Emil A. J. Hansen

Bio: Emil A. J. Hansen is an academic researcher from Aalborg University. The author has contributed to research in topics: Broadcast radiation & Packet forwarding. The author has an hindex of 1, co-authored 1 publications receiving 10 citations.

On Relay Selection Approaches in Bluetooth Mesh Networks

Abstract: Bluetooth Mesh (BM) is a new communication standard, which is designed for the upcoming Internet of Things. It builds on the Bluetooth Low Energy (BLE) protocol and allows devices to extend the range and create a mesh network. BM introduces a publisher/ observer structure where a publisher node can broadcast a packet, known also as an advertisement, and all observers can receive the packet. Typically, in BM networks flooding is used to propagate the advertisements. Flooding is known to suffer from broadcast storm problem and be nonreli-able. To improve packet delivery ratio we propose an approach where only a few nodes, relays, are involved in packet forwarding. Selection of the relay nodes, which is a focus of the paper, is a nontrivial task: on the one hand, a minimization of number of relays is desired, on the other hand, using a minimum dominated set would not provide redundancy. We consider three different relay selection mechanisms and develop their extensions that are capable to operate in a distributed fashion. Their performance is evaluated via extensive simulations.

Latency-Aware Function Placement, Routing, and Scheduling in TSN-based Industrial Networks

Abstract: Industrie 4.0 reinforces advanced technology development to realize Time-Sensitive Networking (TSN) with real-time guarantees. The evolution of traditional industrial- automation systems such as Programmable Logic Controllers (PLCs) to cyber-physical systems by means of virtualization is one of the key enhancements. In this paper, we evaluate the impact of the placement of virtual PLCs (vPLCs) at edge clouds in conjunction with scheduling and routing of Time-Triggered (TT) traffic in 802.1Qbv-based industrial networks. We propose two approaches to solve this problem adopting a multi-objective optimization model. In the first approach, we solve separately the problem of placement and scheduling-routing by using a Mixed Integer Linear Programming (MILP) formulation. While in the second approach, we propose a Simulated Annealing (SA)- based meta-heuristic to solve the joint placement, scheduling, and routing optimization problem. We compare both the algorithms for real-world test cases and validate our solutions using the OMNeT++ simulator.

Understanding the Performance of Bluetooth Mesh: Reliability, Delay, and Scalability Analysis

Abstract: This article evaluates the quality-of-service performance and scalability of the recently released Bluetooth mesh protocol and provides general guidelines on its use and configuration. Through extensive simulations, we analyze the impact of the configuration of all the different protocol’s parameters on the end-to-end reliability, delay, and scalability. In particular, we focus on the structure of the packet broadcast process, which takes place in time intervals known as Advertising Events and Scanning Events . Results indicate a high degree of interdependence among all the different timing parameters involved in both the scanning and the advertising processes and show that the correct operation of the protocol greatly depends on the compatibility between their configurations. We also demonstrate that introducing randomization in these timing parameters, as well as varying the duration of the Advertising Events , reduces the drawbacks of the flooding propagation mechanism implemented by the protocol. Using data collected from a real office environment, we also study the behavior of the protocol in the presence of WLAN interference. It is shown that Bluetooth mesh is vulnerable to external interference, even when implementing the standardized limitation of using only 3 out of the 40 Bluetooth low-energy frequency channels. We observe that the achievable average delay is relatively low, of around 250 ms for over 10 hops under the worst simulated network conditions. However, results prove that scalability is especially challenging for Bluetooth mesh since it is prone to broadcast storm, hindering the communication reliability for denser deployments.

Bluetooth Low Energy Mesh Networks: Survey of Communication and Security Protocols

Abstract: Bluetooth Low Energy (BLE) Mesh Networks enable flexible and reliable communications for low-power Internet of Things (IoT) devices Most BLE-based mesh protocols are implemented as overlays on top of the standard Bluetooth star topologies while using piconets and scatternets Nonetheless, mesh topology support has increased the vulnerability of BLE to security threats, since a larger number of devices can participate in a BLE Mesh network To address these concerns, BLE version 5 enhanced existing BLE security features to deal with various authenticity, integrity, and confidentiality issues However, there is still a lack of detailed studies related to these new security features This survey examines the most recent BLE-based mesh network protocols and related security issues In the first part, the latest BLE-based mesh communication protocols are discussed The analysis shows that the implementation of BLE pure mesh protocols remains an open research issue Moreover, there is a lack of auto-configuration mechanisms in order to support bootstrapping of BLE pure mesh networks In the second part, recent BLE-related security issues and vulnerabilities are highlighted Strong Intrusion Detection Systems (IDS) are essential for detecting security breaches in order to protect against zero-day exploits Nonetheless, viable IDS solutions for BLE Mesh networks remain a nascent research area Consequently, a comparative survey of IDS approaches for related low-power wireless protocols was used to map out potential approaches for enhancing IDS solutions for BLE Mesh networks

Relay Node Selection in Bluetooth Mesh Networks

Abstract: Bluetooth Mesh (BM) is a new communication protocol for the Internet of Things that is used to establish many-to-many device communication. BM allows for easy creation of large connection-less mesh networks using a controlled-flooding propagation mechanism, in which relay nodes broadcast the received messages to all neighbors until the message reaches its destination. This model, however, makes BM networks susceptible to broadcast-storm effects, which can hinder the scalability of the protocol. Opportune relay node selection is therefore of critical importance to control network traffic and improve network performance. This paper focuses on the choice of relay selection algorithms suitable for BM networks. In particular, different centralized, decentralized, and localized algorithms based on Connected Dominating Set (CDS) are evaluated and compared.

QoS enabled heterogeneous BLE mesh networks

Abstract: Bluetooth Low Energy (BLE) is a widely known short-range wireless technology used for various Internet of Things (IoT) applications. Recently, with the introduction of BLE mesh networks, this short-range barrier of BLE has been overcome. However, the added advantage of an extended range can come at the cost of a lower performance of these networks in terms of latency, throughput and reliability, as the core operation of BLE mesh is based on advertising and packet flooding. Hence, efficient management of the system is required to achieve a good performance of these networks and a smoother functioning in dense scenarios. As the number of configuration points in a standard mesh network is limited, this paper describes a novel set of standard compliant Quality of Service (QoS) extensions for BLE mesh networks. The resulting QoS features enable better traffic management in the mesh network, providing sufficient redundancy to achieve reliability whilst avoiding unnecessary packet flooding to reduce collisions, as well as the prioritization of certain traffic flows and the ability to control end-to-end latencies. The QoS-based system has been implemented and validated in a small-scale BLE mesh network and compared against a setup without any QoS support. The assessment in a small-scale test setup confirms that applying our QoS features can enhance these types of non-scheduled and random access networks in a significant way.

Exploring data collection on Bluetooth Mesh networks

Abstract: This work evaluates sporadic data collection on a Bluetooth Mesh network, using the OMNET++ INET simulator. The data collector is a roaming sink node, which could be a smartphone or other portable device, carried by a pedestrian, a biker, an animal, or a drone . The sink node could connect to a mesh network in hard-to-reach areas that do not have internet access and collect sensor data . After implementing Bluetooth Mesh relay extensions, Low Power, and Friend features in OMNET++, we were able to propose and evaluate algorithms for mobility-aware, adaptive, routing of sensor data towards the sink node. One variation of a proposed routing algorithm achieved a 173.54% increase in unique data delivered to the sink node compared to Bluetooth Mesh’s default routing algorithm. In that case, there was only a 4.63% increase in energy consumption for the same scenario. Also, the delivery rate increased by 111.82%.