Eli De Poorter

IETF Standardization in the Field of the Internet of Things (IoT): A Survey

Smart embedded objects will become an important part of what is called the Internet of Things. However, the integration of embedded devices into the Internet introduces several challenges, since many of the existing Internet technologies and protocols were not designed for this class of devices. In the past few years, there have been many efforts to enable the extension of Internet technologies to constrained devices. Initially, this resulted in proprietary protocols and architectures. Later, the integration of constrained devices into the Internet was embraced by IETF, moving towards standardized IP-based protocols. In this paper, we will briefly review the history of integrating constrained devices into the Internet, followed by an extensive overview of IETF standardization work in the 6LoWPAN, ROLL and CoRE working groups. This is complemented with a broad overview of related research results that illustrate how this work can be extended or used to tackle other problems and with a discussion on open issues and challenges. As such the aim of this paper is twofold: apart from giving readers solid insights in IETF standardization work on the Internet of Things, it also aims to encourage readers to further explore the world of Internet-connected objects, pointing to future research opportunities.

Symbiotic Networks: Towards a New Level of Cooperation Between Wireless Networks

In the future, many wireless networks, serving diverse applications, will co-exist in the same environment. Today, wireless networks are mostly optimized in a rather opportunistic and/or selfish way: optimizations methods only use a local view of the network and environment, as they try to achieve the best performance within its own network. The optimizations are very often limited to a single layer and cooperation between networks is only happening through the use of gateways. In this paper, we suggest an alternative paradigm for supporting cooperation between otherwise independent networks, called ‘symbiotic networking’. This new paradigm can take many forms, such as sharing of network resources, sharing of nodes for communal routing purposes and sharing of (networking) services. Instead of optimizing network parameters within the individual networks, symbiotic networking solutions operate across network boundaries. Parameters are optimized between the networks and communal protocols are developed, leading to a more global optimization of the scarce network resources. In this paper, we describe several scenarios which can profit from symbiotic networking and illustrate a strategy for supporting networking protocols which can operate across network boundaries. Ultimately, through the disappearance of network boundaries and the introduction of cross-layer/cross-node/cross-network cooperation, symbiotic networks takes the notion of cooperation to a new level, paving the way for a true network symbiosis.

Platform for benchmarking of RF-based indoor localization solutions

Over the last few years, the number of indoor localization solutions has grown exponentially, and a wide variety of different technologies and approaches are being explored. Unfortunately, there is currently no established standardized evaluation method for comparing their performance. As a result, each solution is evaluated in a different environment using proprietary evaluation metrics. Consequently, it is currently extremely hard to objectively compare the performance of multiple localization solutions with each other. To address the problem, we present the EVARILOS Benchmarking Platform, which enables automated evaluation and comparison of multiple solutions in different environments using multiple evaluation metrics. We propose a testbed-independent benchmarking platform, combined with multiple testbed-dependent plugins for executing experiments and storing performance results. The platform implements the standardized evaluation method described in the EVARILOS Benchmarking Handbook, which is aligned with the upcoming ISO/IEC 18305 standard “Test and Evaluation of Localization and Tracking Systems.” The platform and plug-ins can be used in real time on existing wireless testbed facilities, while also supporting a remote offline evaluation method using precollected data traces. Using these facilities, and analyzing and comparing the performance of three different localization solutions, we demonstrate the need for objective evaluation methods that consider multiple evaluation criteria in different environments.

Enabling direct connectivity between heterogeneous objects in the internet of things through a network-service-oriented architecture

In a future internet of things, an increasing number of everyday objects are connected with each other. These objects can be very diverse in terms of the used network protocols and communication technologies, which leads to a wild growth of co-located networking technologies. Unfortunately, current consumer items are not designed to communicate with co-located devices that use different communication technologies. In addition, commercially available internet of things devices, such as sensor nodes, often use vendor-specific propriety network solutions. As a result, communication between these devices is only possible through the use of gateway nodes, resulting in inefficient use of the wireless medium. To remedy this situation, this paper discusses which features are required to integrate such a diverse number of heterogeneous objects into a single internet of things. In addition, the paper introduces the IDRA architecture, which is designed specifically to enable connectivity between heterogeneous resource-constrained objects. The IDRA architecture has the following advantages. (1) IDRA can connect co-located objects directly, without the need for complex translation gateways. (2) The architecture is clean slate, but supports backward compatibility with existing deployments. (3) Due to its low memory footprint, the architecture can be used in resource-constrained objects. Finally, the paper evaluates the performance of the IDRA architecture and discusses the feasibility of introducing IDRA in existing networks.

