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.
With the recent development of Device-to-Device (D2D) communication technologies, mobile devices will no longer be treated as pure “terminals”, but they could become an integral part of the network in specific application scenarios. In this paper, we introduce a novel scheme of using D2D communications for enabling data relay services in partial Not-Spots, where a client without local network access...
Routing algorithms for cognitive radio networks should consider various objectives and constraints. Constraint-based routing (CBR) algorithms select a route satisfying constraints that are either administrative-oriented (policy routing), or service-oriented (QoS routing). In cognitive radio networks, a primary user's interference constraint is the most important objective for the activities of secondary...
In this paper, we study the secrecy outage probability (SOP) of an opportunistic relay selection scheme where an optimal relay is selected based on the delayed feedback from the multi-antenna destination. We present a new exact closed-form expression of the SOP, and two kinds of asymptotic form of SOP are further derived to explicitly show secrecy performance. In addition, we show that the SOP can...
In wireless networks, the technique of caching contents cooperatively in user equipments (UEs) and base stations (BSs) enables to improve the performance of data access. In this paper, we consider cluster based cooperative device-to-device (D2D) caching enabled network and formulate the caching problem to minimize content retrieving delay. To achieve this, we develop a content caching and replacement...
In this paper, we propose a relay selection method in an amplify-and-forward (AF) scenario considering complete outdated channel state information (CSI) of all links. Differing from the methods in the literatures considering only outdated CSI over the link from the relay to the destination, another type of outdated CSI, i.e., the outdated CSI over the link from the source to the relay, is also considered...
Network coding (NC) enables us to mix two or more packets into a single coded packet at relay nodes and improve performances in wireless networks. Intra-session sliding window network coding is used at the source nodes and inter-session network coding is employed at the relay node to combine the recovered source packets of source nodes. In this paper, we investigate the performance of the network-coded...
Tactical communication environments are characterized by frequent disruptions, intermittent connectivity, and low bandwidth (DIL) due to the unfavorable, unfriendly, and sometimes very dynamic network conditions. Nevertheless, there is still an expectation that tactical applications can communicate seamlessly despite the challenging communication environment. In this paper, we propose and evaluate...
With the spread of high-performance mobile terminals that include sensors, participatory sensing is attracting attention for collecting sensor information using smartphones. Although there are two key advantages to this approach, its low cost and wide range of sensing, they come at the tradeoff of both the battery and storage. Therefore, efficient collection is required. There is also a challenge...
The entry signal of a Romanian railway station is an installation that allows or forbids the entry of a train in the station. Together with other, interconnected installation, the entry signal insures the railroad traffic safety. Any defect to the signal cause train delays, signal malfunctions may cause railroad traffic events. The diagnosis method proposed in this work comes to the aid of railroad...
In this paper, we propose a framework to analyze the performance of relay-assisted networks. Bursty service, instead of infinite information source, is considered and the arrival process of packets is modeled as a Poisson process. Automatic repeat request (ARQ) protocol is adopted to deal with the transmission errors. Markov chain model is first established based on the node states to investigate...
In this paper, we investigate the joint resource allocation policy for an orthogonal frequency division multiplexing (OFDM)-based cooperative cognitive radio network with statistical delay quality of service (QoS) guarantees. In the CR network, the spectrum leasing scheme operates in a situation where the primary users (PUs) lease part of its licensed spectrum to the secondary users (SUs) in exchange...
Source routing techniques like Trajectory Based Forwarding (TBF) are suitable for dense wireless sensor networks (WSNs) due to their low power requirement. Though usual opportunistic coordination adds reliability to TBF, it also increases delay and coordination complexity. Alternatively, this work proposes the use of multiple cooperative relays within every single hop of a trajectory so that two adjacent...
Delay Tolerant Networks (DTNs) are featured by unpredictable mobility patterns and easily-interrupted connections. Forwarding strategy has always been the research focus, in order to improve the delivery ratio. An enormous amount of researches pay attention to solving the following two problems: whether to forward, and how to forward. Therefore, forwarding metrics and forwarding strategies both play...
The topic-based mobile publish/subscribe (pub/sub) system has shown the potential applications in many scenarios, e.g., product coupon distribution. In this paper, we focus on the budget-constrained data dissemination services with a pre-determinated total amount of copy. A mobile user may subscribe data under different topics, but receiving a copy in any topic is enough. This is the mutually exclusive...
Dual-polarized radar systems rely on coherence between the transmit ports, the receive ports, as well as between transmission and reception. These requirements, however, are not typically met and sustained by low-cost software defined radio (SDR) systems. Phase offsets, in particular, can be introduced by path delays between ports and/or by phase drifts/offsets due to local oscillators. In this work...
In an energy harvesting vehicular network, efficient file transfer between two charging stations is challenging due to the lack of communication infrastructure. Naturally, a source station can allocate the packets to a set of vehicles, which serve as relays to opportunistically deliver these packets to the destination station while performing their own tasks. In this paper, we show that, with packet-level...
Delay Tolerant Network (DTN) comprises of nodes with small and limited resources including power and memory capacity. We propose the use of DTN as an alternate means of communication for the dissemination of emergency information in a post-disaster evacuation operation. We investigate the performance of DTN in providing emergency communication support services under packet dropping attacks. We consider...
We consider a cooperative relaying system with any number of source terminals, one shared relay, and a common destination. We assume a slotted time division multiple access (TDMA) framework in which each source terminal is allocated a fraction of the time. We propose a novel hybrid cooperative scheme for the described network. In contrast to former works which assume that the relay only transmits...
In order to monitor the status and get more data of the electromagnetic launch system in the research of the electromagnetic railgun, many signals need to be controlled and acquired, so the computer measure and control system is an essential part of the electromagnetic launcher. Today's more flexible relays combine traditional protection functions and control logic functions inside a single device...
Implementation of network coding (NC) is expanding to a diverse set of networks due to the flexible design provided through its use, enabling a trade-off between robustness and spectral efficiency. In this paper, we investigate the application of NC in delay tolerant networks (DTN) through the use of software defined radio (SDR) nodes. We specifically focus on a deep space network scenario with large...
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.