582 lines
26 KiB
HTML
582 lines
26 KiB
HTML
<html>
|
|
<head>
|
|
<link href="style.css" rel="stylesheet" type="text/css" />
|
|
<title>osmocom-analog</title>
|
|
</head>
|
|
<body>
|
|
<center><table><tr><td>
|
|
|
|
<h2><center>C-Netz</center></h2>
|
|
|
|
<center><img src="c-netz.jpg"/></center>
|
|
|
|
<ul>
|
|
<li><a href="#history">History</a>
|
|
<li><a href="#howitworks">How it works</a>
|
|
<li><a href="#basestation">Setup of a base station</a>
|
|
</ul>
|
|
|
|
<p class="toppic">
|
|
<a name="history"></a>
|
|
History
|
|
</p>
|
|
|
|
<p>
|
|
C-Netz was the third mobile telephone network in Germany.
|
|
It existed between 1984 (officially Mai 1985) and December 2000.
|
|
In 1989, the German Wall came down and C-Netz was quickly deployed in eastern Germany to support the congested fixed network.
|
|
It was the first cellular system, so frequencies could be used more efficiently.
|
|
It offered handover capability, so moving phones could change cells during a call.
|
|
The SIM card was introduced, which is similar to GSM.
|
|
This card allowed to use phones by different subscribers with different subscriber numbers.
|
|
Authentication was used to prevent fraud, but it was used only with SIM card phones. The magnetic cards could be cloned by receiving 'roaming' messages.
|
|
Extra services (e.g. conditional call forwarding, answering machine) were installed in the mobile exchange.
|
|
A scrambler inside the phone and base station prevented eavedropping with radio scanners.
|
|
Phones became smaller and portable, even handheld phones were available.
|
|
All phones were available under a dedicated prefix, so the caller must not know the location of the phone anymore.
|
|
|
|
</p>
|
|
|
|
<center><img src="c-netz-c130.jpg"/></center>
|
|
|
|
<p>
|
|
<ul>
|
|
<li>Frequency range: 461.300 - 465.740 MHz (downlink); 451.300 - 465.740 MHz (uplink)
|
|
<li>222 voice channels
|
|
<li>237 voice channels since Mai 1988
|
|
<li>287 voice channels since September 1989
|
|
<li>1 organisation channel (call setup and paging)
|
|
<li>Duplex distance: 10 MHz
|
|
<li>Channel spacing: 10 KHz and optionally 12.5 KHz
|
|
<li>Voice modulation: FM
|
|
<li>Signalling modulation: carrier FSK
|
|
<li>Frequency deviation: 2.4 KHz (FSK)
|
|
<li>Mobile station transmit power: 50 mW up to 15 Watts
|
|
<li>Base station transmit power: 25 Watts
|
|
</ul>
|
|
</p>
|
|
|
|
|
|
<p class="toppic">
|
|
<a name="howitworks"></a>
|
|
How it works
|
|
</p>
|
|
|
|
<p>
|
|
Like AMPS (Advanced Mobile Phone Service), the C-Netz is a cellular network.
|
|
</p>
|
|
|
|
<center><img src="c-netz_zellstruktur.png"/></center>
|
|
|
|
<p>
|
|
Base stations are grouped into clusters.
|
|
Each cluster has arround 7 base stations.
|
|
Each base station in a cluster must have different channels.
|
|
As depictet, the frequency of a base station marked with "1" can be re-used in other clusters.
|
|
To handle more calls with the same amount of channels, the size of a cell must be reduced.
|
|
By using small cell structure, it is likely to loose radio link while calling and moving at the same time.
|
|
To prevent loss of radio link while moving to far away from a cell, handover to stronger or closer cell is performed.
|
|
</p>
|
|
|
|
<center><img src="c-netz_frequenzen.png"/></center>
|
|
|
|
<p>
|
|
Two frequency bands are used, one for uplink and one downlink.
|
|
Only one exception is the control channel "131".
|
|
It is the same for all base stations.
|
|
To avoid collisions, the channel is divided into time slots.
|
|
The time slots are re-used in the same way as channels are re-used in other clusters.
