AP Cooperation for Low Latency WLAN Interference Mitigation
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Solution Overview
Problem
Wireless communication networks, particularly IEEE 802.11 based WLANs, face significant latency and jitter issues due to the allocation of the same channel to multiple access points, leading to delays in multi-user OFDMA transmissions, which is disadvantageous for real-time applications in the industry safety domain.
Innovation Solution
An access point (AP) is configured to receive and process subsets of uplink packets from associated stations and overlapping basic service set (OBSS) APs, determining the complete set of packets based on signal quality and interference, allowing for improved time-sharing interference mitigation and reducing latency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the same channel is allocated to multiple access points to improve spectrum utilization, then channel utilization efficiency is improved, but transmission latency and jitter increase due to time-sharing interference
Solution Approach 1:
The patent merges the reception capabilities of multiple access points by having OBSS APs forward received uplink packets to the target AP. This combining of reception resources allows the network to effectively utilize the same channel for multiple APs while maintaining low latency, as packets are received by whichever AP gets them first and then forwarded to the destination, eliminating the need for strict time-sharing protocols.
2Productivity
If multi-user OFDMA transmission is used to increase network capacity, then network throughput is improved, but latency and jitter increase to 5 milliseconds or longer
Solution Approach 1:
The patent implements preliminary action by having OBSS APs proactively receive and forward uplink packets before the target AP would otherwise receive them. This preliminary reception and forwarding mechanism ensures that packets are already in the network path when needed, reducing latency while maintaining the high throughput benefits of OFDMA by allowing simultaneous transmissions across different spatial domains.
3Speed
If time-sharing interference mitigation is used to reduce latency, then transmission speed is improved, but network capacity is reduced due to channel allocation constraints
Solution Approach 1:
The patent transitions from two-dimensional channel time-sharing to three-dimensional spatial-multiplexing by utilizing the spatial dimension through multiple OBSS APs. This allows simultaneous transmissions on the same channel across different spatial locations, effectively increasing network capacity while maintaining fast transmission speeds through direct forwarding paths.
Data Source
AI summary
A first access point (AP) in a wireless local area network (WLAN) is configured to communicate with one or more non-AP stations associated with the first AP and at least one second AP. The first AP includes a communication interface configured to receive, from the one or more non-AP stations, a first subset of uplink packets transmitted by the one or more non-AP stations to the first AP and receive, from the at least one second AP, a second subset of the uplink packets transmitted by the one or more non-AP stations to the first AP. Moreover, the first AP comprises a processing circuitry configured to determine the uplink packets based on the first subset and the second subset.