主题：【IT新闻】下一代Wi-Fi无线网络什么样 -- 802.11n简介 -- Highway

现在的Wi-Fi无线网络够快吗？108MB的Wireless设备现在已经非常普遍了。虽然在实际应用中Wi-Fi并没有这么快，但是对于广大用户来说，802.11a/b/g都已经More than enough了！

但是Wi-Fi的厂商并不这么想，这不，下一代的802.11n正在酝酿之中，可能在2006年就会正式出台。

802.11n将使用4G Hz左右的频率，比现在的2.4G快一倍。理论传输率为250MB，实际可用传输率也高达175MB(现在的802.11g实际可用传输率大概是25MB左右)。怎么样，够快吗？

我过，我倒是对这越来越快的Wireless有一点疑问：这种辐射对人体有害吗？大家都知道长时间使用手机会对大脑有损害，那么成天沐浴在这种高强的Digital信号中，我们的身体会受到损害吗?

[SIZE=4]802.11n: Next-Generation Wi-Fi[/SIZE]

Tired of pokey 802.11g wireless performance? September is slated to bring the first comprehensive look at what is likely to be the future of Wi-Fi: 802.11n. On the 13th, in Berlin, the Institute of Electrical and Electronics Engineers' (IEEE) 802.11n Task Group (TGn) will consider official proposals from numerous companies on what the specifications should be for the next-generation proposed standard, which promises speeds fast enough for an influx of new wireless applications. 

Although a ratified standard isn't expected until late 2006, the first wave of 802.11n products could arrive in the first quarter of 2005. "There's a good chance you'll see products by then that will be software upgradable to the 'n' standard," says Mary Cramer, strategic marketing manager at Agere Systems. In the past, users―and consumers with home networks in particular―have purchased early products well in advance of ratification of Wi-Fi standards. 

Agere Systems founded TGn Sync, one of the most powerful consortiums scheduled to deliver a proposal in Berlin. Cisco, Intel, Nokia, Nortel, Philips, Sony, and many more companies are members. 

TGn Sync's proposal gives a glimpse of how much impact the 802.11n standard may have on everything from digital homes to wireless offices. "We're focusing on 40-MHz channel bandwidth [double the current 20-MHz bandwidth], backward compatibility with 'a,' 'b' and 'g,' and shooting for a data rate of 250 Mbps with actual throughput of around 175 Mbps," says Cramer. To put that in perspective, 802.11g has a quoted data rate of 54 Mbps, but actual data rates are about half that. "Many of our member companies said we need speeds at least four times faster than current Wi-Fi performance to get people to upgrade," Cramer adds. 

Multiple-input, multiple-output (MIMO) antenna technology is key to how TGn Sync intends to boost speeds. "Many of the highest hopes for the standard rest on getting that in there," says Mike Wolf, senior analyst at Instat/MDR. Cramer adds that increased range may make it feasible for an 802.11n-based home to have just one inexpensive access point. 

So what applications might go on in an 'n' home? Cramer and Wolf point to multiple wireless video streams, many kinds of analog connections giving way to digital ones, and lickety-split large file downloads. It's not too early to keep an eye out for the next generation of Wi-Fi.