OpenBSC

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4 participants
4156 discussions

by Max

Hi. I'm troubleshooting peculiar use case with packet access and osmo-bts-trx. There are 2 options for ME to acknowledge reception of control packet to PCU according to 3GPP TS 44.060 § 11.2.2: 1) Packet Control Acknowledgement message 2) 4 identical access bursts The latter can be both 8-bit RACH and 11-bit RACH (not supported by osmo-bts-trx yet). The choice of response format is defined by OpenBSC in SI: 1) is default, 2) can be activated with "gprs control-ack-type-rach" option. The problem is that I don't understand how 2) will be handled by OsmoTRX? Shall I expect 4 consecutive RACH messages via rx_rach_fn() in scheduler_trx.c in osmo-bts-trx? Shall it be some other message/function? Will it be ignored/dropped altogether by OsmoTRX? -- Max Suraev <msuraev(a)sysmocom.de> http://www.sysmocom.de/ ======================================================================= * sysmocom - systems for mobile communications GmbH * Alt-Moabit 93 * 10559 Berlin, Germany * Sitz / Registered office: Berlin, HRB 134158 B * Geschaeftsfuehrer / Managing Director: Harald Welte

8 years, 1 month

osmo-trx: GSM signal generator

by Tom Tsou

Hi All, I wrote a GSM signal generator application based on osmo-trx. The new osmo-siggen allows random GSM or EDGE burst generation without using special configurations of osmo-trx or the socket control interface. Frame trigger output through GPIO is also available. I use the application for testing modulation parameters and other PHY level testing. Hopefully it's useful to other developers beyond myself. $ ./osmo-siggen -h Options: -h, --help This text -a, --args UHD device args -l --log Logging level ('err', 'warn', 'notice', 'info', 'debug') -b, --burst Burst type ('normal', 'access', 'freq', 'sync', 'edge') -r, --ref Frequency reference ('internal', 'external', 'gps') -f, --freq Tx RF frequency -g, --gain Tx RF gain -s, --sps Tx samples-per-symbol (only 4 supported) -m, --mod GSMK modulator type ('laurent4', 'laurent2', 'laurent1', 'nco') -p, --ampl Tx amplitude (0.0 - 1.0) -o, --offset Baseband frequency offset -t, --tsc Normal and EDGE burst training sequence (0-7) -S, --swap Swap channels Currently osmo-siggen is located in the below branch. I've tested solely with B210. C++14 availability is also required for now. git://git.osmocom.org/osmo-trx ttsou/siggen -TT

8 years, 1 month

osmo-trx: Generating frame sync output on GPIO?

by Harald Welte

Hi all, I was wondering if it is possible to generate a TDMA frame sync output on a GPIO line of a USRP device (and/or any other SDR supported by osmo-trx). This way it would be much easier to do e.g. BER testing by using a pure waveform/pattern generator for the "MS side". Such devices (Like an E4433B) can only generate the uplink bursts with pseudo-random sequence, but they don't have any receiver, so they're not able to receive the downlink from the BTS in order to lock on the TDMA frame and transmit the uplink in sync to that. There are of course specialized devices (CMU-300, ...) or hardware options that add such receivers for synchronization on the signal generators, equipment side, but why go there if there would be an easy way to generate some kind of a frame sync output. I would appreciate to know even if there's a way to introduce such "synchronous GPIO toggles" or the like in the command stream to UHD devices. If that existed, it should be rather simple to insert those whenever a new burst for TS0 is sent. A rather computationally (and bandwidth) expensive other option might be to use the second RF output to generate such a signal, but I was hoping not having to abuse the 2nd channel for that ;) Regards, 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)

