Wireless chip maker Beceem Communications this week became one of the first manufacturers to ship a mobile WiMax digital base band and integrated radio chip set - MS120 - for handheld devices.

The chip set is based on currently available IEEE 802.16e mobile WiMax specifications. However, the IEEE has not yet ratified a mobile WiMax standard.

Beceem is also shipping a reference design kit for the WiMax modem, including host driver software.

Although the work by the IEEE on the mobile WiMax standard is not complete to date, Lars Johnsson, vice president of development for Beceem, said that when the standard is finalized, the MS120 chip set will be compatible.

"We guarantee it will be fully profile-compliant," said Johnsson.

Wild for WiMax

Mobile WiMax devices still must wait for the availability of WiMax networks.

Nevertheless, the entry into the market of mobile WiMax technology with a range equivalent to cellular and far superior performance is expected to raise some interesting issues down the road with the wireless carriers.

Using 10MHz of available spectrum, mobile WiMax is expected to have a 30Mbps peak rate with one kilometre range in densely populated areas and up to five kilometres in rural areas.

Although the carriers have a great deal of money invested in buying spectrum for deployment of their 3G networks, the WiMax chips would offer a competitive alternative. They also consume the same amount of power as cellular radios.

In addition, WiMax uses OFDM (Orthogonal Frequency Division Multiplexing) technology, which offers a number of other advantages, principally a lower power consumption rate than WiFi, making it attractive to the handset manufacturers.

OFDM has the ability to use minimum bandwidth when connecting to the network and only uses the highest speeds when there is real traffic. The system shuts off, into sleep mode, the moment the last packet arrives, according to Johnsson.

OFDM has other advantages as well. While a single user may never get peak performance due to latency in the IP network, OFDM can give the unused capacity to a different user.

While Johnsson believes the operators will face a choice between cellular and WiMax once mobile WiMax becomes readily available, one industry analyst sees it slightly differently.

Carriers create the future

Julie Ask, a senior analyst at Jupiter Research, said the carriers are committed to other technologies for their 3G networks. Sprint and Verizon are committed to EVDO (Evolution Data Only), while Cingular and T-Mobile are committed to HSDPA (High-Speed Downlink Packet Access).

However, carriers are evaluating technology for future 4G networks in the 2010 time frame.

"WiMax is a potential 4G technology. All the carriers are looking at it, but no decision has been made," said Ask.

Johnsson said once one carrier breaks ranks and uses WiMax instead of cellular, the others will quickly follow.