The wireless cellular network (WCN) provides services to many users with limited radio resources. In WCN, resource allocation is important to provide the desired quality of service (QoS). Among the two possible types of calls in WCN, hand‐off calls (HCs) have higher priority than new calls (NCs). In this paper, we developed a mathematical model to estimate call blocking using an optimal number of guard channel (GC) for HCs by considering target hand‐off call dropping probability (HCDP). We named this model the optimal guard channel reservation (OCR) policy. This analytical model assumes the long‐term average of the traffic parameters and so is far from making any correlation with the operation of the existing system. In real, the traffic parameters are dynamic. Further, we proposed an optimal adaptive guard channel reservation (OACR) policy to obtain optimal performance. It adjusts the GCs dynamically w.r.t the traffic conditions to keep HCDP below the target. We have implemented the OACR scheme by using a test bed. Finally, we have applied both mathematical model (i.e., OCR policy) and OACR policy to a wireless cellular network, that is, Global System for Mobile Communication (GSM) 900 system.