Decades of Internet of Things towards 21 st Century: A Research-Based Introspective

: Internet connects people to people, people to machine, and machine to machine for a life of serendipity through a Cloud. Internet of Things networks objects or people and integrates them with software to collect and exchange data. The Internet of things (IoT) influences our lives based on how we ruminate, respond, and anticipate. IoT 2020 heralds from the fringes to the data ecosystem and panaches a comfort zone. IoT is overwhelmingly embraced by businessmen and consumers due to increased productivity and convenience. Internet of Things facilitates intelligent device control with cloud vendors like Amazon and Google using artificial intelligence for data analytics, and with digital assistants like Alexa and Siri providing a voice user interface. Smart IoT is all about duplex connecting, processing, and implementing. Centralized IoT architecture is vulnerable to cyber-attacks. With Block Chain, it is possible to maintain transparency and security of the transaction's data. Standardization of IoT devices is achievable with limited vendors based on Platform, Connectivity, and Application. Robotic Process Automation (RPA) using bots has automated laborious tasks in 2019. Embedded Internet using Facial Recognition could reduce the pandemic crisis. Security concerns are addressed with micro-segmentation approaches. IoT, an incredible vision of the future makes systems adaptive with customized features, responsive with increased efficiency, and procurable with optimized cost. This paper delivers a comprehensive insight into the technical perspectives of IoT, focusing on interoperability, flexibility, scalability, mobility, security, transparency, standardization, and low energy. A smart classroom is implemented based on the concepts of IoT.


INTRODUCTION
Service-Oriented Architecture (SOA) Design: This design faces scalability, processing, and data transfer issues. Powerful service description language, service discovery [219] methods are yet to be catered to the needs. [282].
Signal processing: Identifies and collects the required data and processes it suitable for a particular application.
Software-Defined Network (SDN): Controls Network and nodes dynamically based on programming. SDN combined with a deterministic virtual network (DVN) and lightweight encryption facilitates ultra-low latencies and improved security suitable for Industrial IoT. [269] Standardization: Yet there is no existing standardization [NIST] in connecting disparate networks [11]. IEEE has produced more than 80 standards relating to IoT. [223]. In 2013, universities and industries collaborated [135] and developed an architectural reference model for IoT referred to as IoT-A, which is no longer active. IEEE standardization is required to preserve data flow across heterogeneous networks (HetNet) and provide design specifications for information exchange and processing. In smart home automation, different devices are from different vendors. IoT faces connectivity issues. [240] Traffic Threats: IoT device ports decide on the network traffic. These ports are susceptible to threats. [110] Uncontrolled Environment: One model will not fit for all. Getting accurate and stabilized results for IoT in an uncontrolled environment is the challenge. [153.].
Unified Information Infrastructure: Different devices occupy different bandwidths. A unified information infrastructure suitable for heterogeneous devices is required.
Unique ID: Due to limited IPv4 addresses, it was impossible to consign each device with a unique identifier. This is overcome using IPv6. Network plays a major role in IoT. IPv6 routing protocol (RPL) is used for resource-constrained low power lossy network (LLN). This improves network lifetime, throughput and QoS. Internet Protocol (IP) manages traffic load from multiple devices and provides seamless connectivity [217]. RPL is used for real-time applications to transmit sensitive data. [30]. It replaces an up-to-date route in case of dynamic network changes.
Virtualization: Lot of challenges exist in realizing, developing, and adopting a model to the existing scenario to meet the requirements. [121] Web Interface: 60% of the devices raised concerns about insecure web interfacing such as cross-scripting and weak session management.
Compatibility: 5G is revolutionizing IoT with faster data rate [245] for future IoT applications such as virtual reality, high definition video streaming, and augmented reality with 25 Mbps for optimized performance. 5G is in its budding stage and requires scalability, low-latency for video games, upgraded handover efficiency, increased battery life-time, time constraints for real-time applications and smart service provider to provide services as per application and mobility. [122]. Radio Access Technology (RAT) and antenna innovations serve the purpose. Modulation is implemented in the physical layer. Timely handling of multiple input data will produce errors. These issues need to be handled. Mutual shaping between 5G and IoT will improve business models. [183].

