Bluetooth Long-Range Link Adaptation via Rate Indication Field

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Solution Overview

Problem

Existing link management protocols for Bluetooth low energy (BLE) long-range wireless networks are slow to adapt to varying signal-to-noise ratios (SNRs), leading to higher power consumption and difficulty in maintaining reliable communication over long distances due to slow rate adaptation and reliance on unreliable LMP message exchanges.

Innovation Solution

Incorporating a novel rate indication (RI) field in data packets to enable fast link adaptation, allowing the transmitting device to unilaterally adjust data rates based on link quality without relying on receiver feedback, and using different modulation and coding schemes to support variable data rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If existing LMP-based link management protocol is used for rate adaptation, then protocol compatibility is maintained, but adaptation speed is slow and power consumption increases

Engineering Contradiction:

Improverate adaptation speedVSAvoidpower consumption

Core Design Contradiction:

SpeedVSUse of energy by moving object

Solution Approach 1:

The patent incorporates rate indication information directly into the PHY header of downlink packets before transmission. This preliminary action allows the receiver to prepare for rate changes in advance without waiting for LMP feedback, enabling faster adaptation while reducing retransmission-related power consumption

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback mechanisms where the receiver indicates preferred rates or acknowledges received packets, allowing the transmitter to adjust rates dynamically. This feedback loop enables the system to adapt to channel conditions changes faster than traditional LMP-based approaches

Inventive Principle:

Principle #23Feedback

2Reliability

If LMP message exchange is relied upon for rate adaptation, then protocol stability is maintained, but reliability deteriorates in poor SNR conditions

Engineering Contradiction:

Improvelink qualityVSAvoidrate adaptation operation

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent segments the packet into header and payload portions, with the header containing rate indication information that is transmitted reliably even in poor SNR conditions. This segmentation ensures that rate control information can be exchanged independently of the data payload, maintaining reliability during rate adaptation

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent enables the receiver to unilaterally indicate preferred rates or acknowledge packets without requiring complex LMP message exchanges. This self-service approach allows each device to autonomously adjust rates based on local channel conditions, improving reliability in poor SNR environments

Inventive Principle:

Principle #25Self-service

3Adaptability or versatility

If single data rate is used for simplicity, then device complexity is reduced, but adaptability to varying SNR deteriorates

Engineering Contradiction:

ImproveSNR adaptation capabilityVSAvoidrate control complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic rate adjustment by incorporating rate indication fields in packet headers and using receiver feedback mechanisms. This dynamic approach allows the system to adapt data rates in real-time based on channel conditions while maintaining manageable complexity through standardized PHY layer modifications

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the data rate parameter dynamically by incorporating rate indication information in packet headers and using receiver feedback. This parameter change mechanism enables the system to adapt to varying SNR conditions through modifications to existing PHY layer parameters rather than requiring complex reconfiguration

Inventive Principle:

Principle #35Parameter changes

4Use of energy by moving object

If fast rate adaptation is implemented, then power consumption is reduced, but connection time increases due to negotiation overhead

Engineering Contradiction:

Improvepower consumptionVSAvoidconnection time

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The patent performs preliminary rate indication in the PHY header before data transmission begins. This preliminary action eliminates the need for lengthy LMP rate negotiation during connection establishment, reducing connection time while enabling fast rate adaptation during data transfer to save power

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS9813189B2Rate indication and link adaptation for variable data rates in long range wireless networks

Publication Date: 2017.11.07 MEDIATEK INC

AI summary

A method of fast link adaptation for Bluetooth long-range wireless networks is provided. A data packet comprises a preamble, a first packet portion including a rate indication field, and a second packet portion including a PDU. The first packet portion is encoded using a first modulation and coding scheme with a first rate while the second packet portion is encoded using a second modulation and coding scheme with a second rate indicated by the RI field. A transmitter thus can use different MCS options to support variable data rates by adapting to channel conditions, and then uses the novel RI field to indicate the data rate to a receiver dynamically. As a result, fast link adaptation can be achieved for different applications with different rate requirements, to provide higher data rate, reduce connection time, lower power consumption, and improve link quality.