Uplink Synchronization via Polling to Reduce WTRU Battery Power
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, maintaining uplink synchronization while reducing battery power consumption is a challenge, especially in active states where conventional methods consume significant power.
Innovation Solution
A Node-B sends a polling message to a WTRU for contention-free uplink synchronization, estimating and adjusting timing without frequent contention, and allowing the WTRU to enter an idle state during cell reselection, thereby reducing power consumption through discontinuous reception modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a WTRU maintains uplink synchronization frequently using conventional methods (RACH transmissions), then uplink synchronization is maintained, but battery power consumption increases
Solution Approach 1:
The patent implements periodic uplink synchronization bursts at predetermined intervals instead of continuous or frequent synchronization attempts. The WTRU transmits uplink synchronization bursts periodically based on a predetermined periodicity, which maintains synchronization reliability while significantly reducing the frequency of transmissions and associated power consumption compared to conventional RACH-based methods.
Solution Approach 2:
The network pre-configures the WTRU with uplink synchronization parameters including periodicity, time offsets, and resource allocations before the WTRU enters idle state. This preliminary configuration allows the WTRU to perform synchronized transmissions without needing to contend for resources or establish connections first, reducing power consumption by eliminating unnecessary contention and setup procedures.
2Reliability
If a WTRU performs handover to maintain connectivity during cell movement, then connectivity is maintained, but power consumption increases due to handover signaling
Solution Approach 1:
The patent introduces a new idle state that dynamically bridges the gap between cells during movement. When a WTRU moves between cells while in idle state, it can perform cell reselection and transmit synchronization bursts to the new cell without executing a full handover procedure. This dynamic state allows the WTRU to adapt to cell changes while avoiding the power-intensive handover signaling and radio bearer reconfiguration.
Solution Approach 2:
The patent extracts the essential synchronization function from the complete handover procedure. By allowing WTRUs in idle state to perform cell reselection and transmit synchronization bursts to new cells without full handover, the system separates the critical synchronization capability from the power-consuming handover signaling and radio bearer management, enabling movement with minimal power expenditure.
3Use of energy by moving object
If a WTRU enters idle state to save power, then battery consumption is reduced, but uplink synchronization may be lost
Solution Approach 1:
The patent ensures continuous uplink synchronization capability even in idle state by configuring periodic uplink synchronization bursts with predetermined periodicity. The WTRU maintains this continuous synchronization action while in idle state, transmitting bursts at configured intervals without needing to transition to active state, thereby preserving both power savings and synchronization reliability simultaneously.
Data Source
AI summary
A Node-B sends a polling message to a wireless transmit/receive unit (WTRU). The WTRU sends an uplink synchronization burst in response to the polling message without contention. The Node-B estimates an uplink timing shift based on the synchronization burst and sends an uplink timing adjustment command to the WTRU. The WTRU then adjusts uplink timing based on the uplink timing adjustment command. Alternatively, the Node-B may send a scheduling message for uplink synchronization to the WTRU. The WTRU may send a synchronization burst based on the scheduling message. Alternatively, the WTRU may perform contention-based uplink synchronization after receiving a synchronization request from the Node-B. The WTRU may enter an idle state instead of performing a handover to a new cell when the WTRU moves to the new cell. A discontinuous reception (DRX) interval for the WTRU may be set based on activity of the WTRU.