In cellular networks, wireless channels are a scarce resource and therefore must be used efficiently. Allocation of channels to individual cells can be done either by a centralized method or a distributed method. Under both approaches, available channels can be either pre-allocated to cells initially or can be allocated to them whenever the need for additional channels arises. We observe that if channels are not pre-allocated to cells, the channel reuse pattern may not be compact, and therefore may result in inefficient use of the available channels. However, the effect of channel pre-allocation on the performance of channel allocation protocol has not been studied in depth. In this paper, we study this effect quantitatively. In order to do this, we propose an adaptive channel allocation protocol, which allows a subset of available channels to be pre-allocated to cells, while the rest are being kept in the open pool. Results from our performance evaluation indicate that a channel allocation protocol that pre-allocates all channels to cells achieves a low call failure rate, a low call blocking rate, and a low handoff drop rate.