Cellular Puts the “2” in M2M

Sensors Insights by Scott Schwalbe

Intro

The genius of the Internet was, and still is, the linkage of people and their accumulated data into one universally accessible, global knowledge base. Ideas that previously might never have intersected can now come together, generating new concepts and directions for innovation and producing the whirlwind pace of change we now take for granted. The underlying information was always there, but separated into silos it was unable to generate the next generation of ideas unless and until the individual ideas were disseminated either through traditional means in print or at conferences or simply spread by accident. For good reason, the Internet became the medium of choice for instant transmission of all sorts of information, from stupid pet and human tricks to life-changing technology.

Today a similar transition is taking place for machine generated data, more-or-less independent of human intervention. M2M, the technology underlying the emerging Internet of Things, allows systems to independently collect data and transmit it to other systems, to databases, and to human recipients. The data typically travels along human-defined pathways, but much of the decision making about what to send and when to transmit is entrusted to the systems themselves. The result is systems that can make decisions based not just on local input but on input from a far-flung network of sites and sources. This networking can operate on virtually any scale from systems in a home to those scattered around the globe, and the result, regardless of scale, is smarter, faster, more economical operations.

In terms of architecture, the name, M2M, says it all. The first "M" is the vast catalog of sensors collecting data at its source, be it electrical, chemical, mechanical, etc. The other "M" is the receiving systems—relays, dashboards, or complex software systems—that get and act on the sensor data. And the "2" (to) in between is the connectivity that transmits the data from source to destination. In a sense it's the "2" that defines the technology. Sensors and data systems have both been around for years; it's their new-found ability to speak to one another that is producing the Internet of Things.

There's really nothing new about the concept of fully- or semi-autonomous machines. Thermostats and governors date back to the 19th century. As far back as the 1880s electric thermostats featured rudimentary machine-to-machine connectivity, sending on/off signals by wire from a living space to a boiler in another part of the building. Of course today's smart sensors can capture and measure more kinds of data more accurately than ever before. And data systems receiving that information can make more sophisticated decisions concerning its use. But the essence of M2M is still the automated communication of data from one system to another.

Over a short distance, data connectivity can still be as simple as creating a wired connection. Data can also be wirelessly sent over short distances via Bluetooth, Wi-Fi, or other specialized radio frequency connections. Over longer distances the data can hop onto the Internet, cable, or the public switched network using a wired connection or wireless connection. But for quick, easy communication to just about any fixed or mobile location it's hard to beat the cellular network. Its voice channels cover most of the populated world, and the signaling channel used for transmitting data reaches even to places where voice connections can be spotty. In other words, while some locations and situations offer a variety of wired and unwired data connectivity choices, cellular works almost anywhere. And a data-only (non-voice) connection can be very inexpensive to implement and use. But the biggest advantage of cellular may be the speed with which it can be implemented, both by the product developer and by the end user.

For cellphone-savvy users, cellular connectivity is both familiar and easy, and cellular-enabled products can literally be up and running minutes after they come out of the box. The bigger challenge faces product developers: getting cellular connectivity into the product and maintaining, as far as possible, the first-mover advantage that helps ensure market leadership while maximizing profit margin and product life.

Getting There Fast

There are several challenges facing the developer who wants to add cellular capability to a new product. The first is the modem itself. Possible cellular modem configurations range from external boxes to embedded solutions. External options can be quick and easy, but they aren't always pretty.

"Chip-down" internal solutions can be tidy and compact, but their design can eat up development resources and the high labor cost of development from scratch can only be justified over large volume sales. For a developer, the neatest and most economical solution may be a ready-made embedded cellular modem designed that can be plugged into the product's circuit board. Key selection criteria include size, flexibility, and cost.

The second issue is speed. The "first-mover advantage" applies in virtually any market, but it is particularly valuable in technology fields where change comes quickly, product life can be short, and the best profit margins come early. Second-place market entrants work just as hard to get their products to market as those who arrived first, but they are competing for only part of the market. Those who come after that can end up fighting for scraps. The trick is to define the market with an innovative product, get there first, and take and hold the high ground.

When time is of the essence, as it certainly is in the fast-growing Internet of Things, you want to focus as much of your time as possible on creating what is new and unique and as little as possible on reinventing the wheel. The modems and gateways required for cellular connectivity already exist; your job is to identify options that best meet your needs and, if appropriate, the outside expertise needed to incorporate them into your product. The more pieces—modem, gateway, cell service, design expertise—you can find in one place, the less energy you'll have to put into coordination and the fewer cracks for things to fall into.

The next issue around cellular connectivity is FCC certification. Anything that accesses the public airwaves needs it, and getting certified can take lots of money and time. A pre-certified modem or a gateway containing a pre-certified modem will eliminate additional costs and delays and help you focus internal resources on getting to market sooner.

And finally there is manufacturing. The perfect prototype may win you a pat on the back, but it won't earn your company a dime. Unless you have internal manufacturing resources or know where to find them, a trustworthy guide can help you balance cost, speed, and quality and bring a competitive product quickly to market.

For developers considering cellular networking for connectivity there are a number of factors to consider:

  1. The right cellular technology for your application
  2. The right technology for accessing the chosen cellular network
  3. Whether the cellular aspect of your project is one you want to outsource and, if so, what to look for in a partner.

Choosing Cellular Network Technology

Your choice of cellular technology depends on the available networks and the data throughput you will require.

