G service providers is recognized. In particular, accounting and charging on a per-usage basis represents important revenue for service and network providers. In addition, accounting systems should organize pricing/charging strategies

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n Table 1. 3GPP’s and IETF’s requirements. IEEE Communications Surveys & Tutorials • Fourth Quarter 2005

Application provider

ISP Billing and charging module

Billing and charging module

non-mobile goods and services, thereby creating a wealth of new CDR revenue streams for content proCDR viders and operators alike. Billing information Billing information Vodafone UK’s m-pay bill online payments solution enables mobile phone users to buy lowcost items online (Wireless CDR (call data record) is created at the end of a service. Access Protocol (WAP) or InterCustomer net) and have them charged to their mobile phone accounts as part of the Vodafone live! service. There are advantages and disadvantages to each of these Billing information methods. Whichever method is chosen, it is important that the end users understand the chargMobile operator ing scheme and feel that they are Packet-switched in control of their mobile comnetwork munications costs. C Service providers must offer a full range of next-generation serBilling and charging D Hot-spots module vices to customers on a pre-pay and post-pay basis. Content, comR merce, and communications serOther wireless vices must be supported, services whatever their basis of pricing. The same tariffs, discounts, and marketing offers must be availFigure 2. Billing and charging in network and service providers. able to each [20]. The spectacular growth of pre-paid mobile services has been a key feature of the industry. In order to ing higher QoS on demand, even if they have to pay a perachieve continued growth for next-generation services, mobile minute rate for the service. The ISPs require the introduction operators must develop an effective pre-pay customer care of new charging models that take into consideration the utiand billing strategy as part of their overall business plan. lization and sharing of network resources in order to be able There are certain challenges for pre-paid because of the addito apply efficient network management schemes and to utilize tional need for real-time processing and close integration with the bandwidth efficiently. Therefore, the network providers the network to discount users when credit expires. should be able to meter network traffic and the consumption Furthermore, the mobile operators prefer to collect all of network resources. information and apportion the revenue and exclude other application/service providers who would prefer such funcBILLING METHODS tionality to be shared among them or even to be handled by a trusted third party [21]. Thus, it is necessary to find an There are various billing methods such as billing-by-byte, in automated process that apportions the revenue based on the which charging is based on the size of the downloaded file. commercial agreements between the involved players. The iBilling on Behalf of (BOBO), which is often utilized by wiremode services handle this process by employing an informaless carriers and mobile operators, allows charges for digital tion fee collection agency by which the operator issues a bill content to be integrated into the customer’s monthly bill. on behalf of the providers (www.nttdocomo.co.jp/ Calling Party Pays is a billing method in which a wireless english/p_s/imode/). As a result, the user receives one-stop phone caller pays only for making calls and not for receiving billing. In this case, all providers will be able to collect them. The standard billing system in the United States amounts of content fees without any cost for billing, and the requires wireless phone customers to pay for all calls made mobile operator is receiving a commission on top of the and received on a wireless phone. communication charge. Premium SMS (PSMS) is a mobile billing method by which a subscriber is billed either when originating a text message to a short code requesting the content (Mobile Originated or ACCOUNTING USING MOBILE AGENT TECHNOLOGY MO billing) or when receiving the content to their phone (Mobile Terminated or MT billing). A text message contains An accounting infrastructure based on the mobile agent techthe order code, with a price attached at the cost of the connology was designed to support session-dependant usagetent item. There are limitations to the PSMS model that are based accounting [22]. This infrastructure was able to install pushing the mobile billing market into its next phase of develnew monitoring and charging behavior dynamically and was opment, whereby billing is separated from distribution via also able to initiate accounting even in the case of temporary merchant billing APIs (www.mobile365.com) . network partitioning. As a result, Portable device Usage-based Bearer-independent billing is a payment method that Pervasive Accounting (PUPA) was designed and implemented decouples the charging act from the delivery of the product or on top of the Mobile Agent (MA) platform. Accounting service. This offers greater price flexibility to content proagents maintain the same location of their mobile users, viders and a simplified purchase process for the end-user. It therefore enabling local monitoring, control, and registration also opens the door to offering higher-value transactions and of resource consumption. AAA

