# Fog Computing Enabling Industrial Internet of Things: State-of-the-Art and Research Challenges
## 3 Industrial Internet of Things Applications and Requirements
### IIoT Application Design Parameters  
To the increasing demand of customers and market requirements, the manufacturing industry is now facing problems in achieving desired goals. Industry 4.0 came up with an innovative idea of automation inside in the industry increasing the production process flexibly. Industry 4.0 key point isM2M communication, in which machines communicate with each other over the Internet. Developing and manufacturing industry, communication of intelligent machines with each other using different technologies depending on the coverage area, give rise to high production and self-regulation of the manufacturing process in an industry. These are the goals of industry 4.0; all this is assured by IT systems as they provide enabling smart technologies. The integration of these heterogeneous devices in a network with other devices and existing communication technologies is also the main requirement for designers. Every IIoT application has critical design goal requirements to improve QoS in providing solutions. These design parameters are:  
* **Energy & Long Battery Life:** Overall network energy should be preserved for better and efficient outcomes. Smart devices should have enough battery storage so that they can use for long time. * **Latency:** Some IIoT applications are time-sensitive, a bound should be there to limit all types of delays including processing, propagation, transmission, and computation. * **Throughput:** Amount of data for processing is different for different applications. It should satisfy the application requirement. * **Network Topology:** How the number of servers (cloud, fog, e-node) and smart devices are placed in a network for better QoS requirements. * **Reliability:** Solutions by IIoT applications demand reliable real-time connectivity. * **Security, Safety & Privacy:** These are very demanding and major requirements for all IIoT applications. For example, inside a smart factory there should be privacy and security such that no one can access the private information. For healthcare applications, patient's information should be safe and not easily accessible and changeable. 3A's; Authentication, Access, and Authorization are steps involved in the strictly secure system. The demand of end to end communication in IIoT applications requires privacy of data as well. Sensors and actuators should be safe from intruders as well as environmental hazards. * **Low Cost:** Smart devices used for IIoT applications should be low cost so that doesn't affect the CAPEX/OPEX. Deployment involved in industry 4.0 should not be so much that will cause loss in marketplace. * **Long Coverage:** A device should be capable enough to cover the desired range. * **Standardization:** So far, there is no such network standardization and is an open challenge for researchers. * **Integration:** IIoT applications are composed of heterogeneous devices and hybrid networks, there are a lot of issues in integration. * **Communication/Enabling Technology:** Communication technology for supporting IIoT application should provide assured performance services. * **Device Maintenance:** Heterogeneous device in an industry 4.0 environment, require constant device management as devices are connected with each other and the Internet. Software Defined Networking (SDN) is used for such failure and changing maintenance issues of devices. * **Monitoring Network:** Wireless, environmental and mobility nature may cause a change in network topology which requires the system to be monitored and managed frequently. * **Configuration & Management of System:** Self-configurable, self-control, reconfiguration functionality in addition of new devices in network. * **Traffic congestion & Overload:** Smart devices will be increased with time in any IIoT application. System should be able to adjust according to the traffic burden and data requirement. * **Mobility:** IIoT applications, such as transportation, inside industry and healthcare devices, have the property of mobility from one place to another.