OsmoPCU » History » Version 14
jerlbeck, 02/19/2016 10:48 PM
update information about the PCU
1 | 3 | laforge | [[PageOutline]] |
---|---|---|---|
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. |
||
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 | 11 | laforge | [wiki:OsmoTRX]. |
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 | 13 | laforge | It has been tested with [wiki:osmo-sgsn] as well as an Ericsson SGSN so far. |
15 | 1 | laforge | |
16 | 14 | jerlbeck | osmo-pcu is now considered stable and already performing useful service for a number of users, but as one |
17 | 11 | laforge | of the more recent additions to the Osmocom family, there still is plenty of area for improvement. |
18 | 1 | laforge | |
19 | == Source Code == |
||
20 | |||
21 | The source code is available from git://git.osmocom.org/osmo-pcu.git |
||
22 | |||
23 | You can browse it online via http://cgit.osmocom.org/cgit/osmo-pcu/ |
||
24 | 4 | ipse | |
25 | 3 | laforge | |
26 | 1 | laforge | == Mailing List == |
27 | |||
28 | 10 | laforge | There is a mailing list for (development) discussion regarding the PCU: osmocom-net-gprs@lists.osmocom.org |
29 | You can subscribe to it (or manage your subscription) at http://lists.osmocom.org/cgi-bin/mailman/listinfo/osmocom-net-gprs |
||
30 | 3 | laforge | |
31 | == Status == |
||
32 | 5 | daniel | Information about testing is available here: [wiki:GPRS-testing] |
33 | 3 | laforge | |
34 | 1 | laforge | === Supported === |
35 | 14 | jerlbeck | * GPRS CS1 to CS4 with dynamic link/rate adaption |
36 | * Single-slot and multi-slot operation on downlink |
||
37 | * Single-slot operation on uplink |
||
38 | * Independent TFI/USF per PDCH in single-slot allocation mode |
||
39 | * Automatic or fixed PDCH allocation algorithm selection |
||
40 | * Delayed release of downlink TBF |
||
41 | * Active queue management for downlink TBF (!CoDel) |
||
42 | * Initial setting of timing advance based on RACH |
||
43 | * BSSGP BVC flow control support |
||
44 | 3 | laforge | |
45 | === Shortcomings / Limitations / Restrictions === |
||
46 | 1 | laforge | |
47 | * Pure GPRS PCU, no EGPRS (EDGE) functionality (yet) |
||
48 | 12 | laforge | * Timeslots have to be assigned dedicated as a PDCH, no dynamic PDCH/TCH switching |
49 | 7 | jolly | * No support for hand-over of any sort yet |
50 | * No support of processing measurement reports |
||
51 | 14 | jerlbeck | * No timing advance loop, i.e. radial movement is limited |
52 | * No support for power control |
||
53 | 1 | laforge | * No Packet Access Reject message on congestion, access is just ignored |
54 | * No PCCCH support |
||
55 | * Only "Dynamic allocation RLC data block transfer" is supported |
||
56 | * No network controlled measurement/cell reselection order supported |
||
57 | 7 | jolly | * No PTCCH support |
58 | 14 | jerlbeck | * No support for Packet Flow Contexts (PFC) |
59 | * No support for MS or PFC flow control |
||
60 | * No support for RLC unacknowledged mode operation |
||
61 | * No support for MBMS |
||
62 | 12 | laforge | |
63 | == Authors / Credits == |
||
64 | |||
65 | osmo-pcu was originally developed by Ivan Kluchnikov and Andreas Everberg. |
||
66 | |||
67 | Today it is maintaned by Holger Freyther and Jacob Erlbeck at sysmocom. |