GALS with CDMA based access scheduling for Wireless Internet of Things

Channel allocation and Channel access are considered to be the most important issues in Wireless Communication System. MAC protocols for wireless sensor networks based on CSMA/CA induce high overhead due to RTS/CTS packets and does not completely eliminate hidden terminal problems. A new technique, called Grid based Channel allocation and Access scheduling using Latin Squares (GAALS) can be effectively used for Channel allocation and Channel access. GAALS effectively increases the throughput and reduces end to end delay as well as jitter. Time division Multiple Access (TDMA) is used for both Channel allocation and Channel access in GAALS. In this paper, GAALS is modified to GALS, where grid based channel allocation using Latin Squares is done; but alternate techniques like Frequency Division Multiple Access (FDMA) and Code Division Multiple Access (CDMA) are considered for channel access and they are compared. Performance metrics which are used for comparison include throughput and delay. Simulation result shows that CDMA is a better channel access technique as compared to all the other techniques for channel access.