we’re looking to use Krakenrf for DF of phones. for those in police/security biz may know that using IMSI catcher one can control a Tgt phone and choose to enable the phone to ‘beacon’ on a silent call. currently the DF market offerings for this purpose are somewhat limited to pre-selected earfcn channels (set frequencies used in cellular transmissions - e.g. 4G LTE frequency band ), some IMSI catchers you cannot pre-select the allocated frequency the phone will be on as it is a software selection of ‘quiet channels’ in that area. the other assumption is that krakenrf RF receive unit can be upgraded to encompass higher frequencies. (700mhz-3ghz in cellular range)
Phones only Tx at 200mW if not powered down, have no antenna gain and are often indoor. The range will be very limited for DFing.
How do you tell one phone from another when they all transmit on the same channel?
Years ago one company here kept pinging the phone of a non responsive hiker (2G) and the battery went flat quickly before authorities were in the area. For Kraken to be useful will you need continuous transmission?
In LTE how can you get the base station scheduler to allocate the same uplink PRBs every TTI so Kraken can df just that frequency?
with IMSI catcher assistance it controls specific phone and will cause the phone to transmit on a specific Band, given that Band we tune the DF to detect that transmission - within a few hundred meters only. using directional antenna can walk in that direction to increasing signal strength find source within a few metres.
we figure that using Krakenrf - assuming we can set the band (freq range) we already know the phone is transmitting on and using the multi antennas we can DF more effectively. but even using 1 Directional antenna we are in good shape for DF as we do now.
the problem we are trying to solve is that all DF we source at moment only allow for a small range of Bands to be selected, we must specify them on order. Unfortunately the Bands that are commonly in use in different countries and even Different areas of same country can vary, so we need to be able to ‘tune’ the DF receiver to the specific Band selected by the IMSI catcher.
we have even tried using spectrum analyser (Aaronia) as the DF , can select the freq ok, but the refresh rate is too slow, the operation is also over complicated for the users.
If you can force the phone to transmit on a channel that is unused, then it should be easy. But if there are time interleaved pulses on that same frequency, it will be impossible as the two signals will be seen as one by the KrakenSDR .
Secondly you’d need to force it onto a channel that can be received by the KrakenSDR which only goes up to 1766 MHz.
yes we can force a specific phone to transmit on an un-used channel.
freq over 1766 Mhz is part of the problem, often the Channel selected is anywhere in 4G range which can up to 3ghz.
perhaps there is plan to extend range of RF receiver in Krakenrf?
Yes, we are considering a separate product that with an extended frequency range, but there is no timeline for release of this product. It will also be a substantially more expensive device.