AAA

n


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The PUPA infrastructure is composed of two layers: • A metering layer that provides the accounting processes for the monitoring of resource consumption and for the safe storage of metering data, • A pervasive accounting layer (configuration agents and gathering agents) adopts the MA technology to dynamically enforce flexible accounting policies. The PUPA Metering Layer (ML) is capable of inspecting and making visible a wide set of system-level and applicationlevel indicators about resource consumption. At the system level it receives information on the processes working on local resources and on their usage of the communication infrastructure. For any process, it reports the process identifier, CPU usage, and the allocated memory. At the application level the ML is able to collect information about all service components accessed from within the Java execution environment and detect any invocation of a dynamically definable set of methods. The Pervasive Accounting Layer exploits the metering layer and determines how, where, and when to perform accounting and management. It is mainly implemented in terms of two types of MAs: (1) Configuration Agents (CAs) and Gathering Agents (GAs). CAs are used to tailor the service downscale and to specialize resource monitoring in accordance with the user profile. GAs are in charge of collecting accounting data of users at the end of service provisioning. PUPA keeps track of the movements of any traceable user. Once the user completes the service session, a GA is sent in the Wireless LAN where the user has roamed while accessing the service [22].

will want to more actively manage their own spending patterns. Service packages will include elements that are unfamiliar to customers, such as charging for content sessions (e.g., sporting events). Consumers may need more flexible charging methods and payment options in order to reduce the uncertain nature of the expenses associated with new services. There are various proposed economic and technical models for charging and billing for Internet usage [24–26]. Most of these, if not all, are equally applicable for use in mobile networks [27–29]. Metered Charging — In this model the consumer is charged with a monthly fee irrespective of the time spent using the mobile and network services. Once the consumers have used the time allocated to them, they will be charged for the extra usage time. This method is used in 2G networks for charging voice traffic. The duration of the call is proportional to the call’s cost. In addition, voice calls are typically circuit-switched and the user pays for the period of time the circuit is used. Hence, metered charging is simple to implement, but it is not suitable for billing 3G services. Fixed Price Charging — In this pricing model the network service provider sets a fixed rental charge for the mobile phone and all local calls are free of charge with metered charging used for non-local calls. Hence, the charging method becomes straightforward for local calls. However, this model has no added revenue for the service providers in times of above average usage on the network, and congestion may be problematic if the network is under provisioned for the number of possible users at peak times.

CHARGING MODELS IN 3G SERVICES The traditional use of monthly subscription flat rate charges in telephone billing is a model that network operators feel comfortable with. This model is so simple to implement that many new 3G service providers are tempted to apply it, and as a result many development costs will be saved. This is, however, a short-term view that could seriously damage the longterm profitability of many network operators, reduce innovation, and restrict customer choice. Flat rate pricing is popular because of its minimal accounting overhead. A flat rate encourages usage but does not offer any motivation for users to adjust their demand. Dynamic pricing models that take the state of the network into account in the price determination have been proposed as being more responsive. In general, pricing policies can be partitioned into usagebased pricing, flat rate pricing, and dynamic pricing. In usagebased pricing policies a user is charged according to a communication time or traffic volume, whereas connectionbased calls are charged by connection time and packetswitched services are charged by the transferred data volume. Dynamic pricing models take into consideration the state of the mobile network for determining the current price of a given service. Congestion-sensitive pricing as a particular dynamic pricing model has been shown to be more responsive. MacKie-Mason and Varian [23] introduced this concept in their smart market scheme. Under this model, the actual price for each packet is determined based on the current state of network congestion.

