Wireless Frame Indicator Bits for Hidden Node Collision Avoidance
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Solution Overview
Problem
In wireless communication systems, devices can become 'hidden nodes' due to range limitations or obstructions, leading to collisions and packet losses as they cannot detect transmissions from other devices, causing performance degradation in systems relying on monitoring and sensing data from these devices.
Innovation Solution
A wireless communication device can determine frame exchanges between hidden nodes by analyzing speed frame indicator bits within received frames, allowing it to infer when the hidden node is transmitting and avoid collisions by determining the communication medium's status.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If devices transmit data without monitoring the communication medium, then transmission speed increases, but collision probability increases causing packet loss
Solution Approach 1:
The patent applies preliminary action by having devices check frame indicator bits in advance before transmitting data. The receiving device sets speed frame indicator bits (such as AckInd bits in PHY header or MD bit in MAC header) to indicate the status of the communication medium based on previously received frames. This allows the transmitting device to determine in advance whether the medium is likely available, preventing collisions before they occur while maintaining high transmission speeds.
2Reliability
If devices monitor all transmissions to avoid collisions, then collision probability decreases, but system complexity increases
Solution Approach 1:
The patent extracts only the essential information needed for collision avoidance by using specific frame indicator bits (AckInd bits or MD bit) from received frames. Instead of monitoring all transmission details, devices only need to check these extracted bits to determine medium availability. This significantly reduces monitoring complexity while maintaining reliable collision avoidance.
3Productivity
If hidden nodes transmit without detection capability, then transmission opportunity increases, but collision probability increases
Solution Approach 1:
The patent introduces frame indicator bits as an intermediary that conveys medium status information from the receiving device to potential hidden node transmitters. The receiving device sets these bits (AckInd or MD) based on whether it has received frames from hidden nodes, effectively mediating the hidden node's awareness of medium occupancy without requiring direct detection capability.
Data Source
AI summary
A signaling protocol allows for speed frame exchange between different wireless communication devices within single user, multiple user, multiple access, and/or MIMO wireless communication system. A listening wireless communication device analyzes state of speed frame indicator bits within frames transmitted from a first other wireless communication device to determine the entire radio frame exchanges between that first other wireless communication device and a second other wireless communication device. The second other wireless communication device may be a hidden node relative to the listening wireless communication device such that all or less than all transmissions from the hidden node are received by the listening device. The listening wireless communication device determines the status of the communication medium (e.g., the air in the context of a wireless communication system), so that it can transmit successfully without interfering with any ongoing communications between the first and second other wireless communication devices.