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diff --git a/docs/amps-cells.jpg b/docs/amps-cells.jpg Binary files differnew file mode 100644 index 0000000..a5e6b72 --- /dev/null +++ b/docs/amps-cells.jpg diff --git a/docs/focc.png b/docs/amps-focc.png Binary files differindex 4adc70f..4adc70f 100644 --- a/docs/focc.png +++ b/docs/amps-focc.png diff --git a/docs/amps-fvc.png b/docs/amps-fvc.png Binary files differnew file mode 100644 index 0000000..0cc048b --- /dev/null +++ b/docs/amps-fvc.png diff --git a/docs/amps-recc.png b/docs/amps-recc.png Binary files differnew file mode 100644 index 0000000..ba44600 --- /dev/null +++ b/docs/amps-recc.png diff --git a/docs/amps-words.png b/docs/amps-words.png Binary files differnew file mode 100644 index 0000000..e04d15d --- /dev/null +++ b/docs/amps-words.png diff --git a/docs/amps.html b/docs/amps.html index a381820..e1bc88c 100644 --- a/docs/amps.html +++ b/docs/amps.html @@ -10,8 +10,6 @@ <center><img src="amps.jpg"/></center> -<center><h1>*this doc is under construction*</h1></center> - <ul> <li><a href="#history">History</a> <li><a href="#howitworks">How it works</a> @@ -65,10 +63,28 @@ How it works <p> The detailed communication between base station and mobile station is described in <a href="TIA_EIA_553_A.compressed.pdf">TIA/EIA-553 standard</a>. Click for reading the PDF file. -Thanx to TIA for allowing me to add the standard document to this project's documentation. +Thanks to TIA for allowing me to add the standard document to this project's documentation. <i>Reproduced under written permission from Telecommunications Industry Association.</i> </p> +<center><img src="amps-cells.jpg"/></center> + +<p> +The idea a cellular network was to use clusters to re-use frequencies more ofter, so more calls can be made in one area. +As depicted, in a cluster with 7 cells (A to G), all cells must use different frequencies. +All frequencies can be re-used in surrounding clusters. +In the example, the G cell can use channel 4, 5 and 6 again in all other clusters, because their distance is far enough. +As depicted, the distance is 4.6 times the radius of a cell coverage. +To increase the number of calls using the same number of channels, the size of the cells have to be reduced. +Because cells getting smaller, hand-off is required when moving from one cell area to another. +A phone in a smaller cell must transmit with lower power than in large cells. +To keep track in which cell the phone currently located, a registration process tells the mobile switching office (MSO) where the phone can be reached in case of an incoming call. +</p> + +<p> +<font color="red">Registering, power control and handoff are the key features of a cellular network.</font> +</p> + <p> An AMPS network is divided into two systems, System A and System B. Both systems have different radio channels. @@ -93,37 +109,52 @@ A radio noise floor of 10% would be reduced to 1% by the expander. </p> <p> -Amps system was the first cellular system. -By reducing cell size, the frequencies can be reused in lower distances, so more calls can be made in an area with the same amount of channels. -Different cell sizes require a control of the tranmission power of the phone and the base station. -A system with small cells must handoff (handover) the call to another cell, if a subscriber moves outside the coverage area. -In order to know where a phone can be reached, it must register to a new cell (area), if it moves. -A database keeps track of the current location of the mobile phone. +The signaling is done with Manchester Code. +The symbol rate is 10,000 Hz, resulting in a frequency of 10 KHz. +To allow such high frequencies, the carrier frequency is directly shifted, instead of modulating two alternating tones. </p> -<p> -<font color="red">Registering, power control and handoff are the key features of a cellular network.