WiMAX:
The IEEE 802.16 Air Interface Standard is truly a state-of-the-art
specification for fixed broadband wireless access systems
employing a point-to-multipoint (PMP) architecture.

In order to ensure interoperability between vendors equipment, the
WiMAX technical working groups have completed the work for 10 to
66 GHz and has started work for the sub 11 GHz part of the
standard.

This requirement eases the effect of multipath, allowing for wide
channels, typically greater than 10 MHz in bandwidth.

The standard is designed to accommodate either Time Division
Duplexing (TDD) or Frequency Division Duplexing (FDD) deployments,
allowing for both full and half-duplex terminals in the FDD case.

The MAC [Media Access Control] was designed specifically for the
PMP wireless access environment. It supports higher layer or
transport protocols such as ATM, Ethernet or Internet Protocol
(IP), and is designed to easily accommodate future protocols that
have not yet been developed. The MAC is designed for very high bit
rates (up to 268 mbps each way) of the truly broadband physical
layer, while delivering ATM compatible Quality of Service (QoS);
UGS, rtPS, nrtPS, and Best Effort.

The 802.16 MAC uses a variable length Protocol Data Unit (PDU)
along with a number of other concepts that greatly increase the
efficiency of the standard.

Practical cell sizes usually have a small radius of around 5 miles
or less.

Data rates vary according to modulation rates (1.75MHz to 20MHz)
and modulations (QPSK and QAM) to achieve 1Mbs to 75Mbs.

73's
Richard Clark, KB7QHC