Link-Aware Clear Channel Assessment for Wireless Parallel Transmissions
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Solution Overview
Problem
Existing Clear Channel Assessment (CCA) rules in wireless networks often lead to unnecessarily high signal-to-interference-plus-noise ratio (SINR) when devices are close or inadequate protection when far apart, preventing parallel/simultaneous transmissions that could succeed.
Innovation Solution
The introduction of new CCA rules that utilize additional fields in the preamble or MAC header of Physical Layer Convergence Procedure (PLCP) Protocol Data Units (PPDU) or Media Access Control (MAC) headers to protect initiator and responder transmissions, ensuring adequate SINR by transmitting compressed receiver identity and expected power information, allowing for more parallel/simultaneous transmissions without interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing CCA rules are used, then channel access is simplified, but SINR protection is inadequate for devices far apart
Solution Approach 1:
The patent applies preliminary action by having the initiator transmit additional fields in the preamble before the actual data transmission begins. These fields contain receiver identity information and expected power levels that enable third devices to perform link-aware CCA assessments in advance, determining whether to defer or proceed with their own transmissions before interference occurs.
Solution Approach 2:
The patent introduces intermediary elements in the form of additional preamble fields that act as mediators between devices. These fields carry compressed receiver identity and expected power information, serving as an intermediary mechanism that enables third devices to assess link conditions without requiring direct communication between initiator and responder, thus resolving the complexity-reliability contradiction.
2Productivity
If existing CCA rules are used, then device complexity is low, but parallel transmissions are prevented when they could succeed
Solution Approach 1:
The patent enables parallel transmissions through preliminary action by having the initiator include additional fields in the preamble that convey receiver identity and expected power information. This allows third devices to perform link-aware CCA assessments before the data transmission begins, determining whether they can safely transmit in parallel without causing interference, thereby increasing productivity.
Solution Approach 2:
The patent implements feedback mechanisms where the initiator provides information about the intended transmission (receiver identity, expected power) in the preamble. This feedback enables third devices to make informed decisions about whether to proceed with parallel transmissions, optimizing channel utilization while maintaining reliability through link-aware assessments.
3Reliability
If additional fields are added to preamble/MAC header, then link-aware CCA is enabled, but header size increases
Solution Approach 1:
The patent applies the extraction principle by isolating the essential CCA information into separate additional fields within the preamble structure. These fields contain only the necessary compressed receiver identity and expected power information, extracting the critical data needed for link-aware CCA while keeping the overall header structure organized and manageable, thus minimizing the length increase.
Solution Approach 2:
The patent applies local quality by adding additional fields only in specific locations where they are most effective for CCA functionality. The compressed receiver identity and expected power information are placed in the preamble where they can be processed by third devices during CCA assessments, providing localized enhancement of reliability without unnecessarily expanding the entire header structure.
Data Source
AI summary
A pair of Clear Channel Assessment (CCA) rules are presented that protect an initiator's transmission at the responder, and the responder's transmission at the initiator, using additional fields transmitted in a preamble (header) of a Physical Layer Convergence Procedure (PLCP) Protocol Data Unit (PPDU) or in a Media Access Control (MAC) header, if unencrypted and robustly modulated. These techniques enable more parallel/simultaneous transmissions between devices that might otherwise interfere with each other, subject to ensuring an adequate Signal-to-Interface and-Noise Ratio (SINR) for the initiator's transmission at the responder and ensuring an adequate SINR for the responder's transmission at the initiator.