Having a higher-performing network will enable these sorts of options. But this also presents challenges for electronic designers who must now package wireless solutions in different form factors to support these non-PC devices, and must take into account different battery and power consumption profiles that these devices make use of.
Another application for higher-speed wireless networks has to do with network-attached storage. As prices drop and storage needs increase, these units are being pressed into service for video servers and digital music. Network attached storage devices will require reliable, high-bandwidth connections to stream pre-recorded high-definition TV shows, music videos and full-length feature films to televisions and computers throughout the house.
One final lesson is to incorporate the multiple antenna designs that have been developed for enterprise-class access points into the consumer-grade wireless networks. Many of the 802.11g products came to market with multiple antenna designs, and of course each vendor uses a different set of electronics and designs for how these multiple arrays are packaged.
The idea is that the more antennas, the longer the range that your radios can send and receive signals. While that is true in an ideal situation where a single access point is talking to multiple clients scattered around the landscape, the real world is a much harsher RF environment with multiple access points and interference from lots of radio emitters like microwave ovens, cordless phones, and older Wi-Fi networks.
Lesson 8: Multiple antennas matter.
In the quest for higher data rates, having more than one antenna and more than one radio stream matters for delivering better throughput. The 802.11n draft is the first IEEE standard to support these innovations.
Despite all of these history lessons, the industry still hasn't finalized the 802.11n standard. It will be at least the beginning of 2007 before it is ratified.
Why so long? There are several issues. First, the specification has an unprecedented collection of new technologies, with more variety and depth than in any previous 802.11 standard.
Second, the wireless market has expanded greatly over the past several years: it is hard to find a laptop sold today without built-in Wi-Fi features, and users have come to expect wireless access at their hotels, airports and in major downtown business districts.
The increased market means more engineers present at the various working group meetings and the longer it takes to reach consensus. This was one of the reasons Broadcom and others took a separate group of experts outside of the IEEE process to chart a common ground for the 802.11n standard.
Third, the diversity of new wireless products beyond just PCs means that new test plans and processes have to be put into place to certify them for the new standard.
Finally, there is the issue of supporting earlier 802.11 standards and making sure that new products play well with older ones. This increases the testing and certification process as well. One of the things the industry is addressing in the 802.11n process is to ensure that new innovation doesn't harm existing 802.11 networks.
The introduction in 2003 of products based on 802.11g specifications provided large numbers of consumers with the benefits of wireless networking for the first time. With its ability to enable sharing of Internet connections and printers without installation of new cables throughout the home, Wi-Fi has emerged as the fastest growing technology for home data networks. And with the coming of 802.11n, more capable networks are enabled with higher performance and richer support of multimedia applications.
Table 1- Summary of Different Wireless Networking Approaches
Notes: (1) OFDM - Orthogonal Frequency Division Multiplexing, "+" indicates improvements that are part of 11n draft standards with wider bandwidth and higher code rates; DSSS = Direct-Sequence Spread Spectrum; CCK = Complementary Code Keying.
About the author
David Strom is an author, consultant, podcaster, and speaker on a
wide variety of networking and communications topics. He was the founding editor-in-chief for Network Computing and created the DesignLine series of sites for CMP Media. He can be reached at [email protected] and is based in St Louis.
