[FedCom] ProVoice on Fed Channels?

Tue Apr 25 10:51:58 EDT 2006

Gentlemen,
I guess I need to clear-up some of the confusion regarding
ProVoice...

ProVoice is simply Ge's (now M/A-Com's) third generation
digital voice format.  PERIOD.

But rather than selling it as a option for conventional and
edacs, similar that what was done with VoiceGuard and
AEGIS, Product Management decided to only offer ProVoice as
an upgrade from EDACS.  IE: It is only offered as a higher
level version of edacs, and not offered in conventional.

Yes, it will work in conventional, but it was never sold as
conventional only.  

99% of ProVoice (edacs) systems are on 800 MHz.  

There is one lone 900 MHz system outside of the USA.  Most
people are not aware of this, but part of ProVoice's DSP
processing algorithm is a superior voice "scrubber" system
does a very good job of cleaning-up TDI noise in simulcast
systems.  This 900 system uses ProVoice not for comsec, but
to tidy up the receive voice quality for the users.

THERE ARE NO VHF-HIGHBAND OR UHF PROVOICE SYSTEMS.

I listened to the audio samples over on Lazygranch's
website.  It is aegis digital format using des encryption.

BTW: Encrypted aegis sounds a wee bit different from
unencrypted aegis.

Below are a list of terms for both Moto and GE equipment
that I used in a technical discussion a few years ago on
crypto systems in land mobile radio (LMR).  I thought I
might be useful in this forum.

Those of you who know me, also know what I do for a living,
and that I am knowledgeable of what am talking about.  I do
not often post, but felt I needed to in this case.

Back to lurk mode....   :o)

Mark C.

-------------------------------------------------------------
Motorola Terms:
-------------------------------------------------------------
VSELP..........Vector Sum Excited Linear Prediction
IMBE...........Improved Multi-Band Excitation

DVP............"Digital Voice Protection", Motorola's 1st
generation in-house encryption algorithm
...............Developed in the mid-1970's.
...............VSELP based, uses a 12,000 baud data stream,
will operate on a 22 kHz wide channel.
...............32-bit key code.
...............Self-synchronizing mode of operation,
coverage range 40% less due to Rayleigh Fading.

DVP-XL.........2nd generation of DVP.
...............32-bit key code.
...............Uses a sync header and periodic sync updates
to overcome Rayleigh Fading. Range closer to analog.

DVI-XL.........Exportable variant of DVP-XL.
...............Uses a sync header and periodic sync updates
to overcome Rayleigh Fading. Range closer to analog.

DES............"Digital Encryption Standard", US Government
encryption algorithm  (FIPS 140-1)
...............Uses a 64-bit code (56-bit key + 8-bits of
parity)
...............VSELP based, uses a 12,000 baud data stream,
will operate on a 22 kHz wide channel.
...............Self-synchronizing mode of operation,
coverage range 40% less due to Rayleigh fading.

DES-XL.........2nd generation of DES.
...............Uses a sync header and periodic sync updates
to overcome Rayleigh Fading. Range closer to analog.

MOTOROLA 2-Way Encryption Primer:
Please see: <http://www.batlabs.com/encrypt.html>

-------------------------------------------------------------
General Electric Terms:
-------------------------------------------------------------
Voice Guard....GE's 1st generation digital voice format.
...............Developed in the 1982, uses a GMSK (Gaussian
Minimum Shift Keying)
...............Uses a 9,600 baud data stream, will operate
on a 15 kHz wide channel.
...............Uses a sync header and periodic sync
updates, range 25% greater than analog due to error
correction.
...............Available in VGE and DES encryption
algorithms.

AEGIS..........GE's 2nd generation digital voice format.
...............Developed in 1992, uses a AME (Adaptive
Multiband Encoding)
...............Uses a 9,600 baud data stream, will operate
on a 15 kHz wide channel.
...............Recovered voice quality 10x better than
Voice Guard.
...............Uses a sync header and periodic sync
updates, range 25% greater than analog due to error
correction.
...............Available in Unencrypted digital, VGE and
DES encryption algorithms.

ProVoice.......GE's 3rd generation digital voice format.
...............Developed in 1995, uses IMBE (Improved
Multi-Band Excitation)
...............Uses a 9,600 baud data stream, will operate
on a 15 kHz wide channel.
...............Recovered voice quality 15x better than
AEGIS.
...............Uses a sync header and periodic sync
updates, range 25% greater than analog due to error
correction.
...............Will function in >10% BER (Bit Error Rate)
conditions due to DSP coding.
...............Available in Unencrypted digital, VGE and
DES encryption algorithms.
...............DSP provides reduced TDI noise in simulcast
systems.

VGE............"Voice Guard Encryption"  GE's in-house
encryption algorithm.
...............64-bit code, with 1.8 x10(19) possible
codes.
...............Can be increased to 128-bit code through the
use of the "CUE" function, with 3.24 x10(38) possible
codes.
...............Can be exported with license from US
Government.

VGS............A generic designation for a customer
specific encryption format.  

DES............"Digital Encryption Standard", US Government
encryption algorithm  (FIPS 140-1)
...............64-bit code, with 7.2 x10(16) possible
codes.

UNENCRYPTED....Digital audio, no encryption.
...............Provides minimal protection from monitoring
(IE: Scanners)
...............DSP provides reduced TDI noise in simulcast
systems.

<end>

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