Enhancements of IEEE802.15.4e DSME Model of Wireless Sensor Networks

摘要

Internet embedded sensor nodes have attracted the attention of researchers and industry due to their wide application. The main standard, IEEE802.15.4e 2012, introduces a deterministic and synchronous multi-channel extension (DSME) model. Three main issues should be tackled and improved with this model; a high energy consumption of end nodes during the contention access period (CAP), a long association and guaranteed time slot (GTS) earning times during a network initialization phase and a long network discovery time. These issues have been analysed and improved in a star topology wireless sensor network (WSN). Four scenarios with different numbers of nodes are investigated. Nodes numbers are set according to network saturation ratios (25%, 50%, 75%, and 100%). This paper proposes three enhancements for the performance of this model. Two new approaches are proposed to reduce the energy consumption of end nodes during the CAP period, a new association scheme during network initialization phase using a tight TDMA algorithm to minimize the time required for association and getting a GTS slot and reduce power consumption due to collisions, and a new technique to reduce network discovery time. Simulation results show significant improvements in reducing energy consumption and radio duty cycle (RDC) of end nodes by a factor of (71) and (77) respectively. Good improvements are also achieved in reducing association and GTS earning times by a factor of (8) on average. Finally, network discovery time has been reduced for fast association and further energy saving of end nodes.