A Credit-based Home Access Point (CHAP) to Improve Application Quality on IEEE 802.11 Networks

Increasing availability of high-speed Internet and wireless access points has allowed home users to connect not only their computers but various other devices to the Internet. Every device running different applications requires unique Quality of Service (QoS). It has been shown that delay- sensitive applications, such as VoIP, remote login and online game sessions, suffer increased latency in the presence of throughput-sensitive applications such as FTP and P2P. Currently, there is no mechanism at the wireless AP to mitigate these effects except explicitly classifying the traffic based on port numbers or host IP addresses. We propose CHAP, a credit-based queue management technique, to eliminate the explicit configuration process and dynamically adjust the priority of all the flows from different devices to match their QoS requirements and wireless conditions to improve application quality in home networks. An analytical model is used to analyze the interaction between flows and credits and resulting queueing delays for packets. CHAP is evaluated using Network Simulator (NS2) under a wide range of conditions against First-In-First- Out (FIFO) and Strict Priority Queue (SPQ) scheduling algorithms. CHAP improves the quality of an online game, a VoIP session, a video streaming session, and a Web browsing activity by 20%, 3%, 93%, and 51%, respectively, compared to FIFO in the presence of an FTP download. CHAP provides these improvements similar to SPQ without an explicit classification of flows and a pre- configured scheduling policy. A Linux implementation of CHAP is used to evaluate its performance in a real residential network against FIFO. CHAP reduces the web response time by up to 85% compared to FIFO in the presence of a bulk file download. Our contributions include an analytic model for the credit-based queue management, simulation, and implementation of CHAP, which provides QoS with minimal configuration at the AP

Treatment-Based Classi?cation in Residential Wireless Access Points

IEEE 802.11 wireless access points (APs) act as the central communication hub inside homes, connecting all networked devices to the Internet. Home users run a variety of network applications with diverse Quality-of-Service requirements (QoS) through their APs. However, wireless APs are often the bottleneck in residential networks as broadband connection speeds keep increasing. Because of the lack of QoS support and complicated configuration procedures in most off-the-shelf APs, users can experience QoS degradation with their wireless networks, especially when multiple applications are running concurrently. This dissertation presents CATNAP, Classification And Treatment iN an AP , to provide better QoS support for various applications over residential wireless networks, especially timely delivery for real-time applications and high throughput for download-based applications. CATNAP consists of three major components: supporting functions, classifiers, and treatment modules. The supporting functions collect necessary flow level statistics and feed it into the CATNAP classifiers. Then, the CATNAP classifiers categorize flows along three-dimensions: response-based/non-response-based, interactive/non-interactive, and greedy/non-greedy. Each CATNAP traffic category can be directly mapped to one of the following treatments: push/delay, limited advertised window size/drop, and reserve bandwidth. Based on the classification results, the CATNAP treatment module automatically applies the treatment policy to provide better QoS support. CATNAP is implemented with the NS network simulator, and evaluated against DropTail and Strict Priority Queue (SPQ) under various network and traffic conditions. In most simulation cases, CATNAP provides better QoS supports than DropTail: it lowers queuing delay for multimedia applications such as VoIP, games and video, fairly treats FTP flows with various round trip times, and is even functional when misbehaving UDP traffic is present. Unlike current QoS methods, CATNAP is a plug-and-play solution, automatically classifying and treating flows without any user configuration, or any modification to end hosts or applications

