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 advent of multimedia applications over wireless local area networks (WLANs), the IEEE 802.11e standard was proposed to incorporate quality of service (QoS) parameters in the medium access control (MAC) layer. It has been found through previous research work that the throughput of transport control protocol (TCP) is less when compared to that of User Datagram Protocol (UDP) in the IEEE 802...
We have recently introduced in the literature MI-MAC (Multimedia Integration Multiple Access Control), a new access control protocol for next generation wireless cellular networks which showed superior performance in comparison to other (TDMA and WCDMA-based) protocols when integrating various types of multimedia traffic. In this work, which to the best of our knowledge is one of the first in the...
This paper presents a study of the dynamic complexity of the Transmission Control Protocol (TCP) over mobile connections in the Universal Mobile Telecommunications System (UMTS) network. Using the concept of time-dependent exponent curves, the dynamic characteristics of TCP are studied and analysed from a simulation model of the UMTS network. Time-dependent exponent graphs have been used to test for...
Wireless growth has been limited by the shortage of radio spectrum. While the spectrum assigned to legacy technologies remain unused, new prominent technologies such as Mesh/WiFi networks are forced to crowd into a small unlicensed band, suffering from significant interference and degraded performance. Using economic incentives, dynamic spectrum auctions redistribute spectrum to make it available...
IEEE P1900.4 is an emerging standard for optimized radio resource utilization where cognitive radio technologies are used for efficient spectrum utilization. In this paper, we design and implement a cognitive wireless network system based on open documents of IEEE P1900.4, and evaluate its performance using UDP streaming and HTTP download. Our experiments show interesting results that total network...
In this paper, we introduce and evaluate ScaleMesh, a scalable miniaturized dual-radio wireless mesh testbed based on IEEE 802.11b/g technology- ScaleMesh can emulate large-scale mesh networks within a miniaturized experimentation area by adaptively shrinking the transmission range of mesh nodes by means of variable signal attenuators. To this end, we derive a theoretical formula for approximating...
This paper presents an ON-OFF-2ON voice traffic model applicable to wireless both-way transmission media. One particularity of voice traffic is that the ON period bursts of packets tend to be independently distributed, while the bursts during a conversation are strongly correlated. This particularity is especially important for WLAN/WMAN resource planning, because the both-ways (transmission and reception)...
In this work, we focus on a WLANs mesh, i.e., an ad hoc, IEEE 802.11-based network whose nodes are either user devices or access points providing access to the mesh network or to the Internet. By relying on some work about IEEE 802.11 MAC analysis, we consider mesh-DQDC protocol and present an analytical model of the MAC scheme, through which we show that the protocol achieves high throughput both...
Following the huge commercial success of WLAN, multihop wireless networks are expected to lead in the next wave of deployment. Fundamental methods for traffic engineering must be developed to support diverse application requirements in these networks. This paper studies the problem of how to support weighted bandwidth allocation among all end-to-end flows in a multihop wireless network. Our goal is...
This paper presents a mechanism to evaluate fault-tolerant WiFi network performance in a mobile environment. Fault-tolerance at the access point (AP) level is presented in a degraded performance mode. In case of an access point (AP) failure the surrounding APs increase their power to compensate for this failure. Mobile IPv6 is used as mobile protocol for the moving entities. A new metric is introduced...
This paper proposes an extension to Fast-handover Mobile IPv6 [6] that improves handover latency in Mobile IPv6 procedures in case mobile nodes have multiple wireless interfaces. In the basic Fast MIPv6 [6], a previous access router (PAR) forwards arriving packets for the mobile node to a new access router (NAR) by setting up a tunnel to the NAR in order to prevent packet losses incurred by latency...
Code updates, such as those for debugging purposes, are frequent and expensive in the early development stages of wireless sensor network applications. We propose AdapCode, a reliable data dissemination protocol that uses adaptive network coding to reduce broadcast traffic in the process of code updates. Packets on every node are coded by linear combination and decoded by Gaussian elimination. The...
A new and simple MAC protocol is proposed. Each node transmits a burst with length sampled from a geometric distribution with parameter q followed by a carrier sense slot. A node repeats the previous operations until it senses a busy slot. A node will access the channel and transmit its payload when it has sensed h idle slots. The parameter q can be adjusted for each node to achieve desired levels...
In this paper, we perform an extensive measurement study on a multi-tier mesh network serving 4,000 users. Such dense mesh deployments have high levels of interaction across heterogeneous wireless links. We find that this heterogeneous backhaul consisting of data-carrying (forwarding) links and non- data-carrying (non-forwarding) links creates two key effects on performance. First, we show that low-rate...
Significant progress has been made in understanding the behavior of TCP and congestion-controlled traffic over multi- hop wireless networks. Despite these advances, however, no prior work identified severe throughput imbalances in the basic scenario of mesh networks, in which one-hop flows contend with two-hop flows for gateway access. In this paper, we demonstrate via real network measurements, test-bed...
Knowledge of the error process and related channel parameters in wireless networks is invaluable and highly instrumental in a broad range of applications. Under the IEEE 802.15.4 Low Rate-Wireless Personal Area Networks (LR- WPAN) standard, compliant devices are capable of providing two pieces of information about the channel conditions along with each received packet, the Link Quality Indication...
In this paper we study the problem of jointly performing scheduling and congestion control in mobile ad-hoc networks so that network queues remain bounded and the resulting flow rates satisfy an associated network utility maximization problem. In recent years a number of papers have presented theoretical solutions to this problem that are based on combining differential-backlog scheduling algorithms...
A major barrier for the adoption of wireless mesh networks is severe limits on throughput. Many in-network packet mixing techniques at the network layer [1], [2], [3] as well as the physical layer [4], [5], [6] have been shown to substantially improve throughput. However, the optimal mixing algorithm that maximizes throughput is still unknown. In this paper, we propose iPack, an algorithm for in-network...
The overlay-based network architecture has been recognized as an effective way to deal with the funneling effect in sensor networks, where sensors closer to the sink are usually responsible for relaying more network traffic. Such funneling effect is particularly harmful when the number of sensors in the network is vast. In an overlay-based sensor network, a special type of resource-rich multi-radio...
Many wireless network standards include quality-of-service (QoS) features at the MAC layer. These features provide nodes transmitting high priority delay sensitive traffic such as voice and video preferential access to the channel over nodes carrying low priority delay tolerant traffic such as file transfer and email. However, such schemes are unfair to low priority users, depriving them of equitable...
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.