Project

General

Profile

OsmoTRX » History » Version 60

laforge, 06/13/2017 06:06 PM

1 41 sylvain
{{>toc}}
2 1 ttsou
3 41 sylvain
h1. [[OsmoTRX]]
4 1 ttsou
5 1 ttsou
6 41 sylvain
[[OsmoTRX]] is a software-defined radio transceiver that implements the Layer 1 physical layer of a BTS comprising the following 3GPP specifications:
7 41 sylvain
* TS 05.01 "Physical layer on the radio path"
8 41 sylvain
* TS 05.02 "Multiplexing and Multiple Access on the Radio Path"
9 41 sylvain
* TS 05.04 "Modulation"
10 41 sylvain
* TS 05.10 "Radio subsystem synchronization"
11 1 ttsou
12 49 neels
[[OsmoTRX]] is based on the transceiver code from the [[OsmoBTS:OpenBTS]] project, but setup to operate independently with the purpose of using with non-OpenBTS software and projects, while still maintaining backwards compatibility with [[OsmoBTS:OpenBTS]]. Currently there are numerous features contained in [[OsmoTRX:]] that extend the functionality of the [[OsmoBTS:OpenBTS]] transceiver. These features include enhanced support for various embedded platforms - notably ARM - and dual channel diversity support for the Fairwaves [[umtrx:]].
13 41 sylvain
14 46 laforge
h2. OsmoTRX in the Osmocom GSM architecture
15 46 laforge
16 46 laforge
{{graphviz_link()
17 46 laforge
digraph G {
18 46 laforge
    rankdir = LR;
19 46 laforge
    SDR -> OsmoTRX [label="Raw Samples"];
20 46 laforge
    OsmoTRX -> OsmoBTS [label="bursts over UDP"];
21 46 laforge
    OsmoBTS -> OsmoNITB [label="Abis/IP"];
22 46 laforge
    OsmoBTS -> OsmoPCU [label="pcu_sock"];
23 46 laforge
    OsmoPCU -> OsmoSGSN [label="Gb/IP"];
24 46 laforge
    OsmoTRX [color=red];
25 46 laforge
}
26 46 laforge
}}
27 41 sylvain
28 41 sylvain
h2. Features
29 41 sylvain
30 41 sylvain
31 41 sylvain
*Intel SSE Support*
32 6 ttsou
* SSE3
33 6 ttsou
* SSE4.1
34 20 ttsou
35 41 sylvain
On Intel processors, [[OsmoTRX]] makes heavy use of the Streaming SIMD Extensions (SSE) instruction set. Accelerated operations include pulse shape filtering, resampling, sequence correlation, and many other signal processing operations. SSE3 is the minimum requirement for accelerated use.
36 1 ttsou
37 20 ttsou
SSE3 is present in the majority of Intel processors since later versions of the Pentium 4 architecture and is also present on low power Atom processors. Support is automatically detected at build time. For additional performance information, please see the performance and benchmarks section.
38 29 ttsou
39 41 sylvain
*ARM Support*
40 1 ttsou
* NEON
41 1 ttsou
* NEON-VFPv4
42 20 ttsou
43 41 sylvain
[[OsmoTRX]] runs on a variety of ARM processors with and without NEON coprocessors. Like SSE on Intel processors, NEON provides acceleration with SIMD vectorized instructions.
44 20 ttsou
45 1 ttsou
Tested popular architectures include ARM11 (Raspberry Pi), Cortex-A8 (!BeagleBoard), and Cortex-A15 (!ArndaleBoard). Loosely speaking, these platforms are representative of low cost embedded devices, mid-level handsets, and high-end smartphones respectively. Similarly, in order, these platforms include no NEON coprocessor, standard NEON, and NEON-VFPv4. The latter NEON variation, VFPv4, provides additional fused-multiply-accumulate (FMA) instructions useful for many DSP operations.
46 1 ttsou
47 26 ttsou
NEON support must be enabled by the user at build time. For additional information, please see the configuration and performance and benchmarks sections.
