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Table 1 Notations used in the paper

From: Multichannel MAC protocol with dynamic backoff contention for distributed cognitive radio networks

Symbol

Explanations

N

Number of SUs in the DCRN

N st

Number of successful transmission pairs in a MAC cycle

M

Total number of licensed data channels

M ic

Number of idle licensed channels

M sic

Number of remaining sensed idle licensed channels

K

Largest number of slots for the contention phase

w i

Average number of winning slots (successful SUs) in the ith backoff

 

contention window

W

Number of slots won in the whole contention phase

Q

Parameter which is broadcasted on the update slot to indicate the

 

number of contention slots of the next backoff window

Q 1

Number of contention slots in the first backoff window

Q i

Number of contention slots in the ith (i>1) backoff window

Q c

Number of contention slots in the whole contention phase

P d

Each SU’s local detection probability

P f

Each SU’s local false alarm probability

P s

Probability of a successful RTS contention in the initial backoff window

P T

Probability of a successful data transmission in a MAC cycle

P NT

Probability of fail to transmit data in a MAC cycle

D

Average channel access delay in terms of MAC cycles

T cycle

Time duration of a MAC frame cycle

T c

Time duration of contention phase

T ct

Time duration of contention phase and transmission phase

T tr

Time duration of data transmission phase

α

Average utilization probability for all the licensed channels

σ

Duration of a contention slot in contention phase

R

Fixed rate for each data channel

n 1

Number of remaining SUs (which still need contention) in Algorithm 1

n 2

Number of remaining contention slots in Algorithm 1