Database Users

Simultaneous voice and data

I'm wondering if the device and/or any providers allow or support simultaneous voice and data connections. For exampleI would like to have a voice call open and be able to browse the web or run a custom app that connects over the network to my application server. Does the device and/or providers support this capability? Thanks.

Short answer is that they can't.
GPRS phones come in three classes. Class A which can do simultaneous voice and data. Class B is GSM and GPRS attached simultaneously but can only use one. Class C is either GSM or GPRS attached, but not both.
The radio rwesource allocation on Class A makes it impossible to implement using only one radio module. You have to use two RF front ends acting independantly. It is not economic to do this, also the power consumption would be too high.
The standards have introduced a "Simple Class A", or Dual Transfer Mode device that simplifies the radio resource allocation. You get a half rate Voice timeslot and a half rate GPRS timeslot in succession. This is easily (or more easily) implemented on a single radio module.
The downside is that you get crappy voice and slow data.
UMTS can support simultaneously voice and data as the radio resource allocation mechanism was designed to do this from the outset.

What UMTS devices are available
So, this begs the questions, what are the available UMTS devices and service providers. Thanks.

Can someone plse explain difference between GPRS & GSM

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

Any way to set 3G as permanent internet so it doesn't go to HDPSA?

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?
Click to expand...
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!

[Q] Option to use only 3G NOT HSPDA

HI all!
Right now I am using [Build][10.12.2010][NexusHD2-FRG83D V1.8 PPP+RMNET][Kernel: hastarin r8.5.3_oldcam] and that is quite ok for me.
However I havent found anywhere on that build an option to disable HDSPA speed.
What I would like is accept 3G but disable HSPDA. Now I only have a change to disable 3G totally and only get 2G. Basicly area where I live is keeping me a situation that phone is very often trying to connect HSPDA but then changes is 3G speed. It causes me time&battery drain.
I have found a solution to force phone only use 3G but that is what I wanted. 2G and 3G are ok but I want to disable HSPDA.
Anybody could help me?

Up, Up... anybody have same kind of need?

i also need same help regarding this, reason is my data plan only use 3g (umts) and not 3.5g (hsdpa)... but my android always switch 3g to hsdpa back and forth and drain battery much faster
is there any tweak/program/widget/application that can enable 3g (umts) only?
windows doenst have this problem cause in winmo i can switch the option easily (enable/disable hspa)... but android dont have this kind of thing

I have the same problem. I don't even have HSPDA where I live, yet it tries to connect, fails, and then connects to 3G. It's a very time consuming processor to wait for the phone to do this when I am just trying to load a website.

Yes.. maybe it will not drain much memory but.. who wouldn't want a fast internet..

Afaik Hsdpa uses the same radio towers (or whatever the name is) as Umts... just different software. so there should be no battery drain caused by this.

This mite help you
1. Go to your dialer
2. Dial *#*#INFO#*#*
3. Click 'Phone information'
4. Scroll down to the first dropdown selection and set according to your preference below...
For simplicity, there are two main types of cell carriers, GSM and CDMA.
The following popular data communication technology is associated with each cell carrier type:
GSM = GPRS (2g), EDGE(2g), UMTS(3g), WCDMA(3g), HSDPA(3g) {Cell Carrier examples: AT&T and T-Mobile}
CDMA = CDMA*(2/3g) EV-DO(3g) WiMax(3/4g) {Cell Carrier examples: Verizon and Sprint}
Now that the general stuff is out of the way, here's my take on the Preferred Network types:
WCDMA preferred - The GSM phone is capable of using both 2G and 3G data communication and when signal strength is low 3G is favored more.
GSM only - The GSM phone is capable of using only 2G data communication. When the 2G signal is too low you get nothing at all.
WCDMA only - The GSM phone is capable of using only 3G data communication. When the 3G signal is too low you get nothing at all.
GSM auto (PRL) - The GSM phone is capable of using both 2G and 3G data communication and when signal strength is low 2G is favored more. This one is a bit confusing to me since PRL is associated mostly with CDMA technology and not GSM technology.
CDMA auto (PRL) - The CDMA phone is capable of using both 2G and 3G data communication and when signal strength is low 2G is favored more.
CDMA only - The CDMA phone is capable of using only 2G data communication. When the 2G signal is too low you get nothing at all.
EvDo only - The CDMA phone is capable of using only 3G data communication. When the 3G signal is too low you get nothing at all.
GSM/CDMA auto (PRL) - Some phones are equipped with both GSM and CDMA capabilities. This setting appears to just have the phone attempt to stay connected to the data communication type that works the best. (Maybe the Samsung Galaxy S will take advantage of this???)
Unknown - If none of the above fit or the phone is acting weird as far as connecting to the carrier, you will see your preferred network type is set to this
Click to expand...
Click to collapse
Source http://www.google.ie/support/forum/p/android/thread?tid=6a327a95211ac789&hl=en

