By the end of 2010, users in more than 80 US cities may be able to ditch their cable modems, T1 setups and DSL lines - and the Wi-Fi routers that go with them - in favour of WiMax broadband wireless technology.

Wait, haven't we heard that before? WiMax (Worldwide Interoperability for Microwave Access) has been promised "any day now" for years, but WiMax vendors such as Clearwire Communications have suffered numerous delays in rolling out services. A recent ramp-up in Clearwire deployments bodes well for WiMax, but it may not have the chance to fully get off the ground before a competing technology called Long-Term Evolution (LTE) does it in.

Craig Mathias, principal analyst at Farpoint Group and a Computerworld columnist, sees WiMax taking a minority stake in the wireless broadband future. "LTE will eventually be a combined broadband voice/data solution that can do everything that WiMax can and more," he said via email.

Mathias believes that LTE could get up to 80% of the global market share in future cellular installations. "This leaves WiMax with a potential market share that cannot exceed 20% - but that's still a huge number, assuming 4 billion users around 2020 or so," he said. "You do the math. The opportunity is nothing to sneeze at."

The promise of WiMax

Clearwire and partners like Intel, Comcast, Time Warner Cable and Cisco want to change the last networking mile in the same way that Wi-Fi changed the last 100 feet of networking: by complementing or possibly replacing the existing technologies.

WiMax can cover up to 31 square miles instead of the few hundred square feet per access point provided by the more familiar 802.11g and 802.11n Wi-Fi technologies. In theory, WiMax can also deliver more than 75Mbit/sec. data-transfer speeds. In practice, it doesn't have either that range or that speed. But with real-world speeds of up to 9Mbit/sec, it's about as fast as today's standard 802.11g (though not as fast as 802.11n), and it offers far greater range than any Wi-Fi technology.

Arthur Giftakis, vice president of engineering at Towerstream, a national WiMax provider for businesses, believes WiMax will deliver "high-speed mobile services that consumers and business users alike are demanding more and more," such as the ability to watch sports highlights on a laptop on the train or download apps on a handheld device. "WiMax will enable you to do those things faster than previous technologies," he said in an email interview.

WiMax incorporates quality of service technologies for prioritising network traffic, and that is particularly important for voice-over-IP and video applications, noted Joel Payne, vice president of engineering and operations at Sparkplug, a national Internet service provider serving the business market.

In contrast, Wi-Fi access points can be overwhelmed by multiple clients demanding simultaneous access. "The WiMax protocol will be important for applications that require a lot of data to be transmitted on time, and to decrease packet loss and latency," said Payne via email.