How "Open Source" is APCO 25?

[vabiro]

Hi,

I have been trying to determine exactly how "Open Source" the P25 standard is. Specifically, is there a significant difference in how it is implemented from one manufacturer to another.

For example, if a large multi-site system were installed by Motorola how likely is it that one could switch to using Kenwood, Tait or any other radios.

The core question is, if you were a purchaser of a system like this would you be married to Motorola in the way that you would be with buying a Mac and not being able to use Windows software. (on so many levels an awkward example I know:lol

Any thoughts would be appreciated.

Cheers
Victor

 

[code3cowboy]

It depends on weather or not they use true P25 standards. If you use P25 digital voice, but couple it to a proprietary trunking method, it is not really P25 at all.
If you are using a true P25 system, any P25 radio will work (unless you have a motorola P25 "capable" radio that would require several hundred dollars in software upgrades).

 

[N_Jay]

You are confusing the Term "Open Source" with what is referred to as an "Open Standard".

Open Source refers to software code the is free for all to use and expand upon.

P25 is an Open Standard, which anyone can use providing the agree to the terms under which any "Essential Patents" have been identified.

P25 defines several interfaces, one of which is called the Common Air Interface (CAI)
Any vendor who builds product to the CAI (in the mode being used, i.e Conventional, Trunked, Secure, etc.) will interoperate.

How the software is implemented has little to do with compatibility the interface standard.

The answer to the core question is "Yes". Providing that the system is using the standard for all its functions and the subscriber unit has the same functions implemented under the standard.

 

[wlmr]

As N_Jay stated, multiple manufacturers have successfully implemented P25 trunked radios. There is room in the standard for add-on features that only the trunking system manufacturer's radios my fully work with. (Unless of course another company signs an agreement with the system manufacturer.)

Basic talk/listen functionality does come under a common standard - additional features such as dynamic regrouping are not (I think) spelled out under the standard and may not function for radios from other manufacturers.

 

[vabiro]

You are confusing the Term "Open Source" with what is referred to as an "Open Standard".

Open Source refers to software code the is free for all to use and expand upon.

Quite right.

Mia culpa.

Too much time working with software.

<SNIP>
The answer to the core question is "Yes". Providing that the system is using the standard for all its functions and the subscriber unit has the same functions implemented under the standard.

OK, so that moves me a bit closer to the answer that I would like to get at, but may not have been clear about. However, I think wlmr is thinking along the lines I am with his answer:

As N_Jay stated, multiple manufacturers have successfully implemented P25 trunked radios. There is room in the standard for add-on features that only the trunking system manufacturer's radios my fully work with. (Unless of course another company signs an agreement with the system manufacturer.)

Basic talk/listen functionality does come under a common standard - additional features such as dynamic regrouping are not (I think) spelled out under the standard and may not function for radios from other manufacturers.

I suppose the most common (in my area) implementation are Motorola Trunked P25 implementations. So that begs the question: does anyone -besides Motorola - make a radio that is interoperable with such an implementation (Motorola trunking with P25), or is that government/organisation married to the Monster from Schaumburg?

Victor

 

[wlmr]

I suppose the most common (in my area) implementation are Motorola Trunked P25 implementations. So that begs the question: does anyone -besides Motorola - make a radio that is interoperable with such an implementation (Motorola trunking with P25), or is that government/organisation married to the Monster from Schaumburg?

Victor

At least one full P25 800MHz Motorola system has Kenwood and EF Johnson radios in day to day operation right alongside Motorola radios. You are definitely not married to Motorola. Others can speak to VHF or UHF Motorola P25 systems better than I can.

 

[N0YFE]

Apco p25

At least one full P25 800MHz Motorola system has Kenwood and EF Johnson radios in day to day operation right alongside Motorola radios. You are definitely not married to Motorola. Others can speak to VHF or UHF Motorola P25 systems better than I can.

The base of that system is APCO P25.

That is a great example of a system that used consultants and engineers to design and build out the system so they were not tied to one model radio. From reading up on other systems is the lack of planning and preparing for such a huge capital expense and not insuring that the final result will meet the needs and expectations of the agency. It also doesn't hurt to have a 3rd party review the plans and designs to make sure everyone is on the right page.

