SAS - Why does the SAS allow interference between GAA users?

[James_S]

Happy Friday! Sometimes, CBRS operators ask why it is that the SAS allows CBSDs from different operators to request GAA grants that interfere with each other.

Under PART 96, Spectrum Access Systems (SASs) are obligated to guarantee interference protection to Incumbents and PAL licensees. However, PART 96 does not provide SASs any jurisdiction in arbitrating General Authorized Access (GAA) spectrum among contending operators. In other words, under PART 96, SASs cannot reject GAA grants or channels when requested from users, as long as the incumbent or PAL is protected.

PART 96 encourages operators to coordinate GAA spectrum to minimize interference. Google has been leading the effort in developing a Collaborative GAA Coexistence framework for the industry in the OnGo Alliance. The Collaborative GAA Coexistence Framework requires that all operators opt-in to the coordination process, and that the SAS (or multiple SASs) involved facilitate the coordination process in terms of defining a coordination area and eventually reaching an agreement on the GAA Frequency plan.

It should be noted that this process requires all parties within the coordination area to opt-in to the framework; otherwise, the process does not work. If everyone opts into the process of coordination and agrees on a GAA frequency plan within a coordination area, only then does it provide SAS a mandate to execute or carry out the GAA frequency plan.

Google SAS has been providing support for coordination of GAA channels where possible among operators by providing channel recommendation and guidance. With the approval of operators, Google SAS also facilitates communication between operators so that operators can coordinate their GAA channels. However, these efforts only work if all the operators or users operate within the recommended channel or any agreed upon coordination. An industry-wide Collaborative Coexistence Framework, as being developed in the OnGo Alliance, is required to streamline and guarantee wider adoption of this process.