The appeal of Wi-Fi is simple: no more Ethernet cables. Freedom from the shackles of copper wire is not just convenient, it's downright liberating. But walk into an enterprise conference room, and what do you see? The Cat5 Ethernet cables may be gone, but step carefully, lest you catch your shoes on someone's power cable snaking its way across the floor. So much for liberation.
I recently moved into a newly renovated building on the campus of Syracuse University. Given my interest in wireless networking, I lobbied hard for a high-capacity, dual-band WLAN infrastructure. Coupled with a generous helping of conference rooms, both large and small, the wireless infrastructure is a critical element in our effort to encourage collaboration. Although the environment has been well received by students, faculty and staff, everyone has one major complaint: not enough power outlets. Despite marketing claims of leading notebook computer manufacturers, most of our wireless-intensive users can't make it through a typical meeting without plugging their power brick into the wall.
Limited notebook battery life is often viewed as an inconvenience, but the nomadic nature of notebook users makes the situation tolerable. For users of emerging Wi-Fi-enabled VoIP and smartphones--so-called converged mobile devices--however, limited battery life is an absolute showstopper. That problem is getting some much-needed industry attention, most recently in the form of a new Power Save Certification from the Wi-Fi Alliance. This new element is part of the alliance's broader WMM (Wi-Fi Multimedia) program, which also addresses key issues related to quality of service.
Though the original 802.11 standard included provisions for conserving battery power, the system has not been widely adopted, in large part because its architecture results in a significant performance hit and additional network overhead. In addition, legacy power-savings mode is controlled by network interface drivers rather than by applications, a one-size-fits-none approach.
For converged devices supporting real-time voice applications with strict latency requirements, legacy 802.11 power-savings technology simply isn't workable.
To function properly, WMM Power Save needs to be implemented on APs (access points), in wireless device drivers and within applications running on those devices. Wireless stations and APs negotiate power save when the station associates with the AP. The system leverages the priority queues defined in WMM and 802.11e while also maintaining backward compatibility with legacy 802.11 power-savings mode.
Because WMM Power Save requires tight integration between applications and wireless drivers, it is likely that initial applications will focus on application-specific mobile devices, especially VoIP phones. The Wi-Fi Alliance suggests that such devices will realize enhanced power efficiency of between 15 and 40 percent. However, to be successful, this "standard" will need to be broadly supported by chipset and AP manufacturers. The Wi-Fi Alliance is off to a good start in that regard, with a number of products already certified. The list includes AP reference designs from Atheros and Broadcom, Cisco's Model
1231 abg AP and several client radio modules from Broadcom, Conexant, Ralink and Winbond.
Purists might argue that this is yet another example of an industry association encroaching on turf that traditionally has been the domain of standards bodies.
To a certain extent, that's true. But as basic 802.11 functionality becomes a commodity in the market, you don't really need the Wi-Fi Certified stamp of approval to ensure basic interoperability.
Extending beyond the basics has never been an easy task for the IEEE, especially when issues relate to application-layer functionality. The Wi-Fi Alliance continues to assert its relevance by striving to meet the needs of its membership, including the many companies that see voice as a compelling WLAN application. By making WMM Power Save an optional element of the certification, the alliance isn't forcing companies to adopt this technology. But by offering such a certification, the alliance is advancing important capabilities that will provide enterprise IT professionals with more choices. That's good for the industry.
For more analysis and opinion from Dave Molta.
http://update.networkcomputing.com/cgi-bin4/DM/y/esc70GRsYM0G6v0DCse0GA
Plus, here's an update from Peter Rysavy on his column last week about Linksys' popular WRT54G wireless router.
Since our story last week about Cisco/Linksys changing the WRT54G Wireless-G Broadband Router from a Linux-based system to a WxWorks-based system, Linksys contacted us to say it will maintain the Linux-based system under a new model number of WRT54GL. The company's statement was, "We are honored by the overwhelming loyalty of Linux users to our products, and this dedicated SKU is our way of saying thank you for the support this community has given to us and our products."
We are pleased that the Linux-based version (current equivalent to WRT54G v4) will remain available for those who desire it. However, we're still not happy about the apparent quality and performance issues of the currently shipping WRT54G. Also, it's a little unusual to create a new SKU for an existing product and to use the old SKU for, effectively, a new version of the product. However, it does mean that Linksys/Cisco can direct its huge volumes of this product's sales, estimated at hundreds of thousands per month, to the version that costs the company less to manufacture. Hopefully, Linksys/Cisco can quickly address the problems with this version so that these hundreds of thousands of users don't have the unfortunate experience I had.
