RTLS for Dummies by Ajay Malik [Book Review]

RTLS for Dummies: The Review

RTLS for Dummies by Ajay Malik [Book Review]

I have recommended this book many times to partners, solution architects, product marketers, managers and all those interested in Real Time Asset Tracking. Here, I outline my commentary and synopsis notes on the book RTLS for Dummies. At Kontakt.io we occasionally add our own view on things, especially on how Bluetooth Low Energy is changing the RTLS landscape since this book first appeared (find our white paper on BLE RTLS here).

Implementing a Real Time Location System (RTLS) is a complex endeavor. One of the recurring themes in our work is that once an organization considers an RTLS for a particular problem soon other stakeholders add their desires.

For example, a system may be initially designed to understand the utilization of intra-logistics to improve load balancing between production units and shifts. However, as the technology selection process starts, the operational risk team might desire to adjust the system to record the number of collisions of forklifts to reduce health and property damage risks.

Accommodating different use cases is often, but not always, possible. Use cases have particular requirements which touch on the accuracy, speed of location information, size and kind of asset and people tags, cost of infrastructure and complexity of maintenance. Understanding the trade-offs and the underlying technologies that inform them is essential for a successful implementation of a Real Time Location System – especially when you are looking to accommodate more than one use-case.

There are few more accessible and comprehensive resources than RTLS for Dummies by Ajay Malik to guide the decision making process. The former Director and VP of Engineering at Motorola, Cisco, and HP, as well as an employee of Google when he wrote the book, Malik has put together an excellent handbook – a recommended read and guide for anybody considering or planning an RTLS system.

Those familiar with the “for Dummies” series will recognize the format which is well structured by chapter with information boxes that make for easy navigation and selective reading. What follows here is a review of my personal highlights – this is not meant to be comprehensive nor does it follow the structure of the book (in fact it skips a number of valuable chapters.)

To be upfront, my one critique is that as the book was written in 2009 the advantages of newer versions of Bluetooth (specifically Bluetooth low energy/Bluetooth smart which merged into the Bluetooth Core Specifications in 2010) do not yet feature. But then again, that is what we publish our white papers for.

Ranging techniques and position estimation algorithms: RTLS for Dummies offers the best overview there is (Chapter 2)

This chapter offers the clearest breakdown of how RTLS systems actually get the blue dot on a map.The chapter clearly divides between ranging techniques and position estimation techniques. This distinction often gets lost in the conversation but is crucial for the understanding of the advantages and drawback of any system.

For the distance estimation Malik outlines the concepts of trilateration, triangulation, scene analysis and nearest neighbor – a recommended starting point for the evaluation of a given technology.

Yet, even more valuable is the breakdown of the ranging techniques. After all, trilateration and nearest neighbor (two very common techniques) take distance or an approximation as an input. If that input is useless, no amount of machine learning and AI will help. Hence, the importance of understanding the different ranging techniques is essential.

Here the simple and comprehensive explanation of Proximity, Time of Arrival, Angle of Arrival, Time Difference of Arrival, Time of Flight, Round Trip Time and Received Signal Strength Indication is highly recommended for anybody seeking a framework to understand and compare different technologies.

In RTLS for Dummies, the positioning estimation algorithm and the ranging techniques make up 12 pages but will help non-technical readers as well as readers new to the topic get a grasp.

RTLS for Dummies: The “tag” – a framework

Depending on the underlying technologies, different RTLS systems will work with different tags.

A lot rides on the tag as the user will work with them directly (especially if people are to be tracked) and key operational concerns such as durability, battery life or the ability to trigger events rest on the choice of the tag. Again, the book provides the reader with an excellent framework to understand the trade-offs between technologies and operational requirements.

Many of my daily discussions center around the tag. Their battery lifetime, replaceability of the battery, durability or price. A solid understanding of the trade-offs in tags in conjunction with the positioning algorithm is crucial to advise or implement a particular solution for a given stakeholder.

Given the timing of the book, the changes of Bluetooth Low Energy are missing here. Since Bluetooth Low Energy became part of the Bluetooth protocol family in 2010, a it has brought massive increase in battery life and cost per tag to the RTLS market. This is due to the massive economies of scale from the acceptance of Bluetooth in most consumer devices. This downward effect on the cost of tags and readers/gateways/hubs is the biggest change in the RTLS landscape in a while.

Use-case overview: RTLS for Dummies discusses more than infusion pumps and wheelchair tracking (Chapter 1)

Within the RTLS market, as probably in most new technology markets, a number of use-cases become a poster child (not to say “killer app”) for the technology. In RTLS these would be infusion pump and wheelchair tracking. Malik thankfully goes way beyond this by providing an excellent use-case overview by sector. Even more useful for those considering the implementation of an asset or people tracking solution is the guide to business case development and vendor selection at the end of the book.

Levels of accuracy (choke points vs room level) (Chapter 8 – 13)

In an earlier piece I argued that accuracy should be considered from a “jobs to be done” perspective or, in other words, the desired outcomes that underlie demands for asset tracking. In his book, Ajay Malik provides guidance on the concept of “accuracy” that should be considered for all jobs to be done.

Breaking down concepts of accuracy into Choke Point, Room Level, Presence Location by Association and Symbolic Reporting into the use-cases, relevant technologies and their drawbacks is an excellent framework in which to consider what metrics the RTLS system is designated to improve. Let me highlight this again: understanding how to apply the right concept of accuracy will be crucial to choose the right system for the desired outcome.

If the above paragraph made you curious about what “Symbolic Reporting” is, here is a snippet from the book, page 156:

“For many applications, you need to know the exact location of a person or asset; for others, your needs can be satisfied by just knowing what room a person or asset is in. This kind of location reporting — in which location is reported as an abstract idea of where something is — is called symbolic locating. Room-level locating is a prime example of symbolic locating; location is reported in reference to the room that a person or asset is in or near.”

Summary: Read RTLS for Dummies. Right now.

This is an excellent book, highly recommended for technical as well as non-technical managers, product managers and marketers as well as anybody interested in making sense of location – a key component of the internet of things.

There are several reasons to implement a real time location system. If you need help understanding the use cases, technologies, or, my personal favorite, the role of Bluetooth beacons, this white paper is both free and can help get you started.