In situations where the PCU is co-located to the BSC, the IMMEDIATE ASSIGNMENT for downlink TBFs must be sent via RSL and the BSC also must instruct the BTS to transmit the IMMEDIATE ASSIGNMENT via PCH instead of AGCH. Eventually the BSC must sent a confirmation message (follow-up patch) where the TLLI is used as an identifer. This new method will eventually replace the previous method that uses the MAC block as an identifier. To remain compatible with older versions of osmo-bsc, we will keep the old method until osmo-bts is migrated as well. This patch also requires new features to be added to the PCU socket interface the version number of the protocol is incremented from 0x0a to 0x0b. Version 0x0a will remain compatible and use the old method, while version 0x0b will use the new method introduced with this patch. Change-Id: I2a78651593323e8b9627c39918d949a33497b70f Related: OS#5198
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
The official homepage of the project is https://osmocom.org/projects/osmopcu/wiki/OsmoPCU
You can clone from the official osmo-pcu.git repository using
git clone https://gitea.osmocom.org/cellular-infrastructure/osmo-pcu
There is a web interface at https://gitea.osmocom.org/cellular-infrastructure/osmo-pcu
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.
Discussions related to osmo-pcu are happening on the email@example.com 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.
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
- 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
- Multi-BTS support not tested