Showing papers in "Telecommunication Systems in 2014"
TL;DR: The classification presented here summarizes the main features of many published proposals in the literature for efficient routing in MWSN and also gives an insight into the enhancements that can be done to improve the existing routing protocols.
Abstract: The Mobile Wireless Sensor Network (MWSN) is an emerging technology with significant applications. The MWSN allows the sensor nodes to move freely and they are able to communicate with each other without the need for a fixed infrastructure. These networks are capable of out-performing static wireless sensor networks as they tend to increase the network lifetime, reduce the power consumption, provide more channel capacity and perform better targeting. Usually routing process in a mobile network is very complex and it becomes even more complicated in MWSN as the sensor nodes are low power, cost effective mobile devices with minimum resources. Recent research works have led to the design of many efficient routing protocols for MWSN but still there are many unresolved problems like retaining the network connectivity, reducing the energy cost, maintaining adequate sensing coverage etc. This paper addresses the various issues in routing and presents the state of the art routing protocols in MWSN. The routing protocols are categorized based on their network structure, state of information, energy efficiency and mobility. The classification presented here summarizes the main features of many published proposals in the literature for efficient routing in MWSN and also gives an insight into the enhancements that can be done to improve the existing routing protocols.
112 citations
TL;DR: Based on the analysis of flow reliability across a range of networks, the path diversity metric is extended to create a composite compensated total graph diversity metric that is representative of a particular topology’s survivability with respect to distributed simultaneous link and node failures.
Abstract: Path Diversification is a new mechanism that can be used to select multiple paths between a given ingress and egress node pair using a quantified diversity measure to achieve maximum flow reliability. The path diversification mechanism is targeted at the end-to-end layer, but can be applied at any level for which a path discovery service is available. Path diversification also takes into account service requirements for low-latency or maximal reliability in selecting appropriate paths. Using this mechanism will allow future internetworking architectures to exploit naturally rich physical topologies to a far greater extent than is possible with shortest-path routing or equal-cost load balancing. We describe the path diversity metric and its application at various aggregation levels, and apply the path diversification process to 13 real-world network graphs as well as 4 synthetic topologies to asses the gain in flow reliability. Based on the analysis of flow reliability across a range of networks, we then extend our path diversity metric to create a composite compensated total graph diversity metric that is representative of a particular topology's survivability with respect to distributed simultaneous link and node failures. We tune the accuracy of this metric having simulated the performance of each topology under a range of failure severities, and present the results. The topologies used are from national-scale backbone networks with a variety of characteristics, which we characterize using standard graph-theoretic metrics. The end result is a compensated total graph diversity metric that accurately predicts the survivability of a given network topology.
84 citations
TL;DR: The use of a highly available network spine embedded in a physical network together with efficient crosslayer mapping to offer survivability and differentiation of traffic into classes of resilience to provide end-to-end availability guarantees is highlighted.
Abstract: This paper highlights the complexity and challenges of providing reliable services in the evolving communications infrastructure. The hurdles in providing end-to-end availability guarantees are discussed and research problems identified. Avenues for overcoming some of the challenges examined are presented. This includes the use of a highly available network spine embedded in a physical network together with efficient crosslayer mapping to offer survivability and differentiation of traffic into classes of resilience.
68 citations
TL;DR: In this paper, the authors focus on three critical resilience disciplines and the corresponding mechanisms to achieve multilevel resilience: redundancy for fault tolerance, diversity for survivability, and connectivity for disruption tolerance.
Abstract: Communication networks are constructed as a multilevel stack of infrastructure, protocols, and mechanisms: links and nodes, topology, routing paths, interconnected realms (ASs), end-to-end transport, and application interaction. The resilience of each one of these levels provides a foundation for the next level to achieve an overall goal of a resilient, survivable, disruption-tolerant, and dependable Future Internet. This paper concentrates on three critical resilience disciplines and the corresponding mechanisms to achieve multilevel resilience: redundancy for fault tolerance, diversity for survivability, and connectivity for disruption tolerance. Cross-layering and the mechanisms at each level are described, including richly connected topologies, multipath diverse routing, and disruption-tolerant end-to-end transport.
