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In Mobile Ad-hoc Networks (MANETs) the wireless nodes move frequently around the space and mutually cooperate with each other to perform routing and forwarding data. MANETs are infrastructure-less networks without any kind of central administration for the management of network. Due to this reason MANETs are comparatively more vulnerable to security threats than conventional wired or wireless networks. The network nodes in MANETs are susceptible a number of attacks due to the inherent nature and depicted properties of MANETs. Thus to prevent attacks it becomes very much mandatory to identify and authenticate each and every node during route discovery phase so that data can be communicated safely later on. In this paper we introduce an authentication mechanism that will enhance the security of standard AODV protocol. The protocol deploys unique prime factorization principle to achieve node authentication with minimal overhead. It detects and isolates unauthorized nodes from the network so as to avoid any kind of attacks from them. [ABSTRACT FROM AUTHOR]

It is widely known that Control Area Networks (CAN) are used in real-time, distributed and parallel processing which cover manufacture plants, humanoid robots, networking fields, etc., In applications where wireless conditions are encountered it is convenient to continue the exchange of CAN frames within the Wireless CAN (WCAN). The WCAN considered in this research is based on wireless token ring protocol (WTRP); a MAC protocol for wireless networks to reduce the number of retransmissions due to collision and the wired counterpart CAN attribute on message based communication. WCAN uses token frame method to provide channel access to the nodes in the system. This method allow all the nodes to share common broadcast channel by taken turns in transmitting upon receiving the token frame which is circulating within the network for specified amount of time. This method provides high throughput in bounded latency environment, consistent and predictable delays and good packet delivery ratio. The most important factor to consider when evaluating a control network is the end-to-end time delay between sensors, controllers, and actuators. The correct operation of a control system depends on the timeliness of the data coming over the network, and thus, a control network should be able to guarantee message delivery within a bounded transmission time. The proposed WCAN is modeled and simulated using QualNet, and its average end to end delay and packet delivery ratio (PDR) are calculated. The parameters boundaries of WCAN are evaluated to guarantee a maximum throughput and a minimum latency time, in the case of wireless communications, precisely WCAN. [ABSTRACT FROM AUTHOR]

Vehicular Adhoc Network (VANET) is the emerging technology which enables the vehicles to communicate using wireless technologies. VANET is developed for providing the safety purpose and driving comfort to the people. VANET use the vehicle as moving nodes as in MANET (Mobile Adhoc Network). The communication among vehicles is done by using the efficient routing protocols which direct the routes. This communication can be direct within the vehicles or it can be between vehicles and road side units (RSUs). In this paper we exploit three routing protocols of VANET which are GPSR, DSDV and BMFR by comparing their three parameters throughput, end to end delay and number of packets dropped during communication. As we study out of this three protocols BMFR and GPSR are position based routing protocol and DSDV is topology based routing. In this paper we also simulate these protocols using NS2 simulator and using the standard protocol i.e. IEEE 802.11 p in Vehicular Adhoc Network. [ABSTRACT FROM AUTHOR]

Mobile ad-hoc networks (MANETs) are fast growing methods of efficient wireless communications in highly mobile environment. Such networks can be designed using software simulators, that allow users to design, test and analyze new solutions at a low cost. These tools enable also an analysis of network configuration and protocol used for optimizing radio resources and performing the best Quality of Service (throughput, delays, etc.). However the simulators cause approximations of results due to simplification of EM compatibility issues and propagation phenomena in the electromagnetic environment. Furthermore the most common simulators do not allow the simulation in a real time, that causes long simulation. This problem can be solved using real time test beds, containing SDR (Software Defined Radio) base solutions. The most popular device based on this technology is USRP (Universal Soft-ware Radio Peripheral), that is widely used by researchers to study various transmission protocols or create real-time applications like OpenBTS or MIMO links. [ABSTRACT FROM AUTHOR]

For establishing communications and modeling a framework for dialogue between intelligent agents, it is beneficial to have a well-defined strategy. In a dialogue run, the strategies are the manners to achieve the agents' goals by selecting the best option between the different existent choices. There are not many works which define the strategies for dialogue between agents. In this paper a formal model for dialogue strategy is proposed. The proposed model is a decision making problem of selecting the type of the act and the compatible content to utter at each step of a dialogue. In a given dialogue step, the model can decide the appropriate act and content allowed by the dialogue protocol in order to satisfy the agents' goals. The strength of the decisions which define the best next move is computed by argumentation theory. The proposed model is illustrated through an example of Dutch auction. [ABSTRACT FROM AUTHOR]

