Hi, anyone tried connecting to 3G in a non 3G coverage area and the connection automatically switch itself to GPRS instead of EDGE, even if EDGE is available in that area? I wanted to connect my device to EDGE if 3G is not available and not to GPRS. Pls advice... Cheers!
Hey,
The way mobile networks and handsets work is the phone will always choose the highest available connection speed possible and the network based on capacity and available resource will assign the mobile what it can. That's why a phone will always look for a 3G network before a GSM one. When the phone initiates a packet connection to the network it includes a message which tells the network it's capability such as EDGE supported, what class of GPRS capability (4 slots down / 2 up etc...) and then the network based on this message assigns the phone a resource. Most networks nowadays have enough resource to give you a fairly good connection. For example if you support EDGE you will be given EDGE assignment (8QPSK instead of 4GMSK) as the ways the data is scheduled in the network is no different between GPRS and EDGE only the connection between the handset and network is faster.
What actually happens when you change from 3G to GPRS/EDGE is you drop the connection in 3G (move out of coverage) and based on the neighbouring channel list you received off the 3G cell you look for the most suitable GSM cell. Now this cell may or may not support EDGE but in either case the handset will PRACH on the cell, the cell with then ask the handset to authenticate and in this message you send your handset capability and also information about the last RNC/PCU (in this case the one connected to the 3G cell) you were on. The new PCU then signals with your old one and re-routes the data in the backbone of the network to you on your new cell. There will be data loss but the higher layers (application) should ask for re-tries for the missing data if it's TCP data.
In summary your connection priority (if the network supports all these technologies) is: HSDPA > UMTS (3G) > EDGE > GPRS > HSCSD > CSD
Hopefully this answers you question and adds a bit of extra info...
EDIT:
P.S. Not many networks support EDGE at present but most have plans to support it in the next 12-24 months.
Gav
How do you know you are on GPRS and not EDGE??
Hi Eeter,
I don't think there is any indication on the device You could tell my doing a speed test. If you are on a GSM network where you know EDGE is used then more than likely you will be using it instead of GPRS.
Gav.
There is an easy way:
1. Install the fieldtest utility
2. Go into a data session ( streaming radio ....BBC or others )
3. Check the Fiedtest EGPRS page and look for the downling coding
4. If it shows a CS1 or CS2 it is GPRS. If it shows MCS5 etc.. It is EDGE
Checking speed only is misleading. EDGE can be slow sometimes and the speed depends not only on the air interface but on the core internet side too
Hi eeter,
Yeah I agree that a speed test could be miss-leading.
Checking if you are using a MCS instead of CS will say for sure you have an EGPRS connection.
Gav.
Related
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.
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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
Just picked up a Hermes 8525 off of ebay.
While upgrading to the latest WM 6.1 roms available - I have been picking up the 3G network in my area here in Montreal.
I do not have a 3G sim card, and do not plan on using any of the data features either. I pretty much just use it as a regular phone - surf via wifi. Am I actually on the 3G network ??
I also do not have a 3G plan with Rogers. Is there any benefit to 3G if just being used as a regular wireless phone ??
If not being used for any data features, etc - will there be an additional charge applied ??
Should I just force the phone to GSM network only - instead of auto ??
Any feedback greatly appreciated
Have a good one
3G is data and voice. So, even if your not using the data plan your voice connection still auto connects to 3G network or Edge.
You wouldnt get charge for data as long as your 3G data connection is disabled.
You could force it to use a specific band (i.e. 850/1900 mhz) but you might have a bad connection on some areas since the phone auto connects to stronger signal. Hence better (sometimes) voice quality.
hello,
after searching on "3G" in the forum, i seems that the problems are just the opposite to my question, they all want 3G to be turned off.
Now I want to connect to 3G (with the "G" icon on the staus bar).
My problem is that it always connect on "edge", with the "E" icon in status bar and when I want to make a video call, it always says that there is no connection to 3G so I can't make videocall.
