TAU-less PSM D2D Resource Allocation for Emergency Uplink
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Solution Overview
Problem
Current wireless communication systems face challenges in enabling V2X terminals to perform uplink transmissions efficiently in a TAU-less Power Saving Mode (PSM) after being switched off, as they require complex detachment and re-attachment procedures, which hinder prompt emergency notifications.
Innovation Solution
The method involves an MME transmitting a TAU accept message that allocates a D2D resource to the UE, allowing it to perform uplink transmissions without periodic TAU procedures, even when switched off, and deleting the UE context after the TAU accept message is sent, enabling efficient management of TAU-less PSM.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE performs periodic TAU procedures to maintain connection, then the connection stability is improved, but the power consumption increases and the response time for emergency notifications increases
Solution Approach 1:
The network performs preliminary actions by allocating D2D resources and configuring TAU-less PSM parameters before the UE enters power saving mode. The MME sends TAU accept messages with D2D resource allocation information to the UE, enabling the UE to perform emergency notifications without requiring periodic TAU procedures. This preliminary configuration allows the UE to maintain connection capability while in power saving mode, resolving the contradiction between connection stability and response time.
2Use of energy by moving object
If the UE enters PSM mode to save power, then the power consumption is reduced, but the ability to perform uplink transmissions is limited
Solution Approach 1:
The patent introduces D2D (device-to-device) communication as an intermediary mechanism that enables uplink transmissions without requiring traditional network-based TAU procedures. The MME allocates D2D resources to the UE in advance, allowing the UE to directly transmit emergency notifications to nearby devices or infrastructure without going through conventional network signaling. This intermediary D2D mechanism resolves the contradiction by enabling power saving while maintaining uplink transmission capability through an alternative communication path.
Solution Approach 2:
The patent changes the operational parameters of the UE by configuring TAU-less PSM mode with specific parameters including D2D resource allocation, periodic TAU timer configuration, and detachment conditions. The MME sends TAU accept messages containing these parameter changes to the UE, allowing the UE to operate in a modified power saving mode that preserves uplink transmission capability through parameter modification rather than complete mode change.
3Speed
If the network maintains UE context to enable quick reconnection, then the reconnection speed is improved, but the network resource consumption increases
Solution Approach 1:
The patent extracts the essential reconnection information from the full UE context by using TAU accept messages that contain only the necessary parameters for quick reconnection. The MME sends extracted reconnection information (including D2D resource allocation and TAU configuration) to the UE without maintaining the complete UE context in the network. This extraction approach enables fast reconnection while minimizing network resource consumption by storing only essential reconnection parameters rather than full context.
Solution Approach 2:
The patent implements a mechanism where the network discards detailed UE context after sending TAU accept messages with necessary reconnection information. The UE recovers and uses this extracted information to perform quick reconnection when needed. The network can discard context to save resources while the UE retains the necessary reconnection parameters locally, enabling the discard-and-recover cycle that balances reconnection speed with network resource consumption.
Data Source
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AI summary
An embodiment of the present invention relates to a method for receiving and transmitting, by a mobility management entity (MME), tracking area update (TAU)-less power saving mode (PSM) related signals, the method comprising the steps of: receiving, from a terminal, a first TAU request message including information related to a TAU-less PSM entity; transmitting a TAU accept message in response to the first TAU request message; and receiving a second TAU request message including information related to release of the TAU-less PSM, wherein the second TAU request message including information related to release of the TAU-less PSM is regarded by the MME as an attach request.