SMAC-Based WSN Protocol-Current State of the Art, Challenges, and Future Directions

Table 4

Comparison of studies on semisynchronous low duty cycle MAC protocols.

Reference	Problem solved	Proposed solution	Limitations
[148]	Static clustering, energy dissipation of fixed positions of cluster heads	Low-energy adaptive clustering hierarchy (LEACH)	Fixed clustering structure, designed for homogeneous sensor network scenarios
[172]	Number of transceiver switches, the fixed sleep interval	Lightweight MAC (L-MAC) protocol	Fixed frame length
[150]	Collision, idle listening, channel utilization	Traffic-adaptive medium access (TRAMA) protocol	Increased idle listening and overhearing
[173]	Idle listening, intracluster and intercluster data collisions	Multihop time reservation using adaptive control for energy efficiency (MH-TRACE)	Not adaptable to topological changes
[174]	Latency, channel utilization	Zebra MAC (Z-MAC) protocol	Adds additional overhead to detect abandoned slots, hidden terminal problem
[175]	Idle listening, data collision, delay	Flow-aware medium access (FLAMA) protocol	Complex and inflexible
[176]	The hidden terminal problem of Z-MAC	An improved Z-MAC protocol introduces tiny RTS/CTS packets to address the hidden terminal problem of Z-MAC and an enhanced DRAND algorithm for neighbour discovery	A tradeoff between overheads and collisions