Correlating Intercept Information with Call Content in S8HR VoLTE

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Solution Overview

Problem

Current technologies lack the capability to effectively correlate Intercept Related Information (IRI) with Call Content (CC) for lawful interception of voice services in the Visited Public Land Mobile Network (VPLMN) when using the S8 Home Routing (S8HR) VoLTE roaming architecture, as none of the network nodes involved in performing lawful interception reside in the VPLMN.

Innovation Solution

The method involves the Bearer Binding Intercept and Forwarding Function (BBIFF) forwarding IMS Signalling packets to the LI Mirror IMS State Function (LMISF), which performs deep packet inspection to determine if a call needs to be intercepted, and then delivers SIP messages and media packets to the appropriate entities for correlation and delivery to Law Enforcement Monitoring Facilities (LEMFs).

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If S8HR architecture is used for VoLTE roaming, then network efficiency and routing optimization are improved, but lawful interception capability is lost because no network nodes for lawful interception reside in the VPLMN

Engineering Contradiction:
Improvenetwork efficiencyVSAvoidlawful interception capability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent introduces intermediary functions (BBIFF, LMISF) that act as mediators between the S8HR architecture and lawful interception requirements. These intermediaries enable correlation of IRI and CC by forwarding and inspecting packets without disrupting the efficient S8HR routing path, thus maintaining network efficiency while restoring lawful interception capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If deep packet inspection is performed to identify calls for interception, then interception accuracy is improved, but network traffic processing complexity increases

Engineering Contradiction:
Improveinterception accuracyVSAvoidtraffic processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the lawful interception function into separate specialized components: BBIFF for packet forwarding and binding, LMISF for deep packet inspection and correlation, DF2 for IRI delivery, and DF3 for CC delivery. This segmentation allows each component to focus on a specific task, improving interception accuracy while distributing processing complexity across multiple dedicated functions rather than concentrating it in a single complex system.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3482542B1Methods and apparatuses for correlating intercept related information with call content
Publication Date: 2023.04.26 NOKIA SOLUTIONS & NETWORKS OY
  • EP3482542B1 patent drawingFigure 1
  • EP3482542B1 patent drawingFigure 2
  • EP3482542B1 patent drawingFigure 3

AI summary

Systems, methods, and apparatuses for correlating intercept related information (IRI) with call content (CC) for S8HR lawful interception are provided. The method may include generating at a network entity a correlation identifier. The method may also include adding the correlation identifier to a session initiation protocol message. In addition, the method may include delivering the session initiation protocol message including the correlation identifier from the network entity to another network entity.