Air Interface Coordination for Side-Link Coexistence
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Different air interface communication protocols, such as 4G LTE and 5G NR, used in side-link communications often result in inefficiencies due to the need for separate frequency channels and potential interference from incompatible subcarrier spacings, making coexistence and efficient resource allocation challenging.
Innovation Solution
A method and system that allocate a system resource pool among multiple air interfaces using non-overlapping time-windows, allowing 4G LTE and 5G NR to share the same frequency channel by subdividing it based on time, with fixed subcarrier spacing for 4G LTE and variable spacing for 5G NR, enabling simultaneous side-link communications without interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate frequency channels are allocated to each air interface protocol (4G LTE and 5G NR), then interference between incompatible subcarrier spacings is avoided, but frequency spectrum efficiency deteriorates due to channel fragmentation
Solution Approach 1:
The frequency channel is segmented into separate time-windows, with each time-window dedicated to a specific air interface protocol (4G LTE or 5G NR). This temporal segmentation allows different protocols to share the same frequency resources without interfering with each other, as they transmit at different times rather than simultaneously occupying separate frequency channels.
Solution Approach 2:
The solution transitions from frequency-domain separation to time-domain separation. Instead of allocating different frequency channels to different air interface protocols, the system uses time-division multiplexing where 4G LTE and 5G NR transmissions are separated in the time dimension, allowing efficient coexistence on the same frequency channel.
2Quantity of substance
If time-division multiplexing is used to share frequency channels among multiple air interfaces, then frequency spectrum efficiency is improved, but system complexity increases due to coordination requirements
Solution Approach 1:
An air interface coordination management server system acts as an intermediary to manage and coordinate resource pool allocations among multiple air interface protocols. This centralized coordinator receives resource pool allocation messages and distributes appropriate time-window assignments to different air interface systems, simplifying the coordination complexity by centralizing control rather than requiring distributed negotiation between protocols.
Solution Approach 2:
The system performs preliminary allocation of resource pools and time-windows before actual communication occurs. The air interface coordination management server system pre-configures and distributes time-window assignments to different air interface protocols, allowing UEs to be notified in advance of their allocated resources, thereby reducing real-time coordination complexity during actual transmissions.
3Reliability
If 4G LTE and 5G NR use different subcarrier spacings, then each protocol maintains its optimal performance, but coexistence on the same channel becomes difficult due to potential interference
Solution Approach 1:
The system implements periodic time-windows assigned to each air interface protocol, where 4G LTE and 5G NR transmissions occur in alternating periodic intervals on the same frequency channel. This periodic time-division approach allows each protocol to maintain its optimal subcarrier spacing configuration while enabling coexistence, as the periodic separation in time prevents interference between the different spacing configurations.
Data Source
AI summary
Various arrangements for using multiple air interfaces on a frequency channel for side-link communications are presented. Side-link communications may be performed using the first air interface during only a first time-window of a system resource pool while side-link communications may be performed using a second air interface during a second time-window of the system resource pool.