Browse Prior Art Database

CRITICAL MODE OPCODE

IP.com Disclosure Number: IPCOM000006363D
Original Publication Date: 1992-May-01
Included in the Prior Art Database: 2001-Dec-28
Document File: 3 page(s) / 123K

Publishing Venue

Motorola

Related People

Jim Van Bosch: AUTHOR

Abstract

The requirements and flexibiity of enclypted radios continue to grow in the industry. There exists a need for high communications security while still providing flexible features. The application of a critical mode opcode has been applied to the clear/coded modes of operation in a secure radio. This critical mode opcode can allow for two diametrically opposed features, mode slaving and a specific ergonomics switch, to be incor- porated into the radio. Mode slaving allows the user to pre-assign a condition (clear/coded) to a specific channel/mode. When the user changes the channel/ mode, the radio automatically updates the clear/coded status for that channel/mode. In commercial markets, the customers require the ability to change channels and have the clear/coded function mode slaved to a channel. Thus, clear/coded mode slaving is done via a critical mode opcode in commercial markets. In higher security radios, clear/coded mode selection is done via a hardware switch. The benefits of such a design are maximum flexibility between diverse markets, ease of operation for the user, and increased reliability and security ofthe system.

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MOTOROLA INC. Technical Developments Volume 15 May 1992

CRITICAL MODE OPCODE

by Jim Van Bosch

ABSTRACT

  The requirements and flexibiity of enclypted radios continue to grow in the industry. There exists a need for high communications security while still providing flexible features. The application of a critical mode opcode has been applied to the clear/coded modes of operation in a secure radio. This critical mode opcode can allow for two diametrically opposed features, mode slaving and a specific ergonomics switch, to be incor- porated into the radio. Mode slaving allows the user to pre-assign a condition (clear/coded) to a specific channel/mode. When the user changes the channel/ mode, the radio automatically updates the clear/coded status for that channel/mode. In commercial markets, the customers require the ability to change channels and have the clear/coded function mode slaved to a channel. Thus, clear/coded mode slaving is done via a critical mode opcode in commercial markets. In higher

security radios, clear/coded mode selection is done via a hardware switch. The benefits of such a design are maximum flexibility between diverse markets, ease of operation for the user, and increased reliability and security ofthe system.

BACKGROUND

  Common applications for the clear/coded mode change can be seen in Fire 1. In these radios the clear/ coded modes of operation have been controlled by a switch or by a bit in a register. These implementations of the clear/coded mode change do not allow the flexi- bility required in todays diverse markets. The hardware switch is used in high security environments. the soft- ware register is used in lower security radios that require clear/coded mode to be slaved to a channel. In today's demanding environment a design is needed that will sat- isfy both high security and mode slaving features.

vcc

T

Method B

SoftwareRegister

Method A

dw& ClearMode Enable

= CleerfCoded Stitch

Figure 1. Typical clear/coded mode change implementations

0 Motorola. 1°C. 1992 11

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MOTOROLA INC. Technical Developments volume 15 May 1992

CRITICAL MODE OPCODE ure 2). This allows critical functions of a radio to be defined via an opcode s&h that if the operation is

A solution to this problem is obta...