Mixed Signals
Any sufficiently advanced information is indistinguishable from noise
Saturday 13 September 2008, 11:52 PM
Birth of a new Wi-Fi
Hot news from Hawaii! The IEEE working group which brought 802.11n into the world is about to push that particular chick out of the nest and is already getting broody with the next egg. That egg is currently called VHT, for Very High Throughput, and is expected to have speeds up to 1Gbps, or even beyond, by using new frequency bands and some interesting new techniques.
One of those new frequency bands is 60GHz, which combines extremely high bandwidth possibilities with some very challenging physics. Nobody knows quite how this extremely high frequency band - which has a very short wavelength of 5 millimetres and is thus prone to bounce around alarmingly when it encounters anything of that sort of size and above - will work in the typical environment of a wireless LAN. But if it does, then VHT is talking about multiple parallel streams at 500Mbps.
It's not saying how this would work - whether the parallelisation happens in the time, frequency or code domains, or whether it's something else entirely. I'd guess (wildly) it was some advance on MIMO, with different channels differentiating themselves by propagation delay or multipath, not least because those teeny tiny wavelengths lend themselves to extremely complex antenna designs.
There may be another, even more intractable issue facing VHT than dull old physics, duller old industry conflicts (I do hope the lessons of 802.11n have been learned) or absolutely dullest issues of economics. A basic resource has been entirely exhausted - there are no more letters left to put after 802.11. From 802.11a (5GHz version of 802.11g) to 802.11z (extensions to Direct Link Setup (DLS)), they're all taken or reserved.
In the good old days of the CCITT, they solved the problems by appending bis or ter after a standard - V.22bis meant the second bite at V.22, V.22ter the third. But then, they were French. (And yes, I know there wasn't really a V.22ter.)
There is the danger, then, that the new standard will be known by some horrendous marketing tag - 802.11Hyperdrive Extended Grand Tourismo Edition of the Next Generation - or, worse, 802.11extreme. At least they're unlikely to adopt the Ubuntu habit of naming new developments as if they were cuddly toys.
One of those new frequency bands is 60GHz, which combines extremely high bandwidth possibilities with some very challenging physics. Nobody knows quite how this extremely high frequency band - which has a very short wavelength of 5 millimetres and is thus prone to bounce around alarmingly when it encounters anything of that sort of size and above - will work in the typical environment of a wireless LAN. But if it does, then VHT is talking about multiple parallel streams at 500Mbps.
It's not saying how this would work - whether the parallelisation happens in the time, frequency or code domains, or whether it's something else entirely. I'd guess (wildly) it was some advance on MIMO, with different channels differentiating themselves by propagation delay or multipath, not least because those teeny tiny wavelengths lend themselves to extremely complex antenna designs.
There may be another, even more intractable issue facing VHT than dull old physics, duller old industry conflicts (I do hope the lessons of 802.11n have been learned) or absolutely dullest issues of economics. A basic resource has been entirely exhausted - there are no more letters left to put after 802.11. From 802.11a (5GHz version of 802.11g) to 802.11z (extensions to Direct Link Setup (DLS)), they're all taken or reserved.
In the good old days of the CCITT, they solved the problems by appending bis or ter after a standard - V.22bis meant the second bite at V.22, V.22ter the third. But then, they were French. (And yes, I know there wasn't really a V.22ter.)
There is the danger, then, that the new standard will be known by some horrendous marketing tag - 802.11Hyperdrive Extended Grand Tourismo Edition of the Next Generation - or, worse, 802.11extreme. At least they're unlikely to adopt the Ubuntu habit of naming new developments as if they were cuddly toys.
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