Direct Link Power Save Coordination in Wireless Networks

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Solution Overview

Problem

Wireless communication systems face challenges in efficiently managing power save mechanisms during direct link set-ups, as mobile stations are not typically aware of their peers' sleep states, making it difficult to maintain power save modes while maintaining active direct data transfers.

Innovation Solution

The implementation of a direct link set-up (DLS) power save delivery mechanism that allows mobile stations to coordinate power management modes, enabling scheduled or unscheduled transitions between active and power save modes, with one station remaining awake to notify peers of availability for data transfers during power save modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If mobile stations enter power save mode during direct link set-up, then energy consumption is reduced, but data transfer coordination becomes difficult because stations are unaware of peer sleep states

Engineering Contradiction:
Improveenergy consumptionVSAvoiddata transfer coordination
Core Design Contradiction:
Use of energy by moving objectVSEase of operation

Solution Approach 1:

The patent applies preliminary action by having mobile stations exchange power save mode capability information and negotiate power save parameters before entering power save mode. This pre-coordination allows stations to know when their peers will be sleeping, enabling proper data transfer scheduling without continuous monitoring during sleep periods.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback mechanisms where mobile stations send power save mode notifications and data transfer requests to their peers. When a station wakes from power save mode, it can notify its peer, and when data needs to be transferred, the receiving station can signal its availability, creating a feedback loop that coordinates transfers despite power saving cycles.

Inventive Principle:
Principle #23Feedback

2Ease of operation

If mobile stations remain in active mode to maintain data transfer awareness, then data transfer coordination is improved, but energy consumption increases

Engineering Contradiction:
Improvedata transfer coordinationVSAvoidenergy consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent applies periodic action by having mobile stations alternate between active and power save modes based on negotiated schedules. Instead of remaining continuously active, stations wake at periodic intervals to check for data, perform transfers if needed, and return to sleep, reducing energy consumption while maintaining coordination through pre-established agreements about wake times and data availability.

Inventive Principle:
Principle #19Periodic action

3Use of energy by moving object

If power save mode is implemented without coordination awareness, then energy is conserved, but data transfer efficiency decreases due to missed transfers during sleep periods

Engineering Contradiction:
Improveenergy conservationVSAvoiddata transfer efficiency
Core Design Contradiction:
Use of energy by moving objectVSProductivity

Solution Approach 1:

The patent uses preliminary action by having stations negotiate and exchange power save mode parameters, capability information, and data transfer preferences before entering power save state. This advance coordination ensures that both stations know when the other will be available, preventing data loss and ensuring efficient transfer scheduling without requiring continuous monitoring during sleep periods.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2215873B1Power save by direct link
Publication Date: 2014.05.28 QUALCOMM INC
  • EP2215873B1 patent drawingFigure 1
  • EP2215873B1 patent drawingFigure 2
  • EP2215873B1 patent drawingFigure 3

AI summary

Systems and methodologies are described that enable power save mechanisms to be utilized with active direct transfers. Mobile stations (104, 106) in a wireless communication network (100) can establish direct links (114) between each other to obviate a need to transfer data via an access point (102). While direct links (114) are active, the mobile stations (104, 106) coordinate or otherwise notify each other about power management modes to effectuate power save delivery of data via direct links (114). In accordance with a scheduled mechanism, mobile stations (104, 106) coupled via a direct link (114) enter an active mode at a previously negotiated scheduled time after which time data transfer can occur. According to an unscheduled mechanism, one mobile station (104, 106) can remain awake while other enters a power save mode. The sleeping station can awaken and transmit a trigger frame to notify its peer that it is available for data transfers.