-Access Points (APs) are sometimes referred to as wireless base stations, WAPs, even (albeit incorrectly) as hubs or routers. You may also see terms like residential gateway or Internet gateway device mentioned. Despite the number of synonyms, as far as the wireless network is concerned, they all mean basically the same thing. Some may have more features than others, which often explains their incorrect names – eg, a WAP can have a hub or router built in.

First of all, though, if the ad hoc system works, why do you need to go to the expense of buying this extra equipment? Can’t you do a lot with the simpler ad hoc network?

Yes you can, but. . .

As we briefly mentioned last month, it is possible (for example) to connect to the internet from an ad hoc network. It is also possible to set up a wireless access point using software on perhaps an old PC – that is, without buying extra hardware. But the truth is that it is not very often done – most wireless networks use the infrastructure mode with an AP. Why?

(a) it offers more features and more security than the ad hoc mode;

(b) it is usually much simpler to go the hardware route, especially if you want to do more than swap files; and

(c) if you only have a dial-up conenction, there are good reasons, associated with the way IP addresses are handed out, not to use a software AP.

Two different types of Access Points, showing both front and rear so you can see the difference. At left is a Wireless Router/AP ($179 from Jaycar Electronics) which combines the functions of an AP for wireless networks and a router for wired networks. At right is a basic Access Point ($99 from Freenet Antennas).

You would normally also expect better range from an AP, if for no other reason than the AP can be mounted in a much more beneficial location. In an ad hoc system, communication is direct from the wireless network card in each computer to its counterpart in another computer.

But unless there is a (often lossy!) antenna extension cable, the antenna is normally located hard up against the back plane of the computer – it normally directly screws into the internal wireless network interface card, or NIC. And the computer is often at floor level or hard up against a wall – hardly the best radio environment. In any event, the bulk of the computer case often provides a very effective radio shield over about 180°!

The AP too usually has integrated antenna(s) but it can be mounted well clear of obstacles, filing cabinets, people . . . we’ll get back to this shortly.

Naturally, all computers on the wireless network will still have to have a wireless NIC to be able to talk to the AP (many modern laptops have them built in). But it helps to have the AP mounted in as good a position as possible to give each of those computers a fighting chance!