32 research outputs found
Validation and evaluation of NEMO in VANET using geographic routing
International audienceThe combination of geographic-based routing protocols (GeoNetworking) and IPv6 NEtwork MObility (NEMO) into a single communication architecture (IPv6 GeoNetworking) is key in Vehicular Ad-hoc Networks (VANET). While NEMO manages Internet access and session continuity between the vehicle and the Internet, geographically based data forwarding allows an efficient dissemination of the information between vehicles and the infrastructure. In this paper, we refer to the basic scenarios that led to the design of the IPv6 GeoNetworking architecture in the context of the GeoNet project. A prototype implementation of the modules that couple these two technologies is described, in particular the adaptation of IPv6 and C2CNet, a layer that ensures the geographic capabilities. Results of a light experimental performance evaluation are reported
A usage oriented analysis of vehicular networks: from technologies to applications
The research world is paying a lot of attention on vehicular networks nowadays. Novel vehicular services need a suitable communication channel in order to extend in-car capabilities and, generally, be aware about surrounding events. Such networks, however, present some special features, such as high mobility or specific topologies. These properties affect the performance of applications, and more effort should be directed to identify the necessities of the network. Few works deal with application requirements which should be considered when the vehicular network is designed. In this paper, we fill the gap, and propose an analysis of application requirements considering available technologies for the lower and network layer. This study contains key factors which must be taken into account not only at the designing stage of the vehicular services, but also when applications are evaluated.The authors would like to thank the Spanish Ministerio the Educación y Ciencia for sponsoring the research activities under the grant AP2005-1437, in frames of the FPU program
Securing IP Mobility Management for Vehicular Ad Hoc Networks
The proliferation of Intelligent Transportation Systems (ITSs) applications, such as
Internet access and Infotainment, highlights the requirements for improving the underlying
mobility management protocols for Vehicular Ad Hoc Networks (VANETs). Mobility
management protocols in VANETs are envisioned to support mobile nodes (MNs), i.e.,
vehicles, with seamless communications, in which service continuity is guaranteed while
vehicles are roaming through different RoadSide Units (RSUs) with heterogeneous wireless
technologies.
Due to its standardization and widely deployment, IP mobility (also called Mobile IP
(MIP)) is the most popular mobility management protocol used for mobile networks including
VANETs. In addition, because of the diversity of possible applications, the Internet
Engineering Task Force (IETF) issues many MIP's standardizations, such as MIPv6 and
NEMO for global mobility, and Proxy MIP (PMIPv6) for localized mobility. However,
many challenges have been posed for integrating IP mobility with VANETs, including the
vehicle's high speeds, multi-hop communications, scalability, and ef ficiency. From a security
perspective, we observe three main challenges: 1) each vehicle's anonymity and location
privacy, 2) authenticating vehicles in multi-hop communications, and 3) physical-layer
location privacy.
In transmitting mobile IPv6 binding update signaling messages, the mobile node's Home
Address (HoA) and Care-of Address (CoA) are transmitted as plain-text, hence they can
be revealed by other network entities and attackers. The mobile node's HoA and CoA
represent its identity and its current location, respectively, therefore revealing an MN's HoA
means breaking its anonymity while revealing an MN's CoA means breaking its location
privacy. On one hand, some existing anonymity and location privacy schemes require
intensive computations, which means they cannot be used in such time-restricted seamless
communications. On the other hand, some schemes only achieve seamless communication
through low anonymity and location privacy levels. Therefore, the trade-off between the
network performance, on one side, and the MN's anonymity and location privacy, on the
other side, makes preservation of privacy a challenging issue. In addition, for PMIPv6
to provide IP mobility in an infrastructure-connected multi-hop VANET, an MN uses a
relay node (RN) for communicating with its Mobile Access Gateway (MAG). Therefore,
a mutual authentication between the MN and RN is required to thwart authentication
attacks early in such scenarios. Furthermore, for a NEMO-based VANET infrastructure,
which is used in public hotspots installed inside moving vehicles, protecting physical-layer
location privacy is a prerequisite for achieving privacy in upper-layers such as the IP-layer. Due to the open nature of the wireless environment, a physical-layer attacker can easily
localize users by employing signals transmitted from these users.
In this dissertation, we address those security challenges by proposing three security
schemes to be employed for different mobility management scenarios in VANETs, namely,
the MIPv6, PMIPv6, and Network Mobility (NEMO) protocols.