domenukk said:
Afaik Hsdpa uses the same radio towers (or whatever the name is) as Umts... just different software. so there should be no battery drain caused by this.
Click to expand...
Click to collapse
uhh... maybe you dont catch what us mean....
when umts change to hspda (icon change from 3g to H) then it use battery power.. in my case i use 3g (umts and not 3.5g or hspda )data plan only... but android keep searching hspda signal and THIS is when battery used the most (the process) and EVEN when my area have 3.5g covered but because i use 3g only data plan... then the back and forth process (3g<->H) will kep coming and rdrain my battery fast
so... we look for any kind of workaround so our android keep stay in 3g (umts) and not drain any unnecessary battery power searching for hspda
btw sorry for my english

agarp said:
This mite help you
1. Go to your dialer
2. Dial *#*#INFO#*#*
3. Click 'Phone information'
4. Scroll down to the first dropdown selection and set according to your preference below...
Source http://www.google.ie/support/forum/p/android/thread?tid=6a327a95211ac789&hl=en
Click to expand...
Click to collapse
i use this thing before and no luck
i use "wcdma only" as the option and android still process 3g and 3.5 back and forth, maybe android "thinks" 3g/umts and 3.5/hspda as the same?? android categorize umts and hspda as one big fat 3G network
i wonder why newer os like android doesnt have this kind of feature in winmo there is an option :
disable hspa = so hspda disabled.. AKA 2G or UMTS only
enable hspa = enabled hspda, hspa, hsupa etc.. AKA 2G, UMTS and HSPDA

try this settings
CDMA auto (PRL) - The CDMA phone is capable of using both 2G and 3G data communication and when signal strength is low 2G is favored more.

agarp said:
try this settings
CDMA auto (PRL) - The CDMA phone is capable of using both 2G and 3G data communication and when signal strength is low 2G is favored more.
Click to expand...
Click to collapse
isnt cdma auto (prl) used exclusively for cdma phones? (those phones with evdo and wimax thing) and not used for our hd2 (GSM)???

C'mon how this is impossible with newer phone software??
This feature has been in WinMo and Symbian in many years!!
It is really frustrating that almost every time my phone is trying to make HSPDA connect and then decide 3G is enough and possible. It causes some delay and sometimes also timed out errors.

agreed
my android keep going back and forth between umts 3G and hspda 3.5G like some clueless kid while 2 experienced guy (symbian & winmo) laugh at him

i know this is a old topic
i have still this issue
my phone is switching to hsdpa an back to 3g after a few seconds
when the phone is connected to my slow wifi connection everything works fine and i can use it for 3 day's
when it is connected to hsdpa my battery is empty after 15 hours and the voip connection is not working properly (i need to start a ping to some server first to keep the connection alive so i can call with voip)

I just came upon this thread, but I don't have this problem, so I can't really test it out this theory. But my thought was, what if you just went into the build.prop file and edited the ro.ril.hsxpa.category settting from ro.ril.hsxpa.category=2 to ro.ril.hsxpa.category=0. I just tested it out and it never jumped from 3g to H. My only concern is that you wouln't get the fastest speed you could be getting. Test it out and let me know though.

at this moment it is not posible to root my phone (SE Xperia pro with latest firmware)
so i am afraid we need to wait to test this
but thanks for the hint

