- baseband-devel - lists.osmocom.org

900MHz packet radio?
by Paul Gardner-Stephen 01 Sep '11

01 Sep '11

Greetings all, At the Serval Project we have created a mobile mesh telephony system that currently works over wifi.

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Re: baseband-devel Digest, Vol 20, Issue 1
by Paul Gardner-Stephen 01 Sep '11

01 Sep '11

On Thu, Sep 1, 2011 at 7:30 PM, <baseband-devel-request(a)lists.osmocom.org> wrote: Hello, Thank you Dieter and Scott for your fast responses. > ---------- Forwarded message ---------- > From: "Dieter Spaar" <spaar(a)mirider.augusta.de> > To: baseband-devel(a)lists.osmocom.org > Date: Thu, 01 Sep 2011 07:59:31 CEST > Subject: Re: 900MHz packet radio? > Hello Paul, > > On Thu, 1 Sep 2011 13:41:11 +0930, "Paul Gardner-Stephen" <paul(a)servalproject.org> wrote: >> >> So, as the open-source group with the most experience reprogramming >> baseband radios, what is the feasibility of creating a >> proof-of-concept using the types of phones you already work with to >> send and receive arbitrary data packets without reliance on a cell >> tower (even for time synchronisation)? > > It depends a lot on what you want to use on the lower layers > (e.g. Modulation). The TI Calypso based phones have a built-in > GMSK hardware modulator, so it is GMSK. Also the symbolrate is > fixed to the one used by GSM. I had assumed that the modulation would be fixed in this way, and it is not an issue for what I am wanting to do. In fact, it makes a lot of sense to keep the GSM modulation for simplicity. > Then there is the DSP which does the signal processing work. Its > again tied to the GSM standard (format of the burst and length). > It might be possible to put something else into the relativ small > RAM inside the DSP, but this could be a huge effort. This seems to me to be the hardest part of the whole process. When you say a huge effort, do you think it would be possible for someone to be able to get something working if they were able to work on it full-time for a few months? > Besides that you have to modify the hardware of the phone (remove > a filter) so that the phone can receive another phone. But this > is probably the smallest problem of all. Indeed, this is the smallest problem I think. In fact, if we use the part of the ISM915 band that is right next to the GSM band, then my understanding is the filter will only attenuate by a few db -- although I am happy to be corrected on this point. > Best regards, > Dieter > -- > Dieter Spaar, Germany spaar(a)mirider.augusta.de > > > > > ---------- Forwarded message ---------- > From: Scott Weisman <sweisman(a)pobox.com> > To: baseband-devel <baseband-devel(a)lists.osmocom.org> > Date: Thu, 1 Sep 2011 10:18:21 +0300 > Subject: Re: 900MHz packet radio? > I think you would be better taking your existing hardware, which must be somewhat custom to begin with (since it works over wifi) and use something like a HopeRF module (http://www.hoperf.com/) or similar. HopeRF has transceivers with power output up 100mW, data rates up to 256kbps, and a choice of 4 different bands (315, 433, 868, 915). This sounds like it would be a far easier choice to incorporate into your already-working system than hacking OsmocomBB-capable phones. > There is a lot of development from many different companies in this area and quite a bit of hacker activity as well. We are exploring that path simultaneously, and have a batch of the exactly the HopeRF modules that we will use, to demonstrate the range and utility of using the ISM band for long-range mesh telephony. But it is important also that we prove that it can be done using the baseband radio in a phone. We all know that it can if we have the freedom to design the baseband radio from scratch, but that it can also be done it is also important that I show that for handsets where the baseband radio can be reprogrammed without changing the hardware. It all boils down to being able to deflect any straw arguments that might be raised against the feasibility of long-range mesh telephony using baseband radio. Paul. > Scott > > On Thu, Sep 1, 2011 at 7:11 AM, Paul Gardner-Stephen <paul(a)servalproject.org> wrote: >> >> Greetings all, >> >> At the Serval Project we have created a mobile mesh telephony system >> that currently works over wifi. >> >> >From the outset, we have wanted to get it working on the ISM915 and/or >> ISM868 bands that are located adjacent to the GSM 850/900 frequency >> allocations. >> >> My initial investigations and enquiries indicate that this should be >> possible by creative programming of the baseband processor in many >> models of phones. The trick, as I suspect you well know, is the >> difficulty in getting the information and tools required to reprogram >> these radios. >> >> I am now in a position to potentially fund further work on this. >> >> So, as the open-source group with the most experience reprogramming >> baseband radios, what is the feasibility of creating a >> proof-of-concept using the types of phones you already work with to >> send and receive arbitrary data packets without reliance on a cell >> tower (even for time synchronisation)? >> >> I know there are a lot of constraints and problems, but I am most >> interested in creative solutions that can get us to a working >> prototype, however crude, that can be used to demonstrate the >> feasibility of what I am proposing. >> >> If this discussion is off-topic here, I am happy to hold the >> conversation at the serval-project-developers google group, but I am >> equally comfortable with it continuing here. >> >> Thanks in advance, >> Paul Gardner-Stephen. >> Shuttleworth Telecommunications Fellow at Flinders University. >> > > > _______________________________________________ > baseband-devel mailing list > baseband-devel(a)lists.osmocom.org > https://lists.osmocom.org/mailman/listinfo/baseband-devel > >

