| Popis: |
The diversification of multimedia service makes the manifest increasing of bandwidth requirement in the future communication service. For efficiently using the bandwidth resource, the cell size of the cell structure based mobile communication system is reduced. Reducing the cell size to promote the utilization of resources, however, increases the handoff frequency in the meantime. During the handoff process, if the bandwidth utilization of the target cell is high, connection break off is unavoidable. To reduce the occurrence of break off, reserving bandwidth for mobile terminal (MT) before handoff is feasible. In this paper, we try to use the grey theory to predict the trajectory of MT, so as to judge the target cell of the MT. Meanwhile, by using the information such as the distance between MT and base station (BS), the velocity of the MT, the required bandwidths of the MT and the available bandwidth of the target cell, we construct a fuzzy system to determine the necessity of handoff and the amount of reserved bandwidth. |