64 citations
TL;DR: This work demonstrates how the modern analog communication system like Community Radio Schemes and Radio Data System (RDS) and digital communication systems such as Simple Digital Video Broadcasting (DVB) and OFDM based data communication can be developed using the Open source hardware USRP1.
Abstract: In this modern world many communication devices are highly intelligent and interconnected between each other. Any up-gradation of the hardware in the existing communication devices is not easier one. Compatibility of the new hardware with existing hardware is highly essential. But the new protocols may or may not support the older one. The solution for these problems can be provided by using the reconfigurable hardware design. The hardware can be reprogrammed according to the new change in technology up-gradation. The cost of commercially available hardware and software requirements for setting up such a module is very high. This can be solved by using Open source hardware and software such as Universal Software Radio Peripheral (USRP) and GNU Radio. This work demonstrates how the modern analog communication system like Community Radio Schemes and Radio Data System (RDS) and digital communication systems such as Simple Digital Video Broadcasting (DVB) and OFDM based data communication can be developed using the Open source hardware USRP1. This work will be helpful even for first year level of engineering students to easily implement any communication and control applications with cheaper cost.
41 citations
TL;DR: A technique to eliminate the sensing-throughput trade-off of the conventional method in the cognitive radio network is investigated and a frame structure is proposed for eliminating such an issue which is presented in the conventional approach.
Abstract: In this paper, we have investigated a technique to eliminate the sensing-throughput trade-off of the conventional method in the cognitive radio network. First, we have discussed the sensing--throughput trade-off caused by the conventional method in the cognitive radio network and then proposes a frame structure for eliminating such an issue which is presented in the conventional approach. However, the proposed method has a drawback, which is solved by the enhancement in the frame structure. We have numerically simulated and compared the throughput of cognitive users for both (conventional and propose) methods. The frame structure enhancement technique decreases the probability of frame collision between the primary and secondary users (SUs) and reduces the data rate loss.
36 citations
TL;DR: This work proposes a protocol to form clusters, select cluster heads, select clusters senders and determine appropriate routings in order to reduce overall energy consumption and enhance the network lifetime.
Abstract: A wireless sensor network is a network of large numbers of sensor nodes, where each sensor node is a tiny device that is equipped with a processing, sensing subsystem and a communication subsystem. The critical issue in wireless sensor networks is how to gather sensed data in an energy-efficient way, so that the network lifetime can be extended. The design of protocols for such wireless sensor networks has to be energy-aware in order to extend the lifetime of the network because it is difficult to recharge sensor node batteries. We propose a protocol to form clusters, select cluster heads, select cluster senders and determine appropriate routings in order to reduce overall energy consumption and enhance the network lifetime. Our clustering protocol is called an Efficient Cluster-Based Communication Protocol (ECOMP) for Wireless Sensor Networks. In ECOMP, each sensor node consumes a small amount of transmitting energy in order to reach the neighbour sensor node in the bidirectional ring, and the cluster heads do not need to receive any sensed data from member nodes. The simulation results show that ECOMP significantly minimises energy consumption of sensor nodes and extends the network lifetime, compared with existing clustering protocol.
31 citations
TL;DR: It is demonstrated that in the K-A-scheme, there is no provision of non-repudiation, it is susceptible to the attack due to a lost smart card, and mutual authentication between the user and the GW-node does not attained.
