Providing a good Quality of Service (QoS) for all users is a big challenge in Cellular Networks, as soon as the number of users increases the demand on Internet service increases too especially with using the current technology of today. While on move a user needs Internet connectivity with good Quality of Service and minimum call dropping probability. Cellular IP presents a good solution mobility as it supports highly mobile users, users' needs are becoming larger and more multifarious (files downloading, video streaming, sending an e-mail….) there for the need for efficient way to improve QoS is necessity. Bandwidth is the most important factor in Cellular IP Networks, for improving QoS in Cellular IP Networks a model for bandwidth management is presented in this paper, the model presented here is based on borrowing bandwidth reserved to non-real-time users using Particle Swarm Optimization (PSO) the proposed model preserves a low bandwidth threshold for the ongoing non-real-time calls. This threshold is the security limit that keeps non-real-time calls from being dropped. This research models handoff process and proposes a technique that gives the lowest percentage of dropped and blocked hand offs. Simulation results show the efficacy of the proposed model.