48 37 ttsou
49 41 sylvain
*Dual Channel (UmTRX and B210)*
50 7 ttsou
51 1 ttsou
Two dual channel modes are available: standard dual channel mode and diversity. In standard dual channel mode, each RF
52 28 ttsou
path of the dual channel device supports a different ARFCN. Each path operates independently a
53 1 ttsou
nd operates similarly to two separate devices. GSM channel capacity in this mode is doubled. This option can be configured at run time from the command line.
54 1 ttsou
55 41 sylvain
*Dual Channel Diversity (UmTRX, experimental)*
56 1 ttsou
57 28 ttsou
Diversity mode is similar to the standard dual channel mode except each antenna supports both ARFCN channels. In this case, the receiver sample bandwidth is widened to handle both ARFCN's and subsequently converted and demultiplexed into separate sample streams. Each GSM receive path is fed dual signals, where antenna selection diversity is performed by taking the stronger signal on a burst-by-burst basis. This diversity setup improves uplink reception performance in multipath fading environments.
58 16 ttsou
59 28 ttsou
Limitations are increased CPU utilization and that ARFCN spacing is restricted (currently at 400 kHz) by the receiver sampling bandwidth. Setting the ARFCN spacing beyond the sampling limit will disable the diversity path and operate in standard dual channel mode. This options can be configured at run time from the command line.
60 20 ttsou
61 41 sylvain
*Uplink Burst Detection*
62 39 ttsou
63 49 neels
[[OsmoTRX]] utilizes an updated receive burst detection algorithm that provides greater sensitivity and reliability than the original [[OsmoBTS:OpenBTS]] approach, which relied on energy detection for the initial stage of burst acquisition.
64 39 ttsou
65 1 ttsou
The limitation of the previous approach was that it was slow to adapt to highly transient power levels and false burst detection in challenging situations such as receiver saturation, which may occur in close range lab testing. The other issue was that a high degree of level tuning was often necessary to operate reliably.
66 1 ttsou
67 1 ttsou
The current receiver code addressed those limitations for improved performance in a wider variety of environments.
68 1 ttsou
69 41 sylvain
*Low Phase Error Modulator*
70 16 ttsou
71 16 ttsou
The default GSM downlink signal is configured for low distortion using a linearized GMSK modulator. The implementation is based on a two pulse Laurent approximation of continuous phase modulated (CPM) signals. The baseband output signal measures with very low phase error and is capable of passing industry spectrum mask requirements. Please note that actual performance will depend strongly on the particular device in use.
72 1 ttsou
73 41 sylvain
Theoretical details can be found in the report on "GMSK":http://tsou.cc/gsm/report_gmsk.pdf. Octave / Matlab code for "pulse generation":http://tsou.cc/gsm/laurent.m is also available.
74 1 ttsou
75 1 ttsou
This option can be enabled or disabled at run time from the command line.
76 28 ttsou
77 28 ttsou
Very Low Phase Error (Ettus Research N200)
78 16 ttsou
79 58 ipse
!osmo-trx-phase.gif!
80 1 ttsou
81 21 ttsou
Spectrum Mask (Ettus Research N200)
82 1 ttsou
83 58 ipse
!osmo-trx-spectrum.gif!
84 1 ttsou
85 41 sylvain
h2. RF Hardware support
86 1 ttsou
87 1 ttsou
88 50 neels
Multiple RF devices are currently supported. These include USRP family products from Ettus Research, and the [[UmTRX:]] from Fairwaves.
89 41 sylvain
90 1 ttsou
more details (e.g. signal levels) are provided in the hardware specific pages:
91 60 laforge
{{child_pages(HardwareSupport)}}
92 59 roh
93 41 sylvain
h2. Embedded Platform Support
94 1 ttsou
95 41 sylvain
96 41 sylvain
[[OsmoTRX]] has been tested on the multiple embedded platforms representing a wide range of device types. Low cost ARM devices are generally limited by memory and I/O as much CPU utilization.
97 41 sylvain
98 1 ttsou
Running a full or near full ARFCN configuration (7 simultaneous TCH channels with Combination V) may require running the GSM stack remotely, which can be configured at runtime on the command line. This limitation appears to be scheduling related more so than lack of CPU resources, and may be resolved at a later time.
