Wireless Networking Speeds of 540 Mbps w/ 802.11n 225
GuitarNeophyte writes "The Register reports three of the major players in forming the 802.11n standard have agreed to join forces in order to bring the new protocol into reality. Speculation states that the speeds using the new standard could be in the 540Mbps area! "Rather than see the 802.11n standards-setting process become deadlocked, as has happened in other cases, most notably ultrawideband, TGn Sync and WWiSE have clearly realized it makes more sense to work together than against each other.""
n? (Score:2, Interesting)
Network Burn (Score:3, Interesting)
Re:I'll believe it when I see it. (Score:3, Interesting)
If the pattern holds true to the same as 802.11g, we will see 200mbit at close range, and 100mbit at normal range.
In other words they will claim 540mbit but we'll get 100mbit wired performance.
The problem is that even 540mbit is not enough because a wireless network is like a hub, not a switch. All bandwidth is shared, and it is half duplex; only one person can send at a time on the entire wireless network. 540mbit sounds amazing, but even at the 200mbit you get at close range, if you have ten people on the network, each can only get 20mbit if they all transfer at the same time. I imagine collisions would further reduce that. And cut some more off for upstream usage.
Re:In the past... (Score:3, Interesting)
Channels and international compatibility
802.11b and 802.11g divide the spectrum into 14 overlapping, staggered channels whose center frequencies are 5 megahertz (MHz) apart. It is common to hear that channels 1, 6 and 11 (and, if available in the regulatory domain, channel 14) do not overlap and those channels (or other sets with similar gaps) can be used such that multiple networks can operate in close proximity without interfering with each other, but this statement is somewhat over-simplified. The 802.11b and 802.11g standards do not specify the width of a channel. Rather, they specify the center frequency of the channel and a spectral mask for that channel. The spectral mask for 802.11b requires that the signal be at least 30 dB down from its peak energy at ±11 MHz from the center frequency and at least 50 dB down from its peak energy at ±22 MHz from the center frequency.
Since the spectral mask only defines power output restrictions up to ±22 MHz from the center frequency, some people assume that the channel's energy doesn't extend any further than that, but in reality, it does. In fact, if the transmitter is sufficiently powerful, the signal can be quite strong even beyond the ±22 MHz point. Therefore, it is incorrect to say that channels 1, 6, and 11 do not overlap. It is more correct to say that, given the separation between channels 1, 6, and 11, the signal on any channel should be sufficiently attenuated to minimally interfere with a transmitter on any other channel. But this is not universally true. For example, a powerful transmitter on channel 1 can easily overwhelm a weaker transmitter on e.g. channel 6. In one lab test, throughput on a file transfer on channel 11 decreased slightly when a similar transfer began on channel 1, indicating that even channels 1 and 11 can interfere with each other a little bit.
Although the statement that channels 1, 6, and 11 are "non-overlapping" is incomplete, the 1, 6, 11 guideline has merit. If transmitters are closer together than channels 1, 6, and 11 (e.g. 1, 4, 7, and 10), overlap between the channels will probably cause unacceptable degradation of signal quality and throughput.