CHARGING METHODS As mobile and service providers look to offer innovative and bundled service offerings based around content, mobile commerce (m-commerce), and communication, their customers

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Packet Charging — This method is used for charging in packet-switching networks, and involves capturing and counting the number of packets exchanged in a session, without considering the time the user has spent. This model could be very costly since it requires the implementation of packet counting systems in the network and complex billing systems that can process the packet data on a customer basis. Expected Capacity Charging — This method involves an agreement between the user and the carrier regarding the amount of network capacity that will be received by the user in case of network congestion, and a fee for that level of service. The users are charged for their expected capacity and not the peak capacity rate of the network. The price is therefore fixed and predictable, which in turn allows the network provider to budget correctly for network usage. The network management system monitors all users’ excess traffic, and when congestion occurs, this traffic is either rejected or charged for. Hence, this method enables mobile carriers to achieve more stable capacity planning. Paris-Metro Charging — This method applies the concept of travel class, as used on public transport systems, to network traffic and relies on providing differentiated levels of service based on consumer usage pricing only. It provides different traffic classes, with each class distinguished by different capabilities, such as capacity, which leads to a different charge. Hence, consumers are able to assign traffic classes to their different applications based on the desired performance/cost ratio. This method is useful for providing network traffic prioritization in wireless data networks, and it enables consumers to control the cost of their network connections. The network may become self-regulating at peak capacity. When the network becomes congested and all the capacity in first


Charging types

Content, duration, event-based, flat rate, volume, etc.

Discount models

Location, payment method, time, volume, etc.

Quality of services

Bandwidth, damage, drop, loss, priority, speed, etc.

Preferences

Content, charging model, quality, service, service provider, etc.

Service characteristics

Communications, purchasing, surfing, transaction, etc.

n Table 2. Charging functions. class is filled, consumers may downgrade to second class in order to improve their own performance. Hence, this model may be suited for 3G networks and permit consumers to prioritize network traffic. For example, business emails may be considered more important than personal emails. However, the inconvenience in this method is threefold: network complexity, cost of implementation, and the overhead associated with the process of assigning traffic classes to their connections. Content-based Charging — Charging mechanisms that charge users by data volume, duration, and/or subscription almost regularly fail to reflect the inherent value of the information, i.e., the content of the data packets. The particular content of a data packet may be extremely important to one consumer, but less so to another consumer. The value of a data packet to the same consumer may also vary with time. In this model, consumers are charged based on the type of content they access. Content providers will be looking to sell their content as opposed to the airtime required to deliver the content. Moreover, content providers may be selling their content either to an operator or directly to consumers. Thus, content as well as network costs should be a component of mobile data pricing. A few challenges need to be addressed in this model, such as: • If the content provider is to be charged, then the mobile network provider may not be able to trace the service provider. • If the receiver is charged for the service, how is the receipt of unwanted (e.g., spam) messages controlled, and how do network operators stop abuses of push services? Content-based charging aims to take advantage of these challenges to further improve revenue from services provisioned. The task of identifying the packet contents is not straightforward and several 3G network nodes need to be involved. The records generated by each of these nodes, whether they are compatible with 3GPP or other international bodies, may need to be standardized in order to make them compatible for further processing. Volume-based Charging — This charging model takes into consideration the amount of data transferred. In this model the subscriber is charged based on the amount of data sent or received through the network. The advantage of this model is that subscribers are charged based on their network usage. On the other hand, the disadvantage of this model is that factors such as content type, time-of-day, and the current network status are not considered. Time-based Charging — In this model the user is charged based on the time he or she is connected to the network even if no data is transferred. Subscribers will have to pay for any amount of air-time each call connection lasts even if no one


speaks during the connection time. However, during off-peak hours subscribers will be offered a discounted rate. This model is easier to implement since the network usage time is the only parameter that needs to be recorded.

Market-based Reservation Charging — This model uses the concept of bidding and auctions used for items. In this model, subscribers have to assign monetary bids that will influence the quality of service they will receive for each of their network-based applications. Service providers will have to maintain a preference profile for each subscriber detailing the subscriber’s bids for the numerous services he or she would use. The network provider will then use the subscriber’s preference profile when routing the network traffic. The advantage is that subscribers can influence the quality of the service they are getting by the value they attach to the services they require. The disadvantage is that this model introduces uncertainty to the subscribers with regards to the quality of service in the network.

