Gordana Gardasevic

Testing Protocols for the Internet of Things on the EuWIn Platform

Several approaches have been considered by research community as possible enablers for the Internet of Things (IoT) implementation. This paper presents the results obtained by testing and comparing three different solutions. In particular, we compare a centralized solution based on software defined network (SDN), called software defined wireless networking (SDWN), with two standard and distributed solutions, that are ZigBee and IPv6 over low-power wireless personal area networks (6LoWPAN). SDWN uses a centralized network layer protocol, where routing policies are defined by an external controller that can be positioned anywhere in the network. The other two solutions are actually the most common protocol stacks for wireless sensor networks, and they both use a distributed routing protocol. The comparison is achieved by experimentations performed on the European Laboratory of Wireless Communications for the Future Internet (EuWIn) platform developed within the network of excellence, NEWCOM#. Results show that SDWN is the best solution in static or quasi-static environments, while the performance degrades in highly dynamic conditions. However, ZigBee has a good reactivity to environmental changes. This paper reports the evaluation of several performance metrics, including packet loss rate, round-trip-time, and overhead generated in the network, under different conditions and considering different kinds of traffic.

The IoT Architectural Framework, Design Issues and Application Domains

The challenge raised by the introduction of Internet of Things (IoT) concept will permanently shape the networking and communications landscape and will therefore have a significant social impact. The ongoing IoT research activities are directed towards the definition and design of open architectures and standards, but there are still many issues requiring a global consensus before the final deployment. The paper presents and discusses the IoT architectural frameworks proposed under the ongoing standardization efforts, design issues in terms of IoT hardware and software components, as well as the IoT application domain representatives, such as smart cities, healthcare, agriculture, and nano-scale applications (addressed within the concept of Internet of Nano-Things). In order to obtain the performances related to recently proposed protocols for emerging Industrial Internet of Things applications, the preliminary results for Message Queuing Telemetry Transport and Time-Slotted Channel Hopping protocols are provided. The testing was performed on OpenMote hardware platform and two IoT operating systems: Contiki and OpenWSN.

On the performance of 6LoWPAN through experimentation

The Internet of Things (IoT) research activities are oriented towards the standardisation of communication protocols and platforms for globally interconnected smart objects. 6LoWPAN is a standardised protocol stack aiming at providing the seamless interconnection between IPv6 Wireless Sensor Network (WSN) and Internet, while maintaining low-power consumption. In this paper, we present and investigate the performance of 6LoWPAN, being one of the most promising solutions for the implementation of IoT paradigm. The evaluation is performed through experimentation on the “European Laboratory of Wireless Communications for the Future Internet” (EuWIn) facilities developed within the Network of Excellence, NEWCOM#, at the University of Bologna. We report results in terms of average round-trip-time, packet loss rate and throughput for different payload sizes and number of hops, both for unicast and multicast traffics.

CoAP protocol for Web-based monitoring in IoT healthcare applications

Internet of Things (IoT) for healthcare applications is an emerging research field that has gained a lot of attention in the last few years. The paper presents the IoT remote healthcare monitoring system that provides the patients conditions through Web browser. For simulation purposes, we use Contiki OS with 6LoWPAN protocol stack, and Cooja, the built-in Contiki simulator. CoAP is selected as application level protocol for remote data access and representation.

Dynamic weighted round robin in crosspoint queued switch

Achievement of desired performance levels (quality of service - QoS) in switches and routers is one of the most important tasks in switching systems. This implies providing guaranteed throughput, cell loss probability, average and maximal latency within the required bounds. To achieve this task in crosspoint queued switch, we implemented the weighted round robin (WRR) algorithm. We showed that WRR algorithm can achieve very good performance levels regarding the throughput and latency, but had major drawback because it require knowledge of arrival traffic. To overcome this problem, we implemented and presented in this paper the dynamic weighted round robin (DWRR) algorithm that can work with unknown arrival traffic. We showed that DWRR can achieve same performance as WRR, without the need for incoming traffic information, which makes it suitable for practical implementation.

Performance analysis of crosspoint queued crossbar switch with weighted round robin scheduling algorithm under unbalanced bursty traffic

The possibility of enabling Quality of Service (QoS) in crosspoint-queued packet switches has been presented in this paper. For this purpose, the weighted round robin algorithm was simulated and analyzed. The packet delay represents one of the most important parameters in modern networks. Therefore, besides the throughput, we have been investigating the delay that crosspoint queued switch introduce, under bursty unbalanced traffic. Along with the average delay, the truncated maximum cell delay is analyzed. Results show that the weighted round robin scheduling algorithm achieves throughput similar to output-queued switch, under unbalanced bursty traffic, while maintaining low cell delay.

Performance evaluation of Dual Crosspoint Queued crossbar packet switch

This paper presents an analysis of new Dual Crosspoint Queued (DCQ) crossbar switch architecture. It is well-known that in order to achieve performance guarantees, the priority separation of incoming traffic is necessary. Therefore, we modified CQ crossbar switch with the separation of different traffic flows, by implementing two buffers in each crosspoint of switch fabric. Different round robin based scheduling algorithms are presented and analyzed. With the particular attention on the cell delay and cell loss probability, results of simulations show that proposed switch architecture can achieve desired QoS only for the high priority traffic flow.

A Heterogeneous IoT-Based Architecture for Remote Monitoring of Physiological and Environmental Parameters

A heterogeneous Internet of Things (IoT) architecture for remote health monitoring (RHM) is proposed, that employs Bluetooth and IEEE 802.15.4 wireless connectivity. The RHM system encompasses Shimmer physiological sensors with Bluetooth radio, and OpenMote environmental sensors with IEEE 802.15.4 radio. This system architecture collects measurements in a relational database in a local server to implement a Fog node for fast data analysis as well as in a remote server in the Cloud.

A new approach to dynamic routing in SDN networks

Todays networks are dominantly based on the Shortest Path First (SPF) routing algorithms. These algorithms assign weighting factors to links statically, such that the routing tables are recalculated only when a topology change occurs. As a result, the network traffic is often unevenly distributed, thus causing the congestion on some links even when the total traffic load is not particularly high. In this paper, we discuss how the above-mentioned problem could be alleviated by applying dynamic routing in Software-Defined Networks (SDNs). We propose three new dynamic routing algorithms and present their OpenFlow-based implementation. The efficiency of the proposed solutions has been verified on two OpenFlow network topologies in Mininet emulator. The obtained results show that the proposed solutions could significantly improve the network throughput in comparison to SPF routing model used in traditional networks.

Performance evaluation of OpenWSN operating system on open mote platform for industrial IoT applications

Wireless Sensor Networks (WSNs) represent one of the key technologies in Industrial Internet of Things (IloT) applications. Recently, the Open Mote platform has drawn significant attention to IIoT research community. The Open Mote is a representative of new generation open-hardware platforms that is particularly adapted to IIoT applications. The Open WSN is IoT operating system (OS) that incorporates the complete communication protocol stack for industrial WSN. This paper presents the Open WSN protocol stack and results of performance evaluation of entire Open WSN implementation on Open Mote hardware platform. Performance evaluation is based on traffic generation and measurement of relevant metrics. The selected metrics are: round-trip time, packet loss rate and throughput.