4. Extend Coverage Using HomePlug Powerline ($40+ for Router-to-Outlet Adapter and $70+ for AP/Adapter)
If you really need to boost your signal, you can extend your coverage easily by using your building's electrical wiring. Like the method discussed in the next section, "Adding Access Points," you would be adding another wireless AP to your network.
However, instead of running Ethernet cables, you would use powerline adapters to transmit data through the electrical lines.
To power your lines with network connectivity, you would just plug in an adapter at an electrical outlet near the router and hook a cable between them. Then from any other plugs in the home or office, you would plug in an adapter or adapter/AP combo.
If you use an adapter, you could run an Ethernet cable directly to a computer or to an AP. If you use the combo device, you would instantly have additional wireless connectivity.
If you have an extra router or AP around (such as from upgrading to Wireless N), you'll probably want to go with the plain adapter to save money.
This is an alternative to using wireless extenders or repeaters, discussed tremendously elsewhere. Though extending coverage using powerline networking can be a bit more expensive, it doesn't have the negative performance affects.
If you find you need to extend even farther, you'll probably save money by going this route; it's only around $40 to buy a new powerline adapter.