118 research outputs found
Isolating SDN Control Traffic with Layer-2 Slicing in 6TiSCH Industrial IoT Networks
Recent standardization efforts in IEEE 802.15.4-2015 Time Scheduled Channel
Hopping (TSCH) and the IETF 6TiSCH Working Group (WG), aim to provide
deterministic communications and efficient allocation of resources across
constrained Internet of Things (IoT) networks, particularly in Industrial IoT
(IIoT) scenarios. Within 6TiSCH, Software Defined Networking (SDN) has been
identified as means of providing centralized control in a number of key
situations. However, implementing a centralized SDN architecture in a Low Power
and Lossy Network (LLN) faces considerable challenges: not only is controller
traffic subject to jitter due to unreliable links and network contention, but
the overhead generated by SDN can severely affect the performance of other
traffic. This paper proposes using 6TiSCH tracks, a Layer-2 slicing mechanism
for creating dedicated forwarding paths across TSCH networks, in order to
isolate the SDN control overhead. Not only does this prevent control traffic
from affecting the performance of other data flows, but the properties of
6TiSCH tracks allows deterministic, low-latency SDN controller communication.
Using our own lightweight SDN implementation for Contiki OS, we firstly
demonstrate the effect of SDN control traffic on application data flows across
a 6TiSCH network. We then show that by slicing the network through the
allocation of dedicated resources along a SDN control path, tracks provide an
effective means of mitigating the cost of SDN control overhead in IEEE
802.15.4-2015 TSCH networks
Alternate marking-based network telemetry for industrial WSNs
For continuous, persistent and problem-free operation of Industrial Wireless Sensor Networks (IWSN), it is critical to have visibility and awareness into what is happening on the network at any one time. Especially, for the use cases with strong needs for deterministic and real-time network services with latency and reliability guarantees, it is vital to monitor network devices continuously to guarantee their functioning, detect and isolate relevant problems and verify if all system requirements are being met simultaneously. In this context, this article investigates a light-weight telemetry solution for IWSNs, which enables the collection of accurate and continuous flowbased telemetry information, while adding no overhead on the monitored packets. The proposed monitoring solution adopts the recent Alternate Marking Performance Monitoring (AMPM) concept and mainly targets measuring end-to-end and hopby-hop reliability and delay performance in critical application flows. Besides, the technical capabilities and characteristics of the proposed solution are evaluated via a real-life implementation and practical experiments, validating its suitability for IWSNs
Evolving SDN for Low-Power IoT Networks
Software Defined Networking (SDN) offers a flexible and scalable architecture
that abstracts decision making away from individual devices and provides a
programmable network platform. However, implementing a centralized SDN
architecture within the constraints of a low-power wireless network faces
considerable challenges. Not only is controller traffic subject to jitter due
to unreliable links and network contention, but the overhead generated by SDN
can severely affect the performance of other traffic. This paper addresses the
challenge of bringing high-overhead SDN architecture to IEEE 802.15.4 networks.
We explore how traditional SDN needs to evolve in order to overcome the
constraints of low-power wireless networks, and discuss protocol and
architectural optimizations necessary to reduce SDN control overhead - the main
barrier to successful implementation. We argue that interoperability with the
existing protocol stack is necessary to provide a platform for controller
discovery and coexistence with legacy networks. We consequently introduce
{\mu}SDN, a lightweight SDN framework for Contiki, with both IPv6 and
underlying routing protocol interoperability, as well as optimizing a number of
elements within the SDN architecture to reduce control overhead to practical
levels. We evaluate {\mu}SDN in terms of latency, energy, and packet delivery.
