M-CMTS Resource Reservation Over DEPI Interface

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Solution Overview

Problem

Cable operators face challenges in providing Modular Cable Modem Termination Systems (M-CMTS) with control over network resources and reserving Downstream External Physical Interface (DEPI) resources efficiently, while also managing Radio Frequency (RF) channels without modifying existing intermediary devices.

Innovation Solution

A modified resource reservation protocol allows the M-CMTS core to reserve network and RF channel resources by generating a reservation request with specific parameters, enabling intermediary devices to transparently forward the request and reserve eligible RF channels without reconfiguration, leveraging existing protocols like RSVP for backwards compatibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the M-CMTS core uses standard RSVP protocol to reserve network resources, then network resource reservation is achieved, but RF channel reservation capability is lost

Engineering Contradiction:

Improvenetwork resource reservationVSAvoidRF channel reservation capability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent segments the resource reservation process into two distinct phases: network resource reservation using standard RSVP protocol, and RF channel reservation using extended RSVP messages. This segmentation allows each phase to use appropriate protocols independently, resolving the contradiction between maintaining standard protocol compatibility and adding RF channel reservation capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary mechanism (extended RSVP messages with specific objects) that acts as a bridge between the standard RSVP protocol and the RF channel reservation requirement. This intermediary allows the M-CMTS core to communicate RF channel reservation requests through the existing RSVP infrastructure without modifying intermediary devices.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the resource reservation protocol is extended to include RF channel parameters, then RF channel reservation capability is achieved, but compatibility with existing intermediary devices is lost

Engineering Contradiction:

ImproveRF channel reservation capabilityVSAvoidinteroperability with existing systems

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent extracts RF channel-specific parameters into separate, optional objects within the RSVP message structure. These extracted parameters are included only when RF channel reservation is needed, allowing the core RSVP protocol to remain unchanged and compatible with existing devices while enabling extended functionality when required.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent implements partial extension of the RSVP protocol by adding optional RF channel parameter objects only when needed for RF channel reservation. This partial action approach maintains backward compatibility with existing devices that do not require RF channel reservation, while enabling the extended functionality for systems that do need it.

Inventive Principle:

Principle #16Partial or excessive action

3Adaptability or versatility

If intermediary devices are reconfigured to support RF channel reservation, then RF channel reservation capability is achieved, but system complexity and reconfiguration requirements increase

Engineering Contradiction:

ImproveRF channel reservation capabilityVSAvoidintermediary device configuration

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent enables the M-CMTS core to perform RF channel reservation autonomously by extending its own RSVP message generation capability. The core directly formulates and sends extended RSVP messages containing RF channel parameters to the EQAM, eliminating the need for intermediary devices to be reconfigured or to understand RF channel reservation details.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS8089983B2Reserving resources over a DOCSIS downstream external physical interface

Publication Date: 2012.01.03 CISCO TECHNOLOGY INC

AI summary

In one example, a resource reservation protocol is modified to allow a Modular Cable Modem Termination System (M-CMTS) core to use the protocol to reserve, for a flow, network resources as well as a Radio Frequency (RF) channel extending from the remote PHYsical interface (PHY). The modifications allow the M-CMTS core to identify parameters to be used by the edge device for selecting an available RF channel to be reserved for the flow, or to request a particular one of the RF channels. Intermediary devices operating on the DEPI can also reserve resources for the flow without being reconfigured according to the protocol modifications.