The development of enhancing mechanisms for improving the performance of IEEE 802.15.4

摘要

There has been increasing interest in wireless network system in recent years, yet there are many issues to be resolved, mainly on topics related to its application design, such as the field of robot, artificial intelligence, and healthcare system etc. IEEE 802.15.4 is a standard protocol needed to achieve the low cost, low power consumption and low data rate Low-Rate Wireless Personal Area Network (LR-WPAN) widely used in remote metering, building automation, toys, smart tags, industry control, etc. The IEEE 802.15.4 protocol specifies the inclusion of a physical layer (PHY) and Medium Access Control (MAC) sub-layer for LR-WPAN. The PHY contains three different frequency bands comprised of 27 radio frequency channels. The MAC sub-layer handles all access to the physical radio channel. The MAC protocol controls potential contention and collisions but the slotted CSMA/CA algorithm cannot effectively avoid collisions in IEEE 802.15.4. Therefore, the transmission performance is affected. Most current research is focused on reducing power consumption, the development of enhanced routing approaches and the like. Studies focused on reducing collision problems are rare. In this study, two novel hash channel selection mechanisms for improving performance of IEEE 802.15.4 are proposed. Meanwhile, a star topology is constructed for simultaneous simulation and evaluation of the hash mechanism using NS-2 simulations. The results of the simulation reveal that the proposed hash mechanisms offers improved throughput, utilization, average delay and drop-off performance in all respects for IEEE 802.15.4 by about 100%.   Keywords: IEEE 802.15.4, MAC, Hash channel selection, Transmission performance