First manufactured by ArrayComm and later on adopted as the High Capacity ? Spatial Division Multiple Access (HC -SDMA) radio interface standard (ATIS-0700004-2005) by the Alliance of Telecommunications Industry Solutions (ATIS, this wireless broadband technology favours the utilization of its bandwidth with the help of smart antennas. This mobile broadband wireless access system also called the HC-SDMA or High Capacity Spatial Division Multiple Access, has the HC-SDMA interface that offer wide-area broadband wireless data-connectivity for fixed, portable and mobile computing devices and appliances. Designed and implemented with smart antenna array techniques to substantially improve the radio frequency (RF) coverage, capacity and performance for the system, the protocol has the following features -:
it describes base station and client device RF characteristics, including output power levels, transmit frequencies and timing error, pulse shaping, in-band and out-of band spurious emissions, receiver sensitivity and selectivity
it classifies the associated frame structures for the various burst types including standard uplink and downlink traffic, paging and broadcast burst types
it clearly states the modulation, forward error correction, interleaving and scrambling for various burst types
it describes the various logical channels (broadcast, paging, random access, configuration and traffic channels) and their roles in establishing communication over the radio link
it states the procedures for error recovery and retry. The protocol supports well the Layer 3 (L3) mechanisms such as the creation and controlling of logical connections (sessions) between client device and base that includes the registration, stream start, power control, handover, link adaptation, stream closure, client device authentication and secure transmission on the data links. Currently having a connectivity speed of 1 Mbit/s, the speed can be increased to 5 Mbit/s in future with the use of HC-SDMA protocol.
The currently available commercially access options are
? iBurst Desktop modem with USB and Ethernet ports (with external power supply)
? iBurst Portable USB modem (using USB power supply.