Re: Recommendations for a data-only GSM/UMTS device in USB stick ff
Am 19.11.2011 um 22:51 schrieb David Pottage: On 15/11/11 01:24, Michael Sokolov wrote: Hello Om community, Given that the GTA04 contains an off-the-shelf UMTS module and, if my understanding is correct, truly off-the-shelf GSM/GPRS/UMTS modems in the consumer USB stick form factor have been used during the BeagleBoard prototyping phase for the GTA04, I've figured that someone here might have some experience with / knowledge of these USB sticks, hence me asking here... [snip] * I need this device to be capable of placing old-fashioned data calls, not just Internet access. By old-fashioned data calls I mean the arrangement where one dials a number from the mobile device with ATDnumber (no semicolon at the end, making it a data rather than voice call), and the number being dialed is a POTS land line with a plain old analog modem answering the call. I want to be able to connect to my personal data center from remote locations bypassing the Internet. I think you will find that it is imposible to make data calls to an analoge modem. The reason is that GSM and it's sucessor standards are inherently digital, and are derived from ISDN telephone standards, so nothing in your phone or in the phone network will create tones that will be understood by an analogue modem. The service he is looking for is called CSD: http://en.wikipedia.org/wiki/Circuit_Switched_Data There is indeed a (DSP based) modem in the network that converts your digital data to analog tones. The same principle is used if you send DMTF or a Fax through (digital) GSM. It will be transported through efficiently encoded through digital networks until it comes close to the destination. There, it is converted into analog signals (maybe PCM encoded) so that your Plain Old analog Telephone or Fax modem can finally receive it. And you can hear the tones or beeps. It should be listed in the data sheet of the USB modem if it supports this mode on the mobile end. And, the network operator should be able to tell if he still operates such a gateway to analog/PCM phone networks. -- hns ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Recommendations for a data-only GSM/UMTS device in USB stick ff
On 15/11/11 01:24, Michael Sokolov wrote: Hello Om community, Given that the GTA04 contains an off-the-shelf UMTS module and, if my understanding is correct, truly off-the-shelf GSM/GPRS/UMTS modems in the consumer USB stick form factor have been used during the BeagleBoard prototyping phase for the GTA04, I've figured that someone here might have some experience with / knowledge of these USB sticks, hence me asking here... [snip] * I need this device to be capable of placing old-fashioned data calls, not just Internet access. By old-fashioned data calls I mean the arrangement where one dials a number from the mobile device with ATDnumber (no semicolon at the end, making it a data rather than voice call), and the number being dialed is a POTS land line with a plain old analog modem answering the call. I want to be able to connect to my personal data center from remote locations bypassing the Internet. I think you will find that it is imposible to make data calls to an analoge modem. The reason is that GSM and it's sucessor standards are inherently digital, and are derived from ISDN telephone standards, so nothing in your phone or in the phone network will create tones that will be understood by an analogue modem. Having said that, there should be no problem making data calls to another GSM device or a digital trancever on the end of an ISDN phone line. Given your other requirements for off the shelf hardware, I think your simplest solution would be to buy a mobile phone with a data port, and learn how to use that port as a GSM modem. For example I used to work for Nokia, and I know that with their phones, if you put them into PC Suite mode they will respond to AT commands on their serial/usb ports and let you do dial up internet to your ISP, or any other phone number. You may find that your current phone does what you need. -- David Pottage ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Recommendations for a data-only GSM/UMTS device in USB stick ff
On Sat, 19 Nov 2011 21:51:33 + David Pottage da...@electric-spoon.com wrote: On 15/11/11 01:24, Michael Sokolov wrote: snip * I need this device to be capable of placing old-fashioned data calls, not just Internet access. By old-fashioned data calls I mean the arrangement where one dials a number from the mobile device with ATDnumber (no semicolon at the end, making it a data rather than voice call), and the number being dialed is a POTS land line with a plain old analog modem answering the call. I want to be able to connect to my personal data center from remote locations bypassing the Internet. I think you will find that it is imposible to make data calls to an analoge modem. The reason is that GSM and it's sucessor standards are inherently digital, and are derived from ISDN telephone standards, so nothing in your phone or in the phone network will create tones that will be understood by an analogue modem. I don't know about doing that with GSM but it 'sort of works' over VoIP which is also inherently digital. I had occasion to help a guy out with transitioning from Windows Vista to Ubuntu (iirc) and he only had Dial-Up. I only have VoIP and have done for years but did manage to figure out the proper methods to use for him to be able to use his ISP when they wouldn't support it. I had a friend who also uses VoIP test a kermit connection with me. It worked but it wasn't very reliable or error free. That wasn't the goal though, initially I just wanted to verify that the hardware modem would work. After verifying it worked I did manage to surf the web albeit at lower than the 56k speeds