CATEGORIES OF IoT:
Internet IoT is an embedded internet technology encompassing the physical and digital components. IoT depends on its applications: Consumer IoT (C-IoT) for smart home automation [184] proliferates the quality of people's life with saving in time and money. Smart Homes are automated buildings with electronics, sensors, and software networked together to reduce energy wastage in devices and improve safety. [200]. Researchers analyze the revenue patterns targeted by the manufacturing companies. [87]. Smart Homes use Arduino as cyber physical systems for energy monitoring. [167] (ii) Commercial IoT: Healthcare Automation and Transport Automation for Vehicle to Vehicle Communication. In-home care, IoT devices such as wearable sensors are fused with IoT services such as telemedicine. [296].With increasing chronic diseases, Clinic centric is focused on Patientcentric using a multi-layer e-Health Architecture. [29]. Information and communication technologies (ICT) provide promising e-Health solutions. [152]. Ting et.al. developed an anti-counterfeit platform to check the creditability in online purchases. [170].
Industrial IoT (IIoT): integrates operational and informational technologies to design autonomic industrial plants, smart agriculture etc., [165]. With IIoT, [257] for intelligent transportation, a vehicle and its movement can be monitored. Based on the predictions, traffic can be anticipated resulting in shortest route discovery and time-saving. [176] (iv) Infrastructure IoT: connects smart cities with sensors and user-friendly apps. Big data is used to provide smart transportation, smart healthcare etc., in cities. [124] .
Fiware is an open platform for smart cities. [85].
Military IoT: Robots are used for surveillance in disaster-prone areas.

IoT Communication Technologies:
Design related to the applications of IoT include connectivity, cost, coverage, deployment, infrastructure, lifetime, mobility, modality, QoS, size and topology for cellular and non-cellular technologies [77]. Some of them are: (i) RFID, Sensor: Radio Frequency Identification has a tag and a reader [Agrawal et.al.]. This uses the radiofrequency electromagnetic field to transfer data associated with the object. Each RFID [298] has a unique ID applied to the project. It has a microchip along with an antenna as a package. RFID Tags could be self -powered active tags or signal powered passive tags. They monitor objects in real-time without Line-of-Sight. Passive RFID tags are made duplex to remotely exchange data for communication. [

IoT Architecture and it's Operating Systems :
IoT is conceptualized to reality by jumbling up different technologies. IoT Vision is to interconnect heterogeneous devices Anywhere, Anytime and with Any-media using IP, communicate and process data using Cloud and embedded software. [22]. For example: To analyze multimedia traffic, media-aware traffic architecture is proposed for IoT. IoT is an interdisciplinary field that is oriented towards three prototypes: Things oriented (devices), Internet-oriented (middleware), and Semantic oriented (knowledge) [107] e.g., WoT. IoT expands human-human communication to human-things and things-things to exchange information between the physical world and the virtual world [124]. Architecture can be user-centric or cloud-centric. In user-centric, the user will be at the center and uses data and infrastructure depending on the applications. Economically cloud-centric is better. Al-Fuqaha et.al. envisioned IoT as a technology that enables physical objects to see, hear, think, share information, coordinate decisions, and perform jobs.
IoT requires a power-optimized communication stack, reliable peer-to-peer communication stack, and an Internet empowered communication stack. [184]. IoT architecture facilitates a systematic understanding of the tools, technologies, and methodologies vital for a developer to connect the digital world and the physical world [72] and build the infrastructure. IoT Architecture is framed based on the application such as healthcare and its pre-requisites such as security. [228]. Currently RFID and healthcare are rated stringent. Data is created by the device. Data is sent to the centralized service using HTTP/CoAP/MQTT. HTTP is not suitable for low bandwidth applications. MQTT -A Resource-constrained protocol uses publish /subscribe model. It has low overhead, lower bandwidth, but has no encryption procedures. [211].CoAP is suitable for low power and low bandwidth applications. A centralized server is risky in case of data loss without back-up. IoT architecture should satisfy scalability, interoperability, reliability, and Quality of Service. IoT requires real-time analytics, a platform to analyze the aggregated data, a cloud to collect the data, trigger remote action and send remote notifications. IoT enabling technologies in tandem comprises of the hardware, middleware, and Application occupying the perceptive, network, and application layers respectively. The basic architecture of IoT is a three-layer architecture [124,157,290,215]. It consists of the physical layer, network layer, and the application layer as shown in Figure.3. A clarified insight into the lifecycle of the processes involved in IoT leads to prediction in future developments.

