A wireless network is a communication facility that uses radio as their carrier or physical layer. The basic network consists of multiple stations communicating in a frequency range of 2.4GHz and 4.9GHz. Wireless networking is the state-of-art technology and an alternative to such networks which is hard wired by physical copper or fiber optic cables. Such a network has its advantages and disadvantages, compared to a wired network. The major advantage in having a wireless network is its mobility and elimination of cabling. Potential disadvantage is interferences due to weather, other wireless devices, or obstructions, like walls. It is gaining much demand in both home and business applications.

The two-way radio communication works on High Frequency (HF), Very High Frequency (VHF) and Ultra High Frequency (UHF) bands. The HF band ranges from 3 to 30 MHz, with VHF at 30 MHz to 300MHz band, while UHF belongs to a bandwidth of 300 MHz and 3.0 GHz.

Wireless Local Area Network (WLAN) is a wireless connectivity limited to local area networking. It utilises the same functions as that of a wired system, such as the Local Area Network (LAN). WLAN uses the spread spectrum technology on radio waves for communication between devices within a limited area. This facilitates the user to move around within the broad coverage area, and still remain connected.

Mobile communication implies communication through radio network. The most obvious example is establishing a wireless connectivity between a mobile network and the mobile handset or mobile terminals. The connection between the base stations to the core network of a mobile phone operator, in surprisingly high numbers, is realised through radio links. More-over, Wireless Local area Networks (WLAN) is gaining a major growth in the market today, with radio networking in office, at home and for public access. The base of Fixed Wireless Broadband is formed by the combination of radio link and WLAN technologies, being a move from proprietary into standard solutions. A further example could be set, when realising that the vendors have come up with a variety of solutions, where a single Internet connection can be utilised by more computers. This all have one thing in common - the computers need to be networked.

We presently see the advent of seamless wireless data and voice communication. The key capability of the next generation wireless communication would be Voice over Internet Protocol (VoIP), which forms a part of WLAN. The Quality-of-Service (QoS) is one of the planning issues in VoIP over WLAN. These issues are mainly, call control, network capacity, provisioning, architecture and others. For optimisation of this networking, the issues need to be looked into on a WLAN-by-WLAN basis. To meet the requirements of three main market segments is a challenge by itself in deployment parameters of WLANs. These market segments are:

1. Residential, small office and home office applications. 2. Private networking on VoIP WLAN. 3. VoIP over WLAN interfacing the public telephone network.

Following are the benefits of WLAN technology:

 There are situations where, wired connectivity between stations becomes costly, inconvenient or impossible. For example, cable-lay becomes a very costly proposition in a large building, where the stations are situated.

 In order to connect two buildings, separated by some physical, legal or financial hindrance, you can either ask your telecommunication authority to supply you with necessary links, or you can use WLAN application for the connectivity.

 WLAN can be used as a temporary measure for communication, which is in place for a specific time only. For example, such a network is suitable for trade shows or a convention, where laying cables for an Ethernet network becomes superfluous.

 In certain buildings, governed by building codes, laying cable becomes illegal. WLAN finds a perfect application in that situation.

 The WLAN technology is very attractive to home owners with several computers. A network could be set up without drilling holes in the wall and laying the cables for connectivity.

 A mobile laptop owner can always remain connected to the network, whether he is in the hallway, lobbies, cafeterias, classrooms or in a meeting.

 An easy way to remain connected to the internet at public places.

Etc

If you are in the middle of a public place, like, the airport, coffee shop, library or hotel, the chances are that you are already connected by wireless network. Increasing number of cities are using WiFi or 802.11 networking technology to provide low cost internet service to the residents. A time is coming when wireless networking will enable you to access internet just about anywhere anytime, without the use of wires. The mobile operators have started to provide such a wireless internet service, through a wireless network card, which goes in your notebook. This renders you mobile to any place you go and even to places in the world with a roaming account.

Security in wireless network can be divided into two parts: Authentication and Encryption. While authentication mechanisms can be used to identify a client in the network and the other-way-round, encryption makes it sure that it is not possible to intercept and decode data being transmitted.

There are two major primary security issues in wireless networking:

1. Access - Provide adequate access grants to the selected people who can use the network, without which, anyone in the vicinity could gain access into your network.

2. Privacy - Making sure that your network is not visible to anyone else. If this is not taken care of, anyone in the vicinity can watch everything you do on the network.

The total network is secured by administrator password, which is required to log into the devices, networked. The routers and access points in the network, cannot be accessed without such secured passwords. As soon as a WLAN is set up the first thing you want to do is to change the default password to something of your own. Without such a password the only way to access the network is to reset the total hardware to its factory default settings.

WLAN continuously and automatically broadcasts the network name, or the Service set Identifier (SSID). SSID is the name given to your WLAN, and all devices in the WLAN network uses this name to communicate to each other. This process makes setting up of wireless clients in the network extremely easy by locating your WLAN, and on the other hand. this makes your network to be visible to anyone operating within the range of your transmission. Turning off the SSID broadcast would make your network invisible to others.

To enable a secured network, disable the option of remote administration. Most of WLAN routers can be remotely administered, via internet. This feature should only be used, if the network lets you define a specefic IP address or a range of addresses, which would be allowed to access the network administration. It is advisable to keep the remote administration option turned off.

It won't be right to say that your network is completely secured. It is always possible for 'snoopers' to get into your traffic. Some network have been built and managed with more security built into it, but, for both LAN and WLAN, we often ask ourselves - how secured are we?