Table 2 A summary of studies with respect to IoT key challenges and applications

Interoperability

[25,26,27,28, 47,48,49, 71,72,73,74,75]

General issues, IoT platforms and architectures, technical and semantic interoperability

Security and privacy

[1,2,3,4,5,6, 14, 15, 17,18,19,20, 24, 46, 76]

Security and privacy issues, definition and design of secure IoT networks and architecture

Management and control

[12, 18, 23, 26, 43, 71, 73, 77,78,79,80]

IoT layer management and control, device, network, application, data and trust management and control

Architecture

[4, 6, 19, 20, 38, 74, 75, 81,82,83,84,85]

Hardware, cloud centric, SOA, process architectures and conceptual models, application frameworks

Quality of Service

[23, 26, 28, 34, 41, 53, 86,87,88,89,90,91,92,93,94]

Data traffic load, protocols for all layers in IoT architecture, QoS and QoE routine check

Authentication and identification

[12, 16, 17, 23, 45, 50, 95,96,97]

Addressing issues and solutions, IoT integrations with internet protocols (IPv6), authentication and identification issues

Environment, power and energy

[10, 29,30,31,32,33, 37, 67, 68, 85, 98,99,100,101,102]

Involvement of green technology in IoT, design of low power consumption devices and chips, pollution control and management

Smart city, healthcare and transportation

[7, 9, 10, 13, 38, 58, 69, 70, 103,104,105,106,107,108,109,110,111,112,113]

Smart traffic management and control, smart devices for healthcare management, smart vehicles, energy management

Data processing and storage

[26, 41, 43, 66, 87, 114]

Data analysis, visualization, integration issues and solutions

Reliability

[18, 27, 43, 52, 66, 72, 101, 115,116,117,118,119,120,121]

Connectivity, mobility and routing issues, reliability of infrastructure and applications

Scalability

[24, 27, 28, 41, 43, 51, 115]

Scaling issues on large platforms and geographical locations, potential discovery services

Standardization

[12, 43,44,45, 99, 101, 114, 122]

IoT definition, protocols design, architecture standardization, vision and framework design