IoT things (The Physical Layer):
This is the physical layer that senses and gathers entities from the environment. [303]. This specifies the path between adjacent nodes for data transfer. Hardware consists of wireless sensors, Robotic cameras, Radio Frequency Identification Tags (RFID) etc., based on the application. Barcode facilitates automatic identification of anything. Wireless Sensor Networks [122] are cost-efficient and power-efficient. Physical devices and controllers referred to as 'Things' collect and transmit the data on receiving the command.
Sensors collect data and share it with the centralized system for analytics. Sensors have transceivers, processing units, A/D converters, and recently they operate on one frequency range, making it less complex. Actuators control the things using the electrical inputs. Simply put, for the smart room controller, a temperature sensor senses the heat, and sends the signal to the control center. The control center sends commands to the sprinkler. The sprinkler turns on and puts out the flame.
Sensorpedia is a new integration platform that guides users regarding identifying and sharing of sensor data. Sensor data is processed on a Google map. Users can search and explore published sensor data using an interface. [104]. In some cases data would be time-sensitive. In other cases, this data velocity creates an avalanche. For data that entails profound processing, it is sent to the cloud. Short- wave technologies like Bluetooth permits devices to communicate with each other. IPv6 connects sensors to the internet without additional processing.
Technologies used in the physical layer are Bluetooth, Wi-Fi (devices are connected by radio), BLE (short distances), 6LoWPAN (IPV6 and low power personal wireless personal area network) suitable for IoT, 5G improves data rate and latency. [224]. BLE uses Bluevoice for providing Speech Streaming Services. [98]. (ii) IoT Network Layer: This connects devices and servers and specifies the communication path over the network (IP Address). Data collected from the sensors are processed and analyzed intelligently for optimized decision making. Raw data collected from the sensors is converted into digital streams by Data Acquisition systems. Data acquisition samples the real-time physical entities and converts it into digital streams suitable for transmission using analog-to-digital conversion. The Internet gateway aggregates these digitized data and routes it to Wi-Fi or wired LAN for further processing. This layer inclusive of switches and routers is responsible for secured, reliable, timely delivery of data. Data is stored and retrieved as per queries.

(a) Challenges involved in Data Analytics and Processing:
Data analysis varies depending on the volume, velocity at which the data is generated, and the structure of the data. Data analysis is done using Machine Learning by fitting the data into the model. Based on the pattern generated from Machine Learning, a predictive analysis (of what would happen), prescriptive analysis (steps to be followed next), and adaptive analysis (to be in line with the changes) could be done. IoT includes real-time streaming data without delay using a real-time framework such as Apache Storm. If the size of the data is huge then distributed data analytics is used to reduce the load on a single server such as Apache Hadoop Server. Data is distributed across several nodes and is processed using the MapReduce engine. Apart from Data Processing, storing a huge amount of data is not feasible using the traditional database approach. IBM Cloudant provides a solution. Amazon, Microsoft, Google provide infrastructure, platform, and software as a service. Consumers save a lot of money and manpower. Based on consumption, charges are applicable. (iii)

IoT Cloud and Application Layer:
This provides application-specific services to the user. This specifies the interfaces and protocols used by IoT devices. [40].Once the data is aggregated, the information is either stored locally or in a centralized remote server to be analyzed. Then it is fed to new applications and services. IoT requires platforms, tools, and libraries to visualize the data. IBM's BlueMix is a platform that connects innumerable devices and sensors and provides API's for data visualization in formats specific to the device. [266].ThingSpeak supports sensor data along with MATLAB for visualization. Individual software work as per requirements on device control, visualization, and analytics. Data and conclusions are shared with other applications leading to an innovative IoT.

