Throughout the years, countless access points and wireless routers have been held in low regard, or entirely dismissed, due to signal coverage issues. Whilst some of these may be down to poor strength transmitters, troublesome deployment environments, or too much attenuation before you get to the antennae, some of these could be easily avoided.
It’s all about deciding the right antennae for the job.
A growing number of routers and access points are now manufactured with one or two removable antenna. Different antennae have different types of connector (N-Type, SMA, etc.) but generally achieve the same goal – attaching your transmitter to the antenna.
Most access points have a “base” antenna known as an Omni-Directional (or “Omni” for short) antenna. These work best when out in the open of an office or other open area environment. Their effective transmission area (or “beam spread”) is best simplified as a donut. If we were to look at the wave from above, this would radiate outwards at all angles. Looking from the side; the signal spread would be going out to the sides, with only a small deviation in height.
Once you understand how the theory behind beam spread works, you start to appreciate where manipulating that beam spread can greatly improve your wireless network. Which leads us onto directional antennae.
Directional antennae are just that – a method of taking that 360-degree beam spread of an omni and focus it down a defined path/direction. There are various types that you can adopt for your particular situation: Sector, Flat Panel, Grid, or even Dish. The coverage areas are conical, and depending on the specific manufacturer, vary from being a wide coverage area (Sector antennae can be compared in beam spread appearance to a traditional Japanese fan) to being a very narrow and focused beam spread pattern (the most-narrow usually being that of Grid or Dish antennae).
Practical application of these could be for example in a warehouse environment; wanting to have a Sector antenna transmitting down the length of a warehouse walkway for wireless stock systems (Symbol hand-scanners, wireless VoIP phones, etc.). Such an environment would suffer with Omni’s being used everywhere. However, a practical combination of omni (for open areas) and Sector (for directed beams down walkways between heavily stocked racking) could make for a well-covered environment with little (or no) signal dead spots.
Dish antennae are similarly suited for such things as building-to-building networking where physical cabling is prohibitively priced.
Take some time to review your antennae options before undertaking a task, it could save you all sorts of trouble in the long term!