Cargo Signal Blog

IoT 101: Active vs. Passive

Cargo Signal Blog Assets3 IoT Active Passive

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: 

Exercise

  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 summary:

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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