LTE Signal Mode Switching for NC-to-CE Coverage Handover
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Solution Overview
Problem
Existing LTE technologies fail to actively switch terminal devices from Normal Coverage (NC) to Coverage Enhanced (CE) mode when signal strength deteriorates, resulting in passive and ineffective mode transitions.
Innovation Solution
A method and terminal device for actively switching between NC and CE modes by receiving control instructions, additional broadcast information elements, and uplink transmission resources to ensure synchronized mode transitions, utilizing Radio Resource Control (RRC) signaling and enhanced Machine Type Communication (eMTC) configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the terminal device uses existing LTE technology for network access, then the terminal device can operate in Normal Coverage (NC) mode with standard signal transmission, but the terminal device cannot actively switch to Coverage Enhanced (CE) mode when signal strength deteriorates, resulting in passive and ineffective mode transitions
Solution Approach 1:
The base station performs preliminary actions by sending control instruction information to the terminal device before the terminal device needs to switch modes. The control instruction includes RRC configuration information and indications to read eMTC broadcast information, preparing the terminal device for active mode switching before signal deterioration becomes critical.
Solution Approach 2:
The patent introduces an intermediary mechanism through control instruction information that mediates between the base station and terminal device for mode switching. This intermediary contains RRC signaling and eMTC broadcast information indicators, enabling the terminal device to actively switch from NC to CE mode based on base station instructions rather than passively waiting for signal failure.
2Reliability
If the terminal device passively switches to CE mode based on downlink signal strength, then the terminal device can maintain network access in weak coverage areas, but the switching process causes service interruption and delays
Solution Approach 1:
The base station sends control instruction information in advance that includes RRC configuration information and indications for reading eMTC broadcast information. This preliminary action allows the terminal device to prepare for mode switching before actual signal deterioration occurs, reducing service interruption time when switching to CE mode.
Solution Approach 2:
The patent implements feedback mechanisms where the terminal device reads eMTC broadcast information and sends uplink transmission responses to the base station. This feedback loop allows the terminal device to confirm successful mode switching and receive further instructions, minimizing service interruption by maintaining communication continuity during the transition.
3Adaptability or versatility
If the base station sends control instruction information to actively switch the terminal device to CE mode, then the mode switching becomes active and timely, but the terminal device must read additional eMTC broadcast information increasing processing complexity
Solution Approach 1:
The patent applies universality by integrating eMTC broadcast information reading into the existing LTE broadcast reception process. The control instruction information includes indications that leverage the terminal device's existing broadcast reception capabilities, allowing it to read eMTC broadcast information using the same mechanisms already employed for LTE broadcasts, thereby reducing additional processing complexity.
Solution Approach 2:
The patent merges the eMTC broadcast information reading process with the existing LTE broadcast reception process. By combining these functions and using unified control instruction information that includes both RRC configuration and eMTC broadcast indications, the terminal device processes both broadcast types through a single integrated mechanism, reducing overall processing complexity despite the added functionality.
Data Source
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AI summary
Embodiments of the present invention relate to a signal transmission mode switching method. The method includes: when it is detected that signal transmission with a terminal device is abnormal, sending, to the terminal device, control instruction information used to configure a signal transmission mode; and switching a current signal transmission mode to a to-be-switched-to signal transmission mode. The terminal device obtains, in a plurality of manners, a broadcast corresponding to the signal transmission mode to be switched to; determines, based on the broadcast information, configuration information of the to-be-switched-to signal transmission mode; configures the to-be-switched-to signal transmission mode based on the configuration information; and then switches the current signal transmission mode to the to-be-switched-to signal transmission mode. A base station and the terminal device separately switch, in an agreed time period, the current signal transmission mode to the to-be-switched-to signal transmission mode, to avoid a problem of cognitive inconsistency between the base station and the terminal device about a transmission mode.