August 08, 2003, 9:10 AM — Home and small-business users seeking to connect bandwidth-hungry audio and visual devices will appreciate a new IEEE (Institute of Electrical and Electronics Engineers) standard for streaming multimedia data over high-speed wireless networks.
The new 802.15.3 standard for high-rate WPANs (wireless personal area networks) allows these networks to link as many as 245 wireless fixed and portable devices at data rates up to 55M bps (bits per second) and at distances from a few centimeters to 100 meters, the IEEE said Wednesday in a statement.
The standard, which substantially increases the initial 1M bps speed of WPANs, comes in response to strong demand from users, the IEEE said. Users want to connect multiple portable devices at low cost, yet run high-bandwidth applications, such as multimedia, digital images and high-quality video. The standard also addresses user priorities such as network economy, frequency performance, power consumption and data-rate scalability, the IEEE said.
To keep costs low the IEEE limited the need for external components and allowed the radio and protocol to appear on no more than two chips that fit within a compact flash card, it said.
The new WPAN standard uses the 2.4 GHz unlicensed frequency band and specifies raw data rates of 11, 22, 33, 44 and 55M bps.
Distance plays a role in transmission speed. The closer the device is to the access point, the higher the bandwidth. For instance, a device up to 50 meters away from an access point can transmit data at a speed of 55M bps, while the transmission speed of a device 100 meters away drops to 22M bps.
The highest rate, 55M bps, is necessary for low-latency, multimedia connections and large-file transfers, while 11M bps and 22M bps rates are ideal for long-range connectivity for audio devices, the IEEE said.
Moreover, 802.15.3 offers reliable QoS (quality of service), the Institute said. It uses TDMA (time division multiple access) to allocate channel time among devices to prevent conflicts and only provides new allocations for an application if enough bandwidth is available.
Fixed and portable devices in a WPAN connect in an ad hoc way and communicate by peer-to-peer networking, allowing them to connect without user intervention. The AES 128 (advanced encryption standard), approved by the U.S. government in 2001 to replace the older DES (data encryption standard), ensures that data is protected in the network.
The 802.15.3 standard allows networks based on this specification to coexist with other 802.15 WPANs, such as Bluetooth systems, and with 802.11 WLANs, especially 802.11b and 802.11g, which also operate in the 2.4 GHz band.