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Re: 900MHz packet radio?
by Dieter Spaar 01 Sep '11

01 Sep '11

Hello Paul, On Thu, 1 Sep 2011 13:41:11 +0930, "Paul Gardner-Stephen" <paul(a)servalproject.org> wrote: > > So, as the open-source group with the most experience reprogramming > baseband radios, what is the feasibility of creating a > proof-of-concept using the types of phones you already work with to > send and receive arbitrary data packets without reliance on a cell > tower (even for time synchronisation)? It depends a lot on what you want to use on the lower layers (e.g. Modulation). The TI Calypso based phones have a built-in GMSK hardware modulator, so it is GMSK. Also the symbolrate is fixed to the one used by GSM. Then there is the DSP which does the signal processing work. Its again tied to the GSM standard (format of the burst and length). It might be possible to put something else into the relativ small RAM inside the DSP, but this could be a huge effort. Besides that you have to modify the hardware of the phone (remove a filter) so that the phone can receive another phone. But this is probably the smallest problem of all. Best regards, Dieter -- Dieter Spaar, Germany spaar(a)mirider.augusta.de

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Re: GRPS decode - trying to download firmware to C123
by smithmr103＠gmail.com 31 Aug '11

31 Aug '11

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GRPS decode - trying to download firmware to C123
by smithmr103＠gmail.com 31 Aug '11

31 Aug '11

Hello list, I'm newbee so excuse me for my very basic question. I follow all the instructions on srlabs.de/gprs given by Karsten I have a C123 and a USB / jack 2.5mm - pl2303 based :( All steps are fine until I try to programm the compal ram ;) ./host/osmocon/osmocon -m c123xor -p /dev/ttyUSB0 ./target/firmware/board/compal_e88/layer1.compalram.bin I get : ... PROMPT1... ... PROMPT2... handle_write(): xxxx bytes (xxxx/yyyy) ... ... handle_write(): xxxx bytes (xxxx/yyyy) Received 1 byte : xx Received 1 bytes : yy ... ... Finally I received e.r.r.o.r (byte by byte) NOT ACK RECEIVED... I can also get (not with the same firmware...) : ... PROMPT1... ... PROMPT2... handle_write(): xxxx bytes (xxxx/yyyy) ... ... handle_write(): finished and then... nothing... I'm going to test the cable, as Philipp has told to Pavel. I also bought a RS232 / Jack unlocking Motorola (C123) cable and I own a BlackBox FTDI based USB/RS232 cable... So I'll test it as soon as I receive the cable. Do you think is a matter of cable, who is supposed to be osmocom compatible, or a phone issue or even the USB port... ? Thank you very much for your help and excuse me again with this kind of 'stupid' question about cable. I read almost all the subjects, I did a lot of experimentations in a lot of git branch (master, testing, burst_ind - of course not working with PL2303 ... + d1cb8ea9b784c7acbafbb2fdcedbdf4655c2f6f5 not working too) I think it must work at least in the master branch... Smith

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Suggestion from the PR department
by Ingo Albrecht 31 Aug '11

31 Aug '11

Hey guys I've been noticing the neverending stream of serial cable issues popping up here. To end this, I have a suggestion: how about checking the cable type via sysfs? Greets prom

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GPRS decode:FTDI cable
by list_mailing＠libero.it 30 Aug '11

30 Aug '11

Please, can someone suggest a model for the FTDI cable? I have found different types on internet, but I'd like to buy one it will be definitively ok. Thanks in advance.

