Channel Frame Structures for HEW Uplink Scheduling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current IEEE 802.11 Wireless LAN systems face inefficiencies in channel access and scheduling for uplink multi-user transmissions in unlicensed frequency bands, particularly in ensuring fair access for both HEW and legacy stations, due to the lack of guaranteed channel ownership and synchronization in these bands.
Innovation Solution
The implementation of a scheduling mechanism and frame exchange sequences that allocate specific time slots and subchannels to HEW stations, allowing them to transmit data without contention, while also providing fair access opportunities for legacy stations by using a combination of contention-based and scheduled channel access methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If contention-based channel access is used in unlicensed bands, then legacy stations can access the channel, but channel access becomes inefficient and unsynchronized
Solution Approach 1:
The channel access mechanism is segmented into two distinct parts: a contention-based portion for legacy station access and a scheduled portion for HEW station access. This segmentation allows each type of station to use the access method best suited to its capabilities, improving overall efficiency while maintaining legacy compatibility
Solution Approach 2:
A scheduled access mechanism acts as an intermediary between HEW stations and the channel, mediating their access to prevent contention while still allowing legacy stations to use traditional contention-based methods. The scheduler coordinates resource allocation to avoid conflicts between the two access methods
2Productivity
If scheduled channel access is implemented for HEW stations, then channel access efficiency improves, but the complexity of channel access control increases
Solution Approach 1:
Channel resources are preliminarily allocated through scheduling decisions made by the access point before actual transmission occurs. This preliminary action organizes uplink transmissions in advance, preventing contention and improving efficiency without requiring complex real-time coordination during actual data transmission
Solution Approach 2:
The scheduled access mechanism operates periodically with defined time slots and frames, creating a predictable and rhythmic access pattern. This periodic structure simplifies the control logic compared to continuous contention resolution, as stations can anticipate their next access opportunity based on the established schedule
Data Source
AI summary
An high efficiency wireless local area network access point including a channel access module and a scheduling module. The channel access module accesses a channel of an unlicensed frequency band, which includes a plurality of subchannels. The scheduling module generates a schedule for a plurality of high efficiency wireless local area network client stations to transmit data to the access point via the channel of the unlicensed frequency band. The schedule includes information for the plurality of client stations regarding (i) a time slot in which to access the channel without contention to transmit data to the access point via the channel, (ii) a subchannel of the plurality of subchannels to use during the time slot to transmit data to the access point, and (iii) one or more spatial streams to use on the subchannel and during the time slot to transmit data to the access point.