IoT in the real world: 7 things to consider when developing a cellular-based Industrial IoT solution
Successfully developing and deploying an Industrial Internet-of-Things (IIoT)
"connected" solution requires a coming together of a multitude of disparate technologies and engineering disciplines. Deploying even a relatively straight-forward cellular-based IIoT solution can involve solar, wireless, edge computing, MEMS, field I/O, extended temperature operation, etc., and that's before you add in the web/cloud/server side of things (not to mention all the 3 & 4 letter-acronyms you going to have to learn). In order to minimize time-to-market it is essential to ask the right questions and choose wisely when it comes to technology platforms, partners, and vendors.
The pointers below, for what it's worth, were gleaned from a ground-up development of an end-to-end IIoT architecture that is now successfully deployed in a variety of industrial vertical markets. The platform developed uses both cellular and "local" wireless technologies to maximize data collection capabilities while minimizing the cost of connectivity. All that said, here are 7 things you might want consider when it comes to deploying an IIoT solution in the real-world:
1. Cellular technology: build or buy
For a cellular-based solution you obviously need a cellular radio or modem. There are a number of options for implementing cellular connectivity in your IIoT application. For starters, you can use an external cell modem (quick but expensive), a USB stick modem (a decision you will regret), a modular embedded cell modem (more work but more cost effective), or fully embed a cellular radio in your design (lower cost for high-volume applications; high up-front costs and increased time-to-market).
In our experience external cell modems are fine for proof-of-concept and prototypes but are too costly for most applications and defeat our customer's desire to have a single, integrated IIoT device.
Depending on the volume of your application and how many cellular-enabled devices you plan to deploy you may be considering fully embedding a cellular radio into your design. If you're confident of your volume projections and you've got in-house RF and certifications expertise, this may indeed be the way to go as the long-term, per unit cost would be lower. However, certifications (PTCRB, FCC, etc.) are expensive and RF design/testing can be a non-trivial engineering exercise.
Many of the IIoT vertical markets we serve are 1,000's of devices per customer; not 100,000+ pieces like some more consumer-oriented IoT products; the kind of volumes needed to justify certifications costs. Alternatively, there are number of modular, embedded, pre-certified cellular technologies available that can get your product to market faster and with little or no certifications cost. We chose to adopt an embedded modular approach partly for these reasons, and also because it allows us to readily support multiple North American and International carriers (AT&T, Verizon, Sprint, Vodafone, etc.) all as a simple product build-option.
2. Clouds, carriers, and connectivity: make sure everybody can get along
Cellular enabled IIoT products require a connection to a carrier in order to get to the cloud. The big cellular carriers (Verizon, AT&T, Sprint) will certainly sell you an M2M plan for your IIoT device but most M2M devices have historically connected through Mobile Virtual Network Operators (MVNO) rather than the big carriers. MVNO's resell value-added connectivity plans that let you connect to one or more of the big carriers. One of the reasons many M2M connections go through an MVNO is because the big guys don't do M2M/IIoT very well, at least not yet, and the MVNO guys specialize in it and have for years (and in our experience are much easier to work with). These MVNO's can connect you to most any of the networks and can also offer better connectivity and reporting on data usage across networks. Additionally, with an MVNO you will have more options for server/VPS providers and more flexibility when it comes to connectivity options (static IP, private static IP, VPN, etc.).
3. Fast or Far? Choose your short-range wireless technology wisely.
A typical IIoT application for us involves not only wireless cellular technology but also a complimentary "local", license-free wireless technology as well. We combine both into a single product allowing us to collect data from multiple nodes at a site and then send that data back via a single cellular uplink to the cloud.
For example, for a school crossing light application, we monitor and control several "node" controllers from a single cellular "gateway" utilizing local wireless technology that covers the entire site. We can monitor and control multiple LED beacon lights positioned around the campus, monitor battery & solar status for each beacon, and update lighting schedules all from a single cellular link. This saves on both hardware and data plan costs.
In an applications like lighting control, tank farms, vessel monitoring, etc., you're not sending a lot of data over the local wireless link (think kilobytes not gigabytes) so it's important to realize that more times than not range is king; not bandwidth. Bluetooth and WiFi are great for certain applications (we offer both) and they can provide lots of through-put but long-range wireless is needed for many real-world IIoT applications (think miles not feet). For most of our applications an on-board 900MHz or 2.4GHz long-range radio technology proves to be a much more effective all around solution than Bluetooth or WiFi.
