PG's new system

[gr8tff]

Is there any word on PG's new system? Timeframe and system type?

 

[WA3CSX]

pg's radio system

august of 2009,they are only two years behind

 

[ScanManQSL]

Can someone correct me if i am wrong. If i can remember correctly Prince Georges county is going to be a 700 MHz /\/\otorola APCO Phase II, TDMA trunked radio system. They should be testing the trunking system some time in mid 2009.

 

[WA3CSX]

Pg Radio System

You Are Correct!!!

 

[TommyP]

august of 2009,they are only two years behind

Two years behind what?

 

[baybum]

I understand this new system cannot be monitored.
Can someone who works with this type of system explain, briefly and in laymans terms, why?

 

[ka3jjz]

As far as I understand it, because it's TDMA.....I'm not sure what 'phase II' refers to, though.

Yes, for now at least, it won't be monitorable....73 Mike

 

[baybum]

Yes, I see where it says TDMA, I'm looking for a basic explanation of why it's not monitorable.

Thanks.

 

[ajpritch]

The reason it can't be monitored is that it is P25 Phase 2 which is TDMA. Currently there is not a scanner that can decode phase 2 but hopefully there will be one soon

 

[baybum]

Again, I see where it's TDMA...but I don't know what that is and how it is related to radio and why it is unmonitorable.
Judging by the Google searches that I've done...maybe it's too difficult to put into laymans terms.

 

[AlexC]

The reason it can't be monitored is that it is P25 Phase 2 which is TDMA. Currently there is not a scanner that can decode phase 2 but hopefully there will be one soon

I wouldn't expect one soon. There currently is no established P25 Phase 2 protocol that is "open." Most vendors who are looking at or are rolling out Phase 2 equipment are using their own protocol, hoping that it will be adopted as the standard. Because of this you won't find anyone licensing the protocol to build a scanner.

What's one of the greatest selling points of a phase two system right now? No one can monitor it without a subscriber radio.

The reason why you saw P25 scanners was that it was a protocol anyone could adopt and build into their equipment.

-Alex

 

[ajpritch]

Here is a link to the WIKI to explain it. http://wiki.radioreference.com/index.php/Project_25 Scroll down and look for Project 25 Future Developments. It will basically allow twice the capaciaty by allowing two users on a single channel.

Does that help explaing it? It basically the same idea of why a Tmobile or ATT phone wont work on a Verizon or Sprint network just different technologies.

 

[baybum]

Yes, that helps.

Thanks.

 

[ResQguy]

For what its worth, the system will only be "partially unmonitorable". Expect there to be enough FDMA talkgroups to keep you in the know.

 

[baybum]

ResQ, what is your source for that info? Or is that a suspicion?

 

[ajpritch]

I am not aware of a Project 25 system that can do both FDMA and TDMA at the same time unless they are two systems that let users roam as its two different technolgies. They might however choose to encrypt just certain talkgroups like VICE and Tactical talkgroups.

 

[fd2119]

ResQ, what is your source for that info? Or is that a suspicion?

I would feel very safe in saying that ResQguy is very much in the know.

 

[baybum]

Not questioning his knowledge...just asking for clarification.

 

[ocguard]

I am not aware of a Project 25 system that can do both FDMA and TDMA at the same time unless they are two systems that let users roam as its two different technolgies. They might however choose to encrypt just certain talkgroups like VICE and Tactical talkgroups.

I am not aware of any other P25 systems that have been implemented for Phase II (TDMA operation) other than Morotola's. And the very premise of Project 25 (common air interface, non-proprietary compatibility, reverse-compatibility) would make me think that Phase II systems should be configurable for Phase I operations as well. Reading up on this confirms that Motorola Phase II systems are capable of dual-mode (FDMA and TDMA).

 

[ResQguy]

ajpritch is close with his "roaming" suggestion. That is about as descriptive as I think I can say. Rest assured that most FDMA radios in the region will be interoperable with this system.