OpenBSC July 2016

openbsc@lists.osmocom.org

19 participants
42 discussions

Is there a maximum separation in Mhz for ARFCNs on one BTS?
by Keith Whyte 01 Jul '16

01 Jul '16

Hi all, Would somebody who is familiar with the relevant part of the GSM spec be able to comment? I'm wondering if there's any issue in GSM running a dual TRX BTS with two ARFCNs on opposite ends of the band? For example, in GSM850, this would mean the downlinks could be on 869.2 and 893.8 Mhz so the phone could have to tune across a wider range between the SDCCH and TCH for example. Thanks!

2 1

osmo-nitb/osmo-bts-trx: Logging traffic on A-bis interface
by Sebastian Stumpf 01 Jul '16

01 Jul '16

Hi all, I wanted to check if the bts - bsc communication works properly with my configuration. For example, if my osmo-nitb does send the system information messages to the bts. I tried the vty logging interface of osmo-bts and logged some messages, but they were not the messages I expected. I configured the groups rsl, oml, rll, rr and abis to "notice", all to "everything" and everything else to "error" and got following log output (lots of these and nothing else): ... <0006> scheduler.c:405 PH-RTS.ind: chan=CCCH chan_nr=0x90 link_id=0x00 fn=993588 ts=0 trx=0 <0006> scheduler.c:341 PH-DATA.req: chan_nr=0x90 link_id=0x00 fn=993588 ts=0 trx=0 ... PH-RTS.ind and PH-DATA.req seem to come from layer1 SAP, the osmo-trx and have probably nothing to do with the SI messages. Is traffic on abis generally not logged or is my log config faulty? I ended up configuring the gsmtap interface for osmo-bts and could so see the uplink/downlink in wireshark and could see that the SI information is properly sent. But gsmtap only works for the air interface. What is the best way for logging/sniffing the communication on the A-bis interface? With kind regards, Sebastian Stumpf

3 2

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

OpenBSC July 2016