Abstract: Since wireless sensor networks (WSN) are often deployed in an unattended environment and sensor nodes are equipped with limited computing power modules, user authentication is a critical issue when a user wants to access data from sensor nodes. Recently, M.L. Das proposed a two-factor user authentication scheme in WSN and claimed that his scheme is secure against different kinds of attack. Later, Khan and Alghathbar (K-A) pointed out that Das' scheme has some security pitfalls and showed several improvements to overcome these weaknesses. However, we demonstrate that in the K-A-scheme, there is no provision of non-repudiation, it is susceptible to the attack due to a lost smart card, and mutual authentication between the user and the GW-node does not attained. Moreover, the GW-node cannot prove that the first message comes from the user. To overcome these security weaknesses of the K-A-scheme, we propose security patches and prove our scheme.
30 citations
TL;DR: The design and implementation of SINET4 is described in terms of multiple service provision, network resource control and management, and high reliability from physical level to network management level.
Abstract: The Japanese academic backbone network has been providing a variety of multilayer network services to support a wide range of research and education activities for more than 700 universities and research institutions. The new version, called SINET4, was launched in 2011 in order to enhance the service availability and the network bandwidth as well as to expand the service menu. Its enhanced service availability was unexpectedly verified by the disastrous March 11 Great East Japan Earthquake, when the network managed not to stop service operation even after the earthquake. This paper describes the design and implementation of SINET4 in terms of multiple service provision, network resource control and management, and high reliability from physical level to network management level. The impacts of the huge earthquake are also reported.
22 citations
TL;DR: This paper investigates original point processes that can be used to model the location of transmitters that comply with the CSMA/CA policies and proposes the use of the Simple Sequential Inhibition point process to model CSma/CA networks where clear channel assessment depends on the strongest emitter only.
Abstract: The relative location of simultaneous transmitters, i.e. the set of nodes transmitting a frame at a given time, has a crucial impact on the performance of multi hop wireless networks. Two fundamental aspects of wireless network performances are related to these locations: capacity and interference. Indeed, as interference results from the summation of signals stemmed by concurrent transmitters, it directly depends on the transmitters' location. On the other hand, the network capacity is proportional to the number of simultaneous transmitters. In this paper, we investigate original point processes that can be used to model the location of transmitters that comply with the CSMA/CA policies, i.e. the Medium Access Control protocol used in 802.15.4 and 802.11 families of wireless technologies. We first propose the use of the Simple Sequential Inhibition point process to model CSMA/CA networks where clear channel assessment depends on the strongest emitter only. We then extend this point process to model a busy medium detection based on the strength of all concurrent signals. We finally compare the network capacity obtained through realistic simulations to a theoretical capacity estimated using the intensity of the SSI point process. It turns out that the proposed model is validated by the simulations.
21 citations
TL;DR: Simplicity, low computational cost, self-tuning structure and yet considerable improvement in performance are exclusive features of the proposed AQM for the edge or core routers.
Abstract: When the network suffers from congestion, the core or edge routers signal the incidence of congestion through the active queue management (AQM) to the sources The time-varying nature of the network dynamics and the complex process of retuning the current AQM algorithms for different operating points necessitate the development of a new AQM algorithm Since the non-minimum phase characteristics of the network dynamics restrict direct application of the proportional-integral-derivative (PID) controller, we propose a compensated PID controller based on a new control strategy addressing the phase-lag and restrictions caused by the delay Based on the unstable internal dynamics caused by the non-minimum phase characteristics, a dynamic compensator is designed and a PID controller is then allowed to meet the desired performance objectives by specifying appropriate dynamics for the tracking error Since the controller gains are obtained directly from the dynamic model, the designed controller does not require to be tuned over the system operating envelop Moreover, simulation results using ns2 show improvements over previous works especially when the range of variation of delay and model parameters are drastic Simplicity, low computational cost, self-tuning structure and yet considerable improvement in performance are exclusive features of the proposed AQM for the edge or core routers
TL;DR: This paper presents a novel algorithm that employs a powerful analytic hierarchy process (AHP) methodology to elect clusterheads (CHs) and shows that this scheme is feasible and efficient in preventing blackhole attacks in MANETs.
