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Being a newbie and only having an XDA1 I keep hearing the words GPRS and GSM banded about. Can someone plse tell me the differences between the two>???
Thanks john
GPRS is short for General Packet Radio Service, a standard for wireless communications which runs at speeds up to 115 kilobits per second,
GSM (Global System for Mobile Communications) 9.6 kilobits. so 11 times slower
GSM is mostly used for voice calls and SMS
GPRS for DATA-transfer ie MMS,surfing,email,...
GSM is usually charged by time ie minutes/second
GPRS by amount of data ie KiloBytes,Megabytes
You can surf or check email with GSM but then you'll have to use your GSM as a modem with a dial-in connection.
That's what i think, maybe I'm wrong but I'm sure the experts will correct me.
M4io said:
GPRS is short for General Packet Radio Service, a standard for wireless communications which runs at speeds up to 115 kilobits per second,
GSM (Global System for Mobile Communications) 9.6 kilobits. so 11 times slower
GSM is mostly used for voice calls and SMS
GPRS for DATA-transfer ie MMS,surfing,email,...
GSM is usually charged by time ie minutes/second
GPRS by amount of data ie KiloBytes,Megabytes
You can surf or check email with GSM but then you'll have to use your GSM as a modem with a dial-in connection.
That's what i think, maybe I'm wrong but I'm sure the experts will correct me.
Click to expand...
Click to collapse
You are right.
GPRS is a data transfer protocol which runs OVER the GSM network. GPRS is a digital based protocol which is why high speeds can be achieved compared to GSM.
GPRS & GSM
Yep. generally speaking.........
Both can be used to surf the net (WWW) but generally GPRS is cheaper and faster.
GSM will dial up a server for your email and surfing. Your calls over GSM to a server generally cost 10 pence per minute, although it can be free depending on your personal tariff with your network (O2, Orange, Vodaphone, T Mobile, 3....)
GPRS is connected by your service provider, and you pay for what you download, by the KB, prices range fron £1 a megabyte to £7 depending on the supplier.
Coverage varies from mobile to mobile and area to area and of course network to network, for both GPRS & GSM.
Hi
For the networks, supporting GPRS meant a relatively simple firmware update to all but the oldest base stations. GPRS is pretty crude, if offers higher data rates at the expense of network capacity and makes poor use of the available spectrum (compared to W-CDMA G3 modulation schemes).
A basestation will have available to it a number of standard frequencies for GSM comms, say 50 channels, these channels will be different to the channels used on the neighboring base stations.
Each of these channels is split up into 8 time slots. In a GSM config, a mobile gets 1 timeslot, so 8 calls can take place 'at the same time' on the same channel. The base station and mobiles decide who is gonna transmit and when. This happens so fast that as far as the user is concerned they have a comms channel to themselves. This is TDMA Time Domain, Multiple Access.
Interestingly the time slots are so narrow that if you have phone A on located 20KM from the base station on timeslot 8, and phone B next to the base station on timeslot 2, then phone A will transmit its data before phone B, with the data arriving at the base station in correct time-slot order!
Mobile networks also support time-slot and channel hopping to get around network interference problems, and more importantly to counteract the issues of dopler shift when the mobile is moving at speed.
GPRS works simply by making more of these timeslots available to a single mobile. The fact that data is bursty means that the base station can hand out timeslots fairly efficiently. The 2 current systems for GPRS are class 8 and class 10
Class 8 offers 4 download timeslots and 1 upload timeslot
Class 10 offers 3 download timeslot and 2 upload timeslots
Each slot offers from 9.6K to 21.4K depending on network configuration (basically thats the width the RF channel, perhaps also the no of slots that the channel is split into - cant remember). In the UK I beleieve that each timeslot runs at 14.4K. You will however not see that since some of it is used for error correction.
O2 defaults to class 10. I dont know whether this is locked at the network level and I never tried changing it.
Class 10 will hence give max 43.2K down / 28800 up and
class 8 is 57.6K down, 14.4K up
You can knock 20% of those figures for error correction duties.
It would be possible for GPRS to run in 7/1 mode to give 7x14K4 = 100.8K down / 14.4K up. I dont think any networks or devices support such a configuration though!
Its been a while since I worked in this field so this info may be out of date by now. GPRS is not that much faster than HSCSD (high speed circuit switched data), but its much more efficient in its use of the bandwidth.
