3 ms·
It need only reply if it is requested to do so, therefore for 99.9 recurring percent of the time there need be nothing observable.
by Theodores 13y ago
It need only reply if it is requested to do so, therefore for 99.9 recurring percent of the time there need be nothing observable.
- alexwright 13y agoOr reply in some side channel, piggy back the next (expected, ie when the user has switch back to normal mode) UMTS radio packet for example. I don't know the packet structure but I expect there are areas that could be re-purposed covertly. We did after all fit the entire SMS system into such a space.