46 research outputs found
A network mobility management architecture for a heteregeneous network environment
Network mobility management enables mobility of personal area networks and vehicular networks across heterogeneous access networks using a Mobile Router. This dissertation presents a network mobility management architecture for minimizing the impact of handoffs on the communications of nodes in the mobile network. The architecture addresses mobility in legacy networks without infrastructure support, but can also exploit infrastructure support for improved handoff performance. Further, the proposed architecture increases the efficiency of communications of nodes in the mobile network with counter parts in the fixed network through the use of caching and route optimization. The performance and costs of the proposed architecture are evaluated through empirical and numerical analysis. The analysis shows the feasibility of the architecture in the networks of today and in those of the near future.Verkkojen liikkuuvudenhallinta mahdollistaa henkilökohtaisten ja ajoneuvoihin asennettujen verkkojen liikkuvuuden heterogeenisessä verkkoympäristössä käyttäen liikkuvaa reititintä. Tämä väitöskirja esittää uuden arkkitehtuurin verkkojen liikkuvuudenhallintaan, joka minimoi verkonvaihdon vaikutuksen päätelaitteiden yhteyksiin.
Vanhoissa verkoissa, joiden infrastruktuuri ei tue verkkojen liikkuvuutta, verkonvaihdos täytyy hallita liikkuvassa reitittimessa. Standardoitu verkkojen liikkuvuudenhallintaprotokolla NEMO mahdollistaa tämän käyttäen ankkurisolmua kiinteässä verkossa pakettien toimittamiseen päätelaitteiden kommunikaatiokumppaneilta liikkuvalle reitittimelle. NEMO:ssa verkonvaihdos aiheuttaa käynnissä olevien yhteyksien keskeytymisen yli sekunnin mittaiseksi ajaksi, aiheuttaen merkittävää häiriötä viestintäsovelluksille.
Esitetyssä arkkitehtuurissa verkonvaihdon vaikutus minimoidaan varustamalla liikkuva reititin kahdella radiolla. Käyttäen kahta radiota liikkuva reititin pystyy suorittamaan verkonvaihdon keskeyttämättä päätelaitteiden yhteyksiä, mikäli verkonvaihtoon on riittävästi aikaa. Käytettävissa oleva aika riippuu liikkuvan reitittimen nopeudesta ja radioverkon rakenteesta. Arkkitehtuuri osaa myös hyödyntää infrastruktuurin tukea saumattomaan verkonvaihtoon. Verkkoinfrastruktuurin tuki nopeuttaa verkonvaihdosprosessia, kasvattaenmaksimaalista verkonvaihdos tahtia. Tällöin liikkuva reitin voi käyttää lyhyen kantaman radioverkkoja, joiden solun säde on yli 80m, ajonopeuksilla 90m/s asti ilman, että verkonvaihdos keskeyttää päätelaitteiden yhteyksiä.
Lisäksi ehdotettu arkkitehtuuri tehostaa kommunikaatiota käyttäen cache-palvelimia liikkuvassa ja kiinteässä verkossa ja optimoitua reititystä liikkuvien päätelaitteiden ja kiinteässä verkossa olevien kommunikaatiosolmujen välillä. Cache-palvelinarkkitehtuuri hyödyntää vapaita radioresursseja liikkuvan verkon cache-palvelimen välimuistin päivittämiseen. Heterogeenisessä verkkoympäristossä cache-palvelimen päivitys suoritetaan lyhyen kantaman laajakaistaisia radioverkkoja käyttäen. Liikkuvan reitittimen siirtyessä laajakaistaisen radioverkon peitealueen ulkopuolelle päätelaitteille palvellaan sisältöä, kuten www sivuja tai videota cache-palvelimelta, säästäen laajemman kantaman radioverkon rajoitetumpia resursseja.
Arkkitehtuurissa käytetään optimoitua reititystä päätelaitteiden ja niiden kommunikaatiokumppaneiden välillä. Optimoitu reititysmekanismi vähentää liikkuvuudenhallintaan käytettyjen protokollien langattoman verkon resurssien kulutusta. Lisäksi optimoitu reititysmekanismi tehostaa pakettien reititystä käyttäen suorinta reittiä kommunikaatiosolmujen välillä.
