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Existing works designed for the multi-radio multi-channel (MR-MC) wireless network mainly rely on the orthogonal or non-overlapping channels. But in reality, the limited number of non-overlapping channels is a major issue when the network is dense. In this paper, we study the impact of partially overlapping channels (POC) on the network capacity through computing the maximum achievable capacity in...
Multicast is an important application in cellular networks. The 4G technologies, including WiMAX and LTE, invariably adopt Multiple- Input-Multiple-Output (MIMO) to facilitate spatial multiplexing and fundamentally increase channel capacity. However, state-of-the-art multicast protocols are designed to perform in single-hop mode with a single session, leading to under-utilization of the scarce spectrum...
We consider communication in the uplink of a wireless mesh or sensor network. A group of mobile radios or sensors (hereafter called "nodes") have information to transmit to one or more access points (APs) (or "sinks"). When the channels from the nodes to the APs suffer from fading, direct transmissions to the APs may fail with a high probability, and packets may need to be relayed...
Due to the broadcast nature of wireless transmis- sions, overheard signals can be exploited in multi- hop wireless networks so as to improve the network performance. It has been shown that energy accumulation and information accumulation are two main approaches to utilize multiple overheard signals. However, how to jointly accumulate energy and information in multi-hop wireless networks is still unknown...
We present a framework for automated Medium Access Control (MAC) protocol generation based on a model that incorporates multiple MAC neighborhoods as well as acknowledgments. Both the advertisement and acknowledgment packets are automatically generated by an optimization program that is built based on symbolic Monte Carlo simulation. The design flow chain produces an optimal MAC protocol with respect...
We propose cMAC, a centralized, polling-based protocol for wireless LANs. With cMAC, the access point (AP) sets nodes into the polling mode if they have backlogged data and polls them during the polling period. The AP also periodically opens the contention period to allow nodes with newly arrived data to send data and at the same time announce their queue states. The main feature of cMAC is that it...
Network coding is being viewed to have the potential for significant throughput improvement in network environment. However, these expected benefits are very fragile to malicious attacks, including message block content corruption and node compromise attacks. To solve these problems, both pollution detection and pollution correction based schemes have been proposed. These schemes are only effective...
Cooperative Network-Coded Hybrid ARQ (Coop-NC HARQ) has recently been proposed as a smart way to improve Decode & Forward (D&F) relaying. According to this idea, cooperators send HARQ redundancy on behalf of a source coded together with a data packet intended for the destination they are helping and taken from their own queue. This paper applies for the first time such a technique in ad hoc...
This paper presents a novel Medium Access Control (MAC) protocol for 802.11 networks in which the nodes can adopt smart antenna systems. The presented protocol is designed to satisfy two fundamental requirements: the exploitation of adaptive arrays to increase the network throughput and the backward compatibility of the novel scheme with the 802.11 MAC layer. The developed solution allows the simultaneous...
Relay node (RN) plays a key role in cooperative communications and RN selection may substantially affects the performance gain. In this paper we address the issue of RN selection while taking into account Medium Access Control (MAC) overhead, which is incurred by not only handshake signaling but also frame retransmissions due to transmission error. We use a theoretical model to analyze the cooperation...
One of the major challenges in the medium access control (MAC) protocol design over cognitive Ad Hoc networks (CAHNs) is how to efficiently utilize multiple opportunistic channels, which vary dynamically and are subject to limited power resources. To overcome this challenge, in this paper we first propose a novel diversity technology called Channel-Aggregation Diversity (CAD), allowing each secondary...
This paper analyzes the performance of the Physical Layer Network Coding (PLNC) approach based on Decode-and-Forward (DF) and operating in multipath fading channel. In actual channel affected by multipath fading the DF method has poor performance since the relay node cannot properly perform data decoding. In addition the decoding at the relay requires the knowledge of the channels involved in the...
In this paper, we present a multi-gate mesh network architecture that has been developed to ensure high performance and reliability under emergency conditions when a system expects to receive power outage notifications and exchanges. In order to handle the metering traffic, we introduce a back-pressure based scheduling algorithm, which takes into account both the hop-count, as well as the queue length...
Body-coupled communication (BCC) is a technology that is based on the use of capacitively-coupled electric fields over the human body. In this paper we highlight the design and implementation of a medium access control (MAC) protocol specifically designed to meet the requirements of BCC-enabled body area networks (BANs). We propose a set of specific protocol enhancements over well-known MAC protocols...
Delay/Disruption Tolerant Network (DTN) differs from the conventional networks in that it has no continuous or contemporaneous connections among wireless nodes. Its inherent characteristic of intermittent connections makes existing routing solutions hardly to be applied directly. Epidemic routing using random linear network coding has been studied and proved as an efficient way for light data delivery...
Multipacket reception (MPR) capability provides the opportunity to improve bandwidth utilization while reducing complexity of the medium access control layer. Specifically, it has been shown that ALOHA random access tends to become asymptotically optimal as the receiver's joint decoding capability of the receiver grows to infinity. However, the average traffic offered to the medium is required to...
Opportunistic Network Coding (ONC) has attracted much attention recently. The main improvement of ONC over the traditional network coding is that ONC allows the encoding node to decide whether it employs network coding based on the status of all its input streams. However, due to the nature of fading, wireless links may not always be reliable. Thus, the performance gain of ONC over traditional methods...
Wireless mesh networks (WMNs) are expected to be a next step toward future generation of wireless networks due to their rapidly deployable nature and to the wide variety of their potential use. On the other hand, the daily increase of multimedia applications over wireless networks has generated a vital need to provide Quality of Service (QoS) support in WMNs, and works in this area are not sufficient...
The broadcast nature of wireless links makes wireless networks an attractive environment for intersession network coding. Most intersession network coding protocols exploit this property, but ignore the diversity among the links by turning off coding when the channels are lossy. Other protocols deal with the packets separately - not as members of flows - which makes the intersession network coding...
Social virtual worlds (MMOW) allow users to dynamically create new content with high degree of personalization and immersion in shared real time environments. Popular MMOWs, such as Second Life (SL), are based on a Client/Server (C/S) approach for guaranteeing a shared consistent view of the virtual world, thus generating high network traffic volumes. This is due to the intrinsic features of MMOWs,...
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