MME eDRX Configuration for MTC Battery Life
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Solution Overview
Problem
In cellular networks, particularly 3GPP LTE systems, Machine Type Communications (MTC) devices face challenges with extended battery life due to their low computational power and limited power for communication, as they often remain stationary and send small amounts of data infrequently, necessitating an efficient power-saving mode to maintain them in a low-power idle state for extended periods.
Innovation Solution
The implementation of an extended Discontinuous Reception (eDRX) mode in LTE networks, which allows MTC devices to remain in a low-power idle state for extended periods by configuring superframes and superframe numbers, enabling them to conserve battery life without frequent wake-ups for paging occasions, and potentially combining this with Power Saving Mode (PSM) to further reduce power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If MTC devices use traditional DRX mode, then they can maintain connectivity with the network, but their battery life is depleted quickly due to frequent wake-ups for paging occasions
Solution Approach 1:
The patent implements extended DRX by significantly increasing the DRX cycle length from traditional values (e.g., 1.28 seconds) to extended values (e.g., 10.24 seconds or longer), creating a periodic wake-up pattern that reduces energy consumption while maintaining network connectivity. The MTC UE wakes up at predetermined intervals to monitor paging occasions, then returns to sleep mode, applying periodic action to balance connectivity and power saving.
Solution Approach 2:
The patent changes key DRX parameters including the DRX cycle length, paging occasion timing, and inactivity timer values to optimize for extended power saving. By adjusting these parameters, the system enables MTC UEs to remain in idle mode for extended periods (up to several minutes) while still being reachable for downlink traffic, directly addressing the contradiction between battery life and connectivity.
2Speed
If MTC devices wake up frequently to monitor paging occasions, then they can receive downlink traffic promptly, but power consumption increases significantly
Solution Approach 1:
The patent applies periodic action by establishing extended DRX cycles where MTC UEs monitor paging occasions at predetermined intervals rather than continuously. The UE wakes up periodically to check for downlink traffic, then returns to low-power mode. This periodic monitoring reduces power consumption while still enabling timely reception of downlink traffic within each extended cycle period.
Solution Approach 2:
The patent implements dynamic behavior by allowing the MTC UE to adapt its wake-up pattern based on network conditions and traffic requirements. The extended DRX mechanism dynamically adjusts the balance between monitoring frequency and power saving, enabling the device to remain responsive to downlink traffic while optimizing power consumption through flexible timing of wake-up events.
3Use of energy by moving object
If MTC devices remain in idle mode for extended periods, then battery life is extended, but the devices become unavailable for downlink traffic
Solution Approach 1:
The patent resolves this contradiction by implementing periodic wake-ups within extended DRX cycles. The MTC UE remains in idle mode for most of the extended period to conserve battery, but periodically wakes up at predetermined paging occasions to check for downlink traffic. This periodic action ensures the device remains available for network communication at specific intervals while maximizing battery life during the intervals between wake-ups.
Data Source
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AI summary
Devices and methods of enabling simultaneous use of power saving mode (PSM) and a request extended Discontinuous Reception (eDRX) mode by user equipment (UE) are generally described. A mobility management entity (MME) may receive a request active timer (AT) and a request eDRX cycle time (eCT). The MME may store a UE-specific paging timer larger than the request eCT. Otherwise the MME may set a response AT and response eCT equal to the request AT and request eCT when the request AT is greater than a predetermined number of eDRX cycles. The MME may set the response AT less than the request AT and/or the response eCT less than the request eCT, or: the response AT less than the request AT and use a DRX cycle time or the response AT to be the request AT and the response eCT less than the request eCT.