Slavica Tomovic

SDN control framework for QoS provisioning

This paper presents new Software Defined Networking (SDN) control framework for Quality of Service (QoS) provisioning. The proposed SDN controller automatically and flexibly programs network devices to provide required QoS level for multimedia applications. Centralized control monitors state of the network resources and performs smart traffic management according to collected information. Beside QoS provisioning for priority flows, the proposed solution aims at minimizing degradation of best-effort traffic. The experimental results show significant performance improvement under high traffic load compared to traditional best-effort and IntServ service models.

SDN Based Mobile Networks: Concepts and Benefits

Mobile Internet traffic is expected to grow faster than the fixed Internet traffic in a near future. Since, today’s broadband networks are approaching theoretical limits in terms of spectral efficiency per link, mobile operators are compelled to seek for new solutions that will be able to accommodate the expected traffic growth and improve their position in the competitive market. Addressing those challenges with current inflexible, not scalable and complex architecture is very hard, if possible at all. Software defined networking (SDN) is a new networking architecture paradigm that holds great promise to overcome many of mentioned limitations and provides required improvements in performance by decoupling control functions from underlying physical infrastructure. In this paper, we explain key reasons for transition to SDN based mobile networks and briefly describe several proposals of design scenario. Special emphasis is placed on SDN’s contribution to more efficient inter-cell interference management, traffic control and network virtualization.

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.

Software-Defined Fog Network Architecture for IoT

Rapid increase in number and diversity of Internet-connected devices raises many challenges for the traditional network architecture, which is not designed to support a high level of scalability, real-time data delivery and mobility. To address these issues, in this paper we present a new model of Internet of Things architecture which combines benefits of two emerging technologies: software-defined networking and Fog computing. Software-defined networking implies a logically centralized network control plane, which allows implementation of sophisticated mechanisms for traffic control and resource management. On the other hand, Fog computing enables some data to be analysed and managed at the network edge, thus providing support for applications that require very low and predictable latency. In the paper, we give detailed insight into the system structure and functionality of its main components. We also discuss the benefits of the proposed architecture and its potential services.

Performance comparison of QoS routing algorithms applicable to large-scale SDN networks

In Software Defined Networking (SDN) the network control plane is decoupled from the data plane and centralized at programmable controller. One of the advantages of centralized control is possibility to efficiently implement traffic engineering mechanisms, that are still lacking in todays backbone networks due to instability of distributed routing protocols and high management complexity. In this paper, we analysed suitability of different routing algorithms for dynamic setting up of performance guaranteed traffic tunnels in backbone SDN networks. Two routing constraints were considered: bandwidth and path delay. Beside bandwidth rejection ratio, which is commonly used as performance indicator for QoS (Quality of Service) routing algorithms, in the context of SDN low computational time is pointed out as important requirement.

SDN-based concept of QoS aware heterogeneous wireless network operation

Software defined networking (SDN) is a new paradigm for wired networks which cleanly decouples control and the date plane, leaving all control functionality to logically centralized entity. By centralizing network intelligence it provides better visibility of the network conditions, and hence allows more sophisticated traffic management. In this paper, we investigate how the adoption of SDN concept can improve efficiency of heterogeneous wireless environments. We present architectural solution for SDN-based wireless networks, and elaborate on opportunities it provides from various perspectives. In order to exploit benefits of scalable cloud infrastructure, integration of Network Function Virtualization (NFV) is proposed. In particular, the proposed architectural solution allows fast deployment of new services for network operators, gives flexible content delivery options for application providers, and provides improved quality of experience (QoE) for end users.

Fast and efficient bandwidth-delay constrained routing algorithm for SDN networks

In this paper, we propose a new routing algorithm which calculates bandwidth-delay constrained routes in the fast and efficient manner. The algorithm is designed for the software-defined backbone networks, where the control plane is separated from the data plane and logically centralized. Besides providing the required quality of service (QoS), the algorithm aims to maximize utilization of network resources, as that is the major interest of the infrastructure providers. To reduce the computational complexity of this complex traffic engineering task, we consider the control framework which classifies traffic flows in a finite number of categories based on the level of delay sensitivity. The simulation results show that the proposed approach to QoS provisioning, although relatively simple, leads to smaller amount of rejected QoS requests under a wide range of system parameters than the competitive complex solutions.

Allocation algorithm for handling multiple applications in software-defined WSN

In this paper we consider the problem of hosting multiple applications in software-defined wireless sensor networks (SD-WSNs). The applications vary in terms of terms of the number and type of sensing tasks required. Since WSN nodes are very resource constrained, one of the major challenges when scheduling the sensing tasks is to balance the energy consumption and maximize the operational time of the network. In that regard, we propose a new task allocation strategy which exploits knowledge of the network routes and information about residual energy of sensor nodes in order to improve the system energy efficiency and resource utilization. Through simulations we have evaluated performance of the proposed algorithm and the impact of several parameters on its behaviour.

Energy Efficient Target Coverage in Partially Deployed Software Defined Wireless Sensor Network

Limited energy resources of sensor nodes are one of the main weaknesses of wireless sensor networks (WSNs). It has long been recognized that conventional methods of data transmission in WSNs are energy inefficient. However, implementation of coordinated, energy-aware routing and power control strategies among sensor nodes is difficult due to distributed network control. Software defined networking (SDN) is a new networking paradigm which overcomes this issue by decoupling the network control and data planes. As an emerging technology, originally envisioned for wired networks, SDN cannot be expected to completely replace traditional WSNs in near future. Therefore, in this paper, we investigate how to save energy in partially deployed software-defined WSN (SD-WSN). In particular, the paper considers the scenario of WSN deployed for monitoring set of targets with known locations, and analyses how the incremental SDN deployment and various power- mode switching policies could affect the WSN lifetime.

Bandwidth-delay constrained routing algorithms for backbone SDN networks

In this paper we analyzed suitability of different routing algorithms for establishing bandwidth-delay constrained traffic tunnels in SDN backbone networks. Bandwidth rejection ratio was used as indicator of algorithms ability to efficiently utilize network resources. Through set of simulations on two real backbone topologies we showed that network topology can affect algorithms performance, and can lead to biased results. Also, we pointed out problem of high complexity of existing traffic engineering (TE) solutions, which often cannot perform calculations in real-time. Since in SDN networks the controller processing latency can turn out to be a non-negligible factor in the total round-trip latency, we explained heuristic techniques for reducing computation time of bandwidth-delay constrained algorithms and provided illustrative results showing how they impact BRR performance.