GSM repeaters

[woth5]

Hi!

My question would be about GSM repeaters.

When you install GSM band selective repeaters, what about zones that are covered both by repeater and donor BTS site? For example, when you have in-building solution with GSM repeater, some of the "repeated" signal will go out of building and mix with existing signal on same channel. This is impossible to avoid, because you cannot set boundaries to signal.

So my question is: is 12dB margin enough to avoid potential problems? does receiver see both signal but consider it as multipath fading? is there any problems that I'm not aware of?

[LoBzA4]

Hi!

My question would be about GSM repeaters.

When you install GSM band selective repeaters, what about zones that are covered both by repeater and donor BTS site? For example, when you have in-building solution with GSM repeater, some of the "repeated" signal will go out of building and mix with existing signal on same channel. This is impossible to avoid, because you cannot set boundaries to signal.

So my question is: is 12dB margin enough to avoid potential problems? does receiver see both signal but consider it as multipath fading? is there any problems that I'm not aware of?

For incoming signal at repeater usualy using antenna with very narrow diagram, allmost like MW:) and antenna installing somewere on the top of bilding. For indor solutions usualy using small antennas with small gain and uotdoor signal from this antenna will be mutch less then usual outdoor signal from BTS. So I think you will not have any problem!

[woth5]

Actually I do have a problem.

I used test transmitter to see how signal propagate inside and outside the building. If I use small signal strenth then I can't cover whole building. If I use enough strenth to cover the building, then I have some signal going outdoor and mixing with the Donor BTS signal.

So I have a situation where on the same spot on parking just outside of building I have a -85dBm from repeater, and a -85dBm from donor BTS.

I know that one of the solution would be to use multiple antennas inside with lower EIRP per antenna, but is hard to implement due to other reasons(not RF related). So I have to use just 1 antenna in-building.

My question would be: will the mobile station outside the building (on the parking) be camping on repeater signal, or on the BTS signal (they are the same level). There is possibility that the signal from the repeater will be discarted at the BTS due to delay at the repeater. If not, then how much difference in dB there should be so the system would work correctly. Usual 12dB should be enough?

[LoBzA4]

Actually I do have a problem.

I used test transmitter to see how signal propagate inside and outside the building. If I use small signal strenth then I can't cover whole building. If I use enough strenth to cover the building, then I have some signal going outdoor and mixing with the Donor BTS signal.

So I have a situation where on the same spot on parking just outside of building I have a -85dBm from repeater, and a -85dBm from donor BTS.

I know that one of the solution would be to use multiple antennas inside with lower EIRP per antenna, but is hard to implement due to other reasons(not RF related). So I have to use just 1 antenna in-building.

My question would be: will the mobile station outside the building (on the parking) be camping on repeater signal, or on the BTS signal (they are the same level). There is possibility that the signal from the repeater will be discarted at the BTS due to delay at the repeater. If not, then how much difference in dB there should be so the system would work correctly. Usual 12dB should be enough?

As I now radio propogational model, all should work correctly(but not sure=)). If you will put 12 dB margin, thesame situation will be in some another place(not in parking). If you have somewere testphone, better to try without some changes test that place in dedicated mode and you will see everything;)

[woth5]

As I now radio propogational model, all should work correctly(but not sure=)). If you will put 12 dB margin, thesame situation will be in some another place(not in parking). If you have somewere testphone, better to try without some changes test that place in dedicated mode and you will see everything;)

I don't have test equipment for dedicated mode, just idle mode (pure signal strenth in dBm and nothing else), hence the dilemma.

[LoBzA4]

I don't have test equipment for dedicated mode, just idle mode (pure signal strenth in dBm and nothing else), hence the dilemma.

you can call from your's mobile to someone enytime) and test that area in real speek))

[woth5]

you can call from your's mobile to someone enytime) and test that area in real speek))

But the repeater is not yet installed. The call should be ok right know. I'm wondering what will happen once the repeater is installed, and how to prevent collision between signals from BTS and from repeater.