ok, since things are a little ambiguous with conencting to 3 with an XDA2...
as I understand it, 3 can be accessed via WCDMA (at least, that's what my 3G phone says) and via 2.5G, so, simply, is there any way you can connect to 3 from a Himalaya, does it require a certain type of sim from 3... etc etc.
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.
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
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)
Here in the US I am using T-Mobile, wich doesn't have 3G yet. So, I probably don't have a 3G sim in my Hermes, and everywhere I go, I always get only a G next to my phone icon. However, when I went to Toronto, Canada, this past week, the G changed to a U. Does that mean:
1) UMTS network was detected, but all it did was detect it, and keep using GSM?
2) UMTS network was detected, and I was able to connect to it, because the 3G in a 3G sim cards is for internet access only,
3) the U is for internet connection availability only, and doesn't affect the cell voice phone part of my TyTN?
or
4) I somehow got a 3G compatible SIM card, and had I wanted to, could've been charged $10 every 8 to 10 seconds for downloading REALLY fast (I get charged $10US a meg if I use web outside of USA)
Hello rassah,
In order to have a 3G service you do NOT have ot have a 3G SIM (also known as USIM). The network is backward compatible and will allow you to use whatever your SIM card (or the network) authorized you.
I am also TMO subscriber and in some countries I could use UMTS and in others only 2.5G (GPRS/EDGE). Technically you have no limitations to do so so its up to the commercial arrangements between TMO USA and the other operators.
So the bottom line:
a. Your device detected UMTS and the network allowed your device to be attached to the 3G network (hence you saw the "U").
b. You probably have a SIM and not USIM (like you mentioned TMO still does not have 3G network ready for commercial use).
c. It is perfectly OK technically to connect to a 3G network even if you have 2.5G SIM card (pending you are authorized by the network to get such a service).
You can do a simple test next time you are in Toronto or other place where you see the "U". Go to www.dslreports.com, they have speed tools, try to perform a speed test and if you are connected with "U" you should get 3G speed results (again, depends on the network and the quality of the signal.. you will see a result of something between 200k to 300k i would guess)
PS: You are right about the cost per meg. But look at the 3G speed as you get what you want but just faster so the bottom line is - you are being charged the same as 2.5G just get work done sooner
i kind of had a question in general about using data over WAP..
IF i wanted to use WAP over GSM would i be charged for airtime minutes or Kb.
its not using the GPRS network, and i want to kind of simulate a "dialup modem." In that sense i know it would be like 14.4kbps (really slow)... but at the same time would i be able to use WAP as "minutes" instead of "data."
if not wap is there any technology where i can do that?
Thanks!
bumppy bumppy
I think you should distinct two things : protocols and the physical networks that supports them.
WAP is a protocol that adaptes wireless physical links to packet networks (to be trivial), it could be used with any physical link (GSM, 3G or even WiFi for instance) but is in fact historically used with GSM in the GPRS part (new 3G networks are more and more packet and native IP oriented) :
h t t p://en.wikipedia.org/ wiki/ WAP
Then, if you're using GPRS you're paying data charges (in volume), if you're making a voice call you're paying minutes of comms (in duration then).
So your real question is : can I exchange data with a GSM/Voice link (without using GPRS) and the answer is "yes but you really dont wanna do this" (reaaaaaally slow : 9.6 kbs) and like you've said yes it's possible because your phone is in fact a dial-up modem. It uses the AT commands set (cooked in the GSM fashion) like many Telcos equipment :
h t t p://en.wikipedia.org/ wiki/ Hayes_command_set#GSM
But you'll need a piece of software to access these functions : on old Nokia I remember it was possibles to do it in the field mode (after typing a certain successions of keys), on WinMo you can emulate AT commands sent to the Radio Interface Layer and then control what you want to do, you should take an eye there :
h t t p://stackoverflow.com/questions/997325 / directly-accessing-the-modem-in-windows-mobile
and look into the MSDN Libray for Windows Mobile
Once you've got access to these commands, you can initiate a dial-up connection, exactly like you did when you've got your old and slow bipping modem plugged on the phone ! You then need a number to call that can route your call to an equipment that gives you access to the Internet (in one word a Dial-up ISP like in the old good times)...
In Windows Mobile (at least on my old HTC phones) it was possible to initiate a CSD connection (CSD stands for Circuit-Switched Data) that means a connection using the 9.6 kbs link like call to connect to your carrier's data network...I'm not sure it's still working nowadays due to the new architecture of GSM and 3G networks...You can anyway take an eye to (for WinMo again) :
h t t p://technet.microsoft.com/ en-us/ library/ dd261898.aspx
Finally on Android....I've not tested that yet (a bit useless in regard of my shining new high-speed HSUPA connection)
Two questions then : what is your phone (brand, model, OS) ? and what do you wanna do (which number do you want to dial-up) with that ?
Good day,
I've seen this issue discussed but it didn't quite fit my experience in all regards.
So here's the story, SGS2 bought from Orange Romania (Branded) then unlocked with Chainfire's app and used on Vodafone Romania.
When switching to WCDMA only and using the packet data, the internet speed is overall slower than my previous Galaxy S, most of the time pages just taking ages to load or even failing to load due to timeout, even though the H+/H/3G signs appear (depending on the area) and seem to be communicating.
Also call drops have been encountered in areas with full coverage (where my former phones never has problems).
I must mention that:
1. The APN was fully configured for the SIM's network.
2. I tried all kinds of firmwares (KG6,KG5,KG3,KG2,branded Orange Romania firmwares,branded Vodafone firmwares) and the results are the same, it just can't keep the connection up, probably due to constantly changing bands.
3. I tried disabling "fast dormancy", didn't help.
4. I tried using the KD5 modem that I have read that it sort of fixes this bug, still connection drops.
5. Being in areas with bad coverage is out of the question since my former SGS1 and my Nokias never had such problems in these exact same places.
Could it be due to the branding process and the files Orange inputs into the device? Normally I should be able to unlock any carrier branded phone and use it on any other network with no further change but the APN for mobile internet (at least that's what I did on my SGS1 and it worked fine).
Any word of advice would be welcome and thanks in advance to the ones that bother to read this wall of text through