A smart device is an electronic device, generally connected to other devices or networks via different wireless protocols (such as Bluetooth, Zigbee, near-field communication, Wi-Fi, NearLink, Li-Fi, or 5G) that can operate to some extent interactively and autonomously. Several notable types of smart devices are smartphones, smart speakers, smart cars, smart cards, smart thermostats, smart doorbells, smart locks, smart refrigerators, phablets and tablets, smartwatches, smart bands, smart keychains, smart glasses, smart TV, and many others. The term can also refer to a device that exhibits some properties of ubiquitous computing, including—although not necessarily—machine learning.

Smart devices can be designed to support a variety of form factors, a range of properties pertaining to ubiquitous computing and to be used in three main system environments: physical world, human-centered environments, and distributed computing environments. Smart homes indicate the presence of sensors and some detection devices, appliances, and a database to control them.

Form factors

In 1991, Mark Weiser proposed three basic forms for ubiquitous system devices: tabs, pads and boards.

  • Tabs: accompanied or wearable centimetre sized devices, e.g., smartphones, smart cards
  • Pads: hand-held decimetre-sized devices, e.g., laptops
  • Boards: meter sized interactive display devices, e.g., horizontal surface computers and vertical SMART boards.

These three forms proposed by Weiser are characterized by being macro-sized, having a planar form and by incorporating visual output displays. These were also envisioned more as information appliances. If each of these three characteristics is relaxed, this range can be expanded into a much more diverse and potentially more useful range of ubiquitous computing devices.

Characteristics

Smart devices are typically composed of a hardware layer (including a radio that transmits signals), a network layer (through which devices communicate with each other), and an application layer (through which end users deliver commands). These layers often include the following characteristics:

  • A set of system hardware & software IT resources. This set is usually static, fixed at design time.
  • Dynamic component-oriented resource extensions & plug-ins (plug and play) of some hardware resources.
  • Remote external service access and execution.
  • Local, internal autonomous service execution.
  • Access to specific external environments: human interaction, physical world interaction and distributed ICT / virtual computing interaction.
  • Some ubiquitous computing properties.

Common types of smart devices include:

  • Tab and pad type smart devices that often act as personalized smart mobile devices
  • Smart environment devices.

Ubiquitous computing properties

Weiser's vision for ubiquitous computing can be summarized in terms of two core properties:

  • Devices need to be networked, distributed and transparently accessible.
  • Human–computer interaction with devices is hidden to a degree from its users.

It is proposed that there are two additional core types of properties for ubiquitous computing systems: