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openaire: EC/H2020/688203/EU//bIoTope | openaire: EC/H2020/856602/EU//FINEST TWINS In an Internet of Things (IoT) environment, a large volume of potentially confidential data might be leaked from sensors installed everywhere. To ensure the authenticity of such sensitive data, it is important to initially verify the source of data and its identity. Practically, IoT device identification is the primary step toward a secure IoT system. An appropriate device identification approach can counteract malicious activities such as sending false data that trigger irreparable security issues in vital or emergency situations. Recent research indicates that primary identity metrics such as Internet Protocol (IP) or Media Access Control (MAC) addresses are insufficient due to their instability or easy accessibility. Thus, to identify an IoT device, analysis of the header information of packets by the sensors is of imperative consideration. This paper proposes a combination of sensor measurement and statistical feature sets in addition to a header feature set using a classification-based device identification framework. Various machine Learning algorithms have been adopted to identify different combinations of these feature sets to provide enhanced security in IoT devices. The proposed method has been evaluated through normal and under-attack circumstances by collecting real-time data from IoT devices connected in a lab setting to show the system robustness.

In recent years, noticeable progress has been made in the development of quantum equipment, reflected through the number of successful demonstrations of Quantum Key Distribution (QKD) technology. Although they showcase the great achievements of QKD, many practical difficulties still need to be resolved. Inspired by the significant similarity between mobile ad-hoc networks and QKD technology, we propose a novel quality of service (QoS) model including new metrics for determining the states of public and quantum channels as well as a comprehensive metric of the QKD link. We also propose a novel routing protocol to achieve high-level scalability and minimize consumption of cryptographic keys. Given the limited mobility of nodes in QKD networks, our routing protocol uses the geographical distance and calculated link states to determine the optimal route. It also benefits from a caching mechanism and detection of returning loops to provide effective forwarding while minimizing key consumption and achieving the desired utilization of network links. Simulation results are presented to demonstrate the validity and accuracy of the proposed solutions., Comment: The article under the review in IEEE/ACM Transactions on Networking journal

In this paper, we propose a multi-zone service control scheme to maximize the performance of each service zone when a large number of cellular service zones and Device-to-Device (D2D) service zones are composed into the 5G cellular network. This paper also improves performance of service zone by dividing traffic into real-time traffic and non-real-time traffic in order to minimize traffic interference. Real-time traffic and non-real-time traffic have a significant impact on communication performance. We propose a new self-detection traffic interference control technique to improve the Quality of Service (QoS) and throughput of D2D and Cellular-to-Device (C2D) communication in a cellular network, Self-detecting Traffic Interference Control Scheme (STICS). The proposed STICS mechanism distinguishes between short-term traffic congestion process and long-term traffic congestion process according to traffic characteristics to detect and control traffic. When the proposed scheme is applied to the 5G-based cellular network environment, it is expected that the traffic type will be efficiently classified by self-detecting the traffic according to the flow. Such classified traffic is less sensitive to communication between the D2D and C2D links, thereby reducing traffic overload. We evaluate the performance of the proposed scheme through simulation and show that the proposed scheme is more efficient than other comparison schemes.

Wireless sensor networks (WSNs) have gained much attention in today's research domain for supporting a wide variety of applications including the multimedia applications. Multimedia applications that are regarded as the quality-of-service (QoS)-aware, delay sensitive, and bandwidth hungry applications require enough energy and communication resources. WSNs being the energy-scarce network have now been designed in such a way that they can support these delay-sensitive and time-critical applications. In this paper, we propose an energy-efficient routing protocol for heterogeneous WSNs to support the delay sensitive, bandwidth hungry, time-critical, and QoS-aware applications. The proposed QoS-aware and heterogeneously clustered routing (QHCR) protocol not only conserves the energy in the network, but also provides the dedicated paths for the real-time and delay sensitive applications. The inclusion of different energy-levels for the heterogeneous WSNs also provides the stability in the networks while minimizing the delay for the delay-sensitive applications. Extensive simulations have been performed to validate the effectiveness of our proposed scheme. Our proposed routing scheme outperforms other state-of-the-art schemes in terms of the delay performances.

