Results 1 - 10 of 22

N.: Net-X: System eXtensions for Supporting Multiple Channels, Multiple Radios, and Other Radio Capabilities

by Pradeep Kyasanur, Chandrakanth Chereddi, Nitin H. Vaidya , 2006
"... Abstract — There are several interface capabilities that may be available in next generation wireless networks. Some examples of interface capabilities include the ability to set the channel of operation and data rate on a frequent basis, and the ability to equip devices with multiple radio interfac ..."
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Abstract — There are several interface capabilities that may be available in next generation wireless networks. Some examples of interface capabilities include the ability to set the channel of operation and data rate on a frequent basis, and the ability to equip devices with multiple radio interfaces and multiple antennas. It may be possible to significantly improve the performance of wireless networks by exploiting the interface capabilities through carefully designed protocols. However, current operating systems have poor support for implementing protocols that need to use the available interface capabilities. The goal of the Net-X project is to develop operating system support for utilizing interface capabilities. As a first step in this direction, we have developed an architecture in Linux to support the use of multiple channels, multiple interfaces, and interface switching. This support has been used to implement a set of multichannel protocols that we had previously developed. In this report, we will describe the new architectural support, implementation of the multichannel protocols, and the use of the protocols in a mesh network. We also describe how the architecture may be extended to support the use of other interface capabilities as well. I.
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An inter-domain routing protocol for multi-homed wireless mesh networks

by Yair Amir, Claudiu Danilov, Raluca Musăloiu-elefteri, Nilo Rivera - International Symposium on a World of Wireless, Mobile and Multimedia Networks (WoWMoM 2007 , 2007
"... This paper presents a routing protocol for multi-homed wireless mesh networks that provide uninterrupted connectivity and fast handoff. Our approach integrates wireless and wired connectivity, using multicast groups to coordinate decisions and seamlessly transfer connections between several Internet ..."
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This paper presents a routing protocol for multi-homed wireless mesh networks that provide uninterrupted connectivity and fast handoff. Our approach integrates wireless and wired connectivity, using multicast groups to coordinate decisions and seamlessly transfer connections between several Internet gateways as mobile clients move between access points. The protocol optimizes the use of the wireless medium by short-cutting wireless hops through wired connections, paying a very low overhead during handoffs. The paper demonstrates that inter-domain handoffs occur instantaneously, with virtually no loss or delay, for both TCP and UDP connections. 1.
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MRP: Wireless Mesh Networks Routing Protocol

by Jangeun Jun, Mihail L. Sichitiu
"... Wireless Mesh Networks (WMNs) are one of the few commonly implemented types of mobile ad-hoc networks (MANETs); several companies offer WMNs for broadband Internet access and for extending the coverage of wireless local area networks. Several particularities differentiate WMNs from MANETs. First, in ..."
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Wireless Mesh Networks (WMNs) are one of the few commonly implemented types of mobile ad-hoc networks (MANETs); several companies offer WMNs for broadband Internet access and for extending the coverage of wireless local area networks. Several particularities differentiate WMNs from MANETs. First, in WMNs, most of the traffic originates or terminates at the gateways (nodes connected to the wired infrastructure/Internet). Second, in most applications, WMN nodes tend to be neatly differentiated as either stationary nodes (providing connectivity and coverage) or mobile nodes (utilizing the coverage afforded by the stationary nodes). While general MANET routing protocols can be used in WMNs, it is expected that a protocol that takes the particularities of WMNs into account will outperform the general protocol. In this paper, we propose such a routing protocol and evaluate its performance via simulations. We show that, for WMNs, the proposed routing protocol outperforms general purpose MANET protocols in terms of routing overhead, packet delivery ratio, throughput and delay.

