<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12pt"><div class="" style="">Thanks, this is very helpful.</div><div class="" style=""><br class="" style=""></div><div class="" style="">Alex</div><pre class="" style=""><b style="font-family: 'Times New Roman'; font-size: medium; white-space: normal;" class="">Graham Cobb</b><span style="font-family: 'Times New Roman'; font-size: medium; white-space: normal;" class=""> </span><a href="mailto:ukcrypto%40chiark.greenend.org.uk?Subject=Re%3A%20Data%20retention%20question&In-Reply-To=%3C53C816D6.9050303%40cobb.uk.net%3E" title="Data retention question" style="font-family: 'Times New Roman'; font-size: 16px; white-space: normal;" class="">g+ukcrypto at cobb.uk.net </a> wrote:</pre><pre class="" style=""><span style="font-size: 12pt;" class="">> I know nothing about how the UK operators
are set up, but I know a</span></pre><pre class="" style=""><span style="font-size: 12pt;" class="">> little about billing in mobile networks in general.</span></pre><pre class="" style="">> For those operators who retain location for data use, they almost<br class="" style=""></pre><pre class="" style="">> certainly take it from the "CDR" (call detail record) which is the<br class="" style=""></pre><pre class="" style="">> notification sent to the billing system about any (potentially)<br class="" style=""></pre><pre class="" style="">> chargeable event. That is consistent with the description you reproduced.
> For voice calls, the CDR is normally only generated at the end of the<br class="" style=""></pre><pre class="" style="">> call (except for very long-lived calls -- most networks will generate a
> CDR after 24 hours if the call is still going).
</pre><div class="" style="">> [ more useful information snipped] </div><div class="" style=""><br class="" style=""></div><div class="" style=""><br class="" style=""></div><div class="" style=""><br class="" style=""></div><div class="" style=""><br class="" style=""></div></div></body></html>