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The terminology kills me: Nortel says that a provider in the UK will use its equipment to deploy WiMax service in the 3.5 GHz band in the UK. But the licenses for that operator allow only fixed use. Rather than use the 802.16-2004 spec which offers fixed-only profiles, Nortel says its partner will use 802.16-2005, typically referred to as mobile WiMax—but which has fixed, nomadic, and mobile uses. (The band is owned by Pipex, which ZDNet reports said it wasn’t working with Nortel.)
There’s still debate over a dedicated band that would allow mobile WiMax, with 2.5 to 2.7 GHz under consideration. 3G operators naturally want 3G-related standards to be the only ones permissible in that band.
Posted by Glennf at October 12, 2006 8:27 PM
Its true that 802.16-2004 does include an uplink 2048 FFT OFDMA air interface option, but the "fixed WiMAX" subset of 802.16-2004 only specifies the 256 FFT OFDM air interface. Manufacturers that have "fixed WiMAX" 256 OFDM products to sell tend to blur the differences between the different flavors of WiMAX while manufacturers that plan to have 802.16-2005 "mobile WiMAX" products in the future emphasize the differences. I predict that only 802.16-2005 based TDD 5ms frame 512 or 1024 FFT mobile WiMAX survives to be simply called WiMAX.
Biased but useful info on differences between "fixed WiMAX" and "mobile WiMAX" follows.
Posted by: George B at October 20, 2006 10:01 AM
Actually the 802.16-2004 also includes the same UL functionality described in the previous comment - called "sub-channelization" - as an option.
The 802.16e-2005 standard includes many improvements to the standard, including better security, smart antennas, and OFDMA (also in DL), which make it a superior standard also for fixed-wireless applications.
[Editor's note: I should distinguish that while -2004 has OFDM, it doesn't allow flexibility in provisioning each subchannel over either time or frequency domains (TDD or FDD). With OFDMA and -2005, different subcarriers can be dynamically scheduled to be uplinks or downlinks across either time or frequency, allowing for more efficient and more specific provisioning.--gf]
Posted by: jno at October 20, 2006 1:14 AM
Ignore the confusing "fixed WiMAX" vs. "mobile WiMAX" marketing terms. "Mobile WiMAX" 802.16-2005 (802.16e) should be less expensive to deploy for consumer fixed networks than "fixed WiMAX" 802.16-2004 (802.16d). 802.16-2005 tends to allow the use of indoor self-installed modems vs. outdoor antennas for 802.16-2004. For 256 FFT OFDM 802.16-2004 the subscriber station must use all subcarriers when transmitting and uplink capacity is shared by dividing the channel into short bursts in time. The 802.16-2005 scalable OFDMA air interface allows each subscriber stations to use a subset of the available subcarriers while other users are using different subcarriers. Sending the same information using less bandwidth stretched out over a longer period of time allows the subscriber station to either transmit less power (less expensive RF components) or use a much smaller antenna to achieve the same SNR at the base station receiver.
Posted by: George B at October 16, 2006 11:45 AM