Symbol | Meaning |
---|---|
t sp1 | the most recent time when the channel switches from ON state to OFF state |
t i | the time of the i th data transmission of SU in Stage I |
| the i th data transmission time period in Stage I |
t sp2 | the most recent time when the channel switches from OFF state to ON state |
| the time of the j th data transmission in Stage II |
| the j th data transmission time period of Stage II |
P s | the transmission power of SU in Stage II |
Q th | the threshold to the queue length of SU transmitter in Stage II |