Anlytical study based on issues of Routing & Security in Wireless sensor networks

Wireless Sensor Networks (WSN) are receiving significant importance in the present scenario owing to their unlimited potential and world wide applications. The routes in the network are determined by the most secured and energy efficient routing protocols and these energy efficient routing protocols employed for WSNs are the Hierarchical or cluster based routing protocols that are essential for path computation in sensor networks. Since most of the hierarchical routing protocols aim to be developed as energy efficient, the security issues are not given much importance most of the times. But in certain applications such as military or battle field the data is to be maintained secret while communicating between sensor nodes and basin so security issues are also required to be focused in developing routing protocols. Keeping in view above in this paper we intend to present the various security issues involved while designing the hierarchical routing protocol for a specific WSN and the design challenges while studying different hierarchical based routing protocols. Keywords- Wireless Sensor Networks (WSNs), Hierarchical routing, Securityissues

Non-minimal adaptive routing for efficient interconnection networks

RESUMEN: La red de interconexión es un concepto clave de los sistemas de computación paralelos. El primer aspecto que define una red de interconexión es su topología. Habitualmente, las redes escalables y eficientes en términos de coste y consumo energético tienen bajo diámetro y se basan en topologías que encaran el límite de Moore y en las que no hay diversidad de caminos mínimos. Una vez definida la topología, quedando implícitamente definidos los límites de rendimiento de la red, es necesario diseñar un algoritmo de enrutamiento que se acerque lo máximo posible a esos límites y debido a la ausencia de caminos mínimos, este además debe explotar los caminos no mínimos cuando el tráfico es adverso. Estos algoritmos de enrutamiento habitualmente seleccionan entre rutas mínimas y no mínimas en base a las condiciones de la red. Las rutas no mínimas habitualmente se basan en el algoritmo de balanceo de carga propuesto por Valiant, esto implica que doblan la longitud de las rutas mínimas y por lo tanto, la latencia soportada por los paquetes se incrementa. En cuanto a la tecnología, desde su introducción en entornos HPC a principios de los años 2000, Ethernet ha sido usado en un porcentaje representativo de los sistemas. Esta tesis introduce una implementación realista y competitiva de una red escalable y sin pérdidas basada en dispositivos de red Ethernet commodity, considerando topologías de bajo diámetro y bajo consumo energético y logrando un ahorro energético de hasta un 54%. Además, propone un enrutamiento sobre la citada arquitectura, en adelante QCN-Switch, el cual selecciona entre rutas mínimas y no mínimas basado en notificaciones de congestión explícitas. Una vez implementada la decisión de enrutar siguiendo rutas no mínimas, se introduce un enrutamiento adaptativo en fuente capaz de adaptar el número de saltos en las rutas no mínimas. Este enrutamiento, en adelante ACOR, es agnóstico de la topología y mejora la latencia en hasta un 28%. Finalmente, se introduce un enrutamiento dependiente de la topología, en adelante LIAN, que optimiza el número de saltos de las rutas no mínimas basado en las condiciones de la red. Los resultados de su evaluación muestran que obtiene una latencia cuasi óptima y mejora el rendimiento de algoritmos de enrutamiento actuales reduciendo la latencia en hasta un 30% y obteniendo un rendimiento estable y equitativo.ABSTRACT: Interconnection network is a key concept of any parallel computing system. The first aspect to define an interconnection network is its topology. Typically, power and cost-efficient scalable networks with low diameter rely on topologies that approach the Moore bound in which there is no minimal path diversity. Once the topology is defined, the performance bounds of the network are determined consequently, so a suitable routing algorithm should be designed to accomplish as much as possible of those limits and, due to the lack of minimal path diversity, it must exploit non-minimal paths when the traffic pattern is adversarial. These routing algorithms usually select between minimal and non-minimal paths based on the network conditions, where the non-minimal paths are built according to Valiant load-balancing algorithm. This implies that these paths double the length of minimal ones and then the latency supported by packets increases. Regarding the technology, from its introduction in HPC systems in the early 2000s, Ethernet has been used in a significant fraction of the systems. This dissertation introduces a realistic and competitive implementation of a scalable lossless Ethernet network for HPC environments considering low-diameter and low-power topologies. This allows for up to 54% power savings. Furthermore, it proposes a routing upon the cited architecture, hereon QCN-Switch, which selects between minimal and non-minimal paths per packet based on explicit congestion notifications instead of credits. Once the miss-routing decision is implemented, it introduces two mechanisms regarding the selection of the intermediate switch to develop a source adaptive routing algorithm capable of adapting the number of hops in the non-minimal paths. This routing, hereon ACOR, is topology-agnostic and improves average latency in all cases up to 28%. Finally, a topology-dependent routing, hereon LIAN, is introduced to optimize the number of hops in the non-minimal paths based on the network live conditions. Evaluations show that LIAN obtains almost-optimal latency and outperforms state-of-the-art adaptive routing algorithms, reducing latency by up to 30.0% and providing stable throughput and fairness.This work has been supported by the Spanish Ministry of Education, Culture and Sports under grant FPU14/02253, the Spanish Ministry of Economy, Industry and Competitiveness under contracts TIN2010-21291-C02-02, TIN2013-46957-C2-2-P, and TIN2013-46957-C2-2-P (AEI/FEDER, UE), the Spanish Research Agency under contract PID2019-105660RBC22/AEI/10.13039/501100011033, the European Union under agreements FP7-ICT-2011- 7-288777 (Mont-Blanc 1) and FP7-ICT-2013-10-610402 (Mont-Blanc 2), the University of Cantabria under project PAR.30.P072.64004, and by the European HiPEAC Network of Excellence through an internship grant supported by the European Union’s Horizon 2020 research and innovation program under grant agreement No. H2020-ICT-2015-687689

