se user group. Despite their inherently shorter range, WPANs are also susceptible to a range of security threats and appropriate security measures should be considered, in line with the level of risk to user data from unauthorised access. WIRELESS MAN IMPLEMENTATION Introduction Although Wi-Fi has provided a basis for many small to medium scale metropolitan area networking initiatives, it is only with the completion of standards specifically aimed at providing wireless "last mile" solutions, such as IEEE 802.16, that the prospect has opened up of more widespread MAN applications. The key requirements for metropolitan area networking are; Scalability to hundreds or thousands of subscribers rather than perhaps tens or hundreds of users on a LAN Flexibility to provide access for a wide range of different service types, including mechanisms for requesting and allocating bandwidth Guaranteed quality of service (QoS) when required by individual subscribers or services. Despite the recent advances discussed in Chapter 6, LAN standards such as IEEE 802.11 still fall short of providing these requirements, hence the need for specific standards to address the requirements for metropolitan area networking. In Chapter 12 the IEEE 802.16 standards will be described, focussing on how these key requirements have been achieved. 802.16's European Part Five sibling HIPERMAN, which has been developed by ETSI alongside the IEEE standard, will also be briefly covered. Chapter 13 will address MAN implementation, covering the design and start-up of a wireless metropolitan area network or its rural equivalent. This will cover technical planning and implementation aspects - site surveying, equipment planning and installation - and also the business planning aspects - customer mapping, competitor analysis and management and financial planning. CHAPTER Wireless MAN Standards The 802.16 Wireless MAN Standards Origins and Main Characteristics The IEEE 802.16 set of standards have been developed since 1998 in response to the need for a wireles