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Top1. Introduction
An intelligent building (Bo et al., 2014; Huang et al., 2015; Zhang et al., 2014; Li et al., 2013; Son et al. 2011; Bruno et al., 2014) can monitor and control security, lighting, fire safety and many other systems in a building. It can significantly improve occupant comfort, simplify operation of building systems, and reduce energy consumption and operating costs.
The foundation of intelligent building is the large number of smart devices. These devices are usually connected, and form a very large network. The network is named as intelligent building network (IBNet) in this paper.
However, one challenge here is the IBNet management. So far, many smart devices only support on-site configuration and upgrade. Consequently, it is time-consuming to update configurations (e.g., routing policies and security rules) one device by one device.
In this paper, the researchers propose software defined networking (SDN)-based IBNet to eliminate the problem mentioned above. Recent years, SDN (Bruno et al. 2014; Kretutz et al., 2013; Lantz et al. 2010; Drutskoy et al., 2013; Handigol et al., 2012) is proposed as the next generation network technology, and it can be easily managed. Thus, the researchers expect that with this new technology, the IBNet can also be easily managed. However, the research questions are:
- 1.
Is SDN architecture proposed for general networks suitable for IBNet?
- 2.
Can protocol stacks in smart devices be extended to support SDN protocols?
- 3.
How can the researchers balance requirements of security (Huang et al. 2015) and performance in the newly designed network?
In order to study these questions, the authors build a prototype: SBuilding. The prototype is inspired from SDN: network devices become programmable in SBuilding. SBuilding is compared to other networking technologies, the advantages are summarized.
The main problem in SBuilding is OpenFlow (McKeown et al. 2008; Vu et al., 2012). OpenFlow is the most widely used protocol suite between a SDN controller and network devices. However, the standard version of OpenFlow does not support smart devices.
In order to solve this problem, the authors have designed a protocol stack in smart devices to support OpenFlow. Also, the authors have integrated lightweight security mechanisms in the extended OpenFlow to secure the communications. Both theoretical analysis and practical evaluation are used to confirm that the performance of these mechanisms are acceptable.
In summary, main contributions of this paper are as follows:
- 1.
A SDN-based IBNet (SNet) for intelligent building is proposed. Its advantages and disadvantages comparing to several current network architectures are analyzed;
- 2.
OpenFlow is extended to support smart devices in intelligent buildings. Its security mechanisms are also designed;
- 3.
The researchers use the model checking approach, which is a formal verification technology, to verify proposed security mechanisms;
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Performance of extended OpenFlow is studied; the advantages and disadvantages are summarized.