QoS Strategies for Wireless Multimedia Sensor Networks in the Context of IoT at the MAC Layer, Application Layer, and Cross-Layer Algorithms

Table 2

Comparison of MAC layer protocols used in QoS provisioning.

Protocol	Features	QoS parameter	Comments	Access	Priority assignment	Energy eff.	Designed for
S-MAC [22]	Collision avoidance	Energy, latency	Requires periodic synchronization	CSMA	Hybrid	Medium	WSNs
B-MAC [23]	Collision avoidance	Energy, delay, throughput	Flexible interface	CSMA	Dynamic	High	WSNs
T-MAC [25]	Collision avoidance	Energy	Complex, nonscalable	CSMA	Dynamic	High	WSNs
C-MAC [13]	Dynamic channel allocation	Energy	Multichannel MAC	CSMA	Dynamic	Medium	WSNs
CU-MAC [24]	Multichannel mechanism	Throughput, latency	High packet delivery ratio	TDMA	Dynamic	—	WSNs
A-MAC [39]	Per flow service guarantees	Delay	m-ary tree model, dynamic priorities	TDMA/CSMA	Dynamic	Medium	WSNs
ER-MAC [30]	Emergency response	Energy, delay, delivery ratio	Adapts to traffic and topology changes	TDMA/CSMA	Hybrid	Higher than Z-MAC	WSNs
RI-MAC [31]	Collision detection	Delay, packet delivery ratio	High packet delivery ratio and throughput	CSMA	Dynamic	Medium	WSNs
SRI-MAC [33]	Collision avoidance	Energy, delay	Good data transfer and energy consumption	TDMA	Dynamic	High	WSNs
H-MAC [34]	Slotted sleep time	Throughput, latency	Data transmission only in sleep time	CSMA/Aloha	Dynamic	Medium	WSNs
Z-MAC [36]	Collision avoidance	Energy, delay, throughput	Very good channel usage and error sync	CSMA/TDMA	Dynamic	Medium	WSNs
Q-MAC [37]	Intra/internode scheduling	Energy	High QoS, improved energy efficiency	CSMA	Hybrid	High	WSNs
X-MAC [32]	Overhearing avoidance	Energy, delay, throughput	Reduces excessive preamble by strobing	CSMA	Adaptive/static	Medium	WSNs
L-MAC [40]	Collision avoidance	Network lifetime, energy	Reduces the number of transceiver switches	TDMA	Static	Medium	WSNs
WiseMAC [38]	No downlink channel collision	Power, delay	Significantly low-power consumption	Aloha/CSMA	Static	Higher than Zigbee	Infrastructure WSNs
AR-MAC [27]	Collision avoidance	Energy, delay	Uses data packets and control packets	TDMA	Static	Higher than IEEE 802.15.4	WBANs
BB-MAC [42]	Real-time traffic prioritization	Delay	Employs round robin in real-time nodes	CSMA/TDMA	Dynamic	High	WMSNs
COM-MAC [41]	Collision avoidance	Packet delay, throughput	Balances reliability and retransmission	TDMA/FDMA	Dynamic	High	WMSNs
EQoSA [14]	Busty traffic load accommodation	Energy	Provides QoS support for video and images	TDMA/CDMA	—	High	WMSNs
QE-MAC [42]	Collision avoidance	Energy, jitter, latency	Runs central polling-like channel access	CSMA	Dynamic	High	WMSNs
R-MAC [26]	Collision avoidance	Energy, delay	Reservation based	—	Static	High	Underwater SNs