Introduction
1.1 Background Of The Study
Recently wireless local area networks (WLANs) have emerged as flexible communication systems, which have been implemented as an extension or alternative to a wired LAN within buildings. Using electromagnetic waves WLANs transmit and receive data over air interface, minimizing need for wired connection; thereby it enables user mobility in covered area without losing connectivity from the backbone network. The system implementations vary from simple peer-to-peer connection between two computers to cover entire buildings by many transmitter/receiver devices − access points (AP), which are connected to the wired network.
Most of the recently used WLAN systems are specified in IEEE 802.11 standard. The IEEE 802.11 standard is divided into two main layers: the Medium Access Control layer (MAC) and the Physical Layer (PHY). These two layers allow a functional separation of the standard and, more importantly allow a single data protocol to be used with several different RF transmission techniques.
WLAN systems mainly work based on these standards:
- 802.11b (802.11HR) − DSSS at 2.4 GHz with 1, 2, 5.5, and 11 Mbps data rates,
- 802.11g − OFDM at 2.4 GHz with 1, 2, 5.5, 11, and 22 Mbps data rates,
- 802.11a − OFDM in 5 GHz band with 6, 12, 18, 24, 36, 48, and 54 Mbps data rates, and
- HiperLAN2 − OFDM in 5.15-5.35 GHz and 5.725-5.825 GHz bands, similar to the 802.11a PHY (with varying convolution codes).
The indoor signal propagation differs from an outdoor case particularly in distances and in variability of the environment. Due to the multipath propagation (multiple reflections, diffractions and scatterings of electromagnetic waves from surrounding objects) the radio signal distortions and propagation losses (fading) occur.
For a small network in a limited area, only manufacturer’s information on the coverage range is sufficient to deploy the APs. For a larger network, a more accurate deployment procedure is required to ensure sufficient coverage and network functionality (bit rate, capacity, interference, etc.). Basically there are two approaches. The first is based on a site survey with a lot of measurements and experimental decisions. The second method comprises of software planning using propagation models.
Wireless networks have significantly impacted the world, since their initial deployment. Wireless networks have continued to develop and their uses have significantly grown. Cellular phones are nowadays part of huge wireless network systems and people use mobile phones on a daily basis in order to communicate with each other and exchange information. Recently, wireless networks have been used for positioning as well, in order to enable the provision of location-oriented services to the end-user. Different types of measurements available during standard network and terminal operation, mainly for resource management and synchronization purposes, can be employed to derive the user’s location. With these numerous uses of wireless network, this project will focus on resources sharing dedicated network. A professor at the University of Hawaii, Norman Abramson developed the world’s first wireless computer communication network, ALOHAnet (operational in 1971), using low-cost ham-like radios. The system included seven computers deployed over four islands to communicate with the central computer on the Oahu Island without using phone lines. WLAN hardware initially cost so much that it was only used as an alternative to cabled LAN in places where cabling was difficult or impossible. Early development included industryspecific solutions and proprietary protocols, but at the end of the 1990s these were replaced by standards, primarily the various versions of IEEE 802.11 (in products using the Wi-Fi brand name). An alternative ATM-like 5 GHz standardized technology, HiperLAN/2, has so far not succeeded in the market, and with the release of the faster 54 Mbit/s 802.11a (5 GHz) and 802.11g (2.4 GHz) standards, it is even more unlikely that it will ever succeed. In 2009 802.11n was added to 802.11. It operates in both the 2.4 GHz and 5 GHz bands at a maximum data transfer rate of 600 Mbit/s. Most new routers are able to utilize both wireless bands, known as dualband. This allows data communications to avoid the crowded 2.4 GHz band, which is also shared with Bluetooth devices and microwave ovens. The 5 GHz band is also wider than the 2.4 GHz band, with more channels, which permits a greater number of devices to share the space. Not all channels are available in all regions.
A wireless local area network (WLAN) links two or more devices using some wireless distribution method (typically spread-spectrum or OFDM radio), and usually providing a connection through an access point to the wider Internet. This gives users the ability to move around within a local coverage area and still be connected to the network. Most modern WLANs are based on IEEE 802.11 standards, marketed under the WiFi brand name. Wireless LANs have become popular in the home due to ease of installation, and in commercial complexes offering wireless access to their customers; often for free. New York City, for instance, has begun a pilot program to provide city workers in all five boroughs of the city with wireless Internet access. Likewise, Muritala International Airport, Lagos has free wireless internet access for passenger travelling.
1.2 Statement Of Problem
The basic issue addressed in this project is to study the feasibility and characteristics of wireless local area networks. The success of current wireless LANs under these conditions will lead us to use them as high rate outdoor wireless data networks.