CONSTRAINTS AND CHALLENGES TO CHARGING METHODS The Call Data Records (CDRs) generated by 3G network nodes are more complex than those generated for voice and circuit-switched data services in 2G. Several external nodes, such as Cisco routers and RADIUS servers, are involved in CDR generation, especially if content-based charging is to be applied. Hence, there is the necessity of having a device capable of collecting the various CDRs from disparate network nodes, processing the records, and forwarding them to business support systems (BSS) such as the billing system. This device is know as a mediation device and is an important factor for the success of implementing a packet-based charging model. Mobile and service operators may choose to charge and bill their customers using a combination of the charging models. For example, the packet charging method could be used in both fixed price and metered charging rates for some consumers, but only use packet charging with fixed price charging for another group of consumers. Some consumers may only want to use limited mobile services, for example only voice and text emails and no multimedia messages. The mobile and service providers may chose to implement charging models to take into consideration such consumer constraints. The complicated process in calculating the tariffs for consumers could be looked at from a different perspective. The consumers are getting more control over the way they are charged for using the mobile services and the quality of service they receive from the mobile and service providers. Hence, consumers can select different levels of quality of service for various mobile services. Table 2 shows examples of different charging functions. There will be a trade-off between the complexity of the billing system to be implemented and supported and the advantage the mobile and service provider will receive for having systems in place. Fixed price charging schemes reduce the overhead of the charging and billing system infrastructure, as they tend to provide simple charging methods. Usage-based charging models provide income that is incremental and harder to predict for the network providers, as well as requiring high investment in the charging and billing infrastructure. This includes increased cost in network traffic involved in the collection of the billing data.

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Model

Peak

Off-peak

External portals/sites

$0.20/throughput minute

$0.10/throughput minute

Internal portals/sites

No charge

Premium sites

Transaction-based

n Table 3. Example of content-based charging. BILLING AND 3G SERVICES Mobile network operator and service providers in Europe are seeking ways to increase the return on their enormous network investments. New data, content, and messaging services offer them the opportunity to raise average revenue per user (ARPU), optimize average margin per user (AMPU) by lowering total cost of ownership, attract new customers, and bolster customer loyalty. However, this is only possible if operators can charge for the content and services they deliver (http://www.3g.co.uk/PR/October2004/8527.htm). Mobile operators must differentiate by offering advanced services, which allow for usage-based pricing. They need to drive down costs and grow ARPU as well as retain and generate new revenue streams. Table 3 shows an example of content-based charging models. In Korea, mobile phones have become an almost universal aid to people’s daily lives. In addition, South Korea (SK) Telecom’s 3G mediation system has become the very pulse of the network by controlling service delivery, tracking usage in real-time, and simultaneously managing data, voice, and even broadcast TV on the handset. SK Telecom’s network is using value-based billing, which charges the subscriber based on what he or she is willing to pay. With value-based billing, prices fluctuate based on factors such as a product’s quality, the time it was purchased, or the customer’s ability to pay (http://www.technology-research.com/med.htm). Mobile operators in Korea have already introduced convergent billing, which offers at the same time both past and pre-paid accounts. The benefits of converged billing are clear. It can cut time to market, rationalize customer support, and reduce churn, by enabling group discounts (http://www.cambridgenetwork.co.uk/pooled/articles/). Tiwari [30] discussed the major principles of mediation and activities involved in the design and implementation of efficient and robust mediation systems for the converging billing systems.

