The rise of mobile electronic devices, which need internet access has changed the demand we have on our home networks. The days are over where one had a single computer connected with a wire to the broad-band internet modem. WLANs became very popular because network client became more mobile. It started with the notebooks with which you could browse the net on your couch completely wirelessly and it became even more popular with the rise of the iPhones and iPads which should use the home internet access when used around the house. The question to solve is:
How can one achieve a good WLAN coverage so that one can use his internet-depending devices anywhere at home?
The Simplest Solution — A Single Access Point
The simplest solution would be to have only a single access point often combined with a router attached to the broad-band internet access of the house. This solution is easy to deploy and maintain, however it could be that the coverage over the entire house and different floors is not complete.
Using a LAN as a Backbone for Different Floors
Another approach is possible if there is a wired LAN in the house which for example connects the floors and is connected to the internet access. To this wired LAN all the access points are attached and if their network name (the SSID) and the encryption type and password are the same, network device can do a handover between two access points. The advantage is that each wireless access point is transmitting at full speed, because data is send over the air only once.
There are several possibilities to simplify the deployment of the access points and make the whole setup more manageable. The pro solution would be to use a WLAN switch, which looks like a usual ethernet switch but is able to manage attached access points. With such a switch it is possible to enter the configuration data only once and sent it out to all the compatible access points in the network. Other more sophisticated things like load balancing and automatic transmission power regulation are possible. The drawback like with every enterprise-class product is price. To build such a network, a central WLAN switch with compatible access points have to be bought, which can get expensive.
There is however a different approach by Ubiquiti Networks with their UniFi access points. These are APs which have logic in each AP but can be managed like a WLAN switch setup. You just do not have to buy one. This much cheaper and could be of interest of larger homes.
However what if it is not possible to deploy a wired LAN at home? There is also a solution for that:
Wireless-only Network Setup
Without a cable LAN one has to rely on power line, meaning LAN over power cables or use multiple APs to extend the wireless coverage. A neat way of doing this is using a wireless distribution system (WDS). A WDS is working like bridge at link level, meaning that it is fully transparent for the upper network protocols like TCP/IP or UDP. Deploying a WDS is easy and is basically the same as using a wired backbone, except there is none. The problem arises if encryption is turned on. In general only unencrypted and WEP-encrypted mode can be used in a WDS. This is usually not an option. However there are vendors that support using WPA2 mode in their WDS, but you usually cannot mix devices from different vendors. I am using a WDS consisting of an Airport Extreme and an Airport Express and it is working flawlessly in WPA2 mode. The bandwidth of the wireless connection however is halved as data has to be received and has to be resend to the client which means it is send over the air twice.
Tipps for Placing the Access Points
- Locate areas with weak signal strength and add an additional AP there if there is a cable backbone. If there is none and a WDS is used place the AP such that it has still a good wireless connection to the home base.
- Use a network tool like KisMac to determine which channels are occupied by other WLAN APs in the area. Sample the whole area where the network should be to cover interferences from different neighbors. Use a free or less occupied channel in the frequency band. This is especially important for WDS as a fixed channel has to be chosen.
- Use KisMac to measure the signal strength to improve the placing of the APs and the direction of the antenna. This is best done with two people: one at the antenna and one at the notebook.
Deploying a WLAN in your home can be tricky if no proper tools are used. Using a network scanner such as KisMac and some time to experiment with the positioning can pay off very well.
Nice review Thomas!