99 1 ttsou
100 43 laforge
|_.Platform|_.SoC*|_.Processor|_.SIMD/FPU|_.Testing Notes|
101 43 laforge
|ArndaleBoard|Samsung Exynos 5250|ARM Cortex-A15|NEON-VFPv4|7 TCH|
102 43 laforge
|BeagleBoard-xM|Texas Instruments OMAP3|ARM Cortex-A8|NEON|7 TCH, remote [[osmobts:]] stack|
103 43 laforge
|Ettus E100|Texas Instruments OMAP3|ARM Cortex-A8|NEON|7 TCH, remote [[osmobts:]] stack|
104 43 laforge
|Raspberry Pi|Broadcom BCM2835|ARM11|VFP|2 TCH, remote [[osmobts:]] stack|
105 43 laforge
|Shuttle PC|NA|Intel Atom D2550|SSE3|Dual channel, 15 TCH|
106 1 ttsou
107 1 ttsou
All embedded plaforms were tested with low-phase error modulator disabled. Use of the more accurate modulator on embedded platforms has not been extensively tested.
108 19 ttsou
109 41 sylvain
h2. Mailing List
110 22 ttsou
111 41 sylvain
112 49 neels
For development purposes, [[OsmoTRX:]] is discussed on both [[OsmoBTS:OpenBTS]] and [[OpenBSC:]] mailing lists at openbts-discuss@lists.sourceforge.net and openbsc@lists.osmocom.org respectively.
113 41 sylvain
114 1 ttsou
Please direct questions and bug reports to the list appropriate for the GSM stack being used.
115 41 sylvain
116 47 laforge
Subscription information is available at "and [http://lists.osmocom.org/mailman/listinfo/openbsc/":https://lists.sourceforge.net/lists/listinfo/openbts-discuss].  Please make sure to read our [[cellular-infrastructure:MailingListRules]] before posting.
117 1 ttsou
118 41 sylvain
h2. GPRS support
119 1 ttsou
120 1 ttsou
121 44 laforge
[[OsmoTRX]] supports GPRS through [[osmobts:]].
122 1 ttsou
123 49 neels
For GPRS support with [[OsmoBTS:OpenBTS]], please use the transceiver supplied with [[OsmoBTS:OpenBTS]].
124 41 sylvain
125 41 sylvain
126 41 sylvain
h2. Source code
127 41 sylvain
128 41 sylvain
129 1 ttsou
The source code is available from git.osmocom.org (module osmo-trx).
130 18 ttsou
131 18 ttsou
Public read-only access is available via
132 41 sylvain
<pre>
133 19 ttsou
$ git clone git://git.osmocom.org/osmo-trx
134 41 sylvain
</pre>
135 1 ttsou
You can browse it via cgit: http://cgit.osmocom.org/cgit/osmo-trx/
136 1 ttsou
137 48 neels
h2. Dependencies
138 1 ttsou
139 48 neels
Install libusb-1.0 and libbost dev packages. On debian 8.4:
140 1 ttsou
141 48 neels
<pre>
142 48 neels
sudo apt-get install --no-install-recommends libusb-1.0-0-dev libboost-dev
143 48 neels
</pre>
144 41 sylvain
145 53 neels
h3. UHD
146 1 ttsou
147 48 neels
Unless using USRP1, you will need the Universal Hardware Driver (UHD),
148 48 neels
which is available from Ettus Research or Fairwaves; the UHD implementation
149 48 neels
must match your hardware:
150 48 neels
151 48 neels
* Ettus Research UHD for USRP devices
152 51 neels
* Fairwaves UHD with [[UmTRX:]]
153 48 neels
* USRP1 does not use the UHD driver, it is supported through the legacy libusrp driver provided in GNU Radio 3.4.2.
154 48 neels
155 55 wirelesss
h3. UHD for Debian
156 48 neels
157 52 neels
When you are reading this, Debian packages for UHD may be sufficient for running osmo-trx and osmo-bts-trx.
