IEEE releases spec for high-speed wireless streaming
By John Blau
IDG News Service
Home and small-business users seeking to connect bandwidth-hungry audio and visual devices will appreciate a new IEEE standard for streaming multimedia data over high-speed wireless networks.
The 802.15.3 standard for high-rate wireless personal area networks (WPAN) allows these networks to link as many as 245 wireless fixed and portable devices at data rates up to 55M bit/sec and at distances from a few centimeters to 100 meters, the IEEE said Wednesday.
The standard, which substantially increases the initial 1M bit/sec 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 11M, 22M, 33M, 44M and 55M bit/sec.
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 bit/sec, while the transmission speed of a device 100 meters away drops to 22M bit/sec.
The highest rate, 55M bit/sec, is necessary for low-latency, multimedia connections and large-file transfers, while 11M bit/sec and 22M bit/sec rates are ideal for long-range connectivity for audio devices, the IEEE said.
Moreover, 802.15.3 offers reliable quality of service, the IEEE said. It uses 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 data protection.
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.
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