Abstract: Mobile ad hoc networks (MANETs) become more and more popular and significant in many fields. However, the important applications of MANETs make them very attractive to attackers. The deployment scenarios, the functionality requirements, and the limited capabilities of these types of networks make them vulnerable to a large group of attacks, e.g., blackhole attacks. In this paper, we propose a cluster-based scheme for the purpose of preventing blackhole attacks in MANETs. In our scheme, we firstly present a novel algorithm that employs a powerful analytic hierarchy process (AHP) methodology to elect clusterheads (CHs). Then CHs are required to implement the blackhole attacks prevention scheme to not only detect the existence of blackhole attacks but also identify the blackhole nodes. Simulation results show that our scheme is feasible and efficient in preventing blackhole attacks.
TL;DR: A mobile access solution based on the X-MAC protocol which remains a reference protocol, called MoX-MAC, incorporates different mechanisms that enables to mitigate the energy consumption of mobile sensor nodes.
Abstract: Mobility management in Wireless Sensor Networks (WSNs) is a complex problem that must be taken into account in all layers of the protocol stack. But this mobility becomes very challenging at the MAC level in order to do not degrade the energy efficiency between sensor nodes that are in communication. However, among medium access protocols, sampling protocols reflect better the dynamics of such scenarios. Nevertheless, the main problem, of such protocols, remains the management of collisions and idle listening between nodes. Previous approaches like B-MAC and X-MAC, based on sampling protocols present some shortcomings. Therefore, we address the mobility issue of WSNs that use as medium access sampling protocols.
Firstly, we propose a mobile access solution based on the X-MAC protocol which remains a reference protocol. This protocol, called MoX-MAC, incorporates different mechanisms that enables to mitigate the energy consumption of mobile sensor nodes. Furthermore, we extend our former work (Ba et al. in Proc. of IEEE WMNC, 2011) by evaluating the lifetime of static nodes with respect to MoX-MAC protocol, as well determine the degree of depletion of static nodes due to the presence of mobile nodes.
TL;DR: Numerical results show the superiority of the proposed method over the others in terms of backbone lifetime, end-to-end delay, backbone size, packet delivery ratio, and control message overhead.
Abstract: Due to the highly dynamicity and absence of a fixed infrastructure in wireless mobile ad hoc networks (MANET), formation of a stable virtual backbone through which all the network hosts are connected is of great importance. In this paper, a learning automata-based distributed algorithm is proposed for constructing the most stable virtual backbone of the MANET. To do so, the backbone formation problem is first modeled by the stochastic version of the bounded diameter minimum spanning tree (BDMST) problem. Then, the network backbone is constructed by solving the stochastic BDMST problem for the network topology graph. Several simulation experiments are conducted to investigate the efficiency of the proposed backbone formation protocol. The obtained results are compared with those of the best existing methods. Numerical results show the superiority of the proposed method over the others in terms of backbone lifetime, end-to-end delay, backbone size, packet delivery ratio, and control message overhead.
TL;DR: This system provides a low cost, reliable and robust mobile solution platform with full mobility support for active people that should be under continuous monitoring, and it is ready for use.
Abstract: Monitoring methods for human body parameters are used over years to identify health conditions and biofeedback. For example, the core-body temperature is correlated with women fertility and ovulation periods. Mobile devices offer an extraordinary solution for health monitoring with mobility and continuous monitoring. This paper presents a Windows Mobile based system for body parameters monitoring. The proposed system comprises a SHIMMER-based body sensor network used to measure and collect body parameters, and a mobile application for personal monitoring. The communication between the sensor and the mobile device is performed over a Bluetooth connection. This system provides a low cost, reliable and robust mobile solution platform with full mobility support for active people that should be under continuous monitoring. The system was evaluated and validated, and it is ready for use.
TL;DR: This study considers a fixed-charge relay network design problem whose applications are found mainly in long distance translucent optical telecommunication networks and devise Benders decomposition based solution methodologies in which the algorithmic performance is further enhanced by devising strengthened and disaggregated Benders cuts.