CDRS: EXAMPLES Generally, CDRs are created at the end of a service such as a phone call. Some of the details included in call records are: time, date, call duration, service used, caller ID information, cost, call completion status, etc. Examples of CDRs are illustrated in Tables 4a–c. Mobile and service providers keep customer profiles in their records. An example of such a profile is shown in Table 5. As a result, a detailed billing record is generated as it is depicted in Table 6. The data in Table 6 are used to calculate the customer’s rate, which calculates the service price and the discount according to the detailed billing record and the price lookup table. A simple example of a price lookup table is shown in Table 7. At the end, the bill produced to the subscriber includes all fees for network access, usage, and service. The generated rating (bill) for this specific customer is as follows: User ID: 101-2230-5252 Charge (without the network monthly fee): 96Kb × $0.04 + 30Min × $0.1 + 5Kb × $0.8 = $3.84 + $3 + $4 = $10.84 Time Discount: 96Kb × $0.05 × 0.2 = $0.96

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Advertisements have become another source of revenue for mobile service providers. For example, in France when you top-up your prepaid Bouygues Telecom account (www.bouyguestelecom.fr), the provider gives you 20 free minutes on top of the standard top-up value. However, it also comes with many advertisements of approximately two minutes each. Table 8 shows another type of bill that a network service provider may generate, in which a portion is sent to the subscriber and the remainder is kept confidential:

MOBILE GAMES New findings from Juniper Research show that JavaT downloads will generate more than $4.8 billion in mobile revenues by 2009, with mobile games accounting for the vast majority of revenues. Most of the service revenue will be generated from mobile games; with JavaT business applications still very much a developing opportunity (http://www.3g.co.uk/PR/October2004/8489.htm).

Table 4a. Billing record. User ID

101-2230-5252

Time

13:07–13:12/5 min

Content type

Game

Location

Dubai, UAE

Transaction type

Java download

Packet size

96Kb

Table 4b. Billing record. User ID

101-2230-5252

Time

12:02–12:32/30 min

Content type

WAP browsing

Location

Dubai, UAE

Transaction type

Browsing

Packet size

60Kb

Table 4c. Billing record. User ID

101-2230-5252

Time

17:12–22:22/2 min

Content type

Complex ringtone/logo

Location

Dubai, UAE

Transaction type

Download

Packet size

5Kb

n Table 4. Examples of CDRs. IEEE Communications Surveys & Tutorials • Fourth Quarter 2005

Name

Omar Ali

User ID

101-2230-5252

Customer status

Loyal

Price plan(s)

Economy; standard

Discount type(s)

Time; none

users was proposed in [33], which also gives the network provider and the game providers the possibility to charge for the service. This system is based on the UMTS technology in combination with Wireless Local Area Network (WLAN) technology. The players in this architecture could be locally or globally distributed. The billing for the game followed two approaches: separate billing and transparent billing. The separate billing approach followed two scenarios for charging for the service: • The service provider charges the user for the service, using either a pre-paid plan or an on-line credit card charge. • A billing entity within the IP backbone charges the user for the services, in which the user might be billed by multiple companies. The transparent billing approach makes sure the user deals with only one company, and the user’s subscriber identity module (SIM) card can be used for reliable billing. The service model of NTT DoCoMo [35] has previously used both billing approaches.

n Table 5. Customer profile.

