Roaming IMS Emergency Call Routing via P-CSCF Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing VoLTE systems face operational challenges in providing accurate and efficient emergency call connections for roaming users, particularly in international scenarios, due to connection delays and global emergency number management issues.
Innovation Solution
A communication apparatus and method that includes a reception unit for session establishment requests, a control unit to access databases for emergency number information based on the visited network's MCC and MNC, and a transmission unit to respond with rejection messages for unsupported emergency sessions, allowing the terminal to switch to alternative call domains like CS for connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the terminal transmits an IMS emergency call through the home network in a roaming situation, then the emergency call can be connected to the PSAP, but connection delays occur and the emergency number may not be supported in the visited network
Solution Approach 1:
The P-CSCF performs preliminary detection of whether the terminal is in a roaming situation and whether the visited network supports the emergency number before the emergency call is fully established. This early detection allows the system to prepare alternative routing paths in advance, avoiding connection delays by pre-identifying potential routing issues and switching to appropriate PSAPs in the visited network.
2Adaptability or versatility
If the terminal uses the home network's IMS for emergency calls while roaming, then the call can be routed through the home network, but the emergency number may not be supported in the visited network
Solution Approach 1:
The P-CSCF acts as an intermediary that detects roaming situations and coordinates between the home network and visited network. It queries the visited network to determine support for the emergency number, and based on this information, selects an appropriate PSAP. This intermediary function enables adaptive routing that ensures reliable emergency number support by leveraging local network capabilities in the visited network while maintaining home network control.
3Adaptability or versatility
If the system allows IMS emergency calls in roaming situations, then global emergency service access is enabled, but connection delays and unsupported emergency numbers occur
Solution Approach 1:
The system implements a feedback mechanism where the P-CSCF continuously monitors terminal location and network support status. When the terminal moves to a visited network, the P-CSCF detects this change, queries the visited network for emergency number support, and dynamically adjusts the routing path. This real-time feedback ensures that emergency calls are routed through networks that support the required emergency numbers, preventing connection delays and ensuring successful emergency service access globally.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention provides a communication apparatus that allows a call from a roaming destination to be connected accurately and efficiently according to a location where a subscriber is located. A communication apparatus includes a location information acquisition unit that acquires location information of a terminal, a reception unit that receives a call request transmitted by the terminal, a service identification unit that identifies a service of the request based on the location information of the terminal and a destination telephone number of the request, and a transmission unit that transmits a response to the terminal, when the service corresponding to the request cannot be provided.