</font> -</p> +<center><img src="amps-focc.png"/></center> <p> +As depicted, each frame that is sent on the control channel of a base station, +starts with a dotting sequence (1010101...) to sync the receiver +and a sync word (11100010010) to indicate start of message. +Two words of 40 bits are repeated 5 times for redundancy. +An A-word belongs to mobiles with the last significant bit of their mobile identification number equals '1' and a B-word to mobiles with the last significant bit of their mobile identification number equals '0'. +Around sync and dotting and after every 10 bits of a message a B/I-bit is inserted, to indicate if the control channel is busy or not. +During an incoming message from a mobile phone, the base station will block the channels by setting the B/I-bit, so other mobile phone must wait until the channel is marked free again. +The bad news is, that the base station must react in less than 5 milliseconds, which is too fast for Osmocom-Analog. +The good news is, that this feature can be turned off. </p> -<p> -</p> +<center><img src="amps-words.png"/></center> <p> +This example shows two words that are used to call a mobile phone. +Each word consists of different bits, except for the last 12 bits. +They are used for parity check, resulting in 28 usable bit for the message itself. +Other words are used to broadcast cell info of the base station. </p> -<p> -</p> +<center><img src="amps-recc.png"/></center> <p> +The other direction is similar, but the size of the messages are different. +After dotting sequence and sync word, a digital color code (DCC) is used to prevent cells in surrounding clusters to receive the message from the mobile phone. +The size of each word is 48 bits. +These include the 36-bits-message and the 12 parity bits. </p> +<center><img src="amps-fvc.png"/></center> + <p> +On a voice channel, the messages have even more redundancy, by repeating them 11 times. </p> <p> +Describing all messages with their function and their content is beyond the scope of this introduction. +Refer to the TIA specification, described above. </p> <p class="toppic"> @@ -166,7 +197,7 @@ The transmitter will now shift frequency according the the level of the sound ca In my case, my sound card is connected to a transmitter, where a positive sample value causes a negative frequency deviation. This is why I need to flip the polarity of the signal, so I generate a negative sample value that causes a positive frequency deviation. I use the '-F yes' option or '--flip-polarity yes'. -Also it is essential to use a transmitter with direct access to the modulator and and a receiver with direct access to the disciminator. +Also it is essential to use a transmitter with direct access to the modulator and and a receiver with direct access to the discriiminator. I use '-p -d' or '--pre-emphasis --de-emphasis' to process emphasis for audio signal in software. I use the calling channel (control channel) 334, which could also be used as traffic channel (voice channel). </p> @@ -181,85 +212,168 @@ Selected System ID (SID) 40 belongs to: San Jose, CA (GTE Mobile) San Rosa, CA (GTE Mobile) Santa Barbara, CA (GTE Mobile) -amps.c:390 notice : You selected 'combined control & paging & voice channel'. +amps.c:531 notice : You selected 'combined control & paging & voice channel'. This is a hack, but the only way to use control channel and voice channel on one transceiver. - Some phones may reject this. -amps.c:481 info : Entering IDLE state, sending Overhead/Filler frames on combined control & paging - & voice channel. -Base station on channel 334 ready, please tune transmitter to 880.020 MHz and receiver to 835.020 MHz. -frame.c:3658 info : RX Level: 54% Quality: 66% Polarity: NEGATIVE -frame.c:3658 info : RX Level: 53% Quality: 65% Polarity: NEGATIVE -frame.c:3658 info : RX Level: 52% Quality: 60% Polarity: NEGATIVE +Some phones may reject this, but all my phones don't. +amps.c:632 info : Entering IDLE state, sending Overhead/Filler frames on combined control & paging +& voice channel. +dsp.c:909 info : Change mode to FOCC +amps.c:585 notice : Created channel #334 (System B) of type 'CC/PC/VC' = combined control & paging +& voice channel +Base station on channel 334 ready (combined control & paging & voice channel), +please tune transmitter to 880.020 MHz and receiver to 835.020 MHz. + +</pre> + +<pre> + +# tacs -k 323 -F yes -p -d +... +Selected Area ID (AID) 3600 belongs to: + CellNet, United Kingdom +amps.c:531 notice : You selected 'combined control & paging & voice channel'. +This is a hack, but the only way to use control channel and voice channel on one transceiver. +Some phones may reject this, but all my phones don't. +amps.c:632 info : Entering IDLE state, sending Overhead/Filler frames on combined control & paging +& voice channel. +dsp.c:909 info : Change mode to FOCC +amps.c:585 notice : Created channel #323 (System B) of type 'CC/PC/VC' = combined control & paging +& voice channel +Base station on channel 323 ready (combined control & paging & voice channel), +please tune transmitter to 943.0625 MHz and receiver to 898.0625 MHz. </pre> <p> You should tune the receiver to 880.020 first, to check if you can hear and decode the idle signal from the base station. -Then tune to actually uplink frequency 835.020 MHz. +Then tune to actually up-link frequency 835.020 MHz. The actual level is not yet relevant. (You may check the quality using '-l 2' or '--loopback 2' command line option and build a radio loop by tuning the receiver to the transmitter.) </p> <p> If the polarity is correct and the volume of the signal (frequency deviation) is about right, you will make the phone register. -The phone will transmit on the uplink. +The phone will transmit on the up-link. If not, try other polarity. +Also check if the phone allows to register on the selected system (A or B) and allowed to roam (any SID/AID). This is how my phone registers to my network: </p> <pre> -frame.c:3630 info : RX RECC: DCC=0 -frame.c:2990 info : Received: Word A - Abbreviated Address Word -frame.c:2990 info : Received: Word B - Extended Address Word -frame.c:2990 info : Received: Word C - Serial Number Word -amps.c:635 info : Registration 617XXXXXXX (ESN = 825b5f79, Class 6 / Discontinuous / 25 MHz) -transaction.c:175 info : Transaction state IDLE -> REGISTER ACK -transaction.c:98 info : Created transaction '617XXXXXXX' for subscriber 'REGISTER ACK' -amps.c:989 info : Sending Register acknowledge -transaction.c:175 info : Transaction state REGISTER ACK -> REGISTER ACK SEND -frame.c:2691 info : Transmit: Word 1 - Abbreviated Address Word -frame.c:2691 info : Transmit: Word 2 - Extended Address Word (SCC == 11) -frame.c:2691 info : Transmit: Word 1 - Abbreviated Address Word -frame.c:2691 info : Transmit: Word 2 - Extended Address Word (SCC == 11) -frame.c:2691 info : Transmit: Word 1 - Abbreviated Address Word -frame.c:2691 info : Transmit: Word 2 - Extended Address Word (SCC == 11) -transaction.c:117 info : Destroying transaction for subscriber '617XXXXXXX' -transaction.c:175 info : Transaction state REGISTER ACK SEND -> IDLE +frame.c:3711 info : RX Level: 93% Quality: 99% Polarity: POSITIVE +frame.c:3680 info : RX RECC: DCC=0 (5 of 5 CRCs are ok) +frame.c:3059 info : Received: Word A - Abbreviated Address Word +frame.c:3322 info : expecting 2 more word(s) to come +frame.c:3688 info : RX RECC: (5 of 5 CRCs are ok) +frame.c:3059 info : Received: Word B - Extended Address Word +frame.c:3322 info : expecting 1 more word(s) to come +frame.c:3688 info : RX