Choosing between antennae and beam steering

What is the difference between sectorized antennae and beam steering? Which is better in my enterprise environment, which has lots of cubicles and particle boards, as well as a significant amount of corridors?

What is the difference between sectorized antennae and beam steering? Which is better in my enterprise environment, which has lots of cubicles and particle boards, as well as a significant amount of corridors?

- Bill, Washington D.C.

There is a variety of different antennae technologies available today, each with varying levels of intelligence and functionality. To understand which is best for your environment, we’ll take a step back and provide a quick overview of the most common antennae technologies available today:

  • Sectorized antennae are the most common in wireless access points today. This refers to internal antennae that are configurable for either omni- or sectorized-directional antennae coverage. 
  • Beam-Forming – Butler Matrix is often viewed as the next step up in antennae intelligence. This type of antennae typically uses a panel of four or more antennae feeding either a digital or analog Butler Matrix to form multiple beams that can be manually or automatically steered for directional coverage.
  • Beam-Forming – Spatial Equalizer is the “ultimate” in antennae intelligence today. It typically uses a panel of four or more antennae, with a full linear transceiver behind each antenna. The spatial equalizer allows the system to produce gain in any given direction but also steers nulls in any given direction to maximize the strength of the desired signal and at the same time minimize the signal from interference sources.

While every enterprise environment is unique, nine times out of 10, I would recommend an access point with configurable sectorized antennae for traditional indoor enterprise applications. Access points with configurable sectorized antennae are the lowest in cost, simplest to deploy and provide more than adequate coverage in a business environment.

Beam-forming technologies do provide 20 to 30 dBi of antennae gain, which is an advantage over the 6 to 10 dBi provided by indoor access points with sectorized antennae. However, this advantage in antennae gain is greatly reduced when moving from an outdoor environment to an indoor environment due to the number of physical obstacles. As your specified environment has a large number of cubicles and walls, I would expect that you would see minimal extra gain from a beam forming antennae. This will probably not be enough to offset the additional cost and footprint associated with that type of solution.

Until the cost and size of beam-forming technology is significantly reduced, it is compelling only for outdoor environments and select specialized indoor applications. But since great progress is being made in this area, I would stay tuned.

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