The 5 Ws of WiMAX

What

Though fixed wireless technology is not new, a major interoperability standard, Wireless Interoperability for Microwave Access (WiMAX), is relatively new in North America. WiMAX lets base stations, customer premise equipment and modem cards manufactured by different vendors operate on the same network. It is based on some of the 802.16 standards stipulated by the Institute of Electrical and Electronics Engineers (IEEE) Wireless Municipal Area Networks Working Group for Broadband Wireless Access.

The Fixed WiMAX standard is based on IEEE 802.16 2004, while Mobile WiMAX is based on the IEEE 802.16e-2005 standard.

The WiMAX Forum, which certifies products for interoperability, says it has “developed profiles” for the 2.3, 2.5 and 3.5 GHz frequency ranges.

Although it has been compared to Wi-Fi, the capabilities are much different. Whereas Wi-Fi has a range of 100 metres and requires line of sight, WiMAX is intended to provide coverage at much greater ranges, without the requirement for line of sight, making it better suited for municipal networks and as an access technology for telecommunications carriers. The exact range depends on factors such as interference from buildings and terrain.

Products certified by the WiMAX Forum are supposed to provide a range of up to 5 km.

“We have seen (ranges) in excess of 10 km but I don’t think you’ll get much more than 10 or 15, honestly,” said Ted Chislett, president of Primus Telecommunications Canada Inc. which is conducting trials in Hamilton and suburban Toronto. “As you get further out, you’ll get slower speeds.”

Like Wi-Fi, WiMAX is designed to provide broadband connections. The WiMAX Forum, which tests equipment for interoperability, states “certified systems can be expected to deliver capacity of up to 40 Mbps per channel.”

But individual users won’t get this much bandwidth, said Monica Paolini, president of Senza Fili Consulting LLC of Sammamish, Wash.

“It will be split among the users that happen to be in the coverage area of the sector,” she said.

On its Web site, Primus says its trial service can provide up to 1 Megabits pers second (Mbps) downstream and 128 Kilobits per second (Kbps) upstream. But Chislett says he hopes users can get much more.

“I would hope that we could get a couple of (Mbps) down and almost (1 Mbps) up,” he said.

Who

The 802.16 standards are actually written by the IEEE, not the WiMAX Forum. The WiMAX Forum certifies the products and defines system profiles. A piece of equipment that is certified by the WiMAX Forum means it complies with IEEE 802.16 and is interoperable with equipment from other vendors that are WiMAX Forum-Certified.