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27
A Study on the Feasibility of Mobile Gateways for Vehicular Ad-hoc Networks
, 2004
"... Development in Wireless LAN and Cellular technologies has motivated recent efforts to integrate the two. This creates new application scenarios that were not possible before. Vehicles with Wireless LAN radios can use other vehicles with both Wireless LAN and Cellular radios as mobile gateways and co ..."
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Cited by 45 (1 self)
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Development in Wireless LAN and Cellular technologies has motivated recent efforts to integrate the two. This creates new application scenarios that were not possible before. Vehicles with Wireless LAN radios can use other vehicles with both Wireless LAN and Cellular radios as mobile gateways and connect to the outside world. We aim to study the feasibility of such global connectivity from the road through simulation of the underlying connectivity characteristics for varying traffic and gateway densities. The connectivity results suggest that each vehicle should be able to connect to at least one gateway for a majority of time. The average path lifetimes are found to be good enough many traditional Internet applications like FTP and HTTP. The effectiveness of the AODV wireless ad-hoc routing protocol over this scenario is evaluated and shown to perform well for the densities considered. However, the routes created by AODV can break very frequently due to the dynamic nature of mobility involved. We introduce a couple of prediction based routing protocols to minimize these route breakages and thus improve performance. These protocols take advantage of some deterministic characteristics of the mobility model to better predict route breakages and take preemptive action.
Exploiting Regular Hot-Spots for Drive-thru Internet
- IN PROCEEDINGS OF KIVS 2005
, 2005
"... IEEE 802.11 WLAN technology has become an inexpensive, yet powerful access technology that is targeted at mobile users that remain within reach of the hot-spot. Such hot-spots are usually provided by a wireless Internet service provider (WISP) in locations often frequented by travelers. Past measure ..."
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Cited by 15 (10 self)
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IEEE 802.11 WLAN technology has become an inexpensive, yet powerful access technology that is targeted at mobile users that remain within reach of the hot-spot. Such hot-spots are usually provided by a wireless Internet service provider (WISP) in locations often frequented by travelers. Past measurements have shown that WLAN is even able to support mobile users passing by without stopping and “hopping” from one hot-spot to the next. The Drive-thru Internet project develops a disconnection-tolerant architecture that enables such unconventional usage of WLAN technology. In this paper, we focus on two prime aspects relevant for interworking with existing hot-spot installations: we investigate the impact of auto-configuration and authentication and present performance results for a driving user accessing the Internet via a hot-spot using different access link technologies. We finally suggest enhancements to hot-spot architectures to facilitate Drive-thru Internet access.
Connecting Vehicle Scatternets by Internet-Connected Gateways
- in MMC'2003
, 2003
"... This paper presents an approach for interconnecting isolated clouds of an ad hoc network that form a scatternet topology using Internet gateways as intermediate nodes. The architecture developed is intended to augment FleetNet, a highly dynamic ad hoc network for inter-vehicle communications. This i ..."
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Cited by 11 (0 self)
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This paper presents an approach for interconnecting isolated clouds of an ad hoc network that form a scatternet topology using Internet gateways as intermediate nodes. The architecture developed is intended to augment FleetNet, a highly dynamic ad hoc network for inter-vehicle communications. This is achieved by upgrading FleetNet capabilities to establish a communication path between moving vehicles and the Internet via Internet gateways to facilitate direct gateway to gateway communications via the Internet, thus bridging gaps in the network topology and relaying packets closer towards their geographical destination at the same time. After outlining the overall FleetNet approach and its underlying geographical multi-hop routing, we focus on the FleetNet gateway architecture. We describe required modifications to the gateway architecture and to the FleetNet network layer in order to use these gateways as intermediate nodes for FleetNet routing. Finally, we conclude the paper by a short discussion on the prototype gateway implementation and by summarizing first results and ongoing work on inter scatternet communication. 1
Towards Automated Authentication for Mobile Users in WLAN Hot-Spots
- IN PROCEEDINGS OF VTC FALL
, 2005
"... This paper presents an automated user authentication mechanism for WLAN hot-spots that is intended for mobile usage scenarios. Based upon cues from access points and hot-spot infrastructures, we detect availability of hot-spots, deduce the access method and the wireless ISP’s identity, and finally p ..."
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Cited by 9 (7 self)
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This paper presents an automated user authentication mechanism for WLAN hot-spots that is intended for mobile usage scenarios. Based upon cues from access points and hot-spot infrastructures, we detect availability of hot-spots, deduce the access method and the wireless ISP’s identity, and finally perform authentication taking into account user policies. Our approach enables users to authenticate with a hot-spot within a few seconds, enabling their use even from passing vehicles. While our current implementation works with some hot-spots, we have discovered others that are not well-suited for the current scheme. As mid-term remedy, we finally suggest service announcements to inform mobile users about hot-spot capabilities.
Mobility Management for Vehicular Ad Hoc Networks
"... Abstract — Vehicular ad hoc networks are gaining importance for inter-vehicle communication, because they allow for the local communication between vehicles without any infrastructure, configuration effort, and without the high costs of cellular networks. Besides local data exchange, vehicular appli ..."