Clock synchronization is a very important issue for the applications of wireless sensor networks. The sensors need to keep a strict clock so that users can know exactly what happens in the monitoring area at the same time. This paper proposes a novel internal distributed clock synchronization solution using group neighborhood average. Each sensor node collects the offset and skew rate of the neighbors. Group averaging of offset and skew rate value are calculated instead of conventional point-to-point averaging method. The sensor node then returns compensated value back to the neighbors. The propagation delay is considered and compensated. The analytical analysis of offset and skew compensation is presented. Simulation results validate the effectiveness of the protocol and reveal that the protocol allows sensor networks to quickly establish a consensus clock and maintain a small deviation from the consensus clock. [ABSTRACT FROM AUTHOR]

This paper analyses the impact of jitter when applied to route discovery in reactive (on-demand) routing protocols. In multi-hop non-synchronized wireless networks, jitter--a small, random variation in the timing of message emission--is commonly employed, as a means to avoid collisions of simultaneous transmissions by adjacent routers over the same channel. In a reactive routing protocol for sensor and ad hoc networks, jitter is recommended during the route discovery process, specifically, during the network-wide flooding of route request messages, in order to avoid collisions. Commonly, a simple uniform jitter is recommended. Alas, this is not without drawbacks: when applying uniform jitter to the route discovery process, an effect called delay inversion is observed. This paper, first, studies and quantifies this delay inversion effect. Second, this paper proposes an adaptive jitter mechanism, designed to alleviate the delay inversion effect and thereby to reduce the route discovery overhead and (ultimately) allow the routing protocol to find more optimal paths, as compared to uniform jitter. This paper presents both analytical and simulation studies, showing that the proposed adaptive jitter can effectively decrease the cost of route discovery and increase the path quality. [ABSTRACT FROM AUTHOR]

In the past, security protocols including key transport protocols are designed with the assumption that there are two parties communication with each other and an adversary tries to intercept this communication. In Delay/Disruption Tolerant Networking (DTN), packet delivery relies on intermediate parties in the communication path to store and forward the packets. DTN security architecture requires that integrity and authentication should be verified at intermediate nodes as well as at end nodes and confidentiality should be maintained for end communicating parties. This requires new security protocols and key management to be defined for DTN as traditional end-to-end security protocols will not work with DTN. To contribute towards solving this problem, we propose a novel Efficient and Scalable Key Transport Scheme (ESKTS) to transport the symmetric key generated at a DTN node to other communicating body securely using public key cryptography and proxy signatures. It is unique effort to design a key transport protocol in compliance with DTN architecture. ESKTS ensures that integrity and authentication is achieved at hop-by-hop level as well as end-to-end level. It also ensures end-to-end confidentiality and freshness for end communicating parties. This scheme provides a secure symmetric key transport mechanism based on public key cryptography to exploit the unique bundle buffering characteristics of DTN to reduce communication and computation cost . [ABSTRACT FROM AUTHOR]

The increasing growth of low-power wireless networks in real-world implementations has intensified the need to develop well-organized key network building blocks. Neighbor discovery, link quality measurement and data collection are among the fundamental building blocks of network initialization process. Over the past decade, network initialization has attracted significant attention from the research community of low-power wireless networks. Accordingly, the general concern of this paper is to survey neighbor discovery, link evaluation and collection tree construction protocols, as well as, research challenges in these research areas. Furthermore, we explore the impacts of these protocols on the functionality of different layers in the network protocol stack. In order to provide a clear view of the state-of-the-art neighbor discovery approaches, this paper also presents a classification of the existing neighbor discovery protocols. Finally, some of the important open issues in developing network initialization protocols are discussed to present new directions for further research. [ABSTRACT FROM AUTHOR]