(a) IoT and Cloud Integration involves:
Device Management: As devices increase, management [230] such as registration, updating of software complexity, and cost increases. With Cloud, based on usage, charges apply. Resource Pooling: Based on demand, resources are integrated into the Cloud [108]. Data Storage: Large scale data and Long term data is stored in the Cloud. Digital Twin: In case of failure, there will be a back-up and that will be used. Access Control: There is access control authentication for Cloud.
IoT employs protocols, networks, and applications. [236]. IoT applications are based on monitoring, control, automation, and optimization. [101]. Commonly used operating systems to enable the functionalities of the application domain are TinyOS [164], LiteOS, Contiki etc., They require few KBytes of RAM and provide optimized low power Internet Communication. Software Development Kits (SDK) supports application programming using C, C++, Java etc., Software connects IoT objects to the network using communication protocols. Table 1. Displays the functionality and the types of devices associated with each layer.

Middle-Ware Layer:
A middleware is a software that interconnects and manages these heterogeneous components [285] Smart Things is a Samsung cloud-based platform, which supports 300 plus devices for user control home automation. Web-of-Things and cloud is used as an interoperable platform for smart home. [24].This layer is between the application and technology layer to aid design workflow [147], data management [2], and interoperability. [57]. Data Management combines multiple databases and unifies interfaces. [33]. Centralized storage archives data and also integrates both structured and non-structured data. [92] HTML5, Web Socket, Canvas supports real-time applications. HTML5 and Adobe Flash are preferred for low latency. [304].Middleware manages the services offered by things, stores it, processes it, and analyses the data. [172]. Middleware is specific to the application. [198]. For example, ASPIRE is specific for RFID. There is no generic middleware common for smart home, smart transport etc., Middleware delivers application layer interfaces (API) for physical layer communication and related services to the applications. [31].IoT-ICN architecture is included in the middle layer. Real-world deployment is yet to be implemented. Wang et.al proposed a data platform (RESTful Web Service) as a middleware to access physical objects with a unique URI.
(v) Business Layer provides business models and graphs along with the data. fig.2 has proposed a seven-layer reference model based on the functionality:

CISCO [Cisco] as shown in
The physical layer has things ranging from a small chip to a big machine. These devices convert the data from analog to digital and are being controlled by the net. The Connectivity (Network) layer connects the IP -Enabled devices. If they are not IP Enabled, they are connected via gateways. This layer associates the necessary switches, routers, and protocols required for connectivity. Security is associated with this layer. The Edge Computing (Fog) layer translates the data into a form that is suitable for storage. [39]. Fog Computing bridges the gap between data centers and IoT devices. [13]. It is considered as a mini cloud close to the IoT devices. [273] .For example. The sensor provides several samples per second in a day. The Data Accumulation Layer keeps the data. Certain applications cannot run the data at network speed. This layer has data filters and converts data into relational tables. The Data Abstraction Layer collects data from multiple sources and reconciles differences in terms of format etc., Information interpretation occurs in the Application Layer. This gives data at the right time for real-time applications. Collaboration and processes layer involves collaboration for business logic to meet people and people use applications as per requirement. Security is involved in each of the layers. Devices have an IPAddress and communicate with the services offered by the Cloud. Devices without an IPAddress use short-range communication protocol such as ZigBee [48] and connect with an IoT Gateway which communicates with the services offered by the cloud. In future, there is a likelihood that the number of base stations will upsurge than the number of mobile phones. [145]. Figure 4 and Figure 5 relates the layers in the IoT architecture with their associated security.

Fig.4 IoT Reference Model Fig.5.IoT Security
Operating system [212] design features include low memory requirements, low cost, low power consumption, small size, low processing power, heterogeneity, catering to multiple network stacks, security, and energyefficiency. OS is usually embedded. It collects and communicates data over the Internet. TinyOS is used for low power wireless devices with commands and tasks for inter-component communication and tasks for intra-component communication. Contiki OS [4] is an open-source lightweight portable OS with low power, low memory, low processing, and low bandwidth. RIOT OS is the Linux of IoT. [27].This uses minimal resource devices and provides real-time services. Ubuntu OS is suitable for IoT devices. [275].Instead of the conventional programming languages, IoT uses scripting languages like Bash Shell in platforms such as GNU/Linux. [112].

