MADServer: An Architecture for Opportunistic Mobile Advanced Delivery

Rapid increases in cellular data traffic demand creative alternative delivery vectors for data. Despite the conceptual attractiveness of mobile data offloading, no concrete web server architectures integrate intelligent offloading in a production-ready and easily deployable manner without relying on vast infrastructural changes to carriers’ networks. Delay-tolerant networking technology offers the means to do just this. We introduce MADServer, a novel DTN-based architecture for mobile data offloading that splits web con- tent among multiple independent delivery vectors based on user and data context. It enables intelligent data offload- ing, caching, and querying solutions which can be incorporated in a manner that still satisfies user expectations for timely delivery. At the same time, it allows for users who have poor or expensive connections to the cellular network to leverage multi-hop opportunistic routing to send and receive data. We also present a preliminary implementation of MADServer and provide real-world performance evaluations

Mobile crowd sensing architectural frameworks: A comprehensive survey

Mobile Crowd Sensing has emerged as a new sensing paradigm, efficiently exploiting human intelligence and mobility in conjunction with advanced capabilities and proliferation of mobile devices. In order for MCS applications to reach their full potentials, a number of research challenges should be sufficiently addressed. The aim of this paper is to survey representative mobile crowd sensing applications and frameworks proposed in related research literature, analyze their distinct features and discuss on their relative merits and weaknesses, highlighting also potential solutions, in order to take a step closer to the definition of a unified MCS architectural framework

HRSON: Home-based Routing for Smartphones in Opportunistic Networks

Opportunistic networks are delay-tolerant networks which enable network connectivity while there is limited access to network infrastructure, such as natural disaster happenings. Since opportunistic networks use store-carry-forward mechanism to deliver data, routing algorithms have significant impact on successful data delivery. Due to the Operating System restrictions, creating an opportunistic network using ad-hoc model is not feasible on smartphones and to the best of our knowledge, none of common zero-knowledge routing algorithms have been proposed for a non-ad hoc communication model. In this paper, we propose HRSON, a zero-knowledge routing algorithm in a self-organizing approach that an opportunistic infrastructure-based WiFi network is built to use smartphones. We have deployed our approach in simulated scenario of working days of people, whom are using smartphones, on Helsinki map comparing to common zero-knowledge routing algorithms. The results show that our solution increases the average delivery-rate and lowers delay and commutation overhead

Context-awareness for mobile sensing: a survey and future directions

The evolution of smartphones together with increasing computational power have empowered developers to create innovative context-aware applications for recognizing user related social and cognitive activities in any situation and at any location. The existence and awareness of the context provides the capability of being conscious of physical environments or situations around mobile device users. This allows network services to respond proactively and intelligently based on such awareness. The key idea behind context-aware applications is to encourage users to collect, analyze and share local sensory knowledge in the purpose for a large scale community use by creating a smart network. The desired network is capable of making autonomous logical decisions to actuate environmental objects, and also assist individuals. However, many open challenges remain, which are mostly arisen due to the middleware services provided in mobile devices have limited resources in terms of power, memory and bandwidth. Thus, it becomes critically important to study how the drawbacks can be elaborated and resolved, and at the same time better understand the opportunities for the research community to contribute to the context-awareness. To this end, this paper surveys the literature over the period of 1991-2014 from the emerging concepts to applications of context-awareness in mobile platforms by providing up-to-date research and future research directions. Moreover, it points out the challenges faced in this regard and enlighten them by proposing possible solutions

Delay Tolerant Networks for Efficient Information Harvesting and Distribution in Intelligent Transportation Systems

