A Survey of Adaptive and Real-Time Protocols Based on IEEE 802.15.4
The IEEE 802.15.4 standard is a protocol that has been widely used in many applications exploiting Wireless Sensor Networks (WSNs). In this paper, the authors first discuss the negative aspects of IEEE 802.15.4MAC in contention access period, contention-free period, and the overall cross-period, respectively, in terms of adaptive and real-time guarantees. They then give an overview on some interesting mechanisms used in existing adaptive and real-time protocols in compliance with IEEE 802.15.4. Careful examination of such research works reveals that by optimizing the original specifications and dynamically adjusting the protocol parameters, the total network efficiency can be significantly improved. Nevertheless, there are still certain challenges to overcome in pursuing the most appropriate protocol without introducing any unacceptable side effects.