Saturday, August 11, 2007

Whither WiMAX?

Written by John Mayberry

Preview for Systems Contractor News Magazine
August, 2007

The United States has fallen significantly behind the rest of the world in data bandwidth, both wired and wireless. We now rank 15th in fat-wired economies worldwide according to the CWA in the hardwired world. Our median Internet download speed is 2 Mbps while Japan leads the world at 61 Mps. Our domestic DSL and cable provider services are not competitive on the world market.

It’s with this thought in mind that the FCC is auctioning off the 700 MHz spectrum in 2008, where a wireless competitor to cable and DSL is envisioned called WiMAX. Most of the big players from cable and Internet are eyeing the auction with great interest. The bandwidth, being wrested from broadcasters moving to digital, is ideal for penetrating buildings, which is why it is currently being used by UHF television channels 52 through 69.

Entry cost for the auction? You eBay bidders should note the reserve price is $4.6 billion. Make sure your PayPal account is ready.

Those of you using UHF wireless microphones may likely be using those frequencies right now. The carrier for many wireless mic systems lies right in the middle of that bandwidth. On July 31st the FCC’s office of Engineering and Technology evaluated two prototype wireless mic prototypes systems designed to use television white space instead of the 700 MHz bandwidth.

The July tests failed; mice and men are currently being led astray without an acceptable alternative. One doubts whether wireless mic operability concerns will hold up the auction though. There’s also an unresolved battle with the satellite folks over the spectrum.
WiMAX (Worldwide Interoperability for Microwave Access) should not to be confused with WiFi. WiMAX is aimed to provide wireless data over multiple methods, including full mobile and fixed applications over a standardized and interoperable platform to provide an alternative to DSL and cable for the “last mile”.
The bandwidth and reach of WiMAX make it suitable for connecting Wi-Fi hotspots to each other, an alternative to cable and DSL, high speed data and telecommunications applications, a secondary backup, and nomadic connectivity. Hopefully it will remain a competitive arena with multiple players to keep pricing low.

WiMAX subscriber units are available in both indoor and outdoor versions from several manufacturers. Self-install indoor units are convenient, but radio losses mean that the subscriber must be significantly closer to the WiMAX base station than with professionally installed external units. Indoor units are comparable in size to a cable modem or DSL modem. Outdoor units are roughly the size of a laptop PC, and their installation is comparable to a residential satellite dish.

Some cellular companies are evaluating WiMAX as a means of increasing bandwidth for a variety of data-intensive applications; Sprint Nextel announced in mid-2006 that it would invest about US$ 3 billion in a WiMAX technology build out over the next few years.
WiMAX differs from WiFi primarily in how they connect and how efficiently they use the spectrum. The WiFi wireless access point we’re familiar with at Starbucks croaks after a few VOIP or IPTV connections connect due to the way interruptions are handled. WiMAX is a longer range system, roughly comparable in range to a cell phone, where WiFi is more comparable to a cordless phone.

WiMAX maximum capabilities are 70 Mbit/s and/or a range of 30 miles. Somewhat analogous to Heisenberg’s thinking, you will get one or the other but certainly not both at the same time. In urban environments it’s believed to max out at 10 Mbit/second over one mile.

WiMAX uses a scheduling algorithm which allocated slots after initial entry into a network. The slot bandwidth can enlarge or contract, but remains assigned until disconnected. Quality of Service parameters can be automatically balanced.

Due to the ease and low cost with which Wi-Fi can be deployed, it is sometimes used to provide Internet access to third parties within a single room or building available to the provider, sometimes informally, and sometimes as part of a business relationship. For example, many coffee shops, hotels, and transportation hubs contain Wi-Fi access points providing access to the Internet for patrons.

All of the WiMAX effort may amount to a hill of beans at this point. Japan’s NTT DoCoMo has already begun testing a new cellular network capable of downloading speeds up to 300 Mbits/second. Completion of a Japanese nationwide network is scheduled for 2009, three years before WiMAX deployment would likely be completed in the USA.

It would appear that we’re destined to stay in 15th place for quite some time. There are some bright spots on the horizon. US telecom carriers currently plan on spending $70 billion on system upgrades over the next few years. Verizon alone is spending $18 billion of that on FiOS, a venture to bring fiber to the home and bypassing the limitations of WiMAX altogether.

Having a market driven telecommunications infrastructure has its limitations indeed. WiMAX represents an improvement, but not a panacea. Yawn.