15 research outputs found
On the Throughput-Delay Trade-off in Georouting Networks
We study the scaling properties of a georouting scheme in a wireless
multi-hop network of mobile nodes. Our aim is to increase the network
capacity quasi linearly with while keeping the average delay bounded. In
our model, mobile nodes move according to an i.i.d. random walk with velocity
and transmit packets to randomly chosen destinations. The average packet
delivery delay of our scheme is of order and it achieves the network
capacity of order . This shows a practical
throughput-delay trade-off, in particular when compared with the seminal result
of Gupta and Kumar which shows network capacity of order and
negligible delay and the groundbreaking result of Grossglausser and Tse which
achieves network capacity of order but with an average delay of order
. We confirm the generality of our analytical results using
simulations under various interference models.Comment: This work has been submitted to IEEE INFOCOM 201
Design and implementation of simulation tools, protocols and architectures to support service platforms on vehicular networks
Tesis por compendioProducts related with Intelligent Transportation Systems (ITS) are becoming
a reality on our roads.
All car manufacturers are starting to include Internet
access in their vehicles and to integrate smartphones directly from the
dashboard, but more and more services will be introduced in the near future.
Connectivity through "vehicular networks" will become a cornerstone of every
new proposal, and offering an adequate quality of service is obviously desirable.
However, a lot of work is needed for vehicular networks to offer performances
similar to those of the wired networks.
Vehicular networks can be characterized by two main features: high variability
due to mobility levels that can reach up to 250 kilometers per hour,
and heterogeneity, being that various competing versions from different vendors
have and will be released. Therefore, to make the deployment of efficient
services possible, an extensive study must be carried out and adequate tools
must be proposed and developed. This PhD thesis addresses the service deployment
problem in these networks at three different levels: (i) the physical
and link layer, showing an exhaustive analysis of the physical channel and
models; (ii) the network layer, proposing a forwarding protocol for IP packets;
and (iii) the transport layer, where protocols are proposed to improve data
delivery.
First of all, the two main wireless technologies used in vehicular networks
where studied and modeled, namely the 802.11 family of standards, particularly
802.11p, and the cellular networks focusing on LTE. Since 802.11p is a
quite mature standard, we defined (i) a propagation and attenuation model
capable of replicating the transmission range and the fading behavior of real
802.11p devices, both in line-of-sight conditions and when obstructed by small
obstacles, and (ii) a visibility model able to deal with large obstacles, such
as buildings and houses, in a realistic manner.
Additionally, we proposed a
model based on high-level performance indicators (bandwidth and delay) for
LTE, which makes application validation and evaluation easier.
At the network layer, a hybrid protocol called AVE is proposed for packet
forwarding by switching among a set of standard routing strategies. Depending
on the specific scenario, AVE selects one out of four different routing solutions:
a) two-hop direct delivery, b) Dynamic MANET On-demand (DYMO), c)
greedy georouting, and d) store-carry-and-forward technique, to dynamically
adapt its behavior to the specific situation.
At the transport layer, we proposed a content delivery protocol for reliable
and bidirectional unicast communication in lossy links that improves content
delivery in situations where the wireless network is the bottleneck.
It has
been designed, validated, optimized, and its performance has been analyzed
in terms of throughput and resource efficiency.
Finally, at system level, we propose an edge-assisted computing model that
allows reducing the response latency of several queries by placing a computing
unit at the network edge. This way, traffic traversal through the Internet is
avoided when not needed.
This scheme could be used in both 802.11p and
cellular networks, and in this thesis we decided to focus on its evaluation using
LTE networks.
The platform presented in this thesis combines all the individual efforts to
create a single efficient platform. This new environment could be used by any
provider to improve the quality of the user experience obtainable through the
proposed vehicular network-based services.Los productos relacionados con los Sistemas Inteligentes de Transporte (ITS)
se están transformando en una realidad en nuestras carreteras. Todos los
fabricantes de coches comienzan a incluir acceso a internet en sus vehículos y a
facilitar su integración con los teléfonos móviles, pero más y más servicios se
introducirán en el futuro.
La conectividad usando las "redes vehiculares" se
convertirá en la piedra angular de cada nueva propuesta, y ofrecer una calidad
de servicio adecuada será, obviamente, deseable. Sin embargo, se necesita
una gran cantidad de trabajo para que las redes vehiculares ofrezcan un
rendimiento similar al de las redes cableadas.
