WLAN Local Area Network Computer Science Essay

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Wireless local area network (WLAN) is a local area network that uses high frequency radio signals to transmit and receive data over distances of several feet. IEEE 802.11 group of standards specify wireless LANs technologies. This utilizes spread-spectrum or OFDM modulation technology based on radio waves which communicate between devices in a limited area. This is also known as the basic service set.

The inter working issues between the 3rd Generation wireless network and wireless local area network with wireless internet and the activation of WLAN services are recently came into spotlight. 3rd Generation wireless network provides the low bandwidth and it is too expensive where as in the case of WLAN, it serves the high bandwidth in small areas and inexpensive. For the purpose of home users the wireless has become popular due to ease of installation and location freedom with the gaining popularity of laptops. Using OPNET simulator a deep analysis has been done with leader.

The most widely used wireless local area network is IEEE 802.11 wireless LAN. The main goal of this WLAN is that joint optimization of the single processing algorithms along with the implementation required for the three components to reduce power, area and latency.


This project would not be possible without my professor and parents. It is my pleasure to thank my professor-------------for providing a great opportunity to do a project under his supervision who guided me by providing with required material. His excellent guidance has been instrumental in making this project work success.

I would also like to think my parents for providing moral support and my friends who supported me through the whole duration by being a source of encouragement and inspiration.

Last but not least, I take this opportunity to express my sincere gratitude to the whole University of --------------- management staff for supporting me with infrastructure and lab facilities.



The main concept of this chapter is to give a basic overview of the new 802.11 standard, principles of operations, and some of the reasons behind some of the components of the standards. Due to limitations of wireless technology the WLAN has been easily became as bottleneck for communication. This WLAN service is capable to provide different priority to different applications, users to guarantee a certain level of performance to a data flow.

Background Information:

Under the leadership of Norman Abramson in 1970 the worlds first wireless computer network ALOHA net, with low cost ham-link radios was developed. Using electro magnetic radio waves the data is transported between computers in a local area network (LAN) with out any limitations set by hard wired networks cable and telephone connections. Modulation techniques carry radio waves and data is to be transmitted. The main propose of this WLAN is to use as an alternative to cables LAN in places where cabling connection is impossible. The wireless network will be operated under the Distributed Coordinate Function (DCF). In case of 802.11 networks there are two principles such as Inter-frame Spacing (IFS) and Random Back off Contention Window. In order to avoid the collision and to detect collision these principles are used. These also require wireless QoS.

Even in the early stages the 802.11e standers were adopted, there are many components with several optional components. There are four controller supports of QoS levels. They are given as

Platinum/Voice Ensures a high quality of service.

Silver/Best Effort Supports

Bronze/Background Provides

Gold/Video Supports High

Now a day the distribution of communication network can be observed in any of the technological field. Remote branches are being communicated with each other which belong to same organization. Office sharing, file transfers and data transfers are belong to the same organization. Modern communication network provides several new networks for organizational requirements. The major factors that are responsible for affective network system are reliability of the service, network availability, distance between the nodes and response time.

The maintenance of the WLAN is very high due to the high data rates and also use of typical architectures. As a result of this a high number of wireless local area networks from past few decades. With the help of interconnection of the branches across building network, Ad Hoc Networking and the nomadic access to the users was building up the network architecture. Number of vertical market, including health care, retail, manufacturing, warehousing and academia are popularly using wireless local area networks (WLANs). Hence taking all the above considerations mentioned factors are checked and effective network architecture has been designed in the present research work interacting with high end network software.

Importance of Research Work:

Under the research of several studies that record the measurements of radio waves used by WLAN have been conducted by some government. The co-existence of wired and wireless clients in a network environment is due to wide development of 802.11 WLANs. This kind of wireless network resembles the load problems and the performance issues in large sector. All this work of studies has shown that exposure to the radio waves used by wireless local area connections are substantially below the international safety limits. These radio waves provide enjoyments of television, radio as well as an increasing range of mobile communication and more benefits.

Present research results the design of the wired and wireless architecture for network analysis and the scenarios were presented that show the performance evolutions and the load. Wireless LAN deployment improves user’s mobility but it also brings a range of security issues that effect emerging standards and related technologies. Most of the companies, organizations and industries implement the wireless local area networks (WLANs) in various locations. This is because the users move from one place to the other. The measurement studies conducted at locations where WLANs were being used show that the technology operates substantially below the required international safety limits.

