Intro to WSANs

With all the talk over the past couple of years of Wireless Sensor-Area Networks (WSANs), you might be wondering what all the fuss is about.  Why is low-bandwidth wireless so hot all of a sudden?  How can it help my company?   The answer is that low-power mesh-networked wireless may be the pathway to an entirely new revenue-stream with very little investment.  Read on for a primer on SAN wireless, which is used for data collection and remote-control all types of devices, including yours!

Wireless Application Areas

WSCANs – The Basics

Wireless Sensor-and-Control-Area-Networks (the WSCAN nomenclature is gradually replacing WSAN, mentioned above) are low-speed, low-power, high-reliability wireless networks used for telemetry collection and non-real-time controls.

There are dozens of proprietary solutions to choose from in order to create such a wireless infra-structure but, if you consider only the “open” standards, there are just a few primary players, which include: Zigbee Pro, ZWave, 6loWPAN, Insteon and One-Net.  These are the names of the protocols – many of them operate on top of a IEEE 802.15.4 communication-standard layer, such that they may share basic operating frequencies, but they aren’t compatible with each other at the point the various systems are exchanging packets of information.

There are plenty of in-depth comparisons available on the web which pitch the pros and cons of each protocol, so I’ll just give you the big-picture conclusions.  Zigbee, one of the first “mesh-network” protocols (defined below) enjoys some of the most corporate and overall support and will probably be a major player in industrial, commercial and remote-control devices for the next decade, at the least.  In another article, I’ll discuss some interesting advantages of 6loWPAN which might make it a primary choice for lower-cost devices.   But no matter the protocol chosen, the low cost of the WSCAN components and the supporting microcontrollers, in addition to the ready availability of the networking protocol software (the so-called “stack”) have greatly decreased the barriers-to-entry in the provision of such data-delivery networks.

So, what exactly are we talking about?  WSCA Networks consist of “nodes”, or wireless access and interchange points, which are attached to devices (such as sensors, valves, motors, compressors or exchangers, as examples) and which collect data such as temperatures, pressures, movement, device status… any type of low-bandwidth data your device generates…. and relays that information to a central data-aggregator, for visualization and analysis.  The visualization and analysis portion is typically automated, so it’s not as work-intensive as it sounds… it’s typically tackled by a SCADA system, which is just a front-end reporting module for all the data gathered within a process or set of processes.  Inductive Automation is one such SCADA solution, particularly attractive for its scalable cost-structure.  A separate article will address decision-making for SCADA solutions.

Finally, WSCANs typically come in three topologies: Peer-to-Peer, Star and Mesh.  A star topology greatly simplifies the network overhead messaging and memory requirements, lending itself to lower-cost devices or controllers.  Mesh topologies, because of the inherent, multi-hop functionality of the contributing nodes, can span very large areas, on the order of kilometers, but require much larger memory capacities and processing power at each node, driving up cost.  The demands of the various protocols must be weighed against the capabilities and subsequent costs of the various hardware solutions in order to arrive at an optimal solution.

Who Needs WSCANs?

Not everyone needs a bunch of data streaming back and forth from their products.  But just about every high-tech device generates information during its operation, the monitoring or analysis of which may save your customers money or time.  Sometimes new markets can be created, parallel to your standard offerings, by simply adding wireless capabilities.  Here are the most compelling cases for integrating smarts and wireless:

The Monitoring of Data Will Allow My Customer to Avoid Catastrophic Failures

All equipment fails at some point.  If you sell industrial or technical equipment upon which your customer is relying for processes on a fabrication floor or in a lab, your customer wants to know when their equipment will fail before it happens.  Just as importantly, they’re no longer satisfied with maintenance operations and schedules which are inefficient and reward the supplier (you) for that inefficiency.  Your customers don’t want to replace a compressor every 20k hours, even if that solves their failure problem, primarily because that solution causes an efficiency problem.  Compressors, as an example, are expensive, so customers only want to replace them if their failures are imminent.  Long-term monitoring of output current, voltage, rpm or other characteristics can tell them when the compressor is starting to fail and allow high-efficiency maintenance based on a “replace on demand” approach, leading to an adoption of products which can supply such real-time status data.

Remote-Control of My Product Will Save My Customer Time

If your customer has a bunch of your gizmos in their operations, the manual gathering of all that data from each location takes a lot of time.  You can add remote controls and data gathering using a wired approach, but that takes additional infrastructure and isn’t very scalable or flexible for re-arrangements and expansion.  Your customer will love the time-saving and flexible aspects of wireless remote-control and status monitoring.

Remote Monitoring Will Allow My Customers to Save Money While Achieving Higher Quality

By routing process-related data (temperatures, pressures, viscosities, color) into a SCADA or other manufacturing-data aggregation system, customers can view exactly where processes deviate from acceptance levels and correct problems without spending a bunch of time troubleshooting.  They’ll save money while achieving higher quality…and they’ll love you for it.

Any of the above are excellent ways to make happy customers and create more sales for you.

Who Should Avoid Wireless?

There are some applications for which wireless is not a good fit.  Those applications fall primarily into these categories:

Real-Time Controls

Because of the time-delay of node-to-node messaging with handshaking and “message received” overhead on a relatively slow network, if you have controls with requirements for tight timing, like on the order of tens of milliseconds, wireless is not for you.  You’ll need a wired solution that can respond more quickly.

Critical Controls

Through message-path redundancy, handshaking and receipt verification, WSCANs are becoming more stable and robust all the time, but it’s still susceptible to ambient electro-magnetic noise.  Critical life-supporting equipment or equipment which could cause damage to people aren’t good fits for wireless.

Summary and Next Steps

The bottom line is that WSCANs increase availability, use-ability and efficiency of many types of equipment and devices, so they save your customer time and money.  Furthermore, customers have started to expect more and more data and controls availability from their equipment.  While wired solutions are great for mission-critical applications, their physical installation, configuration and maintenance overhead make them inflexible and expensive.  Self-healing, self-configuring WSCANs offer the lowest-cost, lowest-complexity and most flexible data-gathering and controls solution.

Capture Product Development has developed a WSCAN platform which allows rapid addition of WSCAN functionality to your product.  If you’d like to discuss how WSCANs can create an entirely new revenue stream for your company, please call or write today.  Experts are available to discuss your requirements today.