Faster WiMax on the Way
The standards body put together a work plan for the new specification, dubbed 802.16m, at its January session in London. Vendor sources here at the 3GSM show, however, have expressed some skepticism about the speed with the work can be completed (the end of 2009 is being mooted as a baked date) and the chances of maintaining backwards compatibility with mobile 802.16 technology.
The IEEE says it wants to develop a "competitive" and "significantly improved" radio access technology that is "compliant with the International Telecommunication Union (ITU) R/IMT advanced requirements for 4G" while maintaining interoperability with the mobile WiMax kit that is just starting to arrive on the market. This will mean up to 1-Gbit/s fixed and 100-Mbit/s data transfer rates and "improved broadcast and multicast and VOIP performance and capacity," achieved through a number of technical tweaks to the air interface.
The muscle behind 802.16m will be multiple-input/multiple-output (MIMO) antenna technology on top of an OFDM-based radio system just like the upcoming "Wave 2" mobile WiMax products being plotted by several silicon vendors. The Wave 2 profile, which is being championed by Sprint Corp. (NYSE: S), is expected to achieve mobile speeds of around 5 Mbit/s by using a two-by-two antenna array. 802.16m could up those speeds, in part, by using larger antenna arrays.
Insiders suggest that the latest work on the 802.16 and WiMax technologies is increasingly being driven by the wants and desires of carriers plotting next-generation mobile networks that will combine VOIP services with a hefty dose of whiz-bang multimedia services -- such as IPTV, streaming video, and fast music downloads. This is different from the initial work on fixed and mobile WiMax, which was pushed heavily by chipset and infrastructure vendors. (See Working for the MAN.)
Some folks worry that carriers have unrealistic expectations on how fast new WiMax profiles and interfaces can be developed. "They just walk in, snap their fingers, and expect it to happen," one industry source told us on the show floor yesterday. After all, it took several years for the IEEE to arrive at a satisfactory fixed broadband wireless specification in the form of 802.16d and even longer for the WiMAX Forum to certify interoperability between products using the technology. (See WiMax Spec Ratified.)
What's really provoking the disbelieving chuckles here at the show, however, is the requirement for backwards capability between current and future 802.16e offerings and the planned advanced air interface. Such disbelief is not that surprising when you think back to the recent interoperability issues between 802.16d and 802.16e. (See WiMax: A Spec Divided.)
Nonetheless -- despite possible future bumps in the road for 802.16m -- the move to develop a faster spec comes even before products based on the current mobile WiMax specification are generally available. This once again indicates the way certain parts of the industry are trying to aggressively push WiMax forward as the only the possible choice for future 4G networks.
— Dan Jones, Site Editor, Unstrung