OTAR Control System for Digital Encryption Modules

OTAR - Over-The-Air-Rekeying and radio management – is the common name for the method of changing the encryption keys over a radio channel or “over the air” as well as controlling certain important functions of a radio, REMOTELY.

With OTAR control software system managers can easily log, monitor and manage the radio system using a  personal computer, enabling them easily protect the integrity of their radio system for example, if a radio is lost or stolen it is quickly disabled remotely using the kill/stun feature, which prevents the radio from transmitting or receiving any messages and therefore ensuring that vital messages do not get into the wrong hands.

 Functions and Features

• Over the air re-keying (or re-programming)
  Automatic or manual re-keying of the encryption keys

• Radio Verification
  Discretely checks and verifies that the radio is switched on and is within the coverage
  area (in secret mode).

• Kill Function
  Disable the module if the radio is lost or stolen.

• Stealth or Secret Mode
  Discrete Monitoring / Listening In (secret mode of radio’s transmit)

• Restrict Function
  Temporary restriction of receive and/or transmit of the subscriber.

• SMS Messaging
  Sending of short alphanumeric messages to the radio – secret command
  from other subscribers – only for Motorola radios with LCD display

• Secure Operation
  The OTAR commands are encrypted with 32-bit Master Key (constant within a system)

• Secure Access to Modules
  A password for the module to be re-keyed HAS to be known in order to Re-key it.

Main components of an OTAR system:

• 1. A personal computer PC with special software OBS sends a secure input to:

• 2. A controller, NDM-750m which interfaces between the PC and the transmitter.

• 3. a radio to transmit the secure signal

• 4. Over the air to a subscriber radio

• 5. To radios fitted with Digital encryption modules (NDB-750)