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Điện thoại di động mạng lưới Radio P10

10 Wireless Local Loop Systems Wireline communications networks are expensive and time-consuming to configure. Growing demand for telecommunications services and the imminent liberalization of the telecommunications market in Europe have greatly increased the interest in radio-based communication (Wireless Local Loops, WLL), also referred to as Radio in the Local Loop (RLL), see [3]. Future competitors of telecommunications monopoly service providers, such as power suppliers who already have their own wide-area networks, will usually lack access networks to the end users | Mobile Radio Networks Networking and Protocols. Bernhard H. Walke Copyright 1999 John Wiley Sons Ltd ISBNs 0-471-97595-8 Hardback 0-470-84193-1 Electronic 10 Wireless Local Loop Systems Wireline communications networks are expensive and time-consuming to configure. Growing demand for telecommunications services and the imminent liberalization of the telecommunications market in Europe have greatly increased the interest in radio-based communication Wireless Local Loops WLL also referred to as Radio in the Local Loop RLL see 3 . Future competitors of telecommunications monopoly service providers such as power suppliers who already have their own wide-area networks will usually lack access networks to the end users. Message transfer over existing power supply lines is currently being attempted using CDMA transmission and allows rates of several Mbit s. The CEN 50 065 standard which enables the use of carrier frequencies of up to 140 kHz is available for this purpose. In 1997 Northern Telecom conducted its first field tests in this area in Great Britain. If successful the power supply network could be used in the future as a user access network for voice and data services playing a major role in promoting competition and price reductions in telecommunications services. Meeting the following requirements wireless technology is very effective at bridging the last mile of the path between the fixed network access of private network operators Point of Presence POP and the user Fast and economic network configuration Economic network operations Flexible and expandable network structure Possible added-value through restricted mobility For the user a connection over a WLL system replaces the wireline fixed network connection and should guarantee the same quality of service characteristics bit-error ratio delay time and blocking probability as the public analogue telephone network Public Switched Telephone Network PSTN or even the Integrated Services Digital Network ISDN. .