Good enough signal strength question?

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SAdata

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I used to be covered by the coverage map of my 3G provider, but recently I see that I have become "uncovered" :sick: by the same map :( however my connection still works fine. I am currently on prepaid, but I am very keen to get a contract as it is much better value, but I don't want the signal to disappear halfway through it due to increased users on the tower and have no recourse because I am not covered.

I currently pick up signal (per MDMA) anywhere from -85dbm to -95dbm, but it usually hovers between -89dbm and -93dbm.

I don't suffer any disconnects and the speed is fine - 1 to 4 mbps depending on the time of day..

What is the likelihood of the signal actually disappearing and should I get the contract considering all of the above? :) thanks :)
 
mmmmm never heard of anyone becomming "uncovered" on the map before. Possible scenario I guess would be that the owner of the property where the BTS that provides you with coverage is located not willing to extend the lease agreement...meaning that the tower will need to be switched off and removed. This I think is very unlikely...but a possibility. I vaguely remember something like this happening in Bryanston a few years ago.

Maybe put your enquiry to your network provider and see if they can advise you. Could just be a mistake that was made with the last editing of the map?
 
Ockie said:
mmmmm never heard of anyone becomming "uncovered" on the map before. Possible scenario I guess would be that the owner of the property where the BTS that provides you with coverage is located not willing to extend the lease agreement...meaning that the tower will need to be switched off and removed. This I think is very unlikely...but a possibility. I vaguely remember something like this happening in Bryanston a few years ago.

Maybe put your enquiry to your network provider and see if they can advise you. Could just be a mistake that was made with the last editing of the map?
Click to expand...

I asked them they said it was possible that the antenna had been tilted a bit (I was on the fringe of coverage by about 200m). Yes I saw that they had updated their map as there were new areas covered, the signal for my area has just moved off a bit but it looks like the original cell is still there (I know where the antenna is located).
 
Hi There,
Maybe ask them what plans they have to install another antenna or modify the existing one to guarantee you coverage. Have you looked at the other service providers to see if they offer better coverage?

Regards

TIm
 
They said they miiighhht be putting one in by the end of the year. We shall have to see. Well I like this network and despite the low signal it provides the best service & value in my area.

Is -85dbm to -95dbm that bad? :p
 
I connect to MTN at about- 87to-95dBm to a MTN/Vodacom tower about 400m from my home, it’s ironic but I can connect via 8ta/Telkom to the same tower with a signal of- 67to-73dBM. After playing with MDMA I found that 8ta is connecting on 900UMTS and MTN on 2100UMTS. 900 just travels much better than 2100 but my connection is also stable and speed reasonable at -95dBM.
 
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Had only Edge on MTN till yesterday. I got hold of their coverage department two weeks back. They installed a high gain antenna yesterday free of charge. I now get 5mbit downstream
 
At -85--95dBm you are at cell-edge. Your speed can be still good (assuming sufficient signal-noise margin), but It means that your connection depends heavily on other users usage, as tower gives preference to the users with the best signal. It is called cell breathing, under heavy tower load you can be even prevented from registering to the network.
 
sajunky said:
At -85--95dBm you are at cell-edge. Your speed can be still good (assuming sufficient signal-noise margin), but It means that your connection depends heavily on other users usage, as tower gives preference to the users with the best signal. It is called cell breathing, under heavy tower load you can be even prevented from registering to the network.
Click to expand...

Yes the speed is quite variable its usually perfect but occasionally it can get very slow. If you had good signal would you not suffer cell breathing at all? Like would it be quick even if the tower was under load? :) please explain SNR to me? :) I see it on MDMA I tried to find out what it was about but I didn't get anywhere
 
SAdata said:
If you had good signal would you not suffer cell breathing at all? Like would it be quick even if the tower was under load? :)
Click to expand...
1. Yes, 2. No.
Cell breathing is preferencial treatment for allocating codes (your maximum speed). In extreme conditions cell coverage area is shrinking (no registration to the network allowed). All users with good quality signal share more equal threatment (there might be preference to users having faster device though, I don't know). In other words there are not subject to cell breathing, but of course they share bandwith with other users. It is linear degradation of speed. Cell breathing is progressive degradation.

SAdata said:
please explain SNR to me? :) I see it on MDMA I tried to find out what it was about but I didn't get anywhere
Click to expand...
Problem is that pair of numbers reported by modem (and displayed in MDMA on some newer modems starting from E1820) is not documented. There are speculations that it represent RSCP and Ec\Io, so search for these, you might be more lucky. :)
From my observation these numbers become less negative (closer to 0) when signal quality increases. The first parameter value is fluctuating around RSSI, I noticed increase of speed when this value is higher than RSSI, so when positioning antenna, it is important to tune on this parameter, not RSSI.
 
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sajunky said:
1. Yes, 2. No.
Cell breathing is preferencial treatment for allocating codes (your maximum speed). In extreme conditions cell coverage area is shrinking (no registration to the network allowed). All users with good quality signal share more equal threatment (there might be preference to users having faster device though, I don't know). In other words there are not subject to cell breathing, but of course they share bandwith with other users. It is linear degradation of speed. Cell breathing is progressive degradation.
Click to expand...


