Dynamic PLMN Selection for Link Budget Limited Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Link budget limited wireless devices face challenges in maintaining reliable packet-switched communication services due to limited reception and transmission capabilities, which are exacerbated by their design constraints and environmental factors, leading to reduced coverage and connectivity issues compared to standard phones.
Innovation Solution
The implementation of a method in user equipment (UE) devices to dynamically select the most preferred public land mobile network (PLMN) based on signal strength and geographic location, using a PLMN eSIM priority lookup table sorted by priority order and updated at runtime, allowing the device to switch to a better carrier when the current one's signal strength falls below a threshold, leveraging crowd-sourced data for improved coverage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If link budget limited devices use fixed carrier selection, then device complexity is reduced, but coverage and connectivity are deteriorated
Solution Approach 1:
The patent implements dynamic carrier selection where the device automatically switches between home and roaming carriers based on real-time signal strength measurements and predefined thresholds. This dynamic adaptation allows link budget limited devices to maintain connectivity by selecting the optimal carrier in changing environmental conditions, resolving the contradiction between fixed simplicity and dynamic performance.
Solution Approach 2:
The system continuously monitors signal strength from both home and roaming carriers and uses this feedback to make intelligent carrier selection decisions. When home carrier signal drops below a threshold, the device switches to roaming carrier; when home carrier signal improves, it switches back. This feedback mechanism enables automated optimization without increasing perceived device complexity.
2Reliability
If link budget limited devices frequently switch carriers to maintain signal, then connectivity is improved, but battery power consumption increases
Solution Approach 1:
The patent implements hysteresis in the carrier selection logic by setting different thresholds for switching to roaming carrier versus switching back to home carrier. This prevents oscillation around the threshold boundary and reduces unnecessary switching events, thereby conserving battery power while maintaining connectivity reliability.
Solution Approach 2:
The system pre-configures threshold values and carrier priority rules to anticipate signal degradation scenarios. By having predetermined switching criteria in place, the device avoids making suboptimal switching decisions that would waste energy, and only switches when genuinely necessary for maintaining connectivity.
3Volume of moving object
If link budget limited devices use simplified antenna design, then device size is reduced, but reception capability is deteriorated
Solution Approach 1:
The patent enables a single antenna to effectively serve multiple carriers by implementing carrier selection logic that adapts to available signal conditions. The same physical antenna infrastructure is used for both home and roaming carriers, maximizing the utility of the limited hardware resources in link budget limited devices.
Solution Approach 2:
The system changes operational parameters (carrier frequency, signal thresholds, selection criteria) rather than physical hardware parameters to compensate for limited antenna capabilities. By dynamically adjusting which carrier is used based on signal conditions, the device optimizes reception performance despite having a simplified, space-constrained antenna design.
Data Source
AI summary
Techniques for a link budget limited UE to improve communications performance with cellular networks are disclosed. The UE may be associated with subscriptions to multiple carriers and may connect to a cell of a first carrier. The UE may detect that received signal strength from the cell is below a threshold and search for a new cell that may be of a different carrier. The UE may store a PLMN eSIM priority look up table and the search may be based on the look up table. Additionally, the UE may track received signal strength and geographic location in a first data structure that the UE may send to a server. The UE may receive a second data structure from the server that includes received signal strength at geographic locations compiled from a plurality of UEs, including the UE. The UE may also use the second data structure in searches for a new cell.