Satellite Uplink Management via Solicited and Unsolicited Grants
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Solution Overview
Problem
Traditional satellite uplink management techniques are inadequate for large networks with numerous user terminals, leading to congestion, reduced throughput, and increased latency due to inefficient resource allocation and contention for uplink resources.
Innovation Solution
A satellite uplink management system utilizing solicited and unsolicited grants of uplink resources, where user terminals employ short and long buffer data status messages and non-orthogonal multiple access to minimize latency and optimize resource usage, with a resource scheduler on the satellite determining communication resources based on scheduling input data and content provider information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional satellite uplink management techniques are used, then system simplicity is maintained, but uplink contention increases and throughput decreases
Solution Approach 1:
The patent segments uplink resource allocation into two distinct mechanisms: solicited grants (user-initiated requests) and unsolicited grants (satellite-initiated allocations). This segmentation allows the system to handle different traffic types efficiently - solicited grants for unpredictable user data and unsolicited grants for predictable periodic traffic - thereby increasing overall throughput without requiring complete redesign of the resource management system
Solution Approach 2:
The patent implements preliminary action through buffer status reporting and predictive scheduling. User terminals report buffer status in advance, allowing the satellite to predict future uplink needs and allocate resources proactively via unsolicited grants before actual data transmission is needed. This preliminary resource allocation reduces contention and improves throughput by eliminating waiting time
2Loss of time
If traditional uplink resource allocation is used, then system complexity is low, but latency increases due to contention
Solution Approach 1:
The system performs preliminary resource allocation through buffer status reports and predictive scheduling algorithms. The satellite receives buffer status information from user terminals and proactively allocates uplink resources before data needs to be transmitted. This preliminary action eliminates the traditional contention-based waiting time, significantly reducing uplink latency while the scheduling system manages multiple users efficiently
Solution Approach 2:
The patent introduces buffer status reports as an intermediary mechanism between user terminals and the satellite scheduler. These reports provide advance information about upcoming data transmissions, allowing the satellite to prepare resource allocations and reduce contention delays. The intermediary buffer status mechanism enables the scheduling system to anticipate needs and allocate resources timely, reducing latency without requiring complex real-time arbitration
3Quantity of substance
If more user terminals are added to the satellite network, then network coverage and service capacity improve, but uplink contention increases and resource allocation becomes less efficient
Solution Approach 1:
The patent segments the uplink resource pool into solicited and unsolicited grant categories, allowing efficient management of large numbers of user terminals. Unsolicited grants are allocated based on predictive scheduling for terminals with periodic traffic patterns, while solicited grants handle unpredictable data arrivals. This segmentation enables the system to scale to many users without proportionally increasing contention, as the scheduling system can efficiently allocate resources to multiple terminals simultaneously based on their different traffic characteristics
Solution Approach 2:
The patent changes the allocation parameter from reactive (granting resources only after user request) to proactive (predicting and allocating resources before need). By introducing buffer status reports and predictive scheduling, the system transforms resource allocation based on future needs rather than past requests. This parameter change allows efficient handling of many user terminals, as the satellite can allocate resources based on predicted traffic patterns rather than contending for randomly arrived requests
Data Source
AI summary
A satellite provides communication between user terminals (UTs) and ground stations that connect to other networks, such as the Internet. Because the satellite is within range of many UTs at any given time, many UTs are in contention to use an uplink to send upstream data to the satellite. This saturates a random-access channel (RACH) on the uplink. When a UT has data to uplink, it sends a short buffer data status (SBDS) message using the RACH. The minimal size of the SBDS facilitates use of a non-orthogonal multiple access uplink. Based on the SBDS, the satellite allocates a grant to the UT to use the uplink. Additional messages from the UT involving buffer status may be sent using the granted uplink. Unsolicited grants may be issued to the UT based on analysis of uplink and downlink traffic. If needed, the RACH may still be used to request additional grants.