The traditional use of the internet for communication has been extended to almost everything other than computers and mobile devices. As noticed recently, almost every object can be enhanced to communicate with other objects (machine-to-machine) or with human beings (machine-to-human), and to effectively generate large amount of data for decision making.
This evolution that extends internet to everything has given birth to a novel field of research known as Internet of Things. The term was first mentioned by British technology pioneer, Kevin Ashton in 1999. It is estimated that the about 30 billion devices would be connected using IoT architecture the year 2020. Also according to Forbes (2017), the global IoT market will grow from 157 billion (US Dollars) in 2016 to 457 billion (US Dollars) by 2020, thereby achieving a Compound Annual Growth Rate (CAGR) of 28.5%. The projection also stated that industry spending in IoT by 2020 would average 40 billion (US Dollars) for areas like transportation and logistics, discrete manufacturing, and utilities. The projection for health and life sciences would be an increase in IoT spending from 520 billion (US Dollars) to
1.33Trillion (US Dollars). These forecasts are an indication that companies expect a huge Return on Investment (RoI) on their IoT products and services. These projections are realistic as evidenced by numerous IoT products available in the market today with a huge impact in both domestic and industrial applications. According to Luigi A., et al. (2010), IoT offers great potentials for development of an enormous products and solutions.
It is important to consider the definition of IoT to provide a better understanding of the concept. Though the definition of IoT is still ambiguous as there is yet to be a concrete definition for the term, the author in this work provides a definition in terms of “Internet” and
“Things”. The “Internet” is a network of protocols upon which computer communication thrives, while Things on the other hand are physical object that connects to form part of network infrastructure. A thing in this case could be a washing machine, gas burner, refrigerator, air conditioner etc. that has been made smart with wireless sensors, actuators, and Radio Frequency Identification (RFID) embedded in them to enable them connect to the internet for communication. The International Telecommunications Union (ITU, 2012) defines IoT as a global infrastructure for the information society, enabling advanced services by interconnecting (physical and virtual) things based on existing and evolving, interoperable information and communication technologies. From the foregoing, Internet of Things can be defined as the network of heterogeneous physical objects that have been embedded with sensors, actuators, software, and RFIDs to provide them with connectivity to communicate.
This interconnectivity these objects and services creates various IoT products (Miorandi, 2012).
i. Application Areas of Internet of Things
The ability to equip objects with intelligence for communication has created tremendous impact in various facets of human endeavor. IoT has led to an upsurge of ICT based job and innovation (Miorandi, 2012) which has given birth to many products and services used both in industries and homes. It is important as part of the review on IoT to discuss some of its
application areas, and how lives and societies are being transformed. Here, the discussion is of the areas of application is limited to health, transportation and logistics, smart city, and home automation. The diagram below provides a brief description of the application areas of Internet of Things.
Source: Adapted from Gubbi, (2013).
Figure: 6 Internets of Things Application Areas
ii. Internet of Things Research Challenges
Despite the wide acceptability and application of IoT, the field still contends with numerous challenges majorly as a result of the homogeneity of the devices and sensors that connect to create a network. These challenges have thrown open new areas of research. In this section, a review of two of these challenges and efforts made to address them are considered.
iii. Privacy and Security
Privacy and security of data over an IoT is of paramount concern and a lot is being done to address this. As mentioned earlier, the complex nature of IoT network is as a result of the heterogeneity of the various devices which mostly are vulnerable to attacks (Atzori, et al., 2010; Gubbi, et al., 2013). These attacks come in different ways - disabling of network like denial of service, mutilation of data packets, and intrusion to access private data (Gubbi, et al., 2013). This vulnerability is as a result of the wireless medium for communication, and low computing power of the IoT devices (Atzori, et al., 2010).
With reference to the work by Gubbi, et al., (2013), there are three physical elements of IoT that are greatly prone to privacy and security attacks – Wireless Sensor Networks (WSN), cloud, and Radio-Frequency Identification (RFID). The authors opined that RFID is the most prone to attacks due to its porosity which allows alteration of data packets along network routes (Atzori, L., et al., 2010), thereby raising concerns about the safety private or personal information (Mashal, et al., 2015). Two main problems were identified with RFID; RFID reader collision which is as a result of signal overlay, and RFID tag collision which occurs as a result of overcrowding of tags in a limited area. WSN on its part cannot be authenticated as it is not considered a node on an IoT network (Atzori, et al., 2010).
Bandyopadhyay and Sen (2011) and (Whitmore, et al. (2014), stressed the need for greater effort to address this issue and suggested a reliable security model and standards that would recognize the various users and objects on an IoT network. Another possibility would be to develop an algorithm for data encryption and authentication for the IoT network.
iv. Common Architecture Framework
The homogenous nature of IoT devices makes it difficult to define a common architecture that would address the issue of interoperability - communication and service. The architectural deficiencies noted so far are; scalability, portability, communications, deployment, control, interoperability, and connectivity which require an architectural reference model to be developed for IoT.
Gubbi, et al. (2013), proposed an architecture that is centered on computing though, acknowledged it may not be the most appropriate for IoT. In the work, Research Directions for The Internet of Things, Stankovic, (2014), suggested that the elements enhancing IoT network such as sensors and actuators have their separate architectures defined for them.
Nonetheless, this approach was noted to have its own limitations as a result demand for usage of common utilities by the devices which could result in interference. Other researchers like the European FP7 Research Project IoT- A project partners in the work, Introduction to the Architectural Reference Model for the Internet of Things developed an Architectural Reference Model (ARM) to address the problem of having a shared architecture for devices on an IoT network. Conclusively, to achieve the desire of having a shared architecture for IoT network is still far ahead and entails huge research collaboration from all industry players to be realized.