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

Table 9

Proposed protocols/algorithms for mitigating unnecessary idle listening in SMAC protocol.

Reference	Problem	Proposed solution/Purpose	Description	Limitations
[193]	Unnecessary idle listening	CL-MAC protocol	The protocol utilizes routing layer information to determine nodes that need to be awake to communicate. Hence, nodes in sleep modes are excluded from the routing paths for data transmission.	# It does not ensure fairness in terms of the traffic loads
				# Simulation tool not stated.
[65]	# Unnecessary idle listening	# A mechanism known as announce to send (ATS) is proposed	ATS solves unnecessary idle listening in SMAC by proactively informing its neighbour nodes of their transmission plan.	# Overhearing and packet collisions
	# Fatal bugs in the original implementation of SMAC in NS-2	# The original implementation of SMAC was modified to fix fatal bugs