First, for MIPv6 protocol and based on the onion routing and anonymizer, we propose
an anonymous and location privacy-preserving scheme (ALPP) that involves two complementary
sub-schemes: anonymous home binding update (AHBU) and anonymous return
routability (ARR). In addition, anonymous mutual authentication and key establishment
schemes have been proposed, to authenticate a mobile node to its foreign gateway and
create a shared key between them. Unlike existing schemes, ALPP alleviates the tradeoff
between the networking performance and the achieved privacy level. Combining onion
routing and the anonymizer in the ALPP scheme increases the achieved location privacy
level, in which no entity in the network except the mobile node itself can identify this
node's location. Using the entropy model, we show that ALPP achieves a higher degree of
anonymity than that achieved by the mix-based scheme. Compared to existing schemes,
the AHBU and ARR sub-schemes achieve smaller computation overheads and thwart both
internal and external adversaries. Simulation results demonstrate that our sub-schemes
have low control-packets routing delays, and are suitable for seamless communications.
Second, for the multi-hop authentication problem in PMIPv6-based VANET, we propose
EM3A, a novel mutual authentication scheme that guarantees the authenticity of both
MN and RN. EM3A thwarts authentication attacks, including Denial of service (DoS), collusion,
impersonation, replay, and man-in-the-middle attacks. EM3A works in conjunction
with a proposed scheme for key establishment based on symmetric polynomials, to generate
a shared secret key between an MN and an RN. This scheme achieves lower revocation
overhead than that achieved by existing symmetric polynomial-based schemes. For a PMIP
domain with n points of attachment and a symmetric polynomial of degree t, our scheme
achieves t x 2^n-secrecy, whereas the existing symmetric polynomial-based authentication
schemes achieve only t-secrecy. Computation and communication overhead analysis as well
as simulation results show that EM3A achieves low authentication delay and is suitable
for seamless multi-hop IP communications. Furthermore, we present a case study of a
multi-hop authentication PMIP (MA-PMIP) implemented in vehicular networks. EM3A
represents the multi-hop authentication in MA-PMIP to mutually authenticate the roaming
vehicle and its relay vehicle. Compared to other authentication schemes, we show that our
MA-PMIP protocol with EM3A achieves 99.6% and 96.8% reductions in authentication
delay and communication overhead, respectively.
Finally, we consider the physical-layer location privacy attacks in the NEMO-based
VANETs scenario, such as would be presented by a public hotspot installed inside a moving
vehicle. We modify the obfuscation, i.e., concealment, and power variability ideas and
propose a new physical-layer location privacy scheme, the fake point-cluster based scheme,
to prevent attackers from localizing users inside NEMO-based VANET hotspots. Involving
the fake point and cluster based sub-schemes, the proposed scheme can: 1) confuse
the attackers by increasing the estimation errors of their Received Signal Strength (RSSs)
measurements, and 2) prevent attackers' monitoring devices from detecting the user's transmitted
signals. We show that our scheme not only achieves higher location privacy, but
also increases the overall network performance. Employing correctness, accuracy, and certainty
as three different metrics, we analytically measure the location privacy achieved by
our proposed scheme. In addition, using extensive simulations, we demonstrate that the
fake point-cluster based scheme can be practically implemented in high-speed VANETs'
scenarios
On the design of efficient Vehicular Applications
International audienceVehicular communications attract the attention of many people in the networking research world. These networks present some special features, such as high mobility or specific topologies, which affect the performance of applications. In order to select the appropriate technologies, more effort should be directed to identify the final necessities of the network. Few works identify possible applications of vehicular networks, but none of them link application requirements which networking technologies available in the vehicular field. In this paper, we fill this gap, and propose an analysis of application requirements and study how to deal with them using communication technologies for the physical and network level. This study contains key factors which must be taken into account, especially, at the designing stage of the vehicular network
Connecting vehicular networks to the internet : a life time-based routing protocol
Inter-Vehicle Communications have recently attracted the attention of researchers in academia and industry. In such networks, vehicles should be able to communicate among each other (V2V) as well as with roadside Infrastructure units (V2I). Vehicular networks try to provide safety on the roads by disseminating critical messages among vehicles. Infrastructure units provide some services such as driver information systems and Internet access. Because of the high speed and high mobility of vehicles, establishing and maintaining a connection to these units is very challenging. We introduce a new protocol that uses the characteristics of vehicle movements to predict the vehicle behavior and select a route with the longest life-time to connect to the wired network. It aims at spreading the advertisement messages through multi-hops without flooding the network, do seamless hand-overs and select the most stable routes to these units. We performed some simulations and compared the performance of our work with some well-known protocols