Both economic and environmental costs are driving much research in the area of the energy efficiency of networking equipment. This research has produced a great amount of proposals. However, the majority of them remain unimplemented due to the lack of flexibility of current hardware devices and a certain lack of enthusiasm from commercial vendors. At the same time, Software-Defined Networking (SDN) has allowed customers to control switching decisions with a flexibility and precision previously unheard of. This paper explores the potential convergence between the two aforementioned trends and presents a promising power saving algorithm that can be implemented using standard SDN capabilities of current switches, reducing operation costs on both data centers and wired access networks. In particular, we focus on minimizing the energy consumption in bundles of energy-efficient Ethernet links leveraging SDN. For this, we build on an existing theoretical algorithm and adapt it for implementing with an SDN solution. We study several approaches and compare the resulting algorithms not only according to their energy efficiency, but also taking into account additional QoS metrics. The results show that the resulting algorithm is able to closely match the theoretical results, even when taking into account the requirements of delay-sensitive traffic.

Technological advancement has brought revolutionary change in the converged wireless networks. Due to the existence of different types of traffic, provisioning of Quality of Service (QoS) becomes a challenge in the wireless networks. In case of a congested network, resource allocation has emerged as an effective way to provide the excessive users with desirable QoS. Since QoS for non-real-time traffic are not as strict as for real-time traffic, the unoccupied channels of the adjacent cells can be assigned to the non-real-time traffic to retain QoS for real-time traffic. This results in the intensified bandwidth utilization as well as less interference for the real-time traffic. In this paper, we propose an effective radio resource management scheme that relies on the dynamically assigned bandwidth allocation process. In case of interference management, we classify the traffic into real-time traffic and non-real-time traffic and give priority to the real-time traffic. According to our scheme, the real-time traffic among the excessive number of users are reassigned to the original channels which have been occupied by non-real-time traffic and the non-real-time traffic are allocated to the assigned channels of those real-time traffic. The architecture allows improved signal to interference plus noise ratio (SINR) for real-time traffic along with intensification in the bandwidth utilization of the network. Besides, the increased system capacity and lower outage probability of the network bear the significance of the proposed scheme.

Conference name: IWCMC 2011 - 7th International Wireless Communications and Mobile Computing Conference Date of Conference: 4-8 July 2011 Supporting real-time and quality-of-service (QoS) traffic in multi-hop wireless mobile networks is challenging due to the high level of dynamism involved. In this paper, we propose a network layer solution in the form of a hybrid routing protocol to enable QoS traffic support in this class of networks. Our proposed protocol combines link state topology updates, source routing and on demand link cost dissemination to concurrently support multiple classes of QoS and normal flows. Our protocol provides for QoS traffic by intelligent path selection at the source nodes based on the required QoS parameters/levels and dynamically adapting the paths as network topology and conditions change. This solution does not require any other layers/components in the network stack to be QoS-aware and is therefore readily deployable over existing networks. We present experimental results from a simulation study on the performance of our protocol. Our results show that the proposed solution can provide efficient QoS traffic support in small-to-medium sized mobile networks, where up to 90% improvement in QoS metrics are observed in certain experiments. © 2011 IEEE.

We investigate the problem of joint routing and link scheduling in Time-Division Multiple Access (TDMA) Wireless Mesh Networks (WMNs) carrying real-time traffic. We propose a framework that always computes a feasible solution (i.e. a set of paths and link activations) if there exists one, by optimally solving a mixed integer-nonlinear problem. Such solution can be computed in minutes or tens thereof for e.g. grids of up to 4x4 nodes. We also propose heuristics based on Lagrangian decomposition to compute suboptimal solutions considerably faster and/or for larger WMNs, up to about 50 nodes. We show that the heuristic solutions are near-optimal, and we exploit them to gain insight on the schedulability in WMN, i.e. to investigate the optimal placement of one or more gateways from a delay bound perspective, and to investigate how the schedulability is affected by the transmission range.

Scheduling of real-time uplink flows in HSUPA is hampered by the fact that the NodeB does not know the size and dead-lines of the uplink packets, as the User Equipment (UE) only reports coarse-grained Scheduling Information (SI) advertising the overall backlog. In this paper, we describe how the NodeB can use the sequence of SI to reconstruct a UE queue, using affordable computations. This makes it possible to use scheduling algorithms employing packet sizes and deadlines in HSUPA, with obvious performance benefits. We present a general Virtual Queueing framework, that can be employed with any kind of traffic, and a specialized version of it for periodic (e.g., voice) traffic.

