WiMAX IEEE 802.16 family :.
• IEEE 802.16a: The standard specifies the operation from 2GHz to 11GHz, both licensed and license exempts. Because the signals at lower frequency can penetrate barriers and thus a line-of-sight connection between the transceiver and receiver is not required, most commercial interests have focused mainly on the lower frequency ranges. Under this premise, IEEE 802.16a standard was thus completed in January 2001. It enables the WiMAX implementations with better flexibility while maintaining the data rate and transmission range. IEEE 802.16a also supports mesh deployment, which can extend the network coverage and increase the overall throughput.
• IEEE 802.16b: This extension increases the spectrum to the 5 and 6 GHz frequency bands, which provides QoS guarantee to ensure priority transmission for real-time applications and to differentiate service classes for different traffic types.
• IEEE 802.16c: As the Work Group’s initial interest, IEEE 802.16c defines a 10 to 66 GHz system profile that standardizes more details of the technology. These high frequency bands have more available bandwidth, but the signals cannot diffract the obstacles and require line of sight deployment.
• IEEE 802.16d: Approved in June 2004, IEEE 802.16d upgrades the 802.16a
standard. This extension aims to improve performance for 802.16 especially in the
uplink traffic.
• IEEE 802.16e: This technology standardizes networking between fixed base stations (BSs) and mobile base stations (MSs), rather than just between base stations and fixed recipients. IEEE 802.16e enables the high-speed signal handoffs necessary for communications with users moving in vehicles. It promises to support mobility up to speeds of 70-80mi/h. The subscriber stations (SSs) could be personal communication devices such as mobile phones and laptops.
We will continue the family next posts .