Las redes vehiculares quedan definidas por sus dos características básicas:
alto dinamismo, pues los nodos pueden alcanzar una velocidad relativa de más
de 250 km/h; y heterogeneidad, por la gran cantidad de propuestas diferentes
que los fabricantes están lanzando al mercado. Por ello, para hacer posible el
despliegue de servicios sobre ellas, se impone la necesidad de hacer un estudio
en profundidad de este entorno, y deben de proponerse y desarrollarse las
herramientas adecuadas.
Esta tesis ataca la problemática del despliegue de servicios en estas redes
a tres niveles diferentes: (i) el nivel físico y de enlace, mostrando varios análisis
en profundidad del medio físico y modelos derivados para su simulación;
(ii) el nivel de red, proponiendo un protocolo de difusión de la información
para los paquetes IP; y (iii) el nivel de transporte, donde otros protocolos son
propuestos para mejorar el rendimiento del transporte de datos.
En primer lugar, se han estudiado y modelado las dos principales tecnologías
inalámbricas que se utilizan para la comunicación en redes vehiculares,
la rama de estándares 802.11, en concreto 802.11p; y la comunicación celular,
en particular LTE. Dado que el estándar 802.11p es un estándar bastante
maduro, nos centramos en crear (i) un modelo de propagación y atenuación
capaz de replicar el rango de transmisión de dispositivos 802.11p reales, en
condiciones de visión directa y obstrucción por pequeños obstáculos, y (ii) un
modelo de visibilidad capaz de simular el efecto de grandes obstáculos, como
son los edifcios, de una manera realista.
Además, proponemos un modelo
basado en indicadores de rendimiento de alto nivel (ancho de banda y retardo)
para LTE, que facilita la validación y evaluación de aplicaciones.
En el plano de red, se propone un protocolo híbrido, llamado AVE, para
el encaminamiento y reenvío de paquetes usando un conjunto de estrategias
estándar de enrutamiento. Dependiendo del escenario, AVE elige entre cuatro
estrategias diferentes: a) entrega directa a dos saltos, b) Dynamic MANET
On-demand (DYMO) c) georouting voraz, y d) una técnica store-carry-and-
forward, para adaptar su comportamiento dinámicamente a cada situación.
En el plano de transporte, se propone un protocolo bidireccional de distribución
de contenidos en canales con pérdidas que mejora la entrega de contenidos
en situaciones en las que la red es un cuello de botella, como las redes
inalámbricas.
Ha sido diseñado, validado, optimizado, y su rendimiento ha
sido analizado en términos de productividad y eficiencia en la utilización de
recursos.
Finalmente, a nivel de sistema, proponemos un modelo de computación
asistida que permite reducir la latencia en la respuesta a muchas consultas
colocando una unidad de computación en el borde de la red, i.e., la red de
acceso. Este esquema podría ser usado en redes basadas en 802.11p y en redes
celulares, si bien en esta tesis decidimos centrarnos en su evaluación usando
redes LTE.
La plataforma presentada en esta tesis combina todos los esfuerzos individuales
para crear una plataforma única y eficiente. Este nuevo entorno puede
ser usado por cualquier proveedor para mejorar la calidad de la experiencia de
usuario en los servicios desplegados sobre redes vehiculares.Els productes relacionats amb els sistemes intel · ligents de transport (ITS)
s'estan transformant en una realitat en les nostres carreteres. Tots els fabri-
cants de cotxes comencen a incloure accés a internet en els vehicles i a facilitar-
ne la integració amb els telèfons mòbils, però en el futur més i més serveis s'hi
introduiran. La connectivitat usant les xarxes vehicular esdevindrà la pedra
angular de cada nova proposta, i oferir una qualitat de servei adequada serà,
òbviament, desitjable.
No obstant això, es necessita una gran quantitat de
treball perquè les xarxes vehiculars oferisquen un rendiment similar al de les
xarxes cablejades.
Les xarxes vehiculars queden definides per dues característiques bàsiques:
alt dinamisme, ja que els nodes poden arribar a una velocitat relativa de més
de 250 km/h; i heterogeneïtat, per la gran quantitat de propostes diferents
que els fabricants estan llançant al mercat.
