Sprint Nextel and a smaller WiMax hopeful, Covad Wireless, each moved closer to offering commercial service on Thursday.

Samsung Electronics equipment used on Sprint's mobile WiMax trial network in the Baltimore-Washington, D.C., area has met the carrier's criteria for commercial acceptance, along with two client devices. Covad announced the successful completion of a lab test and field trial of its planned fixed WiMax service for businesses in the San Francisco Bay Area.

The twin announcements highlighted the potential impact of WiMax on both the fixed-wireless and mobile data worlds. WiMax is being widely adopted by providers of fixed-wireless broadband and is expected to slash the cost of those networks. In the mobile data sweepstakes, different WiMax technology is getting a head start on the LTE (Long-Term Evolution) cellular standard, which is still being developed but has potentially a much larger customer base among established mobile operators.

Sprint is gearing up for a commercial launch later this year after some delays. The ambitious network it plans, spanning the U.S., will be operated by a joint venture with Clearwire, cable companies and other partners as soon as that company is created. Sprint built its first two test networks in the Washington, D.C., area, with Samsung gear, and in Chicago with Motorola products.

The Washington-area Samsung network has met all technical requirements for commercial Sprint service, including overall performance, handoff performance and handoff delay, Sprint said Thursday. A number of client devices, including Samsung's E100 PC Card modem and Q1 Ultra Premium Mobile PC, a ZyXel modem and a Nokia Internet tablet, have also met Sprint's requirements, said Sprint spokesman John Polivka.

The carrier is still testing the Motorola network in Chicago on the same standards, Polivka said. Sprint's evaluation is specific to its own network and is in addition to certifications by the WiMax Forum. In addition to clearing the technology, Sprint needs to set up adequate wired backhaul capacity and set up back-office systems such as user authentication, privacy, security and billing, Polivka said.

While trials continue on the first two networks, Sprint is building infrastructure in other cities, some of which will be supplied by Nokia Siemens Networks, Polivka said. Sprint conservatively estimates the service will deliver 2M bps (bits per second) to 4M bps on average, with peaks as high as 10M bps, he said.

Covad Wireless, a division of competitive Internet service provider Covad Communications, said it has decided to move forward with fixed WiMax later this year based on results from the Bay Area trial. The test, using infrastructure from Axxcelera Broadband Wireless, showed a capability to deliver 8M bps (bits per second) both upstream and downstream. The network had less than 1 percent packet loss and less than 50 milliseconds of latency, the service provider said. In its commercial service, called "Super-T," Covad expects to deliver as much as 6M bps to each fixed modem.

The ISP will now start deploying WiMax at existing base-station locations in Los Angeles, Orange County and the Bay Area. It chose Axxcelera, a startup in Santa Barbara, California, because testing proved the vendor's WiMax gear worked best with Covad's current pre-WiMax wireless gear.

Covad Wireless already offers data service to businesses at speeds as high as 45M bps but believes it can deliver a greater variety of services to a broader range of customers with WiMax. Covad Wireless serves about 4,000 small and medium-size businesses around San Francisco, Los Angeles, Chicago and Las Vegas.