Field Research Complications:

Wireless local area networks are to be designed with proper planning and management. This is because it is accomplished through multiple inputs and multiple out put radio technologies, bonding adjacent 20MHz wide channels together for higher bandwidth 40MHz wide channels. If WLAN connections are not properly planned and managed can results in a tremendous waste of money and time failing to deliver on its promises.

The present research should improve the factors that evaluate the performance of the WLAN architecture by consuming less time and more efficiency. Also by reducing the management effort and by using architecture based on WLAN controllers, by increasing availability through Layer 2 redundancy, and by centralizing management and monitoring. Using OPNET simulator a deep analysis has been done with leader when the complication if find in the wireless LANs. Uplinks and Downlinks of the network should be provided at an intended time. The network has to be designed both in wireless and wired configuration. So connections between nodes should be checked properly on regular basis. Applications and profile configuration should be implied properly to improve the delay, loads, uplinks and downlinks etc.

State of Field:

Wireless local area network (WLAN) is based on a cellular architecture where the system is divided into number of cells. Even a wireless LAN can be formed by single cell, with a single access point, most installations will be formed by several cells where the access point is connected. Present research has been applied for several applications in the field of network architectures and computer networks. 802.11 have the family members such as 802.11a and 802.11b. The wireless LAN 802.11g may provide either high throughput like 802.11a or 802.11b compatibility, but not both at one time. Even these devices support a turbo mode that doubles the link rate at 108Mbps.

The maximum throughput may be attained at alternative at relative short distances with WLAN products, actual performance will decrease as the distance between wireless stations is increased. Environmental impact can also be observed on range and throughput. In these different types of environments the total coverage range will be significantly different. Present research work has been inspired from the ongoing computer network development and interactive sharing of resources between the pair of individual or group of work stations. Hence an effective way of architecture designing pattern has been implemented in the present work to design the physical network virtually.

Plan of project Document:


Wireless local area network (WLAN) technology has matured leaps and bonds in all areas driving the need for higher capacity to support new applications. With the centralized wireless LAN architecture, deployments are getting large and this is used in wireless ranges from connectivity to support critical business applications. Varying response time requirements have to be used in different applications. Changes in the configuration of wireless LAN can be dependent on the following factors such a RF channel, Transmit power, Applications, RF coverage, Firmware and Security improvements. Wireless LAN topology is a typically developed as an extension of an existing wired network as shone in below network.




Access point






Work station

Work station


A wired network is a dedicated level of network bandwidth such as 100 Mb/s Fast Ethernet is offered to the users computer where as in the case of wireless connections, an access point offers shared bandwidth, and therefore the capacity is measured as the number of users sharing each access points of bandwidth. In such applications a large amount of dad are transferred, such as email and browser-based applications, users are usually prepared to delays of a few seconds. If the nominal data throughput rate is high, the actual TCP throughput will not be very high unless the pocket loss rate remains low. With the introduction of IEEE wireless LANs a new factor comes into play that is the tradeoff between radio frequency (RF) coverage and bandwidth capacity per users. Quality of service mechanisms is necessary to ensure that there is an acceptable voice experience over the wireless local area network. Radio configuration of any AP should be left to Auto-RF, unless there are know issues at the site that preclude the effective use of Auto-RF. The configuration of this network can be performed under the IEEE 802.11b/g/n and IEEE 802.11a/n subsections of the wireless menu.

The important factors such as queuing delay, link utilization, response time and Ethernet delay have been given. The presented factors conclude the performance characteristics of the architecture. A pre descriptive evaluation of the network design architecture of the WLAN and wireless or wired network architectures has been dealt. The limitations are both with in the work and the up comings in the computers networking field has been suggested. Adding wireless to the network requires a good understanding between the coverage and capacity. So that it is possible to roam freely from one access point to another without affecting calls quality. Hence it is important to provide enough access points deployed so that voice over wireless handsets can roam to access points.


Business makes excessive investments in technologies and devices and need ways of simplifying communications for their networks and distributions of workforces to improve communication applications. The wireless local area network architecture is so designed in the present works ha to be undergone with several applications with the generalized parameters such as link utilization, response time, Ethernet delay and linking capacity. Communications over WLAN solution provide the means to flexible and productively manage communications in a variety of devices and mobile environments. The entire training academy is to be interconnected with ISP where training, management and financial tasks are being held in each of the stared campuses.



