This paper presents the modeling and performance analysis in the integrated ad hoc and cellular network systems. In the modeling of the other integrated systems [7, 10, 12, 14, 17], the handoff area was not considered. However, for mobile communications, handoff area is important, complicated and unstable area that is the boundary of cells. In our system, handoff area and queue are taken into consideration, and new and handoff calls are given priority, respectively. We derive and evaluate some characteristic values such as the mean waiting time. In numerical results, the analytical results in our system are compared with those in the other integrated system, and with the simulation results for the validation.