Abstract: In translucent networks, signal regenerators that operate based on optical/electrical/optical (O/E/O) conversion are employed to handle the problems of physical impairments and resulting signal quality issues in long-distance transmissions. Regenerators are placed at the relay nodes in a translucent network in such a way that the optical signals are not transmitted farther than a threshold distance without a 3R regeneration (reamplification-reshaping-retiming).
In this study, we consider a fixed-charge relay network design (FCRND) problem whose applications are found mainly in long distance translucent optical telecommunication networks. From a modeling perspective, FCRND combines prominent features of the uncapacitated single-assignment hub location (location of relays points) and the fixed-charge network design problems (choice of transmission links in the network and routing of signals) while additionally considering distance-based coverage constraints. We devise Benders decomposition based solution methodologies in which the algorithmic performance is further enhanced by devising strengthened and disaggregated Benders cuts, surrogate constraints for the master problem, and an upper bound heuristic to both obtain and tighten optimality Benders cuts. We obtain solutions within 2.0 % of optimality in very reasonable times as we illustrate in our computational study.
TL;DR: This paper proposes and evaluates three detection techniques that improve the ability of selfishness prevention protocols to detect selfish nodes and to increase the number of valid routes.
Abstract: Mobile ad-hoc networks require nodes to cooperate in the relaying of data from source to destination. However, due to their limited resources, selfish nodes may be unwilling to forward packets, which can deteriorate the multi-hop connectivity. Different reputation-based protocols have been proposed to cope with selfishness in mobile ad-hoc networks. These protocols utilize the watchdog detection mechanism to observe the correct relaying of packets, and to compile information about potential selfish nodes. This information is used to prevent the participation of selfish nodes in the establishment of multi-hop routes. Despite its wide use, watchdog tends to overestimate the selfish behavior of nodes due to the effects of radio transmission errors or packet collisions that can be mistaken for intentional packet drops. As a result, the availability of valid multi-hop routes is reduced, and the overall performance deteriorates. This paper proposes and evaluates three detection techniques that improve the ability of selfishness prevention protocols to detect selfish nodes and to increase the number of valid routes.
TL;DR: A secure and selective encryption framework is proposed so as to optimize network lifetime and video distortion for an energy constrained wireless video sensor network (WVSN).
Abstract: The past few years have witnessed increased interest in the potential use of wireless sensor networks (WSNs) in applications such as battlefield assistance, adversary intrusion detection, distributed signal processing, etc. In these applications, multimedia semantic information and video content are extremely sensitive to malicious attacks, including eavesdropping/intercepting of ongoing traffic, and manipulating/counterfeiting of the existing media flows. From a security standpoint, it is very important to transmit authentic and accurate data to surrounding sensor nodes and to the sink. However, securing sensor networks poses unique challenges because these tiny wireless devices are deployed in large numbers, usually in unattended environments, and are severely limited in their capabilities and resources like power, computational capacity, and memory. In this work, a secure and selective encryption framework is proposed so as to optimize network lifetime and video distortion for an energy constrained wireless video sensor network (WVSN).
TL;DR: This paper deals with the problem of generating valid colorings in a distributed way, while minimizing the number of colors used, inspired by the desynchronization observed in the context of the calling behaviour of male Japanese tree frogs.
Abstract: Graph coloring, which is at the heart of several problems arising in wireless ad hoc networks, concerns the problem of assigning colors to the nodes of a graph such that adjacent nodes do not share the same color. This paper deals with the problem of generating valid colorings in a distributed way, while minimizing the number of colors used. Examples of related problems in wireless ad hoc networks are TDMA slot assignment, wakeup scheduling, and data collection. The presented algorithm is inspired by the desynchronization observed in the context of the calling behaviour of male Japanese tree frogs. Experimental results indicate that the proposed algorithm is very competitive with current state-of-the-art approaches.