[EN] Intelligent Transportation Systems (ITS) can make transportation safer, more efficient, and more sustainable by applying various information and communication technologies. One of these technologies are \acfp{VN}. \acp{VN} combine different communication solutions such as cellular networks, \acfp{VANET}, or IEEE 802.11 technologies to provide connectivity among vehicles, and between vehicles and road infrastructure. This thesis focuses on VNs, and considers that the high speed of the nodes and the presence of obstacles like buildings, produces a highly variable network topology, as well as more frequent partitions in the network. Therefore, classical \ac{MANET} protocols do not adapt well to VANETs. Under these conditions, \ac{DTN} have been proposed as an alternative able to cope with these adverse characteristics. In DTN, when a message cannot be routed to its destination, it is not immediately dropped but it is instead stored and carried until a new route becomes available. The combination of VN and DTN is called \acp{VDTN}. In this thesis, we propose a new VDTN protocol designed to collect information from vehicular sensors. Our proposal, called \ac{MSDP}, combines information about the localization obtained from a GNSS system with the actual street/road layout obtained from a Navigation System (NS) to define a new routing metric. Both analytical and simulation results prove that MSDP outperforms previous proposals. Concerning the deployment of VNs and VANET technologies, technology already left behind the innovation and the standardization phases, and it is about time it reach the first early adopters in the market. However, most car manufacturers have decided to implement VN devices in the form of On Board Units (OBUs), which are expensive, heavily manufacturer dependent, and difficult to upgrade. These facts are delaying the deployment of VN. To boost this process, we have developed the GRCBox architecture. This architecture is based on low-cost devices and enables the establishment of V2X, \emph{i.e.} V2I and V2V, communications while integrating users by easing the use of general purpose devices like smartphones, tablets or laptops. To demonstrate the viability of the GRCBox architecture, we combined it with a DTN platform called Scampi to obtain actual results over a real VDTN scenario. We also present several GRCBox-aware applications that illustrate how developers can create applications that bring the potential of VN to user devices.[ES] Los sistemas de transporte inteligente (ITS) son el soporte para el establecimiento de un transporte más seguro, más eficiente y más sostenible mediante el uso de tecnologías de la información y las comunicaciones. Una de estas tecnologías son las redes vehiculares (VNs). Las VNs combinan diferentes tecnologías de comunicación como las redes celulares, las redes ad-hoc vehiculares (VANETs) o las redes 802.11p para proporcionar conectividad entre vehículos, y entre vehículos y la infraestructura de carreteras. Esta tesis se centra en las VNs, en las cuales la alta velocidad de los nodos y la presencia de obstáculos como edificios producen una topología de red altamente variable, así como frecuentes particiones en la red. Debido a estas características, los protocolos para redes móviles ad-hoc (MANETs) no se adaptan bien a las VANETs. En estas condiciones, las redes tolerantes a retardos (DTNs) se han propuesto como una alternativa capaz de hacer frente a estos problemas. En DTN, cuando un mensaje no puede ser encaminado hacia su destino, no es inmediatamente descartado sino es almacenado hasta que una nueva ruta esta disponible. Cuando las VNs y las DTNs se combinan surgen las redes vehiculares tolerantes a retardos (VDTN). En esta tesis proponemos un nuevo protocolo para VDTNs diseñado para recolectar la información generada por sensores vehiculares. Nuestra propuesta, llamada MSDP, combina la información obtenida del servicio de información geográfica (GIS) con el mapa real de las calles obtenido del sistema de navegación (NS) para definir una nueva métrica de encaminamiento. Resultados analíticos y mediante simulaciones prueban que MSDP mejora el rendimiento de propuestas anteriores. En relación con el despliegue de las VNs y las tecnologías VANET, la tecnología ha dejado atrás las fases de innovación y estandarización, ahora es el momento de alcanzar a los primeros usuarios del mercado. Sin embargo, la mayoría de fabricantes han decidido implementar los dispositivos para VN como unidades de a bordo (OBU), las cuales son caras y difíciles de actualizar. Además, las OBUs son muy dependientes del fabricante original. Todo esto esta retrasando el despliegue de las VNs. Para acelerar la adopción de las VNs, hemos desarrollado la arquitectura GRCBox. La arquitectura GRCBox esta basada en un dispositivo de bajo coste que permite a los usuarios usar comunicaciones V2X (V2V y V2I) mientras utilizan dispositivos de propósito general como teléfonos inteligentes, tabletas o portátiles. Las pruebas incluidas en esta tesis demuestran la viabilidad de la arquitectura GRCBox. Mediante la combinación de nuestra GRCBox y una plataforma de DTN llamada Scampi hemos diseñado y probado un escenario VDTN real. También presentamos como los desarrolladores pueden crear nuevas aplicaciones GRCBox para llevar el potencial de las VN a los dispositivos de usuario.[CA] Els sistemes de transport intel·ligent (ITS) poden crear un transport més segur, més eficient i més sostenible mitjançant l'ús de tecnologies de la informació i les comunicacions aplicades al transport. Una d'aquestes tecnologies són les xarxes vehiculars (VN). Les VN combinen diferents tecnologies de comunicació, com ara les xarxes cel·lulars, les xarxes ad-hoc vehiculars (VANET) o les xarxes 802.11p, per a proporcionar comunicació entre vehicles, i entre vehicles i la infraestructura de carreteres. Aquesta tesi se centra en les VANET, en les quals l'alta velocitat dels nodes i la presència d'obstacles, com els edificis, produeixen una topologia de xarxa altament variable, i també freqüents particions en la xarxa. Per aquest motiu, els protocols per a xarxes mòbils ad-hoc (MANET) no s'adapten bé. En aquestes condicions, les xarxes tolerants a retards (DTN) s'han proposat com una alternativa capaç de fer front a aquests problemes. En DTN, quan un missatge no pot ser encaminat cap a la seua destinació, no és immediatament descartat sinó que és emmagatzemat fins que apareix una ruta nova. Quan les VN i les DTN es combinen sorgeixen les xarxes vehicular tolerants a retards (VDTN). En aquesta tesi proposem un nou protocol per a VDTN dissenyat per a recol·lectar la informació generada per sensors vehiculars. La nostra proposta, anomenada MSDP, combina la informació obtinguda del servei d'informació geogràfica (GIS) amb el mapa real dels carrers obtingut del sistema de navegació (NS) per a definir una nova mètrica d'encaminament. Resultats analítics i mitjançant simulacions proven que MSDP millora el rendiment de propostes prèvies. En relació amb el desplegament de les VN i les tecnologies VANET, la tecnologia ha deixat arrere les fases d'innovació i estandardització, ara és temps d'aconseguir als primers usuaris del mercat. No obstant això, la majoria de fabricants han decidit implementar els dispositius per a VN com a unitats de bord (OBU), les quals són cares i difícils d'actualitzar. A més, les OBU són molt dependents del fabricant original. Tot això està retardant el desplegament de les VN. Per a accelerar l'adopció de les VN, hem desenvolupat l'arquitectura GRCBox. L'arquitectura GRCBox està basada en un dispositiu de baix cost que permet als usuaris usar comunicacions V2V mentre usen dispositius de propòsit general, com ara telèfons intel·ligents, tauletes o portàtils. Les proves incloses en aquesta tesi demostren la viabilitat de l'arquitectura GRCBox. Mitjançant la combinació de la nostra GRCBox i la plataforma de DTN Scampi, hem dissenyat i provat un escenari VDTN pràctic. També presentem com els desenvolupadors poden crear noves aplicacions GRCBox per a portar el potencial de les VN als dispositius d'usuari.Martínez Tornell, S. (2016). Delay Tolerant Networks for Efficient Information Harvesting and Distribution in Intelligent Transportation Systems [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/68486TESI

