Serving Node Relocation via SCEF Notification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication systems face challenges in smoothly relocating a serving node during mobile terminated calls, especially when handling non-IP data, as they often require querying the home subscriber server for routing information, leading to increased signaling overhead and potential call loss.
Innovation Solution
The method involves transmitting a context request message to the new serving node to retrieve the UE context, determining the configuration of non-IP data transmission, and notifying the Service Capability Exposure Function (SCEF) of the relocation, allowing the SCEF to acknowledge and manage the update without querying the home subscriber server for routing information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the system queries the home subscriber server for routing information during serving node relocation, then the serving node can be relocated, but signaling overhead increases
Solution Approach 1:
The SCEF is pre-notified of the serving node relocation before the relocation is complete. The new serving node's address is provided to the SCEF in advance through an update location message, allowing the SCEF to prepare for future data transmission without requiring a query to the HSS at the time of relocation.
Solution Approach 2:
The SCEF acts as an intermediary that maintains the mapping between the UE's external identifier and the current serving node address. By updating this mapping proactively through the update location message, the system avoids the need for the SCEF to query the HSS later, thereby reducing signaling overhead while ensuring reliable data delivery.
2Reliability
If the system queries the home subscriber server for routing information during mobile terminated calls, then routing can be established, but call loss may occur
Solution Approach 1:
The SCEF is proactively updated with the new serving node address before mobile terminated data arrives. This preliminary update ensures that when data needs to be delivered to the UE, the SCEF already has the correct routing information, eliminating delays and preventing call loss that would occur if a query to the HSS were needed at that moment.
3Reliability
If the SCEF recognizes the latest serving node, then mobile terminated calls are seamless, but additional notification mechanisms are required
Solution Approach 1:
The update location notification function is merged with the existing serving node relocation procedure. The update location message is sent as part of the normal relocation process, combining the address update function with the existing mobility management workflow rather than adding a completely separate notification mechanism.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed are a serving node relocating method in a wireless communication system and a device for same. In detail, a method for relocating, by a first serving node, a serving node in a wireless communication system can include: receiving a tracking area update (TAU) request message from a terminal; transmitting an update location request to a home subscriber server (HSS), when the first serving node having received the TAU request message is different from a second serving node that is an old node; and transmitting an update location message to a service capability exposure function (SCEF), when the first serving node is different from the second serving node that is the old node and a connection for transmitting/receiving non-internet protocol (non-IP) data via the SCEF is configured in the terminal.