RECC: (5 of 5 CRCs are ok) +frame.c:3059 info : Received: Word C - Serial Number Word +frame.c:3322 info : expecting 0 more word(s) to come +amps.c:793 info : Registration 617XXXXXXX (ESN = 8a376086, Class 1 / Continuous / 25 MHz, TIA/EIA-553 +or IS-54A mobile station) +amps.c:799 info : -> Home country: USA +amps.c:801 info : -> Home number: 617XXXXXXX +transaction.c:245 info : Transaction state IDLE -> REGISTER ACK +transaction.c:150 info : Created transaction for subscriber '617XXXXXXX' +amps.c:1142 info : Sending Register acknowledge +transaction.c:245 info : Transaction state REGISTER ACK -> REGISTER ACK SEND +frame.c:2739 info : Transmit: Word 1 - Abbreviated Address Word +frame.c:2739 info : Transmit: Word 2 - Extended Address Word (SCC == 11) +frame.c:2739 info : Transmit: Word 1 - Abbreviated Address Word +frame.c:2739 info : Transmit: Word 2 - Extended Address Word (SCC == 11) +frame.c:2739 info : Transmit: Word 1 - Abbreviated Address Word +frame.c:2739 info : Transmit: Word 2 - Extended Address Word (SCC == 11) +transaction.c:163 info : Destroying transaction for subscriber '617XXXXXXX' +transaction.c:245 info : Transaction state REGISTER ACK SEND -> IDLE + </pre> +<p> +After some time (several minutes), the phone re-registers, because a counter in the broadcast message is incremented. +This allows the mobile switching office (MSO) to check if the phone is still available. +Changing the SID will cause the phone to register instantaneously. +</p> + +<p> +Level adjustment: +We see a receive level of around 93%. +This is already good, since I did the adjustment previously. +Tune your receiver to the up-link frequency, so you get loop-back of base station broadcast. +Run the software with "-l 2" option, so it will decode its own broadcast, if looped back through radios. +Use the variable resistor (connecting your transmitter) to adjust the volume until the received level matches the same level of your previously received message. +In my case I adjust the transmitter to match around 93%. (+- 10% is good) +Now, whatever frequency deviation the phone transmits for signaling, so does your transmitter. +Use the other variable resistor (connecting your receiver) to adjust the volume until the level matches about 100%. (+- 10% is good) +Switch back the receiver to up-link frequency and restart the phone. +</p> + +<p> +To make a call from the mobile phone to the base station, just enter some digits at the mobile phone and press the dial button. +The phone requests an outgoing call on the reverse control channel (RECC), including identity and called number. +The base station will send an assignment to the mobile station on forward control channel (FOCC). +Then phone an base station switch to the voice channel. +In this case we have only defined one channel, so the control channel becomes a voice channel for the duration of the call. +All other phones will loose coverage during the call. +</p> + <pre> -frame.c:3630 info : RX RECC: DCC=0 -frame.c:2990 info : Received: Word A - Abbreviated Address Word -frame.c:2990 info : Received: Word B - Extended Address Word -frame.c:2990 info : Received: Word C - Serial Number Word -frame.c:2990 info : Received: Word D - First Word of the Called-Address (Origination - Voice Service) -amps.c:653 info : Call 617XXXXXXX -> 5551212 (ESN = 825b5f79, Class 6 / Discontinuous / 25 MHz) -transaction.c:175 info : Transaction state IDLE -> CALL ASSIGN MOBILE ORIGINAT ING -transaction.c:98 info : Created transaction '617XXXXXXX' for subscriber 'CALLASSIGN MOBILE ORIGINATING' -amps.c:1003 info : Assigning channel to call from mobile station -transaction.c:175 info : Transaction state CALL ASSIGN MOBILE ORIGINATING -> -CALL ASSIGN MOBILE ORIGINATING SEND -frame.c:2691 info : Transmit: Word 1 - Abbreviated Address Word -frame.c:2691 info : Transmit: Word 2 - Extended Address Word (SCC != 11) -frame.c:2691 info : Transmit: Word 1 - Abbreviated Address Word -frame.c:2691 info : Transmit: Word 2 - Extended Address Word (SCC != 11) -frame.c:2691 info : Transmit: Word 1 - Abbreviated Address Word -frame.c:2691 info : Transmit: Word 2 - Extended Address Word (SCC != 11) -transaction.c:175 info : Transaction state CALL ASSIGN MOBILE ORIGINATING SEND -> CALL -amps.c:951 info : Staying on combined control + voice channel 334 -amps.c:959 info : Setup call to network. -call.c:590 info : Incoming call from '617XXXXXXX' to '5551212' -dsp.c:678 notice : SAT level 72.31% quality 98%p) -dsp.c:678 notice : SAT level 78.63% quality 100%) -dsp.c:678 notice : SAT level 78.76% quality 100%) -amps.c:585 info : Detected SAT signal with quality=100. -dsp.c:678 notice : SAT level 78.66% quality 100%) +frame.c:3711 info : RX Level: 91% Quality: 96% Polarity: POSITIVE +frame.c:3680 info : RX RECC: DCC=0 (5 of 5 CRCs are ok) +frame.c:3059 info : Received: Word A - Abbreviated Address Word +frame.c:3322 info : expecting 3 more word(s) to come +frame.c:3688 info : RX RECC: (5 of 5 CRCs are ok) +frame.c:3059 info : Received: Word B - Extended Address Word +frame.c:3322 info : expecting 2 more word(s) to come +frame.c:3688 info : RX RECC: (5 of 5 CRCs are ok) +frame.c:3059 info : Received: Word C - Serial Number Word +frame.c:3322 info : expecting 1 more word(s) to come +frame.c:3688 info : RX RECC: (5 of 5 CRCs are ok) +frame.c:3059 info : Received: Word D - First Word of the Called-Address (Origination - Voice Service) +frame.c:3322 info : expecting 0 more word(s) to come +amps.c:816 info : Call 617XXXXXXX -> 9200 (ESN = 8a376086, Class 1 / Continuous / 25 MHz, TIA/EIA-553 +or IS-54A mobile station) +transaction.c:245 info : Transaction state IDLE -> CALL ASSIGN MOBILE ORIGINATING +transaction.c:150 info : Created transaction for subscriber '617XXXXXXX' +amps.c:1156 info : Assigning channel to call from mobile station +transaction.c:245 info : Transaction state CALL ASSIGN MOBILE ORIGINATING -> CALL ASSIGN MOBILE ORIGINATING SEND +frame.c:2739 info : Transmit: Word 1 - Abbreviated Address Word +frame.c:2739 info : Transmit: Word 2 - Extended Address Word (SCC != 11) +frame.c:2739 info : Transmit: Word 1 - Abbreviated Address Word +frame.c:2739 info : Transmit: Word 2 - Extended Address Word (SCC != 11) +frame.c:2739 info : Transmit: Word 1 - Abbreviated Address Word +frame.c:2739 info : Transmit: Word 2 - Extended Address Word (SCC != 11) +amps.c:1104 info : Staying on combined control + voice channel 334 +amps.c:1109 info : Setup call to network. +call.c:765 info : Incoming call from '617XXXXXXX' to '9200' +call.c:790 info : Sending MNCC call towards Network +amps.c:1162 info : Assignment complete, voice connected +transaction.c:245 info : Transaction state CALL ASSIGN MOBILE ORIGINATING SEND -> CALL +dsp.c:915 info : Change mode from FOCC to FVC +dsp.c:762 notice : SAT level 101.56% quality 96% +dsp.c:762 notice : SAT level 100.97% quality 97% +dsp.c:762 notice : SAT level 102.29% quality 96% +dsp.c:762 notice : SAT level 102.31% quality 96% +dsp.c:762 notice : SAT level 102.00% quality 96% +amps.c:739 info : Detected SAT signal with quality=96. +dsp.c:762 notice : SAT level 102.04% quality 96% +dsp.c:762 notice : SAT level 102.26% quality 96% </pre> +<p> +The SAT shows us that the level of the voice channel is right. +If a second transceiver for voice channel is used, adjust receiver to receive sat 100% (+- 10). +Then switch the receiver to the transmitter frequency and adjust transmitted SAT level to 100% (+-10. +</p> + +<p> +If the mobile station hangs up, the phone transmits a signaling tone of 10 KHz: +</p> + <pre> amps.c:525 info : Detected Signaling Tone with quality=100. @@ -271,60 +385,84 @@ amps.c:481 info : Entering IDLE state, sending Overhead/Filler frames on combi </pre> +<p> +The make a call to the phone, enter the number and press 'd' to dial. +The base station will page the mobile phone on forward control channel (FOCC). +The mobile phone will identify itself on the reverse control channel (RECC). +The base station will send an assignment to the mobile station on forward control channel. +Then phone an base station switch to the voice channel. +The base station sends rinign order message on the forward voice channel (FVC) to make the phone ring. +The mobile station will send signaling tone on reverse voice channel (RVC) to indicate that it has not been answered yet. +</p> + <pre> -call.c:457 info : Outgoing call to 617XXXXXXX -amps.c:753 info : Call to mobile station, paging station id '617XXXXXXX' -transaction.c:175 info : Transaction state IDLE -> PAGE -transaction.c:98 info : Created transaction '617XXXXXXX' for subscriber 'PAGE' -amps.c:1025 info : Paging the phone -transaction.c:175 info : Transaction state PAGE -> PAGE SEND -frame.c:2691 info : Transmit: Word 1 - Abbreviated Address Word -frame.c:2691 info : Transmit: Word 2 - Extended Address Word (SCC == 11) -frame.c:2691 info : Transmit: Word 1 - Abbreviated Address Word -frame.c:2691 info : Transmit: Word 2 - Extended Address Word (SCC == 11) -frame.c:2691 info : Transmit: Word 1 - Abbreviated Address Word -frame.c:2691 info : Transmit: Word 2 - Extended Address Word (SCC == 11) -transaction.c:175 info : Transaction state PAGE SEND -> PAGE REPLY -frame.c:3658 info : RX Level: 60% Quality: 90% Polarity: POSITIVE -frame.c:3630 info : RX RECC: DCC=0 -frame.c:2990 info : Received: Word A - Abbreviated Address Word -frame.c:2990 info : Received: Word B - Extended Address Word -frame.c:2990 info : Received: Word C - Serial Number Word -amps.c:655 info : Paging reply 617XXXXXXX (ESN = 825b5f79, Class 6 / Discontinuous / 25 MHz) -transaction.c:175 info : Transaction state PAGE REPLY -> CALL ASSIGN MOBILE TERMINATING -amps.c:1012 info : Assigning channel to call to mobile station -transaction.c:175 info : Transaction state CALL ASSIGN MOBILE TERMINATING -> -CALL ASSIGN MOBILE TERMINATING SEND -frame.c:2691 info : Transmit: Word 1 - Abbreviated Address Word -frame.c:2691 info : Transmit: Word 2 - Extended Address Word (SCC != 11) -frame.c:2691 info : Transmit: Word 1 - Abbreviated Address Word -frame.c:2691 info : Transmit: Word 2 - Extended Address Word (SCC != 11) -frame.c:2691 info : Transmit: Word 1 - Abbreviated Address Word -frame.c:2691 info : Transmit: Word 2 - Extended Address Word (SCC != 11) -transaction.c:175 info : Transaction state CALL ASSIGN MOBILE TERMINATING SEND -> -CALL ALERT MOBILE TERMINATING -amps.c:951 info : Staying on combined control + voice channel 334 -frame.c:2691 info : Transmit: Mobile Station Control Message Word 1 (SCC == 11) -dsp.c:678 notice : SAT level 76.43% quality 98% -frame.c:2691 info : Transmit: Mobile Station Control Message Word 1 (SCC == 11) -dsp.c:678 notice : SAT level 77.44% quality 99% -frame.c:2691 info : Transmit: Mobile Station Control Message Word 1 (SCC == 11) -dsp.c:678 notice : SAT level 78.58% quality 99% -amps.c:585 info : Detected SAT signal with quality=99. -frame.c:2691 info : Transmit: Mobile Station Control Message Word 1 (SCC == 11) -dsp.c:678 notice : SAT level 79.75% quality 100% -amps.c:525 info : Detected Signaling Tone with quality=100. -call.c:646 info : Call is alerting -transaction.c:175 info : Transaction state CALL ALERT MOBILE TERMINATING -> -CALL ALERT MOBILE TERMINATING SEND -dsp.c:678 notice : SAT level 67.88% quality 98% -dsp.c:678 notice : SAT level 80.28% quality 99% -dsp.c:678 notice : SAT level 80.39% quality 99% -dsp.c:678 notice : SAT level 80.08% quality 100% +call.c:594 info : Outgoing