Does this mean that the 64 ARFCN channels are spread across the entire spectrum (at which point channel hopping become more effective?), or just within a small allocation?
On Wed, Jul 28, 2010 at 8:22 AM, Harald Welte <[email protected]> wrote: > On Tue, Jul 27, 2010 at 09:33:07PM +0200, Sylvain Munaut wrote: > > > I don't really know if full spectrum monitoring it's required to do the > > > cracking/interception job > > > > No, it's not, unless you want to listen to _all_ the communication taking > > part simultaneously in the zone ... > > > > Most likely the local cell isn't gonna hop between all the ARFCN in the > band > > ... The two config I've seen here locally : > > - A few ARFCN relatively close together ( < 60 MHz and even often < 25 > MHz > > ) > > Yes, (I know Sylvain, you know this, but maybe not all others in this > thread) > this by the way is the result of how the spectrum is allocated to a single > operator by the regulatory authority in the respective country. > > > - The BCCH ARCFN + A large contiguous range of hopping ARFCN somewhere > > else. > > This is the result of common network planning methods where you have one > rarely > reused allocation of ARFCN for BCCHs, and faster frequency reuse scheme for > the hopping and power-controlled traffic chnannels. > > Also, you generally are interested in the traffic of one cell. And for > that > cell, you can obtain the Cell Channel Allocation list from its BCCH. After > that > you have a limited set of ARFCNs that you will have to monitor. The > specification limits the number of ARFCN of one given cell to 64. > > -- > - Harald Welte <[email protected]> > http://laforge.gnumonks.org/ > > ============================================================================ > "Privacy in residential applications is a desirable marketing option." > (ETSI EN 300 175-7 Ch. A6) > _______________________________________________ > A51 mailing list > [email protected] > http://lists.lists.reflextor.com/cgi-bin/mailman/listinfo/a51 > -- Cal Leeming Operational Security & Support Team *Out of Hours: *+44 (07534) 971120 | *Support Tickets: * [email protected] *Fax: *+44 (02476) 578987 | *Email: *[email protected] Simplicity Media Ltd. All rights reserved. Registered company number 7143564
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