SmartMesh IP products are wireless chips and pre-certified PCB modules, complete with ready-to-deploy wireless mesh networking software based on the 6LoWPAN and IEEE 802.15.4e standards. SmartMesh is the only network built for the stringent reliability and security required for industrial IoT and is engineered for years of trouble-free operation. Before discussing the new SmartMesh IP features, let us first examine the Wireless Sensor Network (WSN) requirements and competitive landscape for Industrial IoT applications.
The Criticality of Secure and Reliable Wireless Networks for Industrial IoT Applications
The Industrial Internet of Things (IoT) calls for wireless sensing and control nodes to be used in a wide range of applications from factories and industrial process plants to building energy efficiency, smart parking applications and commercial agriculture. In all of these applications, Industrial IoT wireless solutions are expected to operate for many years, often in harsh RF environments and extreme atmospheric conditions.
Unlike consumer applications, where cost is often the most important system attribute, industrial applications typically rate reliability and security at the top of the list. In OnWorld's global survey of industrial wireless sensor network (WSN) users, reliability and security are the two most important concerns cited.¹ This is not surprising if you consider that a company's profitability, the quality and efficiency with which they produce goods, and their worker's safety often rely on these networks.
For Industrial IoT applications, even a 1% data failure rate is too high, since it translates to 3.65 days per year of unscheduled downtime. Industrial IoT solution providers have noted that one half-day of communications outage would result in irate customers and the cost of an on-site technician visit. If a second such outage were to occur, there is a high likelihood of losing their customer. Therefore, industrial applications demand >99.999% data reliability to overcome the wide variety of RF problems they will likely experience over years of operation.
IoT Wireless Landscape
There are many wireless technologies targeting IoT, however each targets a different set of requirements and are not well-suited for the rigors of Industrial IoT:
- Cellular M2M networks are long range, but the wireless hardware consumes a lot of power, resulting in a practical battery life of hours. Cellular is expensive as far as hardware and recurring services are concerned.
- Low Power WiFi and Bluetooth Low Energy are best suited for nodes that must communicate with existing human interface devices (e.g. smart phones and tablets) and WiFi access points. However, the resulting sensor nodes are still too high power for multi-year operational life.
- LPWAN technology (e.g. LoRa, SigFox) targets long range sensor applications. Nodes can have multi-year battery life, however nodes must only send small amounts of data very infrequently (e.g. 1 message a day). With increased range, one must be wary of interference from neighboring LPWAN nodes and networks.
In none of these technologies, however, do suppliers target highly reliable performance. For example, instead of citing a reliability number, LPWAN providers explain they target applications tolerant of packet loss.
SmartMesh IP and Time Synchronized Channel Hopping for Robustness and Low Power
SmartMesh IP networks routinely deliver greater than 99.999% in harsh industrial environments² using a Time Synchronized Channel Hopping (TSCH) link layer. TSCH is a technique pioneered by Linear Technology and a foundational building block of wireless mesh networking standards, such as WirelessHART (IEC62591), IEEE 802.15.4e and IETF 6TiSCh.
In a TSCH network, all motes in the network are synchronized to within a few microseconds. Network communication is organized into time slots, which enables ultra-low power consumption through very low duty cycling (each node knows precisely when to transmit, receive, or sleep). The use of timeslots enables channel-hopping for communications robustness. Most other WSNs suffer from network self-interference (i.e. two nodes may transmit at the same time), preventing them from scaling. However, since TSCH network traffic is scheduled, there is no network self-interference, enabling dense, overlapping networks.
Large Networks and Roaming Nodes
SmartMesh IP now offers an even wider range of features, including:
- Scalable Network and Security Management: SmartMesh networks self-form and self-heal and continuously self-optimize while providing NIST-certified security. Network Manager options include the cost-effective on-chip EManager for networks of less than 100 nodes, and the new VManager. VManager software reliably supports over one thousand nodes in a single secure network and runs on an X86-based Virtual Machine (VM) that can be located anywhere with an IP connection, including the Cloud. VManager is described in technical detail in a short video.
- Ultralow Power Roaming Nodes: The new Blink mode addresses applications where nodes may need to move in and out of the mesh and send data several times per day. Thousands of SmartMesh IP Blink nodes can reliably and securely send data into a mesh-mode SmartMesh network while consuming an average of less than 3µA of power.
As Industrial IoT applications grow beyond small and medium early pilot tests, demand is increasing for the WSNs to accommodate highly reliable and secure large networks. For more details, visit Industrial Wireless Sensor Networks: Trends and Developments.
About the Author
Ross Yu is the Product Marketing Manager at Linear Technology for the Dust Networks product line. Mr. Yu and his team at Dust Networks have made significant contributions to solving the challenges inherent in the exciting field of wireless sensor networking, and Mr. Yu has been instrumental in bringing to market the industry's most reliable and lowest power wireless mesh sensor networking solutions. Mr. Yu holds a Bachelors of Science degree and a Masters of Engineering in Electrical Engineering and Computer Science from the Massachusetts Institute of Technology.