call to 617XXXXXXX +amps.c:929 info : Call to mobile station, paging station id '617XXXXXXX' +transaction.c:245 info : Transaction state IDLE -> PAGE +transaction.c:150 info : Created transaction for subscriber '617XXXXXXX' +amps.c:1184 info : Paging the phone +transaction.c:245 info : Transaction state PAGE -> PAGE SEND +frame.c:2739 info : Transmit: Word 1 - Abbreviated Address Word +frame.c:2739 info : Transmit: Word 2 - Extended Address Word (SCC == 11) +frame.c:2739 info : Transmit: Word 1 - Abbreviated Address Word +frame.c:2739 info : Transmit: Word 2 - Extended Address Word (SCC == 11) +frame.c:2739 info : Transmit: Word 1 - Abbreviated Address Word +frame.c:2739 info : Transmit: Word 2 - Extended Address Word (SCC == 11) +transaction.c:245 info : Transaction state PAGE SEND -> PAGE REPLY +frame.c:3711 info : RX Level: 90% Quality: 95% Polarity: POSITIVE +frame.c:3680 info : RX RECC: DCC=0 (5 of 5 CRCs are ok) +frame.c:3059 info : Received: Word A - Abbreviated Address Word +frame.c:3322 info : expecting 2 more word(s) to come +frame.c:3688 info : RX RECC: (5 of 5 CRCs are ok) +frame.c:3059 info : Received: Word B - Extended Address Word +frame.c:3322 info : expecting 1 more word(s) to come +frame.c:3688 info : RX RECC: (5 of 5 CRCs are ok) +frame.c:3059 info : Received: Word C - Serial Number Word +frame.c:3322 info : expecting 0 more word(s) to come +amps.c:814 info : Paging reply 617XXXXXXX (ESN = 8a376086, Class 1 / Continuous / 25 MHz, TIA/EIA-553 +or IS-54A mobile station) +transaction.c:245 info : Transaction state PAGE REPLY -> CALL ASSIGN MOBILE TERMINATING +amps.c:1168 info : Assigning channel to call to mobile station +transaction.c:245 info : Transaction state CALL ASSIGN MOBILE TERMINATING -> CALL ASSIGN MOBILE TERMINATING SEND +frame.c:2739 info : Transmit: Word 1 - Abbreviated Address Word +frame.c:2739 info : Transmit: Word 2 - Extended Address Word (SCC != 11) +frame.c:2739 info : Transmit: Word 1 - Abbreviated Address Word +frame.c:2739 info : Transmit: Word 2 - Extended Address Word (SCC != 11) +frame.c:2739 info : Transmit: Word 1 - Abbreviated Address Word +frame.c:2739 info : Transmit: Word 2 - Extended Address Word (SCC != 11) +amps.c:1104 info : Staying on combined control + voice channel 334 +amps.c:1174 info : Assignment complete, next: sending alerting on VC +transaction.c:245 info : Transaction state CALL ASSIGN MOBILE TERMINATING SEND -> CALL ALERT MOBILE TERMINATING +dsp.c:915 info : Change mode from FOCC to FVC +amps.c:1216 info : Sending alerting +frame.c:2739 info : Transmit: Mobile Station Control Message Word 1 (SCC == 11) +dsp.c:762 notice : SAT level 101.24% quality 98% +dsp.c:762 notice : SAT level 101.47% quality 95% +amps.c:1216 info : Sending alerting +frame.c:2739 info : Transmit: Mobile Station Control Message Word 1 (SCC == 11) +dsp.c:762 notice : SAT level 98.32% quality 95% +dsp.c:762 notice : SAT level 95.59% quality 97% +amps.c:1216 info : Sending alerting +frame.c:2739 info : Transmit: Mobile Station Control Message Word 1 (SCC == 11) +dsp.c:762 notice : SAT level 96.94% quality 98% +amps.c:739 info : Detected SAT signal with quality=98. +dsp.c:762 notice : SAT level 95.97% quality 97% +amps.c:1216 info : Sending alerting +frame.c:2739 info : Transmit: Mobile Station Control Message Word 1 (SCC == 11) +dsp.c:762 notice : SAT level 96.28% quality 95% +dsp.c:762 notice : SAT level 95.89% quality 95% +amps.c:679 info : Detected Signaling Tone with quality=99. +call.c:830 info : Call is alerting +transaction.c:245 info : Transaction state CALL ALERT MOBILE TERMINATING -> CALL ALERT MOBILE TERMINATING SEND </pre> +<p> +The phone sends a signaling tone while it is ringing. +If the user answers, the phone stops signaling tone. +</p> + <pre> mps.c:527 info : Lost Signaling Tone signal @@ -333,24 +471,30 @@ transaction.c:175 info : Transaction state CALL ALERT MOBILE TERMINATING SEND </pre> +<p> +If the base station hangs up, it sends a release message on forward voice channel (FVC). +To hangup, press 'h'. +</p> + <pre> -call.c:479 info : Call hangup -amps.c:836 info : Call has been released by network, releasing call. -amps.c:866 info : Call control releases on voice channel, releasing towards mobile station. -transaction.c:175 info : Transaction state CALL -> CALL RELEASE -amps.c:1048 info : Releasing call to mobile station -transaction.c:175 info : Transaction state CALL RELEASE -> CALL RELEASE SEND -frame.c:2691 info : Transmit: Mobile Station Control Message Word 1 (SCC == 11) -dsp.c:678 notice : SAT level 76.60% quality 100% -transaction.c:117 info : Destroying transaction for subscriber '617XXXXXXX' -transaction.c:175 info : Transaction state CALL RELEASE SEND -> IDLE -amps.c:481 info : Entering IDLE state, sending Overhead/Filler frames on combined control & -paging & voice channel. +call.c:619 info : Call hangup +amps.c:999 info : Call has been released by network, releasing call. +amps.c:1019 info : Call control releases on voice channel, releasing towards mobile station. +transaction.c:245 info : Transaction state CALL -> CALL RELEASE +amps.c:1207 info : Releasing call towards mobile station +transaction.c:245 info : Transaction state CALL RELEASE -> CALL RELEASE SEND +frame.c:2739 info : Transmit: Mobile Station Control Message Word 1 (SCC == 11) +dsp.c:762 notice : SAT level 102.37% quality 96% +dsp.c:762 notice : SAT level 101.61% quality 98% +amps.c:1211 info : Release call was sent, destroying call +transaction.c:163 info : Destroying transaction for subscriber '617XXXXXXX' +transaction.c:245 info : Transaction state CALL RELEASE SEND -> IDLE +amps.c:632 info : Entering IDLE state, sending Overhead/Filler frames on combined control & paging & voice channel. +dsp.c:909 info : Change mode to FOCC </pre> - <hr><center>[<a href="index.html">Back to main page</a>]</center><hr> </td></tr></table></center> </body> diff --git a/docs/amps.jpg b/docs/amps.jpg Binary files differindex 4c2fc4c..ffc372b 100644 --- a/docs/amps.jpg +++ b/docs/amps.jpg diff --git a/docs/fvc.png b/docs/fvc.png Binary files differdeleted file mode 100644 index 3922675..0000000 --- a/docs/fvc.png +++ /dev/null diff --git a/docs/recc.png b/docs/recc.png Binary files differdeleted file mode 100644 index 750fef7..0000000 --- a/docs/recc.png +++ /dev/null diff --git a/docs/tacs.html b/docs/tacs.html index e6c15e9..5ec84c2 100644 --- a/docs/tacs.html +++ b/docs/tacs.html @@ -10,23 +10,9 @@ <center><img src="tacs.jpg"/></center> -<center><h1>*this doc is under construction*</h1></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> -*TBD* - - +Total Access Communication System (TACS) and ETACS are mostly-obsolete variants of Advanced Mobile Phone System (AMPS) which was announced as the choice for the first two UK national cellular systems in Feb 1983. +</p> <ul> <li>Frequency range base station: 935.0125 MHz - 949.9875 MHz @@ -43,19 +29,21 @@ History <li>Mobile station transmit power: 10 or 4 Watts (vehicular) 1.6 or 0.63 Watts <li>Base station transmit power: ??? (around 50 Watts) </ul> -</p> - -<p class="toppic"> -<a name="howitworks"></a> -How it works +<p> +TACS is the UK version of the AMPS. +There are three major differences: </p> -<p class="toppic"> -<a name="basestation"></a> -Setup of a base station -</p> +<ul> + <li>Different channel frequencies + <li>6,400 Hz signaling rate (instead of 8,000 Hz) + <li>Encoding of mobile station number +</ul> +<p> +Refer to <a href="amps.html">AMPS</a> documentation, but use executable 'tacs' instead of 'amps'. +</p> <hr><center>[<a href="index.html">Back to main page</a>]</center><hr> </td></tr></table></center> |
