OVERVIEW

Recently, new developments in compressions schemes provide for significant numbers of programming channels on just one satellite and associated transponders. It is not unusual to see up to 200 channels of programming on just 5 or 6 transponders associated with that one satellite.

In addition, because the higher-powered modern satellites now allow use of smaller antenna systems, prime-focus antennas are becoming the norm for receiving these high-programming-density transmissions.

Because the failure of a single LNB in a prime-focus system can now mean the loss of 100 or more channels, programming providers are insisting on a much higher level of reliability with reference to LNBs than has been previously required for commercial satellite programming delivery to date.

Traditionally, backup capabilities for failed LNBs have been available only for large-aperture satellite antennas with feed systems that provide for LNB mounting on the back of the antenna hub assembly, and associated waveguide switches. These backup systems have not been applicable to antennas with Prime Focus Feed Systems because of the significant weight and bulk associated with them.

In response to the requirements for 99.999% reliability factors associated with satellite programming delivery schemes, SSE is please to offer two "fail-safe" backup systems for their prime-focus antennas. Both redundancy systems use our new SSE RSP 2150 REDUNDANCY SWITCH.

The SSE RSP 2150 REDUNDANCY SWITCH

The new 2150 Redundancy switch is designed to automate the switchover for signal paths in the event of a failed LNB. It also incorporates connectivity for communications with the facility M&C system, providing remote control and monitoring functionality.

LNB power is provided by internal dual power supplies, each with its own separate AC power cord. This ensures that power supply failure will not cause signal loss. In addition, the new Switch has a "hot-swap" feature for Power Module replacement, thus ensuring the overall system is never taken off-line, even for power supply repairs.

The 2150 RF Sensing System monitors an (user preset) input RF level and commands an internal switch to the backup LNB when the primary input RF level falls below the preset Level. At the same time, an alarm is generated to the facility M&C system, and indicated on the front panel.

The internal switching delay of the 2150 is on the order of just milliseconds (from the time of signal loss to the time of signal restoration from the backup LNB). This is short enough to prevent de-authorization of most modern receivers.

It is important to note, however, that most of the delay factors during switchover - for both Redundancy Systems described here - are associated with the Satellite Receiver and depend on where the Receiver may be in its authorization process. This is, of course, a function of the specific authorization scheme and not a factor that we can address in the redundancy switching process. Sometimes then, there may be a delay of a few seconds if it is necessary for the Receiver to re-authorize.

REDUNDANCY SYSTEM 1 - BACKUP ANTENNA

In conjunction with the 2150 Redundancy Switch, a client may elect to simply install a Backup Antenna, complete with LNBs and separate cabling to the equipment shelter.

The 2150 Redundancy Switch monitors the signals from the primary antenna, and switches to the backup antenna in the event of a signal failure, generating an alarm to the M&C system at the same time.

An advantage associated with a backup antenna is that all the switching tasks are measured in milliseconds because there is are no mechanical adjustments associated with a backup antenna.

Prospective users of this type of backup system should also consider the ancillary costs associated with an additional complete antenna system. These extra costs may include civil works (site prep, foundation and cabling requirements), shipping and installation costs and of course the price of the antenna itself.

REDUNDANCY SYSTEM 2 - SSE PARALLEL FEED SYSTEM

The SSE PARALLEL FEED SYSTEM is unique in that it provides for installation of two (2) identical feedhorns on the antenna focal point feed support. For those familiar with our Multi-Beam Satellite Feed Systems (MBF), the PFS looks almost identical to the MBFs, except that the feedhorns are mounted on a mechanical, motorized platform that allows them to be moved laterally. In this system, a failed primary feedhorn/LNB is moved aside and the backup feedhorn/LNB assumes the primary position.

The 2150 Redundancy Switch monitors the primary LNB for a loss of RF Input Level just as with the Backup Antenna System. But, in this system, concurrent with the command to switch RF Inputs, the 2150 Switch also outputs a command to an associated Feedhorn Control Unit for the feedhorns to effect the lateral - "parallel" - movement. The feedhorn shift takes just seconds to complete. This short delay may sometimes cause the Receiver to drop out of authorization and therefore full recovery time is dependant on the specific Receiver authorization scheme.

A manual toggle switch on the Feedhorn Control Unit provides an override function for testing and also is used to drive the feedhorns back to primary/backup positions after the faulty LNB is replaced. The Feedhorn Control Unit also provides alarm functions to allow the M&C system to verify its status and operation.

NAVIGATOR STEERABLE ANTENNAS with Feed Redundancy Option

SSE is pleased to offer our NAVIGATOR 45-III AND NAVIGATOR 38-III Steerable Antenna Systems with the SSE PARALLEL FEED SYSTEM option.

Our NAVIGATOR Steerable Antennas can be positioned to any satellite in the US Geostationary Arc and can access any format or frequency (C and Ku-Band). This has always provided the availability of space-segment backup, allowing the antenna to be easily positioned to a new satellite in the event of primary satellite failure.

And now, the NAVIGATOR Antennas can be configured with the SSE PARALLEL FEED SYSTEM so that ground-segment backup capability is included as well.

Contact SSE at 406-257-9590 (Mountain Time) for more information, or e-mail us at: superior@superiorsatelliteusa.com.