TL;DR: Results show the performance of the CO-OFDM system at different data rates and distances for one RF carrier and one optical carrier instead of 4 optical carriers used in IEEE 802.3ba.
Abstract: In this paper 40 Gb/s and 100 Gb/s Coherent optical Orthogonal Frequency Division Multiplexing (CO-OFDM) systems are studied to obtain the relation between the bit error rate (BER) and transmission link distance for a constant signal to noise ratio (SNR). Utilizing Dense Wavelength Division Multiplexing (DWDM) with 192 optical channels in C and L bands (1528.77 nm---1612.65 nm), data rates can theoretically reach up to 19 Tb/s (192?100 Gb/s) using only one optical fiber core. In this research, we selected the same data rates with the IEEE standards published by IEEE Computer Society in 2010 and 2011. Results show the performance of the CO-OFDM system at different data rates and distances for one RF carrier and one optical carrier instead of 4 optical carriers used in IEEE 802.3ba.
TL;DR: It is shown that for unpopular TV channels, using unicast flows can be preferable, and the metric of ‘multicast gain’ is introduced as a measure for the bandwidth reduction which can be expected when using multicast (instead of multiple unicast).
Abstract: In applications like IPTV, multicasting provides beneficial services. However, due to overhead and problems of multicast transmission, multicasting is not always profitable. In order to make well-justified decisions whether it is worthwhile to use multicasting or not, its efficiency must be quantified. Therefore, the metric of `multicast gain' is introduced as a measure for the bandwidth reduction which can be expected when using multicast (instead of multiple unicast). Different definitions for multicast gain are given to cover different types of links. As an application of our metric, multicast transmission of live TV channels in WiMAX-based access networks is analyzed. WiMAX as one of the 4G candidates can transmit IPTV services to mobile subscribers because of salient features such as multicast support, wide coverage range and high bandwidth. In OFDMA-based WiMAX the smallest logical bandwidth allocation unit is a slot. In this article, we use the term slot to measure the efficiency of multicasting in WiMAX networks. We show that for unpopular TV channels, using unicast flows can be preferable.
TL;DR: It is shown that the all-terminal reliability of almost every simple graph of order n has a point of inflection, and there are indeed infinite families of graphs (both simple and otherwise) with more than one point ofinflection.
Abstract: Given a finite, undirected graph G (possibly with multiple edges), we assume that the vertices are operational, but the edges are each independently operational with probability p. The (all-terminal) reliability, $\operatorname{Rel}(G,p)$ , of G is the probability that the spanning subgraph of operational edges is connected. It has been conjectured that reliability functions have at most one point of inflection in (0,1). We show that the all-terminal reliability of almost every simple graph of order n has a point of inflection, and there are indeed infinite families of graphs (both simple and otherwise) with more than one point of inflection.
TL;DR: The analytical model models a cell with varying capacity caused by user mobility using a continuous -time Markov chain (CTMC) and shows that using this optimisation algorithm improves the quality of service (QoS) that is experienced by the users.
Abstract: In wireless orthogonal frequency-division multiple access (OFDMA) based networks like Long Term Evolution (LTE) or Worldwide Interoperability for Microwave Access (WiMAX) a technique called adaptive modulation and coding (AMC) is applied. With AMC, different modulation and coding schemes (MCSs) are used to serve different users in order to maximise the throughput and range. The used MCS depends on the quality of the radio link between the base station and the user. Data is sent towards users with a good radio link with a high MCS in order to utilise the radio resources more efficiently while a low MCS is used for users with a bad radio link. Using AMC however has an impact on the cell capacity as the quality of a radio link varies when users move around; this can even lead to situations where the cell capacity drops to a point where there are too little radio resources to serve all users. AMC and the resulting varying cell capacity notably has an influence on admission control (AC). AC is the algorithm that decides whether new sessions are allowed to a cell or not and bases its decisions on, amongst others, the cell capacity. The analytical model that is developed in this paper models a cell with varying capacity caused by user mobility using a continuous -time Markov chain (CTMC). The cell is divided into multiple zones, each corresponding to the area in which data is sent towards users using a certain MCS and transitions of users between these zones are considered. The accuracy of the analytical model is verified by comparing the results obtained with it to results obtained from simulations that model the user mobility more realistically. This comparison shows that the analytical model models the varying cell capacity very accurately; only under extreme conditions differences between the results are noticed.
