Search Blog Content

Tuesday, January 15, 2013

What to Look for in a Wireless Access Point


Wireless networks have been one of the technologies that have revolutionised data networking, both for the home user and business networks. A wireless network in the home gives us mobility so that we are not tied to a single location within the home. Modern wireless routers have a wireless access point built in and usually give the flexibility of allowing both wired and wireless connections.
So what should we look for when choosing a wireless access point? There are many models to choose from, offering a wide range of supporting protocols and standards. They also come within a wide price range depending on the networks they are designed to support. Prior to the introduction of Wireless Access Points, early wireless networks were referred to as Ad Hoc networks, because two or more wireless-enabled devices communicated with each other when both within range, rather like a Bluetooth network. Ad Hoc networks are fine when there is a common theme such as gaming, but are not particularly good for general Internet connections. Wireless networks using Wireless Access Points have a number of distinct advantages, such as the ease at which they can be secured given the right security protocols and another advantage is the ability to have multiple access points supporting multiple WLANs all connected to the same wired Local Area Network.
Wireless Access Points have many diverse applications these days, and these range from providing wireless access to a corporate LAN, and when multiple access points are used then roaming becomes possible. A WLAN Controller is normally used to manage a group of APs within a LAN environment. Some Wireless Access Points are used to allow the public to connect to the Internet such as in hotels, coffee shops and even supermarkets. It is wise when using these public wireless networks to have good security on your PC as security is not a great feature of these applications. Access points used in this way are often referred to as wireless hotspots.
The common wireless standard is the IEEE 802.11 standard which has 3 main categories, namely 802.11a, 802.11b and 802.11b. The IEEE 802.11a standard is designed to operate within the 5Ghz UNII wireless band, while the IEEE 802.11b and g standards operate within the 2.4Ghz ISM band. The IEEE 802.11g standard can provide speeds of up to 54Mbps and is backward compatible with the IEEE 802.11b standard. With diversity antennas supporting the IEEE 802.11n standard, speeds of up to 300Mbps can be achieved. Don't let these speeds fool you as a lot of the bandwidth is taken up by the sophisticated overhead associated with these networks. Typically a 54Mbps connection will give you a TCP/IP throughput at a maximum of 25Mbps.
A very important consideration when deploying a WAP is security in the form of authentication to ensure only trusted client devices associate with the access point and encryption to ensure any data you send across the radio environment is secure from eavesdropping. All the client devices are sharing the same wireless environment and have access to that network through the use of CSMA/CA (Carrier Sensed Multiple Access with Collision Avoidance). Any wireless client within range of the radio signal will be able to detect the presence of a wireless access point and may try to associate with it. When the right security methods are employed, only clients with the correct authentication credentials will be able to associate and then have access to the radio channel.
When choosing a wireless access point check the security features that are supported. The older less secure methods include WEP (Wired Equivalent Privacy) with normally 64 or 128-bit encryption keys. These methods can be compromised by individuals who have the knowledge. You should at least be looking for device that supports WPA (Wi-Fi Protected Access), or better still the more advanced WPA2 standard. In the corporate environment a WAP is often protected by means of the IEEE 802.1x standard which uses a server to authenticate clients before they are allowed access. The Ethernet switch to which the access point is attached will challenge a device and forward information received to a server like a RADIUS (Remote Access Dial In Use Service) server, who will inform the switch whether access should be granted or not.
When determining which access point you should buy, you have to firstly decide on what it is to be used for. How much throughput do you need for your applications? Will a 54Mbps network be enough or maybe your would like or need to have the IEEE 802.11n standard running at 300Mbps. Does the wireless access point need to be mounted on a wall or ceiling, or is it just to be positioned on a desktop? Will the existing antenna provide sufficient gain for your needs, or does the antenna need to be detachable to allow a more suitable antenna to be used. How and where will the WAP connect to the wired network and what level of security will you need?
Finally, something we haven't discussed so far, can you use an access point with a power adapter or does the device need to be powered over the network from a PoE (Power over Ethernet) Switch or even a Power Injector?
Does the device you have chosen have a simple intuitive Graphic User Interface for configuration and monitoring, or do you need configuration skills because the device is configured from a command line interface?
The more features and functions you need with your WAP, the more the unit is likely to cost you.
This article on Wireless Access Points was written by David Christie, MD at NSTUK Ltd, Website
Article Source:

Article Source:

No comments:

Post a Comment