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The lowly antenna gets some respect

By Craig J. Mathias
November 9, 2006 12:00 PM ET

This technique can be a bit controversial when it comes to wireless LAN access points. After all, isn't it simpler to just plug the APs into spare RJ45 connector and avoid the whole installation effort altogether? While this approach can work well in most open-office enterprises, there are other venues -- in fact, any that have fundamentally public access -- where it just isn't appropriate to leave an AP out and exposed. And, assuming that one wants to bring cellular or other wireless coverage to these areas as well, a DAS can make a lot of sense.

The most visible DAS suppliers include InnerWireless, LGC Wireless and MobileAccess. Each has a different approach to implementing a DAS, and there are options. One that attracts a good deal of attention is leaky coax, which is just that -- a coaxial cable that quite literally "leaks" radio energy along its length. (For an example, see Trilogy Communications' wireless products.) While these can be useful for venues such as subway tunnels and elevator shafts, they are not in general very efficient and actually make RF planning more difficult in systems that use discrete channels -- and that's most modern systems. Nonetheless, leaky coax can be quite valuable in otherwise difficult-to-provision applications.

Looking ahead, I'm expecting that the rate of innovation in antennas will match that of the rest of the wireless industry. While the antenna is, again, conceptually simple and usually just a piece of metal in a particular shape and size, it is an integral component in a complex machine. The proper choice of antenna by product designers can be the determining factor in whether a call goes through, or you could be left wondering once again why wireless isn't as reliable as it could be.

Craig J. Mathias is a principal at Farpoint Group, an advisory firm specializing in wireless networking and mobile computing. He can be reached at craig@farpointgroup.com.

Read more about Mobile/Wireless in Computerworld's Mobile/Wireless Topic Center.



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