OsmoPCU » History » Version 16
Anonymous, 02/19/2016 10:48 PM
| 1 | 16 | laforge | {{>toc}} |
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| 2 | 1 | laforge | |
| 3 | 16 | laforge | h1. osmo-pcu |
| 4 | |||
| 5 | |||
| 6 | 3 | laforge | A PCU (Packet Control Unit) is one of the two GPRS elements in the BSS. It implements the RLC and MAC layers of the GPRS |
| 7 | 1 | laforge | Um (radio) interface on the MS-facing side, as well as the Gb Interface (NS,BSSGP) on the SGSN-facing side. |
| 8 | |||
| 9 | 3 | laforge | osmo-pcu is the Osmocom implementation of this PCU functionality. |
| 10 | 1 | laforge | |
| 11 | 16 | laforge | It implements a custom L1 interface that can be used with [[OsmoBTS]] (specifically its |
| 12 | "sysmoBTS":http://www.sysmocom.de/products/sysmobts back-end), and also with |
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| 13 | [[OsmoTRX]]. |
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| 14 | 3 | laforge | |
| 15 | 1 | laforge | Towards the SGSN, the BSSGP and NS protocols are implemented over UDP/IP, sometimes called "NS over IP". |
| 16 | 16 | laforge | It has been tested with [[osmo-sgsn]] as well as an Ericsson SGSN so far. |
| 17 | 1 | laforge | |
| 18 | 13 | laforge | osmo-pcu is now considered stable and already performing useful service for a number of users, but as one |
| 19 | 14 | jerlbeck | of the more recent additions to the Osmocom family, there still is plenty of area for improvement. |
| 20 | 11 | laforge | |
| 21 | 1 | laforge | |
| 22 | 16 | laforge | h2. Source Code |
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| 24 | |||
| 25 | 1 | laforge | The source code is available from git://git.osmocom.org/osmo-pcu.git |
| 26 | |||
| 27 | You can browse it online via http://cgit.osmocom.org/cgit/osmo-pcu/ |
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| 31 | 16 | laforge | h2. Mailing List |
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| 33 | |||
| 34 | 1 | laforge | There is a mailing list for (development) discussion regarding the PCU: osmocom-net-gprs@lists.osmocom.org |
| 35 | You can subscribe to it (or manage your subscription) at http://lists.osmocom.org/cgi-bin/mailman/listinfo/osmocom-net-gprs |
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| 38 | 16 | laforge | h2. Status |
| 39 | |||
| 40 | Information about testing is available here: [[GPRS-testing]] |
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| 41 | |||
| 42 | |||
| 43 | h3. Supported |
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| 44 | |||
| 45 | * GPRS CS1 to CS4 with dynamic link/rate adaption |
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| 46 | 1 | laforge | * EDGE MCS1-MCS9 with dynamic link/rate adaption |
| 47 | 16 | laforge | * Single-slot and multi-slot operation on downlink |
| 48 | * Single-slot operation on uplink |
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| 49 | * Independent TFI/USF per PDCH in single-slot allocation mode |
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| 50 | * Automatic or fixed PDCH allocation algorithm selection |
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| 51 | * Delayed release of downlink TBF |
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| 52 | * Active queue management for downlink TBF (!CoDel) |
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| 53 | * Initial setting of timing advance based on RACH |
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| 54 | * BSSGP BVC flow control support |
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| 55 | 1 | laforge | |
| 56 | |||
| 57 | 16 | laforge | h3. Shortcomings / Limitations / Restrictions |
| 58 | 14 | jerlbeck | |
| 59 | 16 | laforge | |
| 60 | * No GPRS/EGPRS mixed mode (yet) |
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| 61 | * Timeslots have to be assigned dedicated as a PDCH, no dynamic PDCH/TCH switching |
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| 62 | * No support for hand-over of any sort yet |
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| 63 | * No support of processing measurement reports |
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| 64 | * No timing advance loop, i.e. radial movement is limited |
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| 65 | * No support for power control |
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| 66 | * No Packet Access Reject message on congestion, access is just ignored |
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| 67 | * No PCCCH support |
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| 68 | * Only "Dynamic allocation RLC data block transfer" is supported |
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| 69 | * No network controlled measurement/cell reselection order supported |
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| 70 | * No PTCCH support |
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| 71 | * No support for Packet Flow Contexts (PFC) |
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| 72 | * No support for MS or PFC flow control |
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| 73 | * No support for RLC unacknowledged mode operation |
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| 74 | * No support for MBMS |
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| 75 | |||
| 76 | |||
| 77 | h2. Authors / Credits |
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| 78 | |||
| 79 | 1 | laforge | |
| 80 | osmo-pcu was originally developed by Ivan Kluchnikov and Andreas Everberg. |
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| 81 | |||
| 82 | Today it is maintaned by Jacob Erlbeck at sysmocom. |
