The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Network layer indications are not readily available upon a link change; therefore, general dependence on the network layer may introduce unnecessary delays due to network layer signaling for a simple link layer handoff. If information could be gathered at link layer to determine the need for network layer signaling, then both the delay and signaling load could be really improved over current standards...
In this paper we model the data traffic congestion scenario in a vehicular ad-hoc network, and we apply the Adaptive PI Rate Controller (APIRATE) to deal with the congestion. Derived from classical control theory, the APIRATE controller performs AQM (Active Queue Management) by controlling the source rate based on the instantaneous queue length of the congested node. We then study the performance...
Routing protocols for mobile ad hoc networks (MANETs) have been explored extensively in recent years. Among these routing protocols, ad hoc on-demand distance vector (AODV) and dynamic MANET on-demand (DYMO) routing protocols have been standardized by the IETF MANET WG and are the most popular reactive routing protocols for MANETs. Therefore, in this paper, we present the results of the comparison...
In this paper, we consider Mobile WiMAX and LTE as the future technologies for primary OFDMA systems and study dynamic spectrum access (DSA) for unlicensed systems coexisting with primary OFDMA systems. We propose an effective DSA scheme that allows an unlicensed system to statistically and opportunistically access the whole spectrum bandwidth during the last consecutive symbols of each primary OFDMA...
A communication system is developed for ubiquitous - transportation sensor network (u-TSN). The developed system is used for inter-vehicle and vehicle-to-road side unit communications. The communication module is based on the IEEE 802.11a/g standard. The maximum throughput of the communication module is about 10 to 15 Mbps depending on the distance and moving speed.
In this paper, we study about bandwidth and delay estimate in WMAN, and propose a method to obtain different delay estimate in multi-path by transmission detect packets. So that we can estimate any packet's transmission delay in each path. According to delay estimates of the different path, adjust the order of sending of data packet in Cache. So as to achieve the purpose of reducing delays of the...
A mobile ad hoc network eliminates the complexity of infrastructure configuration and allows wireless devices to communicate with each other on the fly. It does not rely on a base station to coordinate the flow of messages in the network. A primary challenge is to provide each device to maintain the information to properly route traffics using a routing protocol and conveying data packets efficiently...
The throughput performance of Mobile Station(MS) in the cell edge is bottle neck for the whole throughput performance of cellular MIMO system. For solving this bottle neck, a base station cooperation (BSC) MIMO technology has been proposed. In addition, in BSC multiuser MIMO (MU-MIMO), the freedom of assigning the wireless channel to user becomes large and thus large user diversity gain can be obtained...
In this paper we propose a mechanism to enable Flexible Spectrum Usage (FSU) in Local Area (LA) indoor deployment scenario of International Mobile Telecommunications-Advanced (IMT-A) with several operators in the given geographical area. The proposed scheme is referred to as policy assisted light Cognitive Radio (CR) enabled FSU, because it follows the CR cycle and considers policy as an important...
To truly realize potential of MANET, multimedia services must be provisioned with a minimum level of QoS. To meet the QoS requirement of such services, many attributes need to be considered. To keep the routing process lightweight, standard QoS aware routing protocol in MANET works with one or two such parameters. In this paper, we have proposed an on-demand source routing protocol for MANET that...
Mobile ad hoc network (MANET) consists of a collection of wireless mobile hosts without the required intervention of any existing infrastructure or centralized access point such as base station. The dynamic topology of MANET allows nodes to join and leave the network at any point of time. Wireless MANET is particularly vulnerable due to its fundamental characteristics such as open medium, dynamic...
In ad hoc mobile networks (MANET), the mobility and traffic patterns for each node are complicated factors that significantly affects the effectiveness and performance of ad hoc routing protocols. In this paper, we focused on the flooding performance of the AODV routing protocol using ns-2 network simulator under different communication distances, and extracted propagation property of RREQ and RREP...
Handover latency is the primary cause of packet loss resulting in performance degradation of the standard Mobile IPv6. Mobile IPv6 with fast Handover enables a Mobile Node (MN) to quickly detect at that IP layer it has moved to a new subnet by receiving link-related information from the link-layer; furthermore it gathers anticipative information about the new Access Point (AP) and the associated subnet...
This paper explores a MAC (Medium Access Control) layer throughput with DCF (Distributed Coordination Function) protocol in the IEEE 802.11a/g-based mobile LAN. It is evaluated in both error-free and error-prone wireless channel with the maximum transmission rate of 54 Mbps, using theoretical analysis method. The DCF saturation throughput performance is analyzed by using the number of stations with...
The concept of byzantine attack comes from byzantine generals problem. In this abstract concept, the loyal byzantine army general are suppose to coordinate in a battlefield to conclude a common plan in the presence of traitor generals which can disrupt such coordination. This generals problem resembles the attacks initiated by authenticated nodes/devices in ad hoc network to disrupt the network. Although...
This paper represents high speed and high throughput pipelined Fast Fourier Transform and its inverse (FFT/IFFT) for Mobile Wi-MAX. Modified architecture also provides concept of local ROM module and variable length support from 128~2048 point for FFT/IFFT. UMC 0.18 ??m is used to design the same. FFT/IFFT chip consumes 266.81 mW at 40 MHz, 130.74 mW at 20 MHz and 65 mW at 10 MHz for length of 2048...
Ad-hoc network is a self organizing and adaptive in nature. Since it is a dynamic multihop wireless network and established by a cluster of mobile nodes on a shared wireless channel. The transitive closure of the neighborhood of all the hosts or nodes in the set of mobiles under consideration forms network. Each node is potentially a router and it is possible to dynamically establish routes by changing...
Route optimization support in mobile networks is one of the most important concerns in Next Generation Networks (NGNs). NGNs require an efficient route optimization scheme, optimized specially to support nesting of mobile networks. We propose an Extended Mobile IPv6 route optimization (EMIP) scheme to enhance the performance of nested mobile networks. EMIP scheme is based on MIPv6 route optimization...
Mobile Ad-hoc Networks (MANETs) are susceptible to both insider and outsider attacks more than wired and base station-based wireless networks. This is because of the lack of a well-defined defense perimeter in MANETs, preventing the use of defenses including firewalls or intrusion detection systems. This lack of perimeter calls for implementation of security in a distributed, collaborative manner...
In this paper, we propose a TDMA based multi-channel MAC protocol to improve the channel efficiency and network performance in wireless ad hoc networks. There are two main problems encountered in all related works in designing multi-channel MAC protocols. The first problem is the rendezvous problem and the second is multi-channel hidden node problem. In order to solve these problems, most of previous...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.