Selectable channel band- bandwidths 28MHz widths between 1.25MHz widths between 1.25MHz and 20MHz, with up to 16 and 20MHz, with up to 16 logical subchannels logical subchannels Bit rate 32Mbps-134Mbps (at Up to 75Mbps (at 20MHz Up to 15Mbps (at 5MHz 28MHz channelization) channelization) channelization) Modulation QPSK, 16-QAM, 64-QAM OFDM, OFDMA, QPSK, OFDM, OFDMA, QPSK, 16-QAM, 64-QAM, BPSK 16-QAM, 64-QAM, BPSK Mobility Fixed Fixed and portable Regional roaming Typical cell 1-3 miles (1.5-5 km) 3-6 miles (5-10 km), max. 1-3 miles (1.5-5 km) radius range 30 miles (50 km) WMANs Three major phases of development are associated with WiMax: Phase 1: Fixed-location private-line and/or hotspot backhaul-This phase involves dedicated facilities using outdoor antennas, supporting up to 100Mbps. Equipment providers are seeing an international market for such point-to-point systems, supporting basic voice services as well as cellular backhaul. With the continuing growth in hotspots, WiMax presents a solu- tion to aggregating the traffic and backhauling it to a central, high-capacity Internet connection. Phase 2: Broadband wireless access-One of the first mass-market appli- cations for WiMax is intended to be wireless DSL. The data rates supported will range from 512Kbps to 1Mbps. The WiMax Forum anticipates growth in this phase as large carriers begin deploying low-cost products. Phase 3: Nomadic or mobile applications-In this phase, new develop- ments, such as Mobile WiMax, are expected to also support moving users, traveling at speeds up to 75 mph (120 kph). It will operate at lower fre- quencies, below 6GHz, and is planned to operate on a shared channel of 15Mbps and to support user data rates of 512Kbps. In the 2006-2007 time frame, it is expected that WiMax will be incorporated into end-user devices such as notebook computers and PDAs along with Wi-Fi and Bluetooth. Also in the 2007 time frame, it is expected that WiMax will be inte- grated into 3G phones along with Wi-Fi. In the long-term future, it is expected that 