Facilitating Sensor Deployment, Discovery and Resource Access Using Embedded Web Services

Smart embedded objects such as sensors and actuators will become an important part of the Internet of Things. With recent technologies, it has now become possible to deploy a sensor network and interconnect it with IPv6 Internet. However, several manual configuration steps are still needed to integrate a sensor network within an existing networking environment. In this paper we describe a novel self-organization solution to facilitate the deployment of sensor networks and enable the discovery, end-to-end connectivity and service usage of these newly deployed sensor nodes. The proposed approach makes use of embedded web service technology, i.e. the IETF Constrained Application Protocol (CoAP). Automatic hierarchical discovery of CoAP servers is one of the key features, resulting in a brows able hierarchy of CoAP servers, up to the level of the sensor resources, which can be accessed both over CoAP and HTTP and through the use of either DNS names or IPv6 addresses. To demonstrate the feasibility of our approach we have implemented the solution and deployed it on a test setup, which is publicly accessible to everyone.

IDRA: A flexible system architecture for next generation wireless sensor networks

Wireless sensor networks consist of embedded devices (sensor nodes), equipped with a low-power radio. They are used for many applications: from wireless building automation to e-health applications. However, due to the limited capabilities of sensor nodes, designing network protocols for these constrained devices is currently very challenging. Therefore, this paper presents the IDRA platform: an information driven architecture designed to support next-generation applications on resource constrained networked objects. IDRA supports simple but useful optimizations at an architectural level. These include support for cross-protocol interactions, energy efficiency optimizations, QoS optimizations (packet priorities, dynamic protocol selection), mobility support and heterogeneous network support. The paper shows how the development of protocols is improved by using an architecture which delegates specific tasks to a central system, decreasing the memory requirements of associated network protocols. A thorough experimental performance analysis demonstrates that IDRA is much more scalable in terms of memory requirements, energy requirements and processing overhead than traditional system architectures. Finally, the paper discusses how the optimizations presented in this paper can be used for the clean-slate design of architectures for other wireless or wired network types.

Web-based platform for evaluation of RF-based indoor localization algorithms

The experimental efforts for optimizing the performance of RF-based indoor localization algorithms for specific environments and scenarios is time consuming and costly. In this work, we address this problem by providing a publicly accessible platform for streamlined experimental evaluation of RF-based indoor localization algorithms, without the need of a physical testbed infrastructure. We also offer an extensive set of raw measurements that can be used as input data for indoor localization algorithms. The datasets are collected in multiple testbed environments, with various densities of measurement points, using different measuring devices and in various scenarios with controlled RF interference. The platform encompasses two core services: one focused on storage and management of raw data, and one focused on automated calculation of metrics for performance characterization of localization algorithms. Tools for visualization of the raw data, as well as software libraries for convenient access to the platform from MATLAB and Python, are also offered. By contrasting its fidelity and usability with respect to remote experiments on dedicated physical testbed infrastructure, we show that the virtual platform produces comparative performance results while offering significant reduction in the complexity, time and labor overheads.

An Information Driven Sensornet Architecture

Most sensor networks do not support QoS or heterogeneity. As a result, current sensor networks are not suited for next-generation applications, such as wireless building automation, process control or medical applications. In this paper, we present an alternative architecture wherein the system is responsible for packet creation and packet manipulation. To support QoS, energy-efficiency and heterogeneity, the system intelligently combines information exchanges from multiple network protocols in a single packet. We demonstrate that this approach is better suited for very demanding applications and prove that this approach is much more scalable, in terms of memory requirements, than tradition system architectures.

GITAR: generic extension for internet-of-things architectures enabling dynamic updates of network and application modules

Abstract The Internet-of-Things (IoT) represents the third wave of computing innovation and relies on small, cheap and/or energy efficient devices, densely deployed in various spaces. Automatically managing, updating and upgrading the software on these devices, particularly the network stacks, with new, improved functionality is currently a major challenge. In this paper we propose GITAR, a generic extension for Internet-of-Things architectures, that enables dynamic application and network level upgrades in an efficient way. GITAR consists of four design concepts which can be applied to any operating system running on IoT/M2M devices. The proof of concept implementation in this paper uses the Contiki OS and the evaluation, based on analytical and experimental methods, shows that GITAR i) is up to 14% more efficient in terms of memory usage and ii) has less or similar run-time CPU overhead as state of the art solutions while offering upgrade functionality down to the network level and iii) can reuse existing Contiki network protocols for dynamic updates without requiring modifications to the code.

Strategies and Challenges for Interconnecting Wireless Mesh and Wireless Sensor Networks

Wireless sensor networks and wireless mesh networks are popular research subjects. The interconnection of both network types enables next-generation applications and creates new optimization opportunities. However, current single-gateway solutions are suboptimal, as they do not allow advanced interactions between sensor networks (WSNs) and mesh networks (WMNs). Therefore, in this article, challenges and opportunities for optimizing the WSN-WMN interconnection are determined. In addition, several alternative existing and new interconnection approaches are presented and compared. Furthermore, the interconnection of WSNs and WMNs is used to study challenges and solutions for future heterogeneous network environments. Finally, it is argued that the use of convergence layers and the development of adaptive network protocols is a promising approach to enable low end devices to participate in heterogeneous network architectures.