Enhancement Of Medium Access Control Protocol With Various Services Utilizing Capture Effect

In recent years there has been considerable interest in the development of standards for Wireless Local Area Networks (WLANs). In particular, IEEE 802.11 standard has now been extended to several variants of WLAN standards. For this reason, much of the research work for the enhancement of MAC protocol for WLAN is generally is based on the behaviour of the IEEE 802.11 standard. Hence, this thesis focuses on the enhancement of MAC protocols, particularly the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol for variants of WLAN standard. In this thesis, the protocols have been analysed in terms of throughput and transmission delay by using an improved analytical approach simulated in Matlab. The saturation throughput analysis of CSMA/CA is controlled by using slotted analytical model combined with capture effect probability model. The performances of MAC protocols with propagation loss and shadowing scenarios are analysed. The proposed modification significantly reduced the probability of collision and provide better performance. The capture effect 10dB and retransmission 5 times has been achieved for the overall performance of the protocol, which shows almost 0.69% improvement at the average transmission delay and 0.80% at the throughput. The maximum throughput of MAC protocols is dependent on the normalized propagation delay. In other word, smaller normalized propagation delay gives better performance of throughput. Moreover, shorter distance has higher throughput and lower transmission delay for both path loss and shadowing scenarios when compared to the longer distance. Furthermore, the performance of average transmission delay for MAC protocols with capture effect is better than the MAC protocols without capture effect. These results can be used as a useful guide to scientist and engineers before the communication network is deployed to transfer data to the gateway or control centre

A review on various types of Software Defined Radios (SDRs) in radio communication

Software Defined Radio (SDR) promises to deliver a cost effective and flexible solution by implementing a wide variety of wireless protocols in software. The SDR became more popular in recent years because of its abilities to realize many applications without a lot of efforts in the integration of different component. This software based radio device allows engineers to add more features to the communication system and implement any number of different signal processing elements or protocols without changing the original system hardware and its architecture. It provides a customizable and portable communications platform for many applications, including the prototyping and realization of wireless protocols and their performances. It is also able to interface with a separate hardware module to communicate over a real channel. In this article we described and compared the various SDRs that currently has been using by the researchers to study the performance of wireless protocol. Among the SDRs that we focused in this article are USRP, SORA, Air blue, SODA, and WARP