ABSTRACT Recently, Chen et al. proposed a practical authentication protocol for supporting anonymous roaming in wireless access networks, then the protocol is further improved by Hsieh and Leu. In this paper, we demonstrate the adversarial model of this type of protocols and show that Hsieh-Leu scheme is not as secure as they originally claimed to be. In particular, we show that their protocol does not provide user privacy protection, and it is vulnerable to off-line password guessing attack mounted by a side channel adversary who has compromised all the information stored in the user's smart card. To fix these weaknesses, a new practical authentication protocol with anonymity for wireless roaming is proposed. We use the formal verification tool ProVerif, which is based on applied pi calculus, to prove the security of the proposed scheme. The experimental results confirm that the new scheme not only achieves many desirable properties, such as strong anonymity, perfect forward secrecy and support of session key update, but also provides robustness against all those attacks that Hsieh-Leu protocol does not resist. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this paper, we are interested in improving the performance of TCP flows over wireless networks with a given constructive intersession network coding scheme. We are motivated by the observation that TCP does not fully exploit the potential of the underlying network coding opportunities. In order to improve the performance of TCP flows over coded wireless networks, without introducing changes to TCP itself, we propose a network-coding aware queue management scheme (NCAQM) that is implemented at intermediate network coding nodes and bridges the gap between network coding and TCP rate control. The design of NCAQM is grounded on the network utility maximization (NUM) framework and includes the following mechanisms. NCAQM: 1) stores coded packets at intermediate nodes in order to use the buffer space more efficiently; 2) determines what fraction of the flows should be coded together; and 3) drops packets at intermediate nodes so that it matches the rates of parts of different TCP flows that are coded together. We demonstrate, via simulation, that NCAQM significantly improves TCP throughput compared to TCP over baseline queue management schemes. [ABSTRACT FROM PUBLISHER]

In this article, a Session Initiation Protocol (SIP) overload control solution is proposed. It considers all the types of SIP requests. This is really what a SIP load is composed of, in an industrial environment. So far, the specialized literature considered INVITE messages only. So, we think that SIP servers are required to be dynamically adaptive to the diversity of the incoming load content. In the latter, the rate of a given SIP message type may be more or less than the other message types, depending on the services provided by the SIP server. Sometimes, it also depends on the time of the day. The auto-adaptation ability of the proposed overload control mechanism is designed after the immune system metaphor. The solution is validated through load tests and compared with a well known SIP overload control algorithm. Test load arrival patterns have been chosen to simulate three different service packages known in the SIP industry world as: Hosted Private Branch Exchange, Prepaid Calling Card Service, and Call-Shop Service. [ABSTRACT FROM AUTHOR]

Mobile ad-hoc network has limited battery power. Power consumption control is the main issue in mobile ad-hoc network. Node battery power is a precious resource that should be used in order to avoid the early termination of nodes. Energy management model and power consumption control flow chart is proposed to control power consumption by reducing data transmit time in mobile ad-hoc network. Simulation model has been used to analysis the energy consumption of a node. This has been achieved by estimating the time spent in transmission of data by node. The proposed model has been simulated using OMNET $$++$$ simulator. Simulation results show significant energy savings after applying the proposed model and flow chart. [ABSTRACT FROM AUTHOR]

The commercial success of cellular networks, combined with advances in digital electronics, signal processing, and telecommunications research have lead to the design of next generation 4G-based long term evolution (LTE) wireless systems. The key essence of these emerging, LTE cellular systems lie in deployment of multiple femtocells for improved coverage and higher data rates. However, the arbitrary deployment of a wide number of femtocells makes the configuration, management and planning of LTE systems quite complex and challenging. In order to support dynamic and efficient network configuration, every cell needs to be assigned a particular Physical Cell ID (PCID). In this paper we show that the dynamic, optimal PCID allocation problem in LTE systems is NP-complete. Subsequently we provide a near-optimal solution using Self-Organizing Networks which models the problem using new merge operations and explores the search space using a suitable randomized algorithmic approach. We also discuss two feasible options for dynamic auto-configuration of the system and analyze the algorithm to prove its convergence. Simulation results point out that our proposed near-optimal solution dynamically achieves ∼85−90 % of global optimal auto-configuration in computationally feasible time. [ABSTRACT FROM AUTHOR]

Wireless sensor networks with mobile sinks, mWSNs, have attracted a lot of attention recently. This is because sink mobility can greatly alleviate the hotspot issue in WSNs and further prolong the network lifetime. However, sink mobility also causes unexpected changes in network topology and data routing paths, which can largely affect the routing performance in such networks. Design of efficient routing protocols for mWSNs has been a critical issue, and much work has been carried out in this aspect. In this article, we first classify existing protocols based on different design criteria and then present a survey of the state-of-the-art routing protocols in this area. We illustrate how each of the protocols works, and discuss their advantages and disadvantages. Finally, we point out some future directions for efficient routing in mWSNs. [ABSTRACT FROM AUTHOR]