Wireless networks can provide communications to both fixed and mobile users without any need of using data cables and can provide substantial flexibility to both end-user and service provider.
The use of current cellular/PCS high data rate services for data networking is not economically feasible due to high usage costs. Wireless local area networks have been designed and used for mostly indoor applications. The possible use of these wireless LANs for high mobility outdoor applications, such as, telemetry, traffic surveillance, rescue operations, and outdoor data networking can provide reasonably high data rates at minimal operational costs. These attractions led us to investigate the feasibility and operational characteristics of current wireless LAN standards in high mobility outdoor environments.
Most of us have become accustomed to the limitations that come with a wired network. When we want to check our email or print a report we find ourselves confined to a certain location or cramped space. In the past few years, the growing popularity of wireless communication has caught the attention of corporate, manufacturing, and academic settings. Wireless network technology has proven it can deliver the benefits of a wired network with the added benefit of computing freedom and share resources.
1.3 Motivation
There is existing LAN connection but there are some features its lacking which inspired me to implement this project. There is no share printer/resource; no dedicated network irregularities etc., upon completion of this project, all of these drawbacks would be taken care of.
1.4 Aims And Objectives
The aim of this project is to design a dedicated wireless local area network (WLAN) for Dorben Polytechnic Abuja, for file and printer sharing over the network. To achieve this, there are steps to take, which are: installation of wireless router, setup the router and preference, installation of printer and integrate the printer to the wireless router.
1.5 Purpose Of The Study
- To save cost of buying printer machine for each workstation.
- Mobility and flexibility, which is any eligible staff moves around with his /her laptop, can still print file within the coverage area.
1.6 Significance Of Study
The important of this project are many but few will be mentioned. Firstly, let consider that in department of School of Science and Technology every workstation required printer machine which will cost the school huge among of money, cost of maintenance and occupy more space. But, by the time this project will be implement a printer machine can be share over a dedicated wireless local area network for department of school of Science and Technology.
1.7 Terminologies
1.7.0 Router:
It is a specialized network device that determines the next network point to which to forward a data packet toward its destination.
1.7.1 Internet Protocol Address (IP ADDRESS):
It is a numerical label assigned to each device (e.g., computer, printer) participating in a computer network that uses the Internet Protocol for communication. An IP address serves two principal functions: host or network interface identification and location addressing. Its role has been characterized as follows: “A name indicates what we seek. An address indicates where it is. A route indicates how to get there.
1.7.2 Protocol:
It is a set rule governing how to communicate over a network.
1.7.3 Dualband:
It is a communication device (especially a mobile phone) that supports two radio frequency bands.
1.7.4 Radio Modems:
These are radio transceivers for serial data communications. They connect to serial ports RS232, RS422/485 and transmit to and receive signals from other matching radio (point to point) or radios (multi drop) network. Wireless Radio Modems are designed to be transparent to the systems they operate within.
1.7.5 Network Switch:
This is a computer networking device that connects devices together on a computer network, by using a form of packet switching to forward data to the destination device. A network switch is considered more advanced than a (repeater) hub because a switch will only forward a message to one or multiple devices that need to receive it, rather than broadcasting the same message out of each of its ports.
1.7.6 Hub
It is a device for connecting multiple Ethernet devices together and making them act as a single network segment. It has multiple input/output (I/O) ports, in which a signal introduced at the input of any port appears at the output of every port except the original incoming.
1.7.7 Network Bridge:
It is a network device that connects multiple network segments. In the OSI model bridging acts in the first two layers, below the network layer. There are four types of network-bridging technologies: simple bridging; multiport bridging; learning, or transparent bridging; and source route bridging.
1.7.8 Network Antenna:
It is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver. In transmission, a radio transmitter supplies an electric current oscillating at radio frequency (i.e. high frequency AC) to the antenna’s terminals, and the antenna radiates the energy from the current as electromagnetic waves (radio waves). In reception, an antenna intercepts some of the power of an electromagnetic wave in order to produce a tiny voltage at its terminals that is applied to a receiver to be amplified. An antenna can be used for both transmitting and receiving.
1.7.9 IEEE (Institute of Electrical and Electronics Engineers):
This is a professional association with its corporate office in New York City and its operations center in Piscataway, New Jersey. It was formed in 1963 from the amalgamation of the American Institute of Electrical Engineers and the Institute of Radio Engineers. Today it is the world’s largest association of technical professionals with more than 400,000 members in chapters around the world. The standard upheld for the design of the project was constituted by the professional body called the IEEE standard.
