In essence, the IPSO Alliance describes smart objects as small computers at a cost of only a few dollars and with a minimal footprint.
This means that, with the provision of processors (8-, 16- or 32-bit microcontrollers), memory (several tens of kilobytes), storage, and so on, along with an inherent ability to sustain an IP connection (perhaps limited to sending/receiving a few hundred kilobits per second), almost anything and everything can become connected at an affordable cost.
These devices would typically be battery operated, although this is not an absolute requirement. As such, it is envisaged that these smart objects will be embedded in everyday products such as cars, light switches, and industrial machinery, enabling a myriad of applications for home and commercial automation, in factories, throughout industry, and even in healthcare situations.
The scalability and flexibility of IP are suitable for the diverse range and potential number of applications, and it is its well-established architecture, with existing applications for email, Voice over IP (VoIP), video streaming, and so on, that affords the protocol its robust and adaptable usage. The IP stack has been regarded as large and perhaps cumbersome, requiring high amounts of processing power and memory.
However, several lightweight revisions have emerged to accommodate smaller devices and lower energy footprints. Furthermore, the lightweight nature of the new generation IP stack has allowed itself to be used in conjunction with other protocols, such as low power Wi-Fi, ZigBee, and Bluetooth low energy. Since IP can run over almost anything, adapting the stack to run over ZigBee or Bluetooth low energy, for example, is a relatively straightforward task, as we highlight in Figure 6.3. As can be seen in the figure, a 6loWPAN adaptation layer is used cohesively to allow both ZigBee and Bluetooth low energy to coexist with the upper layers of the IP stack, namely IPv6 and User Datagram Protocol (UDP) /Transmission Control Protocol (TCP).