8 years, 1 month

Accelerate3g5 Problem in cellphone attach procedure

by Lin HUANG

Hello, We met a problem during the cellphone trying to attach to the network. The modules we ran are: Nano femtocell <- LAN -> osmo-hnbgw <--> osmo-msc <--> osmo-hlr. The cellphone with sysmcom USIM searched the network 90170 and then tried to register in it. The authentication was passed but the connection was released. The cellphone automatically repeated the attach again and again, but always failed. In the output of HLR, it seems the authentication is OK: ---------------------- 20170606183004032 DAUC <0003> db_auc.c:222 901700000014922: Generated 5 vectors 20170606183004032 DAUC <0003> db_auc.c:227 901700000014922: Updating SQN=1728 in DB ... 20170606183005665 DMAIN <0000> luop.c:148 LU OP state change: NULL -> LU RECEIVED 20170606183005665 DMAIN <0000> luop.c:148 LU OP state change: LU RECEIVED -> ISD SENT ---------------------- But in the output of MSC: ---------------------- 20170606183005665 DMM <0002> gsm_04_08.c:3798 <- SECURITY MODE COMPLETE IMSI:901700000014922 ... 20170606183005666 DMM <0002> gsm_04_08.c:201 -> MSISDN:333 LOCATION UPDATE ACCEPT ... 20170606183005666 DMSC <000a> msc_ifaces.c:44 msc_tx 17 bytes to MSISDN:333 via RAN_UTRAN_IU 20170606183005666 DRANAP <001a> iu.c:391 Transmitting L3 Message as RANAP DT (SUA link 0xcacde0 conn_id 0) 20170606183005666 DSUA <001b> sua.c:506 Received SCCP User Primitive (N-DATArequest) 20170606183005666 DSUA <001b> sua.c:160 sua_link_send(01 00 08 08 00 00 00 40 00 06 00 08 00 00 00 00 01 05 00 08 00 00 03 e8 01 0b 00 26 00 14 00 1e 00 00 02 00 10 40 12 11 05 02 09 f1 89 28 b6 17 08 99 10 07 00 00 10 94 22 00 3b 40 01 00 00 00 ) 20170606183005666 DVLR <001d> vlr_lu_fsm.c:321 lu_compl_vlr_fsm(901700000014922)[0xcab580]{LU_COMPL_VLR_S_WAIT_SUB_PRES}: state_chg to LU_COMPL_VLR_S_DONE 20170606183005666 DVLR <001d> vlr_lu_fsm.c:355 vlr_lu_fsm(901700000014922)[0xcd5250]{VLR_ULA_S_WAIT_LU_COMPL}: Received Event VLR_ULA_E_LU_COMPL_SUCCESS 20170606183005666 DVLR <001d> vlr_lu_fsm.c:733 lu_compl_vlr_fsm(901700000014922)[0xcab580]{LU_COMPL_VLR_S_DONE}: Terminating (cause = OSMO_FSM_TERM_PARENT) 20170606183005666 DVLR <001d> vlr_lu_fsm.c:733 lu_compl_vlr_fsm(901700000014922)[0xcab580]{LU_COMPL_VLR_S_DONE}: Removing from parent vlr_lu_fsm(901700000014922)[0xcd5250] 20170606183005666 DVLR <001d> vlr_lu_fsm.c:733 lu_compl_vlr_fsm(901700000014922)[0xcab580]{LU_COMPL_VLR_S_DONE}: Freeing instance 20170606183005666 DVLR <001d> fsm.c:275 lu_compl_vlr_fsm(901700000014922)[0xcab580]{LU_COMPL_VLR_S_DONE}: Deallocated 20170606183005666 DVLR <001d> vlr_lu_fsm.c:700 vlr_lu_fsm(901700000014922)[0xcd5250]{VLR_ULA_S_WAIT_LU_COMPL}: state_chg to VLR_ULA_S_DONE 20170606183005666 DMM <0002> vlr_lu_fsm.c:692 Subscr_Conn(901700000014922)[0xcd22f0]{SUBSCR_CONN_S_NEW}: Received Event SUBSCR_CONN_E_ACCEPTED 20170606183005666 DMM <0002> subscr_conn.c:77 Subscr_Conn(901700000014922)[0xcd22f0]{SUBSCR_CONN_S_NEW}: SUBSCR_CONN_FROM_LU 20170606183005666 DMM <0002> subscr_conn.c:84 Subscr_Conn(901700000014922)[0xcd22f0]{SUBSCR_CONN_S_NEW}: state_chg to SUBSCR_CONN_S_ACCEPTED 20170606183005668 DMM <0002> subscr_conn.c:132 Subscr_Conn(901700000014922)[0xcd22f0]{SUBSCR_CONN_S_ACCEPTED}: Received Event SUBSCR_CONN_E_BUMP 20170606183005668 DMM <0002> subscr_conn.c:168 Subscr_Conn(901700000014922)[0xcd22f0]{SUBSCR_CONN_S_ACCEPTED}: bump: releasing conn 20170606183005668 DMM <0002> subscr_conn.c:169 Subscr_Conn(901700000014922)[0xcd22f0]{SUBSCR_CONN_S_ACCEPTED}: state_chg to SUBSCR_CONN_S_RELEASED 20170606183005668 DMM <0002> subscr_conn.c:255 Subscr_Conn(901700000014922)[0xcd22f0]{SUBSCR_CONN_S_RELEASED}: Terminating (cause = OSMO_FSM_TERM_REGULAR) ---------------------- Why is there a 'Received Event SUBSCR_CONN_E_BUMP'? Regards Lin