158 48 neels
here are some of the packages that need to be installed:
159 48 neels
160 48 neels
<pre>
161 54 neels
sudo apt-get install libuhd-dev uhd-host
162 48 neels
</pre>
163 1 ttsou
164 55 wirelesss
*Troubleshooting:*
165 55 wirelesss
 
166 52 neels
At the time of writing this (2016-12), for Debian 8 aka jessie you need to use the jessie-backports packages:
167 52 neels
168 52 neels
<pre>
169 52 neels
sudo -s
170 52 neels
echo "deb http://ftp.de.debian.org/debian jessie-backports main" > /etc/apt/sources.list.d/uhd.list
171 52 neels
apt-get update
172 52 neels
apt-get -t jessie-backports install libuhd-dev uhd-host
173 52 neels
</pre>
174 52 neels
175 52 neels
It may also be possible to use the pothos PPA instead:
176 48 neels
177 48 neels
<pre>
178 48 neels
sudo add-apt-repository ppa:guruofquality/pothos
179 48 neels
sudo apt-get update
180 48 neels
sudo apt install libboost-dev uhd
181 48 neels
</pre>
182 48 neels
183 53 neels
h3. Firmware
184 48 neels
185 48 neels
You also need to download the firmware using a script provided by the UHD package.
186 48 neels
Instructions suggest running the script as root, but this way is less dangerous:
187 48 neels
188 48 neels
<pre>
189 48 neels
sudo mkdir /usr/share/uhd
190 48 neels
sudo chown $USER: /usr/share/uhd
191 48 neels
/usr/lib/uhd/utils/uhd_images_downloader.py
192 48 neels
</pre>
193 48 neels
194 53 neels
h3. Group
195 48 neels
196 48 neels
You may need to add yourself to the usrp group:
197 48 neels
198 48 neels
<pre>
199 48 neels
sudo gpasswd -a $USER usrp
200 48 neels
# and re-login to acquire the group
201 48 neels
</pre>
202 48 neels
203 53 neels
h3. Verify
204 48 neels
205 48 neels
run uhd_find_devices to make sure b200 is available:
206 48 neels
207 48 neels
<pre>
208 48 neels
$ uhd_find_devices 
209 48 neels
linux; GNU C++ version 4.9.1; Boost_105500; UHD_003.007.003-0-unknown
210 48 neels
211 48 neels
--------------------------------------------------
212 48 neels
-- UHD Device 0
213 48 neels
--------------------------------------------------
214 48 neels
Device Address:
215 48 neels
    type: b200
216 48 neels
    name: MyB210
217 48 neels
    serial: 1C0FFEE
218 48 neels
    product: B210
219 48 neels
</pre>
220 48 neels
221 48 neels
h2. Configuration and Build
222 48 neels
223 41 sylvain
First, run autoreconf to remake the build system files.
224 1 ttsou
<pre>
225 18 ttsou
$ autoreconf -i
226 41 sylvain
...
227 18 ttsou
</pre>
228 41 sylvain
229 18 ttsou
*Intel Platforms (All)*
230 1 ttsou
231 41 sylvain
Intel SSE support is automatically detected on Intel x86 platforms. No user intervention is necessary. The general configuration defaults to the low phase error modulator. Atom users may wish to use the low-CPU utilization modulator, which can be later enabled from the command line at runtime.
232 18 ttsou
<pre>
233 1 ttsou
$ ./configure
234 1 ttsou
...
235 19 ttsou
checking whether mmx is supported... yes
236 18 ttsou
checking whether sse is supported... yes
237 18 ttsou
checking whether sse2 is supported... yes
238 18 ttsou
checking whether sse3 is supported... yes
239 18 ttsou
checking whether ssse3 is supported... yes
240 18 ttsou
checking whether sse4.1 is supported... yes
241 18 ttsou
checking whether sse4.2 is supported... yes
242 41 sylvain
...
243 18 ttsou
</pre>
244 41 sylvain
245 18 ttsou
*ARM Platforms with NEON*
246 41 sylvain
247 41 sylvain
Many popular ARM development boards fall under this category including BeagleBoard, PandaBoard, and Ettus E100 USRP. This option will disable the low phase error modulator, which can be re-enabled at runtime. NEON support must be manually enabled.
