PERFORMANCE IMPROVEMENT OF WI-FI CONNECTIVITY USING SMART ANTENNA

 2.7      Transmission part of smart antenna at BS for downlink (International Engineering Consortium, 2010).              18

BSS                 Basis Service Set

CAC               Channel Access Control

CRRS             Chip Rate Reference System

DTBS             Distributed Time Bound Services

DCF               Distributed Coordination Function

DSSS              Direct Sequence Spread Spectrum

DSP                Digital Signal Processing

DPDCH          Dedicated Physical Data Channel

Wireless-Fidelity (Wi-Fi) is widely implemented in campus. Wireless communications are associated with interconnecting devices which includes cellular networks, infrared, bluetooth and Wi-Fi enabled devices. It involves mobility and freedom of assessing information anytime and anywhere. A study on Wi-Fi networks in a campus environment is presented in this project. The aim of the research was to investigate the connectivity problems to Wi-Fi networks. The study includes Wi-Fi performance analysis as well as network auditing.

The internet traffic requirement has grown remarkably in the last couple of decades, and it is predicted to scale even further in the upcoming years. On the other hand, internet users are increasingly relying on Wi-Fi for the last mile connectivity. Wi-Fi has been used in a broad range of applications not only in enterprises but also in the daily activities. Thus, technologies that can fundamentally enhance Wi-Fi connectivity are desirable. Research on next generation Wi-Fi networks is focusing on a variety of goals including performance (i.e., system throughput and channel efficiency), controllability, security, power consumption, adaptability, etc. The goals of this research are improving performance to support the level of connectivity, and promoting controllability to support service differentiation and even performance prediction. Performance goals pertain to achieving better throughput and channel efficiency for a wide range of network conditions with the highest degree of adaptability.

Controllability goals are akin to the goals of software-defined networks and focus on future proofing systems, manageability, and service differentiation capabilities.

First algorithms that improve the performance in the physical layer with only changes in Access Points (APs) were proposed. Smart antenna technology plays an important role for performance enhancement in the physical layer of Wi-Fi. While most smart antenna techniques require changes in both APs and stations, beamforming is a mechanism that can be applied with only changes in APs. A set of algorithms that can provide benefits of beamforming to legacy nodes by only adopting new APs was also proposed. It focused on heavy multipath fading indoor environment (such as enterprise offices or school classrooms), which is a typical environment for legacy Wi-Fi infrastructure.

Secondly, future-proofing networks with a central controller and enable micro-level controllability to support service differentiation and performance prediction were considered. The study focused on how to enable the controllability of Wi-Fi networks without compromising their scalability when a central controller is available. A media access control (MAC) protocol called Rhythm, which transfers the control of Wi-Fi networks into centralized scheduling, with the properties of (i) low protocol overhead, (ii) work conservation in the presence of non-backlogged nodes, (iii) robustness to partial connectivity scenarios was introduced.

Wireless network coverage is one of the fundamental problems in wireless network. Wireless Access Points (AP) are nowadays deployed widely in the campus area and poor connectivity to Wi-Fi network at certain areas is one of the major problems. Users have either a Personal Computer or Laptop, and fast connection to the campus real time system as well as to the Internet are their expectations. In relations to the Wi-Fi coverage, sometimes users are not able to detect a WiFi node. Although some of the users were able to detect the node, the signal strength was very low. At the same time some users managed to detect very good signal but they can neither access the Internet nor the local server. The slow Internet Access could be due to users playing online games within the wireless network thereby slowing the network performance. Another cause for slowdowns is lack of bandwidth. If everyone is using their computers and phones for data-hungry applications, the typically speedy Internet is being spread thin and shared across multiple devices. Therefore, this research work addresses the problem of non-availability of signal by integrating smart antenna in improving Wi-Fi connectivity.

The aim of the research work is to improve Wi-Fi connectivity using smart antenna. The specific objectives include:

2.    To characterize the Wi-Fi Network under study

The problem of channel impairment using smart antenna can be solved by improving channel capacity of the mobile system and also, achieve higher data rate and range extension which can help in increasing the economy of the world by making business transaction easy.

Smart antenna environment is very wide and cannot be consummated in this study.  Therefore, the research work has been limited to smart antenna in relation to propagation impairment detection that limits the performance and capacity of wireless system and demonstrating the effect of smart antenna in information transmission process in mobile communication systems.

This project is divided into five chapters. Chapter 1 contains the background of the study, problems and objectives of the research with the significance. Chapter 2 reviewed existing literature on wireless network connectivity. Chapter 3 presents the methodology and design of project in which smart antenna technique was used. Chapter 4 presents the system parameters with simulation results and discussions. Chapter 5 presents the summary of the project, conclusions, recommendations and research contributions to knowledge.