IP Mobility in Wireless Operator Networks

Wireless network access is gaining increased heterogeneity in terms of the types of IP capable access technologies. The access network heterogeneity is an outcome of incremental and evolutionary approach of building new infrastructure. The recent success of multi-radio terminals drives both building a new infrastructure and implicit deployment of heterogeneous access networks. Typically there is no economical reason to replace the existing infrastructure when building a new one. The gradual migration phase usually takes several years. IP-based mobility across different access networks may involve both horizontal and vertical handovers. Depending on the networking environment, the mobile terminal may be attached to the network through multiple access technologies. Consequently, the terminal may send and receive packets through multiple networks simultaneously. This dissertation addresses the introduction of IP Mobility paradigm into the existing mobile operator network infrastructure that have not originally been designed for multi-access and IP Mobility. We propose a model for the future wireless networking and roaming architecture that does not require revolutionary technology changes and can be deployed without unnecessary complexity. The model proposes a clear separation of operator roles: (i) access operator, (ii) service operator, and (iii) inter-connection and roaming provider. The separation allows each type of an operator to have their own development path and business models without artificial bindings with each other. We also propose minimum requirements for the new model. We present the state of the art of IP Mobility. We also present results of standardization efforts in IP-based wireless architectures. Finally, we present experimentation results of IP-level mobility in various wireless operator deployments.Erilaiset langattomat verkkoyhteydet lisääntyvät Internet-kykyisten teknologioiden muodossa. Lukuisten eri teknologioiden päällekkäinen käyttö johtuu vähitellen ja tarpeen mukaan rakennetusta verkkoinfrastruktuurista. Useita radioteknologioita (kuten WLAN, GSM ja UMTS) sisältävien päätelaitteiden (kuten älypuhelimet ja kannettavat tietokoneet) viimeaikainen kaupallinen menestys edesauttaa uuden verkkoinfrastruktuurin rakentamista, sekä mahdollisesti johtaa verkkoteknologioiden kirjon lisääntymiseen. Olemassa olevaa verkkoinfrastruktuuria ei kaupallisista syistä kannata korvata uudella teknologialla yhdellä kertaa, vaan vaiheittainen siirtymävaihe kestää tyypillisesti useita vuosia. Internet-kykyiset päätelaitteet voivat liikkua joko saman verkkoteknologian sisällä tai eri verkkoteknologioiden välillä. Verkkoympäristöstä riippuen liikkuvat päätelaitteet voivat liittyä verkkoon useiden verkkoyhteyksien kautta. Näin ollen päätelaite voi lähettää ja vastaanottaa tietoliikennepaketteja yhtäaikaisesti lukuisia verkkoja pitkin. Tämä väitöskirja käsittelee Internet-teknologioiden liikkuvuutta ja näiden teknologioiden tuomista olemassa oleviin langattomien verkko-operaattorien verkkoinfrastruktuureihin. Käsiteltäviä verkkoinfrastruktuureita ei alun perin ole suunniteltu Internet-teknologian liikkuvuuden ja monien yhtäaikaisten yhteyksien ehdoilla. Tässä työssä ehdotetaan tulevaisuuden langattomien verkkojen arkkitehtuurimallia ja ratkaisuja verkkovierailujen toteuttamiseksi. Ehdotettu arkkitehtuuri voidaan toteuttaa ilman mittavia teknologisia mullistuksia. Mallin mukaisessa ehdotuksessa verkko-operaattorin roolit jaetaan selkeästi (i) verkko-operaattoriin, (ii) palveluoperaattoriin ja (iii) yhteys- sekä verkkovierailuoperaattoriin. Roolijako mahdollistaa sen, että kukin operaattorityyppi voi kehittyä itsenäisesti, ja että teennäiset verkkoteknologiasidonnaisuudet poistuvat palveluiden tuottamisessa. Työssä esitetään myös alustava vaatimuslista ehdotetulle mallille, esimerkiksi yhteysoperaattorien laatuvaatimukset. Väitöskirja esittelee myös liikkuvien Internet-teknologioiden viimeisimmän kehityksen. Työssä näytetään lisäksi standardointituloksia Internet-kykyisissä langattomissa arkkitehtuureissa

A Hybrid SDN-based Architecture for Wireless Networks

With new possibilities brought by the Internet of Things (IoT) and edge computing, the traffic demand of wireless networks increases dramatically. A more sophisticated network management framework is required to handle the flow routing and resource allocation for different users and services. By separating the network control and data planes, Software-defined Networking (SDN) brings flexible and programmable network control, which is considered as an appropriate solution in this scenario.Although SDN has been applied in traditional networks such as data centers with great successes, several unique challenges exist in the wireless environment. Compared with wired networks, wireless links have limited capacity. The high mobility of IoT and edge devices also leads to network topology changes and unstable link qualities. Such factors restrain the scalability and robustness of an SDN control plane. In addition, the coexistence of heterogeneous wireless and IoT protocols with distinct representations of network resources making it difficult to process traffic with state-of-the-art SDN standards such as OpenFlow. In this dissertation, we design a novel architecture for the wireless network management. We propose multiple techniques to better adopt SDN to relevant scenarios. First, while maintaining the centralized control plane logically, we deploy multiple SDN controller instances to ensure their scalability and robustness. We propose algorithms to determine the controllers\u27 locations and synchronization rates that minimize the communication costs. Then, we consider handling heterogeneous protocols in Radio Access Networks (RANs). We design a network slicing orchestrator enabling allocating resources across different RANs controlled by SDN, including LTE and Wi-Fi. Finally, we combine the centralized controller with local intelligence, including deploying another SDN control plane in edge devices locally, and offloading network functions to a programmable data plane. In all these approaches, we evaluate our solutions with both large-scale emulations and prototypes implemented in real devices, demonstrating the improvements in multiple performance metrics compared with state-of-the-art methods