Taxonomy for IoT Security Framework:
The Interagency International Cyber Security Standardization Working Group has formed the IoT task group in 2017 to formulate the cybersecurity standards [53] for IoT. [118] LTE is preferred for better bandwidth, and spectral efficiency but IoT architecture suffers from threats. [116].Salman et.al. reviewed on the existing standards and protocols for IoT. Common attacks in IoT include DoS attack, Man-in-the-Middle Attack. IoT security demands research on the privacy of data [218,259,128], prevention of loss of data from personalized devices, leading to impersonation attacks and prevention of malware via botnets which leads to Distributed Denial of Service Attacks (DDoS) [51]. For IoT devices to be secured, it requires to ensure authentication, integrity, confidentiality, availability, authorization, secrecy, and non-repudiation [IoT device]. To ensure these, cryptographic techniques [249] such as encryption at the wearable device level (AES and SHA algorithm), device level (Public Key Exchange (PKE)), network-level are implemented in an IoT Ecosystem. For a wider area of coverage and data stored in a Cloud, Internet Protocol Security (IPSec) and Secure Socket Layer (SSL)) are used. Symmetric (AES) algorithms, Asymmetric algorithms (RSA), Light Weight Algorithms, and Digital Signatures are used in IPSec for authentication. [260].IoT Botnets are massively attacked and controlled by Hackers. [19]. For instance Mirai cyberattack tool used brute force attack [194] and took over numerous IoT devices. This remains a mystery. Botnets IoT Security is based on the Application domain, Architectural Domain, Data domain, and Communication Channel.
In the physical layer, the sensor nodes operate with stringent power and memory requirements. This makes frequency hopping spread spectrum and public-key encryption hard to realize. Sensors could be compromised by transmitters and antennas from a distance. [Mahmud et.al.] RFID Tags suffer due to security issues in wireless technologies [28]. This requires mutual authentication implementation in high frequency RFID tags. [206]. A lightweight security algorithm with low power and area is achievable by using a combination of encryption algorithms. [205]. Network Layer is prone to man-in-the-middle attacks. Authentication prevents unauthorized access. Data sharing at the application layer poses threats to access control and privacy, resulting in disclosure of data. The application layer across heterogeneous networks demands user privacy and authentication. Physical layer security (PLS) is used to avoid data leakage. Challenge is to provide reliable security with low power. Modulation techniques decide upon the data rate, bandwidth, spectral efficiency, and power of the hardware used. PLS also depends on modulation in wireless technologies. If data is less, narrowband is used. If the data is more, then wideband communication is used. With bulky directional antennas secrecy is improved. By performing modulation after encryption, low power consumption and reduced hardware complexity is achieved. [222]. Narrowband IoT supports features like deep coverage both indoors and outdoors, less complex multiple devices, and low power consumption. With low power, Security is compromised. [77].5G supports narrow-band IoT and increasing traffic. [9].

Architecture
IPv6 communication protocol is used for IoT in the physical layer. Datagram Transport Layer Security Protocol (DTLS) is used in the network layer. Constrained Application Protocol (CoAP) is used in the Application layer and IPv6 is used for addressing in the proposed lightweight security architecture [232]. A comparison of the protocols used in the conventional and IoT security framework is detailed in Table.2.

Layers
Conventional IoT Physical Wireless-fidelity IPv6 Network TCP DTLS Application HTTP COAP IoT Security framework depends on time constraints, power and energy consumption, lightweight constraints, reliability, robustness, and smart applicability. [284]

Low Energy Methodologies:
Energy Efficiency is required for battery constrained IoT Devices. Zeeshan et.al. has provided energyoptimized solutions for wireless technologies operating with IoT. Towards 2025, IoT devices will reach 11 trillion [ISO/IEC], almost every device will have an internet node, and devices need to sustain energy. Green IoT is proposed for energy conservation. [52] Energy consumed by the sensor nodes is reduced by (i) Variable Duty Cycle: The duty cycle is varied, based on the ON time and OFF time of the node. This is made automatically adjustable. (ii) Multilayer based approach: Nodes are grouped as layers. Applying optimization techniques to these layers, power is reduced.
Low power Protocols for sensor networks: Vakulya et.al. proposed two protocols queue response protocol and piggybacking protocol for low power. This is achieved with an increase in latency. (iv) Frame size control: Based on the MAC frame size, optimization is achieved.
Low latency: IoT deals with real-time data applications where continuous data stream is required with low latency. This is achieved using parameter tuning with frame synchronization and sleeping behavior. (vi) Priority-based: By assigning pre-defined priority smartly to the nodes, nodes with the highest priority can access the media. This saves power.

