Standardized Infrastructure of Low Power Wide Area Networks for IoT

Abstract

As the Internet of Things (IoT) paradigm being a global trend to improve human’s life, the emerging low power wide area network (LPWAN) technologies have attracted both researchers and engineers because of their advantages on kilometer level coverage and uA-level power consumption. There are kinds of leading LPWAN technologies, including Long Range (LoRa), Sigfox, and Narrow-Band IoT (NB-IoT), which occupy most LPWAN industry market. However, current LPWAN market is facing to four challenges, which covers aspects of compliance, reliability, security, and interoperability. Due to the heterogeneous of LPWAN products, manufacturers integrate the LPWAN infrastructure without common standard, resulting in incompliance design. At the meanwhile, because of the lack of integration of appropriate complex infrastructure for LPWAN to improve the reliability and security, the LPWAN system is under the risk (i.e., single point of failure, distributed denial of service). Additionally, to fully utilize the network resources, interoperability of different LPWAN systems has been a popular topic. However, given the lack of common design policy, it is hard to cooperate different LPWAN systems together. These typical issues of LPWAN may cause to incompliant, unreliable, insecure, and inefficient LPWAN ecosystem.

To overcome these typical issues, IEEE 2668 is regarded as a potential way. In IEEE 2668, a standardized infrastructure is defined for IoT, which can be also applied to facilitate the compliance of LPWAN system. Moreover, IEEE 2668 standardized infrastructure recommends series of complex infrastructure in network layer (e.g., server cluster structure, security system) to improve the reliability and security of IoT system. Contributed by IEEE 2668 standardized infrastructure, the interoperability of different LPWAN systems can be simply reached to organizational interoperability. In addition, IEEE 2668 provides a five-level evaluation system, namely IoT Index (IDex) to evaluate all IoT-related things to provide guidance to facilitate the industrial performance. In the thesis, IEEE 2668 is applied to embrace the following four contributions:

1.To deal with the incompliance design of LPWAN, an IEEE 2668-compliant LPWAN infrastructure is defined. The standardized infrastructure aims to provide plug-and-play services between device layer, network layer, application layer to reach the compliant communication service, which is the first time to apply IEEE 2668 framework into LPWAN area. In the standardized infrastructure, the details of LPWAN platform interoperable device (PID), data processing middleware (DPM), digital information specification (DIS), and standardized application programming interfaces (APIs) are introduced. Meanwhile, to evaluate the industrial performance of the new proposed IEEE 2668-compliant LPWAN infrastructure, the compliance index (CDex) is defined. The evaluation outcome revealed that CDex of standardized infrastructure facilitates the index level from 2.6 (non-standard infrastructure) to 4.6, leading the development of system toward IoT best practices (e.g., IDex level should be more than 3.5 in principle.).

2.Single point of failure is a typical reliability issue due to the centralized infrastructure of server. To decrease the impact of single point of failure, the cluster infrastructure can be regarded as an efficient way. However, when the cluster infrastructure is applied to LPWAN, conventional load balancing model will become inefficient in terms of latency and cost due to the existence of radio replication (i.e., A radio packet can be broadcasted to multiple LPWAN radio middleware and forms replications at server.). To deal with the issue, an optimized radio replication combined supermarket model (RRC-SM) is proposed to address the issue caused by radio replication. To reflect the industrial performance of the proposed RRC-SM, a load balancing efficiency index (LBE-Dex) is defined based on IEEE 2668 standardized infrastructure. Evaluation outcome presents that LBE-Dex of RRC-SM can reach to 4.5, which satisfies the requirements of IoT best practices.

3.In network layer of IEEE 2668 standardized infrastructure, security system is recommended to facilitate the security level of IoT system. Given that IoT system (including LPWAN system) is normally equipped with relatively lightweight computation resources of network layer, which may be the potential destination of IoT-driven distributed denial of service attack (IoT-DDoS). Thus, to address the issue, an IEEE 2668-compliant multi-layer IoT DDoS defense system using deep reinforcement learning (DRL-MLIDDS) is proposed with the standardized reward metrics. To evaluate the improvement of the proposed DRL-MLIDDS, an applicability index (ADex) is defined using IEEE 2668 perspective. In the evaluation, ADex presents that the index level of DRL-MLIDDS can reach to 4.4, fulfilling the requirements of IoT best practices.

4.An IEEE 2668-compliant interoperability infrastructure of LPWANs (IEEE 2668-IF-LPWANs) can be generated based on the extension of internet services of IEEE standardized infrastructure. By applying the DIS technology defined by IEEE 2668, IEEE 2668-IF-LPWANs can simply reach to the technical interoperability (TI), syntactic interoperability (SYI), semantic interoperability (SEI), and organizational interoperability (OI). The interoperability index (I2Dex) is presented to showcase that the index level of IEEE 2668-IF-LPWANs reaches to 4.8 for IoT best practices.

Date of Award	28 Mar 2023
Original language	English
Awarding Institution	City University of Hong Kong
Supervisor	Kim Fung TSANG (Supervisor)