Buffer De-bloating in Wireless Access Networks

PhDExcessive buffering brings a new challenge into the networks which is known as Bufferbloat, which is harmful to delay sensitive applications. Wireless access networks consist of Wi-Fi and cellular networks. In the thesis, the performance of CoDel and RED are investigated in Wi-Fi networks with different types of traffic. Results show that CoDel and RED work well in Wi-Fi networks, due to the similarity of protocol structures of Wi-Fi and wired networks. It is difficult for RED to tune parameters in cellular networks because of the time-varying channel. CoDel needs modifications as it drops the first packet of queue and the head packet in cellular networks will be segmented. The major contribution of this thesis is that three new AQM algorithms tailored to cellular networks are proposed to alleviate large queuing delays. A channel quality aware AQM is proposed using the CQI. The proposed algorithm is tested with a single cell topology and simulation results show that the proposed algorithm reduces the average queuing delay for each user by 40% on average with TCP traffic compared to CoDel. A QoE aware AQM is proposed for VoIP traffic. Drops and delay are monitored and turned into QoE by mathematical models. The proposed algorithm is tested in NS3 and compared with CoDel, and it enhances the QoE of VoIP traffic and the average endto- end delay is reduced by more than 200 ms when multiple users with different CQI compete for the wireless channel. A random back-off AQM is proposed to alleviate the queuing delay created by video in cellular networks. The proposed algorithm monitors the play-out buffer and postpones the request of the next packet. The proposed algorithm is tested in various scenarios and it outperforms CoDel by 18% in controlling the average end-to-end delay when users have different channel conditions

Protocolo de Transparência da mobilidade para redes Ad Hoc Móveis

Resumo: As redes Ad Hoc Moveis (Mobile Ad Hoc Networks (MANETs)) sao redes sem fio e sem uma infra-estrutura pré-existente. Elas possuem uma administração centralizada, sendo mantidas de modo autônomo e distribuído. Os nos podem se mover livremente pelo am-biente, criando uma topologia de rede dinômica, gerenciada e mantida por protocolos de roteamento distribuídos. As MANETs podem ser utilizadas em diferentes areas, entre elas, cita-se as redes espontôneas e como uma extensao da Internet, possibilitando maior mobilidade aos usuarios. Uma das características das MANETs e a mobilidade dos nos. O que, em alguns casos, acaba sendo um problema, pois a mobilidade degrada o desempenho do protocolo TCP e das aplicacoes utilizadas na Internet. Para que as aplicacães e o TCP possam funcionar adequadamente nas MANETs sao necessarias alteracoes nas implementações deles, o que demanda tempo e acarreta em custos adicionais no seu desenvolvimento e manutencao. Para possibilitar que as aplicacoes e os protocolos existentes possam ser utilizados sem alteracoes nas MANETs, propoe-se neste trabalho um protocolo capaz de deixar a mobilidade transparente, por meio de uma rede virtual fixa. O sistema proposto e denominado Protocolo Virtual de Transparência da Mobilidade (Virtual Transparent Mobility Protocol (VTMP)). O VTMP atua entre os protocolos de roteamento e de transporte, sem alterar a implementacao de nenhum deles, recebendo os pacotes da camada de transporte e encaminhando-os por meio da rede virtual fixa, criada sobre a rede real móvel. O objetivo do VTMP e permitir que o TCP possa funcionar sobre a rede movel sem qualquer alteracao, possibilitando que qualquer aplicacao tradicional que use o TCP tambem possa ser utilizada sem alteracoes. Neste trabalho, o VTMP foi implementado e avaliado em diferentes ambientes e condições de trafego

