9020 IEEE INTERNET OF THINGS JOURNAL, VOL. 6, NO. 5, OCTOBER 2019 Design and Development of an IoT Gateway for Smart Building Applications Aditya Nugur , Manisa Pipattanasomporn, Senior Member, IEEE, Murat Kuzlu, Senior Member, IEEE, and Saifur Rahman, Fellow, IEEE Abstract—Due to the depletion of energy resources and load management at the level of building scale would lead to increased energy demand, there is an increased focus on the significant overall energy saving. Thus, smart building loads energy consumption and management in buildings. Many build- which can communicate their power consumption are being ing energy management (BEM) software platforms are com- mercially available to monitor and control energy consumption. developed. These platforms are hosted on the physical hardware within Advancements in recent communication technologies pro- the building, due to which the hardware specifications limit moted smooth development of such smart devices giving birth their performance. To address this limitation, cloud technology to a new paradigm of connected things called the Internet of emerged which facilitates software to be deployed at a remote Things (IoT). It is speculated that by 2020, IoT will comprise location that has scalable hardware resources. Conventional BEM software can leverage such a cloud platform to offer scalable and up to 26 billion interconnected devices [2]. Due to this grow- maintenance-free installation. Once hosted on a remote cloud ing number of smart devices, there is an increasing need for the platform, BEM software lacks direct connectivity to building development of a unified building energy management (BEM) sensors/controllers, hence requires a device to support remote platform. This platform encompasses loads of different proto- accessibility. Most devices are bound to a local area network cols and applications, thereby, making it agnostic to the device and therefore, need an additional functional layer on top of its communication stack to perform network address trans- protocol. Conventional BEM systems are hosted physically lation (NAT)-Traversal. This functionality is implemented on on hardware resource within a building vicinity. Due to this a scalable software which connects to the devices in the network deployment, its performance is always limited by the installed and acts as a gateway for cloud-based BEM software to access hardware capability and cannot be considered scalable. Such devices in the local area network. Any message sent to this gate- hardware constraints defined problems are a prevalent problem way is translated to a respective device protocol. This paper describes the design and implementation of such an Internet in the domain of software engineering. For supporting scalabil- of Things (IoT) gateway for a cloud-based BEM system that ity, a software solution must have access to scalable physical requires support for BACnet, Modbus, and HTTP RESTful hardware resources along with high maintenance standards. interface devices. This led to the advent of a cloud computing technology in Index Terms—Building energy management, cloud computing, which computation and software maintenance is taken care at fog computing, Internet of Things (IoT), IoT gateway. a remote facility from where the data is retrieved. Leveraging on this technology, hosting BEM solution on a cloud service upgrades conventional BEM software in following aspects. I. INTRODUCTION 1) Scalability: Hosting on cloud platform, BEM solution ITH increasing global energy requirements, it is nec- has scalable access to hardware resources. BEM soft- W essary to monitor and manage energy consumption. ware can monitor and manage any number of devices in Residential and commercial customers contribute to 40% of building vicinity by scaling on demand. Hence, a sin- the total power consumption in 2016 [1]. Hence, efficient gle instance of cloud-based BEM solution can support multiple buildings. Manuscript received April 17, 2019; accepted June 23, 2019. Date of publication July 1, 2019; date of current version October 8, 2019. This 2) Remote Accessibility: When opted to host on public work was supported in part by the U.S. Department of Energy under Grant cloud platform, hosted BEM solution offers accessibil- DE-EE-0006352. (Corresponding author: Aditya Nugur.) ity to dashboard multiple buildings onto single screen A. Nugur was with the Bradley Department of Electrical and Computer Engineering, Advanced Research Institute, Virginia Tech, Arlington, which can be administered from anywhere on planet. VA 22203 USA. He is now with the Research and Development 3) Ease of Deployment: A cloud-based platform can be Department, KE2therm Solutions Inc., Washington, MO 