ARFCN Table for Wireless System Selection Optimization

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Solution Overview

Problem

In 3GPP wireless networks, wireless mobile devices face lengthy initial access times due to the need to scan a wide range of potential frequencies to determine the appropriate absolute radio frequency channel number (ARFCN) during initialization or re-selection, as they lack prior knowledge of the frequencies to use.

Innovation Solution

A method and system where an ARFCN table is stored in the mobile device or generated by a server, using location data such as MCC, MNC, and GPS coordinates to pre-identify the most likely ARFCN, allowing the device to initiate scanning on known frequencies rather than all possible ones, reducing the search time for initial access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the wireless mobile device performs an exhaustive frequency scan to determine the appropriate ARFCN during initialization, then the device can reliably access the network, but the initial access time becomes considerable and lengthy

Engineering Contradiction:
Improvenetwork access reliabilityVSAvoidinitial access time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-storing ARFCN information in the wireless mobile device before initialization occurs. The device maintains a database of ARFCN values associated with different locations, networks, or service providers, allowing it to retrieve the appropriate frequency without performing an exhaustive scan during startup. This pre-prepared information enables the device to jump directly to the correct frequency, significantly reducing initial access time while maintaining reliable network connection.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If the wireless mobile device scans a wide frequency range to ensure comprehensive network detection, then the device can find all available networks, but the system access time is delayed

Engineering Contradiction:
Improvenetwork detection coverageVSAvoidsystem access time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent stores ARFCN information in advance in the device memory, organized by location, network identifier, or service provider. When the device needs to access a network, it queries this pre-stored information using identifiers such as cell ID, location area code, or service provider code to directly retrieve the appropriate ARFCN values. This eliminates the need to scan the entire frequency spectrum, maintaining comprehensive network detection capability while dramatically reducing access time.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent segments the frequency scanning process by dividing the wide frequency range into specific ARFCN channels that are pre-identified and stored. Instead of scanning all possible frequencies continuously, the device segments the search to only those specific frequency channels that are relevant to its current location or service provider, as determined by the pre-stored ARFCN information. This segmentation maintains comprehensive detection of available networks while reducing the total scanning time.

Inventive Principle:
Principle #1Segmentation

3Reliability

If the wireless mobile device performs a full reset and re-sync to the network, then the device can re-establish proper network connection, but the re-initialization process takes considerable time

Engineering Contradiction:
Improvenetwork synchronizationVSAvoidre-initialization time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by maintaining ARFCN information in the device's memory even after reset events. When a full reset occurs, the device retrieves the pre-stored ARFCN information associated with its current location or service provider and uses it to quickly re-establish network connection without performing a complete frequency scan. This preserves network synchronization reliability while significantly reducing re-initialization time compared to traditional exhaustive scanning methods.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2421303B1Method for wireless system selection optimization
Publication Date: 2013.08.07 BLACKBERRY LTD
  • EP2421303B1 patent drawingFigure 1
  • EP2421303B1 patent drawingFigure 2
  • EP2421303B1 patent drawingFigure 3

AI summary

A method for improved system selection by wireless mobile devices in 3GPP networks is provided. Location data is retrieved by the wireless device to estimate an initial system on which the wireless mobile device will attempt initialization. Using the location data, an absolute radio frequency channel number (ARFCN) associated with the location data is determined from a ARFCN table stored in memory in the wireless mobile device. The wireless mobile device can then perform system selection using the determined ARFCN. A server generates and maintains the ARFCN table which is initially provided to the wireless mobile device at manufacturer, during provisioning or as an over-the-air update.