Everything You Didn’t Know About Two Way Radio Line of Sight
If you’ve had issues with your two way radio signal in the past, you may have had someone ask you whether or not you have line of sight. Effective radio transmission requires a clear path between the receiving and transmitting antennas. That free path is the line of sight.
There are, however, other factors to consider – the biggest one being the Fresnel effect. A radio signal path does not fall in a direct straight line, but there is an “elliptical” area around the beam that surrounds the free path to the tower. This area, called the Fresnel zone, varies in thickness depending on the length of the path between towers and the frequency of the signal being used.
Once you have a full grasp of the Fresnel effect, the concept of line of sight is actually quite simple. The three types of line of sight are:
- Clear Line of Sight – This is when you achieve optimal signal abilities with your two way radio. In this case, there are no visual obstructions, and the Fresnel effect is not impacted at all, allowing clear receiving and transmitting.
- Near Line of Sight – Some obstructions of signaling which doesn’t greatly impact signal, but can result in errors or trouble with the throughput of messaging etc. The Fresnel zone would be slightly obstructed by say a tree, or the top of a hill.
- Non-Line of Sight – In this case, obstructions such as hills and other buildings etc. prevent the best use of signal abilities and the Fresnel zone is impacted. This doesn’t necessarily mean that signals cannot work, but rather they do not work all the time – depending on the situation (storms, cloud cover etc.)
So how can you improve your line of sight? There are a few steps that are often considered:
- Raise the antenna mount point for better reach of signal
- Increase the height of existing towers
- Locate another mounting point (a different building or tower)
- Remove obstructions by trimming trees
But, if you’re working with the Nova Communications team, let our experts figure out what the best options are, and do that work for you! Through our quality service we can provide engineering insight and the right tools to meet your needs.
Want to learn more? Check out our Professional Services Brochure to see how our team can help you below, or contact us today.