NAV Timer Update Mechanism for Directional mmWave Networks
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Solution Overview
Problem
In directional mmWave communication systems, existing NAV timer configurations are not optimal for updating channel reservation times as they do not account for multiple simultaneous transmissions from different stations, leading to potential interference and inefficiencies in channel usage.
Innovation Solution
A method and apparatus for updating NAV timers in wireless communication systems that involve multiple stations by comparing source and destination addresses in received frames, allowing for the identification and management of multiple NAV values to ensure accurate channel reservation times, even in scenarios with directional antennas and multiple simultaneous transmissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single NAV Timer is used in omnidirectional communication, then the device complexity is reduced, but the measurement precision of channel reservation time is insufficient for directional communication with multiple STAs
Solution Approach 1:
The patent divides the single NAV Timer into multiple NAV Timers, with each timer dedicated to tracking channel reservation time for a specific STA. This segmentation allows precise tracking of multiple simultaneous transmissions without requiring a single complex timer that would need to handle all STAs indiscriminately, thus resolving the contradiction between device complexity and measurement precision.
Solution Approach 2:
Each NAV Timer is assigned specific local quality characteristics by associating it with particular source and destination address pairs. This allows each timer to have specialized functionality for its designated STA communication pair, improving measurement precision for channel reservation time while keeping each individual timer's complexity manageable through clear functional separation.
2Measurement precision
If multiple NAV Timers are implemented to track multiple simultaneous transmissions, then the measurement precision of channel reservation time is improved, but the device complexity increases
Solution Approach 1:
The patent implements a universal NAV Timer management mechanism that can handle multiple STAs through a standardized addressing scheme. Each NAV Timer uses the same structural design with source and destination address pairs, allowing the system to scale to multiple STAs without requiring fundamentally different timer architectures. This multi-functionality approach improves measurement precision while controlling device complexity through reuse of proven components.
Solution Approach 2:
The system performs preliminary action by pre-allocating and identifying NAV Timers based on source and destination address pairs before simultaneous transmissions occur. This proactive assignment of timers to specific STA pairs allows the system to handle multiple transmissions efficiently from the outset, improving measurement precision while avoiding the complexity of dynamic timer allocation and management during active communication.
3Productivity
If directional antennas are used to improve communication directionality, then the productivity of channel usage is improved, but the reliability of channel reservation detection is reduced due to inability to detect all transmissions
Solution Approach 1:
The patent adds another dimension to channel detection by incorporating both spatial dimension (directional antenna beams) and address dimension (source and destination address pairs). This multi-dimensional approach allows directional antennas to maintain their productivity benefits while the address-based NAV Timer system compensates for limited detection coverage, ensuring reliable channel reservation tracking even for transmissions outside the current beam direction.
Data Source
AI summary
In a 60 Hz WGA wireless network, not all frames with the duration field are received by a STA in a WGA network because of directional antennas. Therefore, a NAV Timer cannot account for the reserved duration of the channel by only updating with the longest duration field received. A STA can receive two frames each with a source and destination addresses and update the NAV Timer by comparing the received addresses to overcome such problem. Further, a STA can receive one frame with a source and destination addresses and update the NAV Timer by comparing the received addresses with the NAVSRC and NAVDST values.