|
|
This reduces the number of channels for call setup to only one channel.
|
|
The mobile phone does not have to search for a valid control channel first.
|
|
Also it is possible to have a dedicated control channel for cells in high traffic areas.
|
|
</p>
|
|
|
|
<center><img src="c-netz_zeitschlitze.png"/></center>
|
|
|
|
<p>
|
|
As depicted, the base station and mobile station use one or more time slots.
|
|
Generally every 8th time slot is used.
|
|
In this case the base station transmits every 600ms.
|
|
The mobile phone transmits two time slots later.
|
|
Every time slot contains two message blocks.
|
|
One block is used for call setup.
|
|
The other block is used for periodic check if the phone is still available.
|
|
</p>
|
|
|
|
<p>
|
|
Message blocks contain 70 bits.
|
|
The first 6 bits define the message type.
|
|
The other 64 bits depend on the message type.
|
|
The 70 bits are grouped into 10 words of 7 bits each.
|
|
Eeach word gets 8 redudancy bits by using a BCH code.
|
|
The redundany allows to correct up to two bit errors in a word.
|
|
</p>
|
|
|
|
<center><img src="c-netz_interleaving.png"/></center>
|
|
|
|
<p>
|
|
To correct burst errors (several bit errors after each other), the bits are interleaved before transmitted.
|
|
As depicted above, the first bit of all words are transmitted first, then the next bit and so on.
|
|
</p>
|
|
|
|
<center><img src="c-netz_frame_k.png"/></center>
|
|
|
|
<p>
|
|
A sync word of 11 bits is added in front of each message three times.
|
|
Additional 14 guard bits are used to allow the transmitter to ramp up and down RF power between time slots.
|
|
</p>
|
|
|
|
<center><img src="c-netz_frame_v.png"/></center>
|
|
|
|
<p>
|
|
Also message blocks are transmitted during voice conversation.
|
|
The blocks are used to terminate the call, perform handover, measure link or transmit metering information.
|
|
4 bits the message is transmitted every 12.5 ms. After 600 ms, the complete frame is transmitted.
|
|
To remove the 4 bits from audio stream, the voice is time compressed (speed up) to 10/11th.
|
|
The 4 bits + 2 guard bits are transmitted in the 1/11th gap between voice chunks.
|
|
On the receiving end, the voice chunks are expanded again.
|
|
The phone will keep in sync with the voice chunks by keeping in sync with the message bits.
|
|
</p>
|
|
|
|
<center><img src="c-netz_frame_v2.png"/></center>
|
|
|
|
<p>
|
|
The level at the end of one voice chunk may not match the level of the beginning of the next chunk.
|
|
The offset must be removed by the receiver.
|
|
</p>
|
|
|
|
<center><img src="c-netz_lr.png"/></center>
|
|
|
|
<p>
|
|
This is an example of a broadcast message by a base station on the control channel.
|
|
The message type 'O' (letter o) is "100111", so this message block contains cell informations and access informations.
|
|
</p>
|
|
|
|
<center><img src="c-netz_symbole.png"/></center>
|
|
|
|
<p>
|
|
The location of parameters inside a message (information elements) are shown by letters.
|
|
Each letter is a different parameter as depicted above.
|
|
</p>
|
|
|
|
<center><img src="c-netz_call.png"/></center>
|
|
|
|
<p>
|
|
The first thing a phone does is looking for a strongest cell.
|
|
The phone accesses the cell by transmitting a location update message.
|
|
The cell acknowledges or rejects the phone.
|
|
</p>
|
|
|
|
<p>
|
|
The call setup is depiced above.
|
|
The mobile phone transmits a message that it wishes to make a normal call or emergency call.
|
|
If the channel is available, the base station requests the dialed number from the phone.
|
|
The phone transmits the dialed number.
|
|
If the number is ok, the base station acknowledges the dialed number.
|
|
After a voice channel is allocated, the phone is requested to change to that channel two time slots later.
|
|
On this voice channel, the mobe phone and the base station transmit 8 messages to prove quality of channel.
|
|
Messages VH1 and VHK are transmitted while the call is set up.
|
|
Then the phone is ordered to switch to voice conversation.
