Semi-Persistent Scheduling for MTC Control Channel Overhead
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Solution Overview
Problem
Wireless communication systems face challenges in reducing control channel overhead for low-cost, low-complexity machine-type communication (MTC) devices, particularly under poor radio link conditions, where semi-persistent scheduling (SPS) and coverage enhancement techniques are needed to improve transmission reliability.
Innovation Solution
Implementing semi-persistent scheduling (SPS) with predefined transmission periods and coverage enhancement levels to reduce control channel overhead, allowing MTC devices to prioritize and manage resources effectively, including bundling transmissions and dynamic resource assignment management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If dynamic scheduling is used for MTC devices, then resource allocation flexibility is improved, but control channel overhead increases significantly
Solution Approach 1:
The patent applies periodic action by implementing semi-persistent scheduling where resources are allocated periodically to MTC devices rather than dynamically scheduled each time. The network configures SPS parameters including periodicity, and devices automatically receive resources at regular intervals, eliminating the need for continuous control channel signaling while maintaining efficient resource utilization for periodic MTC traffic patterns.
2Quantity of substance
If SPS is used to reduce control channel overhead, then overhead is reduced, but resource allocation flexibility decreases
Solution Approach 1:
The patent applies dynamics by allowing transition between SPS and dynamic scheduling modes. The network can activate or deactivate SPS based on traffic conditions, and devices can switch between SPS-assigned resources and dynamically scheduled resources. This dynamic adaptability maintains resource allocation flexibility while reducing control channel overhead during periods when SPS is active.
Solution Approach 2:
The patent applies universality by designing a hybrid scheduling framework that can handle both SPS and dynamic scheduling within the same system. The resource allocation mechanism is universal enough to support periodic SPS assignments for traffic with predictable patterns while also accommodating dynamic scheduling for traffic requiring flexible resource allocation, making the system adaptable to various MTC application requirements.
3Reliability
If transmissions are bundled for coverage enhancement, then transmission reliability is improved, but resource consumption increases
Solution Approach 1:
The patent applies partial action by implementing selective transmission bundling where repetitions are applied only when coverage enhancement is needed. The network can configure different CE levels, and devices can adjust the number of repetitions based on channel conditions and traffic requirements. This partial application of bundling maintains transmission reliability for devices with poor radio conditions while avoiding excessive resource consumption for devices with good channel quality.
Data Source
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AI summary
Methods, systems, and devices for wireless communication are described. Semi-persistent scheduling (SPS) may be used for communication with various wireless communication devices, including machine-type communication (MTC) devices, to reduce overhead on control channels. Data transmissions scheduling using SPS techniques may be repeated and bundled together to effect coverage enhancement (CE) for devices with poor radio quality conditions. SPS communication may be used in both uplink and downlink transmissions. An SPS configuration may include a predefined number of scheduled transmission periods and a CE level, which may be established in either an SPS configuration message or as part of the SPS activation message from a base station. A device may identify the CE level of the transmissions and, in some cases, may determine the periodicity of the SPS based on the CE level. Bundled transmissions assigned with SPS may be prioritized with respect to one another or dynamically assigned resources.