Routing Protocols for k-hop Networks

by William Douglass List , 2003
"... Previous research has identified the scalability limitations of stand-alone wireless ad hoc networks. Shared access to a single wireless channel in the presence of a dense network leads to congestion and high channel contention. Increasing the diameter of the network introduces long paths that becom ..."
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Previous research has identified the scalability limitations of stand-alone wireless ad hoc networks. Shared access to a single wireless channel in the presence of a dense network leads to congestion and high channel contention. Increasing the diameter of the network introduces long paths that become prone to breakage, leading to degraded performance. As such, in this thesis we propose that the scope of a node’s ad hoc capabilities be limited to a maximum diameter of k hops where k is small, in order to trade off connectivity with overhead. In addition, we suggest an overlay of fixed base stations equipped with a secondary high-bandwidth channel to support connections between nodes in the network, with a maximum of 2k wireless hops. We present our k-hop network architecture and propose several routing protocols specifically tailored for the architecture. We demonstrate through simulations that these routing protocols provide efficient and reliable routing even in the presence of mobility and high node density. Finally, we describe our testbed here at UIUC that has put into practice the k-hop architecture.

Vehicular Grid Communications: The Role of the Internet Infrastructure

by Mario Gerla, Biao Zhou, Yeng-zhong Lee, Fabio Soldo, Uichin Lee, Gustavo Marfia - Proc of the 1st International Conference on Genetic Algorithms and their Applications , 2006
"... Vehicle communications are becoming a reality, driven by navigation safety requirements and by the investments of car manufacturers and Public Transport Authorities. As a consequence many of the essential vehicle grid components (radios, Access Points, spectrum, standards, etc.) will soon be in plac ..."
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Vehicle communications are becoming a reality, driven by navigation safety requirements and by the investments of car manufacturers and Public Transport Authorities. As a consequence many of the essential vehicle grid components (radios, Access Points, spectrum, standards, etc.) will soon be in place (and paid for) paving the way to unlimited opportunities for other car-to-car applications beyond safe navigation, for example, from news to entertainment, mobile network games and civic defense. In this study, we take a visionary look at these future applications, the emerging “Vehicular Grid ” that will support them and the interplay between the grid and the communications infrastructure. In essence, the Vehicular Grid is a large scale ad hoc network. However, an important feature of the Vehicular Grid, which sets it apart from most instantly-deployed ad hoc networks, is the ubiquitous presence of the infrastructure (and the opportunity to use it). While the Vehicular Grid must be entirely self-supporting for emergency operations (natural disaster, terrorist attack, etc), it should exploit the infrastructure (when present) during normal operations. In this paper we address the interaction between vehicles and Internet servers through Virtual Grid and Internet Infrastructure. This includes transparent geo-route provisioning across the Internet, mobile resource monitoring, and mobility management (using back up services in case of infrastructure failure). We then focus on routing and show the importance of Infrastructure cooperation and feedback for efficient, congestion free routing.
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A low-cost and simpleto-deploy peer-to-peer wireless network based on open source linux routers

by N. Tsarmpopoulos, Ǿ. Kalavros, S. Lalis - In International Conference on Testbeds and Research Infrastructures for the DEvelopment of NeTworks and COMmunities (TRIDENTCOM’05 , 2005
"... In this paper we present our work towards deploying a community wireless network with ad hoc communication and routing between its elements. We describe our network model and implementation of wireless routers, while motivating decisions and pointing out open issues. The main advantage of our approa ..."
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In this paper we present our work towards deploying a community wireless network with ad hoc communication and routing between its elements. We describe our network model and implementation of wireless routers, while motivating decisions and pointing out open issues. The main advantage of our approach is the low deployment cost and inherent flexibility in terms of adapting the network configuration with little or no human intervention, which in turn can be exploited to support the dynamic addition, removal and mobility of network elements. 1.
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High Throughput Routing in Hybrid Cellular and Ad-Hoc Networks

by Ioannis Ioannidis, Bogdan Carbunar, Cristina Nita-rotaru
"... In this paper we present DST, a routing protocol for hybrid networks that is scalable with the network size and achieves high throughput by taking advantage of multiple channels. DST maintains a close to optimal spanning tree of the network by using distributed topology trees. DST is fully dynamic a ..."
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In this paper we present DST, a routing protocol for hybrid networks that is scalable with the network size and achieves high throughput by taking advantage of multiple channels. DST maintains a close to optimal spanning tree of the network by using distributed topology trees. DST is fully dynamic and generates only O(log n) messages per update operation. We show experimentally that DST scales well with the network size, making it ideal for the metropolitan environment hybrid networks are expected to operate in. 1
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JANUS: A Framework for Scalable and Secure Routing in Hybrid Wireless Networks

