Fast Dormancy Signaling for UE Power Reduction
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Solution Overview
Problem
In LTE networks, User Equipment (UE) often maintains connected mode even when there is no data activity, leading to increased power consumption and reduced battery life due to unnecessary uplink transmissions and resource usage.
Innovation Solution
Implementing a Fast Dormancy (FD) procedure that allows the UE to proactively transition from connected mode to idle mode by sending an indication to the network, releasing unnecessary radio resources and reducing power consumption, using either RRC or MAC layer signaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the UE maintains connected mode to ensure immediate data transmission capability, then the network responsiveness is improved, but the power consumption increases and battery life is reduced
Solution Approach 1:
The system dynamically transitions the UE between connected mode and idle mode based on data activity conditions. The Fast Dormancy mechanism enables the UE to switch from connected mode to idle mode when no data activity is detected, and return to connected mode when data needs to be transmitted, optimizing the balance between network responsiveness and power consumption.
Solution Approach 2:
The network employs periodic inactivity timers to monitor data activity on the UE. When the timer expires without detecting data transmission, the network triggers the Fast Dormancy procedure to transition the UE to idle mode. This periodic monitoring enables the system to respond to changing data activity patterns while managing power consumption effectively.
2Productivity
If the UE remains in connected mode, then the radio resource allocation is maintained for quick data transmission, but unnecessary resource usage increases network overhead
Solution Approach 1:
The Fast Dormancy mechanism extracts the UE from connected mode and moves it to idle mode when data activity ceases. This separation removes the UE from the network's active resource allocation structures, eliminating unnecessary uplink resource usage and reducing network overhead while preserving the ability to quickly re-establish connection when needed.
3Device complexity
If the network uses traditional inactivity-based connection release, then the implementation is simple, but the transition time from connected to idle mode is prolonged
Solution Approach 1:
The UE proactively initiates the Fast Dormancy procedure by sending a Fast Dormancy Indication message to the network when it determines that no data activity will occur. This preliminary action allows the network to immediately begin the connection release process, significantly reducing the transition time from connected to idle mode compared to waiting for traditional inactivity timers to expire.
Solution Approach 2:
The Fast Dormancy mechanism introduces feedback from the UE to the network regarding data activity status. The UE monitors its own data activity and provides feedback through the Fast Dormancy Indication message, enabling the network to make informed decisions about connection maintenance or release, thereby optimizing the transition timing.
Data Source
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AI summary
A method performed by a network element, the method comprising transmitting, from the network element to a user equipment, UE, a fast dormancy, FD, configuration comprising an indication that the UE is permitted to send an FD indication and a value for an inhibit timer, wherein the FD indication indicates a request by the UE for a more energy efficient state or mode, the FD indication is for a specific radio bearer or bearers, or resource or resources, assigned to the UE that corresponds to a background type or interactive type, and the inhibit timer value represents a time duration during which the UE is prevented from sending a subsequent request for the more energy efficient state or mode; and receiving the FD indication from the UE based on the FD configuration.