Cisco 12 dB FST Inverse EQ

The Cisco® 1.25 GHz Surge-Gap Flexible Solutions Taps (FST) are the latest products designed for the DOCSIS® 3.1 evolution of hybrid fiber-coaxial (HFC) networks. DOCSIS 3.1 technology allows cable operators to fully and efficiently use their broadband networks to provide the services that subscribers demand. As part of DOCSIS 3.1 support, the broadband operating frequency range has been increased to cover the entire 5 MHz to 1.218 GHz spectrum.

These products are also fully compatible with orthogonal frequency-division multiplexing (OFDM) signaling requirements. These new capabilities can contribute to higher customer revenue by allowing increased bandwidth across a network, so new and improved services can be provided. The taps offer best-in-class performance along with added flexibility in system design. This flexibility is achieved using three types of optional plug-ins that are ideal for higher output, deep-fiber architectures.

Optional Plug-Ins

? Reverse attenuators are available in 0, 3, 6, 9, and 12dB values. The attenuators increase the reverse path tap loss with only a minimal effect on forward tap loss. By selectively adding reverse attenuation to reduce reverse tap values, reverse path tap losses can be more similar across the various values of taps used in an HFC network. This approach allows the range of RF levels transmitted from closed-loop customer premises equipment (CPE) to be narrowed, which helps improve the reliability of upstream transmissions.

? Forward equalizers used in Cisco 1.25 GHz Surge-Gap FST products are available in 2, 3, 4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20 and 22dB values. The forward EQs increase the forward path tap loss in a standard cable-tilted fashion, with greater loss at lower frequencies than higher frequencies. The plug-in forward EQ allows optimization of tap output levels at tap locations near the end of the feeder line.

? Forward inverse equalizers used in Cisco 1.25 GHz Surge-Gap FST products are available in 2, 3, 4, 6, 8, 9, 10, 12, 15, 18, and 21dB values. The inverse equalizers increase the forward path tap loss in a down-tilted fashion, with greater loss at higher frequencies than lower frequencies, and they have only a minimal effect on reverse tap loss. The plug-in forward inverse equalizer allows tap output levels to be optimized at tap locations with high-level forward RF signals and significant up-tilt (typically, they are tap locations closest to nodes and amplifiers).

Cisco 1.25 GHz Surge-Gap FST products all have IEEE-compliant 6-kV surge protection, providing significantly improved protection against voltage transients in lightning strike areas and locations with unreliable power networks. In addition, the new tap products offer the same AC/RF Bypass Switch capabilities of previous Cisco tap products, allowing the tap faceplate to be removed without interrupting service to downstream customers. The taps pass up to 12 amps of current, so operators can access power at locations within the HFC plant where additional power is needed.