4. We've got the power...or not
Since a cellular-based IIoT application often implies remote connectivity there's a good chance it will use battery, solar, and/or a combination of a solar/battery power sources.
If you need solar you should arguably integrate a properly-designed solar
controller into your product and not source some cheap-ass, off-shore solar controller just because it's...well...cheap. Most of these off-the-shelf solar controllers have poor build quality, little to no revision control from lot-to-lot, and very few implement more advanced energy harvesting concepts like Maximum Power-Point Tracking (or MPPT).
After seeing many competitors and/or customer implemented
solutions struggle with quality issues from cheap, sourced solar
controllers or modules we chose to integrate an on-board, 3-stage solar
controller with MPPT into our product. The MMPT helps extract maximum
energy from solar panel and having an integrated solar controller minimizes
wiring and reduces the overall footprint of the solution. Additionally, we have far greater quality control over our solution.
With solar you need a battery and unlike your cell phone (which probably gets
charged daily) your cellular-enabled IIoT device may need to go days or even weeks without benefit of a charge. Also, depending on the location and time of year you may only get 3-4 hours of "good" sun each day even when you do have good sunlight. As such, you'll want to have a solid understanding of your power requirements and size your battery(ies) accordingly.
With regard to battery selection, battery technology has come a long way and
their are a lot of technologies and chemistries to choose from. Requirements for size and energy density may drive you to use a more cutting-edge battery technology but in general simpler is better. For one thing, you or your customer are going to have to replace that battery (or batteries) at some point. If your solution uses a chemistry or form-factor that is less common a replacement battery may be hard to come by. Whether your power requirement is a simple 9V battery or a bank of 12V SLA batteries be sure to consider costs, availability, and field-replaceability for both you and your customer's sake.
5. Weather the extremes
Most if not all of our IIoT solutions are deployed outdoors and in most every part of the U.S. and few other countries/continents as well. Our products have to work in a wide-range of temperature and environmental conditions. As such, we typically design all of our products to operate from -40 to +85 deg C. We also have to insure that our sourced products (and any external devices that your product has to connect to) can operate over the specified temperature range as well. We commonly work with customers who previously tried to use commercial-grade technology (think USB cell modem sticks, etc.) to implement their cellular-enabled IIoT solution on-the-cheap only to find that Mother Nature had other plans.
Most people have some idea that electronics and heat don't get along but cold can be just as much of a problem for poorly-implemented IIoT devices. Clocks run slow (if they run at all), processors don't boot, storage devices stop working, etc., not to mention possible issues with condensation and ice. As a result, we implement low-temperature testing/qualifications on both our products and sourced components and also utilize conformal coating, etc., as needed to meet customer's environmental requirements.
6. 24/7/365: always at the ready...
IIoT applications are mostly 24/7/365 affairs. Just like Waffle House, you're always open for business. For designers of industrial and other high-reliability systems this is nothing new but cellular-based IIoT solutions present some additional challenges to consider. Cell service can go down or your cloud server may be offline for a time. Your remote IIoT device needs to manage these connection issues gracefully. If you're collecting data then it needs to be retained and sent to the cloud when cell connectivity is restored or when the server comes back on-line. As such, you need to build intelligence into the local processing (or "edge") portion of your solution as well as provide for sufficient local storage.
7. Sure we do IIoT...
Anybody can spell IIoT but few actually specialize in well-integrated solutions. Vendors are racing to put "IoT" in front of everything they sell from processors, to sensors, to Bluetooth modules, to cell modems, to displays, and more. These components are common to most any embedded system and few of them provide intrinsic IIoT value in and of themselves. From solar to cellular, RF to I/O there are a lot of disparate technologies that need to seamlessly come together to create a successful IIoT product in a time-frame and at a price-point that can win the market. Successful IIoT product designers need to understand how all this diversity of components come together or work with a solution partner who's actually deployed an end-to-end IIoT solution.
IIoT: IoT products for the real world...
Industrial IoT solutions are already generating value and gaining commercial traction. In other words, many of these solutions are already in-the-field, they're working, and most importantly, customers are buying them. From traffic & safety, to vending, to logistics, to oil & gas, IIoT solutions are adding value by protecting and better utilizing high-value assets and providing a solid ROI for the customers who deploy them. It may be "wearables", "biometrics", and even "Internet toasters" that are generating much of the IoT "buzz" but the Industrial IoT market is quietly leading the charge of solving some real-world problems and giving early adopters an actual return on their IIoT investment and a competitive advantage to boot.