Why is 16e better for mobility?
802.16e contains enhancements over the 802.16d standard that facilitates indoor operation and mobile access. Scalable OFDMA – A scalable physical layer enables optimum performance delivery in channel bandwidths ranging from 1.25 MHz to 20 MHz with fixed sub-carrier spacing for both fixed and portable/mobile usage models, while keeping the product cost low. The concept of scalability was introduced to the PHY in 802.16e. Sub-Channelization – Sub-channeling concentrates the transmit power into fewer carriers effectively increasing the system gain. Increased gain can be used to extend the reach of the system, overcome the building penetration losses, and or reduce the power consumption of the CPE. This is particularly useful for mobile applications where significant usage will occur indoors-at homes, café and offices. MIMO – WIMAX PHY layer takes advantage of time diversity through interleaving, frequency diversity through OFDM and spatial diversity through MIMO techniques. Antenna divers
