We present the modeling and evaluation in the integrated cellular
and ad hoc network system. The system is modeled using queueing theory and we derive some characteristic values. As regards a system model of two cells, <i>M</i> channels are assigned to each cell and a relay station is set in the overlapped area of two cells. New calls in cell<i>A</i> can be relayed to cell<i>B</i> if the channels in cell<i>A</i> are all busy and the mobile stations are in the covered area by a relay station. Handoff calls select the channels of the cell that the number of empty channels are more in the two cells.
If the channels of the both cells are all busy, handoff calls can wait in a queue with the capacity <i>Q</i> while mobile stations are in the handoff area. However, so as not to make handoff calls possess channels prior to new calls, we manage it with the method being different from the other researches. This system is more flexible than cellular networks, the bias of traffic gets smaller and it leads to an efficient channel using. We model and evaluate our system
by assuming that the dwelling time is distributed with non-exponential distribution as well as exponential one. In numerical results, we compare the characteristic values in our system with those in non-relaying system, see how the characteristic values are affected when the covered area by a relay station changes, and verify the effectiveness of our system.