OsmoPCU » History » Version 4
ipse, 02/19/2016 10:48 PM
Transitioning [wiki:osmo-bts] to [wiki:OsmoBTS]
1 | 3 | laforge | [[PageOutline]] |
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2 | 1 | laforge | = osmo-pcu = |
3 | |||
4 | 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 |
5 | Um (radio) interface on the MS-facing side, as well as the Gb Interface (NS,BSSGP) on the SGSN-facing side. |
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6 | 1 | laforge | |
7 | 3 | laforge | osmo-pcu is the Osmocom implementation of this PCU functionality. |
8 | |||
9 | 4 | ipse | It implements a custom L1 interface that can be used with [wiki:OsmoBTS] (specifically its |
10 | 1 | laforge | [http://www.sysmocom.de/products/sysmobts sysmoBTS] back-end), and also with |
11 | 3 | laforge | an unofficial version of OpenBTS that is being created by Fairwaves. |
12 | 1 | laforge | |
13 | 3 | laforge | Towards the SGSN, the BSSGP and NS protocols are implemented over UDP/IP, sometimes called "NS over IP". |
14 | It has been tested with [wiki:OsmoSGSN] as well as an Ericsson SGSN so far. |
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15 | 1 | laforge | |
16 | 3 | laforge | osmo-pcu is not fully stable yet, but already performing useful service for a number of users. |
17 | 1 | laforge | |
18 | == Source Code == |
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19 | |||
20 | The source code is available from git://git.osmocom.org/osmo-pcu.git |
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21 | |||
22 | You can browse it online via http://cgit.osmocom.org/cgit/osmo-pcu/ |
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23 | |||
24 | 4 | ipse | The branch to be used with [wiki:OsmoBTS] and sysmoBTS is the 'jolly_merge' branch. |
25 | 3 | laforge | |
26 | 1 | laforge | == Mailing List == |
27 | |||
28 | There is a mailing list for (development) discussion regarding the PCU: osmocom-pcu@lists.osmocom.org. |
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29 | You can subscribe to it (or manage your subscription) at http://lists.osmocom.org/cgi-bin/mailman/listinfo/osmocom-pcu |
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30 | 3 | laforge | |
31 | == Status == |
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32 | |||
33 | === Supported === |
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34 | * GPRS CS1 to CS4 |
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35 | * single-slot and multi-slot operation on downlink |
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36 | * only single-slot operation on uplink |
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37 | |||
38 | === Shortcomings / Limitations / Restrictions === |
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39 | |||
40 | * Pure GPRS PCU, no EGPRS (EDGE) functionality |
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41 | * Timeslots have to be assigned dedicated as a PDCH, no dynamic PDCH/TCH switching |
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42 | * No support for hand-over of any sort yet |
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43 | * No support of processing measurement reports |
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44 | * No timing advance loop, i.e. maximum cell radius 2-3 km |
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45 | * No dynamic link adaption for different coding schemes |
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46 | * No resource-dependent flow control |