In this paper, we provide a mathematical framework for the analysis, design, and optimization of network-coded cooperative diversity (NCCD) protocols. The analysis is applicable to relay-aided protocols based on the error propagation model, which rely on appropriately designed diversity-combining demodulators at the destination. Wireless networks with an arbitrary number of sources and relays are considered. Arbitrary multilevel modulation schemes and network codes constructed over a non-binary Galois field (GF) are analyzed. NCCD protocols based on repetition-based and relay selection cooperation are investigated. Two takeaway messages emerge from our analysis: 1) repetition-based NCCD protocols are capable of achieving full-diversity, e.g., if the GF size is sufficiently large and the network code satisfies the maximum distance separable (MDS) property; and 2) NCCD protocols based on relay selection are capable of achieving full-diversity under more restrictive assumptions than repetition-based protocols, e.g., if the number of active relays is no fewer than the number of sources and an MDS network code is used. [ABSTRACT FROM AUTHOR]

We have designed the heterogeneity inclusion and mobility adaptation through locator ID separation (HIMALIS) architecture to support mobility natively in the New Generation Network. This paper proposes a new distributed mobility scheme in the HIMALIS architecture for supporting seamless mobility for the host moving across access networks of different network-layer protocols. The proposed scheme also supports mobility of an access network. It includes a signaling procedure to redirect downstream traffic from the previous gateway (or previous access router) to the new gateway (or new access router) to minimize the service disruption or packet losses during a handover. The performance results obtained from a testbed implementation in Linux validate the effectiveness of the proposal. The results demonstrate that it can achieve seamless (no packet loss) handovers if overlapped wireless access networks are available. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the performance of selecting the best protocol between amplify and forward (AF) and decode and forward (DF) in multiple relay networks with multiple interferences at relays. In the selection scheme, the best protocol between AF and DF is selected depending on the comparisons of signal-to-interference and noise ratio (SINR)for all source-relay links. All relays measure the received SINR to decide whether to forward the signal or not. When SINR is above a certain threshold, then DF is used, otherwise AF is used. Particularly, we develop an accurate mathematical model for best relaying protocol by considering the effect of interferences on our scheme. Firstly, we derive the asymptotic closed form expression for the symbol error rate (SER) of the system under study. Additionally, we derive an upper and lower bound of symbol error rate and show how they were tight with exact SER. Furthermore an approximate expression for the outage probability is derived. Numerical results are finally presented to validate the theoretical analysis with a different number of relays. [ABSTRACT FROM AUTHOR]

Abstract: DCCP (Datagram Congestion Control Protocol) is a transport layer protocol that provides congestion control for unreliable data transmission. The congestion control mechanism embedded in DCCP adjusts the packet sending rate according to network condition. However, DCCP does not discriminate congestion losses and wireless link errors resulted from fading and thus it leads to unnecessary rate adjustment. In this paper, we proposed a mechanism to enhance bandwidth utilization of DCCP over wireless network. We employed a cross-layer loss discrimination scheme to distinguish congestion loss and fading loss. The cross-layer based mechanism detects frame loss in the data link layer in real-time to infer the actual fading loss rate. Thereafter, the fading loss can be excluded from the packet loss observed in the transport layer. Once the accurate congestion loss rate is calculated, the sender can make appropriate adjustment on the transmission rate that reflects the current congestion state along the transmitting path using the DCCP rate control procedure. Simulation results show that DCCP with our proposed CCID 3 rate control scheme can discriminate fading loss and achieve from 4.7% to 15.5% improvement on transmission throughput when the fading loss rate varies from 5% to 15% in wireless network. [Copyright &y& Elsevier]

Abstract: Due to a drastic increase in the number of wireless communication devices, these devices are forced to interfere or interact with each other. This raises the issue of possible effects this coexistence might have on the performance of these networks. Negative effects are a consequence of contention for network resources (such as free wireless communication frequencies) between different devices, which can be avoided if co-located networks cooperate with each other and share the available resources. This paper presents a self-learning, cognitive cooperation approach for heterogeneous co-located networks. Cooperation is performed by activating or deactivating services such as interference avoidance, packet sharing, various MAC protocols, etc. Activation of a cooperative service might have both positive and negative effects on a network’s performance, regarding its high level goals. Such a cooperation approach has to incorporate a reasoning mechanism, centralized or distributed, capable of determining the influence of each symbiotic service on the performance of all the participating sub-networks, taking into consideration their requirements. In this paper, a cooperation method incorporating a machine learning technique, known as the Least Squares Policy Iteration (LSPI), is proposed and discussed as a novel network cooperation paradigm. [Copyright &y& Elsevier]