The developed analytical and simulation models are then used to investigate the effects of a varying cell capacity on AC. Also, an optimisation algorithm that adapts the parameter of the AC algorithm which determines the amount of resources that are reserved in order to mitigate the effects of the varying cell capacity is studied using the models. Updating the parameter of the AC algorithm is done by reacting to certain triggers that indicate good or bad performance and adapt the parameters of the AC algorithm accordingly. Results show that using this optimisation algorithm improves the quality of service (QoS) that is experienced by the users.
TL;DR: An experimental study focused on predictive modeling of the relations between the user perception, user satisfaction and objective technical parameters in data communication services produced a user satisfaction prediction model, which can significantly improve level of user satisfaction with services in telecommunications systems if implemented within advanced system design, optimization and quality assurance procedures.
Abstract: The notion of user perception has grown in terms of its importance and complexity. This paper presents results of an experimental study focused on predictive modeling of the relations between the user perception, user satisfaction and objective technical parameters in data communication services. A new model for prediction of user satisfaction was devised using probability theory based on Markov chain. Two experiments were completed for web browsing scenarios. The results of the first experiment have confirmed that previous user experience has significant effect on the user perception of quality and should represent a vital element of future predictive user models. The result of the second experiment is a user satisfaction prediction model, which presents a novel insight and deeper understanding of user perception of quality. This model can significantly improve level of user satisfaction with services in telecommunications systems if implemented within advanced system design, optimization and quality assurance procedures.
TL;DR: A new link lifetime prediction method for greedy and contention-based routing which can be utilized as a new stability metric is proposed and evaluated by the use of stability-based greedy routing algorithm.
Abstract: Greedy and contention-based forwarding schemes were proposed for mobile ad hoc networks (MANETs) to perform data routing hop-by-hop, without prior discovery of the end-to-end route to the destination. Accordingly, the neighboring node that satisfies specific criteria is selected as the next forwarder of the packet. Both schemes require the nodes participating in the selection process to be within the area that confronts the location of the destination. Therefore, the lifetime of links for such schemes is not only dependent on the transmission range, but also on the location parameters (position, speed and direction) of the sending node and the neighboring node as well as the destination. In this paper, we propose a new link lifetime prediction method for greedy and contention-based routing which can also be utilized as a new stability metric. The evaluation of the proposed method is conducted by the use of stability-based greedy routing algorithm, which selects the next hop node having the highest link stability.
TL;DR: This work proposes a fast-handover for heterogeneous networks that utilizes MIH in PMIPv6 to support heterogeneity networks and to reduce the handover latency time.
Abstract: As the wireless Internet services become widely available, users become able to use various Internet services without restriction in location. In particular, the demands on wireless Internet services are becoming greater, because mobile devices that support high mobility are getting smarter. However, if a user uses various wireless networks, much limitation occurs in network setting when they move a network different each other. This is because there are few appropriate handover mechanisms to support a heterogeneous network. We propose a fast-handover for heterogeneous networks that utilizes MIH in PMIPv6 to support heterogeneous networks and to reduce the handover latency time. And the performance evaluation for the proposed method was done separately for low speed and high speed mobility. The result presented shows that the suggested method has reduced latency time by 26 % and packet losses by 90 % (Avg.).
TL;DR: This paper proposes a multi-agent based homogeneous temporal data aggregation and routing scheme based on fish bone structure of WSN nodes by employing a set of static and mobile agents and observed that the scheme outperforms zonal based aggregation scheme.
