NB-IoT Multicarrier Allocation Using PRB and NACK Feedback
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Solution Overview
Problem
Existing NB-IoT systems face challenges in efficient multicarrier allocation, leading to resource inefficiencies and communication delays due to limited bandwidth and high NACK percentages, which affect the throughput and utilization of radio resources.
Innovation Solution
A system and method for dynamic multicarrier allocation that selects the best ARFCN or PRB as a non-anchor carrier based on PRB utilization data and NACK percentage reports, optimizing resource allocation and minimizing frequency space requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a non-anchor carrier is allocated to NB-IoT enabled device for data transfer, then the data transfer capacity is improved, but the frequency space requirement increases by 180 kHz bandwidth
Solution Approach 1:
The patent implements dynamic allocation of non-anchor carriers where the carrier assignment is not fixed but changes based on real-time channel conditions, traffic demands, and device requirements. The network can dynamically switch devices between anchor and non-anchor carriers, and between different non-anchor carriers, to optimize resource utilization and minimize frequency space consumption while maintaining data transfer capacity.
Solution Approach 2:
The patent makes the anchor carrier multi-functional by allowing it to serve both as the primary control carrier (for RACH, paging, system information) and as a data carrier when needed. Additionally, non-anchor carriers can be dynamically assigned and reassigned to multiple devices based on demand, making the frequency resources more versatile and reducing the total frequency space required per device.
2Device complexity
If a single anchor carrier is used for all NB-IoT devices, then the system complexity is reduced, but communication delays occur due to limited bandwidth
Solution Approach 1:
The patent segments the NB-IoT carrier resources by introducing multiple non-anchor carriers that can be dynamically allocated to different devices or device groups. This segmentation divides the traffic load across multiple frequency resources, reducing contention and communication delays on the anchor carrier while maintaining relatively simple anchor carrier functionality for control purposes.
Solution Approach 2:
The patent adds the frequency dimension to resource allocation by introducing multiple non-anchor carriers at different frequency positions. Instead of only time-domain multiplexing on a single carrier, the system utilizes frequency diversity to parallelize data transfers, thereby reducing delays without significantly increasing system complexity.
3Ease of operation
If non-anchor carriers are allocated based on static rules, then the allocation process is simplified, but resource utilization efficiency decreases
Solution Approach 1:
The patent implements dynamic carrier allocation where the selection and assignment of non-anchor carriers is based on real-time channel quality indicators, device mobility status, traffic patterns, and network load conditions. This dynamic approach continuously adapts to changing conditions to maximize resource utilization efficiency while maintaining manageable allocation processes through automated decision-making algorithms.
Solution Approach 2:
The patent incorporates feedback mechanisms where the network monitors the performance of allocated non-anchor carriers (including NACK percentages, throughput, and channel conditions) and uses this feedback to make informed allocation decisions. This feedback-driven approach optimizes resource utilization by allocating carriers that demonstrate better performance characteristics while keeping the allocation process systematic and manageable.
4Quantity of substance
If carriers with high NACK percentages are used for data transfer, then the available frequency resources are maximized, but communication reliability decreases
Solution Approach 1:
The patent converts the harmful effect of high NACK percentages into a beneficial selection criterion. By identifying carriers with high NACK percentages and excluding them from allocation to devices experiencing similar issues, the system transforms what would be a resource waste into a smart avoidance strategy. This approach ensures that frequency resources are allocated to device-carrier combinations with better reliability characteristics.
Solution Approach 2:
The patent uses NACK percentage feedback from uplink transmissions as a key parameter in the carrier allocation decision-making process. The network monitors NACK rates on different carriers and for different devices, and uses this feedback to dynamically adjust allocations, avoiding assignments that would result in poor reliability while still maximizing the utilization of available frequency resources.
Data Source
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AI summary
Present disclosure generally relates to wireless communication and particularly relates to system and method for dynamic multicarrier allocation to NB-IoT devices. Method includes receiving from PMS, PRB utilization data for a time slot or data packets, and comparing PRB utilization duration in received PRB utilization data with pre-defined threshold PRB utilization duration. Requesting via NB-IoT eNB, cumulative NACK percentage report corresponding to ARFCN/PRB, if PRB utilization duration is less than a pre-defined threshold. Method includes selecting, ARFCN/PRB for a time slot, based on PRB utilization data and cumulative NACK percentage report and pre-defined value. Method includes establishing connection between NB-IoT enabled devices and NB-IoT eNB, upon transmitting via LTE eNB, information associated with selected ARFCN/PRB for time slot, to NB-IoT eNB. Method includes notifying LTE eNB, representative of utilization of ARFCN/PRB as non-anchor carrier. Method includes allocating ARFCN/PRB as non-anchor carrier to schedule NB-IoT enabled devices for data transfer in selected time slot.