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<p style="margin-top:0;margin-bottom:0">Neel, </p>
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<p style="margin-top:0;margin-bottom:0">The APDU that you are referring here is the one used with binary SMS. If so, is then we consider the SMS-PP envelope or the SMS-Deliver approach, in both the cases, we require to know the Ki, Kc and TAR for successful
execution of the command(packed in the APDU). How to predict these or any alternative to by-pass this, exists? </p>
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<p style="margin-top:0;margin-bottom:0">BR</p>
<p style="margin-top:0;margin-bottom:0">Snehasish</p>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Neels Hofmeyr <nhofmeyr@sysmocom.de><br>
<b>Sent:</b> Monday, November 5, 2018 12:46:23 AM<br>
<b>To:</b> Snehasish Kar<br>
<b>Cc:</b> openbsc@lists.osmocom.org<br>
<b>Subject:</b> Re: Help with silent call</font>
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<div class="PlainText">On Sat, Nov 03, 2018 at 12:06:33PM +0000, Snehasish Kar wrote:<br>
> I have read that silent-calls in GSM can be used to make a call to a target<br>
> MS and listen to it<br>
<br>
Not listen to it in terms of audio. You can't eavesdrop on an MS with a slient<br>
call.<br>
<br>
You *can* open a channel and receive measurement reports from it, so that you<br>
see which other cells it sees at which receive levels, and how far it is from<br>
the current cell (TA). From that you could derive its position.<br>
<br>
The silent call has been one of the earliest features in Osmocom, but until<br>
recently has been broken in osmo-msc. IIUC it is now fixed again in current<br>
master, but might not be in a release yet.<br>
<br>
There's also the APDU a.k.a. the RR App Info (I hope I got the names right),<br>
which may or may not contain GPS positioning data that the MS is sending to the<br>
core net.<br>
<br>
In both cases the owner of the MS has no explicit idea that they are sharing<br>
any details on their position.<br>
<br>
~N<br>
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