Kamarudin Saadan

Enhanced TCPW's fast retransmission and fast recovery mechanism over high bit errors networks

In this paper we introduced two enhancement modifications to the well-known TCP Westwood fast retransmission and fast recovery mechanisms. Firstly, a new modification is introduced to fasten the fast retransmission procedure by preventing the TCP sender side from waiting the third duplicate ACKs to retransmit lost packets. Secondly, further modification is presented to achieve better recovery for the congestion window size in the fast recovery phase based on last round trip time and bandwidth estimation. The two modifications are implemented and evaluated using ns-3 simulator. We compared the throughput and congestion window size of the new proposed modifications to TCPW and NewReno. As a result, the proposed algorithm has shown significant improvement over the two implementations.

Cell drop threshold architecture for multi-class shared buffer with finite memory size

Shared buffer is commonly used to utilize the buffer in the switch. In order to minimize the cell lost of high class traffic in multi-class switch, the threshold is set to drop the low class cells in the shared buffer. This will give more space to accommodate the high class traffic cells. In this paper, we analyse the performance of shared buffer with different threshold settings. The multi-class shared buffer architecture is developed for 16×16 ports switch, which is targeted for Xilinx FPGA implementation. The performance of the multi-class shared buffer switch is analysed in term of the achievable throughput as well as the drop probability. Based on the simulation with different threshold settings, it is observed that the optimum selection of cell drop threshold depends on the size of the shared buffer that triggers the RAM threshold.

Wireless landmines tracking system based on GPS and GPRS

One of the most challenges facing the developing countries and standing in the way of their growth are remnants of war and landmines. These countries have inherited this legacy during the World War I and II which represents a major threat to lives. Furthermore, it hinders reconstruction and development efforts. The aim of this research is to find a low cost alternative for protecting and warning people about landmines risk during practicing their daily lives. In this context, this paper presented the design and development of a Wireless Landmines Tracking System (WLTS) using smart phone. The Android software development kit (SDK) has been used to develop this system. This system is really very helpful for the users who live near mine affected areas to track their children and themselves through mobile phones from landmines risk.

Implementation of multi-class shared buffer with finite memory size

High packet network have become an essential in modern multimedia communication. Shared buffer is commonly used to utilize the buffer in the switch. In this paper, we analyse the performance of shared buffer with different memory sizes. The architecture of the multi-class shared buffer is developed for 16×16 ports switch that is targeted in Xilinx FPGA. The performance of the multi-class shared buffer switch is analysed in term of throughput and mean delay. Based on the simulation with different memory sizes, it is observed that the optimum selection of memory size under uniform traffic depends on the maximum traffic load of the switch.