Ever been up a mountain miles from nowhere, had a screen full of signal bars but never managed to make a call?? Its a limitation of GSM (or rather the config of the network). A phone must be able to respond within the correct timeslot, if the phone is too far away then it can miss its slot altogether, hence full bars, but no calling! In the UK, the network setup means that the limit is around 25KM, in australia, they have extended this to around 100KM in rural locations.
Roll on EDGE - 2.5G++ its a new modulation scheme for GSM that makes *much much* better use of the spectrum. Should give us 256K on the move - i.e it will be pushing into 3G terratory bandwidth wise. Trouble is, GPRS was a firmware update for most base stations, EDGE is gonna require hardware. I would not be surprised though if we did not see networks giving up on taking 3G coverage beyond 70-80% of population, and rely on EDGE/GPRS to cover the dregs.
Nigel
Is there a way I can still get my GSM calls when I am connected to GPRS ?
As a matter of fact I do when the GPRS is Idle. But when there is some data transfer happening and a call comes in, It goes off to my voice mail !!!
Isn't it supposed to put the GPRS on hold and take the call ?
Any settings or any ideas ?
regards,
Arun
It seems to me that Universal phone sensivity is to bad.
It is frequent at less good GSM coverage areas, I'm to be the first one who can't make calls with my Universal phone. Even considering only the subscribers of the same operator as mine.
Usally also get the lowest signal strength indication.
Do you have similar feelings?
Is there anyway to improve this?
If feel it is not a SW or Radio.nbf version problem. It should be related with some HW weakness?
You could set the radio preference to GSM only - some users have reported improved performance compared to the setting for GSM + UMTS.
Hello,
I know the place in the phone options (on the band page) where you can
change the network from GPRS to UMTS (3G).
But is this possible to do programmatically with RIL or TAPI or another API
on the pocket pc device?
Thanks for any suggestions.
I support this request; Many topics on the board cover erratic behaviour with JJ, and ppl return their device to no avail. Swopping to another operator often helps. The issues SEEMS to be a poor UMTS reception with a given SIM or location, and this results in JJ trying to connect to UMTS or even latching on to UMTS but with an abysmal signal. After more than 15mins (annecdotal) of this is fails to ever go back to GSM without a reboot.
Solution is to turn off UMTS, but that's darned inconvenient cos you OFTEN want 3G speed (mail, RSS, google/surf).
Here's a way forwards; can someone tell us what reg entry gets changed when we select GSM vs UMTS? I will then write a couple of .reg files that can be launched from iLauncher (or whatever). Buzz coule probably write a switching app like he did for BT.
i have the same problem
When i use my Universal at home, there is pretty low level of UMTS/WCDMA signal and full level of standard GSM signal. By default Universal changes between those two sources automaticaly. But in my case, the quality of WCDMA signal is often varying just around critical level. So the result is that Universal changes band to GSM and back. And then again. And again. And... Due this, there is sometimes not possible to make data connection, because Uni is so much occupied by changing bands back and forth...
I would like to find a better solution, than select only GSM manually in phone settings. Especially because i have to unselect it manually every time when leaving home :-(
Is there any way to set treshold value (i expect increase it) for automatic switching between WCDMA and GSM?
I still do not know how to switch from UMTS to GPRS and back
with some API function (or AT command) on the device.
If I get these Infos from someone that would be great.
Then I could write a tool that checks the signal quality
and the network status and if UMTS signal is too low
it will activate GPRS.
I think this can be done with RIL API but have not found
any infos.
Houser
Anything new aobut this umts switch problems??
I do have the same problems, often i am unable to make calls, always when umts is on...
would be happy to hear something,
thomas
craigiecraigie4 said:
I support this request; Many topics on the board cover erratic behaviour with JJ, and ppl return their device to no avail. Swopping to another operator often helps. The issues SEEMS to be a poor UMTS reception with a given SIM or location, and this results in JJ trying to connect to UMTS or even latching on to UMTS but with an abysmal signal. After more than 15mins (annecdotal) of this is fails to ever go back to GSM without a reboot.
Solution is to turn off UMTS, but that's darned inconvenient cos you OFTEN want 3G speed (mail, RSS, google/surf).
Here's a way forwards; can someone tell us what reg entry gets changed when we select GSM vs UMTS? I will then write a couple of .reg files that can be launched from iLauncher (or whatever). Buzz coule probably write a switching app like he did for BT.