2.1 Introduction on Research

The project aim is to design a network and check the network performance by evaluating the network parameters such as queuing, response time, Ethernet delay and load. Network designer need to understand that how switches and routers switch traffic are to be designed a wired network and he also wants to understand how access points, wireless bridges and workshop bridges in order to design a proper WLAN. Even though it is difficult to improve the communication interface among agents in real traffic networks, each agent collects not only its own intersection information but also the four intersections around it. The Wireless LANs has to be designed to send the data at highest rate possible.

Wireless local area networks (WLANs) provide higher data but cover small smaller areas. Review of WLAN integration architecture and investigate two such architectures in the case of UMTS network is connected to a wireless LAN network at different integration points. The designing of this integration architecture were conducted through experimental simulation tests using OPNET. Present research have included several methods such as cross-layer design methods, wireless Networks, Channels Access methods, Ad Hoc networks and Quality of service (QoS). OPNET can also be used as research tool in Wireless local area connection. Due to this reference which have given an insight depth of knowledge of the techniques being implemented and the up-comings in the network architecture field.

Large number of inventions is made on these wireless local area networks. These are widely used in the present current works. The aims and objectives of the present research include the project goals have been discussions have been mentioned. According to these discussions about the different issues in the field the three scenarios and upcoming techniques. With this technique a wide range of information regarding the past and future of the computing network has been proceeding.

2.2 Research Journal Proceedings:

In the present research a brief overview of the current inventions in the field and the tools being implemented in different sections which has been given. All over many more papers have been referenced as the provided techniques improve the quality of the service and the way the network performance can be estimated.

2.2.1 OPNET as an effective networking Tool

OPNET service provides a unified, graphical visualization of large, heterogeneous production network, including devices, interconnectivity, traffic and status. This software can be applied in advanced networking educations providing a means to gain some practical networking insight. The solutions obtained from OPNET have been efficiently discussed in the above journal. The tool that favors for the quick evaluation of the performance has been also given. The OPNET have also created a profile for the back ground traffic on all network links. This project discuss deeper in to the assignment. Abstract concepts can also be understood by using the simultaneous processes.

2.2.2 Designing a network using OPNET

This paper presents show that network analyzer software has accuracy and same trend with independent data, real network and OPNET simulation tools. OPNET has been developed for network simulation and it is totally used as a robust and reliability simulation tool with higher investment. There is a network analyzer called as traffic analyzer. The functions of this analyzer has been given below,

Provides detailed statistics for current network.

Detect unusual levels of network traffic

Detect unusual packet characteristics

Identify packet destinations

Configure alarms and

Monitor bandwidth utilization

The OPNET is a system-in-the-loop module. It provides an interface for connecting live network hardware or software applications to an OPNET discrete event simulation. This includes ability, scalability and conformance testing of prototype network hardware, studying behavior of prototype applications on a simulated network infrastructure. A modeler Wireless Suite provides an advanced antenna modeling interface, enabling users to accurate specify antenna position and orientation patterns into network.

Current paper illustrates the process of optimization of the file sharing in the office environment. OPNET network life cycle approach consists of six phases such as prepare, plan, design, implement, operate and optimize. This concept will mainly concentrate on preparation, planning and proposal areas. The current project helps to regain the techniques and improves the quality for the current research. LAN topology also provides a clear idea of what are the nodes needs to be used in the topology. These are all to ne taken into consideration in the designing of network.

2.2.3 VoIP technique deployed using the network design simulator OPNET.

The paper explains the advantages of VoIP technique and its advantages in the massive developing world. Using OPNET the development of VoIP network has been started in the present approach in the initial stage. This network has been designed and tried to attain the IP calls and check the traffic of data sent and resaved also the delays. Dew to the impact of videoconferencing on the university network, VoIP has replaced the ISDN network of our research group, and cable access networks using the DOCSIS protocol. When the OPNET Modeler provides good support for design verification, this particular process is still a significant manual effort.

2.2.4 Wireless network design and issues with the effective detailing.

This paper explains the technical specifics, standards configuration, and layouts of the 802.11 wireless LAN implemented across Cisco Systems global corporate network. This also describe about the baseline design and configuration for the network. Access point configuration is very important in the connection of wired LAN or wireless LAN networks. It provides an interface for connecting live network hardware or software applications to an OPNET discrete event simulation. The above issues can be grouped together as an assignment problem. The connection window is exponentially increased; the risk of further collision is reduced. Implement a mechanism to differentiate between various traffic flows.

2.3 Discussion Phase