From a technical point of view, the Internet of Things is not the result of a single novel technology; instead, several complementary technical developments provide capabilities that taken together help to bridge the gap between the virtual and physical world.
These capabilities include:
a) Communication and Cooperation: Objects have the ability to relate with each other and with their surroundings via networks such as GSM and UMTS, Wi-Fi, Bluetooth, ZigBee, and those referring to Wireless Personal Area Networks (WPANs). There are several reasons why objects will need to communicate with each other. For example for security purposes, an object can request authentication from other remote or near devices before granting access to particular information or services.
b) Addressability/ Discoverability: Objects can be located and addressed via discovery, look-up, or name services, and can therefore be remotely accessed or configured.
c) Identification: Objects are uniquely identifiable. RFID, NFC (Near Field Communication), and optically readable bar codes are examples of technologies with which even passive objects which do not have built-in energy resources can be identified (with the aid of a “mediator” such as an RFID reader or mobile phone). Identification enables objects to be linked to information associated with the particular object and that can be retrieved from a server, provided the mediator is connected to the network.
d) Sensing: Objects collect information about their surroundings with sensors, record it, forward it, or react directly to it.
e) Actuation: Objects contain actuators to manipulate their environment (for example by converting electrical signals into mechanical movement). Such actuators can be used to remotely control real-world processes via the Internet.
f) Embedded Information Processing: Smart objects feature a processor or microcontroller, plus storage capacity. These resources can be used, for example, to process and interpret sensor information, or to give products a “memory” of how they have been used.
g) Localization: Smart things are aware of their physical location or can be located. GPS or the mobile phone network, are suitable technologies to achieve this, as well as ultrasound time measurements, UWB (Ultra-Wide Band), radio beacons (e.g. neighboring WLAN base stations or RFID readers with known coordinates), and optical technologies.
h) User Interfaces: Smart objects can communicate with people in an appropriate manner (either directly or indirectly, for example via a smartphone). Innovative interaction paradigms are relevant here, such as tangible user interfaces, flexible polymer-based displays, and voice, image, or gesture recognition methods.
Most specific applications only need a subset of these capabilities, particularly since implementing all of them is often expensive and requires significant technical effort. But these days wireless communications modules are becoming smaller and cheaper, IPv6 is increasingly being used, the capacity of flash memory chips is growing, the per-instruction energy requirements of processors continues to fall and mobile phones have built-in bar code recognition, NFC, and touch screens – and can take on the role of intermediaries between people, everyday items, and the Internet. All this contributes to the evolution of the Internet of Things paradigm: From the remote identification of objects and an Internet “with” things, we are moving towards a system where (more or less) smart objects actually communicate with users, Internet services, and even among each other. These new capabilities that things offer opens up fascinating prospects and interesting application possibilities, but they are also accompanied by substantial requirements relating to the underlying technology and infrastructure. In fact, the infrastructure for the Internet of Things must not only be efficient, scalable, reliable, secure, and trustworthy, but it must also conform with general social and political expectations, be widely applicable, and must take economic considerations into account.