OsmoPCU » History » Version 25
laforge, 05/11/2018 11:03 AM
1 | 1 | laforge | h1. osmo-pcu |
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2 | 16 | laforge | |
3 | 17 | laforge | {{>toc}} |
4 | 16 | laforge | |
5 | 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 |
6 | 1 | laforge | Um (radio) interface on the MS-facing side, as well as the Gb Interface (NS,BSSGP) on the SGSN-facing side. |
7 | |||
8 | 3 | laforge | osmo-pcu is the Osmocom implementation of this PCU functionality. |
9 | 1 | laforge | |
10 | 18 | laforge | It implements a custom L1 interface that can be used with [[OsmoBTS:]] (specifically its |
11 | 16 | laforge | "sysmoBTS":http://www.sysmocom.de/products/sysmobts back-end), and also with |
12 | 18 | laforge | [[OsmoTRX:]]. |
13 | 3 | laforge | |
14 | 1 | laforge | Towards the SGSN, the BSSGP and NS protocols are implemented over UDP/IP, sometimes called "NS over IP". |
15 | 19 | laforge | It has been tested with [[OsmoSGSN:]] as well as an Ericsson SGSN so far. |
16 | 1 | laforge | |
17 | 13 | laforge | osmo-pcu is now considered stable and already performing useful service for a number of users, but as one |
18 | 1 | laforge | of the more recent additions to the Osmocom family, there still is plenty of area for improvement. |
19 | 14 | jerlbeck | |
20 | 23 | laforge | h2. Position in a typical Osmocom network |
21 | |||
22 | {{graphviz_link() |
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23 | digraph G { |
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24 | rankdir = LR; |
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25 | OsmoBTS -> OsmoBSC [label="Abis/IP"]; |
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26 | OsmoBSC -> OsmoMSC [label="3GPP AoIP"]; |
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27 | OsmoBTS -> OsmoPCU [label="pcu_sock"]; |
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28 | OsmoPCU -> OsmoSGSN [label="Gb/IP"]; |
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29 | OsmoMSC -> OsmoHLR [label="GSUP"]; |
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30 | OsmoSGSN -> OsmoHLR [label="GSUP"]; |
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31 | OsmoSGSN -> OsmoGGSN [label="Gp"]; |
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32 | OsmoGGSN -> Internet [label="Gi"]; |
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33 | OsmoPCU [color=red]; |
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34 | } |
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35 | }} |
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36 | |||
37 | |||
38 | 17 | laforge | h2. Manuals |
39 | 11 | laforge | |
40 | 17 | laforge | * User Manual: http://ftp.osmocom.org/docs/latest/osmopcu-usermanual.pdf |
41 | * VTY Reference: http://ftp.osmocom.org/docs/latest/osmopcu-vty-reference.pdf |
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42 | 20 | laforge | * Gb/IP Manual: http://ftp.osmocom.org/docs/latest/osmopcu-gb.pdf |
43 | 16 | laforge | |
44 | 17 | laforge | h2. Source Code |
45 | |||
46 | 1 | laforge | The source code is available from git://git.osmocom.org/osmo-pcu.git |
47 | |||
48 | You can browse it online via http://cgit.osmocom.org/cgit/osmo-pcu/ |
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49 | |||
50 | 25 | laforge | h2. Test Suite |
51 | |||
52 | We have a TTCN-3 test suite as part of our [[cellular-infrastructure:Titan_TTCN3_Testsuites]] |
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53 | * source code: http://git.osmocom.org/osmo-ttcn3-hacks/tree/pcu |
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54 | * results: https://jenkins.osmocom.org/jenkins/view/TTCN3/job/ttcn3-pcu-test/ |
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55 | |||
56 | 16 | laforge | h2. Mailing List |
57 | |||
58 | There is a mailing list for (development) discussion regarding the PCU: osmocom-net-gprs@lists.osmocom.org |
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59 | 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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60 | 1 | laforge | |
61 | 21 | laforge | Please make sure to read our [[cellular-infrastructure:MailingListRules]] before posting. |
62 | 16 | laforge | |
63 | h3. Supported |
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64 | |||
65 | * GPRS CS1 to CS4 with dynamic link/rate adaption |
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66 | 1 | laforge | * EDGE MCS1-MCS9 with dynamic link/rate adaption |
67 | 16 | laforge | * Single-slot and multi-slot operation on downlink |
68 | * Single-slot operation on uplink |
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69 | * Independent TFI/USF per PDCH in single-slot allocation mode |
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70 | * Automatic or fixed PDCH allocation algorithm selection |
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71 | * Delayed release of downlink TBF |
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72 | * Active queue management for downlink TBF (!CoDel) |
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73 | * Initial setting of timing advance based on RACH |
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74 | * BSSGP BVC flow control support |
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75 | 22 | neels | * Using pchan types of @TCH/F_TCH/H_PDCH@ or @TCH/F_PDCH@, OsmoBTS supports |
76 | dynamic PDCH/TCH switching (implemented entirely in osmo-bts) |
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77 | 1 | laforge | |
78 | |||
79 | 16 | laforge | h3. Shortcomings / Limitations / Restrictions |
80 | 14 | jerlbeck | |
81 | 22 | neels | _Note: this list may be outdated_ |
82 | 16 | laforge | |
83 | * No GPRS/EGPRS mixed mode (yet) |
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84 | * No support for hand-over of any sort yet |
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85 | * No support of processing measurement reports |
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86 | * No timing advance loop, i.e. radial movement is limited |
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87 | * No support for power control |
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88 | * No Packet Access Reject message on congestion, access is just ignored |
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89 | * No PCCCH support |
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90 | * Only "Dynamic allocation RLC data block transfer" is supported |
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91 | * No network controlled measurement/cell reselection order supported |
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92 | * No PTCCH support |
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93 | * No support for Packet Flow Contexts (PFC) |
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94 | * No support for MS or PFC flow control |
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95 | * No support for RLC unacknowledged mode operation |
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96 | * No support for MBMS |
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97 | |||
98 | h2. Authors / Credits |
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99 | |||
100 | 1 | laforge | |
101 | osmo-pcu was originally developed by Ivan Kluchnikov and Andreas Everberg. |
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102 | |||
103 | 24 | msuraev | Today it is maintaned by Sysmocom. |