• To anyone looking to acquire commercial radio programming software:

    Please do not make requests for copies of radio programming software which is sold (or was sold) by the manufacturer for any monetary value. All requests will be deleted and a forum infraction issued. Making a request such as this is attempting to engage in software piracy and this forum cannot be involved or associated with this activity. The same goes for any private transaction via Private Message. Even if you attempt to engage in this activity in PM's we will still enforce the forum rules. Your PM's are not private and the administration has the right to read them if there's a hint to criminal activity.

    If you are having trouble legally obtaining software please state so. We do not want any hurt feelings when your vague post is mistaken for a free request. It is YOUR responsibility to properly word your request.

    To obtain Motorola software see the Sticky in the Motorola forum.

    The various other vendors often permit their dealers to sell the software online (i.e., Kenwood). Please use Google or some other search engine to find a dealer that sells the software. Typically each series or individual radio requires its own software package. Often the Kenwood software is less than $100 so don't be a cheapskate; just purchase it.

    For M/A Com/Harris/GE, etc: there are two software packages that program all current and past radios. One package is for conventional programming and the other for trunked programming. The trunked package is in upwards of $2,500. The conventional package is more reasonable though is still several hundred dollars. The benefit is you do not need multiple versions for each radio (unlike Motorola).

    This is a large and very visible forum. We cannot jeopardize the ability to provide the RadioReference services by allowing this activity to occur. Please respect this.

P25 Phase II, how to calculate base freq and offset?

Status
Not open for further replies.

ElroyJetson

I AM NOT YOUR TECH SUPPPORT.
Premium Subscriber
Joined
Sep 8, 2002
Messages
3,687
Location
DO NOT ASK ME FOR HELP PROGRAMMING YOUR RADIO. NO.
Does anyone have a method or procedure to determine the base frequency and channel spacing of a P25 Phase II TDMA system, calculating from the published frequency lists in the RR database?

An example to work with would be the Apopka, FL Phase II TRS. Why that one? Why not? Top of the
list in alphabetical order.
 

greenthumb

Colorado DB Administrator
Database Admin
Joined
Feb 29, 2004
Messages
1,942
It's a configurable parameter in most systems, so there isn't a sure-shot way to know it without having that information from pro96com or the system itself. You can usually deduce 6.25 kHz spacing on a 700 system, but the base can be different across 800 systems and can be either 6.25 kHz or 12.5 kHz and work just fine, depending on the base. For VHF or UHF systems, the spacing can be just about anything.

It really doesn't matter whether it's phase I or II - both slots refer to the same frequency...just different slots.
 

ElroyJetson

I AM NOT YOUR TECH SUPPPORT.
Premium Subscriber
Joined
Sep 8, 2002
Messages
3,687
Location
DO NOT ASK ME FOR HELP PROGRAMMING YOUR RADIO. NO.
I should expand on my earlier comments a bit. I'm not using a scanner. I'm using appropriate two way radios with appropriate features and software that are fully capable of listening in. (They will not be permitted to transmit, using every appropriate programming trick and even hardware mod necessary
in order to achieve this.)

Specifically, I'll be using a Harris (M/A-Com) P7100ip with all features, up to date firmware and DSP code, and RPM 9 to program it.

The programming of this will be slightly different than programming a scanner.

I don't have a tutorial or guide for setting up a TDMA system in RPM but exploring the software has
given me some clues.

I'm still really unclear on whether the 700 MHz channels should be treated separately from the 800 MHz channels or treated as the same group of channels.
 

greenthumb

Colorado DB Administrator
Database Admin
Joined
Feb 29, 2004
Messages
1,942
It's the same group of channels for 700 MHz and 800 MHz (in the control channel list) but a different IDEN set. A 7100 won't do P25 Phase II or 700 MHz...

The IDEN set programmed into the radio should match what is programmed into the system, which can be captured via a variety of sources (pro96com being the easiest), or it potentially won't work right. Radios should read the IDEN sets off the air, but Harris (being low QA/QC on their software) sometimes does it and sometimes does not. But really, my thoughts don't change whether this pertains to a scanner or radio. Scanners calculate the frequency the same way that a radio on the system does.

If you had a P25 Phase II capable Harris radio, you would just need to have the correct feature enabled, the TDMA box checked on the system and have the radio programmed with XGPR1 (or higher) radio code.
 

ElroyJetson

I AM NOT YOUR TECH SUPPPORT.
Premium Subscriber
Joined
Sep 8, 2002
Messages
3,687
Location
DO NOT ASK ME FOR HELP PROGRAMMING YOUR RADIO. NO.
I should SOON have a working P7200 which will do Phase II, I think, but for now I'm still going to use the 7100 to learn the rest of P25 programming.

I had (and still have) no documentation on the IDEN channel set. I'm not even sure what it is exactly, but I'm pretty sure it has nothing to do with the Motorola/Nextel iDen format.

