Products

Mobile signal boosters – Installation tips to balance the signal from multiple operators

14 Oct 2017
omni vs yagi big building

When installing a DAS repeater system in a big building in a city, it is important to ensure that the signal is “balanced” from all the operators.

Firstly, take a signal measurement on the roof of the building. If you do not have a signal analyzer (image below) , instead, you can use 3 identical phones each with a different network sim in them. In our example we shall call the operators, A, B and C. (see Diagram above)

Used-Rohde-and-Schwarz-FSH18-18-ghz-Handheld-RF-Spectrum-Analyzers

It is typical for the signal of one operator to be stronger then the others. You can see in the diagram that operator C is much stronger then operator A. C is located only 50m from our building whereas A is 1000m. B is somewhere in the middle at 500m. These are big differences in distance and results in big differences in received power also.

In Diagram 1, an Omni-directional antenna receives the signal from all 3 operators and does not favor one operator over the other. The result is that unequal signal is sent to the first repeater in the system. The repeater does not differentiate between each of the operators. All it sees is the most powerful operator, in this case, operator C. If the signal level of operator C is above a the threshold level set in the repeater, the repeater will attenuate the power of operator C to a safe level. The repeater does this to ensure no overpowered signal enters the system.

The drawback to this is that, those weaker operators also get attenuated by the same amount and sometimes this means they are attenuated so much as to be useless.(See image 1, output of repeater)

You can see in diagram 1 that operator A has been wound down to zero. Operator B is wound down very low and only operator C is perfect. This is not a satisfactory result.

So how do we avoid this?

Take a look at diagram 2 above.

In this situation, we use a Yagi directional antenna instead of the omni used in diagram 1. A Yagi antenna can focus its power in one direction whilst reducing it elsewhere. By placing the Yagi strategically on the roof, in this case behind a big wall to block out the most powerful operator C and pointing it towards operator A, we can balance the 3 operators more effectively. Even though the signal being sent to the repeater is a bit overpowered, this is no problem, the repeater can attenuate it a little to reach the safe level. The main point is that the signal from each operator is roughly balanced. The repeater will then distribute this balanced signal through out the building.

 

 

You may also like:

    How to choose your StellaDoradus amplifier?

    31st July 2019
    You have done your research and decided to opt for quality legal equipment, a StellaDoradus mobile repeater. Now you have to choose the model of repeater that suits your needs. Here is a guide to help you in your choice. 1) Choosing the network band(s) The different types of networks (GSM, 3G, 4G) are transmitted [...]
    read more

    Are Mobile Phone Repeaters Legal in Ireland?

    22nd March 2019
    About a year ago, mobile phone repeaters that met certain technical requirements were made legal in Ireland. Comreg issued a list of manufacturers whose products would meet these requirements. The manufacturers are: Stella Doradus Coiler SmoothTalker Nextivity Here is a link to Comreg’s list: https://www.comreg.ie/media/2018/10/Manufacturers-List.pdf Illegal repeaters There are many companies listed on Google pretending [...]
    read more

    Best Way to Boost 4G Signal in Low Penetration Areas

    27th February 2019
    Penetration of mobile signal, especially data signal 3G and 4G can be weak in buildings with thick walls or mountainous areas. You may be sitting on your living room couch and using an internet connection from your phone, when suddenly the 3G or 4G signal drops. The construction material of a building, which can be [...]
    read more