In this paper we investigate link scheduling for Wireless Mesh Networks (WMNs) carrying real-time (i.e., delay-constrained) traffic. We show that the problem of computing a conflict-free link schedule with end-to-end delay constraints can be formulated as a mixed-integer non linear problem that can be optimally solved in reasonable time (i.e., minutes) for relatively large WMNs (up to 20–30 nodes). We use the above result to explore the schedulability region of a WMN with a given routing and input traffic, assessing whether and when aggregating flows which traverse the same path makes a given input flow set sched-ulable. Furthermore, we devise a heuristic solution strategy, which computes good suboptimal solutions within up to few seconds, thus being amenable for online admission control.

International audience; We propose modifications in the TCP-Friendly Rate Control (TFRC) congestion control mechanism from the Datagram Congestion Control Protocol (DCCP) intended for use with real-time traffic, which are aimed at improving its performance for long delay (primarily satellite) links. Firstly, we propose an algorithm to optimise the number of feedback messages per round trip time (RTT) rather than use the currently standard of at least one per RTT, based on the observed link delay. We analyse the improvements achievable with proposed modification in different phases of congestion control and present results from simulations with modified ns-2 DCCP and live experiments using the modified DCCP Linux kernel implementation. We demonstrate that the changes results in improved slow start performance and a reduced data loss compared to standard DCCP, while the introduced overhead remains acceptable.

Automatic repeat request (ARQ) schemes are effective to recover non-real-time data corrupted by channel errors, but their use with real-time traffic is seldom considered because packet retransmissions tend to increase the delay beyond the deadline. However, the high-speed of modern wireless local area networks, together with their inherent low propagation times, favors the use of ARQ schemes with real-time traffic. This paper proposes a fast retransmission scheduling mechanism for reliable transport of real-time traffic in HIPERLAN/2 systems, as well as an adaptive rate scheme designed to reduce the delay introduced by retransmissions while keeping the same level of network efficiency. The achieved performance is evaluated in the scenario of a distributed data acquisition and control system.

Supporting real-time traffic in ad hoc wireless networks is considered as a challenging problem. Existing bandwidth reservation mechanisms assume a TDMA environment where achieving time synchronisation is expensive in terms of resources. Heuristics that exist for slot allocation schemes assume a CDMA over TDMA model in order to alleviate the presence of hidden terminals. Slot allocation strategies in the presence of hidden terminals assume significance in a single channel system for supporting delay sensitive traffic. In this paper, we propose three heuristics for the slot allocation process in asynchronous single channel multihop wireless networks in the presence of hidden terminals. The heuristics we propose are the early fit reservation (EFR), minimum bandwidth-based reservation (MBR) and position-based hybrid reservation (PHR). The EFR heuristic assigns bandwidth link-by-link in the forward path. The MBR heuristic allocates bandwidth to the links in the increasing order of free conn-slots. The PHR heuristic assigns bandwidth for every link proportional to its position in the path. Simulation studies show that EFR performs better in terms of delay characteristics. MBR provides better call blocking performance at the cost of high end-to-end delay. PHR provides a better delay performance compared to MBR and better call blocking performance compared to EFR. Copyright ? 2004 John Wiley & Sons, Ltd.

Characteristics of Mobile Ad hoc Networks such as shared broadcast channel, bandwidth and battery power limitations, highly dynamic topology, and location dependent errors, make provisioning of quality of service (QoS) in such networks very difficult. The Medium Access Control (MAC) layer plays a very important role as far as QoS is concerned. The MAC layer is responsible for selecting the next packet to be transmitted and the timing of its transmission. We have proposed a new MAC layer protocol that includes a laxity-based priority scheduling scheme and an associated back-off scheme, for supporting time-sensitive traffic. In the proposed scheduling scheme, we select the next packet to be transmitted, based on its priority value which takes into consideration the uniform laxity budget of the packet, the current packet delivery ratio of the flow to which the packet belongs, and the packet delivery ratio desired by the user. The back-off mechanism devised by us grants a node access to the channel, based on the rank of its highest priority packet in comparison to other such packets queued at nodes in the neighborhood of the current node. We have studied the performance of our protocol that combines a packet scheduling scheme and a channel access scheme through simulation experiments, and the simulation results show that our protocol exhibits a significant improvement in packet delivery ratio under bounded end-to-end delay requirements, compared to the existing 802.11 DCF and the Distributed Priority Scheduling scheme proposed recently in [ACM Wireless Networks Journal 8 (5) (2002) 455-466; Proceedings of ACM MOBICOM '01, July 2001, pp. 200-209]. ? 2003 Elsevier B.V. All rights reserved.