248 24 ttsou
<pre>
249 41 sylvain
$ ./configure --with-neon
250 1 ttsou
</pre>
251 41 sylvain
252 1 ttsou
*ARM Platforms with NEON-VFPv4*
253 41 sylvain
254 41 sylvain
Currently very few development platforms support this instruction set, which is seen mainly in high end smartphones and tablets. Available development boards are ArndaleBoard and ODROID-XU. This option will disable the low phase error modulator, which can be re-enabled at runtime. NEON-VFPv4 support must be manually enabled.
255 1 ttsou
<pre>
256 41 sylvain
$ ./configure --with-neon-vfpv4
257 1 ttsou
</pre>
258 41 sylvain
259 1 ttsou
*ARM Platforms without NEON*
260 41 sylvain
261 1 ttsou
This configuration mainly targets the Raspberry Pi. ARM platforms without NEON vector units are almost always very slow processors, and generally not very suitable for running [[OsmoTRX]]. Running [[OsmoTRX]] on a Raspberry Pi, however, is possible along with limited TCH (voice) channel support. Currently this configuration requires minor code changes.
262 1 ttsou
263 1 ttsou
Coming soon...
264 41 sylvain
265 1 ttsou
*Build and Install*
266 16 ttsou
267 16 ttsou
After configuration, installation is simple.
268 41 sylvain
269 16 ttsou
<pre>
270 16 ttsou
$ make
271 41 sylvain
$ sudo make install
272 16 ttsou
</pre>
273 16 ttsou
274 41 sylvain
h2. Running
275 16 ttsou
276 56 wirelesss
Normally simply start osmo-trx.
277 41 sylvain
278 56 wirelesss
<pre>
279 56 wirelesss
$ osmo-trx
280 56 wirelesss
linux; GNU C++ version 5.3.1 20151219; Boost_105800; UHD_003.009.002-0-unknown
281 56 wirelesss
282 56 wirelesss
opening configuration table from path :memory:
283 56 wirelesss
Config Settings
284 56 wirelesss
   Log Level............... NOTICE
285 56 wirelesss
   Device args............. 
286 56 wirelesss
   TRX Base Port........... 5700
287 56 wirelesss
   TRX Address............. 127.0.0.1
288 56 wirelesss
   Channels................ 1
289 56 wirelesss
   Tx Samples-per-Symbol... 4
290 56 wirelesss
   Rx Samples-per-Symbol... 1
291 56 wirelesss
   EDGE support............ Disabled
292 56 wirelesss
   Reference............... Internal
293 56 wirelesss
   C0 Filler Table......... Disabled
294 56 wirelesss
   Multi-Carrier........... Disabled
295 56 wirelesss
   Diversity............... Disabled
296 56 wirelesss
   Tuning offset........... 0
297 56 wirelesss
   RSSI to dBm offset...... 0
298 56 wirelesss
   Swap channels........... 0
299 56 wirelesss
300 56 wirelesss
-- Detected Device: B200
301 56 wirelesss
-- Loading FPGA image: /usr/share/uhd/images/usrp_b200_fpga.bin... done
302 56 wirelesss
-- Operating over USB 2.
303 56 wirelesss
-- Detecting internal GPSDO.... No GPSDO found
304 56 wirelesss
-- Initialize CODEC control...
305 56 wirelesss
-- Initialize Radio control...
306 56 wirelesss
-- Performing register loopback test... pass
307 56 wirelesss
-- Performing CODEC loopback test... pass
308 56 wirelesss
-- Asking for clock rate 16.000000 MHz... 
309 56 wirelesss
-- Actually got clock rate 16.000000 MHz.
310 56 wirelesss
-- Performing timer loopback test... pass
311 56 wirelesss
-- Setting master clock rate selection to 'automatic'.
312 56 wirelesss
-- Asking for clock rate 26.000000 MHz... 
313 56 wirelesss
-- Actually got clock rate 26.000000 MHz.
314 56 wirelesss
-- Performing timer loopback test... pass
315 56 wirelesss
-- Setting B200 4/1 Tx/Rx SPS
316 56 wirelesss
-- Transceiver active with 1 channel(s)
317 56 wirelesss
</pre>
318 56 wirelesss
319 41 sylvain
[[OsmoTRX]] can be configured with a variety of options on the command line. In most cases, the default settings will suffice. Notable options include UHD device argument passing, which is often useful for using network based devices with firewalls, and external 10 MHz reference support.
