Method and apparatus for N+1 RF switch with passive working path and active protection path

• US 7,817,540 B1
• Filed: 05/08/2002
• Issued: 10/19/2010
• Est. Priority Date: 05/08/2002
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Daruwalla, Feisal, Chan, Roland, Meller, Richard, Chapman, John T., Achilleoudis, Nicos
• Primary Examiner(s): Pham; Chi H
• Assistant Examiner(s): ADHAMI, MOHAMMAD SAJID
• Application Number:
  US10/141,893
• Time in Patent Office: 3,086 Days
• Field of Search: None
• US Class Current: 370/220
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04N 21/239 Interfacing the upstream path of the transmission network, e.g. prioritizing client content requests hybrid fiber coaxial [HFC] networks for upstream channel allocation for video distribution H04L12/2801; flow control in data networks H04L47/10; real-time communication protocols in data switching networks H04L65/00; scheduling or organising the servicing of application requests H04L67/60

Abstract

The present disclosure relates an improved cable data switching unit that provides a fail-over system whereby one line card can protect a plurality of US (upstream) or DS (downstream) channel line cards, providing N+1 protection, with one linecard being able to protect N number of working linecards. When a failure is detected in a working linecard, the signals being routed by the failing linecards are re-routed seamlessly to a protect linecard. This disclosure provides for data to be passively routed, providing for data flow even if power is lost.

Claims

1. A cable data switch, comprising:

a switching module comprising a passive splitter/combiner and a protect switch,

where the passive splitter/combiner passively splits a plurality of customer signals received on an upstream channel into a plurality of working signals and a plurality of protected signals and provides the plurality of working signals to a plurality of working head end units and the plurality of protected signals on a protect output, the protect output being provided to the protect switch, where the protect switch provides one of the plurality of protected signals to a protect head end unit,

where the passive splitter/combiner passively combines a plurality of working signals received from the plurality of working head end units with a downstream protected signal received from the protect switch into a plurality of customer signals, and provides the plurality of customer signals on the upstream channel, where the protect switch receives the downstream protected signal from the protect head end unit; and

a control module coupled to the switching module, the control module being configured to receive a plurality of control signals from the plurality of working head end units and to selectively control the protect switch to provide the downstream protected signal to the passive splitter/combiner or to provide one of the plurality of protected signals to the protect head end unit in response to a control signal from a member of the plurality of working head end units.

2. The cable data switch of claim 1, where the switching module combines and splits signals independent of a supply of power.

3. The cable data switch of claim 1, where the plurality of working head end units are configured to communicate with the control module using Simple Network Management Protocol (SNMP).

4. The cable data switch of claim 3, where the plurality of working head end units communicate with the control module over an Ethernet-compliant link.

5. The cable data switch of claim 1, where the member of the plurality of working head end units provides the control signal in response to a failure of a line card in the member working head end unit, where the failure of the line card results in a loss of a working signal from the member working head end unit or the member working head end unit failing to route the working signal received from the passive splitter/combiner.