Target Access Network Device Packet Buffering During Handover

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

During the handover of a terminal between access network devices, the differing transmission times of packets through multiple channels can result in packet disorder at the terminal, as the end identification packets may not be received in a timely manner by the target access network device, leading to incomplete data transmission on one channel before packets are sent through another channel.

Innovation Solution

The target access network device buffers packets received from the source access network device and sends them to the terminal only after receiving end identification packets from both the core network device and the local routing device, or initiates a timer to ensure timely delivery of buffered packets if end identification packets are not received within a preset period.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If packets are transmitted through multiple channels during handover, then data transmission continuity is improved, but packet order is disrupted due to different transmission times

Engineering Contradiction:
Improvedata transmission continuityVSAvoidpacket order
Core Design Contradiction:
Duration of action of stationary objectVSManufacturing precision

Solution Approach 1:

The target access network device performs preliminary buffering of packets received from the source access network device before the handover is complete. By storing these packets in advance and releasing them only after confirming the handover status through end identification packets, the system ensures packets are transmitted in correct order while maintaining continuity across the transition period.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The target access network device acts as an intermediary between the source access network device and the terminal. It receives packets from the source, buffers them temporarily, and releases them in the correct sequence after verifying handover completion, thereby mediating the packet flow to prevent disorder while maintaining transmission continuity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If packets are buffered until end identification packets are received, then packet order is maintained, but transmission delay increases

Engineering Contradiction:
Improvepacket orderVSAvoidtransmission delay
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The system uses end identification packets as feedback signals to determine when buffering should be released. The target access network device monitors for these feedback packets from both the core network device and local routing device, and only releases buffered packets when the feedback confirms handover completion, thereby balancing order maintenance with timely delivery.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system buffers packets partially - only those received from the source access network device during the handover transition period. Once end identification packets confirm handover completion, the buffering action is stopped and packets are released, avoiding excessive buffering delays while still maintaining packet order for the critical transition period.

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If end identification packets are waited for from both core network device and local routing device, then complete data transmission is ensured, but handover completion time is extended

Engineering Contradiction:
Improvecomplete data transmissionVSAvoidhandover completion time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The target access network device performs preliminary buffering of packets during the handover process, preparing them for release once handover completion is confirmed. This preliminary action ensures that when packets are released, they are ready for immediate transmission in the correct order, maintaining reliability without extending the actual handover completion time.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses end identification packets as feedback mechanisms to confirm that data transmission from both the core network device and local routing device has been completed. By monitoring these feedback signals, the system ensures complete data transmission while using the feedback to trigger timely release of buffered packets, balancing reliability with handover speed.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3579617B1Preventing disorder of packets during handover
Publication Date: 2023.08.23 HUAWEI TECH CO LTD
  • EP3579617B1 patent drawingFigure 1~2
  • EP3579617B1 patent drawingFigure 3
  • EP3579617B1 patent drawingFigure 4

AI summary

Embodiments of the present invention provide a communication method and an apparatus. The communication method includes: receiving, by a target access network device, at least one first packet of a terminal when the terminal is handed over from a source access network device to the target access network device; buffering, by the target access network device, the at least one first packet; and sending the at least one buffered first packet to the terminal when the target access network device receives a second packet and a third packet from the source access network device, or the target access network device receives one of the second packet and the third packet and does not receive the other one of the second packet and the third packet within a preset period, or the target access network device does not receive the second packet or the third packet within the preset period, where the second packet and the third packet are end identification packets. In the embodiments of the present invention, disorder of packets received by a terminal can be avoided.