User's Manual

SATELLINE-M3-TR1
User Guide, Version 3.0
27
5.7.7 Latency
In the PCC Transparent protocol mode (Option 1 and Option 2) the whole message is first read
from the serial port and after that it will be framed and transmitted over the radio.
The end of the message is detected when there is a pause in data coming from the serial port.
The symbol rates for the Pacific Crest 4FSK (Option1) are:
o 19200 bps on 25 kHz channel
o 9600 bps on 12.5 kHz channel
The symbol rates for the Pacific Crest GMSK (Option2) are:
o 9600 bps on 25 kHz channel
o 4800 bps on 12.5 kHz channel
The actual raw data rate is appr. 2/3 of the symbol rate.
5.7.7.1 Transmission delays using Option 1 (Pacific Crest 4FSK) on 25 kHz channel
The table below presents the typical latency vs. the size of the message. The delays are
measured from the end of transmitted data to the end of received data on the serial interface.
Number of bytes sent
Bps
1
10
100
500
1200
77 ms
159 ms
971 ms
4590 ms
4800
48 ms
68 ms
317 ms
1438 ms
9600
43 ms
52 ms
209 ms
912 ms
19200
40 ms
45 ms
154 ms
650 ms
38400
39 ms
41 ms
127 ms
519 ms
5.7.7.2 Transmission delays using Option 2 (Pacific Crest GMSK) on 25 kHz channel
The table below presents the typical latency vs. the size of the message. The delays are
measured from the end of transmitted data to the end of received data on the serial interface.
Number of bytes sent
Bps
1
10
100
500
1200
86 ms
168 ms
1042 ms
4949 ms
4800
57 ms
77 ms
390 ms
1796 ms
9600
52 ms
62 ms
281 ms
1272 ms
19200
50 ms
55 ms
226 ms
1009 ms
38400
48 ms
51 ms
198 ms
878 ms