| Abstract: | A mathematical model of channel assignment with prioritized handoff procedures is given according to the physical handoff process in GSM networks with some reasonable simplifications and assumptions, and a numerical calculation is applied to the model. A simulation model is established to verify the results of the mathematical model. The results show that the overall loss probability is increased with the number of channel reservation increasing, although the probability of forced termination can be reduced. Therefore, three queuing schemes are proposed: (1) queuing for handoff calls without channel reservation, and the queuing rule is "First come, first served"; (2) queuing for handoff calls without channel reservation, and the queuing rule is "First come to the threshold, first served"; (3) queuing for new calls with one channel reserved for handoff calls. Simulations are also made for the three queuing schemes, the results indicate that the third one is the best, and it is also easy to realize. The optimal queuing length and the maximum waiting time are suggested for the third scheme. |
