58 lines
2.2 KiB
Plaintext
58 lines
2.2 KiB
Plaintext
= Repository for the Osmocom BTS implementation. =
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For most complete and accurate information, please refer to
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https://osmocom.org/projects/osmobts/wiki
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To submit patches, please refer to
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https://osmocom.org/projects/cellular-infrastructure/wiki/Gerrit
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(Note: github pull requests are rejected by a bot)
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== Summary ==
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This code implements Layer 2 and higher of a more or less conventional GSM BTS
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(Base Transceiver Station) - however, using an Abis/IP interface, rather than
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the old-fashioned E1/T1.
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Specifically, this includes
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* BTS-side implementation of TS 08.58 (RSL) and TS 12.21 (OML)
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* BTS-side implementation of LAPDm (using libosmocore/libosmogsm)
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* A somewhat separated interface between those higher layer parts and the
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Layer1 interface.
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Several kinds of BTS hardware are supported:
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* sysmocom sysmoBTS
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* Octasic octphy
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* Nutaq litecell 1.5
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* software-defined radio based osmo-bts-trx (e.g. B210)
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== Known Limitations ==
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As of August 20, 2015, the following known limitations exist in this
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implementation:
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=== Common Core ===
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* No Extended BCCH support
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* System Information limited to 1,2,2bis,2ter,2quater,3,4,5,6,9,13
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* No RATSCCH in AMR
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* No OML (TS 12.21) alarms yet (temperature, ...)
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* Only single-TRX BTS at this point
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* Will reject TS 12.21 STARTING TIME in SET BTS ATTR / SET CHAN ATTR
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* No support for frequency hopping
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* No reporting of interference levels as part of TS 08.58 RF RES IND
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* No error reporting in case PAGING COMMAND fails due to queue overflow
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* No use of TS 08.58 BS Power and MS Power parameters
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* No support of TS 08.58 MultiRate Control
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* No support of TS 08.58 Supported Codec Types
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* No support of Bter frame / ENHANCED MEASUREMENT REPORT
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=== osmo-bts-sysmo ===
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* No CSD / ECSD support (not planned)
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* GSM-R frequency band supported, but no NCH/ASCI/SoLSA
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* All timeslots on one TRX have to use same training sequence (TSC)
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* No multi-TRX support yet, though hardware+L1 support stacking
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* Makes no use of 12.21 Intave Parameters and Interference
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Level Boundaries
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* Doesn't yet include MAC address in Abis/IP Identity message
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* MphConfig.CNF can be returned to the wrong callback. E.g. with Tx Power
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and ciphering. The dispatch should take a look at the hLayer3.
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