IPv6 support for VANET with geographical routing
International audienceIPv6 support is needed in vehicular ad hoc network (VANET) with geographical routing. Basic IPv6 protocols such as address auto-configuration assume multicast capable link. However, in VANET, the definition of link becomes ambiguous and it is difficult to support link-scope multicast. Artificial emulation of multicast capable link like Ethernet is possible but may cause low efficiency and high cost. A new way to efficiently run IPv6 over VANET is needed and this paper proposes such a scheme. Our proposal takes the architecture defined by the C2C-CC (Carto- Car Communication Consortium) as a reference system and exploits its inherent features to perform IPv6 operations without link-scope multicast
Quality-Driven Cross-Layer Protocols for Video Streaming over Vehicular Ad-Hoc Networks
The emerging vehicular ad-hoc networks (VANETs) offer a variety of applications
and new potential markets related to safety, convenience and entertainment, however,
they suffer from a number of challenges not shared so deeply by other types of existing
networks, particularly, in terms of mobility of nodes, and end-to-end quality of service
(QoS) provision. Although several existing works in the literature have attempted to
provide efficient protocols at different layers targeted mostly for safety applications, there remain many barriers to be overcome in order to constrain the widespread use of such networks for non-safety applications, specifically, for video streaming: 1) impact of high
speed mobility of nodes on end-to-end QoS provision; 2) cross-layer protocol design while keeping low computational complexity; 3) considering customer-oriented QoS metrics in the design of protocols; and 4) maintaining seamless single-hop and multi-hop connection between the destination vehicle and the road side unit (RSU) while network is moving.
This thesis addresses each of the above limitations in design of cross-layer protocols for video streaming application. 1) An adaptive MAC retransmission limit selection scheme is proposed to improve the performance of IEEE 802.11p standard MAC protocol for video streaming applications over VANETs. A multi-objective optimization framework, which jointly minimizes the probability of playback freezes and start-up delay of the streamed video at the destination vehicle by tuning the MAC retransmission limit with respect to channel statistics as well as packet transmission rate, is applied at road side unit (RSU). Two-hop transmission is applied in zones in which the destination
vehicle is not within the transmission range of any RSU. In the multi-hop scenario, we
discuss the computation of access probability used in the MAC adaptation scheme and propose a cross-layer path selection scheme; 2) We take advantage of similarity between multi-hop urban VANETs in dense traffic conditions and mesh connected networks. First, we investigate an application-centric routing scheme for video streaming over mesh connected overlays. Next, we introduce the challenges of urban VANETs compared to mesh networks and extend the proposed scheme in mesh network into a protocol for urban VANETs. A classification-based method is proposed to select an optimal path for video streaming over multi-hop mesh networks. The novelty is to translate the path selection
over multi-hop networks to a standard classification problem. The classification is based on minimizing average video packet distortion at the receiving nodes. The classifiers are trained offline using a vast collection of video sequences and wireless channel conditions in order to yield optimal performance during real time path selection. Our method substantially reduces the complexity of conventional exhaustive optimization methods and results in high quality (low distortion). Next, we propose an application-centric routing scheme for real-time video transmission over urban multi-hop vehicular ad-hoc network
(VANET) scenarios. Queuing based mobility model, spatial traffic distribution and prob-
ability of connectivity for sparse and dense VANET scenarios are taken into consideration
in designing the routing protocol. Numerical results demonstrate the gain achieved by
the proposed routing scheme versus geographic greedy forwarding in terms of video frame distortion and streaming start-up delay in several urban communication scenarios for various vehicle entrance rate and traffic densities; and 3) finally, the proposed quality-driven
routing scheme for delivering video streams is combined with a novel IP management
scheme. The routing scheme aims to optimize the visual quality of the transmitted video
frames by minimizing the distortion, the start-up delay, and the frequency of the streaming freezes. As the destination vehicle is in motion, it is unrealistic to assume that the vehicle will remain connected to the same access router (AR) for the whole trip. Mobile IP management schemes can benefit from the proposed multi-hop routing protocol in order to adapt proxy mobile IPv6 (PMIPv6) for multi-hop VANET for video streaming applications. The proposed cross-layer protocols can significantly improve the video streaming quality in terms of the number of streaming freezes and start-up delay over VANETs while achieving low computational complexity by using pattern classification methods for optimization