Mobile Station Home PLMN Search Limiting via Neighbor Database
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Solution Overview
Problem
Wireless communication systems face inefficiencies in power consumption when mobile stations roam and search for their home PLMN, especially when far from the serving network, leading to unnecessary power waste as they exhaustively scan for frequencies and PLMN IDs.
Innovation Solution
Implementing a neighbor database stored on the mobile station to determine if the serving network is a neighbor of the home PLMN, allowing the station to skip searches when not in vicinity, thus conserving power by only searching when proximity is likely.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the mobile station performs periodic exhaustive searches for home PLMN while roaming, then the reliability of home network registration is improved, but the power consumption increases significantly
Solution Approach 1:
The network performs preliminary action by transmitting the neighbor PLMN list to the mobile station in advance through broadcast messages, registration messages, or LA/RA updates. This allows the mobile station to have prior knowledge of neighboring PLMNs before attempting home PLMN searches, enabling it to skip futile searches in non-neighbor networks and conserve power while maintaining registration reliability.
2Reliability
If the mobile station searches for home PLMN at regular fixed intervals, then the reliability of detecting home network availability is improved, but the power consumption increases due to frequent searches
Solution Approach 1:
Instead of performing exhaustive searches at all regular intervals, the mobile station applies partial action by skipping searches in PLMNs that are not in the neighbor list. The station only performs searches in neighbor PLMNs or when specifically triggered, reducing the number of search operations while maintaining adequate detection reliability through targeted searches.
3Measurement precision
If the mobile station performs exhaustive frequency and PLMN ID scanning, then the measurement precision of network identification is improved, but the time consumption and power usage increase
Solution Approach 1:
The solution extracts only the necessary PLMN identifiers from the exhaustive list by providing the mobile station with a neighbor PLMN list containing only relevant PLMN IDs. This allows the mobile station to focus measurements on a subset of likely candidate networks rather than scanning all possible frequencies and PLMN IDs, reducing search time while maintaining identification accuracy for relevant networks.
Data Source
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AI summary
Apparatus and methods are disclosed for reducing or eliminating searches by a UE for its home PLMN when the mobile station is roaming in a network not in the vicinity of the home PLMN. That is, the UE may be provisioned with information about its home PLMN. For example, some embodiments can comprise a neighbor database indicating neighbor relationships between PLMNs and the home PLMN. This can enable a UE to determine whether the home PLMN is likely to be nearby when it is visiting a different PLMN. Forgoing a PLMN home search reduces processing and can aid in conserving power resources. Other aspects, embodiments, and features are also claimed and described.