Johannesburg, 21 Feb 2005
The acceptance of wireless LANs based on the IEEE 802.11 or WiFi has been excellent, but with the South African telecommunications market opening itself to wireless technologies in the wide area, new innovations can be expected.
Andy Robb, a technology specialist at Duxbury Networking, looks at one of the main contenders in this field: WiMax.
With wireless technologies in the local area networking arena having been settled around the IEEE 802.11 standard, it is time to focus on activities in the wide area where there is still competition for the de facto technology standard.
This is fortuitous because, in SA, telecommunications regulations are relaxing to allow the use of wireless in wide area networking applications - and, what`s more, these links may now carry voice traffic in addition to data.
One of the main contenders is WiMax - or the Worldwide Interoperability for Microwave Access, as defined in IEEE 802.16 standard.
WiMax is the proposed standard for "fixed" wireless, last-mile technology and it is being championed by a vendor consortium led by Intel. Proxim and the WiMax Forum, which are promoting multi-vendor solutions that will result in lower cost products based on open standards.
Opposition for WiMax comes from WiFi, a local area network technology designed to add mobility to private wired LANs. While the two do indeed share some fundamental technical characteristics, they are approaching the wireless space from completely different perspectives.
Further, different design approaches will make it unlikely that the two will actually compete head-to-head - except by coincidence.
WiMax, unlike WiFi, was designed to deliver a metro area broadband wireless access service, and to provide a fixed location wireless Internet access service.
WiMax will offer faster data rates than those currently available in SA as it is capable of supporting up to 75Mbps of shared bandwidth, serving potentially hundreds of business subscribers within a cell size of up to 10km in diameter from the base station. WiMax will give each user access to around 512Kbps and 1Mbps of bandwidth.
And, unlike the wireless "last mile" services pioneered in the 1990s, users will not need line-of-sight alignment with a base station. This is because WiMax`s antennae will be integrated with a radio modem ensuring far greater versatility.
This concept is defined in the 802.16a standard first proposed in January 2003 that describes systems operating between 2GHz and 11GHz.
It should be noted that this standard superseded the original 802.16 version - released in December 2001 - which addressed systems operating in the 1 066GHz frequency band and which did require line-of-sight alignment to a base station.
WiMax is ideally targeted at the carrier market. In order to accommodate various carrier requirements around the world, WiMax systems can be configured for dual-channel (inbound/outbound) Frequency Division Duplex (FDD) or single channel Time Division Duplex (TDD) operation. In theory, WiMax technology should appeal to service providers.
Will WiMax prevail in the technology war? There are reasons why WiMax could fail. For example, in the US only a few spectrum holders own the licences that would be ideal for a WiMax deployment and it is unclear as to their level of interest in the technology.
However, of those that do, two have already made pre-standard products available to and are offering pre-standard broadband last-mile services to customers in Florida and to selected states in the north west regions of the US.
Some industry watchers have suggested that a portable or mobile version of WiMax might have a better chance of success. While future iterations of WiMax may well be more promising than the initial fixed version, it is difficult to forecast what the market will look like by the time a mobile or portable solution becomes available.
Whatever the outcome, enough interest in WiMax has been generated in recent months for three separate events to be hosted or planned which are dedicated to the technology.
In September and October 2004 the Emerging Broadband Wireless Technologies Summit was held in the US, as was WiMAXcon - which was held in conjunction with the Internet Telephony show in California.
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