Axnes AS
Document number
Revision
Date
AX-PNG-UMAN-1220
Issue C
2018-Jun-05
Page 2-2
Confidential document and information
Configurations
Both the MP50 and the PNG Base Station use configurations to control the behaviour of the
devices. They can hold a number of configurations, with different operation parameters. A
configuration contains a minimum of the following parameters:
•
Logical name of the configuration
•
Radio parameters (frequency, modulation, and channel bandwidth)
•
Group subscriptions for receive
•
Group subscriptions for transmit
•
Configuration of remote PTT control (handheld activation of PTT from the base
station to the intercom)
The different pre-programmed configurations can be selected at start or during mission from
the PNG Control Panel. Typically, there will be several configurations when different radio
channels shall be made available. There can also be different configurations for different
mission types as e.g. SAR, EMS and MEDIVAC missions.
On the MP50, the configuration is selected with the up/down arrows, and identified with a
short two letter name and a long logical name (scrolling display).
Pre-programmed configurations can either be pre-ordered from the equipment vendor, or
changed by a qualified equipment operator with a PC based programming tool.
2.2.1 Encryption
With the PNG system all intercom user data are encrypted according to the AES-256
encryption standard before they are transmitted over the air. When delivered from factory,
the PNG handheld uses a default encryption key called “AXNES DEFAULT”. Changing this
encryption key requires the user to acquire an encryption key programming kit. Note that the
PNG Base Station and all handhelds in a system must use the same encryption key in order
to connect and communicate with each other.
Note: Direct mode communication (Maritime VHF, and other FM modulated configurations) is
open unencrypted communication. Only communication through BST50 is encrypted.
Noise cancelling
The MP50 implements active noise cancelling of the microphone signal. Noise cancelling
ensures very high performance of the VOX operation, and speech intelligibility, even in
extremely noisy environments such as directly in front of a landing helicopter or similar. The
noise cancelled signal is transmitted on the radio, and used in the side tone. When using the
MP50 in windy environments, the microphone should always have a windsock mounted. It
should be noted that in quiet environments the noise cancelling can be noticed as a light
noise in the side tone during the quiet periods, and should be expected.
