Wireless networking

Wireless networking

Tuesday 18 June 2013

Wireless networking

 

Wireless networking is exactly what its name implies - networking that doesn't use wires but instead uses radio waves.  Just like wired networks, most wireless networks have devices that speak to each other through a central device called an access point.  In a home or small business an access point is usually built into a router, making it a wireless router.  On the PC side you also need a wireless connection (referred to as a wireless NIC).  Most newer laptops come with an integrated wireless NIC, but older laptop and non-laptop PCs might need to have an adapter added, usually a USB device or a PCMCIA card.
Just because it's called wireless networking doesn't mean they are exclusively wireless.  Usually a wireless router has wired network connections and an antenna for wireless networking, and both the wired and wireless networking occur simultaneously.
One confusing area of wireless networking is the compatibility of the many standards that exist.  Wireless networking is governed by the 802.11 set of computer standards, each standard being given a different letter suffix, so you have the 802.11a standard, the 802.11b standard, and so on.  When you purchase a wireless router or NIC they will be labeled with which standard they support.  Many times the standard will only be referred to with the suffix letter, so you'll see something labeled as "wireless G" meaning the 802.11g standard.
There are four standards that you need to worry about when purchasing wireless routers or NICs: a, b, g & n.  Here are two charts showing what is compatible with what:
 

This wireless router ...	... will work with these wireless NICs
802.11a wireless router	802.11a wireless NIC 802.11n wireless NIC
802.11b wireless router	802.11b wireless NIC 802.11g wireless NIC 802.11n wireless NIC
802.11g wireless router	802.11b wireless NIC 802.11g wireless NIC 802.11n wireless NIC
802.11n wireless router	802.11a wireless NIC 802.11b wireless NIC 802.11g wireless NIC 802.11n wireless NIC

 

This wireless NIC ...	... will work with these wireless routers
802.11a wireless NIC	802.11a wireless router 802.11n wireless router
802.11b wireless NIC	802.11b wireless router 802.11g wireless router 802.11n wireless router
802.11g wireless NIC	802.11b wireless router 802.11g wireless router 802.11n wireless router
802.11n wireless NIC	802.11a wireless router 802.11b wireless router 802.11g wireless router 802.11n wireless router

One important note about the above chart is that the when you mix devices from different standards you'll usually get the performance of the slower standard.  So, for example, 802.11b devices have a maximum speed of 11 Mbps, and 802.11g devices have a maximum speed of 54 Mbps.  If you have a wireless router that is 802.11b and a wireless NIC that is 802.11g (or vice versa) you'll only get 802.11b speeds, or a maximum of 11Mbps.
If you'd like our assistance setting up a wireless network,

Wireless security

The appeal of wireless networking is in its convenience - you can have your laptop anywhere within range of your wireless router and still access the internet.  The problem with wireless networking lies it this same fact.  More than likely you can connect to your wireless router by sitting in your car parked in front of your house, and if you can do that with your laptop somebody else can do the same thing with their laptop.  And, by accessing your wireless router they are inside your router's firewall and therefore can potentially get to any shared files you have on other computers inside your firewall.  If you're going to have a wireless network you need to implement some wireless security by using some form of encryption.
There are four levels of wireless encryption for homes and small businesses:

	Unsecured
	WEP: Wired Equivalent Privacy
	WPA: Wi-Fi Protected Access
	WPA2: Wi-Fi Protected Access 2

Here's what each means:
Unsecured:  No encryption is enabled.  Anybody can connect to your network as long as they are within range of your wireless router.
WEP:  WEP was the original wireless encryption industry standard.  Unfortunately, is was based on a simple algorithm and can be cracked easily by anybody who wants to spend a few hours learning how.  While WEP is better than an unsecured network, it's not better by much.
WPA:  After WEP was cracked, there was a move to create another industry standard that was more robust.  Industry standards, however, take a while to get ratified and there was an immediate need.  WPA is an unofficial, de facto standard for wireless encryption and is significantly better than WEP.
WPA2:  The official industry standard for wireless encryption, it is stronger than WPA.
Most newer wireless hardware will support all four options.  Some older hardware will only support WEP or WPA.
One more note: WPA2 uses a more intense encryption algorithm than WEP or WPA, so some older wireless hardware slows down if you use WPA2.
There's more to wireless security than what's been covered here, but encryption is the first step for securing any wireless network.  Don't leave your wireless network unsecured, and don't kid yourself by securing your network with WEP, use WPA or WPA2.