IoB Insider Rob Bamforth of analyst company Quocirca, on why the time has come for commercial IoT applications to use the mesh technologies more commonly deployed in emergency and combat scenarios.
Many IoT applications look great when first presented. Low-cost processing power and storage, coupled with the pervasive availability of open networking, should in theory make almost anything possible. The challenge comes when trying to turn this combination into real business solutions. Security is an ever-present and justifiable concern, but for many use cases, the biggest issue is scale.
The IoT scaling challenge is both technical and financial: one is up, the other is down.
In other words, much of the need to scale down financially appears to have been tackled as technology has been commoditized. This helps, but as they move from concept to reality, most IoT applications increasingly rely on a sizeable investment in software, services and, in particular, networks. Almost every link in the value chain sees IoT as a new source of revenue, and mobile network operators were among the first to seize upon this when they pushed early machine-to-machine (M2M) solutions in the early 2000s.
So are cellular networks going to completely fulfil the needs of low-cost, high-scale that IoT applications will demand as they grow?
Probably not, and hence, the massive IoT scale at the edge of the network (think of smart cities, smart buildings and autonomous vehicles) has provoked interest in other, low-capacity, low-power wireless network technologies. These include long-range networks such as LoRa and Sigfox, as well as short-range connectivity options such as Zigbee and Bluetooth LE (Smart) and, of course, Wi-Fi.
At this stage, it is difficult to constrain traffic levels for many IoT applications, so it is clear that other approaches will be necessary. Organisations, in both the private and public sectors, will need to think carefully about potential scaling issues in the networks they will need to use in IoT solutions. Range, capacity, reliability and price will all have an impact on the viability of any fully deployed IoT application.
This is where mesh networks have strong appeal. Here, the principle is that instead of constructing the network as a star or tree, radiating out to the edge with a ‘backhaul’ to a core, each node can relay traffic to another node – thus forming a mesh – as well as being used as an edge device itself.
The theory is that, unlike regular networks that become clogged as more devices are added, with mesh networks, adding more nodes makes the mesh better. This decentralized control approach makes the mesh feel more like a ‘community’ than a carrier.
Mesh networks have many advantages. They offer alternative paths for network traffic to route around ‘damage’ or bottlenecks. Traffic can be split and shared to improve performance. They enable ad hoc deployment and extension, without the need for central control to pre-build or pre-plan backhaul connectivity or infrastructure.
This means there is a lot of flexibility with a mesh architecture, so they have often been exploited where networks have to be rapidly deployed in difficult situations, such as in emergency or military scenarios.
Home and away
Many people will encounter a form of mesh networks via Wi-Fi in the home. Dual and multi-radio systems are often used to extend domestic networks, so that no wired connection is required between access points. These typically work very well, as they tend to involve relatively small numbers of access points in fixed locations. Once the mesh is established, it just carries on working. If access points need moving or adding, after a short reconfiguration, it all works again.
The premise of mesh networking is that this should scale up to work in other scenarios, such as smart cities, buildings and vehicles. But these represent a more complex and dynamic environment than that which is seen in a home network. The cooperation between meshing devices can be complex and grow out of proportion with network scale. Alternately, a central root device that coordinates the mesh introduces the problem of a single point of failure and loses the autonomy of the edge to adapt.
The problem only gets worse if the mesh has to dynamically configure itself, such as if the devices are physically mobile, which ironically is when the ability to build ad hoc networks really comes into its own. Many Wi-Fi and mesh solutions become unreliable and choked when overloaded by users, radio interference or their own traffic flow management. Current cities with masses of static, mobile and pop-up networked devices already stretch and break the scaling of traditional cellular networks. Mesh networks will need to exceed current capabilities by some margin in order to add value to the wireless edge.
A solution could be close at hand. One approach comes from Rajant Corporation, for example. Its BreadCrumb network devices were designed to give a ‘Hansel and Gretel’ safe pathway home in the most challenging environments. The highly adaptive mesh architecture this requires makes this type of technology suitable for large-scale and dynamic IoT use cases.
Just as many of the wireless technologies already enjoyed by businesses and consumers once originated in military developments, so too are the more robust wireless mesh technologies. Those looking to deploy large-scale, multi-purpose networks for IoT applications – in public spaces and smart environments, for example – should again be considering the potential for mesh. It has been assessed before (in networks in street furniture serving mobile users and so on), but now the criteria are more rigorous and mesh solutions have evolved.
Large-scale IoT mesh networks will need to be able to autonomously adapt to traffic needs and failures in a dynamic environment, where elements of the mesh itself will move around and shift in numbers. It is a complex real-time problem that needs to be robust and secure, as well as demonstrating sufficient capacity at a low deployment and operational cost. However, perhaps now the time is right for military and emergency-grade mesh technologies to play their part in the large-scale yet rigorous world of commercial IoT applications.