Revenue and Traffic Expectations

The future traffic in terms of transmitted bits will be dominated by data- andpacket-oriented traffic [39, 40]. Generally, it is expected that the revenueIntroduction 15Table 1.7Standardized DSRC SystemActive BackscatterOrganization ARIB CENRF carrier spacing 10 MHz 1.5, 12 MHz (medium data rate);10.7 MHz (high data rate)Allowable occupied bandwidth Less than 8 MHz 5 MHz (medium data rate);10 MHz (high data rate)Modulation method ASK (uplink/downlink) ASK (downlink)/PSK (uplink)Data coding Manchester code FMO (downlink)/NRZI (uplink) from data services will exceed the revenue from voice in the near future (seeFigure 1.9) [41]. Analysts expect that the average revenue per user (ARPU)will be shifted from voice to nonvoice services (see Figure 1.10) [42]. Thisshift from voice to data services and the related revenues will be facilitated bya heterogeneous network architecture to support user needs of optimally connectedanywhere, anytime, depending on service requirements, user profiles,and location.The nonreal-time traffic is expected to be mainly asymmetric with thefollowing different types of asymmetry:• User-personal view: The degree of asymmetry for traffic betweendevices of a personal area network (PAN);• User-centric view: The degree of asymmetry for the traffic between aspecific user and the network for a specific service;• Cell-centric view: Degree of asymmetry in specific cells;• Network view: Degree of asymmetry in the entire network.The Universal Mobile Telecommunication Systems (UMTS) Forum,ITU, and the Japanese Telecommunications Council are expecting increasingtraffic asymmetries from the network view according to Figures 1.11 and1.12 [43, 44]. Figure 1.11 shows the expected spectrum demand for uplinkand downlink, whereas Figure 1.12 describes the asymmetry in terms of relativetraffic in uplink and downlink. Because the ratio of network-centric