Search

The recent boom in wireless communications has led to a wide range of new applications. Wireless positioning is an emerging technology which can provide accurate locations for indoor environments when satellite based positioning systems are not available. In this paper, a Session Initiation Protocol (SIP) based system architecture for wireless positioning is described and an overview of how this can be used in overall system design is provided. New simulation results show that SIP is effective as a network signaling protocol for indoor wireless positioning. [ABSTRACT FROM AUTHOR]

The existence of selfish nodes, who do not cooperate in routing and forwarding, menaces the applicability of mobile ad hoc networks (MANETs). In this paper, we propose a novel price-based method for stimulating cooperation among the nodes of a MANET. This method utilizes the game-theoretic notion of core to distribute the earnings of a cooperation coalition among its members in an optimal manner. In this way, a stable costefficient route is established between communicating parties. [ABSTRACT FROM AUTHOR]

Maintenance of the cache consistency is a complicated issue in the wireless mobile environment. Caching of frequently accessed data items on the node can reduce the bandwidth requirement of the mobile node environment. In this paper, we present a new technique called Modified Energy Efficient Cache Invalidation Algorithm (MEECIA) especially to reduce the uplink bandwidth consumption in the wireless ad-hoc network, by choosing following modes: Slow, Fast, Super-fast. The mode is selected based on threshold specified for time and the number of node requesting the updated data to other node. Simulation results demonstrate that our algorithm is efficient in improving mobile caching, reducing the communication bandwidth and also efficiently utilizing the energy in ad-hoc network. Compared to the previously reported cache based Invalidation Report (IR), our scheme can significantly improve the performance in terms of energy consumption and reduce the query latency in ad-hoc network. [ABSTRACT FROM AUTHOR]

In this paper we propose an approach to improve the performance of existing flood based routing algorithm Ad-hoc on demand Distance Vector Routing [2] for mobile Ad-hoc wireless networks based on heuristic searching technique. Flooding technique is often used for route discovery in on demand mechanism in MANET such as AODV, DSR. To avoid the problem of wireless broadcast storm, the heuristic searching approach was introduced in the process of finding route from source node to destination node. Heuristic function considers the characteristics of MANET (Bandwidth, number of nodes in the given range). If a node S wants to send a packet to D in the flooding method S sends packet to all its neighbor nodes, but in the proposed scheme tries to reduce broadcasting by finding heuristic measures of the neighbors of S. The heuristic measures are evaluated by applying a function to all neighbors. [ABSTRACT FROM AUTHOR]

As wireless networks evolves towards the 3G and 4G architectures the mobile core networks provides a platform for all-IP convergence of mobile and fixed networks allowing for better integration of the Internet and cellular networks, providing better quality of service, charging mechanisms and integration of different services. Due to this convergence, there have been various evidences of interoperability limitations between the mobile and fixed networks such as protocol adaptation, end-to-end Quality of Service (QoS), charging and signalling interworking. Most of these limitations are currently been addressed by respective standards bodies and various proposals are being implemented. In this paper we investigate the signalling limitations across converged networks which are caused by the use of different Session Initiation Protocol (SIP) profiles for signalling in both mobile and fixed networks. We carried out various performance based simulations on the 3GPP proposed solution in which our results reveal critical shortcomings in the solution. We then proposed a new configuration for the system to enable the solution work more efficiently. [ABSTRACT FROM AUTHOR]

Ad hoc networking will become a major technology for wireless connectivity beside the multimedia necessity within the next few years. There are too many applications where one-to-many dissemination is necessary. Most of these applications are characterized by the close collaboration teams with requirements for audio, video conferencing and data sharing which QoS parameters such as bandwidth and delay are very critical for them. In this paper, an efficient algorithm named is proposed to improve the route discovery mechanism in MAODV for QoS multicast routes. QoS-MAODV especially can establish a multicast tree with the minimum required bandwidth support and decrease the end-to-end delay between each destination and the source node. It can establish QoS routes with the reserved bandwidth on per chosen flow. To perform accurate resource reservation, we have developed a method for estimating the consumed bandwidth inmulticast trees by extending the methods proposed for unicast routing. The simulation results show that QoS-MAODV protocol produces higher throughput and lower delay in comparison with MAODV protocol. [ABSTRACT FROM AUTHOR]

Wireless Sensor Networks (WSNs) are spreading around in multiple fields of applications because they perform measuring tasks in a flexible way. This paper presents a survey on nowadays research efforts on the application of these WSNs to the automobile industry, to agriculture, and to wearable technologies (healthcare and athletes monitoring). From our practical deployments, it is important to highlight the functionalities for the automotive industry, and the results extracted from our application to a vineyard. Research on wearable technologies constitutes a challenge, and wireless healthcare solutions in the context of fabrics are being addressed. [ABSTRACT FROM AUTHOR]

This paper presents a novel network design algorithm for Wireless Local Area Networks (WLANs) considering optimal access point placement and frequency channel assignment problems. The proposed algorithm is a cross-layer approach, accounting the physical layer and the data link layer functionalities of the WLANs in the network design process. Specifically, a multi-objective optimization problem is defined. The proposed objective function separates the physical layer considerations and the data link layer contributions in order to differently change the weights of the two characteristics of WLANs. Numerical results are presented and the jointed impact of the physical and the data link layer functionalities on the WLAN quality of services are evaluated. [ABSTRACT FROM AUTHOR]

Spatial query execution is an essential functionality of a sensor network. Redundancy within a sensor network can be exploited to reduce the communication cost incurred in execution of such queries. Any reduction in communication cost would result in an efficient use of battery energy, which is very limited in sensors. One approach to reduce the communication cost of a query is to self-organize the network, in response to a query, into a topology that involves only a small subset of the sensors sufficient to process the query. In this paper, we design an efficient algorithm for the above problem of self-organization of a sensor network into an optimal logical topology, to reduce energy consumption, in response to a query. We introduce the EEDSOSC algorithm, a new Energy Efficient Distributed Selforganization approximation algorithm for Optimal Sensor Cover that produces a near-Optimal Sensor Cover with minimum consumed energy, minimum connected sensor cover and less message communication overhead. The performance of algorithm is tested for both dense and sparse sensor networks. Through extensive simulations, we have shown that our designed technique result in substantial energy savings in a sensor network. Moreover, experiments have been conducted on networks with different sensors transmission radius, different query sizes, and different network configurations. All experimental tests are evaluated using simulations and the experimental results showed that the proposed approach results in a significant communication cost reduction and an energy efficient near-optimal connected sensor cover. Compared with other techniques, the results demonstrated a significant improvement of the proposed technique in terms of energy efficient query cover with lower communication cost. [ABSTRACT FROM AUTHOR]