PDN Synchronization via Timer-Based Retransmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In LTE and 5G networks, synchronization issues between user equipment (UE) and network entities lead to PDN state mismatches, causing users to be unable to use data services until they perform specific actions like airplane mode ON/OFF or switching off the UE.
Innovation Solution
The system and method involve transmitting PDN disconnect requests from the UE to the network, initiating timers, and re-transmitting requests if no response is received. This process includes deactivating EPS Bearer Contexts and storing relevant IDs and parameters to synchronize UE and network states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the network accepts the PDN DISCONNECT REQUEST but delays sending the response due to resource issues or request overflow, then the network processing load is reduced temporarily, but the PDN synchronization state between UE and network deteriorates
Solution Approach 1:
The UE stores the PTI and EPS bearer identity before initiating the disconnection procedure. When the timer expires and the UE re-transmits the PDN DISCONNECT REQUEST, it uses the stored parameters to maintain consistency. This preliminary storage action enables the UE to handle network delays without losing synchronization state.
Solution Approach 2:
The system implements a timer-based feedback mechanism where the UE monitors the network's response to PDN DISCONNECT REQUEST. When the timer T3492 expires without receiving a response, the UE re-transmits the request with the same stored PTI and bearer identity, creating a feedback loop that maintains synchronization despite network delays.
2Stability of the object's composition
If the UE re-transmits the PDN DISCONNECT REQUEST with the same PTI when timer T3492 expires, then the PDN disconnection procedure is maintained consistently, but the network may reject the re-transmitted request with cause 'PTI already in use'
Solution Approach 1:
The UE performs preliminary storage of the PTI and EPS bearer identity before the network processes the disconnection request. This stored information is retained and re-used when the timer expires, ensuring the UE maintains a consistent view of the disconnection procedure even if the network has already processed the original request.
Solution Approach 2:
The system prepares for potential network rejection by storing the original request parameters in advance. When the network rejects the re-transmitted request with 'PTI already in use', the UE has already deactivated the EPS bearer context locally, cushioning against the rejection and maintaining procedural stability.
3Ease of operation
If the UE deactivates the EPS Bearer Context locally upon receiving PDN DISCONNECT REJECT, then the UE can recover from the rejection, but the network and UE enter an unsynchronized state preventing data services
Solution Approach 1:
The UE stores the PTI and EPS bearer identity before the disconnection procedure begins. This stored information allows the UE to correctly identify and deactivate the appropriate bearer context when recovering from rejection, ensuring the UE operates independently without requiring real-time network synchronization.
Solution Approach 2:
The UE performs self-service by deactivating the EPS bearer context locally when it receives a PDN DISCONNECT REJECT message. This self-service action allows the UE to recover from the rejection and maintain operational capability without requiring further network intervention, though it creates a synchronization gap with the network.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The invention provides methods and system for optimizing PDN synchronization between a user equipment and a network. The method comprises processing, by a user equipment, a deactivate request based on a stored set of parameters. The method further encompasses transmitting, from the user equipment to the network entity, a deactivate accept based on said processing, wherein said transmission of deactivate accept enables said network entity to deactivate a connectivity between the user equipment and the network entity to synchronize the user equipment with said network entity.