Hi, Thank you for this explanation. Best regards, Robert, On Mar 11, 2016, at 5:04 PM, Harald Welte <laforge@gnumonks.org> wrote:
Hi Robert,
On Fri, Mar 11, 2016 at 04:05:15PM +0200, robert wrote:
I would like to know what are the capabilities of the silent-call implemented in OpenBSC. When I try the command from VTY, I do not get any useful information from the target. Should it be like a normal call where I can listen to the called number but without having the target notified?
a silent call is a pure signalling connection, it does not have any actual voice data. It serves primarily the purpose of turning the MS into a permanently (on one TS) transmitting beacon that can be localized using various radio-localization techniques.
We implemented the feature in order to demonstrate/show-case some of the GSM "mis-features" that are being abused by signalling intelligence / law enforcement devices. -- - Harald Welte <laforge@gnumonks.org> http://laforge.gnumonks.org/ ============================================================================ "Privacy in residential applications is a desirable marketing option." (ETSI EN 300 175-7 Ch. A6)