Project

General

Profile

OsmoPCU » History » Version 16

zecke2, 02/19/2016 10:48 PM

1 16 zecke2
{{>toc}}
2 1 laforge
3 16 zecke2
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 zecke2
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
13
[[OsmoTRX]].
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 zecke2
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 zecke2
h2. Source Code
23
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/
28
29
30
31 16 zecke2
h2. Mailing List
32
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
36
37
38 16 zecke2
h2. Status
39
40
Information about testing is available here: [[GPRS-testing]]
41
42
43
h3. Supported
44
45
* GPRS CS1 to CS4 with dynamic link/rate adaption
46 1 laforge
* EDGE MCS1-MCS9 with dynamic link/rate adaption
47 16 zecke2
* Single-slot and multi-slot operation on downlink
48
* Single-slot operation on uplink
49
* Independent TFI/USF per PDCH in single-slot allocation mode
50
* Automatic or fixed PDCH allocation algorithm selection
51
* Delayed release of downlink TBF
52
* Active queue management for downlink TBF (!CoDel)
53
* Initial setting of timing advance based on RACH
54
* BSSGP BVC flow control support
55 1 laforge
56
57 16 zecke2
h3. Shortcomings / Limitations / Restrictions
58 14 jerlbeck
59 16 zecke2
60
* No GPRS/EGPRS mixed mode (yet)
61
* Timeslots have to be assigned dedicated as a PDCH, no dynamic PDCH/TCH switching
62
* No support for hand-over of any sort yet
63
* No support of processing measurement reports
64
* No timing advance loop, i.e. radial movement is limited
65
* No support for power control
66
* No Packet Access Reject message on congestion, access is just ignored
67
* No PCCCH support
68
* Only "Dynamic allocation RLC data block transfer" is supported
69
* No network controlled measurement/cell reselection order supported
70
* No PTCCH support
71
* No support for Packet Flow Contexts (PFC)
72
* No support for MS or PFC flow control
73
* No support for RLC unacknowledged mode operation
74
* No support for MBMS
75
76
77
h2. Authors / Credits
78
79 1 laforge
80
osmo-pcu was originally developed by Ivan Kluchnikov and Andreas Everberg.
81
82
Today it is maintaned by Jacob Erlbeck at sysmocom.
Add picture from clipboard (Maximum size: 48.8 MB)