Analysts predict that by the end of 2005 more than 200 million customers in the US and western Europe will play online games using wireless devices, and that games will be one of the major driving forces behind the adoption of 3G technology (http://wireless.newsfactor.com/). Today there are various wireless games: • Simple single-player games that are built into mobile phones. • Advanced single-player network games. • Two player games. In contrast to the existing wired multi-player games such as MOBILE PAYMENT FOR 3G SERVICES Age of Empires or Operation Flashpoint, these games are less appealing. These popular multi-player games require very The rapid pace of adoption of next-generation mobile handtight jitter and delay (i.e., small ping times), which makes it sets in Asia and Europe has created opportunities for new very difficult to use them on mobile phones. Games such as and innovative mobile services. Some of the most promising are mobile financial services, including mobile payments and Age of Empires require ping times below 300 msec, whereas banking services [36]. Mobile banking services are valued by Operation Falshpoint requires ping times below 150 msec [31]. users because of the inherent time and place independence, On the other hand, the bandwidth needed to play these games and the overall effort-saving qualities. is typically small. The shift from physical to virtual payments has brought Round trip delays of approximately 2.4 sec are experienced enormous benefits to consumers and merchants. However, it by wireless players who are connected to the Internet via a has put extra pressure on payment service providers, including GSM air interface [32]. Hence, given these large round trips, banks and card companies, and mobile operators, to provide it is almost impossible to support multi-player sessions over robust security and interoperability. The advent of mobile the GSM air. Even though 3G wireless technologies may propayments has added another layer of complexity through the vide smaller round trip delays, it is expected that they will not use of constrained devices with different capabilities and netbe able to meet the tight delay requirements of multi-player work limitations. games [33]. Mobile personal devices are beginning to be used to The majority of mobile games on the market are individual perform secure banking, payment, and other transactions. games. However, mobile operators have requested more roleMobile personal devices are a convenient means for playing games (RPG) from game developers as a way to increase revenues [34]. Individual games are only downloaded once and are a one-time payment to User ID 101-2230-5252 the operator. However, RPGs typically require a connection to the network to interact with other 13:07–13:12/5 min; 12:02–12:32/30 min; players, providing a profitable stream of revenues Time(s) 17:12–22:22/2 min to mobile operators. That creates an ambiguous future for mobile RPGs. Game developers are Content type(s) Game; WAP browsing; complex ringtone/logo hesitant to develop more RPGs because of their low profits due to the high data costs of playing Location Dubai, UAE them. They realize the games would be much more popular if flat-rate data plan connections were available. Flat-rate data plans for gaming Transaction type(s) Download; WAP browsing; complex ringtone/logo usually impede the revenues of mobile operators, especially when extreme gamers are willing to Packet size(s) 96Kb; 60Kb; 5Kb pay a high cost to play. Games played by multiple users, each using a Price plan(s) Economy; standard wireless terminal such as a PDA, offer tremendous revenue potential for 3G systems. A system Discount type(s) Time; none architecture for billing multi-player games in a wireless environment has been designed [33] that Name Omar Ali enables high-quality games among multiple wireless users and at the same time enables network User ID 101-2230-5252 service providers and game service providers to charge for the gaming service. Customer status Loyal A system architecture that enables high quality multi-player sessions in a wireless format for Table 6. Detailed billing record.

n


65

Java download

Economy

Standard

Price rate

$0.04/Kb

$0.05/Kb

Time discount

20%

0%

Price rate

$0.09/Min

$0.1/Min

Time discount

10%

0%

Price rate

$0.76/Kb

$0.8/Kb

Time discount

5%

0%

WAP browsing

Complex ringtone/logo

n Table 7. Price lookup.

devices, and are the most common form of transaction software offered by the developing mobile payments market. This technology is very crucial for wireless Web shoppers since it allows users to store billing and shipping information. Users can access such information through one click while shopping from a mobile device. POS transactions are traditional retail-store payments. Users are allowed to enter a store and make purchases by using their wireless devices instead of a credit card. Peer-to-peer transactions enable online monetary transfers between individuals. PayPal offers a digital payment for both e-commerce and m-commerce peer-to-peer transactions. PayPal includes wireless capabilities for peer-to-peer payments, which can be sent from any wireless device to any business that uses a mobile solution platform incorporating PayPal’s payment service [39].