Minimal deployable endpoint-driven network forwarding: principle, designs and applications

Networked systems now have significant impact on human lives: the Internet, connecting the world globally, is the foundation of our information age, the data centers, running hundreds of thousands of servers, drive the era of cloud computing, and even the Tor project, a networked system providing online anonymity, now serves millions of daily users. Guided by the end-to-end principle, many computer networks have been designed with a simple and flexible core offering general data transfer service, whereas the bulk of the application-level functionalities have been implemented on endpoints that are attached to the edge of the network. Although the end-to-end design principle gives these networked systems tremendous success, a number of new requirements have emerged for computer networks and their running applications, including untrustworthy of endpoints, privacy requirement of endpoints, more demanding applications, the rise of third-party Intermediaries and the asymmetric capability of endpoints and so on. These emerging requirements have created various challenges in different networked systems. To address these challenges, there are no obvious solutions without adding in-network functions to the network core. However, no design principle has ever been proposed for guiding the implementation of in-network functions. In this thesis, We propose the first such principle and apply this principle to propose four designs in three different networked systems to address four separate challenges. We demonstrate through detailed implementation and extensive evaluations that the proposed principle can live in harmony with the end-to-end principle, and a combination of the two principle offers more complete, effective and accurate guides for innovating the modern computer networks and their applications.Ope

Real-Time Routing Protocols for Wireless Sensor Networks

International audienceDeveloping real-time routing protocols under energy constraint is one of the key points for providing end-to-end delay guarantee in multi-hop wireless sensor networks. In this paper, we give, at first, an overview of the existing real-time routing protocols and point out some potential approaches to improve them. To enhance existing protocols, one way is to make routing decision based on multi-hop rather than 1-hop neighborhood information. We study the asymptotic performance of a generic routing metric as the quantity of information a priori increases and propose then a 2-hop neighborhood information based real-time routing protocol. As an example, the approach of mapping packet deadline to a velocity is adopted as in SPEED; however, our routing decision is made based on the 2-hop velocity. An energy efficient probabilistic drop is proposed to improve energy utilization efficiency. When packet deadline requirement is not stringent, a design is integrated to release nodes from heavy consumption. Energy balance over nodes is thus improved. Simulation results show that, compared with protocol SPEED that only utilizes 1-hop information, the proposed scheme leads to lower deadline miss ratio and higher energy efficiency

Secure location-aware communications in energy-constrained wireless networks

Wireless ad hoc network has enabled a variety of exciting civilian, industrial and military applications over the past few years. Among the many types of wireless ad hoc networks, Wireless Sensor Networks (WSNs) has gained popularity because of the technology development for manufacturing low-cost, low-power, multi-functional motes. Compared with traditional wireless network, location-aware communication is a very common communication pattern and is required by many applications in WSNs. For instance, in the geographical routing protocol, a sensor needs to know its own and its neighbors\u27 locations to forward a packet properly to the next hop. The application-aware communications are vulnerable to many malicious attacks, ranging from passive eavesdropping to active spoofing, jamming, replaying, etc. Although research efforts have been devoted to secure communications in general, the properties of energy-constrained networks pose new technical challenges: First, the communicating nodes in the network are always unattended for long periods without physical maintenance, which makes their energy a premier resource. Second, the wireless devices usually have very limited hardware resources such as memory, computation capacity and communication range. Third, the number of nodes can be potentially of very high magnitude. Therefore, it is infeasible to utilize existing secure algorithms designed for conventional wireless networks, and innovative mechanisms should be designed in a way that can conserve power consumption, use inexpensive hardware and lightweight protocols, and accommodate with the scalability of the network. In this research, we aim at constructing a secure location-aware communication system for energy-constrained wireless network, and we take wireless sensor network as a concrete research scenario. Particularly, we identify three important problems as our research targets: (1) providing correct location estimations for sensors in presence of wormhole attacks and pollution attacks, (2) detecting location anomalies according to the application-specific requirements of the verification accuracy, and (3) preventing information leakage to eavesdroppers when using network coding for multicasting location information. Our contributions of the research are as follows: First, we propose two schemes to improve the availability and accuracy of location information of nodes. Then, we study monitoring and detection techniques and propose three lightweight schemes to detect location anomalies. Finally, we propose two network coding schemes which can effectively prevent information leakage to eavesdroppers. Simulation results demonstrate the effectiveness of our schemes in enhancing security of the system. Compared to previous works, our schemes are more lightweight in terms of hardware cost, computation overhead and communication consumptions, and thus are suitable for energy-constrained wireless networks

