IoT 101: Active vs. Passive

Written by Keiley Ostrow
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This week we feature guest author Keiley Ostrow, IoT Program Manager for Cargo Signal. Cargo Signal offers global control and oversight of the location and condition of the products moving through your supply chain. Through active, real-time monitoring using advanced cargo sensors, Cargo Signal’s team of security and logistics professionals will keep an eye on your shipments and take steps to respond based on your priorities. Cargo Signal is a wholly-owned subsidiary of Expeditors International of Washington, Inc.

I just got a job utilizing the Internet of Things (IoT) and found the technical jargon to be confusing. You see, I’ve spent my career bringing new technologies to the logistics industry and I've learned that if I can’t explain what I do to my family casually over dinner, I don’t understand it well enough! 

Therefore, I set out to wrap my brain around all the technical terms like “RFID, BLE, passive, active, gateway, tracking devices, cellular, 2G/3G/4G/LTE, MTC, Cat-M1, NB1, Wi-Fi” to such a degree that I could explain them to my mom while chatting with her on FaceTime.

Please join me on this journey, via a four part series with our first two terms being active and passive.

An active device has enough power to tell you where it is. The most familiar example is your mobile phone. When you have it connected to the internet, it can tell you where it is on those occasions where you have temporarily misplaced it.

A passive device does not have enough power to communicate anything by itself, but it can capture information like temperature or heart rate. Many of the fitness wristbands available today are passive because they require an active mobile phone connected to the internet to gather your data and show your progress over time.

So, if I were to take a walk with my mobile phone, my friends could see my progress throughout the walk. If I wore my fitness wristband, my step count would be recorded and when I returned home to my phone it would then update my friends on the walk I had just finished.

Many industries such as the food and beverage or healthcare industry use passive devices in their supply chains for historical data analysis of temperature and to comply with regulations designed to ensure the things we put in or around our bodies are safe.

In fact, the terms passive and active are also used in the packaging industry to describe if the containers used actively maintain the temperature like a refrigerator, or passively retain temperature like a cooler.

When I bring ice cream home from the store in a “passive” cooler it is likely to be a quick trip with no other stops along the way before it is put into her “active” refrigerator at home. If I were to go on a long road trip in a RV, it’s likely that ice cream will be in an “active” refrigerator powered by the vehicle.

So let’s wrap things up with a pros and cons list of active & passive by use case: 


  Pro Con
Phone (Active) Talk to friends for motivation Unable to track heart rate
Wristband (Passive) Track body vitals Can’t compare to last week

Track Cargo

  Pro Con
Active Device Easy to get started Requires larger batteries
Passive Device Smaller form factor Still requires an active device at some point

In short - 

Active devices: Collect data and have enough power to provide the data and location in real time.

Passive devices: Collect data but do not have enough power to transmit data or location on their own. 

I hope this helps you better understand some IoT terminology, and if I’ve really done my job right, you’ll strike up an IoT conversation with your friends or family!

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Blog was originally posted on November 12, 2020 10 AM

Topics: Tracking devices, Security, technology, Temperature Monitoring

Keiley Ostrow

Written by Keiley Ostrow

Keiley Ostrow has more than 30 years of experience in logistics. Much of that time was focused on process improvement and leveraging technology to automate and increase efficiencies. She has led teams globally in ocean carrier operations, systems analysis, data analytics, software development, process improvement, technology implementations, and change management. Her latest endeavor focuses on leveraging the internet of things to automate operational processes.

5 minute read