Access Point Hidden Node Interference Reduction
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Solution Overview
Problem
Existing solutions to the hidden node problem in wireless communication networks often result in throughput reduction due to added overhead and latency, and there is a need for methods that minimize these effects.
Innovation Solution
An access point in a wireless communication network receives position signals from mobile terminals, partitions them into groups based on distance metrics, and allocates separate frequency resources to each group to minimize hidden node interference, using techniques like beam forming and positioning signals to determine terminal positions without requiring extensive measurement information from terminals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If RTS/CTS procedure is used to address hidden node problem, then collision probability is reduced, but overhead and latency increase
Solution Approach 1:
The patent replaces the mechanical RTS/CTS handshake procedure with a virtual coordinate-based scheduling system. The access point assigns virtual coordinates to terminals based on their spatial positions, and uses these coordinates to schedule transmissions without requiring actual RTS/CTS exchanges between hidden nodes. This substitution eliminates the time-consuming handshake while maintaining collision avoidance through coordinated scheduling.
Solution Approach 2:
The access point performs preliminary positioning and coordinate assignment for all terminals before data transmission begins. By pre-establishing the spatial relationships and assigning appropriate virtual coordinates, the system prepares the scheduling information in advance, eliminating the need for real-time RTS/CTS negotiations and reducing latency.
2Reliability
If adjacent terminal information is transmitted through new frequency band, then hidden node detection is enabled, but overhead information increases
Solution Approach 1:
The patent extracts only the essential positioning information (coordinates) from the complex adjacent terminal measurement data. Instead of transmitting detailed measurement information about adjacent terminals, the system extracts and transmits only the simplified virtual coordinates that capture the essential spatial relationship needed for hidden node detection and scheduling.
Solution Approach 2:
The patent transforms the complex adjacent terminal measurement parameters into simplified virtual coordinate parameters. By changing the parameter representation from detailed measurement data to compact coordinate values, the system maintains the ability to detect hidden nodes while significantly reducing the amount of information that needs to be transmitted.
3Reliability
If position-based grouping is performed, then hidden node interference is reduced, but device complexity increases
Solution Approach 1:
The patent replaces complex real-time position calculation and dynamic grouping mechanisms with a simpler virtual coordinate assignment system. The access point assigns virtual coordinates based on pre-determined spatial relationships, and scheduling is performed using these coordinates without requiring continuous position tracking or complex grouping algorithms, thereby reducing device complexity while maintaining interference reduction benefits.
Data Source
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AI summary
A hidden node interference reduction method of an access point of a wireless communication network is disclosed, wherein the access point is adapted to serve a plurality of mobile terminals. The method comprises receiving a signal from at least two of the plurality of mobile terminals in response to transmitting the positioning signal, wherein each signal is indicative of a position of the respective mobile terminal. The method further comprises partitioning the plurality of mobile terminals into one or more groups by determining a metric for at least one pair of mobile terminals based on the indicated positions (wherein the pair of mobile terminals comprises a first mobile terminal and a second mobile terminal, and wherein the metric is associated with a distance between the first mobile terminal and the second mobile terminal of the pair of mobile terminals) and letting the first and second mobile terminals of the pair of mobile terminals belong to different groups if the metric fulfills a condition (wherein the condition is indicative of the first mobile terminal causing hidden node interference to the second mobile terminal). The method also comprises allocating a separate respective frequency resource to each group of mobile terminals. Corresponding computer program product, arrangement and access point are also disclosed.