TDLS Power Save Mode Synchronization in WLAN
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In WLAN systems based on IEEE 802.11a/b/g standards, non-AP stations cannot establish a Direct Link Setup (DLS) directly due to APs not supporting IEEE 802.11e, limiting the utilization of Power Save Mode (PSM) through APs, and there is a need for effective management of PSM under Tunneled Direct Link Setup (TDLS) for power conservation.
Innovation Solution
A method and apparatus for establishing a TDLS direct link between peer stations, including transmitting a PSM request frame with a wakeup schedule via an access point or directly, and receiving a PSM response frame to manage power save mode, which reduces power consumption by synchronizing wakeup schedules and handling rejections or alternative schedules.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If non-AP stations use traditional AP-based Power Save Mode management, then power consumption can be reduced, but direct communication between stations cannot be established when AP does not support IEEE 802.11e
Solution Approach 1:
The patent uses the Access Point as an intermediary to establish TDLS direct links between non-AP stations. The AP facilitates the initial link setup and coordination, but once established, direct communication occurs between stations without continuous AP involvement, enabling both power save mode and direct link functionality.
Solution Approach 2:
The patent segments the power management functionality into two parts: AP-based power save mode for general power management, and TDLS direct links for specific direct communication needs. This allows stations to use the most efficient path for each type of communication.
2Adaptability or versatility
If stations establish TDLS direct links for direct communication, then adaptability is improved, but power save mode management becomes complex without AP support
Solution Approach 1:
The patent makes the Access Point serve multiple functions: it acts as both a traditional power management coordinator and a facilitator for TDLS direct link establishment. This multi-functionality simplifies the overall system by keeping power management centralized at the AP even when direct links are used.
Solution Approach 2:
The patent implements feedback mechanisms where stations report their power save mode status and wakeup schedules to the AP, which then coordinates TDLS link establishment accordingly. This feedback loop allows the AP to manage power save mode complexity centrally while enabling direct links.
3Reliability
If stations remain in awake state for direct communication, then communication reliability is improved, but power consumption increases
Solution Approach 1:
The patent implements periodic wakeup schedules where stations alternate between sleep and awake states. During awake periods, stations can reliably communicate via TDLS direct links. This periodic action reduces power consumption while maintaining communication reliability when needed.
Solution Approach 2:
The patent uses preliminary action by establishing TDLS direct links and coordinating wakeup schedules in advance through the AP. This allows stations to know when to wake up for communication, ensuring reliability while minimizing the time spent in awake state and reducing overall power consumption.
Data Source
AI summary
A method and apparatus of a power save mode in a wireless local area network is disclosed. A station transmits a power save mode (PSM) request frame including a wakeup schedule for the PSM to the peer station via an access point (AP) or via a Tunneled Direct link Setup (TDLS) direct link. The station receives a PSM response frame in response to to the PSM request frame from the peer station via the TDLS direct link.