Code offloading in opportunistic computing

With the advent of cloud computing, applications are no longer tied to a single device, but they can be migrated to a high-performance machine located in a distant data center. The key advantage is the enhancement of performance and consequently, the users experience. This activity is commonly referred computational offloading and it has been strenuously investigated in the past years. The natural candidate for computational offloading is the cloud, but recent results point out the hidden costs of cloud reliance in terms of latency and energy; Cuervo et. al. illustrates the limitations on cloud-based computational offloading based on WANs latency times. The dissertation confirms the results of Cuervo et. al. and illustrates more use cases where the cloud may not be the right choice. This dissertation addresses the following question: is it possible to build a novel approach for offloading the computation that overcomes the limitations of the state-of-the-art? In other words, is it possible to create a computational offloading solution that is able to use local resources when the Cloud is not usable, and remove the strong bond with the local infrastructure? To this extent, I propose a novel paradigm for computation offloading named anyrun computing, whose goal is to use any piece of higher-end hardware (locally or remotely accessible) to offloading a portion of the application. With anyrun computing I removed the boundaries that tie the solution to an infrastructure by adding locally available devices to augment the chances to succeed in offloading. To achieve the goals of the dissertation it is fundamental to have a clear view of all the steps that take part in the offloading process. To this extent, I firstly provided a categorization of such activities combined with their interactions and assessed the impact on the system. The outcome of the analysis is the mapping to the problem to a combinatorial optimization problem that is notoriously known to be NP-Hard. There are a set of well-known approaches to solving such kind of problems, but in this scenario, they cannot be used because they require a global view that can be only maintained by a centralized infrastructure. Thus, local solutions are needed. Moving further, to empirically tackle the anyrun computing paradigm, I propose the anyrun computing framework (ARC), a novel software framework whose objective is to decide whether to offload or not to any resource-rich device willing to lend assistance is advantageous compared to local execution with respect to a rich array of performance dimensions. The core of ARC is the nference nodel which receives a rich set of information about the available remote devices from the SCAMPI opportunistic computing framework developed within the European project SCAMPI, and employs the information to profile a given device, in other words, it decides whether offloading is advantageous compared to local execution, i.e. whether it can reduce the local footprint compared to local execution in the dimensions of interest (CPU and RAM usage, execution time, and energy consumption). To empirically evaluate ARC I presented a set of experimental results on the cloud, cloudlet, and opportunistic domain. In the cloud domain, I used the state of the art in cloud solutions over a set of significant benchmark problems and with three WANs access technologies (i.e. 3G, 4G, and high-speed WAN). The main outcome is that the cloud is an appealing solution for a wide variety of problems, but there is a set of circumstances where the cloud performs poorly. Moreover, I have empirically shown the limitations of cloud-based approaches, specifically, In some circumstances, problems with high transmission costs tend to perform poorly, unless they have high computational needs. The second part of the evaluation is done in opportunistic/cloudlet scenarios where I used my custom-made testbed to compare ARC and MAUI, the state of the art in computation offloading. To this extent, I have performed two distinct experiments: the first with a cloudlet environment and the second with an opportunistic environment. The key outcome is that ARC virtually matches the performances of MAUI (in terms of energy savings) in cloudlet environment, but it improves them by a 50% to 60% in the opportunistic domain