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Table 2 Notations and definitions used for WF-MAC

From: Quality-of-service-aware weighted-fair medium access control protocol for coexisting cognitive radio networks

Notation Description
\(\mathcal {M}\) Set of Licensed channels; { 1,2,3,…,m}
\(\mathcal {N}_{r}\) Set of SUs of CRN r; { 1,2,3,…,n}
Ω Set of traffic types
ρ Priority value assigned to a specific traffic
H i Status of channel i; { 0,1,2}
t Time needed to sense a channel
σ s Number of retransmissions for collision with SU
σ p Number of retransmissions for PU appearance
\({\lambda ^{s}_{i}}\) SU arrival rate over channel i
\({\lambda ^{p}_{i}}\) PU arrival rate over channel i
\(\mathcal {E}\) Channel availability vector
\(\mathcal {U}\) Channel utility perception vector
\(\mathcal {O}\) Channel usage outcome { o 1,o 2,o 3,o 4}
C W ρ Contention window for packet priority type ρ