Composite Channel Partitioning for Simultaneous Wireless Transmission
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Solution Overview
Problem
In wireless communication networks using the 802.11ac standard, single antenna devices face inefficiencies due to noise or interference on composite channels, leading to reduced bandwidth utilization, as existing methods fail to effectively allocate unused sub-channels for simultaneous transmission by multiple stations.
Innovation Solution
A method for reserving transmission opportunities (TXOP) in wireless communication networks, where a first station sends a request control frame (RTS) and receives a response control frame (CTS) to partition composite channels into non-overlapping subsets, allowing simultaneous data transmission from multiple stations on respective subsets, thereby optimizing channel allocation and reducing the need for repeated RTS/CTS sequences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single station reserves a composite channel for transmission, then the station can achieve high throughput on contiguous channels, but unused sub-channels due to noise or interference remain wasted bandwidth that cannot be utilized by other stations
Solution Approach 1:
The patent segments the composite channel into multiple non-overlapping subsets of sub-channels. When a first station reserves a composite channel, the remaining unused sub-channels are divided into subsets that can be independently allocated to other stations. This segmentation allows partial utilization of the composite channel even when some sub-channels are affected by noise or interference, thereby reducing wasted bandwidth and improving overall bandwidth utilization.
2Productivity
If multiple stations transmit simultaneously on the same composite channel, then channel utilization improves, but collision and interference increase under traditional CSMA/CA mechanisms
Solution Approach 1:
The patent divides the composite channel into non-overlapping subsets and allocates different subsets to different stations for simultaneous transmission. This frequency-division-like approach within the composite channel allows multiple stations to transmit without colliding, as each station uses a distinct subset of sub-channels. The segmentation principle thus enables improved channel utilization while maintaining transmission reliability by avoiding collisions.
Solution Approach 2:
The patent introduces a coordination mechanism where the first station that reserves the composite channel acts as an intermediary by allocating unused sub-channel subsets to other stations. This intermediary allocation process, communicated through control frames, ensures that multiple stations can transmit simultaneously on different subsets without collision, mediating between the need for high channel utilization and transmission reliability.
3Reliability
If traditional RTS/CTS reservation is used for each transmission, then collision avoidance is achieved, but the overhead of repeated sequences reduces transmission efficiency
Solution Approach 1:
The patent implements preliminary action by having the first station perform a single RTS/CTS reservation sequence to secure the entire composite channel. Once reserved, the first station can allocate unused sub-channel subsets to other stations without requiring each of them to perform separate RTS/CTS sequences. This preliminary reservation action reduces the repeated overhead of collision avoidance procedures while maintaining reliability, as the initial reservation establishes the framework for multiple simultaneous transmissions.
Solution Approach 2:
The patent merges multiple transmission opportunities into a single reserved transmission opportunity (TXOP). Instead of requiring separate RTS/CTS sequences for each station's transmission, the first station's single reservation secures the composite channel for multiple stations to transmit simultaneously on different subsets. This merging of multiple transmission requests into one reservation process reduces the time overhead associated with repeated RTS/CTS sequences while maintaining collision avoidance.
Data Source
AI summary
The invention relates to a method and system for simultaneous transmission of data from two or more wireless communication device during a transmission opportunity otherwise reserved for a single communication device. The invention proposes collaboration among the group of communication devices to reserve a transmission opportunity on a composite channel comprising of a plurality of sub-channels for the entire group and to efficiently manage allocation of the sub-channels for simultaneous data transmission from two or more devices. In the main aspect of the invention, the collaboration takes the form of grouping the sub-channels in the reserved composite channel so as to allow two or more stations to transmit data simultaneously over a contiguous frequency band. The collaboration among the group of communication devices may be in a managed or an ad hoc mode. The invention is particularly relevant to the IEEE 802.11 ac communication standard.