Introduction to 802.16m(WiMAX Advanced)

There are various WiMAX standards published by WiMAX Forum as 802.16 series of IEEE standards. It is the short form of Worldwide Inter-operability for Microwave Access. It is developed to provide both fixed as well as mobile broadband wireless link. There are different versions of the wimax standard known as WiBro(used in Korea), Fixed WiMAX(802.16d) and Mobile WiMAX(802.16e). Fixed WiMAX uses OFDM modulation scheme and Mobile WiMAX uses OFDMA modulation scheme. Refer OFDM vs OFDMA to know comparison between them. IEEE 802.16m standard is also known as wimax advanced.

IEEE 802.16m basics

802.16 is a series of Wireless Broadband standards developed by IEEE for Wireless Metropolitan Area Networks.

802.16 standards are also called as 'WiMAX' (Stands for Worldwide Interoperability for Microwave Access) by the WiMAX Forum. WiMAX falls under two major categories viz. fixed WiMAX and mobile WiMAX. Fixed WiMAX is based on OFDM Physical layer and MAC layer defined in the standard and Mobile WiMAX is based on OFDMA PHY/MAC. WiMAX forum promotes and certifies compatibility and interoperability of products based on published specifications after approval.

802.16e-2005 standard based products are deployed around the world which is popularly called as Mobile WiMAX. 802.16m is the successor to 802.16e-2005 and is popularly named as Mobile WiMAX Release 2 or WirelessMAN-Advanced.It has been already approved by ITU-R as an IMT-Advanced technology.

802.16m Features

Practically with 4 by 2 MIMO, 20MHz bandwidth and TDD topology 802.16m support 120 MBPS(Mbits per sec) in the downlink and 60MBPS in the uplink per site simultaneously.

802.16m will work in TDD and also FDD mode, where there is a lot of spectrum globally. The channel bandwidths of 802.16m are targeted up to 20MHz and possibly 40MHz channels. In these higher channels OFDMA becomes extremely capable compare to other technologies, in terms of capacity and performance.

For a 20MHz sector the peak data rate in the downlink in 802.16e is 128MBPS, it will be in the order of 350mpbs in 802.16m. In the uplink, per sector it is 28MBPS in 802.16e, it will be 200MBPS in 802.16m.

Mobility in 802.16e is 60 to 120km/h, in 802.16m it will be up to 350km/h. That will make WiMAX technology more efficient for sensitive VoIP services, with latency of less than 10ms, and hand-off of 20ms. Following table mentions features of 802.16m(wimax advanced).

Specifications WiMAX Advanced Support
RF Carrier Frequency Under 6 GHz
Bandwidth 5 to 20 MHz
Antenna Configuration Downlink >= 2 T X 2 R
Uplink > = 1T X 2R
topology Full duplex FDD, Half duplex FDD, TDD

The difference between wimax and wimax advanced systems are as follows:
• Wimax(16d) does not support advanced antenna system concepts such as MIMO and beamforming, while wimax advanced support the same.
• Data rate and coverage can be achieved higher in wimax advanced compare to wimax.

802.16m References

802.16m-2011 standard can be downloaded from IEEE website.

Useful Links

Refer our page on 16d wimax physical layer which describes all the modules with modulation-code rate example.
Refer our page on WiMAX Base station Equipment Vendors.
Refer our page on WiMAX Subscriber station Equipment Vendors.
Refer our page on WiMAX System on Chip which mentions popular base station and subscriber station chip vendors as per wimax standard.
Refer our page on hardware manufacturers of wimax.
Refer our page on what are the functions of wimax.
Refer our page on comparison of fixed wimax and mobile wimax.
Refer our page on wimax system related terms.
Refer our page on WiMAX MAC layer or Layer 2 as per IEEE 802.16-2004 standard.
Refer our page on IEEE 802.16 family of standards.
Refer our page on OFDMA physical layer or Mobile wimax physical layer.
Refer our page on OFDM versus OFDMA which covers difference between OFDM and OFDMA concepts.

Links to WiMAX MAC Layer resources

WiMAX Ranging Procedure
WiMAX Bandwidth Request procedure
WiMAX Network Entry Procedure
WiMAX FCH header format
WiMAX TLV Format basics
WiMAX Timers
WiMAX Network Interface types
WiMAX QoS Classes

RF and Wireless Terminologies