320 41 sylvain
321 16 ttsou
<pre>
322 16 ttsou
$ osmo-trx -h
323 16 ttsou
linux; GNU C++ version 4.8.1 20130603 (Red Hat 4.8.1-1); Boost_105300; UHD_003.005.004-140-gfb32ed16
324 16 ttsou
325 16 ttsou
Options:
326 1 ttsou
  -h    This text
327 16 ttsou
  -a    UHD device args
328 16 ttsou
  -l    Logging level (EMERG, ALERT, CRT, ERR, WARNING, NOTICE, INFO, DEBUG)
329 1 ttsou
  -i    IP address of GSM core
330 1 ttsou
  -p    Base port number
331 16 ttsou
  -d    Enable dual channel diversity receiver
332 16 ttsou
  -x    Enable external 10 MHz reference
333 38 ttsou
  -s    Samples-per-symbol (1 or 4)
334 38 ttsou
  -c    Number of ARFCN channels (default=1)
335 16 ttsou
  -f    Enable C0 filler table
336 41 sylvain
  -o    Set baseband frequency offset (default=auto)
337 16 ttsou
</pre>
338 41 sylvain
339 1 ttsou
<pre>
340 16 ttsou
$ osmo-trx -a "addr=192.168.10.2"
341 16 ttsou
linux; GNU C++ version 4.8.1 20130603 (Red Hat 4.8.1-1); Boost_105300; UHD_003.004.000-b14cde5
342 16 ttsou
343 16 ttsou
Config Settings
344 1 ttsou
   Log Level............... INFO
345 16 ttsou
   Device args............. addr=192.168.10.2
346 1 ttsou
   TRX Base Port........... 5700
347 16 ttsou
   TRX Address............. 127.0.0.1
348 16 ttsou
   Channels................ 1
349 16 ttsou
   Samples-per-Symbol...... 4
350 16 ttsou
   External Reference...... Disabled
351 16 ttsou
   Diversity............... Disabled
352 41 sylvain
353 13 ttsou
-- Opening a [[UmTRX]] device...
354 38 ttsou
-- Current recv frame size: 1472 bytes
355 41 sylvain
-- Current send frame size: 1472 bytes
356 38 ttsou
-- Setting [[UmTRX]] 4 SPS
357 41 sylvain
-- Transceiver active with 1 channel(s)
358 38 ttsou
</pre>
359 1 ttsou
360 49 neels
h2. [[OsmoTRX]] with [[OsmoBTS:OpenBTS]]
361 38 ttsou
362 38 ttsou
363 49 neels
[[OsmoTRX]] is fully compatible with [[OsmoBTS:OpenBTS]] for voice and SMS services. Due to differences in handing of GPRS, [[OsmoTRX]] does not support GPRS when used with [[OsmoBTS:OpenBTS]], however, GPRS with the Osmocom stack is supported.
364 41 sylvain
365 49 neels
For use with [[OsmoBTS:OpenBTS]], enable the filler table option "Enable C0 filler table", which enables [[OsmoBTS:OpenBTS]] style idle bursts and retransmissions.
366 41 sylvain
367 41 sylvain
<pre>
368 1 ttsou
$ osmo-trx -f
369 41 sylvain
</pre>
370 17 ttsou
371 49 neels
The [[OsmoTRX]] transceiver should be started before running [[OsmoBTS:OpenBTS]]. No symbolic link to './transceiver' should exist in the [[OsmoBTS:OpenBTS]] directory. This prevents [[OsmoBTS:OpenBTS]] from starting its own transceiver instance.
372 35 ttsou
373 1 ttsou
h2. Authors
374 41 sylvain
375 1 ttsou
376 57 ttsou
[[OsmoTRX]] is currently maintained by Tom Tsou and Alexander Chemeris among others. The code is derived from the [[OsmoBTS:OpenBTS]] project, which was originally developed by David Burgess and Harvind Samra at Range Networks.
Add picture from clipboard (Maximum size: 48.8 MB)