2G GSM and 2G CDMA

2G is second generation cellular technology in which all signals are transmitted in compressed digital form. Digital technology allows multiple messages to be transmitted in the bandwidth that would otherwise be occupied by a single analog call. The original data speed of 2G was around 9.6 Kb/s, but has expanded to what is sometimes called 2.5G, to speeds of up to 150 Kb/s.

2G comes in several flavors. 2G GSM and 2G CDMA are competing standards. CDMA is used only in North America, while the rest of the Americas and the world use GSM. CDMA stands for code division multiple access and offers somewhat better range and clarity in voice calling than GSM, but that doesn't really matter for data communication. GSM stands for global system for mobile communication. Unlike CDMA, GSM stores subscriber and wireless provider information on interchangeable SIM (subscriber identification module) cards, allowing users to switch phones or providers by replacing SIM cards.

3G GSM and 3G CDMA

3G or third generation cellular technology supports data speeds up to 3 Mb/s and, like 2G, comes in CDMA and GSM versions. The US uses both CDMA and GSM versions of 3G technology although US GSM is not compatible with the 3G GSM used elsewhere in the world. 3G CDMA (CDMA EVDO as opposed to CDMA 1xRTT used for 2G) is used exclusively in the US. Much of the rest of the world uses 3G GSM.

LTE

LTE, sometimes referred to as 4G LTE supports data speeds up to 100 Mb/s. While LTE can be implemented over several different spectra, compatible devices should work across all LTE spectra around the world. Its high throughput rate makes it ideal for streaming data applications like video and other high-volume processes.

A brief comparison of cellular technology useage.
A brief comparison of cellular technology useage.

Choosing Cellular Access Technology

There are a variety of ways to incorporate cellular connectivity into a product or device. Key issues affecting your choice include location as a factor in cellular network availability, product size, available expertise, time, cost, and your anticipated technology roadmap.

  • Consider the cellular network you will be using. If your product will have to access a range of network technologies, you will need to be able to support a corresponding range of cellular modems.
  • If size is an issue, as it almost always is today, external modems will not be a viable option. Even some internal modules/modems may be too large to be practical.
  • Consider what components are built into the modem itself and what will have to be configured separately to make the module/modem work.
  • If you have the time and resources you can design a cellular module into your board. Or you can streamline the process by incorporating a ready-made pre-certified modem. Designing in a module will take engineering time.
  • Products that access the network must have FCC certification, which can take months. Designing in a pre-certified cellular modem eliminates the cost of obtaining certification and allows your device to be immediately activated on a network, reducing risk and speeding ROI.
  • A plug-in modem with a complete development kit will further streamline the process.
  • Cost has many components. In comparing cost of various cellular access options, look at development cost versus purchase cost as well as manufacturing and operating costs. Also consider the cost of obtaining certification if your product is not pre-certified.
  • The volume in which you will produce your product also helps determine your platform options. Designing a module into your board (as opposed to plugging in a certified modem) can make sense when the cost can be amortized over very large volumes (and when you can support the up-front cost). When your volume is less than huge, however, or when you need to pay as you go, purchasing modems makes more sense.
  • Finally, consider the trajectory of your product's future development. If you expect your cellular needs to change—in speed, in network technology, or in related capabilities such as GPS—consider buying rather than building. It's easier to change direction when that means buying a different product rather than having to develop a new one yourself. This is especially true if the modems you buy use a standard form factor that allows easy swap-out as generations change.

Using a pre-certified modem saves time and money.
Using a pre-certified modem saves time and money.

Choosing a Partner

When the entire operation of a device or system depends on the performance of individual components you need to know that you're getting the capabilities you need, that the components will work in your architecture and your application, and that you'll have access to technical expertise when you need it. Purchasing departments can be valuable in choosing among viable options, but technical staff needs to decide what is viable in terms of vendor capabilities, specifications, and determining which providers can actually deliver the necessary capabilities. This is particularly true if the provider will be involved in a product's development.

Even if the relationship will be short, look for the same things you'd look for in any team member. Expertise and specialized knowledge will be critical, but so will the ability to listen, understand, and work with the rest of the team. And, when time is critical, you'll want to know that your partner shares your sense of urgency and can deliver the resources you need when you need them.

Examples

Because it is omnipresent and easy to install, cellular signaling will work in almost any sensor-connectivity application, but there are some in which it is the obvious, even the only choice. Because agriculture tends to take place far from infrastructure, the cellular signaling channel enables sensing applications that might otherwise be difficult to support.

Take for example the brooder barns in which young turkeys are kept in tightly controlled conditions of temperature and humidity. Sensors can easily track those conditions, but reporting those conditions and sending real-time alerts to off-site locations if conditions exceed critical thresholds can be a challenge. Cellular provides easy, affordable connections where wired connections don't exist and other wireless connections can't cover the distance.

Even more challenging are soil-moisture sensors in the middle of farm fields. Designed for irrigation management, these can be located far from both communication lines and AC power. Low-power cellular gateways can run on batteries and access the cellular network to upload information on underground moisture levels without requiring any live presence at all.

Clinics typically keep thousands-of-dollars-worth of refrigerated vaccines on hand. Refrigeration monitoring systems need to regularly upload temperature data and send alerts if cooling is lost. The cellular network is typically more reliable and easier to access than phone lines, and a cellular gateway can run on its own battery when commercial power goes down, which is one of the most common causes of refrigeration loss.

About the Author
Scott Schwalbe is the CEO of Nimbelink. In addition to a MBA from Cardinal Stritch University, he has 15 years of executive leadership experience, developed while serving 20 years in US Navy executive operations and business development roles at Celestica, HDM, and Logic PD. Scott is responsible for overall leadership of Nimbelink.

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