(vii)
Variable back-off: By varying Back-off exponent (BE) and Contention Window Length (CW) of MAC, throughput, packet delivery ratio, and low energy is achieved. (viii) Self -configuration: Networks are configured with less overhead.

Standardization of IoT:
Smart objects consume and process large volumes of data that need to be transferred securely. This requires universally accepted standardization of protocols for interoperability between devices and applications. Bluetooth Low Energy (BLE)-Single mode has one protocol and provides low energy. [37].BLE Dualmode has low power and uses Gaussian Frequency shift keying for range extension. [42]. For power optimization, low baud rate, less channel usage, FHSS mode is used. Bluetooth 5.0 [229] has inherent range, data rate extensions, advertising extension features [66]. Its broadcasting message ability makes it suitable for IoT applications. (iii) Bluetooth, Zigbee [120] consumed low power but the area of coverage is less. Centenaro et.al. used Low power wide area network to connect the node to the base station directly.

Threats due to IoT:
IoT is a disruptive technology with a lot of data. One sticking point in IoT is the insidious security risks. There are no serious security quality assurance checks in their product development cycle. IoT enabled Mirai Botnet in 2016 to combat threats against insecure IoT devices. If IoT sensors are compromised, massive compliance and legal issues would crop in. Unsecured gateways in an organization provides a pathway for cybercriminals. With 5G, huge data, energy conservation, wideband is achievable at the cost of inflated infrastructure, health hazards due to waves, and impermeability to solid obstacles. These challenges [73] are insurmountable. Hash-based techniques and firewalls are used to secure RFID Tags.

Mitigations :
IoT must be secured from hardware, software, and OS. To prevent DoS (Denial-of-Service) Attack, DTLS and IPSec are used to verify the host address. These protocols are also used for authentication and encryption. Currently existing routing protocols are insecure. Decentralized topology is preferred for mitigating threats. Applications, Management, Data Analytics are decentralized using a distributed model referred to as Fog Computing. [137]. Object-based security with digital signatures is secured than peer-topeer encryption. [262]. The intrusion detection system (IDS) is required to prevent unauthorized access to IoT. [153]. But these introduce challenges to power, bandwidth, and network. Legislations should be made mandatory as in Verizon for IoT [281]. Other issues of research are IoT mobility, Standardization, etc., with the integration of IoT in wearables, IoT is the thrust area vulnerable to cyber security threats in the near future.

Smart Academics Management:
Smart classroom is a pivotal innovative tool for teaching. A prototype is set using raspberry pi and a raspberry pi camera to record lectures of faculties. Recorded lectures later uploaded into the website could be accessed with a given username and a password provided for each student. The quality of education is a vital demand in today's competitive setting. Technology has affected us in each facet. Intuitive categories are a progressive approach of education within the education situation in India that offer quality teaching and learning opportunities to lecturers and students by serving them to longer devotion towards teaching, better construct formation and educational action. New teaching ways uses instructional material, 3D animated modules and videos.
(i) Implementation: The Raspberry Pi module along with a 5MP color camera module is used for recording the lecture. Using Raspivid, lectures are recorded .Once recorded, the recorded video is uploaded using Raspbian software. Figure 6. Smart Academics Implementation The recorded lectures are uploaded in a google drive as shown in Figure 6. This is accessible by the student using a username and a password. The website for the students is designed using XAMPP and PHP software. A database is created with the help of MySQL in XAMPP and the database host.
The apache software in XAMPP can be used to generate the request and response for the website. The login credentials is the request and the output received is the response.
If the entered username and password (i.e.) fetched values is the same as that of the values stored in the db then the user is redirected to the link where the materials are available.  These days everything is "smart" starting from vehicles and homes to nanobots. The concept of IoT has played an important role in our day to day life. Technology has immensely developed over a period of time and the real usage of this technology in academics is noticeable during the pandemic situation. This eco-friendly concept would come in handy to students who miss their classes during unavoidable circumstances. The smart classroom is an enhanced sharing mode that improves teaching and learning opportunities by a group of students with limited resources.

