17954da56c
Since there can be multiple PDCH channels configured on different timeslots, different TRXes, and BTSes, the PTCCH/U handling code in OsmoPCU needs to know the exact origin of a given RACH.ind. Otherwise, it is not known which subscriber originated a given PTCCH/U indication, and hence it is impossible to send PTCCH/D Timing Advance notification properly. Fortunately, we can extend the RACH.ind message without even bumping the protocol version, because every single PDU has a fixed size defined by the largest message - INFO.ind. In case if the actual message payload is smaller, the rest is filled with a constant padding byte (0x00). Older versions of OsmoPCU will consider the new fields as padding, while the messages from older OsmoBTS versions will always have both fields set to 0x00. Since C0/TS0 cannot be configured to PDCH, this can be easily detected on the other end. Change-Id: If209001885ffb14b64a8e808df3700d85a4b2ef9 Related: OS#1545 |
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osmoappdesc.py |
README.md
osmo-pcu - Osmocom Packet Control Unit
This repository contains a C/C++-language implementation of a GPRS Packet Control Unit, as specified by ETSI/3GPP. It is part of the Osmocom Open Source Mobile Communications project.
The Packet Control Unit is terminating the Layer 2 (RLC/MAC) of the GPRS radio interface and adapting it to the Gb Interface (BSSGP+NS Protocol) towards the SGSN.
The PCU interfaces with the physical layer of the radio interface. OsmoPCU is typically used co-located with the BTS, specifically OsmoBTS. For legacy BTSs that run proprietary sotware without an interface to OsmoPCU, you may also co-locate it with the BSC, specifically OsmoBSC
Homepage
The official homepage of the project is https://osmocom.org/projects/osmopcu/wiki/OsmoPCU
GIT Repository
You can clone from the official osmo-pcu.git repository using
git clone git://git.osmocom.org/osmo-pcu.git
There is a cgit interface at http://git.osmocom.org/osmo-pcu/
Documentation
We provide a user manual as well as a vty reference manual
Please note that a lot of the PCU configuration actually happens inside the BSC, which passes this configuration via A-bis OML to the BTS, which then in turn passes it via the PCU socket into OsmoPCU.
Mailing List
Discussions related to osmo-pcu are happening on the osmocom-net-gprs@lists.osmocom.org mailing list, please see https://lists.osmocom.org/mailman/listinfo/osmocom-net-gprs for subscription options and the list archive.
Please observe the Osmocom Mailing List Rules when posting.
Contributing
Our coding standards are described at https://osmocom.org/projects/cellular-infrastructure/wiki/Coding_standards
We us a gerrit based patch submission/review process for managing contributions. Please see https://osmocom.org/projects/cellular-infrastructure/wiki/Gerrit for more details
The current patch queue for osmo-pcu can be seen at https://gerrit.osmocom.org/#/q/project:osmo-pcu+status:open
Current limitations
- No PFC support
- No fixed allocation support (was removed from 3GPP Rel >= 5 anyway)
- No extended dynamic allocation support
- No unacknowledged mode operation
- Only single slot assignment on uplink direction
- No half-duplex class support (only semi-duplex)
- No TA loop
- No power loop