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Cited by 8 (0 self)
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Abstract — Vehicular ad hoc networks are gaining importance for inter-vehicle communication, because they allow for the local communication between vehicles without any infrastructure, configuration effort, and without the high costs of cellular networks. Besides local data exchange, vehicular applications may be extended by accessing Internet services. The access is provided by Internet gateways installed along the roadside. However, the Internet integration requires a respective mobility support of the vehicular ad hoc network. In this paper we propose MMIP6, a communication protocol that integrates multihop IPv6-based vehicular ad hoc networks into the Internet. Whereas existing approaches are focused on small-scale ad hoc networking scenarios, MMIP6 is highly optimized for scalability and efficiency. The evaluation showed that MMIP6 is a suitable solution providing a scalable mobility support with an acceptable performance characteristic. I.
Service maps for heterogeneous network environments
- PROC. MOBILE DATA MANAGEMENT CONFERENCE
, 2006
"... Future heterogeneous wireless networks will encompass different link layer technologies and allow selecting the most appropriate network depending on different criteria. To support mobile nodes in the selection process, network information services are developed that provide the mobile node with suf ..."
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Cited by 5 (2 self)
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Future heterogeneous wireless networks will encompass different link layer technologies and allow selecting the most appropriate network depending on different criteria. To support mobile nodes in the selection process, network information services are developed that provide the mobile node with sufficient information about its network neighborhood, typically focusing on the optimization of handover processes. In this paper, we take a more general approach towards network information services, which is needed to support mobile communications in the existing environments of WLAN hotspots and wide area mobile communications networks. We introduce the notion of “service maps”, a mobile data management approach allowing a mobile user to obtain a detailed view of available networks and the services they offer depending on the user context such as geographic position, mobility paths, and application requirements. We review our experiences with networking in highly mobile scenarios from which we derive a set of requirements for a general information service and present our system design and data model that also accounts for business and (incremental) deployment considerations.
A Gateway Architecture for Mobile Multimedia Streaming
- In European Symposium on Mobile Media Delivery (EuMob06
, 2006
"... Transmission of digital audio and video streams is one of the major applications in future wireless networks. Increasing bandwidths and processing power make it possible to receive video streams almost everywhere. But the classes of mobile devices vary from multimedia enabled mobile phones to high-e ..."
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Cited by 3 (0 self)
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Transmission of digital audio and video streams is one of the major applications in future wireless networks. Increasing bandwidths and processing power make it possible to receive video streams almost everywhere. But the classes of mobile devices vary from multimedia enabled mobile phones to high-end notebooks. The capabilities of these devices such as display resolution, processing power, memory size or network connection vary also so that we have to deal with a great heterogeneity of client devices. Thus, content providers have to take into account plenty of different requirements when offering video streams to users with mobile devices. In this paper we present a comprehensive gateway architecture for multimedia streaming using IETF standard protocols such as RTSP and RTP. This gateway system provides a video adaptation service for users with mobile devices. A mobile client discovers an appropriate gateway by using a gateway location mechanism. Based on the capabilities of the mobile device as well as on the user’s preferences, a suitable media format and adaptation method are chosen at the gateway by which the video is tailored to the requirements of the client. 1.
A Mobile Access Gateway for Managing Intermittent Connectivity
- IN THE PROCEEDINGS OF THE IST MOBILE AND WIRELESS COMMUNICATION SUMMIT
, 2005
"... The Drive-thru Internet architecture allows exploiting intermittent connectivity by temporarily connecting to IEEE 802.11 WLAN access points at the roadside from moving vehicles. This poses numerous challenges to a mobile user’s equipment: extreme networking characteristics such as short periods of ..."
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Cited by 3 (3 self)
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The Drive-thru Internet architecture allows exploiting intermittent connectivity by temporarily connecting to IEEE 802.11 WLAN access points at the roadside from moving vehicles. This poses numerous challenges to a mobile user’s equipment: extreme networking characteristics such as short periods of connectivity, unpredictable disconnection times, and vastly varying transmission characteristics. Heterogeneous WLAN hot-spot installations may also require different authentication mechanisms and credentials. We have designed a mobile access gateway to deal with these issues on behalf of a user (group) in a moving vehicle and provide usable connectivity for applications without requiring manual operation. The gateway maximizes the use of short connectivity periods by detecting network access providing signaling functions for local application processes. It also allows using dedicated radio equipment to prolong connectivity periods. Finally, in selected multi-user scenarios, further performance improvements are conceivable by sharing (non-confidential) information across users and applications.
Experimental Characterization of Communications in Vehicular Ad Hoc Network
"... in the ..."
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On the Feasibility of Using Public Transport as Data Mules for Traffic Monitoring
"... Abstract — A broad range of diverse technologies, known collectively as intelligent transportation systems (ITS), holds the answer to many of our transportation problems. ITS provides the intelligent link between travellers, vehicles, and infrastructure. In this paper, we study the feasibility of an ..."
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Cited by 2 (0 self)
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Abstract — A broad range of diverse technologies, known collectively as intelligent transportation systems (ITS), holds the answer to many of our transportation problems. ITS provides the intelligent link between travellers, vehicles, and infrastructure. In this paper, we study the feasibility of an architecture that involves deploying mobile gateways on a selected subset of public transport vehicles for one particular ITS application: traffic monitoring. We assume that all buses, bus stops and traffic lights are equipped with a wireless device to communicate with in-range neighbours (e.g. other buses). In our analysis, we use realistic movement patterns of public transport buses in a metropolitan city. Our results suggest that it is feasible to use such an architecture with existing radio technologies for traffic monitoring applications. I.