Futuristic Research Inclinations:
Information-centric network (ICN) [40] forms the future of IoT. IoT devices provide content. It targets content by name and not by location. It supports multicasting and mobility. It integrates network functionalities in the form of content rather than a location address. [295].Challenges faced by IoT are at the technology level, communication and networking level, and intelligence level. Smart objects integration is done at the technology level. At the communication and networking level, challenges are involved in the networking and ubiquitous service provisions. Data fusion and service detection is done at the intelligence level. IoT cannot be globally deployed without a precise architecture. IoT-A -Architecture -seamlessly integrates heterogeneous devices. Handling heterogeneous devices is a major task. Effective measures are required to handle the increasing number of IoT devices and Big Data. [180].Streaming is used for collecting the data from heterogeneous devices, process it, and make it available in realtime without latency [203,63]. With proliferating wearable devices and mobiles, IoT is embarking towards personalized health care. [152]. Intelligent algorithms are used for analyzing specific diseases. Mobile apps collect jogging activity, tracking, and life -logging data. These aspects along with specific algorithms are used in IoT personalized healthcare solutions [202]. IoT serves as a tool for quality education. [150]. IoT supports teaching and promotes academic performance. 5G and IoT will form the mobile broadband [127] in the future and thrive the growth of IIoT. [141]. Human 4.0 augments human with features that are integrated with the neural system. [237].This technology makes IoT fully autonomous with a foreseeable future. CloudIoT bridges Cloud and IoT and is gaining momentum. [12] .Digitization improves economy, management control and provides hybrid solutions. [86]. Forensic vigilance is required for smart cities. Digital Witness is collected with a privacy warranty. [15]. Security depends on the data, location of data, tools [195] used to analyze data etc., Conjoining cloud forensics with client forensics, and logistical solutions are obtained for an Internet-of-Anything (IoA) Era, where swarms of resources are connected. Block Chain provides viable de-centralized secured management solutions but hashing functions and the key could be compromised. [193]. The Government is working towards standardization [271,129,100]. Mohammad (2013) et.al. used user-centered tools such as Microsoft Gadgeteer to thrive interest in the user towards IoT. Future IoT would have recyclable materials, power independent systems with embedded intelligence. [136]. Future IoT architecture should use narrowband and cater to hardware and software solutions. [248]. IoT is deployed in e-Learning for virtual labs and the global library [34] to improve the teaching-learning process [185]. As a part of digital learning, M-Learning is in the earlier stage of research. [297]. Internet of Medical Things (IoMT) is used to manage medical services and healthcare workers by connecting medical devices and applications. [80]. Information skills, communication skills, strategic skills, and content creation skills are required besides for IoT operability. [276].

CONCLUSION:
Internet-of-Things is a proven technology in the field of automation connecting the virtual world of intelligent objects to the real world of things. It generates and processes data from a lot of implanted devices. With increased connectivity, quality of life, optimized energy, time, cost, and labor, IoT improves by preventing unplanned downtime. Automation improves efficiency, connectivity, and integration. [289]. With data-rich resources newer innovations with burgeon. With IoT, comfort, local-to-global connectivity, eco-friendly support, quality of life, and safety increases. Hazardous ecosystems could be remotely controlled and monitored. Organizations connect the physical world (hardware) to the digital world (software, data analytics) and build an organizational structure to meet the expectations. This article has a systematic insight into the contributions, pre-requisites, research challenges, and architectural design factors integrated into IoT for futuristic remedial measures. Companies need to shift from the traditional approach towards virtual IoT for satisfactory returns. We are heading towards a world where everything will be connected with IoT reaching escape velocity. After the pandemic crisis, based on the virtual usage pattern and social distancing modes, prognostications reveal that IoT and Cloud usage in Education, Healthcare, and Automation would cater to the need of the hour.