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.
For wireless VoD (Video on Demand) service, in order to improve spectrum efficiency and provide users good QoS (quality of service), this paper proposes a new bandwidth allocation algorithm based on periodic broadcasting and FGS (fine-granular-scalability) video coding schemes. Different from existing bandwidth allocation algorithms, this paper refinedly takes into account the heterogeneity of users...
Wireless communications over water may suffer from serious multipath fading due to strong specular reflections from conducting water surfaces. Cognitive radios enable dynamic spectrum access over a large frequency range, which can be used to mitigate this problem. In this paper, we study how to leverage cognitive radios for effective communications in wireless networks over water. We formally define...
Call Admission Control (CAC) schemes based on guard channel are widely used to protect handoff calls for seamless wireless services. In this paper, we propose a guard channel based CAC scheme where new calls arrive in batches. A fixed number of guard channels are reserved for handoff calls. The main objective of our proposed scheme is to alleviate the new call blocking probability due to guard channels...
This paper presents a new method to estimate the available bandwidth and the path capacity over a wireless network path, denoted as rt-Winf. The estimation is performed in real-time and without the need to intrusively inject packets in the network. This is accomplished by resorting to the CSMA-CA scheme with RTS/CTS packets to determine each node's channel allocation. rt-Winf repeatedly samples the...
Multicast support is critical and a desirable feature of multi-radio wireless mesh networks. However, the nature of wireless network, i.e. broadcasting and interference, makes it a challenge to efficiently support multicast services. In this paper, we study how to build a multicast structure with maximum average throughput in terms of minimum transmission time and channel interference in a multi-radio...
In this paper, channel allocation scheme is studied for overlay wireless networks to optimize connection-level QoS. The contributions of our work are threefold. First, channel allocation scheme using both horizontal channel borrowing and vertical channel borrowing is presented and analyzed. Channel borrowing is restricted within handoff requests, and only predefined channels can be lent. When all...
Wireless networks are characterized by having limited resources accessed by a large number of mobile stations with distinct capabilities. In such challenged environment the dynamic control of resources is of major importance to mitigate the limitations of wireless networks, such as the impact of low data rate stations and wireless channel oscillations. Such augmented usage of wireless resources can...
Efficient resource allocation is a critical component in multi-user QoS communications and high speed networks. In this paper, we devise a new mathematical model for the resource allocation problem that takes into account the users' demands in a PHY-MAC cross-layer approach. Incorporating the time axis in our model, the target is to maximize the number of bits transmitted in a given frame rather than...
Multi-channel wireless networks are increasingly being employed as infrastructure networks in metro areas. In addition, nodes in these networks employ directional antennas to improve spatial throughput. In such networks, we consider the problem of finding a broadcast tree from a given root with channel assignment such that all the links in the broadcast tree can be active simultaneously without interfering...
Channel assignment is the key problem in the research of the multi-radio multi-channel wireless mesh networks (WMN). In this paper we propose a new loop-based mechanism for dynamic distributed Channel Assignment (DCA) in WMN. The group which we called Grid-loop is constructed on distributed Minimum Spanning Tree by self-organized. Our new DCA mechanism has many advantages over cluster-based. The analysis...
Channel assignment has become a very important research area nowadays. In this paper, we study the existence of Nash Equilibria of selfish channel assignment in Aloha-type multi-channel multi-radio (MCMR) wireless networks. Our analysis shows that selfishness leads to balanced channel assignment in a single collision domain, while usually unbalanced solutions in multiple collision domains. We also...
The allocation of communication power consumption and computing rate is inherently one of the cross-layer problems in wireless distributed computing networks (WDCNs). This paper exploits a subgradient approach to choose the optimal power-rate pair for maximizing the network computing capability and minimizing the power consumption. The impact of heterogeneous channel conditions for different nodes...
This paper studies the problem of multicast routing and channel assignment in multi-channel and multi-interface wireless mesh networks. The advantage of the wireless broadcast's nature is used to reduce interference and improve network throughput. The employed network model is first described. Next, a heuristic channel assignment algorithm that makes use of the wireless broadcast's advantage is presented...
Wireless mesh networking is a promising, cost effective and efficient technology for realizing backhaul networks supporting high quality services. In such networks, multicast data are transmitted blindly without any mechanism protecting data from loss, ensuring data reception, and optimizing channel allocation. The multicast services may undergo, then, very high data loss ratio which is exacerbated...
Spectrum access scheme is a fundamental component in building efficient wireless networks. Conventional methods such as proactive channel assignment is costly due to large amount of protocol overhead. Also, those algorithms suffer from its inability in dealing with channel dynamics. The opportunistic methods however, spend more time on probing, and suffer from the myopic decisions as well. We present...
Amplify-and-forward (AF) wireless relay networks in which the source communicates with the relays and destination in the first phase and the relays forward signals to the destination in the second phase over orthogonal and uncorrelated Rayleigh fading channels are considered. Convex programming is used to obtain optimal and approximately optimal power allocation (OPA) schemes to maximize the average...
The availability of cost-effective wireless network interface cards has recently made it possible to equip wireless mesh routers with multiple interfaces. The problem how to assign channels to those interfaces has been consequently studied and shown to be strictly related to the routing problem. In a previous work, we have proposed a Layer-2.5 forwarding paradigm for multi-radio wireless mesh networks...
A smart adaptive antenna has multiple Degrees of Freedom (DOFs), which can be used for intended communications and interference suppression. In this paper, we study routing and scheduling in wireless backhaul networks with smart antennas. In a wireless backhaul network, a spanning tree rooted at the gateway node is usually constructed for routing. We formally define the Interference aware Tree Construction...
Wireless mesh networks (WMNs) are a promising technology for providing broadband wireless access to the end user. They offer a higher degree of flexibility compared to traditional networks but on the expense of a more complex structure. Thus, planning and optimization of WMNs is a challenge. In this paper, we address this challenge using genetic algorithms. Genetic algorithms are able to evaluate...
Wireless mesh network (WMN) is a multi-hop wireless network with partial mesh topology, which can replace wired infrastructure backbone in a traditional wireless network, to wireless. It is an exciting new technology that has applications in defense, metro-area Internet access, and disaster management. WMNs are believed to be a highly promising technology and will play an increasingly important role...
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.