This is continue of yesterday post.
Upgrade your base station
Routers that are based on the Draft N specification incorporate MIMO (multiple input, multiple output) antenna arrays. MIMO can improve range as well as speed. The Belkin Wireless G Plus MIMO Router released in 2007 use Draft N, and Belkin claims that the standard has twice the range of its predecessor. In the tests, range has improved a lots as other brand, such as Linksys and several other companies sell Draft N routers. Because those routers improve both transmission power and reception sensitivity, you can update just the gateway and continue using the older adapters on all your computers; the range of your network should still improve.
Add an antenna
You could also install a large, strong antenna on your base station so that it could blast out more-powerful signals. Many WiFi gateways have antennas that you can unscrew and replace with another antenna that produces a stronger signal. HyperLink Technologies has been selling antennas, and providing compatibility information about which gateways and wireless cards they work with, for years. The information is a bit technical, but it’s an exhaustive resource.
Apple has always kept its antennas inside the housing of its AirPort Base Stations; just a few of the 802.11g AirPort Extreme Base Stations came with an antenna jack for adding an external one. MacWireless has antennas, tools, and instructions for adding antennas to all AirPort models. MacWireless also offers a High Power 11g Access Point at $180. This unit has a regular-size antenna but a much more powerful radio, which provides more than 10 times the raw output power of most consumer gateways.
There is one downside to upgrading your antenna: while it can help your network, it can also mess up others. That’s because nearby networks may pick up your signals, and their performance will degrade as they try to cope with the barrage.
Upgrade your radio
If you have an older wireless network adapter without 802.11n built in, you can improve its range by attaching an 802.11n adaptor. QuickerTek nNano USB adaptor, for example, works with any Mac running Mac OS X 10.3 or later. The company also has a CardBus card and PCI Card that work with PowerPC models running Mac OS 10.3.9 or higher, and upgrade kits for Intel Macs starting at $100.
All of these adapters have one important limitation: they operate only in the crowded 2.4GHz band. But they can still improve range by transmitting farther and listening more carefully.
Add more base stations
Another way to extend network range is to build a network with many base stations, all with the same network name. WiFi adapters look for a network name, not a specific gateway. If one base station doesn’t cover your home or office, perhaps two or five or 10 might.
You could deploy a bunch of network base stations or AP, but that’d get expensive. Other 802.11g and 802.11n WiFi gateways start from around £20. In a standard network of multiple base stations, you configure one base station as the gateway, plugged into a broadband router. You connect additional base stations through Ethernet, or wirelessly through WDS (Wireless Distribution System), which is built into the base station and other gateways.
To make the multiple-base stations setup work, you need to configure the main base station as a gateway to your broadband connection.
You then configure the other base stations to pass traffic in bridge mode; that way, they leave the responsibility for assigning IP addresses to the primary base station. To set this up with the AirPort Extreme, go to AirPort Utility’s Internet pane, select the Internet Connection tab, and select Off (Bridge) from the Connection Sharing menu.
Plug the WAN (Wide Area Network) port from these subsidiary base stations into a LAN (Local Area Network) port on the primary base station, or into an Ethernet switch that’s plugged into the LAN port. For other base stations, you’ll have to check the manual.
As an alternative, you could use home power-line networking to connect base stations. Many power-line vendors offer combos consisting of a wireless access point with a built-in power-line adaptor; that way, you can extend your network without using WDS or Ethernet.