As the Internet of Things begins to really take off -- Gartner estimated 6.4 billion connected "things" will be in use in 2016 -- mesh networking is increasingly being viewed as an appealing way to interconnect devices.
What is a mesh network? The answer varies a bit depending upon whom you ask, but the key is that mesh networks typically rely on wireless nodes rather than centralized access points to create a virtual wireless backbone. In other words, mesh networks wirelessly connect devices and computers directly without involving a phone company or ISP.
Network "nodes" establish network links with surrounding nodes, enabling traffic to hop between nodes on numerous paths through the network. This means that mesh networks are self-healing, self-organizing and scalable by simply adding more nodes. And, significantly, shutting a mesh network down involves shutting down each individual node.
The key concept behind Internet of Things (IoT) meshing is to enable connected things -- such as lights and thermostats that contain embedded sensor technologies -- to communicate without relying on PCs or dedicated hub services. This makes it much simpler to build a network of connected things and is, as a bonus, relatively inexpensive.
While IoT is mainly discussed in terms of home and building automation, mesh networks are ideal for supporting not only these but also other IoT low-power and low-data-rate applications such as industrial automation, monitoring medical supplies and other things inside hospitals, and even agriculture or oil and gas operations in some of the world's most remote locations.
There are plenty of options when it comes to creating a mesh network to connect IoT devices. Want to use a cellular network, Wi-Fi, the cloud or Bluetooth -- or none of the above? Odds are good that a technology either already exists or is under development right now that will fit your specific needs -- no matter how unusual.
The ZigBee Alliance and Google-backed Thread Group have both laid down a significant amount of the foundation within the IoT and wireless meshing realm, and are now collaborating to develop connected home products.
Many startups and established companies alike are working to address some of the biggest concerns with meshing for IoT -- namely security and privacy, scalability and complexity -- and are coming up with some incredibly innovative approaches.
Read on to learn how two startups and a Bluetooth industry group -- Filament, Helium Systems Inc. and Bluetooth SIG -- are changing the mesh networking game.
Filament, a Reno, Nev.-based startup, is helping industrial customers get legacy infrastructures online. Mesh networking is just one of many ways that Filament stands out within the IoT realm.
Companies can blanket industrial areas with Filament's wireless sensor devices -- a.k.a. "Taps" -- to build low-power autonomous mesh networks for data collection and asset monitoring. The devices feature built-in environmental sensors, USB for expansion, and are equipped with hardware crypto chips and long-range radios to provide accessibility and secure communication across large geographic areas.
Unlike most of its competitors, Filament's service operates within distributed environments, removing the need for a cloud or central network authority because it's designed to operate in areas without existing cellular or Wi-Fi networks.
In its fully distributed network approach, a radio sends data from one point to another, but doesn't actually do the mesh networking or routing. Mesh networking technology sits atop the radio and enables sending data wherever it needs to go within the mesh, whether it's one machine to another machine (M2M), to the cloud, or one machine to many akin to a multicast or broadcast.
How easy is it to get started?
"If a gold mine located in the Australian Outback wants their vehicles connected and communicating with each other for collision avoidance, with mesh networking they can just put the devices on their vehicles and start communicating immediately," said Eric Jennings, Filament's CEO. "If they were relying on LTE or Wi-Fi, they'd essentially need to deploy their own power."
Filament's transceiver gets approximately 9 miles' line of sight between devices, which enables coverage of large areas -- as in "an entire city-wide deployment, agriculture plots, manufacturing lines, or oil and gas pipeline or mines in remote locations," Jennings explained. But this number decreases with obstructions you might find in a city or inside a building.
One of Filament's key differentiators is its raw mesh networking capabilities coupled with a long-range radio, boasting true M2M communication or "mesh networking communication." In other words, two devices can establish a channel of communication and trust that doesn't require a central authority.
Filament discovered that companies' initial desire is often to connect manufacturing lines or fleets of vehicles, but there's a natural migration to wanting to analyze the data traversing the mesh. "Once we start talking about what comes next, they want to get insights into raw data coming off machines and do things like have one machine automatically send its calibration data to other machines," said Jennings. "These sorts of things start to be revealed once you move beyond the initial step of getting connected."