Per això, per a fer possible el
desplegament de serveis sobre aquestes xarxes, s'imposa la necessitat de fer un
estudi en profunditat d'aquest entorn, i cal proposar i desenvolupar les eines
adequades.
Aquesta tesi ataca la problemàtica del desplegament de serveis en aquestes
xarxes a tres nivells diferents: (i) el nivell físic i d'enllaç , mostrant diverses
anàlisis en profunditat del medi físic i models derivats per simular-lo; (ii) el
nivell de xarxa, proposant un protocol de difusió de la informació per als
paquets IP; i (iii) el nivell de transport, on es proposen altres protocols per a
millorar el rendiment del transport de dades.
En primer lloc, s'han estudiat i modelat les dues principals tecnologies
sense fils que s'utilitzen per a la comunicació en xarxes vehiculars, la branca
d'estàndards 802.11, en concret 802.11p; i la comunicació cel · lular, en partic-
ular LTE. Atès que l'estàndard 802.11p és un estàndard bastant madur, ens
centrem a crear (i) un model de propagació i atenuació capaç de replicar el
rang de transmissió de dispositius 802.11p reals, en condicions de visió directa
i obstrucció per petits obstacles, i (ii) un model de visibilitat capaç de simular
l'efecte de grans obstacles, com són els edificis, d'una manera realista. A més,
proposem un model basat en indicadors de rendiment d'alt nivell (ample de
banda i retard) per a LTE, que facilita la validació i l'avaluació d'aplicacions.
En el pla de xarxa, es proposa un protocol híbrid, anomenat AVE, per
a l'encaminament i el reenviament de paquets usant un conjunt d'estratègies
estàndard d'encaminament.
Depenent de l'escenari , AVE tria entre quatre
estratègies diferents: a) lliurament directe a dos salts, b) Dynamic MANET
On-demand (DYMO) c) georouting voraç, i d) una tècnica store-carry-and-
forward, per a adaptar-ne el comportament dinàmicament a cada situació.
En el pla de transport, es proposa un protocol bidireccional de distribució
de continguts en canals amb pèrdues que millora el lliurament de continguts
en situacions en què la xarxa és un coll de botella, com les xarxes sense fils.
Ha sigut dissenyat, validat, optimitzat, i el seu rendiment ha sigut analitzat
en termes de productivitat i eficiència en la utilització de recursos.
Finalment, a nivell de sistema, proposem un model de computació assistida
que permet reduir la latència en la resposta a moltes consultes col · locant una
unitat de computació a la vora de la xarxa, és a dir, la xarxa d'accés. Aquest
esquema podria ser usat en xarxes basades en 802.11p i en xarxes cel · lulars, si
bé en aquesta tesi decidim centrar-nos en la seua avaluació usant xarxes LTE.
La plataforma presentada en aquesta tesi combina tots els esforços indi-
viduals per a crear una plataforma única i eficient. Aquest nou entorn pot ser
usat per qualsevol proveïdor per a millorar la qualitat de l'experiència d'usuari
en els serveis desplegats sobre xarxes vehiculars.Báguena Albaladejo, M. (2017). Design and implementation of simulation tools, protocols and architectures to support service platforms on vehicular networks [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/85333TESISCompendi
Towards a Simple Relationship to Estimate the Capacity of Static and Mobile Wireless Networks
Extensive research has been done on studying the capacity of wireless
multi-hop networks. These efforts have led to many sophisticated and customized
analytical studies on the capacity of particular networks. While most of the
analyses are intellectually challenging, they lack universal properties that
can be extended to study the capacity of a different network. In this paper, we
sift through various capacity-impacting parameters and present a simple
relationship that can be used to estimate the capacity of both static and
mobile networks. Specifically, we show that the network capacity is determined
by the average number of simultaneous transmissions, the link capacity and the
average number of transmissions required to deliver a packet to its
destination. Our result is valid for both finite networks and asymptotically
infinite networks. We then use this result to explain and better understand the
insights of some existing results on the capacity of static networks, mobile
networks and hybrid networks and the multicast capacity. The capacity analysis
using the aforementioned relationship often becomes simpler. The relationship
can be used as a powerful tool to estimate the capacity of different networks.
