work on docs

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Andreas Eversberg 2018-12-23 19:42:42 +01:00
parent e16a2dd548
commit ea5e17a036
2 changed files with 42 additions and 1 deletions

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@ -40,7 +40,9 @@ The network was closed for the exclusive benefit of the standard GSM in July 28t
<p>
<ul>
<li>Frequency range UHF: 424.800 - 427.9875 MHz (down-link); 414.800 - 417.9875 MHz (up-link)
<li>Frequency range UHF (Band 1): 424.800 - 427.9875 MHz (down-link); 414.800 - 417.9875 MHz (up-link)
<li>Frequency range VHF (Band 3): 169.800 - 172.9875 MHz (down-link); 165.200 - 168.3875 MHz (up-link)
<li>See software option "-B list" for other bands
<li>256 voice or contol channels
<li>Duplex distance: 10 MHz
<li>Channel spacing: 12.5 KHz
@ -69,6 +71,8 @@ for a description of the standard.
<p class="toppic">
<a name="basestation"></a>
Setup of a base station
<br><br>
TBD: Tested band 1 and 3 so far!
</p>
<hr><center>[<a href="index.html">Back to main page</a>]</center><hr>

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@ -349,6 +349,43 @@ Refer to NMT section about configuring an NMT network.
I highly recommend to use an SDR instead of radios connected to a sound card.
</p>
<p class="toppic">
Increase performance on ARM CPUs (Raspberry PI)
</p>
<p>
To see the CPU consumption of all threads, enter "top -H" into the shell:
</p>
<pre>
top - 14:55:31 up 1 day, 22:27, 3 users, load average: 0,75, 0,19, 0,06
Threads: 113 total, 2 running, 66 sleeping, 0 stopped, 0 zombie
%Cpu(s): 30,2 us, 2,1 sy, 0,0 ni, 55,7 id, 11,2 wa, 0,0 hi, 0,7 si, 0,0 st
KiB Mem : 949448 total, 523164 free, 134692 used, 291592 buff/cache
KiB Swap: 102396 total, 102396 free, 0 used. 751960 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
11375 root -2 0 165148 97956 4940 R 91,1 10,3 0:24.29 nmt
11391 root -2 0 165148 97956 4940 S 13,8 10,3 0:04.00 nmt-sdr_tx
11392 root -2 0 165148 97956 4940 S 13,8 10,3 0:03.91 nmt-sdr_rx
11380 root 20 0 165148 97956 4940 S 2,3 10,3 0:01.20 nmt
11390 root -2 0 165148 97956 4940 S 2,0 10,3 0:00.58 nmt
11389 root -2 0 165148 97956 4940 S 1,3 10,3 0:00.51 nmt
11441 root 20 0 10056 3544 3096 R 1,3 0,4 0:00.19 top
19768 root 20 0 10056 3272 2752 S 1,3 0,3 19:16.50 top
67 root 20 0 0 0 0 S 0,3 0,0 0:02.80 mmcqd/0
9913 root 20 0 0 0 0 I 0,3 0,0 0:00.04 kworker/u8:0
1 root 20 0 28004 5916 4788 S 0,0 0,6 0:04.68 systemd
...
</pre>
<p>
In this case I use a Raspberry PI and run NMT network with multiple channels.
It is almost at the limit, since I have around 90% CPU usage of the main thread.
It wouldn't work to have 2 transceivers at 200KHz Bandwidth without fast math approximation.
Use '--fast-math' to increase processing speed.
</p>
<hr><center>[<a href="index.html">Back to main page</a>]</center><hr>
</td></tr></table></center>
</body>