Through this evaluation we show how the cost of SDN control overhead (both
bootstrapping and management) can be reduced to a point where comparable
performance and scalability is achieved against an IEEE 802.15.4-2012 RPL-based
network. Additionally, we demonstrate {\mu}SDN through simulation: providing a
use-case where the SDN configurability can be used to provide Quality of
Service (QoS) for critical network flows experiencing interference, and we
achieve considerable reductions in delay and jitter in comparison to a scenario
without SDN
Hybrid schedule management in 6TiSCH networks : the coexistence of determinism and flexibility
With the emergence of the Internet of Things (IoT), Industry 4.0 and Cyber-Physical System (CPS) concepts, there is a tremendous change ongoing in industrial applications that is imposing increasingly diverse and demanding network dynamics and requirements with a wider and more fine-grained scale. The purpose of this article is to investigate how a Hybrid Schedule Management in 6TiSCH architecture can be used to achieve the coexistence of applications with heavily diverse networking requirements. We study the fundamental functionalities and also describe network scenarios where such a hybrid scheduling approach can be used. In addition, we present the details about the design and implementation of the first 6TiSCH Centralized Scheduling Framework based on CoMI. We also provide theoretical and experimental analysis where we study the cost of schedule management operations and illustrate the operation of the CoMI-based 6TiSCH Schedule Management
In-band network telemetry in industrial wireless sensor networks
With the emergence of the Internet of Things (IoT) and Industry 4.0 concepts, industrial applications are going through a tremendous change that is imposing increasingly diverse and demanding network dynamics and requirements with a wider and more fine-grained scale. Therefore, there is a growing need for more flexible and reconfigurable industrial networking solutions complemented with powerful monitoring and management functionalities. In this sense, this paper presents a novel efficient network monitoring and telemetry solution for Industrial Wireless Sensor Networks mainly focusing on the 6TiSCH Network stack, a complete protocol stack for ultra-reliable ultra-low-power wireless mesh networks. The proposed monitoring solution creates a flexible and powerful in-band network telemetry design with minimized resource consumption and communication overhead while supporting a wide range of monitoring operations and strategies for dealing with various network scenarios and use cases. Besides, the technical capabilities and characteristics of the proposed solution are evaluated via a real-life implementation, practical and theoretical analysis. These experiments demonstrate that in-band telemetry can provide ultra-efficient network monitoring operations without any effect on the network behavior and performance, validating its suitability for Industrial Wireless Sensor Networks
A dynamic distributed multi-channel TDMA slot management protocol for ad hoc networks
With the emergence of new technologies and standards for wireless communications and an increase in application and user requirements, the number and density of deployed wireless ad hoc networks is increasing. For deterministic ad hoc networks, Time-Division Multiple Access (TDMA) is a popular medium access scheme, with many distributed TDMA scheduling algorithms being proposed. However, with increasing traffic demands and the number of wireless devices, proposed protocols are facing scalability issues. Besides, these protocols are achieving suboptimal spatial spectrum reuse as a result of the unsolved exposed node problem. Due to a shortage of available spectrum, a shift from fixed spectrum allocation to more dynamic spectrum sharing is anticipated. For dynamic spectrum sharing, improved distributed scheduling protocols are needed to increase spectral efficiency and support the coexistence of multiple co-located networks. Hence, in this paper, we propose a dynamic distributed multi-channel TDMA (DDMC-TDMA) slot management protocol based on control messages exchanged between one-hop network neighbors and execution of slot allocation and removal procedures between sender and receiver nodes. DDMC-TDMA is a topology-agnostic slot management protocol suitable for large-scale and high-density ad hoc networks. The performance of DDMC-TDMA has been evaluated for various topologies and scenarios in the ns-3 simulator. Simulation results indicate that DDMC-TDMA offers near-optimal spectrum utilization by solving both hidden and exposed node problems. Moreover, it proves to be a highly scalable protocol, showing no performance degradation for large-scale and high-density networks and achieving coexistence with unknown wireless networks operating in the same wireless domain
A System Architecture for Software-Defined Industrial Internet of Things
Wireless sensor networks have been a driving force of the Industrial Internet
of Things (IIoT) advancement in the process control and manufacturing industry.
The emergence of IIoT opens great potential for the ubiquitous field device
connectivity and manageability with an integrated and standardized architecture
from low-level device operations to high-level data-centric application
interactions. This technological development requires software definability in
the key architectural elements of IIoT, including wireless field devices, IIoT
gateways, network infrastructure, and IIoT sensor cloud services. In this
paper, a novel software-defined IIoT (SD-IIoT) is proposed in order to solve
essential challenges in a holistic IIoT system, such as reliability, security,
timeliness scalability, and quality of service (QoS). A new IIoT system
architecture is proposed based on the latest networking technologies such as
WirelessHART, WebSocket, IETF constrained application protocol (CoAP) and
software-defined networking (SDN). A new scheme based on CoAP and SDN is
proposed to solve the QoS issues. Computer experiments in a case study are
implemented to show the effectiveness of the proposed system architecture.Comment: To be published by IEEE ICUWB-201
Mobility Management in Industrial Iot Environments
The Internet Engineering Task Force (IETF) has defined the 6TiSCH architecture to enable the Industrial Inter-net of Things (IIoT). Unfortunately, 6TiSCH does not provide mechanisms to manage node mobility, while many industrial applications involve mobile devices (e.g., mobile robots or wearable devices carried by workers). In this paper, we consider the Synchronized Single-hop Multiple Gateway framework to manage mobility in 6TiSCH networks. For this framework, we address the problem of positioning Border Routers in a deployment area, which is similar to the Art Gallery problem, proposing an efficient deployment policy for Border Routers based on geometrical rules. Moreover, we define a flexible Scheduling Function that can be easily adapted to meet the requirements of various IIoT applications. We analyze the considered Scheduling Function in different scenarios with varying traffic patterns and define an algorithm for sizing the system in such a way to guarantee the application requirements. Finally, we investigate the impact of mobility on the performance of the system. Our results show that the proposed solutions allow to manage node mobility very effectively, and without significant impact on the performance
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