Co-located Body Area Network RST Synchronization

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current MAC protocols, such as IEEE 802.15.4, are inadequate for body area networks (BANs) as they do not support mobility and coexistence, leading to collisions and inefficiencies in medium access, especially in scenarios where multiple BANs are co-located and devices move in and out of range.

Innovation Solution

A method is introduced to coordinate access to a wireless medium among multiple co-located BANs by detecting misaligned round start times (RST) between BANs, determining an initiator and target BAN, and realigning the RST of the initiator BAN with the target BAN's RST, using a two-tier architecture with master and slave devices and a distributed beaconing process to synchronize medium access and prevent collisions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple co-located BANs operate independently without coordination, then each BAN can function autonomously, but collisions occur between transmissions from different BANs

Engineering Contradiction:

Improveautonomous operationVSAvoidtransmission reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent merges the medium access coordination of multiple independent BANs by introducing inter-BAN beacon listening and RST synchronization. Master devices listen to beacons from alien BANs and adjust their own RST to align with detected BANs, creating a coordinated access pattern that prevents collisions while preserving autonomous operation of each BAN.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The beacon mechanism serves as an intermediary that enables coordination between independent BANs. By listening to and responding to beacons from other BANs, master devices can synchronize their RST without requiring direct communication or centralized control, thus maintaining autonomy while achieving collision-free operation.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Use of energy by moving object

If BAN devices use duty cycling to save energy, then energy efficiency improves, but idle listening and overhearing increase

Engineering Contradiction:

Improveenergy efficiencyVSAvoididle listening energy

Core Design Contradiction:

Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The patent applies preliminary action by having master devices listen to beacons from other BANs before initiating their own transmissions. This advance knowledge of other BANs' activity patterns allows devices to schedule their transmissions during idle periods, avoiding collisions and reducing the need for repeated idle listening and collision recovery attempts.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The beacon listening mechanism provides feedback about other BANs' transmission patterns. Master devices use this feedback to adjust their duty cycling schedules, aligning their active periods with detected idle periods in other BANs, thereby reducing idle listening energy while maintaining collision-free operation.

Inventive Principle:

Principle #23Feedback

3Adaptability or versatility

If IEEE 802.15.4 MAC protocol is used for BANs, then standard compliance is achieved, but mobility and coexistence support are inadequate

Engineering Contradiction:

Improvemobility supportVSAvoidprotocol complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces dynamic RST adjustment capability to the static IEEE 802.15.4 MAC protocol. Master devices can dynamically change their RST based on detected alien BANs, enabling mobility support and adaptive coexistence while maintaining the basic structure and compliance of the original protocol.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the RST parameter dynamically based on environmental conditions (detected BANs). This parameter change enables the protocol to adapt to mobility scenarios and multiple co-located BANs without requiring a complete protocol redesign, thus adding versatility while controlling complexity.

Inventive Principle:

Principle #35Parameter changes

4Reliability

If GTS reservations are made only within a single BAN, then internal QoS is guaranteed, but collisions occur with GTS transmissions from other BANs

Engineering Contradiction:

ImproveQoS guaranteeVSAvoidinter-BAN coordination

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent extends the GTS reservation mechanism from single-BAN to multi-BAN scope. By listening to beacons from alien BANs and synchronizing RST, master devices can identify and avoid time slots reserved by other BANs, making the GTS mechanism universal across multiple BANs while preserving internal QoS guarantees.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentEP2314092B1Techniques for supporting harmonized co-existence of multiple co-located body area networks

Publication Date: 2017.01.18 KONINKLIJKE PHILIPS NV

AI summary

A method (400) for coordinating access to a wireless medium among multiple co-located body area networks (BANs). The method comprises detecting, by a master device of a first BAN, at least one alien BAN using beacons received from at least one co-located BAN, wherein an alien BAN is a BAN having its round start time (RST) misaligned with a RST of the first BAN (S410); recording a RST offset between the first BAN and the at least one alien BAN (S420); based on the RST offset determining which of the first BAN and the at least one alien BAN is an initiator BAN and which is a target BAN (S430); and realigning the RST of the initiator BAN with the RST of the target BAN (S460).