|
|
The following messages are transmitted between the voice chunks.
|
|
</p>
|
|
|
|
<p class="toppic">
|
|
<a name="basestation"></a>
|
|
Setup of a base station
|
|
</p>
|
|
|
|
<p>
|
|
When I first started with testing early C-Netz implementation, I had great trouble getting a response from a mobile phone.
|
|
The main problem was clock speed of the transmitted signal.
|
|
The base stations were all synchronized with a high precision clock.
|
|
All base stations transmit on the same control channel 131 ('Orgakanal'), but at different time slots.
|
|
The phone expects that the time slots repeat precisely every 2.4 seconds.
|
|
The specs say that the phone requires clock speed deviation of +- 1 PPM (Parts Per Million) or less.
|
|
To comply with the specs, the base stations needs to have a clock deviation far below 1 PPM.
|
|
(I guess that there is a tollerance, so maybe a few PPM deviation would make no big problem.)
|
|
We need to calibrate the speed of our transmit signal (and receive signal as well).
|
|
</p>
|
|
|
|
<p>
|
|
<font color="red">Importaint: We need calibrate the signal processing clock!</font>
|
|
</p>
|
|
|
|
<p>
|
|
First of all we need a reference clock.
|
|
Since most computer systems have standard crystals, we cannot use our system clock as reference without any help.
|
|
I decided to use the NTP daemon.
|
|
After running the system for several days, the clock speed should be accurate enough for our needs.
|
|
Be sure to choose a place for your PC with constant temperature.
|
|
</p>
|
|
|
|
<p>
|
|
In /etc/ntp.conf define one or more servers to get the time from. I suggest to use the German atom clock of the PTB:
|
|
</p>
|
|
|
|
<pre>
|
|
server ntp1.ptb.de
|
|
server ntp2.ptb.de
|
|
server ntp3.ptb.de
|
|
</pre>
|
|
|
|
<p>
|
|
This clock provides time base for European radio clocks and most German clocks.
|
|
It accurate enough for this project, so please use this clock.
|
|
</p>
|
|
|
|
<pre>
|
|
|
|
netbook ~ # ntptime
|
|
ntp_gettime() returns code 0 (OK)
|
|
time dad971f1.9e1b5c44 Sun, May 8 2016 10:06:09.617, (.617605507),
|
|
maximum error 238951 us, estimated error 199 us, TAI offset 0
|
|
ntp_adjtime() returns code 0 (<font color="red">OK</font>)
|
|
modes 0x0 (),
|
|
offset 425.797 us, frequency <font color="red">15.796 ppm</font>, interval 1 s,
|
|
maximum error 238951 us, estimated error 199 us,
|
|
status 0x2001 (PLL,NANO),
|
|
time constant 10, precision 0.001 us, tolerance 500 ppm,
|
|
|
|
</pre>
|
|
|
|
<p>
|
|
One notices that I have quite an unprecise crystal in my test machine.
|
|
Since I have NTP running, the system clock is now far below 1 PPM.
|
|
</p>
|
|
|
|
<p>
|
|
The second problem is the clock of our sound adapter.
|
|
They use own crystals.
|
|
Because they are made for audio signals (and not for high precise base stations), they can't be used without calibration.
|
|
Cheap USB adapters may even have different clocks on TX and RX.
|
|
I found out that the clock speed changes when the USB voltage changes.
|
|
The USB voltage changes, when the current changes, due to different volumes on the output.
|
|
To minimize this effect, don't use extension cables.
|
|
</p>
|
|
|
|
<p>
|
|
Since we have precise system clock now, we can measure the speed of our sound adapter.
|
|
Later we will use the measurement result to adjust our signal processor.
|
|
Be sure to have your machine running for at least 5 to 7 days (with your sound adapter attached, in case you have USB sound adapter).
|
|
The machine must have network connection to the NTP server.
|
|
I suggest to use 'ntp1.ptb.de' and 'ntp2.ptb.de' as reference.
|
|
Use command line option '-M' or '--measure' to measure my sound adapter.
|
|
Let it run for one hour.
|
|
</p>
|
|
|
|
<pre>
|
|
|
|
# src/cnetz/cnetz -k 131 -M
|
|
...
