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Applications:
- High-Security Surveillance Applications
- Helicopter links
- UAV/UGV Applications
- Mobile and Portable AV Applications
Key System Features:
- Secure – Optional Fixed Key Scrambling System or AES
- COFDM Modulation
- Output Frequency: 1 to 6 GHz (In-Bands)
- Low System Latency (~40 mS)
- Built-in MPEG-2 Encoder
- Up to 30 Mbps data rates
- Rugged and compact portable design
- Companion COFDM Receiver (MDR) with Diversity Reception
The Messenger Digital Link (MDL) includes the Messenger Digital Transmitter (MDT) and the Messenger Digital Receiver (MDR). The MDL provides a unique combination of security and link reliability for the most demanding short or long distance Audio/Video (A/V) point to point transmission applications. MDL uses a robust digital modulation system known as Coded Orthogonal Frequency Division Multiplexed (COFDM) that provides frequency diversity and powerful Forward Error Correction (FEC) algorithms.
The Messenger Digital Receiver (MDR) includes an option for Spatial Diversity Combining to combat short delay spread multipath reflections found in indoor environments. The MDL provides a robust wireless link that is effective against the multipath interference experienced by analog systems, and provides crisp, clear pictures in the most difficult of terrains.
The MDT accepts a composite video input, analog stereo audio inputs and a RS232 data input. The video is compressed according to MPEG 2 specifications. The audio is converted to a 728kb/s stream. The audio, video and data packet streams are multiplexed with basic service data to indicate the service name. The stream can be scrambled with a simple fixed key scrambling system to give basic protection in sensitive applications.
One of the biggest problems encountered in the transition from an analog to a digital A/V platform has been the inherent digital coding delays that in some digital systems are 400ms or more. The MDT/MDR combination employs a specially designed ‘low delay’ coding technology, which provides an end to end latency of approximately 40ms without the introduction of any further MPEG encoding artifacts. This ensures that the picture you see is what is happening now - crucial for applications such as sports coverage, surveillance, and law enforcement, where personnel are reacting to real-time events.