A Study of Timing Constraints and SAS Overload of SAS-CBSD Protocol in the CBRS Band

This research work studied the effect of timing constraint and overloading of Spectrum Access System (SAS) on the SAS-CBSD protocol. Specifically, it studies how Heartbeat and Grant Request fail as number of CBSDs served by a SAS becomes large for a given service rate. It also looks at the time taken by CBSDs to vacate a channel (on which an incumbent has appeared) at different Heartbeat Interval. These study results are captured in the following files.(1) Number of CBSD vs number of Heartbeat timeout when SAS service rate is 40 requests/sec(2) Number of CBSD vs number of Heartbeat timeout when SAS service rate is 60 requests/sec(3) Number of CBSD vs number of failed grants when SAS service rate is 40 requests/sec(4) Number of CBSD vs number of failed grants when SAS service rate is 60 requests/sec(5) CDF of duration of CBSDs vacating a channel when number of CBSD=700, mean heartbeat interval = 90 s(6) CDF of duration of CBSDs vacating a channel when number of CBSD=1200, mean heartbeat interval = 150 s(7) CDF of duration of CBSDs vacating a channel when number of CBSD=1500, mean heartbeat interval = 220 s