At a higher level, Filament doesn't offer a cloud option but by design supports several popular cloud providers out of the box, whichever one the customer opts to use. "Our product supports, but never requires, cloud connectivity," said Jennings. That's important for any operations without strong Internet connectivity.
Another aspect that sets Filament apart from its competitors is the way it sells and bills. The company doesn't sell its products outright but rather offers monthly or yearly service plans. Thanks to existing Bitcoin blockchain technology, receipt for payment is stored within the blockchain as immutable evidence that access to Filament networks is allowed. The identity and authentication of devices also refers to the blockchain as a "source of truth," and Filament-enabled devices can transact value using cryptographic micropayments. Also intriguing: If customers don't pay, the devices won't work, which is essentially pay-by-enforcement firmware.
"This decision was based on what customers wanted in terms of operational costs versus capital expenses," Jennings said. "Our pay-by-enforcement firmware is, to our knowledge, the only one. And if you're able to reinforce reoccurring revenue on a physical device ... it starts to look and feel like a product as a service model."
Not surprisingly, Filament also places a heavy emphasis on IoT security and privacy protection. "At the physical hardware level, a crypto chip handles secured storage of private keys for cryptography," Jennings noted.
One of the biggest IoT security concerns is that keys are often stored within the same area of the main microcontroller as the rest of the code and aren't even password protected. Filament, however, stores its keys "in a secure area where we can't even get them," Jennings pointed out. "It'd be very difficult to steal those keys."
Moving up a layer to the protocol level, Filament's CTO Jeremie Miller, also creator of Jabber, developed a protocol called "Telehash," a next generation of the XMPP protocol.
"Telehash encryption is never optional, it's always enforced by default so it can't be turned off," said Jennings. "It also won't leak any metadata between two endpoints -- whether it's device to device, device to person or device to cloud."
Another aspect of Filament's security approach involves perfect forward secret keys. "The encryption key rotates maybe every 10 minutes," Jennings explained. "So even if a nation state is recording a bunch of data, they'll only be able to decrypt the last 10 minutes' worth."
Helium is a San Francisco-based IoT company "making sense of your things." From wireless sensors to complex event processing, Helium offers businesses the "power of perception" by sensing temperature, motion, sound, pressure, moisture and more to intelligently increase efficiency, avoid loss from equipment failure and reduce downtime.
While Helium "doesn't do mesh networking," it was founded by guys interested in interconnecting things to the Internet. When they set out to build IoT devices, they encountered challenges bridging the gap between software and physical worlds. Their solution was to build a radio connectivity technology that now forms the basis of Helium's product offering, although it's since been expanded into a full-stack platform.
How long does it take to get set up? Helium's smart sensors -- network access points that are small pieces of network hardware -- can be unboxed and deployed in mere minutes. You get something that works and you can write business logic on top of it -- that's what Helium means by "smart sensors."
Right now, in terms of IoT, "the enterprise realm is mostly concerned about security and zero configuration ... that the platform 'just works.' This is the cornerstone of our offer," said Rob Chandhok, president and COO of Helium.
Its network operates at both 2.5 GHz and 900 MHz bands dynamically to avoid congestion with Wi-Fi and Bluetooth traffic. Whether deploying 10 or 10,000 sensors, Helium's goal is to make it easy to grow and manage the deployed network on demand, without restrictions or limits.
Once deployed, Helium's smart sensors use combined data to make monitoring both sophisticated and simple. All of Helium's edge components can be upgraded via software.
Unlike Filament's approach, Helium's cloud platform is an always-on, optimized infrastructure for managing flows of real-time and historical data at scale, such as monitoring the health of temperature-sensitive equipment. Machine learning is tapped to dynamically monitor for abnormal behavior, deliver real-time alerts and advanced analytics to ensure compliance with regulations.
"Our platform lets you reason about the data you're getting and do it both on single pipelines of data flow from a sensor to millions of those things happening simultaneously," said Chandhok.
Helium specifically focused on the user interface part of the application layer of the platform to provide components that do standard notifications and alerts -- management of the network -- or users can build applications to augment those components or bring it into their own dashboards through modern APIs. "We expect our strongest partners to embed Helium into their system because they'll have larger-scale systems, of which IoT will only be a part," added Chandhok.
Helium's biggest differentiation is perhaps being full stack. "We provide a platform that solves the entire problem so you won't be stuck searching for hardware and a place to host the compute," said Chandhok.
