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WIDE-AREA UBIQUITOUS NETWORK: INFRASTRUCTURE FOR SENSOR AND ACTUATOR NETWORKING
2.1 INTRODUCTION
The growth of Internet traffic has been at a sustainable rate because of the increase of the rate of wired/wireless access lines, which is a product of the high-speed competition among network providers—for example, from ADSL to FTTH or from a third-generation cellular network to long-term evolution. As a result of this intense competition, the number of broadband subscribers has increased rapidly, and the price of communications services has decreased, although the speed of the services has increased (Figure 2.1). In addition, many network providers have introduced fixed-rate charging. Fixed-rate charging was used for wired network services but cellular network providers have also introduced it, mainly for data services (Figure 2.2). Under this charging system, the network operator’s revenue does not increase even if the traffic drastically increases. However, it is difficult for the network providers that have already introduced fixed-rate charging to discontinue it because it is attractive to heavy users and is an essential tool for keeping these customers.
Figure 2.1. Price of broadband access in Japan. (This price is that of the typical ADSL/FTTH services provided by NTT-East.) Data source: http://www.johotsusintokei.soumu.go.jp/whitepaper/html/H1401000.html.
Figure 2.2. Number ...