authorizing transactions. In the near future, they are likeMOBILE SERVICES IN ASIA-PACIFIC ly to incorporate low-cost enhancements providing secure, signed transaction requests, providing third-party verifiMany western countries are still looking up to Japan as a pilot able proof of the consumer’s agreement for each transacproject for multimedia services in particular and 3G services tion [37]. in general. In addition, current mobile phones are coming In the meantime, high-speed data networks, such as with myriad designs, a wide range of capabilities, and relative2.5G and 3G, with more sophisticated data-enabled wirely high quality. This has helped the 3G systems to start an upturn. In many Asian countries mobile phones with color less devices, have the potential to transform the payment screens and general packet radio services (GPRS) data access process. Color screens, greater bandwidth, and more comare the key ingredients for mobile messaging, and will encourpelling content are converging to create an environment in which consumers feel more comfortable transacting on the age consumers to experiment with the newly developed sermove. In addition, new wireless protocols, such as Bluevices. tooth, infrared and radio frequency identification (RFID), International Data Corporation (www.idc.com) has projectare enabling short-range wireless device-to-device payed that the number of mobile service subscribers in the AsiaPacific region (outside of Japan) is expected to exceed 901 ments. million by 2009 after growing by more than 25 percent to Mobile payments are expected to become one of the most more than 527 million in 2004. Some of the main factors important applications in m-commerce [38]. They are comboosting growth in the region include the increasing popularimonly categorized into micro-payments and macro-payments ty of pre-paid plans, as well as continued network expansion with the distinction between the two occurring at approxiin emerging markets, extending the reach of mobile services mately $10, and are further subdivided into remote and prox(www.mobile365.com). imity payments, depending on whether the purchase takes China is the world’s largest mobile market with nearly 330 place at the point-of-sale (POS) or remotely via an electronic million mobile phone subscribers (http://wireless.sys-con.com); network. In order to facilitate the credit card process, many companies have introduced electronic walSubscriber activities Network fee Download let (e-wallet) technology, which stores e-checks, e-cash, and credit card information, and is used Amount of data 10 MB to keep track of billing and shipping information so that this information can be entered easily Monthly subscription $6.00 with one click at participating merchants’ sites [39]. Type of charge $0.50 per MB Mjolsnes and Rong [40] proposed a generalization of the architecture of e-wallet. Their Prices $6.00 $5.00 model envisages that most of the content of the e-wallet is kept at the residential electronic keeper, while roaming with one favorite mobile termiAllocation to operator 100% 30% nal. Their architecture solves the problem of multiple credential issuers that must fit into mulAllocation to advertiser 0% 20% tifunctional smart cards at the mobile terminal. This model solves the multi-issuer problem of Allocation to partner 0% 50% hardware credentials by exploiting on-line mobility of the user’s device, which is becoming availRevenue to operator $6.00 $1.50 able with 3G. Numerous electronic payment options are Revenue to advertiser $0.00 $1.00 available via wireless devices, including mobile wallets (M-wallets), POS transactions, and peerRevenue to partner $0.00 $2.50 to-peer transactions. M-wallets have been introduced as e-wallets accessible through wireless Table 8. Compound bill.

n

66


one estimate for the value of China’s wireless, mobile valueadded service market put it at more than $4 billion. In China the method used to deliver the content determines how the content can be charged. For example, in the majority of countries today around the world, a polyphonic ring tone delivered by WAP push is charged by PSMS. In China, however, this billing process is illegal. If you wish to charge for a polyphonic ring tone, it must be billed and delivered via WAP or multimedia messaging service (MMS) (www.mobile365.com). India is one of the fastest growing mobile markets in the world. According to the Telecom Regulatory Authority of India (http://www.trai.gov.in), during the first quarter of 2005 there were approximately 60 million subscribers, growing at over two million a month. By the end of 2005, the Indian market is predicted to hit 80 million subscribers. The growth is being fueled by the lowest national call rate in the world as of 2005: three cents a minute anywhere, anytime, across any mobile network. Vodafone (http://www.vodafone.com.au/) invested more than $2.7 billion in establishing its GSM and GPRS network operations in Australia. The firm owns approximately 20 percent of the market and estimates third-party revenue from mobile content was $13 million in March 2005. This gives a projected annual turnover of around $200 million for thirdparty content and services. Telstra and Optus are the next two largest operators in the Australian market and together have 70 percent market share. So far, however, WAP billing has been limited in Australia. Telstra offers a WAP-like experience through its iMode service and each operator offers WAP billing for their own content services, such as Optus Zoo.

