SMF Traffic Steering for Dedicated Network Access During Roaming
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Solution Overview
Problem
In existing communication systems like 4G and 5G, users cannot continue to access dedicated data networks when they leave the location where the traffic steering rules are preconfigured, leading to issues with traffic circumambulation and inefficient IP address allocation during cross-province/cross-city roaming.
Innovation Solution
A communication method and apparatus that enables session management at a visited location based on dedicated data network identifiers, allowing access to both public and dedicated networks, with traffic offloading at the visited location to avoid circumambulation, and includes dynamic traffic steering rules using IP address lists and domain name lists.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traffic steering rules are preconfigured on SMF or UPF at the location of the dedicated data network, then the user can access the dedicated data network at that location, but the user cannot continue to access the dedicated data network when leaving the location
Solution Approach 1:
The patent applies preliminary action by pre-establishing tunnel information and traffic steering rules at the visited location's SMF before the user actually moves there. The home SMF sends the user's IP address, dedicated data network identifier, and pre-configured traffic steering rules to the visited SMF in advance, so that when the user roams to the visited location, the traffic steering is already in place and can immediately forward packets to the dedicated data network without interruption.
Solution Approach 2:
The patent uses the visited location's SMF and UPF as intermediaries to maintain access to the dedicated data network. Instead of requiring direct connection between the user and the home location's network elements, the visited location's network elements act as mediators that receive traffic steering rules from the home SMF and handle packet forwarding locally, enabling seamless access while roaming.
2Reliability
If all user traffic is routed back to the home location for processing, then the user can access the dedicated data network, but traffic circumambulation occurs increasing latency and reducing efficiency
Solution Approach 1:
The patent extracts the traffic steering function from the home location and places it at the visited location. By sending only the necessary traffic steering rules and tunnel information from the home SMF to the visited SMF, the actual data traffic can be processed and forwarded locally at the visited location rather than being routed back to the home location, thus eliminating traffic circumambulation and reducing latency.
Solution Approach 2:
The patent changes the dimension of traffic handling by moving the traffic steering capability from a single location (home) to multiple locations (home and visited). This allows traffic to be processed in parallel at different geographic locations depending on where the user is, rather than forcing all traffic through a single centralized point, thereby reducing transmission time and improving efficiency.
3Reliability
If traffic steering rules are dynamically updated during roaming, then the user can maintain access to the dedicated data network, but the system complexity increases
Solution Approach 1:
The patent applies universality by making the SMF at the visited location multi-functional. The visited SMF not only handles local user sessions but also receives and executes traffic steering rules from the home SMF, manages tunnels to the dedicated data network, and performs IP address translation. This consolidates multiple functions into a single network element, reducing overall system complexity while maintaining continuous access during roaming.
Data Source
AI summary
This application relates to a communication method and apparatus. The method includes: A first SMF network element receives first information from a PCF network element, where the first information includes an identifier of a first dedicated data network to which a terminal device subscribes; the first SMF network element sends a first request including the identifier of the first dedicated data network to a second SMF network element that supports the first dedicated data network; the first SMF network element receives, from the second SMF network element, a first response including second tunnel information of a second UPF network element, where the second UPF network element is a UPF network element selected based on the first dedicated data network; and the first SMF network element sends second information to a first UPF network element, where the second information includes the second tunnel information and a first traffic steering rule.