|
|
dsp.c:218 notice : Clock: RX=4.75 TX=36.84; Signal: RX=135.38 TX=-378.58 ppm
|
|
dsp.c:218 notice : Clock: RX=10.61 TX=31.09; Signal: RX=135.38 TX=-378.58 ppm
|
|
dsp.c:218 notice : Clock: RX=3.01 TX=26.55; Signal: RX=135.38 TX=-378.58 ppm
|
|
...
|
|
dsp.c:218 notice : Clock: RX=19.46 TX=19.45; Signal: RX=19.39 TX=19.42 ppm
|
|
dsp.c:218 notice : Clock: RX=19.45 TX=19.50; Signal: RX=19.39 TX=19.42 ppm
|
|
dsp.c:218 notice : Clock: RX=19.48 TX=19.47; Signal: RX=19.39 TX=19.42 ppm
|
|
dsp.c:218 notice : Clock: RX=19.44 TX=19.44; Signal: RX=19.35 TX=19.43 ppm
|
|
dsp.c:218 notice : Clock: RX=19.44 TX=19.49; Signal: RX=19.35 TX=19.43 ppm
|
|
|
|
</pre>
|
|
|
|
<p>
|
|
One can see that the measured clock from the sound card (sample rate) differs about +19.45 PPM.
|
|
Because I did not do any correction to the signal processing, the same error applies to the signal.
|
|
Use command line option '-S 19.45,19.45' or '--clock-speed 19.45,19.45' to compensate the clock error by adjusting the signal processor.
|
|
Let it run again for one hour and you will see that clock deviation is below 1 PPM.
|
|
</p>
|
|
|
|
<p>
|
|
<font color="red">Importaint: We need to connect to PLL and discriminator!</font>
|
|
</p>
|
|
|
|
<p>
|
|
C-Netz does not use a modulated tone to carry bits of information, instead it modulates the carrier directly.
|
|
This image shows the demodulated signal from a receiver:
|
|
</p>
|
|
|
|
<center><img src="c-netz-burst_full.png"/></center>
|
|
|
|
<p>
|
|
Generally a receiver will do de-emphasis and filtering after demodulating the signal.
|
|
We don't want that.
|
|
It may work, but be sure to get a receiver with disciminator output.
|
|
Many receivers can be modified, so search the Web for more infos.
|
|
</p>
|
|
|
|
<p>
|
|
On the transmitter we don't want to have filtering and pre-emphasis.
|
|
It may work, but be sure to get a transmitter that allows to disable emphasis.
|
|
I took the schematics of my transmitter and connected the sound card
|
|
directly to the PLL.
|
|
</p>
|
|
|
|
<p>
|
|
<font color="red">Importaint: We need to transmit correct polarity, use auto polarity detection always!</font>
|
|
</p>
|
|
|
|
<center><img src="c-netz-burst_part.png"/></center>
|
|
|
|
<p>
|
|
C-Netz uses FSK (Frequency Shift Keying) by directly modulating the carrier, rather than modulating a tone, which is then transmitted via FM.
|
|
The advantage is much higher data rate.
|
|
The base station's carrier frequency is raised by 2.5 KHz to transmit a logical "1" and lowered by 2.5 KHz to transmit a logial "0".
|
|
(The mobile station transmits reversed polarity.)
|
|
The mobile station will only detect the correct polarity.
|
|
The three sync words of "11100010010", is shown in the picture above.
|
|
In the picture above, the polarity is wrong.
|
|
(The logical "1" points down and the logical "0" points up.)
|
|
To change polarty, use command line option '-F yes|no|auto' or '--flip-polarity yes|no|auto'.
|
|
(Note: don't confuse with '-P'!)
|
|
</p>
|
|
|
|
<p>
|
|
The 'auto' option (default) will generate a signal of two base stations.
|
|
Since we have time division multiplex on the main control channel, we can transmit a second base station easily.
|
|
The second base station uses reversed polarity, so there is one base station with correct and one with wrong polarity.
|
|
The two base stations have different time slots and different IDs.