Anyone knwos how to activate 3G?
I looked into the connections, but I don't want to mess in it without knowing what I do.
BTW I'm in Europe (Belgium).
Thanks
You fell into the same trap I did when I first got a Windows Mobile phone.
G means GPRS and is the lowest, simplest connection speed.
G = GPRS. "Normal" internet speed (9.6-14.4kbps)
E - Edge. "Enhanced" internet speed (normally 48kbps, but can be higher)
3G = 3G internet speed (128-384kbps). Also allows video calls.
H = HSDPA. "Mobile broadband" speed. (1.8Mbps, 3.6Mbps or 7.2Mbps depending on operator).
You'll want to go to:
Start > Settings > Connections > Advanced Network
Make sure that HSDPA/HSUPA is enabled
From then on, it depends on the signal in your area. If you find that you're having a problem getting and maintaining a 3G or H signal, you might need to get an updated SIM from your operator. I got a new SIM from O2-UK and it solved my connection problems immediately.
I see that HSDPA/HSUPA is enabled.
Could it have something to do with the settings in connections (instead of advanced network settings)?
I will also check with my provider (sim card)
Thanks for the reply
i cannot connect to the internet not using wifi. i do however h an H symbol next to my signal. i dont get why i have the hsdpa but cannot connect. i've tried anything i can think of.
*i can't turn data connection on in my comm manager, it automatically disconnects and says wap.cingular not working or gprs not working somthing like that.
*in the connection settings i pick media net wich is automatically picks att but still won't
*in settings/personal/phone i left if auto defualts for bands
*settings/connections/advance network i even tried to put it to hsda ONLY won't work
the only new lead im getting is this Zenith post saying he got new sim card so now it's working. that's all im getting at now. but im even skeptical about that
If you are not getting the 3G or H icon then you either have no coverage or an incompatible SIM.
If you can't connect to the internet you either have incorrect settings on your phone, or your network aren't allowing you on their APN.
Suggest in all cases phoning your network to get clarification.
artesea said:
If you are not getting the 3G or H icon then you either have no coverage or an incompatible SIM.
If you can't connect to the internet you either have incorrect settings on your phone, or your network aren't allowing you on their APN.
Suggest in all cases phoning your network to get clarification.
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Click to collapse
you wouldn't believe how i found out i had no internet. they say'd it was in the system but it was disabled in thier system. i put in my brothers sims and his work just fine. so i told them to look at whatever his plan is and they switch to what he had. anyways long story short i found out not my settings bc you just auto configure it connectin wizards, and wasn't sims card, it was stupid att. i was getting the H icon but not an H on my signal. anyways its all done now. thanks again guys
Hi.
I have an HTC Touch HD on the UK 3 Network.
It works fine with texts and calls n 3g but whenever I need data for an app etc it ignores a great 3g signal and tries to connect on HSDPA instead.
now this might not seem like a problem but it often switches from full 3G bars to one bar on HSDPA to check my email. this can take 5 to 10 seconds when it could have just done it on 3G.
what gives? am i using the right settings?
start/settings/phone/band
Network Type "Auto"
GSM/UMTS band "Auto"
when i was on Vodafone it would stay on the best choice ie HSDPA instead of all this swapping about.
I hope this is the right place to ask. not a major problem just a frustration.
thanks
don
In common with many (all?) of the five networks, 3UK has recently switched their handsets from staying on HDSPA to "only" 3g, but automatically changing to HSDPA when data traffic occurs.
HSDPA demands extra bandwidth to the cell. There might be a second or so delay while the handset re-negotiates the extra protocol, but it's done to give extra capacity on the cell, allowing more space for 3G voice calls, while ensuting your data speeds aren't affected by push-email or similar low-bandwidth devices using an always-on HSDPA protocol.
In short, it's completly normal and pretty standard nowadays. Keep your phone on Auto/3G, you can't force it to HSDPA only.
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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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...
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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!