Simplicity is key to successful spectrum sharing, Rysavy says

A plan consisting of many small, simple steps will be the best approach to developing a successful system for spectrum sharing with government entities, such as the U.S. Department of Defense (DoD), according technology consultant Peter Rysavy.

Determining how best to share first the AWS-3 band and later the 3.5 GHz band has generated numerous concerns, but that each identified challenge is solvable through investigation and development, Rysavy said during a recent Mobile Future webinar. The key is to simplify spectrum sharing as much as possible in the process, he said.

“I think the best way forward is to always take the smallest step possible and to not overreach and create a scenario where the issues are so complex that people just walk away from them,” Rysavy said.

“If it’s onerous for either side–either the incumbent or the secondary users–sharing will not be successful. There are so many ways that sharing can be thwarted that, unless we keep it straightforward, unless we minimize the number of systems we have to share with and unless we really define the appropriate, clear, easy-to-understand use cases, then we will just be undermining our efforts.” 

One concern is that government will rely on overly conservative assumptions to protect its systems, leaving little useful spectrum for industry, and that government will use “inappropriate or overly simplistic modeling” to stake out exclusion and protection zones, Rysavy said.

Other concerns revolve around the immaturity of the system, the disparity and multiplicity of government systems, restricted DoD information leading to limited industry analysis and many other issues.

“These concerns are not just for AWS-3. They’re also for 3.5 GHz,” Rysavy said. “If the assumptions are too conservative, it’s possible that the exclusion zones would be so huge that the remaining spectrum would simply not be that useful to industry.

“My view is that government should vacate as many systems as possible to simplify how sharing (for AWS-3) is going to occur.”

Part of that strategy would include the adoption of simple sharing and coordination approaches, Rysavy said.

“My thinking on this is wireless is hard to begin with,” he said. “Making it any harder than necessary will have adverse consequences, and it will result in inefficient spectrum use, which really defeats the whole purpose of all this work.”