by Bogdan Carbunar, Ioannis Ioannidis, Cristina Nita-Rotaru
"... Hybrid networks consisting of cellular and Wi-Fi networks were proposed as a high-throughput architecture for cellular services. In such networks, devices equipped with cellular and Wi-Fi network cards access Internet services through the cellular base station. The Wi-Fi interface is used to provi ..."
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Hybrid networks consisting of cellular and Wi-Fi networks were proposed as a high-throughput architecture for cellular services. In such networks, devices equipped with cellular and Wi-Fi network cards access Internet services through the cellular base station. The Wi-Fi interface is used to provide a better service to clients that are far away from the base station, via multihop, ad hoc paths. The modified trust model of hybrid networks generates a set of new security challenges as clients rely on intermediate nodes to participate effectively in the resource reservation process and data forwarding. In this paper we introduce JANUS, a framework for scalable, secure and efficient routing for hybrid cellular and Wi-Fi networks. JANUS uses a scalable routing algorithm with multiple channel access, for improved network throughput. In addition, it provides protection against selfish nodes through a secure crediting protocol and protection against malicious nodes through secure route establishment and data forwarding mechanisms. We evaluate JANUS experimentally and show that its performance is 85 % of the optimum algorithm, improving with a factor greater than 50 % over previous work. We evaluate the security overhead of JANUS against two type of attacks: less aggressive, but sufficient for some applications, selfish attacks, and purely malicious attacks.
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Secure Unified Cellular Ad Hoc Network Routing

by Jason J. Haas, Yih-chun Hu
"... Abstract—Previous simulations have shown substantial performance gains can be achieved by using hybrid cellular and wireless LAN (WLAN) approaches [1]. In a hybrid system, a proxy in an area of strong connectivity (and therefore higher bandwidth) forwards traffic on behalf of a client in an area of ..."
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Abstract—Previous simulations have shown substantial performance gains can be achieved by using hybrid cellular and wireless LAN (WLAN) approaches [1]. In a hybrid system, a proxy in an area of strong connectivity (and therefore higher bandwidth) forwards traffic on behalf of a client in an area of weaker connectivity (and therefore lower bandwidth). The proxy routes traffic between the base station (over a cellular link) and the client (over a WLAN). Such approaches have had limited practical applicability due to substantial security risks, including eavesdropping, intentional performance degradation and cheating the incentive schemes. The Secure Unified Cellular Ad Hoc Network (SUCAN) protocol is designed to address these risks, allowing the deployment of hybrid networks. SUCAN uses incentives and cryptographic techniques to eliminate cheating by self-interested hosts, while limiting the damage caused by malicious hosts. We implemented SUCAN on Verizon’s Broadband Access network. To our knowledge, this is the first realworld implementation of a hybrid cellular network protocol. Our implementation results show that the SUCAN system can provide substantial performance increases and protects against performance degradation even in the presence of malicious behavior. I.

ECEASST Virtual WLAN: Going beyond Virtual Access Points

by Wissenschaftlichen Konferenz, Hakan Coskun, Ina Schieferdecker, Yahya Al-hazmi, M. Wagner, D. Hogrefe, K. Geihs, K. David, Hakan Coskun, Ina Schieferdecker, Yahya Al-hazmi
"... Abstract: Wireless nodes equipped with multiple radio interfaces open up new fields of application. Ranging from multi-channel usage in a cell in order to in-crease the bandwidth to the creation of meshed multi-hop topologies. Using mul-tiple wireless cards demands a large physical space, more energ ..."
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Abstract: Wireless nodes equipped with multiple radio interfaces open up new fields of application. Ranging from multi-channel usage in a cell in order to in-crease the bandwidth to the creation of meshed multi-hop topologies. Using mul-tiple wireless cards demands a large physical space, more energy consumption and as a consequence decreasing in the battery lifetime. Virtualization of the wireless network interface, which means to use a single wireless network interface to con-nect to more than one network simultaneously, seems to be a promising approach, since it allows us to realize the mentioned scenarios only with one radio interface. In this paper, we want to shed light on the state of the art and want to introduce new approaches to push this field beyond the current status.
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