Pearl Harbor Naval Station - 6 channel Smartnet system

[911_Radioman]

Trying to figure out if this system is still analog, or is, indeed digital.

Online info says it's Smartnet II (3600 baud Control Channel signalling).

They're using XTS-3000s as subscriber units...these are capable of analog or digital operation (with the right firmware in the backend).

Can anyone tell me if it's 3600 baud and analog or (VSELP) digital? Could it be an early IMBE (digital) vocoder (5.0?)

Many thanks

 

[INDY72]

Its most likely a ASTRO (non VSELP) Mixed mode, with most talkgroups probably in ASTRO Digital Mode. There are - as far as I know - NO VSELP systems in use at military installations.

 

[911_Radioman]

They've used the term 'ASTRO' to describe both VSELP or IMBE digital.

When you say 'mixed mode', do you mean multiple personalities in the radio (some analog talk-groups, some digital).

Anyway of telling what vocoder (e.g. which IMBE version they're up to)?

Thanks for the answers.

 

[dlmphotog]

Motorola Type II TRS in digital mode

Check out David Cabatu's web site... a great source for scanning in Hawaii

http://www.qsl.net/ah7e/pharbor.html

Aloha,

 

[911_Radioman]

Naval Station Pearl Harbor - thanks to all

Ahuwale ka po' okela i kau hana ia ha'i

(It is through the way you serve others...)

 

[INDY72]

Mixed mode refers to both analog and digital in usage on a system.

Most ASTRO systems use IMBE CAI. A few of the older ones are VSELP, but its being phased out.


There is no way to know what version IMBE is in use unless you can get the info directly from the system admins/techs, or you work for Motorola and are involved in maintaining the system.

If digital is in use, and a digital scanner can hear it... its iether ASTRO using CAI, or ASTRO-25

 

[911_Radioman]

Definitions, please

ASTRO 25?

IMBE CAI (Common Air Interface)?

The first digital 'vocoder' used was a VSELP vocoder - proprietary Motorola.

The P25 standard calls for a 'common air interface'. But the first one Motorola deployed was IMBE (Improved, Multi-Band Excitation) version 5.0.

This worked on a 3600 baud Control Channel signalling scheme. This intermediate step was put in place so that the subscriber unit hardware would have 'time' to catch up. (It also made Motorola a lot of money selling 'new' P25 compliant subscriber units this year and last, that would work at the 'next level'.)

That 'next level' is version 6.0, which is truly P25 compliant. IMBE 6.0 works on a 9600 baud Control Channel signalling scheme. Apparently, they've 'stretched it out' more, and they're up to version 6.3 or 6.4.

'ASTRO 25' means nothing to me. What does it mean to you?

 

[INDY72]

ASTRO-25 is Motorola's name for thier "true" APCO P-25 systems, both conventional, and trunked. The first ASTRO was VSELP, but is now no longer supported and is being phased out. The current ASTRO format is using IMBE Common Air Interface. To be P-25 compliant a system must use CAI in one of the forms of C4FM, or CQPSK. On trunking to be a "true" P-25 system, you must use this with an 9600 kbps CC. ASTRO-25 TRS's are the ONLY "true" APCO P-25 trunked systems in existance currently. The older 3600 kbps ASTRO formats using IMBE CAI are "compliant" to an point. VSELP formats are not. And EDACS Provoice is not, but thats a whole other ballgame.

Another great feature of the ASTRO-25 format is that no matter if you use a single conventional freq, a multiple bandwidth system, simulcast multi-site conventional, a single site TRS (No matter what bandwidth), a Smartzone multi-site TRS, a Omnilinked Smartzone set up, or even a combination of all of the above... they all seamlessly intergrate on the ASTRO-25 platform. Thats what ASTRO-25 means to me.

(Not to mention where I work, we are going to be slowly phasing in a system wide conventional ASTRO-25 net over the next few years.