Bi-Casting Handover for Continuous Downlink Data Delivery
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Solution Overview
Problem
Conventional handover technologies in wireless communication introduce delays in downlink data transmission due to data forwarding from a source base station to a target base station, leading to increased end-to-end delays and reduced quality of service, especially for time-sensitive services like industrial control and autonomous driving.
Innovation Solution
Implementing a bi-casting mode during handover, where the core network sends the same downlink service data packets to both the source and target base stations, and synchronizing the access stratum data packet sequence numbers to ensure seamless data continuity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If data is forwarded from source base station to target base station during handover, then data transmission continuity is ensured, but end-to-end delay increases
Solution Approach 1:
The core network performs preliminary actions by pre-establishing data transmission paths to both source and target base stations before handover completion. This allows the target base station to receive data directly from the core network in advance, eliminating the need for post-handover data forwarding and reducing end-to-end delay while ensuring transmission continuity.
Solution Approach 2:
The core network acts as an intermediary by implementing bi-casting functionality. It receives data from the data network and simultaneously forwards copies to both source and target base stations, eliminating the need for the source base station to forward data to the target base station, thus reducing delay while ensuring continuity.
2Loss of time
If bi-casting is implemented to reduce forwarding delay, then end-to-end delay decreases, but network data transmission load increases
Solution Approach 1:
The system implements partial bi-casting by selectively enabling direct core network transmission to the target base station only when necessary (during handover scenarios). This partial application of bi-casting reduces forwarding delay for critical handover data without continuously doubling the network load for all data transmissions, thus balancing delay reduction with energy efficiency.
Data Source
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AI summary
This application provides a communication method, user equipment, a base station, a core network device, and a communication system. The communication system includes a first base station, a second base station, and a core network. In the communication system, the first base station is configured to send a first request message to the core network, where the first request message is for requesting to send a data packet in a bi-casting mode, and the bi-casting mode is a transmission mode in which the core network sends a same data packet to each of the first base station and the second base station. The core network is configured to: after receiving the first request message, send one or more data packets to the first base station and the second base station in the bi-casting mode.