Sorry, your understanding of cell breathing is not really correct.

From http://www.telecomabc.com/c/cell-breathing.html


Cell breathing
(Respiration)

Cell breathing (or respiration) is a term used to reflect the fact that the coverage area of a base station in a CDMA system will become smaller if there are more subscribers.

While in conventional FDMA and TDMA systems, like GSM, each subscriber has the full transmission power of the base station, in CDMA systems (like UMTS and CDMA2000), the output power of the base station is divided among all active subscribers.

If, for example, a total power of 20 watts is available, the network can feed 10 watts to each of two subscribers, or, 2 watts to each of 10 subscribers. The maximum output power available for an individual subscriber depends on the number of active subscribers in each radio cell. The more subscribers logged on to the cell, the lower the power available for a individual subscriber and hence the lower its range.
Click to expand...


So basically what has happened to the OP is that MTN down tilted the site for some reason, usually to better the overall network quality. Now there is more chance of experiencing the effect of cell breathing as he is completely at cell edge.
 
SteveO said:
Sorry, your understanding of cell breathing is not really correct.

From http://www.telecomabc.com/c/cell-breathing.html
Click to expand...
Above link is complete rubbish. Definition of cell breathing has nothing to do with transmit power. Look at Wikipedia if doubts. Cell breathing is a mechanism to provide load balancing.
In more technical terms distant users will get allocated less codes (actual bandwith) and in extreme condition will be forced to handover to neighbouring cells. New distant users will be refused registration to the overloaded cell.
 
rakabos3 said:
This is what MTN installed at my place and it made a massive difference

http://www.poyntingdirect.co.za/pLP...cellphones-and-routers-include-7-m-cable.aspx
Click to expand...

I unfortunately can't get an external anetnna - my device doesn't have an antenna plug. And not going to shell out a few R1000's on 3g right now. I'd rather spend it on an LTE modem when stuff starts happening there.

Sajunky, would you experience a decrease in RSSI when cell breathing happens? Or just a decrease in performance. I checked my SNR now it was like 96, 8 but I've seen it go to 140, 32 or something like that?
 
SAdata said:
I unfortunately can't get an external anetnna - my device doesn't have an antenna plug. And not going to shell out a few R1000's on 3g right now. I'd rather spend it on an LTE modem when stuff starts happening there.

Sajunky, would you experience a decrease in RSSI when cell breathing happens? Or just a decrease in performance. I checked my SNR now it was like 96, 8 but I've seen it go to 140, 32 or something like that?
Click to expand...

Your modem doesnt need a jack to work with an antenna. Granted the E367 modem i use has a jack i dont use it. The installation came with a rubber sleeve that slides over the dongle which then runs via SMA cable to the antenna, sorted
 
SAdata said:
Sajunky, would you experience a decrease in RSSI when cell breathing happens? Or just a decrease in performance. I checked my SNR now it was like 96, 8 but I've seen it go to 140, 32 or something like that?
Click to expand...
No, decrease RSSI with the same Cell_ID won't happen, but if you are experiencing forced handover, modem will pickup some other cell, even RSSI from a new cell is lower.

See bold part quoted: If RSSI is the same, this is indication of poor signal quality, presence of strong interferences.

I suggest external antenna. Even the cheap window monted, it brings you to the area of better signal.

The cheapest quality HSPA+ modem with external antenna connector is E352 R349 from MTN stores. EDIT: I see other post suggesting inductive coupler. It is possible, bu it will lose 6dB on the coupler, with your RSSI levels not recommended.
 
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sajunky said:
No, decrease RSSI with the same Cell_ID won't happen, but if you are experiencing forced handover, modem will pickup some other cell, even RSSI from a new cell is lower.

See bold part quoted: If RSSI is the same, this is indication of poor signal quality, presence of strong interferences.

I suggest external antenna. Even the cheap window monted, it brings you to the area of better signal.

The cheapest quality HSPA+ modem with external antenna connector is E352 R349 from MTN stores. EDIT: I see other post suggesting inductive coupler. It is possible, bu it will lose 6dB on the coupler, with your RSSI levels not recommended.
Click to expand...

Hmmmm okay. I'm so angry I bought the stupid e173 its the same price as the e352. At the time I didn't realise you could use modems across networks (rookie error). I might look into that then... -throws the e173 in the toilet:p

For the SNR the first bit is your rssi. I'm taking a guess, maybe the second one is the number of users connected to the tower :p hence why its low its fast, when its high its slow
 
SAdata said:
I'm taking a guess, maybe the second one is the number of users connected to the tower :p hence why its low its fast, when its high its slow
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:D

Thanks for feedback, I didn't know if E173 supports SNR (and do it correctly).
 
sajunky said:
:D

Thanks for feedback, I didn't know if E173 supports SNR (and do it correctly).
Click to expand...

Hahaha does that mean I hit the nail on the head? ;) that's so hectic! Were u involved in the development of MDMA?? Seen you're name on a few of the threads.

It does seem to pick it up, but it only reflects it at opening of the program - I.e. Doesn't update, so u have to open, close, open close to see if it updates
 
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