Click to expand...
Click to collapse
HKLM\SOFTWARE\OEM\UMTS
OPMODE=0/1/2 (AUTO/GSM/UMTS)
I've been having internet troubles since i got my Hero a few weeks ago.
It seems to jump between '3G' and 'H' when I use any applications using the internet. This means that pages often fail to load/download, or appear slower than 2G connection speeds.
I think this is because I'm in an area which can just about receive HDSPA speeds sometimes, but not consistently, so I was wondering if there's any way to set the internet to stay at 3G and not attempt to connect to HDSPA? When I'm in areas where the best speed possible in 3G, the internet is infinitely faster than when it's jumping from 3G to H and back.
Thank You!
I'm not sure on the phone itself but from a network perspective you would need to ask you phone provider to change your QOS on the HLR (network control and provisioning) to a non HSDPA entry, eg t-mobile uk QOS 1201 = HSDPA 3.6
it doesn't work that way (the hlr qos profile). you can only set the maximum speed there, not the RAN technology which is used. i don't think there is anything you can do, the phone attaches to the best server (=cell with strongest signal), and if that cell supports hsdpa it is used for data transfer. as hsd(p)a is only an "addon" for umts i don't think that your connection would be better on the same cell, even if you were able to force umts usage. bad radio reception is bad radio reception... it is not uncommon that a stable EDGE connection works better than a weak umts/hspa signal, have you tried switching to 2g?
kendong2 said:
it doesn't work that way (the hlr qos profile). you can only set the maximum speed there, not the RAN technology which is used. i don't think there is anything you can do, the phone attaches to the best server (=cell with strongest signal), and if that cell supports hsdpa it is used for data transfer. as hsd(p)a is only an "addon" for umts i don't think that your connection would be better on the same cell, even if you were able to force umts usage. bad radio reception is bad radio reception... it is not uncommon that a stable EDGE connection works better than a weak umts/hspa signal, have you tried switching to 2g?
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Click to collapse
of course you can, thousands of sims on networks are unable to use hsdpa because of a low qos, on t-mobile's uk system if you do not provision the web and walk plus SOC on the account the service order does not go through and they are unable to use HSDPA. I dont have a HSDPA qos and I dont get a H but if I use the sim that came with it I do.. best thing to do is give the networks tech support a ring with some times and locations and ask if they can look at what ever reporting system they use and look at network statistics at the time. Best to look at the sgsn;s and look at the stats at that point.
It doesnt matter if the cell supports hsdpa, hsdpa on the cell itself is only a capability to go back through to the msc. a footprint on a 3g cell will keep the closest strongest users when it hits max capacity, if you are on the outskirts you ill lose out.
the more you complain to the provider the qucicker they add some higher bandwidth lines to th local exchange or hub..
Might simply be a congested site, if so it should report itself...
naughty naughty trx
ahem... hspa is RAN (as in Radio Access Network) technology. it is applied to the communication between the handset and the node b, not anything behind the node b (not sure whether the rnc needs to be aware of it, but that's it, no msc involved). i am not sure whether the simcard needs to be hspa capable, but i have never heard of it. and i do provision sim cards for a living...
kendong2 said:
ahem... hspa is RAN (as in Radio Access Network) technology. it is applied to the communication between the handset and the node b, not anything behind the node b (not sure whether the rnc needs to be aware of it, but that's it, no msc involved). i am not sure whether the simcard needs to be hspa capable, but i have never heard of it. and i do provision sim cards for a living...
Click to expand...
Click to collapse
You are rightt hsdpa as a technology does get implemented between the mast (node b) and the handset.. what is added between the RNC and the node b is the LUB this is an added control mechanism, this kinda makes sure no data is loss occurs when the node b's buffers are overflowed! this is not a fool proof system, RNC? it could be a SRNC controller,, anyway you are right in what you say but as i have worked within this area i do know that when i was saying "SIMS" I didnt mean the actual sim itself i was referring to sims with old HLR profiles that cant access hsdpa! most pay as you go sims cant on tmob uk this stops them going £1 a day unlimited handset internet and hammering the sim in a dongle!! Im a big fan of provisioning btw! geeky as it sounds the complexity of mass provisioning failures interests me!