Our work makes important contributions towards developing a generic methodology
for network capacity analysis that is applicable to a variety of different
scenarios.Comment: accepted to appear in IEEE Transactions on Wireless Communication
OBPF: Opportunistic Beaconless Packet Forwarding Strategy for Vehicular Ad Hoc Networks
[EN] In a vehicular ad hoc network, the communication links are unsteady due to the rapidly changing topology, high mobility and traffic density in the urban environment. Most of the existing geographical routing protocols rely on the continuous transmission of beacon messages to update the neighbors' presence, leading to network congestion. Source-based approaches have been proven to be inefficient in the inherently unstable network. To this end, we propose an opportunistic beaconless packet forwarding approach based on a modified handshake mechanism for the urban vehicular environment. The protocol acts differently between intersections and at the intersection to find the next forwarder node toward the destination. The modified handshake mechanism contains link quality, forward progress and directional greedy metrics to determine the best relay node in the network. After designing the protocol, we compared its performance with existing routing protocols. The simulation results show the superior performance of the proposed protocol in terms of packet delay and data delivery ratio in realistic wireless channel conditions.The authors would like to extend their sincere appreciation to the Deanship of Scientific Research at King Saud University for funding this research. The research is supported by Ministry of Education Malaysia (MOE) and conducted in collaboration with Research Management Center (RMC) at Universiti Teknologi Malaysia (UTM) under VOT NUMBER: QJ130000.2528.06H00.Qureshi, KN.; Abdullah, AH.; Lloret, J.; Altameem, A. (2016). OBPF: Opportunistic Beaconless Packet Forwarding Strategy for Vehicular Ad Hoc Networks. KSII Transactions on Internet and Information Systems. 10(5):2144-2165. https://doi.org/10.3837/tiis.2016.05.011S2144216510
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
VANET-enabled eco-friendly road characteristics-aware routing for vehicular traffic
There is growing awareness of the dangers of climate change caused by greenhouse gases. In the coming decades this could result in numerous disasters such as heat-waves, flooding and crop failures. A major contributor to the total amount of greenhouse gas emissions is the transport sector, particularly private vehicles. Traffic congestion involving private vehicles also causes a lot of wasted time and stress to commuters.
At the same time new wireless technologies such as Vehicular Ad-Hoc Networks (VANETs) are being developed which could allow vehicles to communicate with each other. These could enable a number of innovative schemes to reduce traffic congestion and greenhouse gas emissions.
1) EcoTrec is a VANET-based system which allows vehicles to exchange messages regarding traffic congestion and road conditions, such as roughness and gradient. Each vehicle uses the messages it has received to build a model of nearby roads and the traffic on them. The EcoTrec Algorithm then recommends the most fuel efficient route for the vehicles to follow.
2) Time-Ants is a swarm based algorithm that considers not only the amount of cars in the spatial domain but also the amoumt in the time domain. This allows the system to build a model of the traffic congestion throughout the day. As traffic patterns are broadly similar for weekdays this gives us a good idea of what traffic will be like allowing us to route the vehicles more efficiently using the Time-Ants Algorithm.
3) Electric Vehicle enhanced Dedicated Bus Lanes (E-DBL) proposes allowing electric vehicles onto the bus lanes. Such an approach could allow a reduction in traffic congestion on the regular lanes without greatly impeding the buses. It would also encourage uptake of electric vehicles.
