Throughput and Range Performance Investigation for IEEE 802.11a, 802.11n and 802.11ac Technologies in an On-Campus Heterogeneous Network Environment

This paper presents an analysis and measurement results for an experimental study on throughput, range and efficiency performance of IEEE 802.11a, 802.11n and 802.11ac standards in an indoor environment on a typical University Campus. The investigation considers a number of key system features including PHY layers mainly, Multiple Input Multiple Output (MIMO), Multi-User Multiple Input Multiple Output (MU-MIMO), Channel Bonding and Short-Guard Interval (SGI) in the heterogeneous wireless network. The experiment is carried out for the IEEE 802.11ac standard along with the legacy protocols 802.11a/n in a heterogeneous environment which is typically deployed on Campus. The results compare the maximum throughput of IEEE 802.11 standard amendments, in terms of theoretical and experimental throughput over TCP and UDP protocols for different set of parameters and features to check their efficiency and range. To achieve this desired goal, different tests are proposed. The result of these tests will help to determine the capability of each protocol and their efficiency in a practical heterogeneous on-campus environment

Cross-layer design and optimization of medium access control protocols for wlans

This thesis provides a contribution to the field of Medium Access Control (MAC) layer protocol design for wireless networks by proposing and evaluating mechanisms that enhance different aspects of the network performance. These enhancements are achieved through the exchange of information between different layers of the traditional protocol stack, a concept known as Cross-Layer (CL) design. The main thesis contributions are divided into two parts. The first part of the thesis introduces a novel MAC layer protocol named Distributed Queuing Collision Avoidance (DQCA). DQCA behaves as a reservation scheme that ensures collision-free data transmissions at the majority of the time and switches automatically to an Aloha-like random access mechanism when the traffic load is low. DQCA can be enriched by more advanced scheduling algorithms based on a CL dialogue between the MAC and other protocol layers, to provide higher throughput and Quality of Service (QoS) guarantees. The second part of the thesis explores a different challenge in MAC layer design, related to the ability of multiple antenna systems to offer point-to-multipoint communications. Some modifications to the recently approved IEEE 802.11n standard are proposed in order to handle simultaneous multiuser downlink transmissions. A number of multiuser MAC schemes that handle channel access and scheduling issues and provide mechanisms for feedback acquisition have been presented and evaluated. The obtained performance enhancements have been demonstrated with the help of both theoretical analysis and simulation obtained results

Performance Enhancement in SU and MU MIMO-OFDM Technique for Wireless Communication: A Review

The consistent demand for higher data rates and need to send giant volumes of data while not compromising the quality of communication has led the development of a new generations of wireless systems. But range and data rate limitations are there in wireless devices. In an attempt to beat these limitations, Multi Input Multi Output (MIMO) systems will be used which also increase diversity and improve the bit error rate (BER) performance of wireless systems. They additionally increase the channel capacity, increase the transmitted data rate through spatial multiplexing, and/or reduce interference from other users. MIMO systems therefore create a promising communication system because of their high transmission rates without additional bandwidth or transmit power and robustness against multipath fading. This paper provides the overview of Multiuser MIMO system. A detailed review on how to increase performance of system and reduce the bit error rate (BER) in different fading environment e.g. Rayleigh fading, Rician fading, Nakagami fading, composite fading