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What to Look For in Wireless networking: Range, Speed and Standards.

What to Look For in Wireless networking: Range, Speed and Standards.

Not sure what you’re doing in your wireless card shopping? Want to make sure you’re buying the right thing but just have no idea what it is you’re looking for? Well, you’ve come to the right place. When you’re looking to buy a wireless network card, I can tell you right now that you’re looking at three key issues: range, speed, and standards.

A Typical Specification.

This is a typical specification for a Linksys wireless PCMCIA laptop card:

11 Mbps high-speed transfer rate; interoperable with IEEE 802.11b (DSSS) 2.4Ghz-compliant equipment; plug-and-play operation provides easy set up; long operating range (up to 120m indoor); advanced power management features conserve valuable notebook PC battery life; rugged metal design with integrated antenna; compatible with virtually all major operating systems; works with all standard Internet applications; automatic load balancing and scale back; model no. WPC11. (source: amazon.com).

Now, some of those things can be pretty much ignored. Really, ‘virtually all major operating systems’? That means nothing. The reason I’ve put it here, though, is so you can see which things are important to keep an eye out for.

Range.

See where it says ‘up to 120m indoor’? This tells you that the maximum range of the wireless card you’re looking at is 120 metres — that’s what it would be if everything was perfect. In practice, thick walls and interference can reduce this number by as much as 90%.

Without enough range, your wireless network is going to be pretty useless. It’s not much fun having no wires when you have to keep all the computers in the same room to get them to connect to each other.

As a rule of thumb, unless your walls are made of drywall or wood, it’s best to buy about four times the strength you’d think you’d need. Even in perfect conditions, get twice as much, to be safe. If you need to convert from metric to imperial units, remember that there are 30 centimetres (0.3 metres) in a foot and about 2.5 centimetres in an inch — you shouldn’t have too much trouble.

Speed.

Do you see where it says ‘Mbps’ in that description? That number is the speed of the wireless connection. 11 Mbps is about one and a half megabytes per second — to convert megabits (Mb) to megabytes (MB), just divide by eight. 802.11b wireless cards all have a speed of 11Mbps, while 802.11g ones run at 54Mbps — the next generation will be even faster.

Speed is important to your wireless network because it’s going to directly influence how long you have to wait for things like files to transfer from one computer on the network to the other. It is less important for Internet use, however, because there are currently very few Internet connections running at speeds over 11Mbps — it’s really as much as you need, at least for now.

Standards.

Somewhere in the specification of what you’re looking at, you should see the number ‘802.11’, followed by a letter ‘a’, ‘b’ or ‘g’. This is the standard that the wireless device conforms to, and tells you whether you will be able to use it with your other wireless devices.

Basically, 802.11b and 802.11g are compatible with each other. 802.11a is not compatible with either and is quite a bad standard all round, so you shouldn’t buy 802.11a. Out of b and g, b is cheaper but slower, while g is more expensive but faster. It’s worth considering that adding a b-speed device to a network that has g-speed devices will often slow the whole network down to b-speed, making the g-devices pointless.

If your wireless device doesn’t conform to the right standards, it’s not going to be much good to you. I often see naive people bidding for used wireless equipment on eBay, not realising that it’s going to be terribly slow and not work with any other equipment they might have. Always make sure that you check what standard the wireless equipment is — if you don’t know the 802.11 letter, don’t buy it!

Ad-hoc or Access Point – Network Structures Explained.

Ad-hoc or Access Point? Network Structures Explained.

What happens to many people is that they’re just about to buy some wireless equipment, and then they have a sudden realisation — they have no idea how their network layout is going to work with a wireless connection. Well, there are a few things you need to think about when you decide how you’re going to connect up your computers with all that great new wireless stuff.

Ad-hoc Networks.

Ad-hoc networks are the ones your wireless devices create more-or-less on their own — they are also known as peer-to-peer networks. In an ad-hoc network, each computer on the network acts as an equal ‘peer’, with each one sending data to any other. This arrangement is most often used in place of a real LAN, to allow employees in a company, for example, to exchange files. You can create ad-hoc wireless networks between any computers that have wireless equipment — access to the Internet is not required.

These networks work using something called an ‘SSID’ (Service Set Identifier). Essentially, this is the network’s name, decided on the computer that was the first to connect to the network (yes, a network consisting of just itself). The other computers that connect to the network can then simply connect by finding the network with the name (SSID) they want.

This is powerful. You can put your wireless-enabled laptop next to a friend’s, and the two computers can create a little network for themselves on the fly. Thanks to the way wireless networking works, they keep the connection even if you move them around — the only thing that will force the computers to disconnect from each other is if they go out of range. For many people, this spells the end of messing around with CDs and floppy disks — they can finally use their laptop just like a briefcase, carrying everything from one place to another.

Arriving somewhere with your laptop and being automatically included in the wireless network also gives you access to shared resources, such as printers. Imagine being able to take your computer to somewhere where there’s a printer, press print, collect the document and walk away again. Ad-hoc networking makes this a reality.

Access Points.

An access point, on the other hand, is a way of connecting your ad-hoc wireless network to a real, wired network. Note that this network could just be a LAN, or it could be the entire Internet. There are hardware access points and software ones, with either kind allowing you to connect your wireless device to a wired network. Internet Connecting Sharing, for example, is a software access point to the Internet, while a wireless router is a wired one. If you have wireless access at your office, the chances are it is provided as a wireless access point to the wired network, to let people bring in wireless devices and connect them to the office LAN.

A network that contains an access point is sometimes called an ‘infrastructure’ network, as opposed to an ad-hoc one. It’s worth remembering, though, that part of the infrastructure network still consists of the ad-hoc network between the computers — they can still communicate just the same as they could before.

If you think about it, you can see that the access point structure allows you to create a series of networks, all interconnected. The Internet, in this scheme, is just another wired network. You can connect your wired network to the Internet, connect your wireless network to an access point to your wired network — whatever you want.

The string of networks is potentially never-ending, with wired networks being able to break out into wireless ones as often as they need to. This concept is sometimes called lilypad networking, because it lets your computer be like a frog, hopping from lilypad to lilypad. Even though the whole area of the water isn’t covered with lilypads, the frog can still get through — and you can make wireless networks work the same way.