I-Call?

[oldzy]

Listening in ID Scan Mode in Hamilton on my 796D, an Activity ID popped up, and that ID is not listed in the RR dbase.

When I Held on it, it sounded like someone was calling someone on the telephone and the other line answered. It was obviously Police related. The Motorola ID's at the top switched between 2 diff ones constantly. I could also hear both parties very clearly.

Jus wondering if this an I-Call? A radio calling someone on the phone... is that what is happening? Thx.

 

[richster]

Sounds like you were listening to a weird phone patch. Sounds like a constable on a portable called another contable on another portable, thats why you got the 2-switching RID's (radio-ID's). Actually I never knew portables were able to receive incomming calls and that they can only dial out, but it's the only thing I can think of. Phone patches are very common on trunking systems but are usually done to contact people outside the trunking system, not to cantact another person within the system. Phone patches would not be listed in the database because the ID you see is the RID or radio-ID not an actual TG (talkgroup). I beleive the 796D treats the phone patch pretty well like an I-call, except it doesn't jump frequencies because the transmission doesn't deykey until the phone call is done. Here our police department account for 90% of all phone patches done on our Motorola Astro typeII system. Eventhough police comms out here are digitally encrypted, their phone patches are "in the clear", must be a short-coming of the motorola system.

I use trunker to follow these types of calls with my 245xlt (246T coming soon). I do not have experience with the trunktracker 3's or greater in how the scanner interperets a phone patch. I would imagine it would treat it exactly like an I-call.

Regards,
Richster.

 

[RBerezowski]

Yes Oldzy, that's definitely an I-Call you heard. In this case, the individual call was a phone interconnect call. Why the id sometimes flips back and forth between two ids is a mystery to me. I've seen it before on the ASTRO system here, but I don't know why it happens. DEMO88/Trunker only report the Radio id, so I don't know what the scanner is seeing. Perhaps the scanner is decoding the sub-audible data on the voice channel, and seeing something there?

As for the Regina system, I believe you can set up Motorola trunked systems to provide encrypted phone interconnect calls. However, it was not done here. Possibly that was to allow the other departments to also use the same interconnect, and since the other departments are analog users the phone interconnect has to be analog? Perhaps you can't have analog and encrypted digital interconnects on a system, it's a choice of one or the other? I'm not certain.

And yes, it is possible to dial into a trunked system to a radio. Basically you dial the telephone access number for the system from a landline, and when the system answers you enter the radio id for the radio you want to call. Then, assuming the radio is turned on, that radio will begin to "ring". Once the user answers, the interconnect call begins.

Rob