I have been using jio 4g for past 2yrs. The internet connection was good. But for the past 6 months I am facing frequent disconnection of the internet. So I go into flight mode activate and deactivate it again the net connection will be good for a minute and then it drops again to b/S. Frustrated I changed the SIM. But same problem. The bio customer care says it to update firmware! Which was not available and at last they told me to get the mobile serviced. So I swapped the SIM to another mobile and checked. There was no problem in that mobile. Please help me. Whether it is due to SIM or the band problem with mobile. I am using a stock firmware
Ps. Even I resetted, rooted
Set the network type or RAT or network mode to LTE (4G) only, then the phone should stay on the signal even when the signal is low for a second, around -120 rsrp (signal), specifically it should normally follow the parameters sent by the network: qRxLevMin (it is half the rsrp), qQualMin (sometimes, it is the signal quality), sNonIntraSearch, ThreshServingLow (both are ranges around qrxlevmin, one for entry threshservinghigh, one for exit). These parameters should nornally not be followed with LTE (4G) only. But only if the signal drops below the limit for a second. Else, it is a waste of resources, both for you (battery, etc), and the network, though the network can deprioritize cell edge (low signal) users.
To do so, there are extended network modes (for sim 1) in a menu that comes with Android, it is called 4636, Testing, Phone info, Device info, etc. There are apps that open 4636 without root, that offer: mode selections, lte only, anything cellular related that opens 4636.
Hold the phone on its top, not its bottom, for testing, the primary reception antenna should be at the bottom for A 2016, you can check this in *#0011#, it is "ant rsrp diff", it is positive when the primary reception antenna is better, negative when the diversity reception antenna is better, the diversity antenna should in most cases power on when the cellular is in use and start measurement, in contrast to the primary that's just switched on.
The signal can be measured in *#0011#, rssi is the signal strength of the frequency, the signal strength of intra freq (same frequency) neighbors (other cell towers etc) may differ slightly anyway because it's missing a decimal point; rsrp (good maybe at least -120, get it closer to -1) is approximately the signal strength of the cell, it is a few antennas in the long rectangular boxes on a cell tower, note that it is the measurement of the reference signal not the data that is being sent to your phone; rsrq(good maybe at least -15, best -1), sinr (good maybe at least 0, best 40), are signal quality. The "registered plmn" is the currently connected operator (mobile country code and mobile network code), if it changes (different compared to the sim), the signal is low! The "PCI" is the currently connected cell, note that there are only ~500 of these, so to identify the cell you can use both PCI and TAC (region), if the pci changes and the signal strength drops, well, the signal dropped and a reselection is made to an inferior cell, which can then drop data... in this case contact your mobile network operator but they might not make changes if it only affects a few users. You may try to lock band/etc to the good cell that sometimes drops in quality for a second but overall better than the neighbour cells.
Here's a short list of scenarios that can cause problems in connectivity, not all.
1: Low signal, plain old low signal. If the phone can't register VoLTE the bands that can be connected to may be restricted on some MNOs.
2. The antenna is closed and this causes low signal.
3. Low signal of the serving cell, the signal of an inferior neighbour cell matches (above parameters!), the phone changes to another antenna on a cell tower, quality drops and so does the connection. On another cell tower or there are 2 antennas on 1 cell tower, for example 1 facing the azimuth 180 degrees, another 270, the phone being in 215 degrees is unfortunate!
4. The antenna is open and receives interference (and reselections, sometimes good) from neighbour cells.
5. Good signal but it has been echoed a bit too much.
6. Reject causes and others, where the connection has been disconnected for some reason. Probably not in this case! It is viewable in *#9900# > Take cp log > copy to internal sdcard. It is in the /internal storage/log/LitmusLog. Scroll down to the reject cause section, those are error codes.
None of these codes/volte are working: The CSC is not applied correctly! Flash stock rom and open the stock recovery or copy /system/csc/...csc.../system/ to /system/etc/.
I do not recommend anything EFS/PIT, making a backup of efs is OK!
Hi,
I am facing the same problem with a7 2016 with JIO sim.
The mobile is purchased in dubai and when insert jio sim in india, was not able to use volte service.
So I flashed official indian rom. Everything is fine except net speed. Net speed between 1-5am is very fine but in day time speed reduces.
Everytime i have to restart data to use net but after a while same problem occurs.
Tried in both sim trays. I am using single sim in mobile.
Pls provide a solution.
Regards
//aftab