Frequency Channel Grouping for Fast Wireless Sensor Network Synchronization

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Solution Overview

Problem

Frequency hopping wireless systems face challenges in achieving fast synchronization while minimizing transmission time on each channel, as existing methods often result in high synchronization latency and inefficient use of frequency channels, violating regulatory limits on channel usage.

Innovation Solution

The method involves dividing frequency channels into groups and transmitting synchronization information in recurring sequences, allowing nodes to sample channels efficiently, reducing transmission time and latency by alternating transmissions across groups of channels, thereby optimizing channel usage and adhering to regulatory constraints.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If synchronization information is transmitted on every frequency channel to ensure fast synchronization, then synchronization latency is reduced, but transmission time on each channel increases violating regulatory limits

Engineering Contradiction:

Improvesynchronization latencyVSAvoidtransmission time on channel

Core Design Contradiction:

Loss of timeVSUse of energy by moving object

Solution Approach 1:

The frequency channels are divided into multiple groups, and synchronization information is transmitted on only one channel per group rather than every channel. This segmentation allows the system to reduce transmission time on individual channels while still providing comprehensive synchronization coverage across all frequency groups.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of transmitting synchronization information on all frequency channels (excessive action), the system transmits on a subset of channels - specifically one channel per group (partial action). This partial transmission approach is sufficient for synchronization purposes while reducing overall transmission time and energy consumption.

Inventive Principle:

Principle #16Partial or excessive action

2Productivity

If synchronization is performed quickly to meet application requirements, then network operational time increases, but channel usage limits are violated

Engineering Contradiction:

Improvenetwork operational timeVSAvoidchannel usage time

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

By segmenting frequency channels into groups and selecting one representative channel per group for synchronization transmissions, the system achieves fast synchronization without excessive channel usage. This allows more time to be allocated to network operations while staying within regulatory channel occupancy limits.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system changes the parameter of transmission frequency by transmitting synchronization information on a reduced set of channels (one per group) rather than all channels. This parameter change reduces the total transmission time while maintaining synchronization effectiveness, thereby increasing time available for network operations.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If all frequency channels are used for synchronization transmissions, then synchronization reliability is improved, but time for other network operations decreases

Engineering Contradiction:

Improvesynchronization reliabilityVSAvoidtime for network operations

Core Design Contradiction:

ReliabilityVSDuration of action of moving object

Solution Approach 1:

The frequency spectrum is segmented into multiple groups, and synchronization is achieved by transmitting on one channel per group. This segmented approach maintains synchronization reliability across the entire frequency range while using fewer total channels for synchronization, leaving more time available for network operations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The selected synchronization channels serve multiple purposes: they provide synchronization information and can also be used for other network communications. This multi-functionality ensures synchronization reliability is maintained while maximizing the utilization of available time for network operations.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS8213482B2Method for fast synchronization and frequency hop sequence detection in wireless sensor networks

Publication Date: 2012.07.03 ROBERT BOSCH GMBH

AI summary

A method of synchronizing wireless devices includes establishing a recurring sequence of frequency channels at which the wireless devices are to communicate. The frequency channels are divided into a plurality of groups. Synchronization information is transmitted at a respective first frequency channel in each of the groups of frequency channels during a first sampling time period. One of the groups of frequency channels is selected. A wireless device is used to sample each of the frequency channels in the selected group during the first sampling time period. Non-synchronization information is transmitted after the first sampling time period. Synchronization information is transmitted at a next respective frequency channel in each of the groups of frequency channels during a next sampling time period. The next sampling time period occurs after the transmitting of the non-synchronization information.