63090 USA (e-mail: deployed without any physical intrusion. Support to a [email protected]). M. Pipattanasomporn is with the Smart Grid Research Unit, Department of new device can be added by modifying source code on Electrical Engineering, Chulalongkorn University, Bangkok 10330, Thailand, cloud. Additionally, once deployed, software availability and also with the Advanced Research Institute, Virginia Tech, Arlington, and maintenance is taken care by cloud provider. VA 22203 USA (e-mail: [email protected]). M. Kuzlu is with the Department of Engineering Technology, Old Dominion 4) Disaster Recovery: With growing software vulnerability University, Norfolk, VA 23529 USA (e-mail: [email protected]). concerns, by hosting BEM software on cloud platform, S. Rahman is with the Bradley Department of Electrical and Computer it can harness highest quality of security expertise and Engineering, Advanced Research Institute, Virginia Tech, Arlington, VA 22203 USA (e-mail: [email protected]). provides direct access to the source code to manage Digital Object Identifier 10.1109/JIOT.2019.2926099 software updates and rectify vulnerabilities. 2327-4662 c 2019 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information. Authorized licensed use limited to: to IEEExplore provided by University Libraries | Virginia Tech. Downloaded on June 07,2020 at 15:21:42 UTC from IEEE Xplore. Restrictions apply. NUGUR et al.: DESIGN AND DEVELOPMENT OF IoT GATEWAY FOR SMART BUILDING APPLICATIONS 9021 5) Data Storage and Analysis: Energy consumption statis- this issue, many multiprotocol scalable integration architec- tics are crucial to determine faulty environment or tures were developed [8], [9]. However, all these architectures optimize building energy consumption. This requires were not targeted to work in conjunction with cloud-based aggregation of huge amount of datasets (in Gigabytes) BEM software. and application of resource intensive algorithms. Cloud With the advent of cloud computing, significant changes services being data centers with large storage spaces took place in the way software architecture is designed. These are necessary to facilitate this advantage. Additionally, approaches were applied in the development of BEM soft- advancements in machine learning domain enable real ware as well. In [10], an IoT architecture based on OPC.NET time control over building load profiles. As these algo- specification was developed. However, it addressed only rithms get fine-tuned, data collection and analysis may devices which follow OPC.NET specifications and do not sup- become a mandatory need. port RESTful application program interface (API) interfaced 6) Smarter Grid: Being capable of hosting multiple build- devices. ings on a single platform, a cloud-based BEM solution In [11], a detailed study was presented which explains can have varied data inputs from an entire locality, giv- how an IoT gateway performs by fitting in fog computing ing greater insights to power generating plants and hence architecture (fog computing is the approach where a part of can efficiently manage demand and promote smarter cloud computation occurs at the edge of the network). In [12], pricing scale. This feedback loop on large scale paves IoT gateways were demonstrated as distributed nodes which way toward smart cities. perform machine-to-machine communications for discovery Hence, a cloud-based BEM software can extend the horizon and management of connected vehicles. Authors in [13]–[17] of conventional BEM system offerings. Although, the cloud proposed how fog computing is a more stable architecture than architecture could streamline BEM software adoption, it still cloud computing. suffers from a fundamental flaw, i.e., the feasibility of the Today, there are also a number of hardware, software, cloud solution. Although, recently developed smart devices and end-to-end vendors who commercially deploy IoT gate- are adaptive to the cloud architecture by supporting remote ways. Companies, such as Dell, Cisco, Intel, etc., provide accessibility, the majority of legacy devices are bounded within commercial-scale smart IoT gateways. These IoT gateway a local area network. products [18]–[20] have a wide range of physical input mod- For a cloud-based BEM software to have comprehensive ules from serial connections to wireless connections. However, control on all devices in a building, each device in the build- these IoT gateways require the acquisition of devices made ing automation space requires implementing network address explicitly for the proprietary IoT gateway and targets sensor translation (NAT)-Traversal as an additional layer on top its devices. Additionally, these IoT gateway devices are compati-