HSDPA Multi-Flow Handover via Level 1 Signaling
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Solution Overview
Problem
In multi-flow HSDPA wireless telecommunications networks, handover processes between cells are hindered by fast fading, which can lead to insufficient time for level 3 messaging to configure user equipment with target and assisting base stations, requiring significant resource allocation for preconfiguration, especially when multiple carriers are involved.
Innovation Solution
A method where a level 1 message from the target base station directly instructs user equipment to handover, indicating whether to maintain or discard assisting serving cells and providing revised subframe pairings, allowing handover without preconfiguration of assisting cells, thus reducing resource requirements and minimizing the risk of connection loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If level 3 messaging is used to configure user equipment with target and assisting base stations during handover, then configuration accuracy is improved, but handover time increases and connection stability deteriorates due to fast fading
Solution Approach 1:
The patent applies preliminary action by pre-configuring the user equipment with assistance information from the target base station before the handover is actually executed. The level 1 message from the target base station includes pre-configured assistance information that the UE can immediately use when handover is triggered, eliminating the need for time-consuming level 3 messaging during the handover process itself. This resolves the contradiction by preparing configuration data in advance so that the actual handover can occur rapidly without compromising configuration accuracy.
2Reliability
If preconfiguration information is stored for multiple potential serving and assisting base stations, then handover reliability is improved, but device complexity and resource consumption increase
Solution Approach 1:
The patent applies the extraction principle by removing the requirement for user equipment to store and process preconfiguration information for multiple potential assisting base stations. Instead, the assistance information is extracted and provided directly by the target base station through level 1 messaging at the time of handover. This eliminates the need for complex preconfiguration storage and management in the UE, reducing device complexity while maintaining handover reliability through on-demand provision of necessary configuration data.
3Manufacturing precision
If subframe pairings are preconfigured for all potential serving and assisting cell combinations, then handover precision is improved, but resource consumption increases
Solution Approach 1:
The patent applies preliminary action by pre-calculating and including the specific subframe pairing information in the level 1 message from the target base station before handover execution. Rather than requiring the UE to have pre-configured subframe pairings for all possible cell combinations, the necessary subframe pairing information is prepared in advance by the network and transmitted to the UE at the appropriate time. This resolves the contradiction by providing precise subframe pairing information on-demand, eliminating the need for extensive preconfiguration resources in the UE while maintaining handover precision.
Data Source
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AI summary
Methods of initiating handover, a base station, a network control node, user equipment and a computer program product are disclosed. The method of initiating handover between cells of a High-Speed Downlink Packet Access wireless telecommunications network where user equipment receives a data stream on a common frequency from both a serving cell and at least one assisting serving cell comprises: in response to a received message from a controlling network node identifying that a change in serving cell is required, transmitting a level 1 message from a target serving base station supporting a target serving cell to the user equipment instructing the user equipment to handover to the target serving cell and indicating to the user equipment whether to continue to utilise each of the at least one assisting serving cell. Such an approach enables the handover to occur. Also, by reusing existing cells, the need for a preconfiguration of the user equipment with configuration for the assisting serving cells is obviated.