A MAC Protocol of Concurrent Scheduling Based on Spatial-Temporal Uncertainty for Underwater Sensor Networks

Table 1

Symbols.

Terms	Explanation
SID	The ID of sending node
	The ID of child node
	The number of all child nodes of node with layer “”
	The speed of sound in water
	The transmission rate of channel
	Size of a packet
	Maximum packet length in the network
	Time the sender starts to send packets
	Time the receiver to finish receiving packets
	Layer of node
	Neighbor table of the node
	Duration of one listen/sleep cycle
	Duration of node waking (including idle listening and working times)
	Duration of node working (including sending or receiving times)
	Duration of node idle listening
	Duration of node sleeping
	Duration of a ACK frame
Pos	Location of the node
	Distance between the sender and receiving nodes
	Maximum transmission distance in network
	Maximum distance offset for node movement