LTE to GERAN Handover via Temporary Tunnels and PS Attach
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge lies in supporting seamless handover between LTE/EUTRAN and GERAN wireless communication systems, as their differing architectures and network configurations complicate the process of transferring a mobile unit's connection between these systems without data loss or service interruption.
Innovation Solution
A method and apparatus for handover from LTE/EUTRAN to GERAN, involving packet switched (PS) attach signals and RAN mobility information messages exchanged between the WTRU and the target base station controller, along with temporary tunnel establishment to ensure continuous data transfer during the transition, allowing for efficient handover procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If handover between LTE/EUTRAN and GERAN systems is implemented, then service continuity is improved, but device complexity increases due to different architectures and protocols
Solution Approach 1:
The patent introduces a target base station controller (T-BSC) as an intermediary entity that receives RAN mobility information from the source eNodeB and coordinates the handover process. This intermediary simplifies the interaction between LTE and GERAN systems by providing a standardized interface, thereby reducing overall system complexity while maintaining service continuity during handover.
2Productivity
If RAN mobility information messages are exchanged during handover, then handover efficiency is improved, but information loss risk increases due to architecture differences
Solution Approach 1:
The patent performs preliminary actions by establishing temporary tunnels and exchanging RAN mobility information messages before the actual handover execution. The source eNodeB sends RAN mobility information to the T-BSC in advance, allowing the target system to prepare necessary resources and ensure data forwarding paths are ready, thereby preventing information loss while maintaining efficient handover.
3Reliability
If temporary tunnels are established for data transfer during handover, then data continuity is improved, but device complexity increases
Solution Approach 1:
The patent extracts the tunnel management function from the user equipment and centralizes it in the network infrastructure (source eNodeB, T-BSC, and target GERAN components). By moving the complexity of temporary tunnel establishment and management to the network side, the user equipment's complexity is reduced while data continuity is maintained through properly managed temporary data forwarding tunnels.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method and apparatus for handover of a dual mode wireless transmit/receive unit (WTRU) from an LTE system to a GERAN system uses measurements of the LTE and GERAN frequencies and a decision by a source evolved Node B to perform the handover. A GERAN access procedure includes PS attach messages exchanged between the WTRU and the target base station controller and a target SGSN. Alternatively, the GERAN access procedure uses RAN mobility information messages exchanged by the WTRU and the target base station controller and a relocation detect message by the source evolved Node B.