Using Personal Radio on Municipal System

[ElroyJetson]

But then there are large systems that are full time encrypted. Case in point: State of Florida SLERS system. I guess they've made some progress toward implementing the P25 system but I think that daily ops are still running on their very proprietary EDACS ESK system. It's a statewide system, and in theory every county and city level department should have access to it on interoperability channels but in practice this means that the interoperable radios must be EDACS with ESK and programmed by certain very specific vendors who handle the state system in various regions. This is problematic because most agencies use Motorola subscriber equipment. It isn't exactly convenient to have to reach for "that OTHER radio" to have interoperable communications with other agencies in your state.

Plus, the larger the system, the more likely it is to be full time encrypted. And then the logistical problems of providing the interoperable radios with up to date encryption keys can be a problem.

 

[PCPA]

I just want to clarify: I do have a radio on a normal day. It's just when the pinkhairs throw their tantrums and the bricks and bottles start flying that you run the risk of not having your own, which also happens to be the worst time for that to happen.

Copy, sir!

My mantra has always been "if I can't hear you I can't help you."

 

[Project25_MASTR]

Plus, the larger the system, the more likely it is to be full time encrypted. And then the logistical problems of providing the interoperable radios with up to date encryption keys can be a problem.

Not necessarily. GATRRS is a large system (in terms of coverage area it's actually the largest in Texas) and it's not fully encrypted (but agencies have the ability to encrypt on their talkgroups). TxWARN (which is the largest P25 system in Texas in terms of site count) isn't fully encrypted (but agencies have the ability to encrypt). TxWARN also covers the Houston metroplex which is in the top 5 largest metro areas in the country. Then you have the DFW metroplex (actually larger than the Houston metroplex) has some dozen different smaller systems all with various levels of interoperability (either ISSI bridges interfaces, patches, conventional interop systems, etc). Tons of large systems across the country that aren't fully encrypted.

Again, having an interoperability plan negates the need for everyone to be drinking from the same Kool-Aid.

 

[ElroyJetson]

True enough. But I can't help but point out that there are innumerable engineered "interoperabilty solutions" which exist to get around intrinsic non-interoperabilty issues with various types of equipment that COULD have been made to be interoperable quite easily.

I've never been in favor of the simple fact that there ARE vendor specific proprietary features permitted in the P25 standard.

If you can configure a radio from Vendor A in such a manner that an equivalent radio from Vendor B can not be fully interoperable with it without adding additional equipment to the system, then you've actually defeated the concept of interoperability.

Let's say this M system is using CC Shuffle and ADP.....you can't buy an H radio that'll just work with that.

I'm not on the P25 planning committee but if I were I'd be beating the "NO PROPRIETARY FEATURES" drum as hard as I can.

Radios should be as interchangeable as bolts made by different vendors but to the same standard specs.. A 1/4-20 Grade 8 Hex Bolt with 1/2" head, OAL 2.0, thread length 1.0, Class 2 fit, should be fully interchangeable with another maker's bolt having the same specs.

Radios for public safety systems should be no different in concept. Buy a radio from vendor A, B, C, M, H, or T....makes no difference. They'll all work the same on the same system, no questions asked.

Anything less than that is " interoperabilty* " with an asterisk, which means someone is playing games with the intent of the requirement for interoperability with the ultimate goal of locking a customer into using only a specific vendor's subscriber equipment.

I'm sure that when my county implements the P25 switchover, they'll probably do something to make it proprietary to H radios. If they can, they will try.

 

[slicerwizard]

What is CC Shuffle?

 

[ElroyJetson]

It's an option Motorola offers which has the functional result of rendering scanners useless as they can not track the control channel data.

It implements a change to the control channel data format which requires the radio to have the CC Shuffle option in order to correctly interpret the CC data.

GE/Harris does functionally the same thing with ESK.

I do not know if Motorola is currently offering CC Shuffle or if it is active on any systems. It may be an obsolete option.

 

[slicerwizard]

Let's say this M system is using CC Shuffle and ADP.....you can't buy an H radio that'll just work with that.

What Motorola 3600 bps CC systems have ever used ADP and why would a Harris radio ever be expected to work on such a system?

What Motorola P25 systems have ever used the (3600 bps CC system -specific) shuffled bandplan feature?

 

[ElroyJetson]

Those questions are kind of beside the point, don't you think? My point is one I can make with clarity: If two different systems can both be "P25 compliant" without being natively interoperable, then clearly "interoperability" has not been codified into the standard as a high priority. There should be no room in the standard that allows vendors to create non-interoperable solutions. In my opinion.

As long as a vendor can sell a system which, due to its proprietary nature, excludes other vendors from selling into it and giving the taxpayer the best usage of his tax dollars, then I'll continue to take issue with the P25 standards allowing proprietary solutions.

 

[KevinC]

What Motorola 3600 bps CC systems have ever used ADP and why would a Harris radio ever be expected to work on such a system?

What Motorola P25 systems have ever used the (3600 bps CC system -specific) shuffled bandplan feature?

I "believe" two systems used shuffled bandplans after they rebanded. I can probably research that if you really want to know which ones, but I can't guarantee results.

 

[slicerwizard]

You could research that, but it wouldn't answer the question, as they're old Motorola systems. As I understand it, the answer to both questions is "none".

In a discussion of P25 interoperability, bandplan shuffling is a non sequitur.

 

[mmckenna]

In a discussion of P25 interoperability, bandplan shuffling is a non sequitur.

And the P25 committee is working on a standard for link layer encryption, which will be a good thing, and should have been part of the original standard. Encrypt the control channel and a lot of annoying problems go away.

 

[slicerwizard]

I suspect that vendors (whose name start with M...) prefer to drip feed the standards. Makes it easy to sell upgrades for years.