WiMax threatens DOD radars, officials say

ANNAPOLIS, Md. -- The wireless industry views WiMax as the next big thing, a technology with great promise to deliver broadband to homes and offices less expensively than wired connections. But proliferation of the new commercial long-range wireless systems could cause problems for Defense Department radar systems, which operate in the same frequency bands, top DOD officials said at the ACEA DOD Spectrum Summit Dec. 6.White House and National Telecommunications and Information Administration (NTIA) officials said commercial wireless systems present opportunities and challenges for DOD, adding that the United States needs to find ways to share frequencies.Ron Jost, deputy assistant secretary of Defense for command, control, communications, space and spectrum in the Office of the Assistant Secretary of Defense for Networks and Information Integration, agreed that DOD needs to find ways for its systems to coexist and share spectrum with commercial products but added that such an approach is much more difficult internationally.Badri Younes, DOD’s director of spectrum management, said the de facto international WiMax frequencies are at 3.5 GHz, in the middle of a swath of spectrum used by DOD land-based, shipboard and aircraft radar systems. At home, the Federal Communications Commission has allocated spectrum between 3.65 and 3.70 GHz on an unlicensed basis to wireless Internet service providers for broadband services.John Kneuer, assistant secretary of commerce for communications and information and NTIA administrator, said that although new technologies such as WiMax put pressure on the DOD spectrum, they present opportunities to help the department alleviate some of its wireless communications problems.The Texas National Guard, for example, recently deployed a WiMax system from Nortel Government that operates at 5.8 GHz to support disaster response operations. Personnel from the Naval Postgraduate School used Redline Communications’ WiMax equipment in a Thailand network last year to support tsunami relief operations.Although commercial uses should not jeopardize national security spectrum requirements, the world faces a spectrum crunch, and DOD and the United States need to develop creative ways to use a finite resource, said Richard Russell, associate director of the White House Office of Science and Technology Policy. Spectrum has become an economic engine that powers many American high-tech companies, he added.Kneuer said DOD could find relief for its WiMax radar interference problems by applying the fix developed at the 2003 Word Radio Conference to ensure Wi-Fi devices operating at 5.8 GHz do not interfere with radars by using a process called Dynamic Frequency Selection to avoid channels used by radars. The next conference, sponsored by the International Telecommunications Union, will be held in Geneva next year.