|
|
If a first registration message is received from the phone, we check which base station this response belongs to.
|
|
Then we found the correct polarity and turn off the base station with the wrong polarity.
|
|
</p>
|
|
|
|
<p>
|
|
The decoder itself does not care about what polarity it receives from the mobile station.
|
|
It just checks for sync words with both polarities and chooses right polarity automatically.
|
|
</p>
|
|
|
|
<p>
|
|
I have a transmitter and a receiver without emphasis, my soundcard has a clock error of about 19.2 PPM.
|
|
To run the base station I the following command line options:
|
|
</p>
|
|
|
|
<pre>
|
|
|
|
# cnetz -k 131 -E -e -S 19.25,19.25
|
|
...
|
|
cnetz.c:142 notice : You selected channel 131 ('Orga-Kanal') for combined callin
|
|
g + traffic channel. Some phones will reject this.
|
|
dsp.c:96 info : Using clock speed of 19.2 ppm (RX) and 19.2 ppm (TX) to correc
|
|
t sound card's clock.
|
|
cnetz.c:274 info : Entering IDLE state on channel 131.
|
|
Base station on channel 131 ready, please tune transmitter to 465.090 MHz and re
|
|
ceiver to 455.090 MHz.
|
|
|
|
</pre>
|
|
|
|
<p>
|
|
The sofware complains about using control channel 131 for voice traffic too.
|
|
This is the easiest way to use a single transmitter and receiver without switching.
|
|
But this is not compliant, so especially newer phone will reject this, like the Nokia C130.
|
|
Old phones like BSA, Storno or Phillips phones don't care.
|
|
When we make a call and another phone is regisered, the phone will loose coverage when we switch from control channel to traffic channel.
|
|
After the call, the other phone re-registers again.
|
|
</p>
|
|
|
|
<p>
|
|
You should tune the receiver to 465.090 first, to check if you can hear and decode the idle signal from the base station.
|
|
Then tune to actually uplink frequency 455.090 MHz.
|
|
The actual level is not yet relevant.
|
|
(You may check the quality using '-L 2' command line option and build a radio loop by tuning the receiver to the transmitter.)
|
|
</p>
|
|
|
|
<p>
|
|
Now power up a phone.
|
|
Depening on your card reader, insert chip or magnetic card.
|
|
Hopefully you get a response from the phone.
|
|
If it responds, you will hear a short burs on receiver.
|
|
This bursts is just 37.5 ms long and sounds a bit less noisy than the noise floor.
|
|
If the burst is received and correctly decoded, the base station knows the transmitter's polarty and selects it.
|
|
</p>
|
|
|
|
<pre>
|
|
|
|
telegramm.c:1486 info : RX Level: 96% Jitter: 0.04 Sync Time: 3968.18 (TS 10.02) POSITIVE
|
|
***********************************************
|
|
*** Autoselecting positive FSK TX polarity! ***
|
|
***********************************************
|
|
cnetz.c:895 info : Received Attachment 'Einbuchen' message from Subscriber '6215784' with chip card's security code 11029
|
|
transaction.c:208 info : Transaction state IDLE -> EM
|
|
transaction.c:70 info : Created transaction for subscriber '6215784'
|
|
database.c:117 info : Adding subscriber '6,2,15784' to database.
|
|
database.c:121 info : Subscriber '6,2,15784' busy now.
|
|
cnetz.c:709 notice : Frame sync offset = 800.18, correcting!
|
|
cnetz.c:760 info : Sending acknowledgement 'Einbuchquittung' to Attachment request.
|
|
database.c:124 info : Subscriber '6,2,15784' idle now.
|
|
transaction.c:89 info : Destroying transaction for subscriber '6215784'
|
|
transaction.c:208 info : Transaction state EM -> IDLE
|
|
|
|
</pre>
|
|
|
|
<p>
|
|
Level adjustment:
|
|
We see a receive level of arround 96%.
|
|
This is already good, since I did the adjustment previously.
|
|
Tune your receiver to the uplink frequency, so you get loopback of base station broadcast.
|
|
Use the variable resistor (connecting your transmitter) to adjust the volume until the RX level matches the same level of your previously received bust.
