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 |
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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. |
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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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25 | 1 | laforge | The source code is available from git://git.osmocom.org/osmo-pcu.git |
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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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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 |
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40 | Information about testing is available here: [[GPRS-testing]] |
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43 | h3. Supported |
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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 | |
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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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77 | h2. Authors / Credits |
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79 | 1 | laforge | |
80 | osmo-pcu was originally developed by Ivan Kluchnikov and Andreas Everberg. |
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82 | Today it is maintaned by Jacob Erlbeck at sysmocom. |