Interestingly, RPM does allow me to choose full rate or 2 slot TDMA in the IDEN channel assignment screen, when the radio type is set to P7100. I don't think the 7100 is TDMA capable so that's kind of interesting.
 

WayneH

Forums Veteran
Super Moderator
Joined
Dec 16, 2000
Messages
7,521
Location
Your master site
You're going to need to run software like PRO96COM as you need to know the TDMA IDEN message details. Each identifier OSP includes a number to identify it from the others, which when wrong makes the radio useless as all calls reference this for proper calculation of frequency. There will be a second IDEN OSP for TDMA.

Motorola uses a manufacturer specific OSP to identify this second range for TDMA. So I'm curious how Harris will do this. Probably generate their own and also interpret Motorola's for compatibility reasons.
 

GTR8000

NY/NJ Database Guy
Database Admin
Joined
Oct 4, 2007
Messages
15,421
Location
BEE00
Motorola uses a manufacturer specific OSP to identify this second range for TDMA. So I'm curious how Harris will do this. Probably generate their own and also interpret Motorola's for compatibility reasons.

I could be wrong, but I don't believe that's the case. If it were a Motorola specific OSP, the second octet would be "90", not "00". Here is a Phase II system reporting both the FDMA and TDMA IDEN_UP messages:

Code:
3D 00 03 22 D0 32 0A 25 10 A2 63 A0 Identifier Update 0 Base 851006250 Spacing 6250 Tx Offset -45000000
3D 00 13 25 E0 32 09 15 75 62 1B 36 Identifier Update 1 Base 762006250 Spacing 6250 Tx Offset 30000000
33 00 23 38 40 64 0A 25 15 84 48 4B Identifier Update 2 Base 851012500 Spacing 12500 Tx Offset -45000000 Slots 2
33 00 33 A5 80 64 09 15 75 62 75 FC Identifier Update 3 Base 762006250 Spacing 12500 Tx Offset 30000000 Slots 2
 

GTR8000

NY/NJ Database Guy
Database Admin
Joined
Oct 4, 2007
Messages
15,421
Location
BEE00
That's interesting, though. I've got logs on a few different Moto systems, I haven't seen any $90 IDEN_UP messages for Phase II systems.

Is it possible that those are for X2-TDMA OSP's, and not Phase II? That would explain the Moto specific message.
 

GTR8000

NY/NJ Database Guy
Database Admin
Joined
Oct 4, 2007
Messages
15,421
Location
BEE00
The ones I posted were from 700 MHz Moto Phase II systems (three separate systems broadcasting the same OSP's).

I assume it's possible that an X2 system that has been upgraded to Phase II might still broadcast the same IDEN_UP OSP's. Probably in addition to the Phase II OPS's, though. I'm not certain, I have no logs from X2 systems, unfortunately.
 

WayneH

Forums Veteran
Super Moderator
Joined
Dec 16, 2000
Messages
7,521
Location
Your master site
Yeah, I'm not exactly sure yet and still learning the OSP structure and P25 CC personalities. And I don't want to take over Elroy's thread also. My first paragraph in my first post should still apply though.
 

mikewazowski

Forums Manager/Global DB Admin
Staff member
Forums Manager
Joined
Jun 26, 2001
Messages
13,462
Location
Oot and Aboot
Just checked a freshly installed Motorola P25 system near me and the IDEN_UP messages all show $00 for both FDMA and TDMA ranges.

Looks like $90 might be X2 only.
 

Jay911

Silent Key (April 15th, 2023)
Feed Provider
Joined
Feb 15, 2002
Messages
9,378
Location
Bragg Creek, Alberta
Just checked a freshly installed Motorola P25 system near me and the IDEN_UP messages all show $00 for both FDMA and TDMA ranges.

Looks like $90 might be X2 only.

This is correct from what I've seen doing my traveling and tracking. I don't remember where, but somewhere in my travels, I've had an X2 system's iden data come up on a nonstandard TSBK.
 

KevinC

Big Dog...celebrating 10 years of abuse!
Super Moderator
Joined
Jan 7, 2001
Messages
11,341
Location
Home
Mikey is correct. Also, a system can't be both X2 and Phase 2 TDMA at the same time, it's one or the other.
 

pepsima1

Completely Banned for the Greater Good
Banned
Joined
Nov 19, 2008
Messages
1,078
Location
Pimp County, Neveda
So yes I am trying to understand when reading ProCom96 too. I read this info and it really interest me.

So I used procom on a 400 mhz system which is a Moto Phase I FDMA system. I believe I am looking at the Packet Data and the second octet is reading 90. What does that mean? As well as when I am programming a radio which is not a scanner but a commerical grade radio I am looking for this line which is the updated identifier table RIGHT?

Thanks. Just trying to learn like the rest of us.
 

Attachments

  • Capture.jpg
    Capture.jpg
    53.8 KB · Views: 1,921
Status
Not open for further replies.
Top