In all-optical networks where the technique of wavelength division multiplexing is employed, a connection between two nodes is established by first choosing a route connecting these two nodes and then assigning a wavelength to that route. Many connections can share the same physical link, provided that they use different wavelengths. One technology usually employed in order to make more efficient use of the available bandwidth is that of wavelength converters. A converter is placed in some node of the network and has the ability to alter the transmitting wavelength of any incoming signal. In this paper, we study the problem of placing as few converters as possible in a given network so that the number of necessary wavelengths for any routing is equal to the congestion of the network. This problem is known to be $NP$-hard even for bidirected graphs. We give a linear time algorithm for directed graphs of bounded treewidth and an FPT algorithm for arbitrary directed graphs. For undirected graphs we show that the problem is solvable optimally in linear time., TIK Report, 132

Variable bit rate (VBR) video is currently by far the most interesting and challenging real-time application. A VBR encoder attempts to keep the quality of video output constant and at the same time reduces bandwidth requirements, since only a minimum amount of information has to be transferred. On the other hand, as VBR video traffic is both highly variable and delay-sensitive, high-speed networks (e.g. ATM) are generally implemented by assigning peak rate bandwidths to VBR video applications. This approach may, however, be inefficient in a satellite network based on a TDMA scheme. To overcome this problem, we have designed a demand assignment satellite bandwidth allocation algorithm in TDMA, named V2L-DA (VBR 2-Level Demand Assignment), which manages the VBR video traffic according to a dynamic bandwidth allocation algorithm. In this paper we discuss how to tune the proposed algorithm in order to optimize network utilization when MPEG-1 VBR video traffic is being transmitted. Our results indicate that most of the time only 40% of the peak rate bandwidth is needed to satisfy the VBR source, so the remaining 60% of the peak rate bandwidth can be used to transmit the datagram traffic queued in the network stations. © 1997 John Wiley & Sons, Ltd.

We propose asymmetric best-effort, a novel service to provide a "throughput versus delay jitter" differentiated service for IP packets. With this service, every best effort packet is marked as either green or blue. Green packets, typically sent by real-time applications such as interactive audio, receive more losses during bouts of congestion than blue ones. In return, they receive less delay jitter. Both green and blue services are best-effort. The incentive to choose one or other is based on the nature of one's traffic and on traffic conditions. If applications are TCP-friendly, those sending blue packets will receive more throughput but also more delay jitter, than they would if they sent green packets for a given network state and path.

Multimedia applications require the transmission of real-time streams over a network. These streams often exhibit variable bandwidth requirements, and require high bandwidths and guarantees from the network. This creates problems when such streams are delivered over the Internet. To solve these problems, recently, a small set of differentiated services has been introduced. Among these, Premium Service is suitable for transmitting real-time stored stream (full knowledge of the stream characteristics). It uses a bandwidth allocation mechanism (BAM) based on the stream peak rate. Due to the variable bandwidth requirement, the peak rate BAM can waste large amount of bandwidth. In this paper we propose a new BAM that uses less bandwidth than the peak rate BAM, while providing the same service. Our BAM does not affect the real-time stream quality of service (QoS) and does not require any modification to the Premium Service Architecture. We also introduce several frame dropping mechanisms that further reduce bandwidth consumption subject to a QoS constraint when coupled with the above BAM. The proposed BAM and the dropping mechanisms are evaluated using Motion JPEG and MPEG videos and are shown to be effective in reducing bandwidth requirements. Further, since VCR operations are very useful in video streaming, we propose a mechanism that introduces these operations in our BAM. Through simulations we show the effectiveness of this mechanism.

We present the asymmetric best-effort (ABE), a novel service to provide a "throughput versus delay jitter" service for IP packets. With this service, every best effort packet is marked as either green or blue. Green packets, typically sent by real-time applications such as interactive audio, receive more losses during bouts of congestion than blue ones. In return, they-receive a smaller bounded queueing delay. Both green and blue services are best-effort. The incentive to choose one or other is based on the nature of one's traffic and on the traffic conditions. If applications are TCP-friendly, an application sending blue packets will receive more throughput but also more delay jitter, than it would if it sent green packets for a given network state and path. Service provision at each co-operating router can be achieved by packet admission control (PAC) and scheduling. We develop and simulate an initial algorithm that supports this service whose first results show the feasibility of the service.