Using Multi Bluetooth iBeacon Trilateration For Increased Accuracy

There’s a new paper from the journal Telkomnika Telecommunication, Computing, Electronics and Control on Smartphone indoor positioning based on enhanced BLE beacon multi-lateration (pdf). The paper by Ngoc-Son Duong of Vietnam National University describes a relatively simple method to improve location accuracy.

The paper starts by describing trilateration and the author voices the opinion that another method, fingerprinting, requires a lot of effort and isn’t feasible for practical implementation.

The new method makes use of the fact that accuracy is usually good when the received signal strength (RSSI) is -70 dBm or better. The use of more beacons and basing calculations on ‘reliable circles’ of higher signal strength, when available, provides for more accuracy.

The data is also filtered using a Kalman filter to reduce signal noise by about 37%.

Read about Determining Location Using Bluetooth Beacons

Real Time Location Systems (RTLS) in Healthcare

Due to the pandemic, hospitals and care facilities have been experiencing greater patient numbers leading to pressures to accelerate digital transformation to increase efficiency. At BeaconZone, these are the main reasons customers have been using locating systems:

  • To save time searching for equipment, particularly highly mobile equipment such as wheelchairs
  • To monitor the location and temperature of medicines
  • To monitor the location of hospital porters
  • To track the location of vulnerable patients
  • To audit the visiting of care givers to patients

However, there are many more areas suitable for increasing efficiency and safety:

  • Tracking expensive assets such as beds and medical devices
  • Tracking rental/borrowed equipment to ensure they are returned on time to avoid unintended costs
  • Staff distress SOS for increased safety
  • Hygiene management, for example, on hand washing stations
  • Inventory counts and stock checks
  • Analysis of workflows to detect choke points and streamline processes
  • Production of key metrics such as time being spent with patients, patient throughput and wait times

Time saved improving the above activities leads to more time being spent with patients and hence potentially saved lives.

Here are some considerations if you are comparing solutions:

  • Tag costs – Prefer commodity rather than proprietary hardware to reduce costs and allow 2nd sourcing to reduce future risk
  • Real time – Prefer systems that detect continuously over those that rely on error-prone manual scanning
  • Scalable – Prefer software systems that will scale financially, particularly in large hospitals
  • Ongoing costs – Prefer systems that have known future system costs – ideally with a one-off licence rather than varying subscription.

One final tip. It’s our experience that healthcare providers under-estimate the human element in attempting to implement new systems. There are often internal problems as to who will be responsible for a) purchasing, b) installing and c) running new systems. Work these out and agree up-front before embarking on these transformative changes so as to prevent your project becoming blocked.

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Bluetooth Low Energy Emulator

Researchers from Japan have created a Bluetooth Low Energy Emulator for testing devices. Their paper, BluMoon: Bluetooth Low Energy Emulator for Software Testing BLE emulator called BluMoon for testing software systems using BLE (pdf), explains how it can be difficult to test how receiving Bluetooth devices’ behave when encountering other Bluetooth devices with varying signal level and interference.

The signal level and interference vary change depending on the position of the sender and receiver. They also vary depending on the surrounding environment. The signal level (RSS) is affected by reflection, shielding, and diffraction by surrounding objects, walls and the ground. Instead, testing requires known signal level and interference values.

The paper describes a software-implemented BLE controller, BluMoon, that calculates the received signal strength for each frame and imitates radio interference. The emulator replaces the controller with the HCI as the boundary.

BluMoon performs BLE communication emulation frame by frame and is implemented on Linux using the BlueZ Bluetooth stack.

Adding an IoT Protocol to Beacons

There’s new research by Department Computer Science, Universidad Técnica de Machala, Ecuador on Design and Practical Evaluation of a Family of Lightweight Protocols for Heterogeneous Sensing through BLE Beacons in IoT Telemetry Applications.

The researchers explain how standard beacon advertising works and documents the existing iBeacon and Eddystone protocols.

New protocols, LP4S-6 (for resource-constraint beacons), LP4S-X (for more powerful beacons) and LP4S-J (for beacons able to run complex firmware) are proposed that can be used to allow IoT telemetry systems to discover new nodes and to describe and auto-register the sensors and actuators connected to a beacon.

The paper describes the resultant JSON, shows how a new protocol can be added to an Eddystone beacon and proves how the new latency and power consumption remain low.

Note that updating the firmware of a beacon is non-trivial because it requires the implementation of what’s already on the beacon without access to the original source code.

Real Time Location Systems (RTLS) for The Fourth Industrial Revolution

The Fourth Industrial Revolution, also known as 4IR and Industry 4.0, improves manufacturing through the use of technology. The end-aims are to significantly improve productivity, reduce production delays and, for example, avoid penalties or future lost orders due to delayed work.

A key part of The Fourth Industrial Revolution is asset tracking that provides faster and more accurate stock control, item picking, job tracking, capacity measurement, demand analysis and product protection through sensing and automatic auditing.

It’s important that asset tracking is continuous because merely scanning things in/out using barcodes is open to human error and location is otherwise only as good as the last scan. Historical data is also important because it identifies blockages allowing processes to be refined.

When evaluating asset tracking systems consider:

  • Scalability and Performance – How many things do you need to track today and into the future?
  • Flexibility – Many of our customers initially buy an RTLS for one urgent purpose but later end up use the system system for additional needs.
  • Security – Where is your data stored and where does it go?

Look for a stand-alone solution rather than SAAS for greater performance, flexibility and longevity. While SAAS based systems can be a quick way into RTLS, they soon become limiting because you are sharing a platform with other customers. SAAS platforms usually don’t scale well technically and financially and don’t have efficient, direct access to the data for efficient ad-hoc reporting. They also pose potential security and reliability risks as you don’t own your data. The ultimate limitation comes when the SAAS provider, usually a startup, eventually increases costs, get’s bought out by its largest customer or goes out of business.

BeaconRTLS


Beacons in Industry and the 4th Industrial Revolution (4IR)

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Using Beacons in Clinical Trials

There’s recent research by Roche Pharma Research and Early Development (pRED), Switzerland on a Beacon-Based Remote Measurement of Social Behaviour in ASD Clinical Trials: A Technical Feasibility Assessment.

Beacons were used to determine the location of participants in an observational Autism Spectrum Disorder (ASD) clinical trial designed to assess social behaviour. Beacons were placed by the participants or caregivers in separate rooms in the household and a smartwatch used to detect the beacons as the participant moved from room to room. A smartphone app was used to map each beacon with each room.

A key aspect of the study is that it was conducted with no participant training and without the supervision of a technical person.

The study also provides a comparison with prior work and a comparison of locating technologies:

The researchers provide some good practice guidelines for using beacons for indoor locating:

  • Set the beacons to have the same transmission power to allow the signals to be comparable
  • Beacons should be placed in an open area in each room that is close to the activity centre of the room to minimize interference
  • Beacons should ideally have line of sight and face toward the participant and not considerably higher than the receiving smartwatch

The study achieved an accuracy of 97.2% proving that beacons have the potential to provide deep insights into in-home behaviour. This provides more objective data than would be the case with commonly used questionnaire-based studies.

PubNub Android Tutorials

We recently came across a great resource on PubNub that shows how to use Android to detect beacons and also transmit as a beacon.

The tutorial is in three parts that 1) Describes beacon advertising and how to scan for beacons 2) How to filter detected beacons 3) Setting up Android as an emitter.

There’s also a related PubNub article by the same author on how to Create a Tessel Beacon with a BLE Module.