User Manual

SECTION 1: THEORY OF OEPRATION
IP4HPVGPS-MRFCCRpt.doc Page 3

General Block Diagram
General Block Diagram Definitions
For increased data security, the modem supports the Federal Government developed Digital
Encryption Standard (DES) data encryption and decryption protocols. This capability requires
installation of third party, Internet Protocol (IP) compliant DES encryption and decryption
software on the system.
The IP4HPV mobile radio is comprised of two (2) circuit boards, the digital board and the RF board. The
digital circuit board contains the following sections:
Input/Output Circuitry associated with the radio’s DB9 data connector providing all the
RS232 data and handshake functions, including the necessary level
changes.
Microcontroller Manages the operation of the radio, the modem, and determines which
receiver provides a better signal from a given transmission. Also provides
transmit time-out protection in the event a fault causes the radio to halt in
the transmit mode.
Modem Converts serial data into an analog audio waveform for transmission and
analog audio from the receiver to serial data. Within a single chip it
provides forward error detection and correction, bit interleaving for more
robust data communications, and third generation collision detection and
correction capabilities.
Power Supply The power supply creates the various voltages required by the digital
portion of the mobile radio.