the modem is capable of but it did work. I probably could have fiddled around with asterisk a bit more and utilized fax instead of voice but I was only interested in determining the proper login procedure for his ISP. Having said that, there should be no problem making data calls to another GSM device or a digital trancever on the end of an ISDN phone line. Given your other requirements for off the shelf hardware, I think your simplest solution would be to buy a mobile phone with a data port, and learn how to use that port as a GSM modem. For example I used to work for Nokia, and I know that with their phones, if you put them into PC Suite mode they will respond to AT commands on their serial/usb ports and let you do dial up internet to your ISP, or any other phone number. You may find that your current phone does what you need. Good luck in your endeavors. Brian ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Recommendations for a data-only GSM/UMTS device in USB stick ff
David Pottage da...@electric-spoon.com wrote: I think you will find that it is imposible to make data calls to an analoge modem. The reason is that GSM and it's sucessor standards are inherently digital, and are derived from ISDN telephone standards, so nothing in your phone or in the phone network will create tones that will be understood by an analogue modem. There is a gateway somewhere in the network, probably at the point where the mobile network connects to the old PSTN, that does the trick. Just like for voice calls some gateway has to convert between the 9600 bps or whatever codec is used in GSM and the classic 64 kbps of the wireline world, that gateway is apparently also capable of acting as a voiceband modem emulator, handling a data call on the GSM side and doing V.32 or whatever modem tones on the wireline side. I have personally used this feature back in 2004-2005 timeframe. I had a Mot V66 phone on T-Mobile USA, just like I do now, and I was able to connect the data cable to my phone, run minicom or similar on the laptop, and type ATDnumber, where the number was that of a land line with a USR Courier V.everything modem. It worked, connected at 9600 bps. I want to do the same thing again. Hopefully whatever gateway makes it work hasn't been dismantled, although I will likely be its sole user... Given your other requirements for off the shelf hardware, I think your simplest solution would be to buy a mobile phone with a data port, and learn how to use that port as a GSM modem. For example I used to work for Nokia, and I know that with their phones, if you put them into PC Suite mode they will respond to AT commands on their serial/usb ports and let you do dial up internet to your ISP, or any other phone number. You may find that your current phone does what you need. Yes, that's exactly what I used to do, using an identical phone. But it's a very clumsy solution, the data cable is bulky and inconvenient, and the Mot V66 makes it impossible to connect the data port and external power at the same time. I was wondering if I could take one of those cell modem USB sticks that a lot of people use nowadays for Internet on the road, and talk AT commands to it. Then I could try doing the ATDnumber from it: if it works, it would be a lot more convenient than using a phone and a data cable. The data-only cell modem devices in the USB stick form factor have the additional advantage of being completely batteryless, taking power from the laptop's USB port and nowhere else. It's a little easier for me to tolerate using a device whose GSM firmware I have no source for if that device is incapable of having any of its circuitry powered up except during those brief moments when I plug it in. MS ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Recommendations for a data-only GSM/UMTS device in USB stick ff
Dne 15.11.2011 02:24, Michael Sokolov napsal(a): Oh, and before anyone accuses me of being a hypocrite and hoarding or not-sharing the TSM30 FW source which I have finally located, let me reiterate I *do* freely and readily share this source with everyone in the world, just not via the Internet. Not via the Internet because my current FTP server doesn't have enough disk space and my external Internet connection is too slow. Instead I am offering a CD-R copy by snail mail to anyone in the world who wants one. Just give me a snail mail address (PO Box / anonymous / whatever, I don't care) and I'll send a CD-R copy out the same week, maybe even the same day. Anyone who would like to see it made freely available via the Internet is welcome to get the CD-R copy from me, then host it on his/her own server: everyone in the world but me uses newer HW for which half a GiB is nothing, and I'm sure that most people in the world have faster Internet connections than my 384 kbps symmetric. If you really have that sources, you can upload them on some public file sharing website and post link here on mailing list. Of course, you are going to lose control over this files and broke some terms of service rules, but you don't recognize this bourgeois rules, right? For inspiration, there are links to leaked TI Calypso documentation hosted on some leaks-friendly file sharing service: http://wiki.openmoko.org/wiki/TI_Calypso_D751992AZHH You don't really need to host files on your personal FTP server, if you don't need to keep access logs for let's say statistics purposes, of course. And I do have hardware docs for both Calypso and Glamo on my public FTP site: they are small enough, unlike the *gigantic* TSM30 FW source and the associated development environment. (The latter is for Windows unfortunately, and is required to compile the darned thing, until someone does the massive work to port it to compile with gcc binutils toolchain.) MS ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