8 years, 1 month

ericsson rbs2308

by Rajitha peiris

hello everyone ...... anyone doingwith rbs2308 ? i am doing with dhai and E1 interface but it doesn't come to operational mode ....if anyone got any output from rbs 2308 pls let me thanks rajitha

8 years, 1 month

images

by Neels Hofmeyr

People keep posting images to this list. I saw that mailman allows to remove image attachments by file suffix and/or by mime type. I suggest we put jpg, png, bmp on the list of attachments to remove. AFAICT there was zero need for a legitimate image post, and if we'd want to we can always create a wiki page or redmine ticket and attach the image there. It would be nicer to bounce messages with such attachments completely, but dropping the attachments is the next best thing. Opinions? I don't have access to the list admin, so (if we agree) someone else would need to effect this / give me the pw: mailman admin / "MIME-/HTML-Filter" / tick 'yes' on top and add image suffixes to the reject list ~N

8 years, 1 month

ipaccess 1800/1900 model

by Albert Paijmans

Hello, In the Netherlands the free gsm channel for private gsm networks is; 1875 - 1879,9 MHz 200 mW e.r.p. 200 kHz 875 - 1879,8 MHz 50 mW/MHz e.r.p. ≤4,5 MHz But I am a little bit confused as to how to set up an ipacces nanobts with those frequencies In OsmoBTS configuration file find bts 0 and set band to GSM1800 Also set frequencies to right value arfcn The example says ( https://osmocom.org/projects/openbsc/wiki/Multi-BTS_with_handover) trx 0 rf_locked 0 arfcn 74 ... trx 1 rf_locked 0 arfcn 84 --------------- I am not sure what to put at arfcn as the correct frequency with the mentioned frequency.. A second question, the nanoBTS comes in 1800 for GSM1800, and GSM1900 variant thereof (almost identical hardware) Well I can get 2 of the 1900 version very cheap from the USA but setting the configuration file bts 0 band GSM1800 won´t change the frequeny of the 1900 model to 1800MHz? Or can I only use the 1900 version in the free 1900MHz DECT frequency range? I have attached the official document of the Dutch regulatory body with the allowed frequencies, see page 28 for DECT frequencies in 1900 band and page 29 for picocell frequencies in the 1800 band. To me it seems both bands 1800 and 1900 are allowed, 1800Mhz is the official private gsm but for testing purposes using a 1900 model on the DECT band should be ok to. If the nanobts 1900 US model could also operate on the 1800 band that would be even better. Thanks, Albert

