Possible Solution To Wireless Interference Made

May 6, 2003 - In a letter to the FCC referencing WT Docket No. 02-55, Motorola has offered a technical solution to eliminate interference caused by commercial wireless vendors. Motorola reported that they have been actively working on potential technical solutions to the problem.

The letter states, "Motorola believes that technical advances in receiver design are commercially viable, will have limited impact on the cost of portable public safety equipment and provide a real opportunity for alleviating interference to public safety."

While Motorola acknowledges that it is still in the testing of this technical solution that it does appear to be "promising" and plans to deploy the receiver technology advancements by the end of 2003. This announcement sent shockwaves through the public safety community.

Motorola's new solution involves the implementation of a switchable attenuator "in a way that reduces interference in areas of sufficient desired signal strength while ensuring that the attenuator does not degrade the reliablility of public safety communications by activating when the desired signal is too low."

Testing has been conducted in both the laboratory and in the field. Motorola further states that increasing signal strength is another essential element to the comprehensive solution to interference.

Motorola also states, "Because a technical solution can be focused on areas where interference occurs or is likely, this approach avoids widespread disruption to public safety operations."

While recognizing the serious need for a solution, Nextel worked with public safety agencies developed a plan known as the "consensus plan", which would reduce interference by rebanding and thereby separating spectrum. Nextel had agreed to pay an estimated $850 million to help cover the public safety costs of the spectrum swap. There were and still are many in the public safety community concerned that the $850 million would not be enough to cover the full extent of spectrum swap.

What does this mean to public safety agencies? It appears that Motorola may have developed a new solution that can resolve the interference issues that have arisen between public safety radio systems and Nextel and other commercial wireless services. The solution as described by Motorola, "can be made directly to the radio receivers at a significantly lower cost than any of the other proposed solutions." This does offer a very attractive and less disruptive solution to many public safety agencies, especially those that are not experiencing interference problems.

In a recent MSN Money Report, dated May 08, 2003 - The report stated, "Motorola's submission yesterday to the FCC of an alternative to Nextel's proposed spectrum swap will likely raise concerns about delays in this action." This raises new questions related to the idea of the spectrum swap proposal. A new discussion will have to take place between the FCC, Nextel and all of the public safety agencies that have been involved in the development of this plan.

For Motorola, this places a great deal of credibility on the line. If the Motorola solution does not prove to be as effective as originally thought, it may delay progress on the spectrum swap plan. Further examination will be required to insure that the technical solution offered by Motorola is viable and to determine if the solution alone will solve the interference problem. On the other hand, if the solution is viable, it will have a dramatic and positive effect on the public safety community. In the interim, there is little doubt that this new and attractive proposal will slow the forward momentum of the spectrum swap plan.

There is caution to putting all of the spectrum "eggs" in one basket. While this technical solution may prove to effectively solve interference issues on the portable receivers, it will not eliminate the problem of spectrum limitations limiting many areas around the country. The dilemma is whether or not to proceed (with or without delay) on a parallel course. One very important aspect of the spectrum swap plan is that it increases spectrum available for public safety to the tune of approximately double the existing spectrum.

This also highlights the importance of the HERO Act and simultaneously freeing up spectrum in the 700 MHz band for public safety which has been reintroduced in Congress.

A comprehensive approach may be the best. First, continue on the path to follow through with the spectrum swap plan. Second, aggressively work toward testing and implementation of Motorola's technical solution. Third, aggressively lobby Congress to pass the HERO Act to dedicate new spectrum to public safety.

Charles Werner is Deputy Fire Chief for the Charlottesville, VA FD. He is chair of the IAFC Technology Advisory Group.