Media Access Control (Mac); Operating Modes; Management Tools; Security - Javad UHFSSRx User Manual

MEDIA ACCESS CONTROL (MAC)

The following Media Access protocols are available for AW400Rx modem:
Simplex protocols (Simplex Base, Simplex Remote, and Repeater) are developed primarily for GNSS applica-
tions.
Sleep mode is an investment provided by MAC sub-layer that provides additional power saving. The wakeup
from Sleep mode is user selectable either by an internal real-time clock, or by an external controller through
the data interface control lines (RTS or DTR), or by SLEEP input line (CMOS/TTL compatible input lines).

OPERATING MODES

The operating modes for UHFSSRx can be set through the CLI, and/or through AWLaunch. The following oper-
ating mode are available for UHFSSRx :
The sleep mode has automatic transmitter activation by an internal real-time clock, or by an external control-
ler through the data interface control lines (RTS and DTR), or by the triggering of the external Sense Inputs.

MANAGEMENT TOOLS

The built-in management tools along with AWLaunch (configuration and monitoring software application)
will provide the following benefits:
1. Easy user's interface for system configuration and monitoring using well developed CLI or intuitive GUI.
2. An ability to monitor status, alarms and radio performance through the intuitive GUI.
3. Software upgrades and improvements can be downloaded from AWLaunch to the units connected with
PC/PDA.

SECURITY

The system provides wireless media access protection as well as data encryption. The following are its key
features and benefits:
1. The Key Sequence generated by Pseudo-random generator scrambles the fully formatted frame (including
Frame's CRC). This provides the wireless media access protection.
2. User selectable Frequency Hopping Pattern provides another level of the wireless media access protec-
tion.
3. At the same time it allows operators to increase the number of links deployed in the same location.

Operating at Spread Spectrum Band

The Spread Spectrum (SSR) technique in which a signal is transmitted on a bandwidth considerably larger
than the frequency content of the original information.
Spread-spectrum telecommunications is a signal structuring technique that employs direct sequence, fre-
quency hopping or a hybrid of these, which can be used for multiple access and/or multiple functions.
This technique decreases the potential interference to other receivers while achieving privacy. Spread spec-
trum generally makes use of a sequential noise-like signal structure to spread the normally narrowband in-
formation signal over a relatively wideband (radio) band of frequencies. The receiver correlates the received
signals to retrieve the original information signal.
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