In an announcement that should significantly expand broadband wireless deployments in North America, NextLink Communications Inc. (www.nextlink.com) said it has chosen Nortel Networks Inc. (www.nortelnetworks.com) to provide broadband wireless point-to-multipoint access equipment for its LMDS network.
NextLink has extensive U.S. and Canadian holdings in the LMDS portions of the spectrum, which ranges from 28gHz to 31gHz.
NextLink executives said the selection process had been lengthy, with a number of vendors that were still trying to meet the company's requirements for its networks. While most vendors have been able to deliver the required OC-3 (155mbps) bandwidth, there have been problems with stability in some systems, says Jeffrey Bader, director of deployment at NextLink. Others have not been able to transmit to multiple receive sites within one sector, a key requirement if LMDS providers are to serve multiple customers with flexible, bursty bandwidth.
Even though Nortel has gotten the nod from NextLink for deployment, it has delivered only the frequency-division multiple access (FDMA ) version, not the more-flexible and bandwidth-efficient version time-division multiple access (TDMA) version, of its system, Bader says. The TDMA system will soon go into lab testing at NextLink.
Despite the difficulties in obtaining multiple vendors for point-to-multipoint equipment, NextLink still expects to deploy LMDS networks in 25 cities by the end of the year 2000, says Steve Cooper, NextLink's executive vice president. The company is eagerly awaiting the TDMA technology, he adds, because "that will open a whole world of opportunity for us."
TDMA will allow NextLink to provide highly flexible bandwidth to customers. It can sell bandwidth for average usage, at 1 mbps to 2mbps, for example, but give customers the ability to burst to 10 mbps. This is critical for data traffic, which is highly variable in bandwidth. If pipes are fixed and a system is not dynamically flexible in allocating bandwidth among customers, much capacity is wasted.
Existing point-to-point systems with fixed pipes work well for large customers, but point-to-multipoint allows LMDS operators to serve small and medium-sized businesses as well.
Nortel joins two other vendors for the NextLink networks: Digital Microwave Corp. (www.dmcwave.com), which is providing point-to-point LMDS equipment, and Triton Network Systems (www.triton-network.com), which is providing consecutive-point LMDS equipment, sometimes called SONET extension systems.