4) A comprehensive survey of issues associated with communication centred traffic management systems was carried out
Role of Interference and Computational Complexity in Modern Wireless Networks: Analysis, Optimization, and Design
Owing to the popularity of smartphones, the recent widespread adoption of wireless broadband has resulted in a tremendous growth in the volume of mobile data traffic, and this growth is projected to continue unabated. In order to meet the needs of future systems, several novel technologies have been proposed, including cooperative communications, cloud radio access networks (RANs) and very densely deployed small-cell networks. For these novel networks, both interference and the limited availability of computational resources play a very important role. Therefore, the accurate modeling and analysis of interference and computation is essential to the understanding of these networks, and an enabler for more efficient design.;This dissertation focuses on four aspects of modern wireless networks: (1) Modeling and analysis of interference in single-hop wireless networks, (2) Characterizing the tradeoffs between the communication performance of wireless transmission and the computational load on the systems used to process such transmissions, (3) The optimization of wireless multiple-access networks when using cost functions that are based on the analytical findings in this dissertation, and (4) The analysis and optimization of multi-hop networks, which may optionally employ forms of cooperative communication.;The study of interference in single-hop wireless networks proceeds by assuming that the random locations of the interferers are drawn from a point process and possibly constrained to a finite area. Both the information-bearing and interfering signals propagate over channels that are subject to path loss, shadowing, and fading. A flexible model for fading, based on the Nakagami distribution, is used, though specific examples are provided for Rayleigh fading. The analysis is broken down into multiple steps, involving subsequent averaging of the performance metrics over the fading, the shadowing, and the location of the interferers with the aim to distinguish the effect of these mechanisms that operate over different time scales. The analysis is extended to accommodate diversity reception, which is important for the understanding of cooperative systems that combine transmissions that originate from different locations. Furthermore, the role of spatial correlation is considered, which provides insight into how the performance in one location is related to the performance in another location.;While it is now generally understood how to communicate close to the fundamental limits implied by information theory, operating close to the fundamental performance bounds is costly in terms of the computational complexity required to receive the signal. This dissertation provides a framework for understanding the tradeoffs between communication performance and the imposed complexity based on how close a system operates to the performance bounds, and it allows to accurately estimate the required data processing resources of a network under a given performance constraint. The framework is applied to Cloud-RAN, which is a new cellular architecture that moves the bulk of the signal processing away from the base stations (BSs) and towards a centralized computing cloud. The analysis developed in this part of the dissertation helps to illuminate the benefits of pooling computing assets when decoding multiple uplink signals in the cloud. Building upon these results, new approaches for wireless resource allocation are proposed, which unlike previous approaches, are aware of the computing limitations of the network.;By leveraging the accurate expressions that characterize performance in the presence of interference and fading, a methodology is described for optimizing wireless multiple-access networks. The focus is on frequency hopping (FH) systems, which are already widely used in military systems, and are becoming more common in commercial systems. The optimization determines the best combination of modulation parameters (such as the modulation index for continuous-phase frequency-shift keying), number of hopping channels, and code rate. In addition, it accounts for the adjacent-channel interference (ACI) and determines how much of the signal spectrum should lie within the operating band of each channel, and how much can be allowed to splatter into adjacent channels.;The last part of this dissertation contemplates networks that involve multi-hop communications. Building on the analytical framework developed in early parts of this dissertation, the performance of such networks is analyzed in the presence of interference and fading, and it is introduced a novel paradigm for a rapid performance assessment of routing protocols. Such networks may involve cooperative communications, and the particular cooperative protocol studied here allows the same packet to be transmitted simultaneously by multiple transmitters and diversity combined at the receiver. The dynamics of how the cooperative protocol evolves over time is described through an absorbing Markov chain, and the analysis is able to efficiently capture the interference that arises as packets are periodically injected into the network by a common source, the temporal correlation among these packets and their interdependence
Mobile Ad Hoc Networks
Guiding readers through the basics of these rapidly emerging networks to more advanced concepts and future expectations, Mobile Ad hoc Networks: Current Status and Future Trends identifies and examines the most pressing research issues in Mobile Ad hoc Networks (MANETs). Containing the contributions of leading researchers, industry professionals, and academics, this forward-looking reference provides an authoritative perspective of the state of the art in MANETs. The book includes surveys of recent publications that investigate key areas of interest such as limited resources and the mobility of mobile nodes. It considers routing, multicast, energy, security, channel assignment, and ensuring quality of service. Also suitable as a text for graduate students, the book is organized into three sections: Fundamentals of MANET Modeling and Simulation—Describes how MANETs operate and perform through simulations and models Communication Protocols of MANETs—Presents cutting-edge research on key issues, including MAC layer issues and routing in high mobility Future Networks Inspired By MANETs—Tackles open research issues and emerging trends Illustrating the role MANETs are likely to play in future networks, this book supplies the foundation and insight you will need to make your own contributions to the field. It includes coverage of routing protocols, modeling and simulations tools, intelligent optimization techniques to multicriteria routing, security issues in FHAMIPv6, connecting moving smart objects to the Internet, underwater sensor networks, wireless mesh network architecture and protocols, adaptive routing provision using Bayesian inference, and adaptive flow control in transport layer using genetic algorithms