Esitetyn arkkitehtuurin suorituskyky arvioidaan empiirisen ja numeerisen analyysin avulla. Analyysi arvioi arkkitehtuurin suorituskykyä ja vertaa sitä aikaisemmin ehdotettuihin ratkaisuihin ja osoittaa arkkitehtuurin soveltuvan nykyisiin ja lähitulevaisuuden langattomiin verkkoihin.reviewe
Handover management in mobile WiMAX using adaptive cross-layer technique
The protocol type and the base station (BS) technology are the main communication media between the Vehicle to Infrastructure (V2I) communication in vehicular networks. During high speed vehicle movement, the best communication would be with a seamless handover (HO) delay in terms of lower packet loss and throughput. Many studies have focused on how to reduce the HO delay during lower speeds of the vehicle with data link (L2) and network (L3) layers protocol. However, this research studied the Transport Layer (L4) protocol mobile Stream Control Transmission Protocol (mSCTP) used as an optimal protocol in collaboration with the Location Manager (LM) and Domain Name Server (DNS). In addition, the BS technology that performs smooth HO employing an adaptive algorithm in L2 to perform the HO according to current vehicle speed was also included in the research. The methods derived from the combination of L4 and the BS technology methods produced an Adaptive Cross-Layer (ACL) design which is a mobility oriented handover management scheme that adapts the HO procedure among the protocol layers. The optimization has a better performance during HO as it is reduces scanning delay and diversity level as well as support transparent mobility among layers in terms of low packet loss and higher throughput. All of these metrics are capable of offering maximum flexibility and efficiency while allowing applications to refine the behaviour of the HO procedure. Besides that, evaluations were performed in various scenarios including different vehicle speeds and background traffic. The performance evaluation of the proposed ACL had approximately 30% improvement making it better than the other handover solutions
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
Simultaneous Usage of NEMO and MANET for Vehicular Communication
International audienceMobile Adhoc Network (MANET) routing protocol and NEMO basic support protocol are considered key technologies for vehicle networks. Cooperation between MANET and NEMO (MANEMO) brings several benefits especially for route optimization and multihoming. We setup a real-field testbed on the ANEMONE testbed. In our system, a mobile router has 3 egress interfaces, which is 3G and Wifi to connect the Internet, and other Wifi to connect to Optimized link State Routeing (OLSR) network. All of these interfaces are utilized simultaneously for Inter-vehicle communication. The experimentation results show that MANEMO allows to improve the overall network performance in term of bandwidth and delay
Ubiquitous communications for wireless personal area networks in a heterogeneous environment
The widespread use of wireless technologies has led to a tremendous development in wireless
communication systems. Currently, an individual mobile user may carry multiple personal
devices with multiple wireless interfaces, which can interconnect with each other to form a
Wireless Personal Area Network (WPAN) which moves with this user. These devices exist in
a heterogeneous environment which is composed of various wireless networks with differing
coverage and access technologies and also the topology, device conditions and wireless connections
in the WPAN may be dynamically changing. Such individual mobile users require
ubiquitous communications anytime, anywhere, with any device and wish content to be efficiently
and continuously transferred across the various wireless networks both outside and
inside WPANs, wherever they move.
This thesis presents research carried out into how to implement ubiquitous communications for
WPANs in such an environment. Two main issues are considered. The first is how to initiate
content transfer and keep it continuous, no matter which wireless network is used as a user
moves or how the WPAN changes dynamically. The second is how to implement this transfer
in the most efficient way: selecting the most suitable transfer mode for a WPAN according
to the user’s and application’s requirements. User-centric (personal-area-centric) and contentcentric
mechanisms are proposed in this thesis to address these issues. A scheme based on a
Personal Distributed Environment (PDE) concept and designed as a logical user-based management
entity is presented. This is based on three mechanisms which are proposed to overcome
the technical problems in practical scenarios, which cannot be solved by existing approaches.
A novel mechanism is proposed to combine local direct and global mobile communications, in
order to implement ubiquitous communications in both infrastructure-less and infrastructurebased
networks. This enables an individual user’s ubiquitous communications to be initiated
in an infrastructure-less network environment and kept continuous when they move across
infrastructure-based networks. Its advantages are evaluated by a performance analysis model
and compared to existing solutions and verified by experiments. A cooperation and management
scheme is also proposed for dynamic changes of multiple mobile routers and flexible
switching of personal device roles in a WPAN while keeping ongoing ubiquitous communications
continuous. This adopts a novel view of WPANs which solves the addressing problems
caused by changes of mobile routers and makes these transparent to personal devices in the
WPAN and external content sources. It provides an efficient method for changing the mobile
router of a single WPAN or a WPAN merging with another moving network. Its benefits are
demonstrated through performance analysis models. Finally, a novel user-centric and contentcentric
mechanism for decision making, to select the most appropriate mobile router in a dynamically
changing WPAN environment is proposed. This selects the most suitable content
