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-rw-r--r--docs/amps.html17
1 files changed, 12 insertions, 5 deletions
diff --git a/docs/amps.html b/docs/amps.html
index 16d7ea0..a295482 100644
--- a/docs/amps.html
+++ b/docs/amps.html
@@ -38,7 +38,7 @@ History
<li>Duplex distance: 45 MHz
<li>Channel spacing: 30 KHz
<li>Voice modulation: FM
- <li>Signalling modulation: carrier FSK
+ <li>Signaling modulation: carrier FSK
<li>Frequency deviation: 8 KHz (FSK)
<li>Mobile station transmit power: 4 Watts (vehicular) 1.6 or 0.6 Watts
<li>Base station transmit power: ??? (around 50 Watts)
@@ -58,6 +58,13 @@ History
*TBD* SID and System A/B
</p>
+<p>
+To reduce radio noise, a syllabic compandor is used on both ends.
+This compresses the audio level dynamics by 2.
+An audio level of 25% is raised to 50% by the compressor and lowered to 25% by the expandor.
+A radio noise floor of 10% would be reduced to 1% by the expandor.
+</p>
+
<p class="toppic">
<a name="basestation"></a>
Setup of a base station
@@ -140,7 +147,7 @@ frame.c:2691 info : Transmit: Word 2 - Extended Address Word (SCC != 11)
transaction.c:175 info : Transaction state CALL ASSIGN MOBILE ORIGINATING SEND -&gt; CALL
amps.c:951 info : Staying on combined control + voice channel 334
amps.c:959 info : Setup call to network.
-call.c:590 info : Incomming call from '617XXXXXXX' to '5551212'
+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%)
@@ -151,7 +158,7 @@ dsp.c:678 notice : SAT level 78.66% quality 100%)
<pre>
-amps.c:525 info : Detected Signalling Tone with quality=100.
+amps.c:525 info : Detected Signaling Tone with quality=100.
transaction.c:117 info : Destroying transaction for subscriber '617XXXXXXX'
transaction.c:175 info : Transaction state CALL -&gt; IDLE
call.c:711 info : Call has been released with cause=16
@@ -203,7 +210,7 @@ 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 Signalling Tone with 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 -&gt;
CALL ALERT MOBILE TERMINATING SEND
@@ -216,7 +223,7 @@ dsp.c:678 notice : SAT level 80.08% quality 100%
<pre>
-mps.c:527 info : Lost Signalling Tone signal
+mps.c:527 info : Lost Signaling Tone signal
call.c:689 info : Call has been answered by '617XXXXXXX'
transaction.c:175 info : Transaction state CALL ALERT MOBILE TERMINATING SEND -&gt; CALL