When 3G standardization activities were initiated by ITU in 1992, only vague ideas existed regarding the type of services and applications that would be supported. Ten years later thoughts on these subjects have matured, despite the fact that we cannot rule out the possi- bility of future, yet unforeseen, demands.
The difference between services and applications needs to be defined [18]. Apart from the concept of services and applications, this definition entails the concepts of content and device.
Services are combination of elements that service providers may choose to charge for sepa- rately or as a package. Applications allow services to be offered users. Applications are invisible to the user and do not appear on the bill. What the user sees and pays for is the
content, which is offered through applications running on devices. The definition of services and applications is illustrated in Figure 5.3:
† A user subscribes and pays for services. Services are through applications, which in turn deliver the service content to the user.
† Devices execute the applications needed to deliver the service content.
† The service provider offers services using applications running on devices.
In the remainder of this section we make a brief presentation of the 3G service classes from the point of view of offered capacity. This is followed by a nonexhaustive list of representa- tive 3G applications [18].
5.3.1 Third Generation Service Classes
The deployment of 3G networks does not imply instantaneous change of users demands for certain services. We expect that voice traffic will continue to possess the lion’s share in the first years of 3G network operation, with the demand for multimedia services increasing as time passes. In the following, we summarize, in order of increased capacity demand, the main service classes that will be offered by 3G networks [9]. Although none of them are set in hardware yet, they are useful for providers planning coverage and capacity. Furthermore, 3G terminals will probably be rated according to the level of service they offer, providing increased performance/cost ratios to users.
† Voice and audio. Demand for voice services was the reason for the big success of 1G and 2G systems. The need for voice communication will continue to dominate the market, accompanied by demands for better quality. Different quality levels for voice commu- nication will be offered, with higher qualities having higher costs. The capacity required by this service class is the lowest, and 28.8 kbps provides substantial support for good quality voice calls.
† Wireless messaging. Current 2G systems support rather primitive means of messaging (e.g. the SMS message comprises a maximum of 160 characters). 3G wireless messaging will allow cellular subscribers to use their terminals to read and respond to incoming e- mails, open and process e-mail attachments, and handle terminal-to terminal messages.
Depending on the desired speed of message transfer, the capacity demanded by this service class can vary, however, speeds around 28.8 kbps should be more than sufficient.
Third Generation (3G) Cellular Systems 159
Figure 5.3 Definition of services and applications
† Switched data. This service class includes support for faxing and dial-up access to corpo- rate LANs or the Internet. As far as file transfer is concerned, speeds like those of today’s fast modems (56 kbps) are required in order to shorten the time a user spends on-line and thus the associated cost of file transfers.
† Medium multimedia. This should be the most popular service class introduced by 3G. It will enable web browsing through 3G terminals, an application already proving very popular [5]. This service class will offer asymmetric traffic support. This is because in web sessions, the traffic from the network to the terminal (downlink or forward-link traffic) is always much higher than the traffic in the reverse link (uplink or reverse-link traffic).
This service class will also support asymmetric multimedia applications such as high- quality audio and video on demand. Speeds up to the maximum (2 Mbps) will be offered at the downlink. Speeds around 20 kbps for the uplink will be enough.
† High multimedia. This service class will be used for high-speed Internet access and high quality video and audio on-demand services. It will support asymmetric traffic offering the highest possible bit rates in the downlink. In the uplink, speeds in the order of 20 kbps will suffice.
† Interactive high multimedia.This service class will support bandwidth-hungry, high-qual- ity interactive applications offering the maximum speeds possible.
5.3.2 Third Generation Applications
The advanced service classes introduced by 3G networks will enable a wide range of end-user applications that will be either completely new or just mobile versions of applications already running on wired systems. In this subsection, we briefly present some of the 3G applications that will probably be popular among the user community [18].
† Multimedia applications. Video telephony and videoconferencing will be typical mobile multimedia applications. The increased capacity offered by 3G systems will enable use of such applications in a cost-efficient manner. Users will be able to participate in virtual meetings and conferences through their 3G terminals. Furthermore, they will have the ability to use audio/visual transport applications that will deliver multimedia content, such as CD-quality music and TV-quality video feeds, from service platforms and the Internet.
† Mobile commerce applications. Mobile commerce (m-commerce) is a subset of electronic commerce (e-commerce). m-Commerce will introduce flexibility to e-commerce. As most people keep their handsets with them at all times, they will have the ability to make on-line purchases and reservations upon demand without having to be in front of an Internet- connected PC. Market analysts predict that e-commerce will be a multitrillion dollar industry by 2003. Introducing e-commerce to the mobile platform will be an important source of operator revenue. The increased capacity of 3G systems will offer efficient support for massive use of m-commerce applications.
† Multimedia messaging applications. These applications will handle transport and proces- sing of multimedia-enhanced messages. Users will be able to use their 3G terminals to send and receive voice mails and notifications, video feed software applications and multimedia data files. Having a single mailbox on the same terminal for these messages will greatly increase time efficiency for the end user.
† Broadcasting applications. Such applications will typically use asymmetric distribution
infrastructures combining high capacities in the downlink with low capacities in the uplink. Multimedia news broadcasting, interactive games and location-based information services, such as flight information in airports are examples of such applications.
† Geolocation-based applications. Geolocation technology determines the geographical location of a mobile user. There are two types of geolocation techniques, one based on the handset and the other on the network. The first uses the GPS system to determine user location while in the second, the replicas of the signals from the same handset at different base stations are combined in order to determine user location. Some obvious applications employing geolocation technology include mobile map service and identification of user location for emergency calls.