scanSydney

Mike,

Handout radios & liaison support (in other words a local travelling with them) is the most likely for something of 24-48 hours duration. For something longer (ie. Christchurch earthquake) radios would be programmed up on arrival- that was precisely what NSW Police did in Christchurch. Police had access to the NZ P25 network once radios were reprogrammed by a tech who was flown in (and from what I heard EXCELLENT co-operation between Moto & Tait).

Interoperability does not mean having access to every network, every talkgroup, in every state, 365 days a year on the chance of a once in a few years or a decade event. That is nuts. I write these radio profiles as part of my job- just having NSW talkgroups & liaison channels is a large enough profile. Half the users are hard pressed to know how to change zones regularly used... and you want more? There is also the network security issue- each of these networks have their own network ASKs- so who is going to program them? I can do NSW, and SA by specific consent, but I can't do MMR. No-one (other than certain people in Moto) has the authority to program all 3- and then only with the consent of the network owner/manager.

The biggest problem of interoperability I see is people not knowing which channels/talkgroups to use... and never bothering to practice using them till the big day comes...

The world has moved on since Tracy... technology lets us do things on the fly without the problems faced in 1975.

Cheers,


Richard

are the GL or ESO talkgroups standard across the 3 networks, (ive only ever looked at the NSW GRN), would that be an option having a set of talkgroups standard in all radios on all networks(nsw, sa and victoria)?

They can't be... different network ID's, different talkgroup ID allocations. What is possible in the future is for there to be talkgroups in SA (when it becomes a full P25 network in some years) and the Victorian MMR that look the same- but they will not be the "same" talkgroups. There is no reason why the talkgroups couldn't be linked to the home network... inter-network linking has been tested successfully.

There's no need for ASKs for each system to enable roaming between ISSI linked P25 systems.

As an example, say you've got the GRN, and it's linked to MMR. You get off the plane and fire up your GRN radio. It does a full spectrum scan for control channels, it finds MMR advertising the same WACN ID, grabs the implicit band plan broadcasted on that MMR site's CC, and attempts to affiliate.

MMR's VLR (Visitor Location Register) then contacts the GRN's HLR (Home Location Register), and asks whether your radio is a valid GRN radio, and whether it is permitted to roam to MMR. If yes, your radio get granted access to the system. Voice and packet data between your radio and resources on your home network gets transmitted back and forth over the WAN link between systems using SIP/RTP.

Interop talkgroups get mapped at the system level; there's no requirement for the same talkgroup ID to be used across systems.

Where's the "like" button for the above post

Well after reading all your posts, I think I was ahead of myself with regard to the current inter-state inter-op status. Maybe when the 403 - 430MHz band is cleared for Fed/Govt use only, the situation may change.

Cheers
Mike