It's worth noting that the company also creates some of its own sensors, which is downright uncommon in the U.S. "We'll make a humidity or temperature sensor, ambient light sensors or proximity sensors, and a company like Siemens or Bosch will make specialty gas sensors or detectors or radioactivity detectors for certain industrial environments -- but they can do it basically atop our motherboard for this computing run time," said Chandhok. "Notice that I'm not calling it an operating system because it doesn't matter which operating system it runs on. It's like what Android did for smartphones -- it creates a framework."
Which applications are they targeting? Helium is already testing out the platform on its own via deployments. "The first one is a temperature monitoring solution for things of high value stored in refrigerators," explained Chandhok. "In particular, we're going into the hospital market for medicines and blood storage, oncology products and vaccines, and probably soon afterward into the food services industry for places that store high-end items."
Again, security isn't an afterthought. "Our sensors and our network are built on top of strong authentication and rely on encryption based on a hardware root of trust, so each of our modules at the edge has a hardware-stored key that's configured at the time of manufacture," Chandhok noted.
Helium also follows all modern practices of rolling keys and dealing with key compromises, and has protocols for updating keys. New tools are still being developed for dealing with tiny embedded devices, and "as more tools become available, we'll also explore those solutions," added Chandhok.
Bluetooth Special Interest Group (SIG)
If other approaches don't appeal to you and your heart is set on mesh networking via Bluetooth, don't despair. The not-for-profit Bluetooth SIG, whose 28,000 member companies produce and ship about 3 billion products per year, is working to develop a Bluetooth mesh networking standard that should be made available at some point in 2016.
"Some other standards for meshing right now are notoriously difficult to set up," pointed out Errett Kroeter, vice president of brand and developer marketing for the Bluetooth Special Interest Group. "Our goal is to keep mesh networks simple so that people will actually want to use them."
Why Bluetooth? For starters, it's ubiquitous -- Bluetooth is in everything from cellphones to car and audio products, computers and wearables.
"The next logical extension is being able to use Bluetooth -- it's everywhere and power efficient -- to link Bluetooth devices into a network that's not based on a hub and spoke architecture but really more of a mesh architecture," Kroeter said.
The benefits of a Bluetooth mesh network are that you can simply send a signal from one location and propagate it through a bunch of nodes. "Say every light in your house is Bluetooth controlled ... even if you wanted to send a signal from your basement upstairs to a window actuator or HVAC control, you could use a network of Bluetooth-enabled lights to enable that signal to hop along whatever endpoint you want to transmit it to or get information from whichever endpoint you want," explained Kroeter. "That's one of the key benefits of Bluetooth -- you can extend your range almost infinitely because you can just keep linking all of these things in the network." And, like other meshing approaches, it adds some reliability because the message travels on more than one path to the endpoint.
How easy is it to get set up? If you have a new set of Bluetooth-enabled light bulbs and a new Bluetooth light switch but don't want to mess around installing wires to the new switch, you can use an app on your smartphone to do the provisioning -- setting it up in a straightforward way. "Once it's all connected, you put your smartphone away and won't need to use it again as a remote ... the light switch will now work," noted Kroeter.
Which applications are Bluetooth mesh networking ideally suited for? "We envision it in a lot of different scenarios -- beginning with the home," said Kroeter. "It can be used for lighting, HVAC control, security control or environmental sensors like temperature or humidity. We'd like to see Bluetooth used in industrial and building automation scenarios. We're solidly entrenched within the consumer area, but we think mesh networking will allow us to create really good solutions in those other areas."
In case you're curious about how it scales, chip manufacturer CSR developed its own version of Bluetooth meshing and claimed a theoretical limit of 65,000 nodes on its network.
As with other mesh networking technologies, security and privacy are also central to Bluetooth SIG's vision of meshing; it frequently reminds manufacturers to bake it in from the beginning, and many of its members are in the EU -- where many are extremely concerned about security and privacy issues.
Bluetooth provides 128-bit AES encryption along with privacy protections so that a device's MAC address can be disguised and isn't repeating constantly so it can't be tracked from point to point. "We'll continue to evaluate other security upgrades that are deemed necessary, but right now we're using the industry standard security encryption algorithms and privacy standards," added Kroeter.
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