Wireless Node Idle Interval for Hidden Node Collision Avoidance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, hidden wireless nodes can cause collisions due to non-immediate responder stations not initiating an idle interval after receiving a multi-user transmission, leading to potential interference with immediate response transmissions.
Innovation Solution
A wireless node starts an idle interval after receiving a multi-user transmission with a valid frame check sequence, ensuring sufficient time for an acknowledgment frame transmission, thereby avoiding collisions with other stations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If non-immediate responder stations do not initiate an idle interval after receiving multi-user transmission, then channel access efficiency is improved, but collisions occur with immediate response transmissions
Solution Approach 1:
The patent applies local quality by differentiating the behavior of immediate responder stations from non-immediate responder stations. Immediate responders are required to initiate an idle interval (EIFS) after receiving multi-user transmissions, while non-immediate responders do not. This localized differentiation resolves the contradiction by preventing collisions at the specific location where they occur (immediate responder transmissions) while maintaining high channel access efficiency for other stations.
2Reliability
If all stations initiate an idle interval after receiving multi-user transmission, then collision avoidance is improved, but channel access efficiency deteriorates
Solution Approach 1:
The patent avoids the inefficiency of universal idle interval initiation by applying local quality - only immediate responder stations initiate the idle interval. This targeted approach maintains collision avoidance where it is needed (at immediate responder transmissions) while allowing non-immediate responders to access the channel without unnecessary delays, thus preserving overall channel access efficiency.
3Object-affected harmful factors
If immediate responder stations initiate an idle interval, then interference with other stations is reduced, but transmission delay increases
Solution Approach 1:
The patent applies preliminary anti-action by having immediate responder stations initiate an idle interval (EIFS) before transmitting their acknowledgment frames. This preliminary action prevents potential collisions with other stations that might be transmitting simultaneously, thereby reducing interference. The idle interval acts as a preventive measure that eliminates the need for longer retry sequences, ultimately reducing overall transmission delay despite the initial waiting period.
Data Source
AI summary
Certain aspects of the present disclosure provide techniques and apparatus for starting an extended idle interval in an effort to avoid collisions with transmissions from hidden wireless nodes. One example apparatus generally includes a receiver and a processing system. The receiver is typically configured to receive a multi-user (MU) transmission comprising at least one packet for the apparatus. The processing system is typically configured to determine a checksum of the at least one packet and to start an idle interval associated with the apparatus after receiving the MU transmission if the at least one packet comprises a frame check sequence (FCS) that corresponds to the checksum, wherein the idle interval includes at least enough time for transmission of an acknowledgment (ACK) frame. For certain aspects, the idle interval may comprise an extended interframe space (EIFS).