Cellular Network Distributing Wi-Fi NAV to Resolve Hidden Node Collisions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wi-Fi networks face inefficiencies due to the hidden node problem, where stations are unaware of interfering nodes, leading to collisions and increased retransmissions, especially in dense environments.
Innovation Solution
Distributing Network Allocation Vectors (NAV) using LTE, LTE-Advanced, or SG New Radio signaling to Wi-Fi stations, mapping NAV to OFDM symbols, allowing stations to identify channel availability and schedule usage without interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If Wi-Fi stations use carrier sense multiple access with collision avoidance, then channel access is simplified, but hidden nodes cause collisions and spectrum inefficiency
Solution Approach 1:
The patent introduces an intermediary mechanism where the cellular network acts as a mediator to distribute NAV information to Wi-Fi stations. The base station receives NAV updates from the Wi-Fi network and forwards them to relevant UEs, enabling stations to sense channel usage indirectly through cellular signaling rather than direct carrier sensing, thereby resolving the hidden node problem while maintaining operational simplicity
Solution Approach 2:
The system implements feedback by continuously updating NAV information through cellular network signaling. The base station receives NAV status information from Wi-Fi access points and transmits updates to connected UEs, creating a closed-loop feedback mechanism that keeps all stations informed of channel usage status, eliminating collisions caused by hidden nodes
2Device complexity
If stations transmit without knowing channel usage by hidden nodes, then transmission simplicity is maintained, but collisions and retransmissions increase
Solution Approach 1:
The patent applies preliminary action by having stations set their NAV counters in advance based on predicted channel usage information received from the cellular network. Before a station transmits, it has already been informed of potential channel occupancy by hidden nodes through NAV updates, allowing it to preemptively delay transmission and avoid collisions, thereby improving reliability without adding transmission complexity
3Adaptability or versatility
If Wi-Fi operates in unlicensed spectrum without centralized coordination, then deployment flexibility is improved, but spectrum utilization becomes inefficient
Solution Approach 1:
The patent achieves universality by enabling the cellular network infrastructure to serve dual purposes: its primary function for cellular communication and an additional function of distributing NAV information to manage Wi-Fi spectrum access. This multi-functional approach allows the cellular network to coordinate Wi-Fi traffic in unlicensed spectrum, improving spectrum utilization efficiency while preserving deployment flexibility
Data Source
AI summary
A device of a User Equipment (UE), a method to operate the device, and a machine readable medium. The device includes processing circuitry and a radio frequency (RF) interface coupled to the processing circuitry, the processing circuitry to: decode a signal sent in a cellular network from a base station (BS), the signal including a network allocation vector (NAV) information update regarding a NAV corresponding to a Wi-Fi network, the NAV to be set by a Wi-Fi station (STA) that is in the Wi-Fi network, and that is to be coupled to the UE via a connection; and send the NAV information update to the STA by way of the connection to allow the STA to set its NAV in the Wi-Fi network based on the NAV information update.