WWAN Backup Link for IP Centrex Signaling Resilience

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

IP Centrex systems face disruptions when the landline connection between the enterprise network and the IP WAN fails, causing both internal and external call setups to be unavailable, as the signaling path is lost, leading to service outages and potential communication breakdowns.

Innovation Solution

Implementing a wireless WAN (WWAN) backup link, such as a cellular packet-data link, to enable continued packet-based call setup signaling between the enterprise network and the IP WAN, allowing the system to switch to the WWAN connection upon landline failure and maintain call setup functionality within the enterprise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If IP Centrex service is implemented to reduce installation cost and simplify network infrastructure, then installation cost and complexity are reduced, but reliability deteriorates because the system becomes vulnerable to landline connection failures

Engineering Contradiction:

Improveinstallation costVSAvoidservice availability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The system pre-configures a backup WWAN connection before the landline failure occurs. The backup link is established in advance with appropriate routing and signaling parameters, so that when the primary landline connection fails, the system can immediately switch to the pre-prepared backup path without delay in service restoration

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention implements a redundant WWAN communication path as a protective measure against landline connection failures. This backup infrastructure acts as a cushion that absorbs the impact of primary connection failures, ensuring continuous service availability and preventing complete system outage

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Device complexity

If a single landline connection is used for packet-based signaling between enterprise network and IP Centrex server, then device complexity is reduced, but reliability worsens because any landline failure causes complete service outage

Engineering Contradiction:

Improvenetwork infrastructureVSAvoidcall setup availability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The system dynamically changes the communication parameter (transmission medium) from landline-based signaling to WWAN-based signaling when the landline connection fails. This parameter change allows the system to adapt to different operational conditions and maintain service through alternative physical layers

Inventive Principle:

Principle #35Parameter changes

3Reliability

If WWAN backup link is implemented to maintain signaling capability during landline failures, then reliability is improved, but device complexity increases due to additional backup infrastructure

Engineering Contradiction:

Improveservice continuityVSAvoidnetwork infrastructure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The WWAN connection acts as an intermediary communication path between the enterprise network and the IP Centrex server. When the primary landline connection is unavailable, this intermediary channel facilitates continued signaling operations, enabling the system to maintain functionality through an alternative communication medium

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS7508754B1Method and system to support internal calling upon loss of connection with IP Centrex server

Publication Date: 2009.03.24 SPRINT SPECTRUM LP

AI summary

A method and system for facilitating calling within an enterprise network upon failure of a landline connection between the enterprise network and an outside call server such as an IP Centrex server. Upon failure of the landline connection, an enterprise router switches over to a backup wireless packet-data link, such as a 3G cellular link for instance. Thus, packet-based call signaling can continue to flow between the enterprise network and the call server so as to continue setting up inside calls between enterprise telephone stations. The backup wireless packet-data link can also be used to carry a limited extent of outside calls, such as emergency calls for instance.