IMS-TDM Interface Unit Eliminates Tromboning via Signaling Separation
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Solution Overview
Problem
The integration of Time Division Multiplexing (TDM) intelligent networks with Voice over Internet Protocol (VoIP) networks is hindered by 'tromboning' issues, where voice paths are excessively long, causing delays and echoes, and existing solutions like SS7 signaling do not effectively address these problems, leading to high costs and complexity in service deployment.
Innovation Solution
A method for connecting Internet Protocol Multimedia Subsystem (IMS) networks to TDM intelligent networks using an interface unit that processes call signaling, allowing IMS application servers to control TDM endpoints and eliminate tromboning by routing calls through a voice over internet gateway, thereby simplifying application development and reducing the need for dual-mode applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If centralized service switches are used to implement services in TDM networks, then service deployment flexibility is improved, but voice path length increases causing tromboning effects
Solution Approach 1:
The patent segments the service switching function from the voice bearer path. The centralized service switch (CSS) handles only signaling and service logic, while voice traffic is routed directly between endpoints through the network, avoiding the tromboning effect where voice would have to travel to and from the centralized switch.
Solution Approach 2:
The patent introduces an intermediary mechanism where the centralized service switch acts as a signaling intermediary rather than a voice traffic intermediary. It processes call setup, service logic, and control signaling while allowing voice bearers to take optimal direct paths through the network infrastructure.
2Extent of automation
If TDM centralized service switches process both signaling and voice bearers, then service control is improved, but network cost and complexity increase
Solution Approach 1:
The patent extracts the voice bearer processing function from the centralized service switch, leaving only signaling and service control functions. This separation eliminates the need for expensive TDM switching matrices in the CSS, reducing device complexity and cost while maintaining full service control capability.
Solution Approach 2:
The patent replaces the mechanical TDM switching matrix with a software-based service control architecture. Service logic is implemented as software modules that process signaling messages, eliminating the need for complex hardware switching matrices and reducing both cost and complexity.
3Adaptability or versatility
If dual-mode applications are developed for both TDM and IMS networks, then network compatibility is improved, but application development complexity increases
Solution Approach 1:
The patent creates a universal service switch architecture that can handle both TDM and IMS networks through a common service control platform. The CSS uses standardized protocols (SIGTRAN for TDM, SIP for IMS) to interface with different network types, allowing single applications to serve multiple network domains without requiring separate dual-mode implementations.
Data Source
AI summary
The present invention relates to a method in a communication network for connecting at least one application server (AS) (213) of an internet protocol multimedia subsystem (IMS) (200) to an intelligent network (IN) (100) through an interface unit (301). The IMS (200) comprises a call server control function (CSCF) unit (205) connected to the at least one AS (213) arranged for processing call signaling. In the method the interface unit (301) directs the call signaling to the at least one AS (213) through the CSCF unit (205) and the at least one AS (213) processes the call signaling and sends the processed call signaling through the CSCF unit (205) back to the interface unit (301). Based on the information received in the call signaling processed by the at least one AS (213), the interface unit (301) then directs the call to a destination.