[Namaste-dev] Re: Interoperability through APCO-25

Eric Blossom eb at comsec.com
Thu May 22 11:44:07 PDT 2008


On Thu, May 22, 2008 at 10:02:31AM -0700, Michelle wrote:
> Emergency communications interoperability through an APCO-25 terrestrial interface has been proposed.
> This would increase emergency communications usability and increase opportunities for funding.
> Here is a short introductory article on APCO-25. 
> http://en.wikipedia.org/wiki/Project_25
> Here is an industry article about APCO-25.
> http://www.info4u.us/APCO25/
> Here is the project home page.
> http://www.apco911.org/frequency/project25/index.html

> There is an information page of interest at the same site as the home page.

> http://www.apco911.org/frequency/project25/information.html

> People "in the know" refer to the standard as P25.1, meaning APCO
> project 25 phase 1, which is the current phase. Phase 2 and up
> are in development.  What I'd like to do is explore the idea of
> using a cognitive radio module to handle the interoperability. This
> would rely upon Tom Rondeau's work, as explained in his
> dissertation. What I need are people that are interested in
> taking on the responsibility of supporting this terrestrial module
> for Namaste. This means learning the standards well enough to assist
> in writing and reviewing requirements, establishing the feasibility
> of using cognitive radio technology to bridge between our IP layer
> and external APCO-25 waveforms, and then supporting the design
> effort.

I understand the desire for funding, however...

After talking with Vanu Bose (www.vanu.com) about various public safety
interoperability offers they had made, he indicated that the issue is
not technical, but is one of policy and politics.  It's about
maintaining a chain of command.  The fire chief doesn't want other
people talking to her crew, and doesn't want them listening to anybody
else either.

Is being "open" and "free" a design objective / requirement?

Last time I checked, the P25 specs weren't open and cost about
$2.5k unless you were law enforcement or government.

How would you handle the proprietary vocoder?
How about any patents relating to P25?

Of the public safety systems installed, what percentage of them are
using P25.* vs EDACS vs anything else?  Of the current P25
installations, how many of those are running Motorola proprietary
extensions?


Summary: if you're willing to sacrifice open and free as a
requirement, then yes, it's possible to create a gateway to/from P25.
I'm not sure how much cognition is involved in any of this.  Other
issues include mapping to/from talk groups, authentication,
encryption, and arbitration of big pipe into little pipe.

Eric K7GNU


More information about the Namaste-dev mailing list