Terrasat Tx Redundant System IBUC

Satellite terminal redundancy switching has used the same technology for many years. RF Transceivers and SSPAs provide contact closures in case of failure and a redundancy switch logic controller, mounted in a rack indoors, provides the logic and control to switch from a failed unit to an operational unit. Multi-conductor cables carry the signals from the RF units indoors to the logic controller and back out to the waveguide switch at the antenna feed.

While this type of solution does work, the redundancy switch logic controller is a fairly expensive device, often costing several thousands of dollars. The customer or integrator must also provide multi-conductor cable bundles between the indoor and outdoor units. Then there is the complexity and time required to wire it all together and set up each RF unit.

Terrasat’s integrated approach implements new technology to eliminate most of these elements with their cost and complexity. Instead of routing voltages over multiple cables to and from an external logic device, the switching logic and drivers are incorporated into the IBUC itself. A small junction box, mounted on a plate assembly with the redundant IBUCs, routes information between the IBUCs and provides the customer interface on TCP/IP, RS232, and/or RS485. Local setup and monitoring are as simple as viewing embedded web pages or using an optional handheld controller.

The basic function of the redundancy system is to automate switching to a secondary IBUC in the event of a failure in the primary unit. At the outset of product design, Terrasat determined to take an innovative approach that would: • Strengthen protection for the customer – no single point of failure

• Decrease complexity – simplify the installation

• Reduce cost

• Provide rich, full-featured management, monitoring, and control

Earlier technology RF Transceiver and BUC redundancy systems often relied on an external logic controller. This is typically a device that is mounted in a rack inside the equipment shelter. It accepts major alarm contact closures from the Outdoor Units (ODUs) and makes the switching decision. The drawbacks are:

1. Limited information upon which to base the switching decision – normally selected by the manufacturer - with no ability given to the customer to modify alarms for local conditions

2. The added cost of the logic controller unit

3. High cost and complexity of running cables between the controller, the ODUs, & the waveguide switch

Terrasat took an entirely new approach in developing a complete 1:1 protection system that does not rely upon a third party logic controller unit. Since the IBUC is an intelligent device with sensors, microprocessor and software, it was a matter of incorporating the decision-making function into the Block Upconverter itself. This eliminates the rack-mounted logic controller with its expense & additional cabling. All signal routing is managed through a small interface junction box mounted on a plate along with the two IBUCs. Since the IBUC is an integrated package design (BUC and SSPA in a single enclosure) it is possible to monitor multiple functions in both the BUC & SSPA sections to give true, robust redundancy.