Open Platforms for Connected Vehicles

L'abstract è presente nell'allegato / the abstract is in the attachmen

Mobility management in IP-Based Networks

Mobile communication networks experience a tremendous development clearly evident from the wide variety of new applications way beyond classical phone services. The tremendous success of the Internet along with the demand for always-on connectivity has triggered the development of All-IP mobile communication networks. Deploying these networks requires, however, overcoming many challenges. One of the main challenges is how to manage the mobility between cells connecting through an IP core in a way that satisfies real-time requirements. This challenge is the focus of this dissertation. This dissertation delivers an in-depth analysis of the mobility management issue in IP-based mobile communication networks. The advantages and disadvantages of various concepts for mobility management in different layers of the TCP/IP protocol stack are investigated. In addition, a classification and brief description of well-known mobility approaches for each layer are provided. The analysis concludes that network layer mobility management solutions seem to be best suited to satisfy the requirements of future All-IP networks. The dissertation, therefore, provides a comprehensive review of network layer mobility management protocols along with a discussion of their pros and cons. Analyses of previous work in this area show that the proposed techniques attempt to improve the performance by making constraints either on access networks (e.g. requiring a hierarchical topology, introducing of intermediate nodes, etc.) or mobile terminals (e.g. undertaking many measurements, location tracking, etc.). Therefore, a new technique is required that completes handoffs quickly without affecting the end-to-end performance of ongoing applications. In addition, it should place restrictions neither on access networks nor on mobiles. To meet these requirements, a new solution named Mobile IP Fast Authentication protocol (MIFA) is proposed. MIFA provides seamless mobility and advances the state of the art. It utilizes the fact that mobiles movements are limited to a small set of neighboring subnets. Thus, contacting these neighbors and providing them in advance with sufficient data related to the mobiles enable them to fast re-authenticate the mobiles after the handoff. The dissertation specifies the proposal for both IPv4 and IPv6. The specification of MIFA considers including many error recovery mechanisms to cover the most likely failures. Security considerations are studied carefully as well. MIFA does not make any restrictions on the network topology. It makes use of layer 2 information to optimize the performance and works well even if such information is not available.In order to analyze our new proposal in comparison to a wide range of well-known mobility management protocols, this dissertation proposes a generic mathematical model that supports the evaluation of figures such as average handoff latency, average number of dropped packets, location update cost and packet delivery cost. The generic model considers dropped control messages and takes different network topologies and mobility scenarios into account. This dissertation also validates the generic mathematical model by comparing its results to simulation results as well as results of real testbeds under the same assumptions. The validation proves that the generic model delivers an accurate evaluation of the performance in low-loaded networks. The accuracy of the model remains acceptable even under high loads. The validation also shows that simulation results lie in a range of 23 %, while results of real testbeds lie in a range of 30 % of the generic model?s results. To simplify the analysis using the generic mathematical model, 4 new tools are developed in the scope of this work. They automate the parameterization of mobility protocols, network topologies and mobility scenarios. This dissertation also evaluates the new proposal in comparison to well-known approaches (e.g. Mobile IP, Handoff-Aware Wireless Access Internet Infrastructure (HAWAII), etc.) by means of the generic mathematical model as well as simulation studies modeled in the Network Simulator 2. The evaluation shows that MIFA is a very fast protocol. It outperforms all studied protocols with respect to the handoff latency and number of dropped packets per handoff. MIFA is suitable for low as well as high speeds. Moreover, there is no significant impact of the network topology on its performance. A main advantage of MIFA is its robustness against the dropping of control messages. It remains able to achieve seamless handoffs even if a dropping occurs. The performance improvement is achieved, however, at the cost of introducing new control messages mainly to distribute data concerning mobile terminals to neighbor subnets. This results in more location update cost than that resulting from the other mobility management protocols studied. Due to excluding any constraints on the network topology, MIFA generates the same packet delivery cost as Mobile IP and less than other protocols.An additional focus of this dissertation is the development of an adaptive eLearning environment that personalizes eLearning contents conveying the topics of this dissertation depending on users? characteristics. The goal is to allow researchers to quickly become involved in research on mobility management, while learners such as students are able to gain information on the topics without excess detail. Analyses of existing eLearning environments show a lack of adaptivity support. Existing environments focus mainly on adapting either the navigation or the presentation of contents depending on one or more selected users? characteristics. There is no environment that supports both simultaneously. In addition, many user characteristics are disregarded during the adaptivity process. Thus, there is a need to develop a new adaptive eLearning environment able to eliminate these drawbacks. This dissertation, therefore, designs a new Metadata-driven Adaptive eLearning Environment (MAeLE). MAeLE generates personalized eLearning courses along with building an adequate navigation at run-time. Adaptivity depends mainly on providing contents with their describing metadata, which are stored in a separate database, thus enabling reusing of eLearning contents. The relation between the metadata that describe contents and those describing learners are defined accurately, which enables a dynamic building of personalized courses at run-time. A prototype for MAeLE is provided in this dissertation as well

