General Description
The Network Voting System incorporates a set of ground receiv¬er sites to provide downlink reception beyond the capabilities of a single, fixed site where appropriate network infrastructure ex¬ists. The exact placement of the receiver sites and the antenna configuration at each site is designed by ECS to provide optimal coverage according to the Customer’s bespoke operational requirements, siting arrangements and terrain. Simultaneous downlinks from multiple platforms may be distributed to moni¬toring sites across the network.
The downlink signal is converted to Internet Protocol (IP) data before being delivered securely and bandwidth efficiently across the Customer’s own network to a monitoring point or multiple points of the Customer’s choosing.
A voting technique is used to select the best real time downlink signal available from multiple receiving sites. The system uses smoothed signal quality and packet error data to select the most consistently reliable downlink feed for each channel, incorporat¬ing a hysteresis effect to minimise unnecessary switching while remaining responsive to sudden data losses.
Control of the system is via a Voting System GUI which may be located anywhere on the network. The GUI includes selection of the receiver channel, video encoder mode and encryption keys. The GUI can also provide manual control of tracking or switched antenna systems at the receiver sites and, manual over-ride of the receiver site for each downlink channel. The GUI includes a Built in Test (BIT) function and allows system monitoring.
Technical Data
Components: -Ground Receiver Site/s
-Ethernet (IEEE 802.3) Network.
Quality of Service (QoS) must be guarenteed at the band-
width required to egress downlink data on each net
work segment.
-Operations Monitor Centre/s (video displays)
-Network Voting System GUI
GUI Control: -Encryption Key for each receiver
-Receive Channel for each receiver (Frequency)
-Downlink Parameters (Forward Error Correction, Modulation and Guard Interval)
-Video Standards (PAL / NTSC)
-Manual selection of Multi Sector Antenna sectors
-Manual selection of receiver for each downlink channel.
GUI Monitoring: For each receiver: packet error, alarm, signal quality, ranking and feed status.
GUI Software Requirements: a PC running Microsoft Windows® 2000, XP or Vista
operating systems. The GUI software utilises hardware
key protection and is implemented using the Microsoft .NET framework.
