Frequency bands / Edge and antennas / Interferences

[lmeissen]

This will sound like dumb questions... On what frequency (band)is EDGE running on?
Can you use a yagi antenna for 1800 / 1900 and connect using edge?
The signal strength reporting, is is possible to receive the wrong info?
What equipment can interfere with cell phone reception?
Can MTN or Vodacom’s towers interfere with each other?

One of my clients is using a Data card GPRS connection in there server. The signal the other day dropped 3 bars for no reason. I have done this installation a year a ago and on top of this, I bought a Duxbury EDGE PCMCIA and EDGE USB adaptors for tesing. I am testing it on different laptops, both clean. If I connect MTN datacards, it detects MTN(za) GPRS, and it is working fine. When I connect Vodacom (tried about 5 cards) it detects UMC GPRS. In the beginning it jumped between Vodacom EDGE and UMC GPRS but now only UMC. I have tested it on 2 laptops and a PC.

When it was working on Vodacom EDGE, I have done a speed test and was getting 60kb/s.

Sometimes the signal and internet speed drops. I am not sure, but it looks like it is showing the wrong signal with different operator.

Confused is not the word, and I am frustrated and really need some help or info.

 

[ajax]

This will sound like dumb questions... On what frequency (band)is EDGE running on?
Can you use a yagi antenna for 1800 / 1900 and connect using edge?
The signal strength reporting, is is possible to receive the wrong info?
What equipment can interfere with cell phone reception?
Can MTN or Vodacom’s towers interfere with each other?

One of my clients is using a Data card GPRS connection in there server. The signal the other day dropped 3 bars for no reason. I have done this installation a year a ago and on top of this, I bought a Duxbury EDGE PCMCIA and EDGE USB adaptors for tesing. I am testing it on different laptops, both clean. If I connect MTN datacards, it detects MTN(za) GPRS, and it is working fine. When I connect Vodacom (tried about 5 cards) it detects UMC GPRS. In the beginning it jumped between Vodacom EDGE and UMC GPRS but now only UMC. I have tested it on 2 laptops and a PC.

When it was working on Vodacom EDGE, I have done a speed test and was getting 60kb/s.

Sometimes the signal and internet speed drops. I am not sure, but it looks like it is showing the wrong signal with different operator.

Confused is not the word, and I am frustrated and really need some help or info.

EDGE runs on GSM900 and GSM 1800 frequencies. You can google for that. SA doesn't use the GSM 1900 band. Cell C uses the extended GSM frequency bands. You can also google for that.

You should get a Yagi for both bands. Vodacom for example uses the GSM1800 band, but they don't have carriers on those frequencies, meaning, when you connect, you connect on GSM 900 and then the network may switch you over to GSM 1800. So your antenna needs to handle both. Poynting has antennas for that.

AFAIK its not possible to get wrong info. MTN and Vodacom's towers don't interfere with each other. The networks are very well planned, although I know of a case where one network once set the wrong frequency on a tower and used a different network's band.

There are no licenced (ICASA) equipment that can interfere, at least, equipment in the hands of the public. To eliminate this possibility drive to a difference area with the laptops and retest. Perhaps there is a problem with the hardware?

 

[lmeissen]

Thank you for the info. It is definitely not hardware…

All of my problems I experience only in one town…

So if Vodacom switch you over to a different band, can you get a different signal level?

To give you more background info, and feedback…

I was testing EDGE connectivity this morning, right beside the Vodacom tower. 99% signal (29/30), reporting UMC(ua). Vodacom speed 36kb/s on speed test. Then I connect to MTN, 58% signal, 42kb/s speed test.

After this, I drove to MTN's tower. Signal Strength on MTN, 70%, Speed 48kb/s. Vodacom 61% ,42kb/s.

There is only 1 x MTN tower and 1 x Vodacom tower near the town. And the town is surrounded with mountains. The towers is 8KM from each other.

At one client, When I am pointing the Yagi antenna direct to Vodacom, I am getting better speed with MTN GPRS, and better signal. When I’m pointing it to MTN’s tower, the signal drops again and obvious the speed as swell. The MTN tower is about 2 - 3km away from this location...

I bought a I-mate jam the other day. When I load a program called "IPDashboard", the signal strength was switched arround. If standing besides vodacoms tower, it will show a signal strength of 60 - 70%. If you remove ipdashboard, the signal strength is 99%. This could be a software problem.

 

[ajax]

It is definitely not hardware…
All of my problems I experience only in one town…
So if Vodacom switch you over to a different band, can you get a different signal level?

If you get switched from GSM900 to GSM1800 and your antenna is not optimised for GSM1800 you will get a weaker signal. If the GSM1800 signal is too weak, the network may not switch you over at all. GSM1800 towers on Vodacom AFAIK are given preference but if the signal is much weaker than the GSM900 tower where you are the network will probably keep you on GSM900. This is my experience though, nothing official from Vodacom.

On the speedtests, 36kbps vs. 42kbps is hardly anything to draw conclusions from. Results will vary according to the time of day and how busy the system is down the line. It may also be that there is currently a problem in your town (where are you by the way?) and that the problem will get fixed soon.

But, since you state that there is only 1 MTN and 1 VC tower in your town, it is highly likely they are not EDGE enabled. The networks install EDGE equipment in the bigger cities/towns first or where there's a lot of data traffic. Chances are the towers are GPRS only in which case the maximum you can get is around 50-55 kbps and that is if your device can use 4 timeslots for downloading.

 

[lmeissen]

The problem is at Wolseley, but according to Vodacom’s coverage map, EDGE is enabled for Wolseley. The town is surrounded with mountains and you will have problems with most signals... Tv signal is a big no-no, you need 2 antenna's for sabc, and one for MNET... Plus you need a few boosters...

My office is in Ceres, on the other side of the mountain.

 

[ajax]

The problem is at Wolseley, but according to Vodacom’s coverage map, EDGE is enabled for Wolseley. The town is surrounded with mountains and you will have problems with most signals... Tv signal is a big no-no, you need 2 antenna's for sabc, and one for MNET... Plus you need a few boosters...

My office is in Ceres, on the other side of the mountain.

The thing that they don't tell you is the coding scheme that is available on the EDGE towers. There are different coding schemes, giving you anything from 60kbps to 230 kbps. It may be that the tower has EDGE, but it is the "slowest" of coding schemes. See
http://www.evaluationengineering.com/archive/articles/0202wireless.htm
It also depends on whether the backhaul link has been upgraded, which, according to Vodacom3g, may take a while sometimes.

As for tv, there are no tv transmitters in the Wolseley area. The nearest you can pick up, and that with a large antenna and booster would be Villiersdorp and Piketberg AFAIK.