Osmocom Base Transceiver Station (BTS)
https://osmocom.org/projects/osmobts
00b4e064ff
The BTS layer needs to inform the handover code when an access burst has been received. In turn the handover layer will ask the bts to modify the channel, it will schedule the physical information inform the BSC with the HANDOVER DETECTION and waits for the BTS layer to inform it about the first received frame to stop a timer. |
||
|---|---|---|
| contrib | ||
| doc/examples | ||
| include | ||
| src | ||
| tests | ||
| .gitignore | ||
| COPYING | ||
| Makefile.am | ||
| README | ||
| configure.ac | ||
| git-version-gen | ||
README
Repository for new the Osmocom BTS implementation. This code implementes the Layer 2 and higher of a more or less conventional GSM BTS (Base Transceiver Station) - however, using an Abis/IP interface, rather than the old-fashioned E1/T1. Specificallt, this includes * BTS-Side implementation of TS 08.58 (RSL) and TS 12.21 (OML) * BTS-Side implementation of LAPDm (using libosmocore/libosmogsm) * A somewhat separated interface between those higher layer parts and the Layer1 interface. Right now, only one hardware and Layer1 are supported: The sysmocom sysmoBTS. There is some experimental and way incomplete code to use a couple of OsmocomBB phones and run them in the BTS. However, the required code for the Calypso DSP code have not been written yet. This would still require a lot of work. Some additional work is being done in using some parts of the OpenBTS L1FEC and glue it against omso-bts. However, this is also still in an early, experimental stage. == Known Limitations == As of June 3, 2012, the following known limitations exist in this implementation: === Common Core === * No Extended BCCH support * System Information limited to 1,2,2bis,2ter,2quater,3,4,5,6,9,13 * No RATSCCH in AMR * No OML (TS 12.21) alarms yet (temperature, ...) * Only single-TRX BTS at this point * Will reject TS 12.21 STARTING TIME in SET BTS ATTR / SET CHAN ATTR * No support for frequency hopping * No reporting of interference levels as part of TS 08.58 RF RES IND * No error reporting in case PAGING COMMAND fails due to queue overflow * No hand-over support (planned) * No use of TS 08.58 BS Power and MS Power parameters * No support of TS 08.58 MultiRate Control * No support of TS 08.58 Supported Codec Types * No support of Bter frame / ENHANCED MEASUREMENT REPORT === osmo-bts-sysmo === * No CSD / ECSD support (not planned) * No GPRS/EDGE support (planned) * GSM-R frequency band supported, but no NCH/ASCI/SoLSA * All timeslots on one TRX have to use same training sequence (TSC) * No multi-TRX support yet, though hardware+L1 support stacking * Makes no use of 12.21 Intave Parameters and Interference Level Boundaries * Makes no use of TS 12.21 T3105 * Doesn't yet include MAC address in Abis/IP Identity message * MphConfig.CNF can be returned to the wrong callback. E.g. with Tx Power and ciphering. The dispatch should take a look at the hLayer3.