Many people have tried to define the Internet of Things. But we all know the essential element: To build interconnected products. IoT systems are not complicated, but designing and building them can be a complex task. And we already have all the tools we need today to start making the IoT a reality. Your first step in building an IoT device is to figure out how it will communicate with the rest of the world. Your choice of communication technology directly affects your device’s hardware requirements and costs. So which networking technology is the best choice? Let’s take a factory as a typical case for an IoT system. A factory would need a large number of connected sensors and actuators scattered over a wide area. A wireless technology would be the best fit. This is a wireless sensor network. Data from each sensor passes through the network node-to-node. The nodes in a wireless sensor network are low-cost devices, so they can be deployed in high volume. They also operate at low power so that they can run on battery, or even use technologies such as energy harvesting. An edge node acts as a gateway between the wireless sensor network and the Internet. It can also perform local processing, provide local storage, and can have a user interface. The battle over the preferred networking protocol is far from over. And there are multiple candidates. The first obvious networking candidate for an IoT device is Wi-Fi, because it’s everywhere. Certainly, Wi-Fi can be a good solution for many applications. Almost every house that has an Internet connection has a Wi-Fi router. However, Wi-Fi needs a fair amount of power. There are a lot of devices that can’t afford that level of power. For example: sensors located in places that are difficult to power from the grid. But there are newer networking technologies that allow for the development of low-cost, low-power solutions. These technologies support the creation of very large networks of very small, intelligent devices. Some of the R&D; efforts to build these kinds of low-power networks include: Low-power radios that allow several years of battery life; energy harvesting as a power source; mesh networking for operation without human intervention; and new application protocols that allow devices to work autonomously. One of the major pieces of low-power wireless is the IEEE 802.15.4 radio standard. It was released in 2003. Radios that meet this standard provide the basis for low-power wireless systems. Power consumption of commercial RF devices is now cut in half compared to only a few years ago. And we are expecting another 50% reduction with the next generation of devices. Devices must also perform their tasks in the shortest time possible to save energy. This means that their transmitted messages must be as small as possible. So this has implications for protocol design. And it is one of the reasons why 6LoWPAN has been adopted by companies such as ARM and Cisco. 6LoWPAN provides encapsulation and header compression mechanisms that allow for briefer transmission times. At Micrium, we believe that any protocol that carries IP packets has an advantage over all others. The requirements for IoT devices are so diverse that a single technology just can’t meet all the requirements for range, power, size and cost. But we believe that 6LoWPAN will be the choice for wireless sensor networks and for other IoT systems that need IP-based protocols. If your IoT network is local and machine-to-machine, then the wireless protocols we’ve discussed are good candidates. But if your goal is to remotely control devices or otherwise transmit data over the Internet, you’ll need IPv6. If at all possible, it’s crucial that your IoT networks all make use of the suite of Internet protocols. That’s UDP, TCP, SSL, HTTP, and so on. And your networks must support IPv6. Why? Because the current IPv4 standard faces a global addressing shortage, as well as limited support for multicast, and poor global mobility. IPv6 provides more addresses than there are grains of sand on Earth. Or to put it another way, that a million trillion trillion addresses per person. With IPv6, it is much simpler for an IoT device to obtain a global IP address, which enables efficient peer-to-peer communication. The importance of IP to the Internet of Things doesn’t automatically mean that non-IP networks are useless. It just means that non-IP networks will require a gateway to reach the Internet.

• published: 12 Jan 2015
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