CONCLUDING REMARKS Mobility and nomadicity are fast becoming integral parts of the chosen mode of the anytime, anywhere communications paradigm. Increasingly, service providers rely on multiple platforms for their communications access and core network wireline, cellular/personal communications service, and wireless fidelity (WiFi). At the same time, the end user community wants familiar and often personalized services, regardless of how they access the mode of communication (http://www. atis.org). To survive in the rapidly expanding and changing IP-based services market, service providers need to develop new and dynamic billing and accounting solutions. The traditional flat rate, monthly service subscription models with fixed costs are no longer valid for today’s service market. It is widely accepted among consumers and providers that accounting and billing for emerging 3G services will be content-based and usage-based. In any case, spending on IT systems and billing is likely to change significantly for the worse. It is expected that network operators will have to take into account changes in their cost structures, particularly compared to their past experience with GSM systems. According to the Gartner Group (www4.gartner.com), mobile services are moving from hierarchical architectures based on circuit switching to distributed and layered architectures based on packet routing. As a result, it is estimated that infrastructure costs may not increase in fact as much as other support costs in the long-run. However, heavy investment in network management, billing systems, massive marketing, support devices, and handset subsidies are an inevitable part of the future. Moreover, the costs of billing systems in particular will rise sharply, since “always-on” services will very likely disallow the relevance of per-minute charging. In addition, amid strong competition


and high consumer churn rates, Forrester predicts that marketing costs in particular will increase significantly before subsiding again after 2008. The key challenge operators face is the development of value added services for their customers. These services will create the communications revolution and complement the existing mobile communications experience. For the operator this will mean attracting large numbers of customers and securing an ARPU level that delivers their 3G business cases [41]. Adding intelligence to 3G service assurance allows the customer experience to be measured, and it makes it possible to efficiently determine the cause of problems that occur and decide on the remedial actions to be taken. It is only with this kind of capability that the customer experience can be truly assured in 3G. 3G service assurance will be driven by business needs rather than the technology approach of 2G. Basically, 3G service assurance is about ensuring that the customer has a quality experience when accessing 3G services. This is particularly important initially where the network operator’s brand and the reputation of 3G are at stake. Certainly, the cumulative costs of building a UMTS network will be different for incumbents and for new entrants. New entrants with no existing GSM infrastructure to reuse face very high costs, estimated at US$6.2 billion for the Sonera/Telefonica alliance in Germany [42]. A Gartner Group analysis of the mix of operators’s cost yields a hypothesis that marginal costs of servicing a thousand new subscribers will rise from an average of $200 per subscriber for a GSM network to around $350 per subscriber on a UMTS network [43]. UMTS and Wireless Local Area Networks (WLANs) are viewed as competing technologies in 3G wireless services. Security and billing in 3G services represent the strengths in both technologies, with an addition of high-speed service in WLANS. However, one of the major weaknesses of 3G services is the limited bandwidth. Moreover, the combination of UMTS and WLAN into an integrated fourth-generation (4G) mobile communication environment will enable users to access IP services ranging from low-speed to high-speed in cases of WiFi hot spots. This evolution will bring more players into the control and sharing of the cost of mobile services [44].

REFERENCES

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BIOGRAPHY

ZOHEIR EZZIANE ([email protected]) is currently an associate professor of information technology at Dubai University College, UAE. He received his Ph.D. in engineering from Florida Atlantic University, USA in 1994. His research interests are in the areas of 3G systems, mobile commerce, evolutionary systems, multi-agent systems, information systems, and nano technology. He has published many articles in professional journals such as the International Journal of Mobile Communications, Expert Systems with Applications, Cybernetics and Systems, International Journal of Intelligent Systems, Artificial Intelligence for Engineering Design, Analysis and Manufacturing, Logistics Information Management, and Expert Systems: The International Journal of Knowledge Engineering and Neural Networks, and others.
