This chapter provides an overview of differences and purposes of the emerging technologies in the wireless sector. The three primary areas of discussion are fixed wireless, mobile wireless, and optical wireless technology.

We began with a discussion of the fixed wireless technologies that include Multichannel Multipoint Distribution Service (MMDS), Local Multipoint Distribution Service (LMDS), Wireless Local Loop (WLL) technologies, and the Point-to-Point Microwave technology. The primary definition of a fixed wireless technology is that the transmitter and receiver are both in a fixed location. Service providers consider MMDS a complementary technology to their existing digital subscriber line (DSL) and cable modem offerings; LMDS is similar, but provides very high-speed bandwidth (it is currently limited in range of coverage). Wireless Local Loop refers to a fixed wireless class of technology aimed at providing last mile services normally provided by the local service provider over a wireless medium. Point-to-Point (PTP) Microwave is a line-of-sight technology that can span long distances. Some of the hindrances of these technologies include line of sight, weather, and licensing issues.

In 1997, the Institute of Electrical and Electronics Engineers (IEEE) announced the ratification of the 802.11 standard for wireless local area networks. The 802.11 specification covers the operation of the media access control (MAC) and physical layers; the majority of 802.11 implementations utilize the DSSS method that comprises the physical layer. The introduction of the standard came with 802.11 followed by 802.11b. Then along came 802.11a, which provides up to five times the...