CMD: A Multichannel Coordination Scheme for Emergency Message Dissemination in IEEE 1609.4

Table 4

Notations.

Acronym	Description
	The packet arrival rate
	Average service rate of the queue in packets per second
	The probability that at least one packet is in the queue =
	Is the back-off blocking probability
	The packet arrival probability =
	Contention window size for back-off
	Current window size state as an effect of exponential back-off
	Idle state
	Traffic density
	The reference distance used in calculating the received signal strength at a particular distance
	The received signal strength at specified distance
	The critical distance that refers to the distance where the first Fresnel zone touches the ground and is also referred to as the Fresnel distance
	Path loss exponent
	Path loss exponent
	Transmitter height
	Receiver height
	Electromagnetic wavelength fixed at 5.9 GHz
	The number of vehicles in carrier sensing range
	The zero mean, normally distributed random variables with standard deviation
	The zero mean, normally distributed random variables with standard deviation
	The carrier sensing range defined as the average distance for a node to detect the other nodes transmissions
	The carrier sensing threshold which indicates the receive sensitivity of the radio and is a constant and radio dependent