 

[N_Jay]

I suppose the most common (in my area) implementation are Motorola Trunked P25 implementations. So that begs the question: does anyone -besides Motorola - make a radio that is interoperable with such an implementation (Motorola trunking with P25), or is that government/organisation married to the Monster from Schaumburg?

The issue comes from exactly what version of "Motorola" system you are discussing.

Motorola has built Smartnet systems systems that used ASTRO (non-P25) voice channels, SmartNet system systems with P25 CAI voice channels, and full P25 systems.

These have much more to do with the timing of the implementation and the requirements of the customer then some grand "Shaumbugian" conspiracy.

 

[vabiro]

The issue comes from exactly what version of "Motorola" system you are discussing.

Motorola has built Smartnet systems systems that used ASTRO (non-P25) voice channels, SmartNet system systems with P25 CAI voice channels, and full P25 systems.

That's what I thought: there is no hard and fast rule (i.e. P25=open to multiple vendors)

These have much more to do with the timing of the implementation and the requirements of the customer then some grand "Shaumbugian" conspiracy.

I am reluctant to use the term conspiracy. I think it has more to do with: as a company tries to build a product based on such a standard they discover gaps (like any open standard like IPSec, OSPF, etc.) in the standard and develop a work-around. That work-around is frequently developed into Intellectual Property that they want to monetize.

Motorola has a great product and come up with some great solutions and enhancements. Unfortunately, when they do large (and some times small) implementations they use this IP and lock out the competition as a side effect.

Fixing a problem with the tools at hand: Yes
Conspiracy: Maybe, but not so much

In some standards, any "enhancement" must be released to the community if they want to use/market as the core standard. I am curious if that is the case with P25. WiFi and Bluetooth are like this, I believe.

Cheers
Victor

 

[N_Jay]

That's what I thought: there is no hard and fast rule (i.e. P25=open to multiple vendors)

There are plenty of hard and fast rules, but not as simplistic as P25:Y/N

I am reluctant to use the term conspiracy.

That seems to put you in the minority.

I think it has more to do with: as a company tries to build a product based on such a standard they discover gaps (like any open standard like IPSec, OSPF, etc.) in the standard and develop a work-around. That work-around is frequently developed into Intellectual Property that they want to monetize.

Motorola has a great product and come up with some great solutions and enhancements. Unfortunately, when they do large (and some times small) implementations they use this IP and lock out the competition as a side effect.

True, but most of the issues that most people like to complain about are clearly traced to product and standards, development and release timing, with a heavy dose of maintaining embedded equipment.

In some standards, any "enhancement" must be released to the community if they want to use/market as the core standard. I am curious if that is the case with P25. WiFi and Bluetooth are like this, I believe.

Most standards that is not the case.
Even if required there is no assurance that the standard will pick up the enhancement.

It is not the case for P25 and I do not believe it is for WiFi.

I forget BT, as I have not been involved with those standards since about 1999.

 

[PeterGV]

@vabiro... I'm not sure you're connecting with what people have been saying. Maybe you are... Let me try to just emphasize to be sure we're all on the same page here, because people get confused by this all the time.. even when trying to program their scanners.

There are two Trunked Radio Systems that people frequently refer to as being "P25":

a) Standard Moto (for example Smartnet or Type II SmartZone) trunked radio systems (the trunking/control protocol is pure proprietary Moto), with IMBE encoded audio. P25 uses IMBE audio. So, people wind-up calling these systems "P25 systems". They're not. They're just Moto trunked systems with IMBE audio. Example: Nashua, NH.

b) Actual systems that use P25 trunking, with or without IMBE encoded audio. Example: Cobb County Georgia.

For systems like item a, above... you're wed to Moto gear.

For systems like item b, above... you have a "standards based" system where gear from different manufacturers should work together. I've read that there are now organizations that do standards compliance testing that check gear for interoperability.

Maybe you already "got" all this from other people's previous posts -- which have all been right on the money. But from your replies, I wasn't entirely sure.

Peter
K1PGV

 

[N_Jay]

"a" above uses the P25 CAI (not just IMBE) on the voice channels, but is still a proprietary system due to the Motorola control channel.
EF Johnson makes equipment for these systems also.

"b" systems use the P25 protocols on both Control and Voice channels, and are therefore open to all P24 compliant equipment.
P25 only uses IMBE (or newer compatible vocoders), so I am not sure what you meant by "with or without IMBE".