Computers invaded us, and won. The very nature of businesses today demands mobility and instant, anywhere access to critical information. While the Internet has given us this much required data mobility on a global scale, the same does not hold true within our own offices. Unfortunately, the desktop has been the ruling party so far, and mobile devices are only just gaining popularity.
We tend not to realise how chained we are to our seats at work. Executives jet across the world, access their e mails in airports worldwide, meet with clients in hotels and restaurants, and download presentations; yet, within their own offices, they are confined to a 4 x 6 foot space called a cubicle and all because of a short wire with an RJ45 connector on one end. Networking, the bane of mobility!
vying with Wi Fi
If this were the company awards ceremony, we would have numerous distinguished speakers gushing superlatives, introducing the persona that single handedly revolutionised mobile computing. Yes, that's perhaps the most apt introduction to WiTi. Without it, every mobile device, from laptops to PDAs, would be nothing more than external hard drives absolutely useless on their own, but great for transporting data from one network to another.
But should all businesses set up a Wi Fi network? If only it were that simple! New companies have no problem deciding: WiTi is the way to go the setup is quick, easy and affordable, and shifting offices is as easy as packing and unpacking the equipment. However, existing businesses really have to weigh the mobility offered against the costs. If you have a huge inventory management setup, and lots of employees using equipment such as laptops and barcode scanners, you should seriously consider WiTi as an option.
I'm Sold. What Now?
You need to do a site survey, and then decide upon the number of access points you need in order to be able to provide seamless network coverage. You also need to keep in mind that there's no such thing as a true wireless LAN (WLAN) with no trace of wires. Your servers and access points need to be connected via a regular wired LAN to give them the connection
stability they need. You also need to make sure that you overlap the access point coverage areas sufficiently to offer the maximum possible network speeds to your users.
You will obviously need a lot of Wi Fi enabled equipment to make use of your WLAN setup, and if this equipment isn't already deployed, this cost needs to be factored in as well.
The Site Survey
A proper Radio Frequency (RF) site survey is a requisite, and it can be done in two ways as a task left to the firm you hire to deploy WLAN, or done by your in house IT deployment team. Of course, smaller businesses could have a systems engineer using one access point and a laptop to set up and walk around the site checking signal strengths. Whatever the case, your WLAN deployment needs planning, as anything, from a wall to machinery can disrupt the wireless signals.
You must also consider actual working conditions when planning your WLAN setup. For instance, a warehouse where a site survey is done when there is less activity and no goods are stored; after deployment, however, you may find that running machinery, or even piled up goods, can interfere with the wireless signals.
You should recognise the dynamics of your environment. As explained above, a warehouse may require different deployment tactics than a regular office. In an office, users will be at their desks most of the time. However, a regular office will also have cubicles, walls and other obstructions that will adversely affect the signal.
A Seamless WLAN
A seamless WLAN setup is one where users can stroll across the covered area, and at the same time have constant access to the network. This is easier said than done, and is a lot more complicated than just setting up access points to cover the desired area. The 802.11 specification offers 14 different channels, or frequencies, at which access points can be set. The problem is, these frequencies are too close together a difference of just five MHz between channels and interference is caused, To overcome this interference, the three standard channels used are 1, 6 and 11. To offer seamless roaming around the coverage area, you will need to ensure that any three neighbouring access points are configured to run on these three different channels.
This is easy when setting up a two dimensional coverage area, say, on a single floor. However, when you have to do this for a building, with access required on multiple floors, sketch a 31) view of your coverage area and make sure that all access points on all the floors are set to operate on different channels. A good blueprint of your office building will come in handy. You will also need a wireless network monitoring tool to test the actual setup.
Bandwidth
Every network needs to provide its users with the bandwidth they require, and this is where wired LANs definitely have an edge. A standard wired LAN will offer your users a theoretical bandwidth of 100 Mbps, almost double the theoretical bandwidth of 54 Mbps for a WLAN. However, just as you do not expect the full 100 Mbps bandwidth from wired LANs, you cannot expect anywhere close to 54 Mbps for WLANs.
The most logical calculation is to halve this bandwidth and divide it by the number of users you plan to provide access to in a given area. For instance, if there are 10 users on a WLAN per access point, each user will get 27/10 = 2.7 Mbps of maximum bandwidth, which will suffice for most. Only users who constantly transfer large files to and from a server will need more bandwidth. Take into account this user density factor when deploying your WLAN.
Security
Now that you have your WLAN plans in place, your biggest concern will be security. No one wants to have their private office LAN visible to the outside world. Apart from people snooping around your LAN, you will also be put at risk by worms and viruses from neighbouring WLAN setups or wireless devices. What you need to do is ensure that your WLAN is as secure as it can be.
First of all, get a WLAN monitoring tool. In case your system administrators largely use Linux, then 'kismet', the default WLAN monitoring tool for Linux, will do the job. Windows users can choose from a huge list of commercial as well as free tools.