8 years, 1 month

osmo-gsm-manuals DRAFT

by Neels Hofmeyr

In our osmo-gsm-manuals, there are various code listings that one would like to copy-paste from the PDF. That would theoretically work, but practically, the 'DRAFT' watermark in the backdrop confuses the text marking, hence making copy-pasting some text from the manuals very very cumbersome. Though I'm not that sure why we need a 'DRAFT' watermark in an open source manual (it's implicitly a draft), I am fine with having such a marking. But I would like the marking to be less obtrusive. We could experiment with putting a bitmap image in the backdrop instead of text, or even better IMHO would be to put it in the page header next to the version. We could also add a generic "DRAFT" disclaimer near the beginning of each document. (Same goes for the sysmocom internal manuals, for which it isn't so easy to get the asciidoc source to paste from.) Any opinions on this? ~N

8 years, 1 month

libosmo-sccp: Build breakage on --disable-static

by Holger Freyther

Hi, I just looked into a build breakage when --disable-static is passed. The first failure is because of: libosmo_sigtran_la_LDFLAGS = -version-info $(LIBVERSION) \ -no-undefined \ -export-symbols-regex '^osmo_' The testcases use xua_* sua_ symbols but they are not exported. Shall we export them or shall we forbid --disable-static on libosmo-sccp? The second part is that I had preferred the sccp library to be static only to avoid having to do proper ABI checking/versioning. If we fix the above, maybe we have to fix this part too? holger

8 years, 1 month

Initial Suggestion | Merging osmo-sim-auth and PySIM and update on MNCC with OsmocomBB

by Gerard Lawrence Pinto

Greetings, Congrats on OsmoCon 2017! I have been working with OsmocomBB, osmo-sim-auth, mncc-python projects in Osmocom. I would like to contribute some code snippets with your acceptance. To begin with I have committed: I) MNCC with OsmocomBB - *https://github.com/GerardPinto/call-control-mncc-sap <https://github.com/GerardPinto/call-control-mncc-sap>* (Has both implementations in Python and C + Tested voice with gsm-fr with gsm audio file - works great). - Some of which can be committed to mncc-python? (In order to support MNCC with OsmocomBB too) Although, Harald told me it was built for OpenNITB - I'm not sure, the relevance of this contribution to this repo? Reason: 1. Solves some mailing list questions: Some questions on mailing list are pertaining sending voice from PC to phone and receive. 2. Useful for test cases: In the future, if 'gsm-efr' codec is implemented, we can use these snippets and send audio with gsm-efr sample, instead of connecting to LCR (Am I correct?) *Issues faced*: File: l23api.c | function: l1ctl_rx_traffic_req() 264 bits (33 bytes) of voice codec are interleaved into 456 bits. The DAC, ciphering/deciphering , RF etc. work on 114 bits at a time so, 114 x 4 = 456. So Layer23 sends 4 - 114 bits into the queue to Layer1 in function => l1ctl_rx_traffic_req *Code*: num = l1a_txq_msgb_count(&l1s.tx_queue[L1S_CHAN_TRAFFIC]) if num > 4 dropping traffic frame. (114 x 4) The code above indicates if queue has any (114 x 4) bits drop the incoming voice request. So I faced the issue of voice packets getting dropped, but that was just twice/thrice and then it did not give me any trouble (I'm not sure how it got fixed), I could hear *clear* voice gsm-fr on the called party cell phone. *My Question is*: If I happened to send voice packets 33 bytes really fast. There should be some kind of buffer rather than a check (Code) and drop frame? - OR this case can never happen? My apologies, if my understanding is incorrect, I just tried to reverse engg. from code and GSM codec available online! II) osmo-sim-auth with added other SIM related API's (still needs code clean up, SIM response check, code re-usable, README.md etc,) * https://github.com/GerardPinto/osmo-sim-auth <https://github.com/GerardPinto/osmo-sim-auth> * - I did check out PySIM (I think I can add some code to the existing repository, with your permission). Could you please let me know if my osmo-sim-auth repo? If it is correct to combine with PySIM, with the changes done below? Files modified: 1. SIM.py - Added more API's. 2. osmo-sim-auth.py - Options parser. Thanks, Gerard.

8 years, 1 month

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