Choosing the Right Equipment

This section is useful:
•   To compare how various wireless devices should be used, or
•   If Choosing the Best Locations and Tuning Your Equipment don't get the performance you want, or
•   You want a big improvement immediately at a reasonable cost.

The cheaper solutions are first, followed by more expensive, but very powerful ones. A network with more than a few computers may benefit from a combination of approaches.

     I. A New Router 
     II. A Second Router as a Wireless Access Point 
     III. Powerline 
     IV. An Access Point 
     V. An Antenna 
     VI. Bi-directional Amplifier
     VII. A Site Survey

I. A New Router

Replace your existing router with a better one. This is recommended if your router is a couple years old. A new router will probably double your coverage in a single area.

Advantages
•   Making the change is likely to be simple.

Disadvantages
•   May require you to also buy new adapters to get all the router benefits.
•   Isn't best for difficult environments with spotty coverage, or for covering large areas such as entire buildings.

II. A Second Router to use as a Wireless Access Point

With this solution you disable features of a wireless router, leaving the wireless transmitter working. This configuration uses an existing wired or wireless router.

Advantages
•   Low cost. With an inexpensive router, this is the cheapest solution.

Disadvantages
•   Only suitable for small, moderately loaded networks. E.g., not good for running a game server or a database server.
•   Can be slightly difficult to configure.

III. Powerline

Instead of networking through the air, or through Ethernet cables, Powerline uses the existing electrical wires in your walls.

Advantages
•   Fairly low cost.
•   Excellent solution in difficult RFI environments, since Powerline signals don't go through the air.
•   Good security for casual users.
•   Powerline can easily be moved in a house. No reconfiguration is needed, units can be plugged in where and when you want.
•   Doesn't require continuous wireless coverage, just an available electrical plug.
•   Works nicely with wireless technology to cover "blind spots".

Disadvantages
•   Powerline performance is not limited by RFI, but it is limited by noisy power. As with wireless, it's difficult to know exactly how well Powerline will work until you try it.
•   Powerline is often not suitable for businesses, dorms, and hotels.

IV. An Access Point

Dedicated access points have better performance and features than routers that are used as access points.

Advantages
•   Can cover an area far distant from your wireless router, without having to cover all the area in between.
•   Potentially excellent LAN performance, especially with careful configuration and placement.
•   Advanced security features.

Disadvantages
•   Business access
•   Using access points in repeater mode does not result in the best performance.
•   Configuration is more complicated than other solutions.

V. Antennas

Antennas can provide great power.  Antennas and boosters are available that transmit for tens of kilometers. Less powerful antennas may still cover an entire building.

Advantages
•   Antennas give excellent throughput over large continuous areas.
•   Antennas are available for outdoor, as well as indoor use.
•   Antennas are often the most practical solution for networking between buildings.

Disadvantages
•   Antennas must be connected to equipment specifically designed for them. This adds to cost.
•   A site survey may be needed before installation. (See below.)
•   Antennas may require professional installation. This adds to cost.
•   In thunderstorms, connections may be slow or temporarily interrupted. Critical networking or networking in areas of frequent storms may require other network connections as a backup.
  

VI. Bi-directional Amplifiers

Amplifiers give about 10 dB to 20 dB extra transmit power for the Wireless LAN network significantly increasing the range of the network by three to fifteen times.
Bi-directional amplifiers consist:
•   Transmit path provides highly linear gain of 17 to 23 dB.
•   Low Noise Amplifier with signal gain of 12 dB to 20 dB improves the receive sensitivity of radio, while keeping noise level very low.
•   Receive Filtering. A band pass filter in receive path of the amplifier gives added protection against out of band noise. 

Advantages
 •  Increased network throughput and far reliable connection.

Disadvantages
 •   Possibility of interference with adjacent wireless LAN networks.


VII. A Site Survey

A site survey is a study of your environment, your network, and your computing needs. Self-help site survey software is available, but a complete evaluation requires a professional. For a network of more than a few computers, plan on using 1-2 hours of help in the range of €100-€150 / hour. For all but small networks using the cheaper approaches described above, the amount spent will be saved by avoiding buying wrong equipment, or equipment that isn't cost-effective in your situation.