Abstract: Wireless sensor networks (WSNs) are constrained by limited node (device) energy, low network bandwidth, high communication overhead and latency. Data aggregation alleviates the constraints of WSN. In this paper, we propose a multi-agent based homogeneous temporal data aggregation and routing scheme based on fish bone structure of WSN nodes by employing a set of static and mobile agents. The primary components of fishbone structure are backbone and ribs connected to both sides of a backbone. A backbone connects a sink node and one of the sensor nodes on the boundary of WSN through intermediate sensor nodes. Our aggregation scheme operates in the following steps. (1) Backbone creation and identifying master centers (or nodes) on it by using a mobile agent based on parameters such as Euclidean distance, residual energy, backbone angle and connectivity. (2) Selection of local centers (or nodes) along the rib of a backbone connecting a master center by using a mobile agent. (3) Local aggregation process at local centers by considering nodes along and besides the rib, and delivering to a connected master center. (4) Master aggregation process along the backbone from boundary sensor node to the sink node by using a mobile agent generated by a boundary sensor node. The mobile agent aggregates data at visited master centers and delivers to the sink node. (5) Maintenance of fish bone structure of WSN nodes. The performance of the scheme is simulated in various WSN scenarios to evaluate the effectiveness of the approach by analyzing the performance parameters such as master center selection time, local center selection time, aggregation time, aggregation ratio, number of local and master centers involved in the aggregation process, number of isolated nodes, network lifetime and aggregation energy. We observed that our scheme outperforms zonal based aggregation scheme.
TL;DR: This article describes a solution that enables limited devices to access contents located in private clouds, as Media Cloud, with the cooperation of network providers.
Abstract: The growing interest in media sharing combined with the explosion of social applications have opened an opportunity window for cloud based applications for media management as Media Cloud, described in this article, that has brought the concept of Cloud Computing to home environments. Media Cloud provides a comprehensive and efficient solution for managing content among federated home environments. As part of the purpose of empowering the user role as well as to improve user experience, we placed significant efforts on interoperability and privacy protection when it comes to accessing cloud resources from other networks. This article describes a solution that enables limited devices to access contents located in private clouds, as Media Cloud, with the cooperation of network providers,
TL;DR: Methods able to maximize the number of demands routed with protection in all-optical way in capacity-constrained networks with limitations on path lengths according to physical impairments are introduced and evaluated.
Abstract: In this paper, we investigate the problem of survivable all-optical routing in WDM networks with physical impairments. One of the recent key issues in survivable optical network design refers to maximization of the ratio of routeable demands while keeping the overall network cost low. In WDM networks, this goal can be achieved by routing as many demands in all-optical way as possible. Based on the latest technical trends driven by deployment costs, technical constraints, and backward compatibility, this will not mean that all demands will be routed in all-optical way in the near future.
Nowadays, operators are mostly willing to dedicate only a given ratio of their power budget to all-optical routing. This in turn implies a new problem to be solved: operators have to find a way to select demands that should be routed in all-optical way and which should not. The problem gets even more complicated, if we add demand protection issues.
In this paper, we introduce and evaluate methods able to maximize the number of demands routed with protection in all-optical way in capacity-constrained networks with limitations on path lengths according to physical impairments.
TL;DR: A novel digital television (DTV) structure that uses RFID for encryption to withstand many attacks that the traditional system is vulnerable to, such as impersonation attack, replay attack and smart card cloning is proposed.
Abstract: As information technology continuously progresses, more applied technologies are developed, such as radio frequency identification (RFID). In this paper, we propose a novel digital television (DTV) structure that uses RFID for encryption. RFID is widely used for various applications because of its advantages such as an extended lifetime and security, and it is less affected by environmental constraints. The proposed protocol uses RFID for encryption to withstand many attacks that the traditional system is vulnerable to, such as impersonation attack, replay attack and smart card cloning. Compared with other protocols, the proposed protocol is more secure and efficient. Thus, our proposed protocol makes the DTV framework more complete and secure.