3G/4G cheap alternative, my exp

Hi everyone,
this post is useful not only to owners of a500, but tested on.
Reading of million post of using 3G/4G usb modem and lot of unhandy actions to do this work, i decide to look for an alternate things, that not sticks from tablet and will not require any hardware/software modding. I found it. Solution was MIFI router. So, there are plenty then on market, but i choose exact one Sierra Overdrive (AirCard W801) 3G/4G. Why?
Battery life est. 6 hours
Can work and charging directly from a500 USB slot.
strong signal
nice looking
also as a bonus, built-in GPS, micro SD slot, which can be shared over net, and a possibility of making small wifi local net.
In Ukraine it cost about 50usd. (Sprint edt.). I have to change software on it, because we don`t have a Sprint network. Used InterTelecom.
Some tech:
Sierra Overdrive 3G/4G
(Sierra Wireless AirCard® W801 Mobile Hotspot)
Network Technology :CDMA EV-DO REV A/WiMAX
Frequency Bands: CDMA 850/1900 MHz, WiMax 2500 MHz, GPS 1575 MHz
Antenna Diversity Support Yes
Operating System Support Windows XP, Vista, 7, Mac OS X, Linux or Anything with Wi-Fi
Operating Temperature 0 to 45° Celsius
Storage Temperature -20 to 85° Celsius
Form Factor Mobile Hotspot
System Requirements Wi-Fi 802.11 b/g
Device Dimensions : 80 mm (L) x 80 mm (W) x 15.2 mm (H), 3.15” (L) x 3.15” (W) x 0.6” (H),
Weight: 4.47 oz (127 g)
AC charger with USB port
Max Uplink Speed 5 Mbps
Max Downlink Speed 10 Mbps
Internal antenna
GPS
MicroSD slot
No receive equalizer
micro USB
Battery up 6hours.
Tested:
Iconia A500 32GB, stock. No modification done.
Sierra Overdrive 3G/4G. Sprint edition, software custom modified to support Intertelecom 3G network.
Max Uplink Speed 1.2 Mbps (3G)
Max Downlink Speed 2.5 Mbps (3G)
SD card 8gb shared over network with Acer laptop.
Network connected at 54mbit, work clearly without stacks.
Battery: Iconia connected 3G via wifi approx. 5hours 15min.
Iconia + laptop + mobile phone, 3g, via wifi, inside moving car, aprox. 3hours
GPS much more sensitive then iconia internal ones.
BTW, greatly quicker then A501 3G and more useful.
Hope was useful.
Sorry, for possible mistakes, English not my native language.

Or, if you have a smartphone that supports it (like Android), just enable the access point and use that.

Several custom ROMs for the A500 are comming with a 3g patch to support Huawei 3G USB sticks. Since you can get these sticks in combination with a prepaid SIM card for free in some countries, this is another "cheap" way to implement 3G support on a A500 (if one doesn't have an Android cell phone).
Best regards, maris

its true, but if you have.
anyway 50usd cheaper than any of wifi smartphone and much more convenient than 3G dongles via tablet usb.

just use a huawei e585

so this works kinda like a router...so where does the connection come from? sim card?

These type of devices are all over the us markets..
This included pre paid plans pay per mb plans and of course contract data plans . But as said above just get a android cell that you can ROOT.And install a tether app.
Cell plans with data are about the same price as a data only Hot spot device.. Now i am just posting the way it it in the us.. Other countries as where the OP Is i guess likely to be much different .
I Tether my TAB and Sometimes my notebook to my Cell all the time. As far as gps in iconia.. i am really not sure what more you need then the 10 or so sats i go with Co- Pilot on my iconia. in 10--30 seconds..
Very useful post im assuming for people not in the US..

mythek88 said:
so this works kinda like a router...so where does the connection come from? sim card?
Click to expand...
Click to collapse
should be prepaid or custom programmed directly. Not using sim/ruim cards.

erica_renee said:
These type of devices are all over the us markets..
This included pre paid plans pay per mb plans and of course contract data plans . But as said above just get a android cell that you can ROOT.And install a tether app.
Cell plans with data are about the same price as a data only Hot spot device.. Now i am just posting the way it it in the us.. Other countries as where the OP Is i guess likely to be much different .
I Tether my TAB and Sometimes my notebook to my Cell all the time. As far as gps in iconia.. i am really not sure what more you need then the 10 or so sats i go with Co- Pilot on my iconia. in 10--30 seconds..
Very useful post im assuming for people not in the US..
Click to expand...
Click to collapse
Here in Europe we don't need to root our phones to tether internet. If device have a tethering option ,GSM/internet providers don't block it. It would be against the law