Internet of Things

3Interoperability

3.1 Applications in the IoT

Costs, limited size and minimal energy consumption are a few of the reasons that IoT devices have limited computational capabilities. Because of these functional and economic requirements, smart objects, especially those that are battery‐powered, cannot afford to have heavy processing loads and use expensive communication protocols. On the one hand, limited processing capabilities means that it is hard to process large messages. On the other hand, less processing means lower energy consumption. As a result, IoT devices typically need to minimize the amount of transmitted data.

Devices that operate in low‐power and lossy networks (LLNs), can greatly benefit from lightweight protocols. Large messages result in more fragments (6LoWPAN), which introduce overhead: due to the unstable nature of LLNs, transmitting more fragments can require multiple retransmissions before a whole message can be successfully reconstructed by the receiver. These retransmissions may result in more delay and energy consumption.

Communication protocols are specific communication paradigms, which can be classified into two categories: request/response and publish/subscribe (pub/sub). Specific application scenarios have requirements that drive the choice of the most suitable communication paradigm (and protocol). The question of which architecture fits best does not have a clear “one‐for‐all” answer.

3.2 The Verticals: Cloud‐based Solutions

The early days of the ...