What is wireless networking?

Wireless Networking, sometimes known as Wi-Fi, or by the transmission protocol used of 802.11b, 802.11a or 802.11g, allows you to connect computers on a network or to the internet without cables.

How? Wireless Networking is a wireless technology like a cell phone. Wireless enabled computers send and receive data indoors and out; anywhere within the range of an wireless access point. And the best thing of all, it's fast. In fact, it's several times faster than the fastest cable modem connection. A Wi-Fi CERTIFIED PC Card or similar device means that you will be able to connect anywhere there are other Wi-Fi CERTIFIED products whether you are at home, the office or corporate campus, or in airports, hotels, coffee shops and other public areas equipped with a Wi-Fi access available.

There are four wireless-networking standards available depending on your requirements:
1. Wi-Fi (802.11b), or Wireless Fidelity which is also known as 802.11b is the corporate choice and has a suitably wide range for use in big office spaces. Wi-Fi (802.11b) is currently the most popular and least expensive wireless LAN specification. It operates in the 2.4GHz radio spectrum and can transmit data at speeds up to 11Mbps within a 30m range. It can be affected by interference from mobile phones and Bluetooth devices which can reduce the transmission speeds. It is the standard feature of many wireless laptops including the new Centrino-based models.

2. 802.11a, has a couple of advantages over Wi-Fi. It runs at a less-populated frequency (5.15GHz to 5.35GHz) and is therefore less prone to interference. Its bandwidth is much higher, at a theoretical peak of 54Mbps. Even though actual throughput is closer to 22Mbps. Some manufacturers offer proprietary modes that can push throughput a little higher. Its main problem is its shorter range: 15m compared to Wi-Fi's 30m, forcing you to buy more access points to ensure full coverage. It is also more expensive not compatible with Wi-Fi (802.11b). There are dual band cards and access points available from some manufactures that automatically switch between the two to maintain a connection.

3. 802.11g is the latest standard and promises to be the most popular format in the furture. It combines the speed the 802.11a with the backward compatibility of 802.11b. It has the same longer range of 802.11b but in the same way it can be affected by interference.

4. Bluetooth is a somewhat different standard from Wi-Fi or 802.11a, offering much more flexibility but on a smaller, 'personal area network' scale and primarily is being seen as a replacement for I.R (Infa Red) and wireless connection to Bluetooth enabled electronic devices. Its actual throughput is only 300Kbps, and its range around 10m. But unlike Wi-Fi and 802.11a/g, which require adapters, routers, gateways, access points and synchronised setup schemes to connect devices, any devices with a Bluetooth radio and antennae or Bluetooth enabled can speak to each other with little or no preparation.

Wireless networking basics:
When upgrading to wireless a network the overall layout can be a bit confusing. If you are not overly familiar to network topology, here we will hopefully be able to make a bit easier to understand what you need to add to your existing network setup to give you a wireless network capability.

Add wireless network capability to your wired network:
To give your existing network a wireless capability, all you need to do is add a wireless access point to your network switch/hub and wireless PCMCIA cards in your laptops or PCI cards in your PC/Mac desktop computers. Once this is done the computers that use the wireless cards are now connected to the switch/hub in the same way as if they used a normal network cable. One of the major benefits of this is that you don't have all the hassle of laying new cables in to an existing office setup. Depending on the wireless access point used, you can have up to 32 or more wireless computer users per access point, without having to buy a bigger switch/hub with more ports.

With the advent of widespread broadband access to the Internet, many offices could use this opportunity not only to upgrade to a permanent Internet connection but also to go wireless at the same time. In Figure .4 the existing network has been connected to the Internet via a ADSL modem router together the wireless access point. Now every computer on the network whether it is wired or wireless would have a potential permanent Internet connection. If you have a cable Internet provider like NTL or Telewest then you would use a cable DSL router without a built in modem.

Many businesses that have gone with the BT business broadband setup will use the four port router that came as part of the package. This allows you to connect up to 4 computers to the Internet. You can see that by adding a wireless access point to one of the ports of the router you can now give wireless Internet access for up to 32 or more users per access point. This would be ideal for anyone with an existing BT broadband setup that did not want to change the router but wanted to add wireless and or more users that could access the Internet.

