The Internet of Things (IoT) paradigm enables interconnected among device anytime, anywhere on the planet—providing the Internet’s advantages in all aspects of daily life. Analysts predict that the IoT will comprise up to 26 billion interconnected devices by 2020.
The conventional Internet has proved valuable in almost all endeavors by giving people the ability to interact with global information and services. The majority of this interaction happens through the World Wide Web, with client computers running a browser and communicating with cloud-based servers. However, the Internet is not limited to the Web: a wide diversity of other protocols are employed to make use of global Internet connectivity.
The IoT is considered to be the next logical evolution, providing extensive services in manufacturing, smart grids, security, healthcare, automotive engineering, education, and consumer electronics. Many of these systems already have a Web presence but use protocols that are largely Web independent.
Practical issues with the IoT vision must be addressed, including how to handle dramatic increases in network scale and how to determine device proximity, sometimes referred to as localized scalability.
In an IoT world, preferentially discovering things nearby and letting users interact with them is a powerful mechanism for overcoming a global network’s scale and complexity. Other important IoT enablers are peer-to-peer connections, low-latency real-time interaction, and integration of devices that have little or no processing capability.
THE IOT VISION
The Web provides an important interaction model for the IoT by letting users get device-related information and in some cases control their devices through the ubiquitous Web browser. The conventional Web is a convenience we enjoy as we search for information, respond to email, shop, and engage in social networking; the IoT would expand these capabilities to include interactions with a wide spectrum of appliances and electronic devices that are already ubiquitous in the early 21st century.
We refer to devices that are part of the IoT and directly accessed, monitored, or controlled by Web technologies as the Physical Web: Physical Web = Web technology + IoT. Identifiers are the key to enabling any kind of interaction among devices. From an IoT perspective, IPv6’s 128-bit addresses serve as identifiers for a global network of devices.
Alternatively, Uniform Resource Identifiers (URIs), which include both locators and names, provide a higher level concept that bridges those devices to existing Web technology. The Uniform Resource Locator (URL) is used in conjunction with a Distributed Name Service (DNS) to route and connect to services. Uniform Resource Names (URNs), such as globally unique IDs, are resolved by scheme-specific methods.
A distinguishing aspect of the Physical Web is to consider URIs as the primary identified Many researchers and practitioners in this field, including the authors of this article, expand the IoT definition to include enabling an Internet presence for any person, place, or thing on the planet, thereby pushing our notion of the Physical Web beyond smart devices.
Clearly, an Internet presence cannot occur without processing and networking, so instead of providing them directly, an Internet service can provide information and perform actions via other nearby devices serving as a gateway to that proxy service.
Gateway devices will enable billions of people, places, and things to participate in the IoT—most people today already carry one. The smartphone, the most popular computing device of all time, with more than 1 billion users, is well equipped to serve as this pervasive portal. Figure shows the two distinct interaction modes that smartphones can enable in the IoT. Through direct interaction, a smartphone can query the state of an IoT device in its proximity and then provide a bridge between low level peer-to-peer protocols, such as Bluetooth or Wi-Fi, and Internet protocols, such as HTTP and TCP.
One example is the fitness monitor, which uploads a user’s step count through his or her phone over a 4G network to the user’s account in the cloud. Through proxy interaction, mobile users who happen to be near an IoT-enabled object or device can look up associated information published by interested parties through a Web service using their smartphone, just as they would when performing a Web search. One example is a movie poster that enables nearby people to automatically access a webpage on their smartphone and buy electronic tickets online.