Theory Of Operation - COBHAM M2ECHPT Operation Manual

 Analog and Embedded Audio
 Transport Stream Steaming via LAN or ASI or Serial Interface
 User Data Option
 Control via LAN Web Server or Serial Interface
 +12Vdc or +28Vdc Option
 Companion COFDM Receiver with Post-Detect Diversity Reception

3.4 Theory of Operation

The M2ECHPT Series "Messenger Two Series" product line incorporated AVC/H.264 compression
technology with ultra-low delay that covers all the SD and HD formats up to 1080p. AVC compression
provides dramatically increased compression efficiency over MPEG-2 which allows our link to provide
superior coverage over a wider operating range!
There are two core hardware configurations for M2ECHPT. The SD/HD-SDI configuration accepts up to
two Standard Definition (SD) or High Definition (HD) 4:2:2 Digital Video (SD/HD SDI) or analog
composite Video and Analog Stereo Audio Inputs (Mic or Line Level) and Embedded Audio (up to a
total of two stereo pairs or four mono channels) set or programs. Mic bias is also provided. In the
HDMI configuration
both digital video and audio. Dual SD Composite Video inputs are also provided with the HDMI
configuration
Both Video programs can be compressed according to the Advanced Video Compression (AVC)/H.264
(HD/SD) specification with the same or different frame resolutions, rates and formats. The low-latency
AVC Encoder supports the Baseline Profile with extensions with resolutions from 480 to 1080 with
support for either interlaced or progressive formats. The Audio is compressed using MPEG-1 Layer 2
compression. Low rate user data up to 115KBaud can be optionally supported. Both programs, Audio,
Video and User Data Packets PES Streams are multiplexed with Basic Service Data to indicate their
respective Service Names. If two programs are active, the two transport steams are multiplexed into a
single multi-program stream. The stream can be optionally scrambled with AES scrambling system to
provide protection in sensitive applications. User selections for all transport stream ID numbers and
service names are provided.
The M2EPHT is a complete system with Audio/Video encoders/compressors and all the required
processing to transmit the modulated signal with up to 15W (band dependent). CS' COFDM wireless
equipment provides a standard robust digital modulation system known as Coded Orthogonal
Frequency Division Multiplexed (COFDM) that provides frequency diversity and powerful Forward Error
Correction (FEC) algorithms. This modulation is ideal for transmitting over water or into urban
environments which typically have high multi-path interference.
Our Messenger Receivers include an option for Spatial Maximal Ratio Pre-Detect Diversity to combat
multipath reflections found in indoor/urban environments. Cobham's Messenger six or eight channel
receivers with associated Messenger Antenna Arrays (MAAs) provide wide reception range without the
hassle and cost of an auto tracking antenna system. The Messenger series Tx/Rx products provide a
robust wireless link that is effective against the multipath interference experienced by analog systems
and provides reliable data transmission in the most difficult of terrains.
100-M0177X1
GMS Inc. doing business as Cobham Tactical Communications and Surveillance
*P4
, the SDI/HD-SDI interfaces are replaced with two HDMI interfaces that accept
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www.cobham.com/tcs