|
|
In my case I adjust the transmitter to match arround 96%. (+- 10% is good)
|
|
Now, whatever frequency deviation the phone transmits for signalling, so does your base station.
|
|
Use the other variable resistor (connecting your receviver) to adjust the volume until the level matches about 100%. (+- 10% is good)
|
|
Switch back the receiver to uplink frequency and restart the phone.
|
|
</p>
|
|
|
|
<p>
|
|
After some time (1 minute) the base station will check, if the phone is still available.
|
|
It transmits a request (MA) to the phone.
|
|
The phone answers to the request (MFT):
|
|
</p>
|
|
|
|
<pre>
|
|
|
|
telegramm.c:1473 info : Ignoring mysterious unmodulated telegramm (noise from phone's transmitter)
|
|
database.c:72 info : Check, if subscriber '6,2,15784' is still available.
|
|
transaction.c:208 info : Transaction state IDLE -> MA
|
|
transaction.c:70 info : Created transaction for subscriber '6215784'
|
|
database.c:121 info : Subscriber '6,2,15784' busy now.
|
|
cnetz.c:863 info : Sending keepalive request 'Meldeaufruf'
|
|
transaction.c:208 info : Transaction state MA -> MFT
|
|
telegramm.c:1486 info : RX Level: 96% Jitter: 0.02 Sync Time: 6534.01 (TS 16.50) POSITIVE
|
|
cnetz.c:969 info : Received acknowledge 'Meldung Funktelefonteilnehmer' message from Subscriber '6215784'
|
|
database.c:124 info : Subscriber '6,2,15784' idle now.
|
|
transaction.c:89 info : Destroying transaction for subscriber '6215784'
|
|
transaction.c:208 info : Transaction state MFT -> IDLE
|
|
|
|
</pre>
|
|
|
|
<p>
|
|
To make a call from the phone to the base station, just enter some digits and press the dial button on the phone.
|
|
The phone requests a call (VWG).
|
|
The base station requests dialed number (WAF).
|
|
The phone transmits dialed number (WUE).
|
|
The base station acknowledges the call (WBP) and then orders the phone to switch to speech channel (VAG).
|
|
Then measurement and through connection of speech takes place:
|
|
</p>
|
|
|
|
<pre>
|
|
|
|
telegramm.c:1486 info : RX Level: 96% Jitter: 0.04 Sync Time: 12671.99 (TS 32.00) POSITIVE
|
|
cnetz.c:931 info : Received outgoing Call 'Verbindungswunsch gehend' message from Subscriber '6215784'
|
|
transaction.c:208 info : Transaction state IDLE -> VWG
|
|
transaction.c:70 info : Created transaction for subscriber '6215784'
|
|
database.c:121 info : Subscriber '6,2,15784' busy now.
|
|
cnetz.c:854 info : Sending acknowledgement 'Wahlaufforderung' to outging call
|
|
transaction.c:208 info : Transaction state VWG -> WAF
|
|
telegramm.c:1486 info : RX Level: 95% Jitter: 0.04 Sync Time: 3366.02 (TS 8.50) POSITIVE
|
|
cnetz.c:957 info : Received dialing digits 'Wahluebertragung' message from Subscriber '6215784' to Number '02123839349'
|
|
transaction.c:208 info : Transaction state WAF -> WBP
|
|
cnetz.c:782 info : Sending call accept 'Wahlbestaetigung positiv'.
|
|
transaction.c:208 info : Transaction state WBP -> VAG
|
|
cnetz.c:789 info : Sending channel assignment 'Verbindungsaufbau gehend'.
|
|
transaction.c:208 info : Transaction state VAG -> BQ
|
|
cnetz.c:807 info : Staying on combined calling + traffic channel 131
|
|
dsp.c:641 info : Switching channel (mode)
|
|
cnetz.c:1014 info : Sending 'Belegungsquittung' on traffic channel
|
|
cnetz.c:1014 info : Sending 'Belegungsquittung' on traffic channel
|
|
cnetz.c:1014 info : Sending 'Belegungsquittung' on traffic channel
|
|
telegramm.c:1486 info : RX Level: 96% Jitter: 0.02 Sync Time: 9504.02 (TS 24.00) POSITIVE
|
|
cnetz.c:1118 info : Received allocation 'Belegung' message.
