Analog and APCO-25 Common Air Interface ?

[BOBRR]

Hello,

Have a 996, which until now, I have used only for the typical analog Mot II stuff.

Would like to try it out on digital.

Have found the following P.D. for a town near me which apparently has gone digital.
From the RR Database it shows for Lexington, MA: "Analog and APCO-25 Common Air
Interface"

So, I have the following questions, pleae:

a. If it said only "APCO-25" I would simply put in my 996 using Butel's software as
"Motorola APCO 25". Correct ? Anything else that I would have to change in the pull-downs or be aware of ?

Are CC's used with APCO 25 ?

b. Is APCO-25 the same as P-25 as far as this scanner is concerned ?

If it said P-25, how would i enter that ?

c. And I guess I should ask about it saying "Common Air Interface" ?
What does that mean, and how, if different from APCO 25 and P-25, is it handled ?

Much thanks,
B.

 

[UPMan]

a. No. You should only look at the "System Type" field in RRDB. Regardless of what it says for "System Voice" if it doesn't say "P25 Standard" as the System Type, it is not a P25 system. So, in your example above "a" the System Type is probably listed as Motorola Type II (and that is how you would program the system).

Control Channels are used on P25 trunked systems.

b. Yes.

If it said "P-25" where?

c. Common Air Interface (CAI) is standard that encompasses how voice and control signals are encoded on a channel.

 

[BOBRR]

From OP

Hi,

Just a quick thanks for the help.
Appreciate it very much.

Sure is a confusing topic, at least for me, in trying to understand
APCO 25, P 25 and how they relate.

Also, if they are both true digital, partial digital, etc. ?

And, if APCO 25 is digital, why it goes into an analog MOT II category ?

Anyway, I do appreciate the help.
Am in my 70's and I have to admit that I find this aspect confusing.

But, a great hobby, and am enjoying it.

Regards,
Bob

 

[UPMan]

P25 is a suite of standards, some parts of which can stand alone.

P25 CAI (the voice channel part) can be "overlayed" on an analog system to provide digital voice channels (and can also be used on a non-trunked frequency).

To be a P25 system, the part of the standard dealing with trunked signalling must also be implemented on the system (those are indicated in the database as P25 Standard systems).

 

[Comint]

Sure is a confusing topic, at least for me, in trying to understand
APCO 25, P 25 and how they relate.

APCO P25, APCO 25, and P25 are all ways of referring to the Association of Professional Communications Officials Incorporated, Project 25, to give it its full title.

True P25 systems (P25 Standard on RR) utilise a 9600 baud Control channel (CC). P25 CAI on Motorola systems utilise a 3600 baud CC.