Roaming Emergency Call Handling via Visited Network Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In roaming scenarios without local breakout, telecommunications networks face significant operational costs and complexity in maintaining a database of emergency numbers for all roaming partners, as user equipment is unaware of valid emergency call numbers in visited networks, leading to inefficient emergency call handling.
Innovation Solution
A method where the user equipment initiates a voice call with a specific emergency call number, which is detected by the visited network's telephone number detecting node, and communicates this information to the home network, allowing the home network to trigger an emergency call procedure without relying on user equipment implementation or maintaining a large database of emergency numbers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the home telecommunications network maintains a database of emergency numbers for all roaming partners, then emergency call handling reliability is improved, but operational costs and device complexity increase significantly
Solution Approach 1:
The patent extracts the emergency number database functionality from the home network and relocates it to the visited network. The visited network's telephone number detecting node maintains and provides emergency numbers locally, eliminating the need for the home network to maintain a comprehensive database of all roaming partners' emergency numbers while ensuring reliable emergency call handling.
Solution Approach 2:
The patent introduces an intermediary mechanism where the visited network's telephone number detecting node acts as a mediator between the user equipment and the emergency services. This node detects emergency call attempts, provides the appropriate emergency number to the home network's proxy functionality, and enables successful routing without requiring the home network to directly maintain emergency number databases.
2Measurement precision
If the user equipment is provisioned with emergency numbers from the visited network, then emergency call detection accuracy is improved, but user equipment provisioning complexity and loss of information increase
Solution Approach 1:
The patent implements preliminary action by having the visited network's telephone number detecting node prepare and provide emergency number information to the home network's proxy functionality before the user equipment needs to place an emergency call. This ensures the proxy has the necessary information to detect and route emergency calls correctly without requiring advance provisioning of the user equipment.
Solution Approach 2:
The patent enables the visited network's telephone number detecting node to self-serve by automatically detecting when a user equipment is attempting to place an emergency call and providing the appropriate emergency number information to the home network's proxy functionality, eliminating the need for manual provisioning or user equipment to maintain emergency number lists.
3Speed
If local breakout is used in the roaming scenario, then emergency call handling speed is improved, but network architecture complexity increases
Solution Approach 1:
The patent applies universality by enabling the home network's proxy functionality to handle both regular calls and emergency calls through a unified mechanism. The proxy functionality detects emergency calls using emergency number information provided by the visited network's telephone number detecting node and routes them appropriately, eliminating the need for separate local breakout architecture while maintaining efficient emergency call handling.
Data Source
Figure 1~2
AI summary
The invention relates to a method for improved handling of emergency calls in a roaming scenario, wherein a user equipment is assigned to a home telecommunications network and wherein the user equipment is connected to a visited telecommunications network, wherein the proxy functionality of the home telecommunications network is used in the roaming scenario, wherein an voice call is initiated by the user equipment using a specific emergency call telephone number being a valid emergency call telephone number in the visited telecommunications network, wherein the user equipment initially handles the voice call-involving the specific emergency call telephone number as a normal voice call (non-UE detected emergency call), wherein the method comprises the steps of: in a first step, the voice call is initiated by the user equipment by means of the user equipment transmitting a first message directed to a network node of the home telecommunications network, the first message comprising the specific emergency call telephone number, wherein the specific emergency call telephone number is detected by a telephone number detecting network node of the visited telecommunications network, in a second step, subsequent to the first step, a second message is transmitted to the network node home telecommunications network, the second message comprising an emergency call information, the emergency call information being indicative of the use of a valid emergency call telephone number in relation of the voice call, in a third step, subsequent to the second step, a third message is generated by the node of the home telecommunications network, the third message being directed to the user equipment, wherein the third message is transmitted to a network node of the visited telecommunications network, and forwarded, as a fourth message, to the user equipment, the third and fourth messages comprising an indication, to the user equipment, to trigger an emergency call procedure towards the visited telecommunications network by means of a fifth message.