Position-Based Multicast for Mobile Ad-hoc Networks

In general, routing protocols for mobile ad-hoc networks (MANETs) can be classified into topology-based protocols and position-based protocols. While for unicast routing many proposals for both classes exist, the existing approaches to multicast routing basically implement topology-based algorithms and only a few of them make use of the geographic positions of the network nodes. These have in common that the sending node has to precalculate the multicast tree over which the packets are distributed and store it in each packet header. This involves two main issues: (a) These approaches are not very flexible with regard to topological changes which abandons the advantages that position-based routing has against topology-based routing, and (b) they do not scale with the number of receivers, since every one of them has to be named in the packet header. This thesis solves these issues and further advances position-based multicast routing. Position-Based Multicast (PBM) enhances the flexibility of position-based multicast routing by following the forwarding principle of position-based unicast routing. It transfers the choice of the next hops in the tree from the sender to the forwarding nodes. Based on the positions of their neighboring nodes, these are able to determine the most suitable next hop(s) at the moment when the packet is being forwarded. The scalability with respect to the number of receiving nodes in a group is solved by Scalable Position-Based Multicast (SPBM). It includes a membership management fulfilling different tasks at once. First, it administers group memberships in order to provide multicast sources with information on whether nodes are subscribed to a specific group. Second, it implements a location service providing the multicast sources with the positions of the subscribed receiver nodes. And third, it geographically aggregates membership data in order to achieve the desired scalability. The group management features two modes of operation: The proactive variant produces a bounded overhead scaling well with the size of the network. The reactive alternative, in contrast, reaches low worst-case join delays but does not limit the overhead. Contention-Based Multicast Forwarding (CBMF) addresses the problems that appear in highly mobile networks induced by outdated position information. Instead of basing forwarding decisions on a perception that may no longer be up to date, the packets are addressed only to the final destination; no explicit next hops are specified. The receiving nodes, which are candidate next hops, then decide by means of contention which of them are the most suitable next hop(s) for a packet. Not only is the decision made based on the most currently available data, but this procedure also saves the regular sending of beacon messages, thus reducing the overhead. The lack of multicast congestion control is another unsolved problem obstructing high-bandwidth data transmission. Sending out more and more packets to a multicast group lets the performance decrease. Backpressure Multicast Congestion Control (BMCC) takes care that the network does not need to handle more packets than it is able to. It achieves this by limiting the packet queues on the intermediate hops. A forwarder may not forward the next packet of a stream before it has noticed---by overhearing the transmission of the next hop---that the previous packet has succeeded. If there is congestion in an area, backpressure is implicitly built up towards the source, which then stops sending out packets until the congestion is released. BMCC takes care that every receiving node will receive packets at the same rate. An alternative mode of operation, BMCC with Backpressure Pruning (BMCC-BP) allows the cutting of congested branches for single packets, permitting a higher rate for uncongested receivers. Besides presenting protocols for multicast communication in MANETs, this thesis also describes implementations of two of the above-mentioned protocols. The first one is an implementation of SPBM for the Linux kernel that allows IP applications to send data via UDP to a group of receivers in an ad-hoc network. The implementation resides between the MAC layer and the network/IP layer of the network stack. It is compatible with unmodified standard kernels of versions 2.4 and 2.6, and may be compiled for x86 or ARM processor architectures. The second implementation is an implementation of CBMF for the ScatterWeb MSB430 sensor nodes. Due to their low-level programmability they allow an integration of the routing protocol with the medium access control. The absence of periodic beacon messages makes the protocol especially suitable for energy-constrained sensor networks. Furthermore, other constraints like limited memory and computational power demand special consideration as well

On the Complexity of Compressing Two Dimensional Routing Tables with Order

International audienceMotivated by routing in telecommunication network using Software Defined Network (SDN) technologies, we consider the following problem of finding short routing lists using aggregation rules. We are given a set of communications X , which are distinct pairs (s, t) ⊆ S × T , (typically S is the set of sources and T the set of destinations), and a port function π : X → P where P is the set of ports. A routing list R is an ordered list of triples which are of the form (s, t, p), If r(s, t) = π(s, t), then we say that (s, t) is properly routed by R and if all communications of X are properly routed, we say that R emulates (X , π). The aim is to find a shortest routing list emulating (X , π). In this paper, we carry out a study of the complexity of the two dual decision problems associated to it. Given a set of communication X , a port function π and an integer k, the A preliminary short version of this work has appeared in [7]. 2 Frédéric Giroire et al. first one called Routing List (resp. the second one, called List Reduction) consists in deciding whether there is a routing list emulating (X , π) of size at most k (resp. |X | − k). We prove that both problems are NP-complete. We then give a 3-approximation for List Reduction, which can be generalized to higher dimensions. We also give a 4-approximation for Routing List in the fundamental case when there are only two ports (i.e. |P | = 2), X = S × T and |S| = |T |