Intermittently Connected IoT Devices for Logistics Quality Assurance

Philip Piletic
Logistics, QA, IoT
Illustration: © IoT For All

Supply chain stakeholders have extolled the virtues of data loggers for some time now, but most of the off-the-shelf options currently on the market are designed to be constantly connected to the Internet. Everything from RF interference to network strain can cause these devices to suddenly stop functioning, which is a serious issue for those who depend on them to provide needed information.

Worst of all, most logistics companies that need this kind of technology aren’t able to afford such extravagances. Most of these firms would be better off with data loggers that only have to periodically sync to the net. Devices that tolerate unsynced data and send periodic updates might be the most effective in many situations.

Shifting Toward Intermittently Connected Data Loggers

Even the most stable Ethernet-based network connection is going to have some service disruption eventually. Whether it’s caused by hardware failures or increased demands for bandwidth, it can wreak havoc on devices designed to sync all of their information in real-time. 

The irony is that in most cases, there’s no reason to have literally up-to-the-minute data packets sent to their central servers. If a shipment is being tracked, then it normally only needs to report its location at each waypoint along a journey, or at the most, hourly updates. Everything else along the way is functionally the equivalent of digital static.

What’s more, constant updates can put an additional strain on existing network infrastructure. It might seem counter-intuitive, but more traditional package management technologies arguably work the best. RFID tags are still among the most widely used solutions in the logistics industry, and they rely on nothing more than simple radio waves that transmit data back to individual control centers.

Unfortunately, they don’t work well in extremely cold conditions, which can cause problems for those who have to move certain types of sensitive products. Most notably, logistics firms that ship vaccine doses on behalf of pharmaceutical clients have been unable to use RFID tags alongside packets of dry ice, which has unfortunately encouraged some to switch to always-on IoT devices that transmit a non-stop firehose of data signals.

According to Finnish technology firm Logmore, QR code-based data loggers are a better solution in these situations. These tags are attached to small sensors placed into a dry ice container, which then transmit data to small screens placed on the top of whatever container is carrying the shipment. These screens then flash a QR code, which can be snapped by anyone holding a compatible device.

Considering that even low-end smartphones can read QR codes, people should work with these sensors even in areas with relatively sparse connectivity infrastructure. This is a critical consideration among cold chain logistics companies involved with the shipping and storing of vaccine doses to deal with the novel coronavirus.

Relying on Intermittent Data Streams to Tackle Difficult Tasks

Simple and reliable IoT solutions are of great value when working with delicate materials. Even durable USB-based sensors will cease to work when they’re out of their designated service area or if they’re moved around too much.

That’s why so many firms have switched to managing data on an intermittent basis as they struggle to move delicate supplies related to the pandemic. The server-side activity has proven just as important when handling these cases, with some companies turning toward data marts as a way of processing information. 

A data mart is essentially an abstraction representing a subset of the information stored within a data warehouse that’s useful for a specific part of an enterprise. A central archive like this could hold all information collected from IoT devices across an entire network in this type of Applications. At the same time, a data mart might then provide information on specific shipments. 

This can help to dramatically reduce the amount of time needed to search a central archive when trying to find out more about the current location and status of a particular package.

Despite all of the precautions that shippers take, there’s still a good chance that something could end up getting damaged because of just how volatile vaccines and other condition-sensitive types of cargo are. Some experts have opined that around a quarter of all pharmacological shipments still end up in an unusable state. Knowing the probability of any particular piece being damaged from the beginning is extremely useful, and technicians can learn this simply by reading up on shipping statistics stored in their department’s data mart. 

When these types of data insights are paired with a simple intermittent transmission system, like QR code-based loggers, logistics experts can find information even if a portion of the logger sustains damage. This isn’t true of more sophisticated options, which might suddenly cease sending data and not provide users any way to recover useful information.

Even those based on efficient open-source frameworks could run into these kinds of problems. Because many IoT devices have limited power supplies, challenges often arise when it comes to battery capacity, which intermittent connectivity equipment can help solve.

Efficient Power Use When Dealing with a Data Firehose

If a logistics firm uses IoT gear that constantly transmits a never-ending stream of data, then there’s a good chance that all of their equipment will have to be hooked up to a stable source of power. This isn’t an option for packages locked away in dark train cars or the internal holds of cargo jets. Once a lithium-ion battery exhausts itself trying to keep up with an always-on cellular connection, you’ll be out of luck.

Unless they’re built into appliances made for home or office use, almost all IoT devices have limited power supplies, which makes efficient usage of paramount importance. Data transmission avoidance is the easiest way to conserve power since Wi-Fi and cellular links are based on RF technology and therefore drain batteries considerably. Some developers have adopted what they call a “push paradigm” to deal with the issue.

This approach completely avoids transmitting data unless it’s necessary. While you do need to have regular updates to ensure that data stays synced with a mart or warehouse, most companies actually don’t need the firehose of information they’re receiving. Short periodic packets featuring XML or JSON payloads will keep databases on track without wasting batteries.

This can also help to dramatically reduce network loads, which is important for shipments that might be passing through areas with poor connectivity. Engineers have developed new protocols, like the Low-Power Wide Area Network system, to further improve the way that these devices talk to central servers.

Complex communication profiles often exacerbate network stress. Technicians who try to send a firehose of data that features a great deal of header information will quickly run into real problems. When working with something as delicate as food, electronics, or medicine, it’s important to reduce the amount of information sent and encapsulate it in the most straightforward format possible.

Though engineers might be consistently looking for new solutions to these problems, the most robust and fault-tolerant intermittent data transmission techniques will likely prove themselves useful in the widest array of Applications.

Philip Piletic
Philip Piletic
Editor of Love marketing & tech.
Editor of Love marketing & tech.