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Network capacity is a critical feature of wireless ad hoc and sensor networks. It is particularly challenging to determine network capacity when combined with other performance objectives such as timeliness. This paper investigates real-time capacity for event-driven data-gathering sensor networks with the unbalanced many-to-one traffic pattern. First, we compute the average allowable throughputs...
In this abstract, we present Advertisement MAC (ADVMAC), an advertisement based MAC protocol for wireless sensor networks. Simulation results show that ADV-MAC provides a better way to conserve energy and at the same time to support variable traffic loads.
Access points in 802.11 wireless networks suffer from performance problems because of insufficient resources at layer 2 - the DCF (distributed control function) access method provides equal access probability to all devices in a wireless cell including the access point itself. Consequently, performance degrades and contention between uploads and downloads can lead to the familiar TCP unfairness problem...
For solving the issue of congestion in WSN (wireless sensor network), proposed a congestion avoidance and control mechanism for multiple paths routing protocol (MR-CACM), which integrates fairness, status of congestion and level of energy. Consequently the network can avoid congestion by assigning traffic to different paths. When congestion is occurred, it can help to detect congestion by using the...
In this paper, we discuss wireless reduction of quality (RoQ) attacks against the transmission control protocol (TCP). RoQ attacks can dramatically degrade the TCP performance with a less number of wireless jamming attacking packets, which makes them rather difficult to detect. We propose a RoQ attack model which exposes the possibility to launch a RoQ attack and illustrates attack conditions. A CTS...
This paper proposes an adaptive 2 level active period length control method based on traffic load in each cluster for cluster-based wireless sensor networks (WSNs) employing IEEE 802.15.4 medium access control (MAC) protocol. The proposed method consists of two active period length controls: cluster level control and network level control. In the cluster level control, cluster heads autonomously control...
In this paper, we propose a novel coalitional game model for security issues in wireless networks. The model can be applied to not only mobile ad hoc networks but also wireless sensor networks. We define a new throughput characteristic function, on the basis of which nodes are enforced to cooperate and form coalitions. This function implies the maximal throughput and the most reliable traffic that...
In this paper, we investigate and analyze the expected per-node throughput in a wireless sensor network under a randomized sleep scheduling framework with a connectivity constraint. The unique optimal sleep probability maximizing the per-node throughput in the network is found. A sleep probability range in which the throughput monotonically increases along the sleep probability does exist, and it...
IEEE 802.15.4 is one of the most important protocols for wireless sensor networks. To improve the performance of this protocol in consideration of the trade-off between power consumption and end-to-end delay, duty cycle adaptation algorithms are effective solutions. In this paper, we propose an individual beacon order adaptation (IBOA) algorithm for IEEE 802.15.4 networks, which can individually adapt...
In wireless sensor networks (WSNs), timeliness is one of the most challenging problems for critical applications. Caccamo et al. designed a collision-free real-time MAC protocol for sensor networks by adopting the "cellular structure" in traditional telecommunication networks. They assumed that sensors are organized into many rigid hexagon cells and a router node is at the center of each...
Many anonymous communication solutions have been proposed to provide anonymous mobile ad hoc network (MANET) communications. However, they mainly focus on the routing layer and above to hide the end-to-end traffic patterns. The point-to-point communication relations are often considered as non-critical information in terms of anonymity, which actually exposes the traffic patterns on the PHY/MAC layer...
In many reliable Wireless Sensor Network (WSN) applications, messages have different priorities depending on urgency or importance. For example, a message reporting the failure of all nodes in a region is more important than that for a single node. Moreover, traffic can be bursty in nature, such as when a correlated error is reported by multiple nodes running identical code. Current communication...
A new random access system, like ALOHA, is presented in this paper, where each mobile node will either be in a transmitting mode, in a receiving mode or in an idle mode. Results show that the traffic load is independent of the number of nodes, and can be controlled by controlling the transmitting probability, receiving probability and idle mode probability of each mobile node. Certainly, the presented...
In this paper, a slot-based MAC protocol is proposed for cognitive radio wireless networks. This protocol makes cognitive users sense licensed channels periodically, and each period consists of a fixed number of slots. When cognitive users identify un-used licensed channels, they use IEEE 802.11 distribution coordination function (DCF) to contend the spare channels. According to 802.11 DCF, all other...
Ultra-wideband (UWB) is a physical (PHY) layer technology that promises high transmission rates, as well as high resistance to noise and multipath effects. However, the impulse-based nature of UWB, coupled with its low transmission power, makes it difficult to enable efficient detection of the signals. Consequently, conventional carrier-sensing based MAC protocols cannot be used with a UWB PHY. In...
Traffic and channel-data rate combined with the stream oriented methodology can provide a scheme for offering optimized and guaranteed QoS. In this work a stream oriented modeled scheme is proposed based on each nodepsilas self-scheduling energy management. This scheme is taking into account the overall packet loss in order to form the optimal effective -for the end-to-end connection- throughput response...
Different network applications need different Quality of Service (QoS) requirements such as packet delay, packet loss, bandwidth and availability. It is important to develop a network architecture which is able to guaranty quality of service requirements for high priority traffic. In Wireless Multimedia Sensor Networks (WMSNs), a sensor node may have different kinds of sensor which gather different...
In wireless communications networks with multiple service classes (SCs) of calls, call admission control (CAC) schemes is an essential radio resource management (RRM) function for networks consistency. Apart from the calculation of the call blocking probability (CBP) appropriate criteria and metrics should be considered to evaluate the efficiency of various schemes. Fairness among different services...
Wireless sensor network has been widely used in many types of monitoring application in these recent years. For monitoring application such as forest or building monitoring, sensor nodes equipped with temperature sensor, smoke detector and camera will trigger immediately when a fire breaks out. Due to those sensor nodes are transmitting the sensor packets to a sink node at the same time and without...
The efficient use of energy in wireless sensor networks is a critical issue as the sensor nodes typically operate with limited power sources. Most consumption energy of the sensor nodes is used for communication parts. MAC protocols directly control the communications in network; therefore, in this paper we design an innovative contention-based MAC protocol for wireless sensor networks to provide...
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