Licensed-Assisted Sidelink Access for Stable FBE Carrier Offloading
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Solution Overview
Problem
Scheduling access to unlicensed spectrum for sidelink communications is not as efficient as scheduling access to licensed spectrum, leading to bandwidth limitations in vertical domains like Intelligent Transportation Systems, and existing frame-based equipment (FBE) access schemes are not suitable for synchronous channel access in New Radio Sidelink (NR SL) due to instability and competition issues.
Innovation Solution
A heterogeneous carrier aggregation design is implemented, offloading sidelink traffic from a licensed band primary carrier to an unlicensed band secondary carrier, using timing from the licensed band to coordinate FBE-based access, thereby reducing burden on the primary carrier and stabilizing channel access.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If sidelink traffic is transmitted in unlicensed spectrum, then bandwidth capacity increases, but channel access efficiency deteriorates
Solution Approach 1:
The patent introduces a licensed band as an intermediary control channel that mediates between devices and unlicensed spectrum resources. The licensed band carries sidelink control information (SCI) that coordinates access to unlicensed spectrum, allowing devices to efficiently share unlicensed resources without direct competition, thus maintaining high channel access efficiency while enabling large data bandwidth in unlicensed spectrum.
2Ease of operation
If FBE access scheme is used in unlicensed band, then channel access is simplified, but access stability deteriorates
Solution Approach 1:
The patent implements a feedback mechanism where devices transmit sidelink control information in the licensed band indicating their intent to access unlicensed spectrum resources. Receiving devices provide feedback through the licensed band about resource availability and access decisions. This feedback loop allows devices to adjust their FBE access timing and resources dynamically, maintaining simplicity while significantly improving access stability and reducing conflicts.
3Productivity
If all sidelink communication uses licensed spectrum, then access control is efficient, but spectrum burden increases
Solution Approach 1:
The patent segments sidelink communication into two distinct parts: control plane functions (resource allocation, coordination, signaling) are handled in the licensed band where efficient access control exists, while user plane data traffic is offloaded to unlicensed spectrum. This segmentation allows the system to leverage the access control efficiency of licensed spectrum for critical functions while using the abundant bandwidth of unlicensed spectrum for data transmission, thereby reducing the overall burden on licensed spectrum.
Data Source
AI summary
Aspects of the disclosure relate to, at a wireless communication device, occupying a slot in a first subchannel, wherein the first subchannel comprises a sidelink subchannel in a licensed band, transmitting sidelink control in the first subchannel during the slot, except during a symbol gap indicated to include at least a last symbol of a plurality of symbols supported by the slot, seeking access to a secondary carrier in an unlicensed band, and transmitting sidelink traffic in the secondary carrier upon receiving the access to the secondary carrier. Other aspects, embodiments, and features are also claimed and described.