Packet Scheduling for Mobile Subscriber Station Power Saving
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Solution Overview
Problem
Existing power saving mechanisms in broadband wireless networks, such as those defined by the IEEE 802.16e standard, are ineffective for mobile subscriber stations (MSS) with multiple connections, leading to high power consumption as they cannot optimize sleep intervals across different connections.
Innovation Solution
A packet scheduling method that aggregates unscheduled data bursts into frames based on individual packet delays, shifting data bursts to maximize the total time length of sleep intervals and minimize listen intervals, thereby enhancing power saving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the MSS uses existing power saving mechanisms (exponential growth, fixed, or long sleep intervals) for single connection, then power consumption is reduced, but these mechanisms become ineffective when the MSS has multiple connections with different sleep intervals, causing the MSS to always operate in high power consumption state
Solution Approach 1:
The patent merges multiple connections with different QoS requirements into a unified packet scheduling framework. It combines data bursts from multiple connections into aggregated frames, allowing the MSS to coordinate sleep intervals across all connections simultaneously rather than being constrained by individual connection requirements, thus enabling power saving in multi-connection scenarios
Solution Approach 2:
The patent introduces dynamic packet scheduling that adapts to varying QoS requirements of different connections. The system dynamically determines which data bursts to aggregate into frames and which to transmit separately, adjusting the scheduling strategy based on delay constraints and traffic patterns, thereby achieving both power efficiency and adaptability
2Use of energy by moving object
If the MSS aggregates all data bursts into frames to maximize sleep intervals, then power saving increases, but data transmission delay may increase for connections with strict delay constraints
Solution Approach 1:
The patent applies local quality by treating different connections differently based on their specific QoS requirements. Connections with strict delay constraints are handled with lower aggregation priority, allowing their data bursts to be transmitted more frequently, while connections with relaxed delay constraints are aggregated more aggressively to maximize power saving, thus balancing power efficiency and delay requirements locally for each connection
3Reliability
If the MSS frequently wakes up to check for data in listen intervals to ensure timely data transmission, then data transmission reliability is maintained, but power consumption increases
Solution Approach 1:
The patent performs preliminary action by pre-scheduling data bursts into frames before transmission. The base station and MSS coordinate in advance to determine which data bursts will be aggregated and their expected transmission timing, allowing the MSS to enter sleep mode with confidence that wake-ups are only needed when actually required, reducing unnecessary power consumption while maintaining reliability
Data Source
AI summary
Exemplary embodiments of the present disclosure provide several packet scheduling methods and communication apparatuses using the same. The packet scheduling method is different from the conventional packet scheduling method, since it does not schedule the sleep interval of the mobile subscriber station based upon the connections as the conventional packet scheduling method. Instead, the packet scheduling method considers the quality of service, and aggregates the data bursts to the frame corresponding to the frame index to which the data bursts are shifted based upon the individual packet, such that a total time length of the sleep intervals of the mobile subscriber station is maximized, and the maximum power saving efficiency is obtained correspondingly.