Guaranteed time slot performance and synchronous data acquisition with sensor nodes in IEEE 802.15.4 Standard

In some of the sensor network applications, low latency and reserved bandwidth to a particular device may have a significant importance. Guaranteed Time Slot (GTS) mechanism defined in IEEE 802.15.4 Standard provides solutions for such necessities. In this study, performance of GTS is measured on 13192 Evolution Kit modules from Freescale Semiconductor. This performance is compared with the theoretical throughput and maximum goodput values. Besides the performance measurements, synchronous data acquisition with two sensor nodes has been successfully realized. Synchronization of sensor nodes or chronologically sorting the events happened in a WSN are important phenomenon that need to be considered carefully for direction of arrival, array signal processing or surveillance applications. In order to synchronize the nodes beacon notification indication primitive defined in the 802.15.4 standard is used in the developed applications. Thus, each reception of beacon from the coordinator of the WSN resynchronizes the nodes.