The majority of households in the UK, Europe and the US will have a connection to the Internet, and in most cases will have a device known as a Wireless Router to provide that connectivity for at least 1 computer device. In most cases the Wireless Router will be used to connect multiple devices from a local WLAN to the Public Internet.
Before we specifically describe a Wireless Router, it is probably best to describe the role of a Router in a data network. A Router’s role is to read the logical IP Address on packets and determine which network or sub network those packets need to be delivered to. A simple way to look at a router is to compare it to a postal sorting office where letters have their post codes or zip codes checked to determine which area of the country the letter is destined for. In the UK, the first part of the postal code determines the general area such as an area of London or Manchester, and the second part determines an actual street or road. An IP Address, when coupled with a network mask does almost the same thing, but instead of a Geographical area, the router is able to determine a specific area of a network.
A local router which is attached to a Local Area Network or Wireless Local Area Network acts as the local postman by determining the physical MAC Address of a device so that it can deliver packets to the correct computer device.
In order to connect to the Internet we normally need a modem that runs the same protocols as the Service Provider Access Network. In most cases we will be using either an ADSL Modem or a Cable modem depending on who our service provider is.
A wireless Router will normally combine the functions of a modem, a router and a wireless access point, and provide not only wired connectivity to local devices by means of an Ethernet cable, but also provide the option of connecting to local devices by means of a wireless technology specified in the IEEE 802.11 Wireless standard. The IEEE 802.11g standard allows for local wireless connectivity at 54Mbps within the 2.4Ghz ISM frequency bands. The IEEE 802.11n standard was ratified in 2009 and provides for enhanced data rates up to 300 or even 600Mbps and incorporates the MIMO ( Multiple Input Multiple Output) technology which requires the use of additional antennas. The channel width is also doubled from 20Mhz wide channels used with previous versions of the standard to 40Mhz. Routers running the 802.11n standard with MIMO are normally a little more expensive due to the cost of the additional antennas.
The home Wireless router will also act as a DHCP (Dynamic Host Configuration Protocol) Server, so that local IP Addresses can be automatically served up to local computer devices, doing away with the need to manually configure IP parameters on each an every local device. Another protocol running on the wireless router with be NAT (Network Address Translation), which translates locally routable IP Addresses to Globally routable IP Addresses needed on the Internet. This means we can all use the same local IP Addresses on our LAN or WLAN to communicate locally, but use the Global IP Address supplied by our Service Provider when accessing the Internet. The router translates from local to global on the way out and the reverse as packets are routed towards the local network needs a degree of security, particularly when connected to the Public Internet, otherwise anyone globally could have access to your network. The router will provide this security by having a built-in Firewall function. Wireless networks have additional security issues because of the fact that anyone within range of your wireless network, who has a wireless access point or device could join the network and therefore eavesdrop on data conversations, or worse still access a computer device and steal or corrupt information. For this reason a number of Wireless security protocols have been developed to protect the WLAN.
The first wireless security protocol was WEP (Wireless Equivalent Privacy) which uses an Authentication and Encryption key normally of 64 or 128 bits in length to protect the data as it traverses the wireless lan. WEP keys can easily be broken by someone determined enough to do it and programs are freely available on the Internet for this purpose. For most home users WEP may be sufficient, but as you don’t necessarily know who your neighbours are and their intentions, it is better to protect your local wireless network with a more advanced security protocol. WPA (Wi-Fi Protected Access) uses much stronger encryption than WEP and should be used in preference to WEP when necessary. It is important to note that most wireless routers come packaged with wireless security turned off, so it is up to the consumer to determine the level of security required and to configure the parameters when originally setting up your WLAN. If you are not technically minded then find a friend of relative that has some knowledge and choose the strongest protection available on the device, which will normally be WPA.