Cellular networks play a central role in our global networking and communication infrastructure. To ensure and even enhance availability, the standardization process of new communication systems is governed by concerns about reliability, interoperability and security, besides trying to improve the performance of current technology. Still, the ever-increasing demand for higher data-rates forces the consideration of novel research results during standardization. In a heterogeneous network, nodes with different transmission powers and processing capabilities co-exist and user equipments (UEs) can choose to access one or more of the nodes. Long term evolution (LTE) is the next step forward in cellular 3G services. LTE technology is a based on a 3GPP standard that provides for a downlink speed of up to 150 megabits per second (Mbps) and an uplink speed of up to 50 Mbps. Fixed wireless and wired standards are already approaching or achieving 100 Mbps or faster, and LTE is a way for cellular communications to operate at that high data rate. This paper will provides review on LTE net and its architecture and also explain the sleep protocol in LTE. [ABSTRACT FROM AUTHOR]

In recent years' wireless network technology has been widely used in industrial control system. As the bottom foundation of wireless network communication in the industrial control system' Media Access Control (MAC) protocol is the key protocol for efficient wireless network communication. An energy-effective MAC protocol (MEH-MAC) is designed directed at the industrial control system equipped with multi-radio wireless terminal. This new protocol can flexibly configure channel assignments and media access strategies according to different network environments and application requirements' and coordinate the efficient work among multiple radios through the application of MH-RS schedule algorithm. Finally a comparison is made between MEH-MAC and B-MAC to show that MEH-MAC protocol is obviously superior to B-MAC protocol in increasing throughput' reducing transmission delay and decreasing energy consumption. Besides' it has great expansibility and practical value. [ABSTRACT FROM AUTHOR]

This paper introduces a protocol that distributively constructs a collision-free schedule for multi-hop packet radio networks in the presence of hidden terminals. As a preliminary step, each wireless station computes the schedule length after gathering information about the number of flows in its neighbourhood. Then, a combination of deterministic and random backoffs are used to reach a collision-free schedule. A deterministic backoff is used after successful transmissions and a random backoff is used otherwise. It is explained that the short acknowledgement control packets can easily result in channel time fragmentation and, to avoid this, the use of link layer delayed acknowledgements is advocated and implemented. The performance results show that a collision-free protocol easily outperforms a collision-prone protocol such as Aloha. The time that is required for the network to converge to a collision-free schedule is assessed by means of simulation. [ABSTRACT FROM AUTHOR]

Wireless networking protocols are increasingly being designed to exploit a user's measured channel condition; we call such protocols channel-aware. Each user reports the measured channel condition to a manager of wireless resources and a channel-aware protocol uses these reports to determine how resources are allocated to users. In a channel-aware protocol, each user's reported channel condition affects the performance of every other user. The deployment of channel-aware protocols increases the risks posed by false channel-condition feedback. In this paper, we study what happens in the presence of an attacker that falsely reports its channel condition. We perform case studies on channel-aware network protocols to understand how an attack can use false feedback and how much the attack can affect network performance. The results of the case studies show that we need a secure channel condition estimation algorithm to fundamentally defend against the channel-condition misreporting attack. We design such an algorithm and evaluate our algorithm through analysis and simulation. Our evaluation quantifies the effect of our algorithm on system performance as well as the security and the performance of our algorithm. [ABSTRACT FROM PUBLISHER]

In this paper, we consider a two-way relaying network where two users communicate with each other with the help of multiple relays. Specifically, we first investigate the performance of a all-relay participating network with the amplify-and-forward relaying protocol. Based on the moment generating function-based method, we derive some tight bounds for the outage probability and bit-error rate performance. For comparison purpose, we then present a performance analysis for the relay selection scheme. Finally, numerical results are provided to verify our analysis. [ABSTRACT FROM AUTHOR]

Selection cooperation is an attractive cooperative strategy for wireless networks due to its simplicity and efficiency. In this paper, we consider a heterogeneous cooperative network consisting of different kinds of nodes with low-cost radios where the activities of one kind of nodes are triggered by the other kinds of nodes. This is a common scenario for many networks, such as wireless sensor networks. By exploiting the transmission relationship between heterogeneous nodes, we propose a selection cooperation protocol where inducing nodes can cooperate with the following nodes after their own transmissions for improving the communication reliability of the latter nodes. Through performance analysis, we show an interesting feature that the diversity-multiplexing tradeoff of the proposed protocol does not rely on the best relay selection method and the protocol always achieves the full diversity gain. We further develop an energy-efficient best relay selection method based on power control where the power consumption is minimized without decreasing the full diversity order. Simulation results demonstrate the good performance of the protocol and the remarkable energy reduction of the proposed best relay selection method. [ABSTRACT FROM AUTHOR]