Vertical Handoff Channel Search Using Pre-Collected WLAN Data

Solution Overview

Problem

Vertical handoffs in wireless networks often result in time delays and excessive energy consumption due to successive channel searches, particularly when transitioning to a WLAN, which can be inefficient and wasteful.

Innovation Solution

A channel search method and system that prioritizes and determines a channel search order by collecting channel information from a first terminal already connected to a WLAN node, allowing a second terminal entering the coverage area to quickly perform a vertical handoff and reduce power consumption by giving priority to the identified channel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a successive channel search from first channel to eleventh channel is performed to locate a communicable channel, then the terminal can find a channel for vertical handoff, but a time delay is caused and energy is wasted

Engineering Contradiction:

Improvechannel connection reliabilityVSAvoidvertical handoff time delay

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having the terminal collect and store channel information from neighboring WLAN nodes before actually needing to perform a vertical handoff. When entering a coverage area, the terminal retrieves pre-collected channel information to determine the search order, rather than performing a complete successive search from the first channel. This preparatory collection of channel data enables faster handoff execution.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by utilizing channel information collected from existing connections with WLAN nodes. The terminal uses feedback from the first terminal's channel connection status to optimize the second terminal's channel search strategy. This feedback mechanism allows the system to adapt the search order based on actual channel conditions observed by neighboring terminals.

Inventive Principle:

Principle #23Feedback

2Reliability

If a successive channel search from first channel to eleventh channel is performed to locate a communicable channel, then the terminal can find a channel for vertical handoff, but energy consumption increases

Engineering Contradiction:

Improvechannel connection reliabilityVSAvoidterminal energy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies preliminary action by having the terminal collect and store channel information from neighboring WLAN nodes before actually needing to perform a vertical handoff. When entering a coverage area, the terminal retrieves pre-collected channel information to determine the search order, rather than performing a complete successive search from the first channel. This preparatory collection of channel data enables faster handoff execution.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by utilizing channel information collected from existing connections with WLAN nodes. The terminal uses feedback from the first terminal's channel connection status to optimize the second terminal's channel search strategy. This feedback mechanism allows the system to adapt the search order based on actual channel conditions observed by neighboring terminals.

Inventive Principle:

Principle #23Feedback

3Productivity

If channel information is collected from a first terminal and used to determine search order for a second terminal, then vertical handoff speed is improved, but system complexity increases

Engineering Contradiction:

Improvevertical handoff speedVSAvoidchannel search system complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary mechanism where channel information is collected and stored in a structured format that can be easily retrieved and processed. The channel information collection and storage acts as an intermediary layer between the complex wireless environment and the simplified search decision-making process. This intermediary structure enables fast lookup and determination of search order without requiring complex real-time analysis.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS8111675B2Channel search method and system for vertical handoff in wireless network environment

Publication Date: 2012.02.07 SAMSUNG ELECTRONICS CO LTD

AI summary

A channel search method for a vertical handoff in a wireless network environment is provided, the channel search method including: collecting channel information from a first terminal which is provided with a wireless local area network (WLAN) service via a channel connection with a WLAN node; and determining a channel search order for a channel connection between a second terminal and the WLAN node by using the collected channel information. A channel search system for a vertical handoff in a wireless network environment is also provided, the channel search system including: a channel information collection unit for collecting channel information from a first terminal which is provided with a WLAN service via a channel connection with a WLAN node and a search order determination unit for determining a channel search order for a channel connection between a second terminal and the WLAN node by using the collected channel information.