Satellite Return Link Contention-Based Data Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Non-geosynchronous satellite communications experience significant data transmission delays, particularly for real-time data like voice and video, due to the need for explicit grants of scheduled return link resources, which introduce scheduling request opportunity delays, signal propagation delays, and processing delays.
Innovation Solution
User terminals in the satellite system are allowed to transmit data on contention-based resources before receiving a grant of scheduled return link resources, thereby reducing delays by avoiding the need for explicit scheduling requests and associated processing delays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If explicit grants of scheduled return link resources are used, then resource allocation reliability is improved, but data transmission delay increases
Solution Approach 1:
The system performs preliminary allocation of contention-based resources in advance, allowing user terminals to transmit data immediately without waiting for explicit scheduling grants. This preliminary resource assignment resolves the contradiction by enabling immediate data transmission while maintaining reliable resource management through pre-configured contention parameters.
Solution Approach 2:
User terminals autonomously select and transmit data using contention-based resources without requiring explicit scheduling requests and grants from the network. This self-service mechanism eliminates scheduling request delays and processing delays while maintaining reliable resource allocation through pre-configured contention parameters, thus resolving the time-loss contradiction.
2Reliability
If scheduled return link resources are used, then transmission reliability is improved, but scheduling request opportunity delays increase
Solution Approach 1:
The invention extracts the scheduling request and grant exchange mechanism from the data transmission process by implementing contention-based access. User terminals directly transmit data using pre-configured contention resources without going through the scheduling request opportunity cycle, thereby eliminating scheduling request delays while maintaining transmission reliability through proper resource management.
Solution Approach 2:
The network performs preliminary configuration of contention-based resources including resource blocks, time slots, and collision resolution parameters before data transmission begins. This preliminary setup allows user terminals to immediately access resources without scheduling request delays, resolving the contradiction between transmission reliability and scheduling delays.
3Ease of operation
If scheduled return link resources are used, then resource allocation control is improved, but processing delays increase
Solution Approach 1:
User terminals autonomously handle data transmission by independently selecting contention-based resources and resolving collisions according to pre-configured rules, eliminating the need for network processing of scheduling requests and grants. This self-service approach maintains resource allocation control through initial configuration while eliminating processing delays.
Solution Approach 2:
The invention extracts the network processing step from the data transmission path by implementing contention-based access where terminals autonomously manage their transmissions. This removes the processing delay component while maintaining resource allocation control through pre-configured contention parameters and network monitoring.
4Loss of time
If contention-based resources are used, then data transmission delay is reduced, but resource collision probability increases
Solution Approach 1:
The system dynamically adjusts contention-based resource parameters including resource block allocation, time slot duration, and collision resolution thresholds to optimize the balance between transmission speed and collision probability. By changing these parameters based on system load and conditions, the invention reduces transmission delays while maintaining acceptable collision rates through adaptive parameter optimization.
Solution Approach 2:
The network monitors contention-based transmissions and provides feedback regarding collision detection and resource utilization. This feedback mechanism allows dynamic adjustment of contention parameters and collision resolution strategies, reducing collision probability while maintaining the low-latency benefits of contention-based access.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Methods and apparatuses are disclosed for a user terminal (UT) to transmit data to a network controller via a satellite in a satellite system. The UT may begin transmitting, during a time period, a first portion of the data using contention-based resources of the satellite system prior to receiving a grant of scheduled return link resources of the satellite system. The UT may also transmit, on the contention-based resources, a buffer status report (BSR) during the time period. The UT may terminate data transmissions on the contention-based resources after an expiration of the time period or upon receiving the grant of scheduled return link resources. After receiving the grant, the UT may transmit a second portion of the data on the scheduled return link resources.