Ambiguous Small Cell Handover via Geolocation and Common Channel
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Solution Overview
Problem
Current communication systems face challenges in efficiently managing handover of user equipment from macro networks to small cell access points, particularly when the small cell access points are ambiguous, leading to inefficient use of network resources and potential handover failures due to the reuse of sub-carrier IDs across multiple small cells.
Innovation Solution
A method is introduced that involves determining potential target small cell access points using geolocation and sub-carrier information, configuring a common channel for handover, and managing landing channels across the system to optimize handover processes, including the use of databases to filter and identify suitable small cells within a specified range of the macro radio's coverage area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a handover request is sent identifying the serving large cell and the physical cell identity of one of the small cells, then the handover process can be initiated, but the request may not unambiguously identify an individual small cell among a plurality of small cells
Solution Approach 1:
The patent introduces a new dimension of identification by combining physical cell identity with geolocation data. Instead of relying solely on the physical cell identity which may be ambiguous, the system adds spatial coordinates as an additional identification dimension, allowing unique identification of small cells through their location in addition to their identity parameters.
Solution Approach 2:
The patent introduces a gateway or network controller as an intermediary that receives the ambiguous handover request, queries the database using the physical cell identity, retrieves the geolocation information, and then identifies the specific small cell based on location matching. This intermediary resolves the ambiguity by adding the geolocation lookup step.
2Productivity
If multiple small cell access points reuse the same sub-carrier ID, then network resources are efficiently utilized, but it becomes difficult to distinguish between individual small cells during handover
Solution Approach 1:
The patent resolves the sub-carrier ID reuse problem by adding geolocation as another dimension of identification. When multiple small cells share the same sub-carrier ID, the system differentiates them by their spatial coordinates stored in the database, allowing unique identification despite identical frequency resources.
Solution Approach 2:
The patent changes the identification parameters from relying solely on sub-carrier ID to using a combination of sub-carrier ID and geolocation coordinates. By modifying the identification approach to include spatial parameters, the system can distinguish between cells that share the same frequency resources.
3Reliability
If the system prepares handover for multiple potential target small cell access points, then handover success rate is improved, but network resource consumption increases
Solution Approach 1:
The patent performs preliminary actions by pre-storing geolocation information and sub-carrier ID mappings in a database during network setup. When a handover request arrives, the system quickly queries this pre-prepared database rather than performing complex real-time measurements, reducing the computational resources needed during the actual handover process while maintaining multiple target options.
Data Source
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AI summary
An example method is provided in one example embodiment and includes receiving a request to relocate a user equipment (UE) from a source macro radio to an ambiguous small cell access point (AP), wherein the request includes a target cell identity (ID) encoded with a source macro cell identifier for the source macro radio and a target sub-carrier identifier for the ambiguous small cell AP; determining potential target small cell APs for relocation of the first UE using the using the first target cell ID, wherein each of the potential target small cell APs are within a coverage area of the source macro radio and operate using the target sub-carrier identifier; and preparing, for each of the potential target small cell APs, a common channel to receive relocation of the first UE. The first UE can relocate to a particular target small cell access point using the common channel. The invention proposes a solution to the problem of PCI (Physical Cell Identity) or PSC (Primary Scrambling Code) confusion which arises due to the insufficient number of PCIs or PSCs for small cells for the pre-Release 9 UEs.