MMDS marches forward

MCI WorldCom last week officially launched its fixed wireless strategy with three market trials. With its Sprint merger pending, the carrier aims to perfect the technology for use in its high-speed data service offering.

The current trial markets - Jackson, Miss; Baton Rouge, La.; and Memphis - operate on the wireless communication service frequency of 2.3 GHz, which is similar to multichannel multipoint distribution service's (MMDS) 2.1 GHz and 2.5 to 2.7 GHz bands. Some trial participants have had commercial service from the previous spectrum owner WirelessOne, which MCI WorldCom acquired last year. The carrier does not plan to seek additional paying customers for these trials.

Each test is based on a similar architecture using a supercell, which can reach farther than 30 miles, situated on an existing building or tower. Inside the supercell resides a wireless cable modem platform, provided by Hybrid Networks. The company also is supplying the radio technology. California Amplifiers is providing the antennas.

Hybrid's S2000 wireless broadband access system offers 2 MHz sub-channels used with different subscriber loadings. With sub-channels, the system mitigates interference between transmitters and lets carriers create adaptable sectors in large installations. The technology also can tune to the exact wireless frequencies, making it easier to test new markets.

"The key is that we are past the development stage of a two-way wireless system," said Stephen Grzelak, director of sales in the East for Hybrid. "The exciting thing is that our system will provide flexibility in terms of what frequency MCI [WorldCom] will be using to build a two-way wireless system."

For now, participants are using the carrier's WarpOne and Warp 310 kb/s wireless broadband services.

As the carrier conducts more trials, the architecture could change, said Jonathan Mapes, chief technology officer for MCI WorldCom Wireless Solutions. Previously, this type of wireless cable platform involved large infrastructure such as huge transmitters and single-rack radios.

"Companies can use different backhaul technology according to what is needed in a specific market," Mapes said. "We want to provide a rich service for our customers, and we need options to do it."

The technology could evolve, providing carriers with two dominant configurations. One, similar to MCI WorldCom's current trial markets, could include a supercell design. The second would be applicable in a larger market, which could be served by a series of minihubs that are lower to the ground and smaller. "What we do on a small scale, we can learn to replicated on a larger scale," Mapes said.

"Major players like Sprint and MCI [WorldCom] have given this spectrum real value. They have a competitive advantage over other operators, which is a key part of the equation that was missing from the industry years ago," said Robert Furniss, director of product line management for Hybrid.

MCI WorldCom now is focused on the current trials, which are expected to continue for about two months."We have to make sure to do it right before we rollout services," Mapes said, noting that in Jackson, the service reaches customers as far as 29 miles outside the city.

In Baton Rouge, the carrier is considering expanding services to the business market.

MCI WorldCom will hold additional trials in several larger markets in early 2000, though not until the FCC grants licensing approval. MCI WorldCom has yet to disclose definite plans, but it likely will work with ADC Telecommunications in the Boston market and Motorola and Cisco Systems in Dallas.

Sprint, which also works with Hybrid and California Amplifiers, has had MMDS trials going since spring 1999 in Detroit, Phoenix and San Francisco.