|
|
cnetz.c:1014 info : Sending 'Belegungsquittung' on traffic channel
|
|
telegramm.c:1486 info : RX Level: 96% Jitter: 0.02 Sync Time: 9701.99 (TS 24.50) POSITIVE
|
|
cnetz.c:1118 info : Received allocation 'Belegung' message.
|
|
...
|
|
transaction.c:208 info : Transaction state BQ -> VHQ
|
|
telegramm.c:1486 info : RX Level: 96% Jitter: 0.03 Sync Time: 10494.00 (TS 26.50) POSITIVE
|
|
cnetz.c:1118 info : Received allocation 'Belegung' message.
|
|
cnetz.c:1024 info : Sending 'Quittung Verbindung halten' on traffic channel
|
|
telegramm.c:1486 info : RX Level: 96% Jitter: 0.03 Sync Time: 10691.98 (TS 27.00) POSITIVE
|
|
cnetz.c:1118 info : Received allocation 'Belegung' message.
|
|
...
|
|
call.c:623 info : Incomming call from '6215784' to '02123839349'
|
|
transaction.c:208 info : Transaction state VHQ -> DS
|
|
telegramm.c:1486 info : RX Level: 96% Jitter: 0.02 Sync Time: 11286.00 (TS 28.50) POSITIVE
|
|
cnetz.c:1145 info : Received connection hold 'Verbindung halten' message.
|
|
cnetz.c:1051 info : Sending 'Durchschalten' on traffic channel
|
|
telegramm.c:1486 info : RX Level: 96% Jitter: 0.03 Sync Time: 11483.99 (TS 29.00) POSITIVE
|
|
cnetz.c:1145 info : Received connection hold 'Verbindung halten' message.
|
|
...
|
|
telegramm.c:1486 info : RX Level: 96% Jitter: 0.03 Sync Time: 12276.00 (TS 31.00) POSITIVE
|
|
cnetz.c:1131 info : Received assignment confirm 'Durchschaltung Quittung' message.
|
|
cnetz.c:1051 info : Sending 'Durchschalten' on traffic channel
|
|
telegramm.c:1486 info : RX Level: 97% Jitter: 0.02 Sync Time: 12474.01 (TS 31.50) POSITIVE
|
|
cnetz.c:1131 info : Received assignment confirm 'Durchschaltung Quittung' message.
|
|
...
|
|
transaction.c:208 info : Transaction state DS -> VHQ
|
|
telegramm.c:1486 info : RX Level: 96% Jitter: 0.03 Sync Time: 1781.99 (TS 4.50) POSITIVE
|
|
cnetz.c:1131 info : Received assignment confirm 'Durchschaltung Quittung' message.
|
|
dsp.c:641 info : Switching channel (mode)
|
|
cnetz.c:1238 info : Sending 'Quittung Verbindung halten' on traffic channel
|
|
cnetz.c:1238 info : Sending 'Quittung Verbindung halten' on traffic channel
|
|
cnetz.c:1238 info : Sending 'Quittung Verbindung halten' on traffic channel
|
|
telegramm.c:1486 info : RX Level: 97% Jitter: 0.07 Sync Time: 5544.05 (TS 14.00) POSITIVE
|
|
cnetz.c:1286 info : Received supervisory frame 'Verbindung halten' message.
|
|
cnetz.c:1238 info : Sending 'Quittung Verbindung halten' on traffic channel
|
|
telegramm.c:1486 info : RX Level: 97% Jitter: 0.07 Sync Time: 8712.02 (TS 22.00) POSITIVE
|
|
cnetz.c:1286 info : Received supervisory frame 'Verbindung halten' message.
|
|
cnetz.c:1238 info : Sending 'Quittung Verbindung halten' on traffic channel
|
|
telegramm.c:1486 info : RX Level: 97% Jitter: 0.09 Sync Time: 11880.04 (TS 30.00) POSITIVE
|
|
cnetz.c:1286 info : Received supervisory frame 'Verbindung halten' message.
