NB-IoT Guard-Band Deployment Across Narrow LTE Carriers
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Solution Overview
Problem
Deploying an NB-IoT carrier in the guard-band of an LTE carrier with narrow bandwidths, such as 3 MHz or 5 MHz, is challenging due to limited PRB positions and resource conflicts with LTE carriers, making it difficult to meet 3GPP specifications and radio transmission requirements.
Innovation Solution
A method and RAN node that allows an NB-IoT carrier to be partially overlapped with the guard-band of an LTE carrier, adjusting the carrier's position to align with the 100 kHz raster and using inband-DifferentPCI mode to avoid resource conflicts, while maintaining orthogonality and compatibility with legacy UEs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If an NB-IoT carrier is deployed in the guard-band of an LTE carrier with narrow bandwidth (3 MHz or 5 MHz), then spectrum utilization is improved, but resource conflicts with LTE carriers occur and PRB positions are limited
Solution Approach 1:
The NB-IoT carrier is segmented into two parts: a first part located in the guard-band of the LTE carrier and a second part located in the LTE transmission bandwidth. This segmentation allows the NB-IoT carrier to utilize previously unavailable guard-band spectrum while avoiding direct resource conflicts with LTE carriers by distributing the carrier across different frequency regions with distinct resource allocation.
Solution Approach 2:
The patent introduces a new dimension of carrier deployment by allowing the NB-IoT carrier to span multiple frequency regions (guard-band and transmission bandwidth) simultaneously. This multi-dimensional frequency allocation enables flexible placement that avoids one-dimensional conflicts while maximizing spectrum utilization.
2Adaptability or versatility
If the NB-IoT carrier is positioned to align with the 100 kHz raster, then compatibility with legacy UEs is improved, but available PRB positions are limited
Solution Approach 1:
The patent implements dynamic positioning of the NB-IoT carrier by allowing the first part to be located at different positions within the guard-band and the second part at different positions within the LTE transmission bandwidth. This dynamic placement capability enables alignment with the 100 kHz raster for legacy UE compatibility while providing flexibility to select optimal PRB positions that avoid resource conflicts.
3Area of moving object
If inband-DifferentPCI mode is used to avoid resource conflicts, then spectrum utilization is improved, but configuration complexity increases
Solution Approach 1:
The patent utilizes parameter changes by configuring the NB-IoT carrier with specific physical cell identity (PCI) offsets relative to the LTE carrier. By adjusting the PCI parameter according to the carrier's position in the guard-band or transmission bandwidth, the system avoids resource conflicts while maintaining spectrum utilization efficiency.
Data Source
AI summary
The present disclosure is related to a RAN node and a method for network deployment based on partially overlapped carriers. A method at a RAN node for serving a first cell with a first carrier that is partially overlapped with a second carrier of a second cell comprises: broadcasting or transmitting, to one or more UEs, a first part of data in a first part of the first carrier that is overlapped with the second carrier and a second part of the data in a second part of the first carrier that is not overlapped with the second carrier.