IoT was inspired by the member of RFID community who pioneered Radio Frequency Identification (RFID), used in barcode detectors for the supply-chain management domain that allowed accelerating the process of data transfer directly between devices with no human involvement. It is hard to find the IoT technological stack given the numerous technology solutions that surround it. But, for simplicity, we break down IoT technology stack into four layers:

Device hardware – Devices act as an interface between digital and real world. They are actually the things within “Internet of Things” (IoT). They consist of microcontrollers, sensors to sense the data, and actuators to perform specific actions.

Device software – The devices have functional software and in-built technologies for implementing communication with the cloud and performing real-time data analysis within the IoT network. This functional software makes the devices ‘smart’.

Communication – Data collected by the devices is sent to a common platform which provides a common language for devices to communicate with each other. Communication is an important part in building an IoT network. Various communication protocols include – 

1. Bluetooth: It is useful for short term and short distance data exchange. It is present in every smartphone and has sensors. IoT systems involve small devices and sensors, so Bluetooth low energy (BLE) is important in applications where power consumption is crucial.
2. Wi-Fi: It provides internet access. It supports IoT applications that require low latency and high bandwidth.
3. RFID: Wireless electromagnetic fields are used by RFID to identify sensors and objects. It is used to generate unique ID for the object and solves the identification issues. It is classified into active and passive RFID based on technique of power supply provision in Tags. Passive RFID uses the power of the reader’s interrogation signal to communicate ID to the RFID whereas in Active RFID, readers have their own battery supply and instantiate the communication. The main components of RFID are tag, access controller, reader, software, and antenna. It is secure, accurate, efficient, reliable and inexpensive and has a wide range of wireless applications like distribution, patient monitoring and tracing. For e.g. this technology is used to eliminate the delays on the road tolls by collecting tolls electronically. Payment is automatic and cars don’t need to stop. Also, RFID tags are used in prepaid transport passes to control entrance payment when travelling around the city.
4. Radio frequency (RF): It is the easiest form of communication. It consumes low energy and is relatively simple to configure.
5. Satellite: It enables cell phone communication through antenna. They have stable and universal connections. Advancement in communication satellites are making it possible to provide a large range for transmitting the data to the IoT platform or cloud. GPS is an example of satellite based navigation systems.
6. Near field communication (NFC): It uses conventional radio frequency identification methods that use electromagnetic induction and loop antennas to transmit data. It comes with encryption as low speed communication and is used for short-range data exchange. The data can be transferred within a specific range of 100 meters and to work in large range it needs its own power supply. For e.g. NFC works in contactless payment methods. In it, you just have to tap or hover the contact less credit or debit card on the RFID reader and the antenna catches the signal from the NFC tag and authorizes the payment.

Platform – Sensors in the devices sense their surroundings and send the data securely to IoT platforms for further analysis. IoT provides the platform for all devices to dump their data and provide common language to communicate with each other. Platforms can be either on-premise or cloud-based.