Channel selection observation period length analysis under different channel service rates

In wireless communication, the sender needs to select an optimal wireless channel from several available ones. However, the instantaneous channel state is time-varying with unknown statistics. Therefore, the channel selection must be based on channel observation. Before the packet arrives, the sender needs to observe the channel state in the observation period. And then the sender transmits packets through the best channel. Observation needs cost time. We investigate the trade-off between the observation period and transmission period. A short observation period usually leads to wrong selection while long observation might waste time. Our simulation results show that there is an optimal length of observation period. The total transmission time experience a sharp decrease before the optimal point. The longer observation does not cause an obvious increase in transmission time. We analyze how the observation time affects the transmission time to explain the simulation results.