Shortest Route at Dynamic Location with Node Combination-Dijkstra Algorithm

Abstract— Online transportation has become a basic requirement of the general public in support of all activities to go to work, school or vacation to the sights. Public transportation services compete to provide the best service so that consumers feel comfortable using the services offered, so that all activities are noticed, one of them is the search for the shortest route in picking the buyer or delivering to the destination. Node Combination method can minimize memory usage and this methode is more optimal when compared to A* and Ant Colony in the shortest route search like Dijkstra algorithm, but can’t store the history node that has been passed. Therefore, using node combination algorithm is very good in searching the shortest distance is not the shortest route. This paper is structured to modify the node combination algorithm to solve the problem of finding the shortest route at the dynamic location obtained from the transport fleet by displaying the nodes that have the shortest distance and will be implemented in the geographic information system in the form of map to facilitate the use of the system. Keywords— Shortest Path, Algorithm Dijkstra, Node Combination, Dynamic Location (key words

Cognitive Hyperconnected Digital Transformation

Cognitive Hyperconnected Digital Transformation provides an overview of the current Internet of Things (IoT) landscape, ranging from research, innovation and development priorities to enabling technologies in a global context. It is intended as a standalone book in a series that covers the Internet of Things activities of the IERC-Internet of Things European Research Cluster, including both research and technological innovation, validation and deployment. The book builds on the ideas put forward by the European Research Cluster, the IoT European Platform Initiative (IoT-EPI) and the IoT European Large-Scale Pilots Programme, presenting global views and state-of-the-art results regarding the challenges facing IoT research, innovation, development and deployment in the next years. Hyperconnected environments integrating industrial/business/consumer IoT technologies and applications require new IoT open systems architectures integrated with network architecture (a knowledge-centric network for IoT), IoT system design and open, horizontal and interoperable platforms managing things that are digital, automated and connected and that function in real-time with remote access and control based on Internet-enabled tools. The IoT is bridging the physical world with the virtual world by combining augmented reality (AR), virtual reality (VR), machine learning and artificial intelligence (AI) to support the physical-digital integrations in the Internet of mobile things based on sensors/actuators, communication, analytics technologies, cyber-physical systems, software, cognitive systems and IoT platforms with multiple functionalities. These IoT systems have the potential to understand, learn, predict, adapt and operate autonomously. They can change future behaviour, while the combination of extensive parallel processing power, advanced algorithms and data sets feed the cognitive algorithms that allow the IoT systems to develop new services and propose new solutions. IoT technologies are moving into the industrial space and enhancing traditional industrial platforms with solutions that break free of device-, operating system- and protocol-dependency. Secure edge computing solutions replace local networks, web services replace software, and devices with networked programmable logic controllers (NPLCs) based on Internet protocols replace devices that use proprietary protocols. Information captured by edge devices on the factory floor is secure and accessible from any location in real time, opening the communication gateway both vertically (connecting machines across the factory and enabling the instant availability of data to stakeholders within operational silos) and horizontally (with one framework for the entire supply chain, across departments, business units, global factory locations and other markets). End-to-end security and privacy solutions in IoT space require agile, context-aware and scalable components with mechanisms that are both fluid and adaptive. The convergence of IT (information technology) and OT (operational technology) makes security and privacy by default a new important element where security is addressed at the architecture level, across applications and domains, using multi-layered distributed security measures. Blockchain is transforming industry operating models by adding trust to untrusted environments, providing distributed security mechanisms and transparent access to the information in the chain. Digital technology platforms are evolving, with IoT platforms integrating complex information systems, customer experience, analytics and intelligence to enable new capabilities and business models for digital business