Choose a Flavor of Wi-Fi:
In order to ensure interoperability, focus on using Wi-Fi certified products. Your choice should be 802.11b/g (2.4GHz), 802.11a (5GHz), or dual-band that includes both 802.11b/g and 802.11a.

For most applications, 802.11b/g will suffice. You'll have up to 54Mbps data rates with fairly good capacity. The slower (11Mbps) 802.11b is interoperable with nearly all WLAN enabled devices, and probably considerably cheaper if you can even find them anymore.

The need for 802.11a-only networks is fairly rare, especially within a home office setup. If you plan to make use of special 802.11a applications (there aren't many yet) or just want to position yourself for possible future 802.11a applications, then go with the more expensive dual-band approach. Some companies refer to these products as "tri-mode" because they include all three technologies 802.11a, 802.11b, and 802.11g.

Purchase a Wi-Fi Router:
Something to keep in mind is that you need a Wi-Fi router, not an access point. Unlike an access point, a router supplies the necessary network layer functions, such as network address translation and dynamic host configuration protocol. This enables multiple devices on the network, such as PCs, laptops, PDAs, and printers, to share the single official IP address (define) that a broadband service provider supplies. If you connect an access point directly to the broadband modem, usually only one device on your network will receive an IP address the access point itself.

If you happen to have an access point lying around, you can still make use of it. Simply purchase an inexpensive Ethernet-based router and interconnect it between the access point and the broadband modem. The Ethernet router will then take care of the NAT and DHCP functions.

A single router (or access point) is generally enough to fully cover most homes. For example, a single dual-band 802.11a/b/g router provides full coverage and respectable performance throughout an entire two story house with a finished basement.

Centralize the Router Installation:
Install the router within reach of the broadband modem, using Ethernet patch cable. If you haven't already had a broadband connection established, consider having it installed somewhere central to the areas where you'll be using the wireless network. This is typically the center of the home or a small office.

Ideally, install the broadband connection in the same room as any device (such as a printer) that you want to connect to one of the Ethernet ports provided by the router. With two floors, choose installation on the floor where you'll be using the network a higher percentage of the time.

Default Settings Gets Things Going:
Default configuration settings on the router will enable users to immediately associate and begin accessing broadband Internet services. Most routers have DHCP already enabled for obtaining the official IP address from the ISP through the broadband modem, and DHCP and NAT are ready on the router to hand out private IP addresses to user devices.

This truly makes the router installation straightforward. Normally, all you have to do is plug in the router and users will readily associate and have access to Internet applications. Be sure, however, to follow vendor-specific installation instructions.

Configure Security Mechanisms:
By default, most routers don't have any security enabled, which means that all data packets are sent unencrypted in the clear. A unscrupulous person sitting in a car outside your home or office, for example, can wirelessly monitor these transmissions and see e-mail contents, user names, and passwords. In addition, unauthorized users can access files on computers inside the home and use the Internet through your broadband ISP connection.

If you don't want this to happen, then activate encryption supplied within your router. Wired equivalent privacy, WEP for short, is better than nothing, but take advantage of the more advanced Wi-Fi protected access if it is available.

Be Weary of RF Interference:
For the most part, RF interference is not a significant problem in homes or even small offices. Microwave ovens and cordless phones, however, propagate RF signals that can cause data frame retransmissions and resulting delays with WLAN users. For example, a microwave oven in operation can dramatically slow down Web page loads when 802.11b/g users are within ten feet or so from the oven. If this is an issue, try setting the router to channel 1, which generally stays clear of microwave oven interference.

With 2.4GHz cordless phones, the damage goes both ways. When the phone is in use, 802.11b/g users may experience a drop in performance. Also, poor sound quality will likely persist through the phone.

A problem is that there's no optimum channel for the router when trying to minimize cordless phone interference with 802.11b/g WLANs. Ideally, you should use either 900MHz or 5GHz cordless phones.

If you want to discuss your needs or consider to get professional help on setting up, troubleshooting or upgrading a wireless network for your home or business, please call 0207 516 1077 or email info@computerdoctor.co.uk. You can book a qualified WIFI technician to visit you at home or in your business premises at a time and date convenient to you. We can also provide all the necessary wireless equipment if you do not have them already.