|
|
cnetz.c:1238 info : Sending 'Quittung Verbindung halten' on traffic channel
|
|
...
|
|
|
|
</pre>
|
|
|
|
<p>
|
|
When calling to the phone, enter the mobile station's ID and press 'd' for dial.
|
|
If the phone is attached, the base station orders the phone to switch to speech channel (VAK).
|
|
The rest is similar to incomming calls, excpet the the phone has to answer before the speech is throughconnected:
|
|
</p>
|
|
|
|
<pre>
|
|
|
|
call.c:490 info : Outgoing call to 6215784
|
|
cnetz.c:416 info : Call to mobile station, paging station id '6215784'
|
|
transaction.c:208 info : Transaction state IDLE -> VAK
|
|
transaction.c:70 info : Created transaction for subscriber '6215784'
|
|
database.c:121 info : Subscriber '6,2,15784' busy now.
|
|
cnetz.c:792 info : Sending channel assignment 'Verbindungsaufbau kommend'.
|
|
transaction.c:208 info : Transaction state VAK -> BQ
|
|
cnetz.c:807 info : Staying on combined calling + traffic channel 131
|
|
dsp.c:641 info : Switching channel (mode)
|
|
cnetz.c:1014 info : Sending 'Belegungsquittung' on traffic channel
|
|
cnetz.c:1014 info : Sending 'Belegungsquittung' on traffic channel
|
|
cnetz.c:1014 info : Sending 'Belegungsquittung' on traffic channel
|
|
telegramm.c:1486 info : RX Level: 96% Jitter: 0.03 Sync Time: 6335.99 (TS 16.00) POSITIVE
|
|
cnetz.c:1118 info : Received allocation 'Belegung' message.
|
|
cnetz.c:1014 info : Sending 'Belegungsquittung' on traffic channel
|
|
telegramm.c:1486 info : RX Level: 95% Jitter: 0.03 Sync Time: 6534.06 (TS 16.50) POSITIVE
|
|
cnetz.c:1118 info : Received allocation 'Belegung' message.
|
|
|
|
</pre>
|
|
|
|
<p>
|
|
When the mobile phon terminates, it sends the AT message.
|
|
The base station responds with AF message and switches back to control channel.
|
|
</p>
|
|
|
|
<pre>
|
|
|
|
telegramm.c:1486 info : RX Level: 97% Jitter: 0.06 Sync Time: 11880.01 (TS 30.00) POSITIVE
|
|
cnetz.c:1286 info : Received supervisory frame 'Verbindung halten' message.
|
|
cnetz.c:1238 info : Sending 'Quittung Verbindung halten' on traffic channel
|
|
telegramm.c:1486 info : RX Level: 97% Jitter: 0.06 Sync Time: 2375.99 (TS 6.00) POSITIVE
|
|
cnetz.c:1297 info : Received release frame 'Ausloesen durch FuTln' message.
|
|
transaction.c:208 info : Transaction state VHQ -> AT
|
|
call.c:744 info : Call has been released with cause=16
|
|
cnetz.c:1253 info : Sending 'Auslosen durch FuTln' on traffic channel
|
|
database.c:124 info : Subscriber '6,2,15784' idle now.
|
|
transaction.c:89 info : Destroying transaction for subscriber '6215784'
|
|
transaction.c:208 info : Transaction state AT -> IDLE
|
|
cnetz.c:274 info : Entering IDLE state on channel 131.
|
|
telegramm.c:1486 info : RX Level: 96% Jitter: 0.06 Sync Time: 5543.98 (TS 14.00) POSITIVE
|
|
dsp.c:641 info : Switching channel (mode)
|
|
telegramm.c:1484 info : RX Level: 97% Jitter: 0.08 Sync Time: 9333.99 (TS 23.57) Bit errors: 6 POSITIVE
|
|
telegramm.c:1525 notice : Received Telegramm that is not used OgK channel signalling, ignoring! (opcode 22 = AT(V))
|
|
|
|
</pre>
|
|
|
|
|
|
[<a href="index.html">Back to main page</a>]
|
|
</td></tr></table></center>
|
|
</body>
|
|
</html>
|