transfer mode for the WPAN to fulfil an individual user’s various requirements. It has different
strategies to suit various types of applications. Selection results are demonstrated to verify
the proposed mechanism in multiple scenarios of changing user requirements, applications and
WPAN conditions
Evaluation of Network Mobility Schemes for Terrestrial and Satellite Networks
NEtwork MObility (NEMO) supports the mobility of multiple Internet-connected devices. However, NEMO Basic Support Protocol suffers from unoptimized route leading to large latency in communication and header overhead. To optimize route, a plethora of schemes have been proposed. These schemes differ in terms of several performance parameters, such as signaling, end-to-end delay andhandoff latency. However, no performance or cost evaluation exists in the literature to compare the schemes. In addition, mobility management is required to support the mobility of Internet-connected devices in satellite networks. Existing mobility management solutions for satellite networks are unable toprovide connectivity to the Internet when satellites are not directly connected to the ground.In this dissertation, a comprehensive evaluation of the schemes and a mobility management solution for satellite networks using NEMO are provided. The schemes are classified and compared to choose the optimal class. Using analytical and simulation-based models, the schemes in the chosen class are compared based on the performance parameters. The effect of the parameters on transmission Control Protocol, the dominant transport protocol in the Internet, is also evaluated. A cost evaluation is performed to determine the network resource consumption of the schemes. Finally, an architecture and extensions of the basic protocol are presented to apply NEMO in satellite networks. This dissertation fosters the application of NEMO to terrestrial and satellitenetworks by selecting and extending optimal route optimization schemes, and presenting new architecture and protocol
A network mobility management architecture for a heterogeneous network environment
Network mobility management enables mobility of personal area networks and vehicular networks across heterogeneous access networks using a Mobile Router. This dissertation presents a network mobility management architecture for minimizing the impact of handoffs on the communications of nodes in the mobile network. The architecture addresses mobility in legacy networks without infrastructure support, but can also exploit infrastructure support for improved handoff performance. Further, the proposed architecture increases the efficiency of communications of nodes in the mobile network with counter parts in the fixed network through the use of caching and route optimization. The performance and costs of the proposed architecture are evaluated through empirical and numerical analysis. The analysis shows the feasibility of the architecture in the networks of today and in those of the near future.Verkkojen liikkuuvudenhallinta mahdollistaa henkilökohtaisten ja ajoneuvoihin asennettujen verkkojen liikkuvuuden heterogeenisessä verkkoympäristössä käyttäen liikkuvaa reititintä. Tämä väitöskirja esittää uuden arkkitehtuurin verkkojen liikkuvuudenhallintaan, joka minimoi verkonvaihdon vaikutuksen päätelaitteiden yhteyksiin.
Vanhoissa verkoissa, joiden infrastruktuuri ei tue verkkojen liikkuvuutta, verkonvaihdos täytyy hallita liikkuvassa reitittimessa. Standardoitu verkkojen liikkuvuudenhallintaprotokolla NEMO mahdollistaa tämän käyttäen ankkurisolmua kiinteässä verkossa pakettien toimittamiseen päätelaitteiden kommunikaatiokumppaneilta liikkuvalle reitittimelle. NEMO:ssa verkonvaihdos aiheuttaa käynnissä olevien yhteyksien keskeytymisen yli sekunnin mittaiseksi ajaksi, aiheuttaen merkittävää häiriötä viestintäsovelluksille.
Esitetyssä arkkitehtuurissa verkonvaihdon vaikutus minimoidaan varustamalla liikkuva reititin kahdella radiolla. Käyttäen kahta radiota liikkuva reititin pystyy suorittamaan verkonvaihdon keskeyttämättä päätelaitteiden yhteyksiä, mikäli verkonvaihtoon on riittävästi aikaa. Käytettävissa oleva aika riippuu liikkuvan reitittimen nopeudesta ja radioverkon rakenteesta. Arkkitehtuuri osaa myös hyödyntää infrastruktuurin tukea saumattomaan verkonvaihtoon. Verkkoinfrastruktuurin tuki nopeuttaa verkonvaihdosprosessia, kasvattaenmaksimaalista verkonvaihdos tahtia. Tällöin liikkuva reitin voi käyttää lyhyen kantaman radioverkkoja, joiden solun säde on yli 80m, ajonopeuksilla 90m/s asti ilman, että verkonvaihdos keskeyttää päätelaitteiden yhteyksiä.
Lisäksi ehdotettu arkkitehtuuri tehostaa kommunikaatiota käyttäen cache-palvelimia liikkuvassa ja kiinteässä verkossa ja optimoitua reititystä liikkuvien päätelaitteiden ja kiinteässä verkossa olevien kommunikaatiosolmujen välillä. Cache-palvelinarkkitehtuuri hyödyntää vapaita radioresursseja liikkuvan verkon cache-palvelimen välimuistin päivittämiseen. Heterogeenisessä verkkoympäristossä cache-palvelimen päivitys suoritetaan lyhyen kantaman laajakaistaisia radioverkkoja käyttäen. Liikkuvan reitittimen siirtyessä laajakaistaisen radioverkon peitealueen ulkopuolelle päätelaitteille palvellaan sisältöä, kuten www sivuja tai videota cache-palvelimelta, säästäen laajemman kantaman radioverkon rajoitetumpia resursseja.
Arkkitehtuurissa käytetään optimoitua reititystä päätelaitteiden ja niiden kommunikaatiokumppaneiden välillä. Optimoitu reititysmekanismi vähentää liikkuvuudenhallintaan käytettyjen protokollien langattoman verkon resurssien kulutusta. Lisäksi optimoitu reititysmekanismi tehostaa pakettien reititystä käyttäen suorinta reittiä kommunikaatiosolmujen välillä.
Esitetyn arkkitehtuurin suorituskyky arvioidaan empiirisen ja numeerisen analyysin avulla. Analyysi arvioi arkkitehtuurin suorituskykyä ja vertaa sitä aikaisemmin ehdotettuihin ratkaisuihin ja osoittaa arkkitehtuurin soveltuvan nykyisiin ja lähitulevaisuuden langattomiin verkkoihin.reviewe
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