Tuesday, October 28, 2008

XOHM, XOHM's Got The Range

Sprint's XOHM (say zome, like home) wireless broadband service is off and running in Baltimore. This is the start of the long anticipated deployment of WiMAX as the next generation of high speed Internet service. If Sprint is able to realize its 4G dream, WiFi hotspots may become a thing of the past. DSL? Cable? Who wants to be tethered by a wire when you can roam wirelessly, gloriously, free?

The dream is built on a new wireless technology that has been standardized for worldwide application in both fixed and mobile applications. WiMAX or Worldwide Interoperability for Microwave Access, offers coverage measured in dozens of miles and bandwidth that could extend to dozens of Mbps. Sprint's deployment offers 2-4 Mbps download and 0.5 to 1.5 Mbps upload. That's comparable to the majority of DSL, Cable broadband and even professional grade T1 and Ethernet connections.

WiMAX is often thought of as the big brother to WiFi. It's not a bad comparison if you are thinking in terms of laptop computers using wireless adaptors for broadband Internet access. WiFi's limitation is that it has a footprint pretty much limited to a single building. Drive away from the restaurant, home, or business office and your signal disappears. The best you can do is find another "hotspot" where you can resume operations.

WiMAX is meant to cover a town or major area of a city. It uses higher power signals on licensed frequencies. In Sprint's case it is their exclusive 2.5 GHz spectrum. The higher power levels of WiMAX transmissions allow their wireless signals to penetrate buildings and vehicles. OFDMA or Orthogonal Frequency Division Multiplexing Multiple Access modulation is resilient to service dropouts due to interference. MIMO or Multiple Input Multiple Output antenna technology also helps to improve system performance in the presence of multipath distortion that occurs when signals bounce off buildings in metro areas.

Sprint offers an XOHM base station modem for home or small office use. It looks a little like a high tech coffee brewer in shiny black. This device is self-contained with built-in antennas and Ethernet jack output. For mobile use, they have WiMAX aircards for PCMCIA slots or USB.

The direct competitor for WiMAX is 3G cellular broadband. Sprint also provides that service as EV-DO. You can order EV-DO service and air cards for nationwide access in most medium and major cities. Verizon offers a competing EV-DO service and AT&T has its own HSDPA broadband service, popularized by the Apple iPhone 3G.

XOHM is on its way to Chicago and Washington DC, with systems planned for Dallas, Fort Worth, Boston, Providence and Philadelphia. Nationwide deployment should roll out in the years ahead, economics permitting. Who knows, in the future there may well be XOHM where the buffalo roam.

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