Performance improvement of ad hoc networks using directional antennas

We investigate preventive link maintenance scheme to on-demand routing algorithms. The scheme of creating directional link is proposed to extend the life of link that is about to break. We see the performance improvement at network layer by using the proposed scheme. We do a comparative performance study between omni directional and directional antennas for DSR (On-demand routing protocol) using simulation with OPNET. By using directional antennas, substantial gain is achieved in terms of end-to-end delay, aggregate throughput, average data packets dropped, packet delivery ratio, and routing overhead. The proposed scheme is general and can be used with any other on-demand routing algorithms

An enhanced approach for augmentation of synchronized bandwidth request in WiMAX

This paper carried out a study on the bandwidth request for real-time polling services. In our study, we discovered that although the base station granted the subscriber station to send the bandwidth request, the subscriber station may not be able to allocate the bandwidth request. It is due to processing delay and multicast polling in the subscriber station, which results the bandwidth request being padded unintentionally. The loss of bandwidth requests will cause the degradation of the real-time polling service performance. Therefore, we propose a scheme to overcome this problem. The results of the experiment show that the proposed scheme improves the performance of real-time polling services