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R: Re: GPRS Vs EDGE - Trying to decode my own sessions
by Luca Bongiorni 29 Aug '11

29 Aug '11

Hi all, just to explain what i mean, i've attached a sample and the log from layer23. http://pastebin.com/pepx0tdv As you can see from the log i got the immediate-assign. and the i can see the slots. The only thing that i could be strange is the signal strength that sometimes is good and sometimes reaches -100 dBm. Here is the gprsdecode's output: http://pastebin.com/p7XrtKAt Obviously i tried other ARFCNs of all operators (with different c118/c123, FTDI cable) and i got always the same behaviour. Have you some hints to suggest? Tomorrow i will try with some DP-L10 and pubblish the relative results. P.S: As i already stated, Nohl's samples are well decoded and showed into wireshark. Regards, Luca > Hi Harald, > > Actually i could use some old phones that supports only GPRS (e.g. t68i, t39m, etc..), but these phones are not enough useful and i will explain why: > > - i would like to use a phone that has field-test engineering; > - i would like to set the phone to camp only in a fixed ARFCN. > > I was also trying a Pirelli DP-L10, but unfortunately i can only fix the band and not the arfcn. > > > Btw... after a while i finally found how to force my Blackberry to work on GPRS on a fixed arfcn: > > - Select an arfcn; > - Lock to this cell; [ http://tinyurl.com/3dcc6vm ] > - Disable Uplink 8-PSK; [ http://tinyurl.com/3dxp85d ] > > Finally the phone is ready to start the tests. [ http://tinyurl.com/3rhldrn ] > > > As you can see, that engineering field-test is very useful because is showing which Coding Scheme and TS are used. > > > Unfortunately at this point... even if i tried a lot of times, i could see imm-ass, the TS, but when i'm trying to decode the dumps... nothing is decoded and i cannot even decode third-party sessions that obviously i could find on the same arfcn that i'm using. > > So, at this state of art, I could decode only samples released from Nohl. > Someone else is having same problems? > > > Regards, > > Luca >

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OT: Chinese C118 supply?
by Harald Welte 29 Aug '11

29 Aug '11

Hi all, at the CCC Camp two weeks ago, a Chinese guy approached me, stating that there he has contacts to a considerable supply of very inexpensive C1xx family phones in China. Unfortunately we didn't exchange contact details, so I'm trying this route. If you are the person that has talked to me about this topic, pleaes contact me by private e-mail. I would love to use this opportunity to provide inexpensive C1xx phones to the larger OsmocomBB user community. Thanks in advance, Harald -- - Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/ ============================================================================ "Privacy in residential applications is a desirable marketing option." (ETSI EN 300 175-7 Ch. A6)

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GPRS Vs EDGE - Trying to decode my own sessions
by Luca Bongiorni 28 Aug '11

28 Aug '11

Hi all, i'm testing gprsdecode with osmocomBB and using the samples provided from Nohl works well. Using a Blackberry 8300 and my Wind's sim, i tried to dump some my internet sessions. Unfortunately even if i'm locking the MS to a fixed ARFCN, it is "upgrading" from GRPS to EDGE very quickly and i cannot dump an entire session and then decode it on gprsdecode. The only datas i could decode and view on wireshark are few "malformed packets". As i suppose the problem is that i'm not able to fix the MS to work only on gprs. Which phone did Luca use to make his tests? (just a simple one that was not EDGE capable? ) Which was the successful-rate of (third-party) decoded sessions? I'm asking it, because i'm not even able to "see" other's phones sessions... ok, could be possible that everyone else is using only EDGE... but seems strange. Have you some hints for that? Thank you for attention. Regards, Luca

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