Heterogeneous Wireless Networks QoE Framework

With the appearance of small cells and the move of mobile networks towards an all-IP 4G network, the convergence of these with Wi-Fi becomes a possibility which at the same time opens the path to achieve what will become 5G connectivity. This thesis describes the evolution of the different mainstream wireless technologies deployed around the world and how they can interact, and provides tools to use this convergence to achieve the foreseen requirements expected in a 5G environment and the ideal user experience. Several topics were identified as needing attention: handover between heterogeneous networks, security of large numbers of small cells connected via a variety of backhaul technologies to the core networks, edge content distribution to improve latency, improvement of the service provided in challenging radio environments and interference between licensed and unlicensed spectrum. Within these topics a contribution was made to improve the current status by analysing the unaddressed issues and coming up with potential improvements that were tested in trials or lab environment. The main contributions from the study have been: 1. A patent in the wireless security domain that reuses the fact that overlapping coverage is and will be available and protects against man in the middle attacks (Section 5.3). 2. A patent in the content distribution domain that manages to reduce the cost to deliver content within a mobile network by looking for the shortest path to the requested content (Section 6.3). 3. Improvements and interoperability test of 802.21 standard which improves the seamlessness of handovers (Section 4.2). 4. 2 infill trials which focus on how to improve the user experience in those challenging conditions (Sections 7.2 and 7.3). 5. An interference study with Wi-Fi 2.4GHz for the newly allocated spectrum for 4G (Section 8.2). This thesis demonstrates some of the improvements required in current wireless networks to evolve towards 5G and achieve the coverage, service, user experience, latency and security requirements expected from the next generation mobile technology

Automotive Cognitive Access: Towards customized vehicular communication system

The evolution of Software Defined Networking (SDN) and Virtualization of mobile Network Functions (NFV) have enabled the new ways of managing mobile access systems and are seen as a major technological foundation of the Fifth Generation (5G) of mobile networks. With the appearance of 5G specifications, the mobile system architecture has the transition from a network of entities to a network of functions. This paradigm shift led to new possibilities and challenges. Existing mobile communication systems rely on closed and inflexible hardware-based architectures both at the access and core network. It implies significant challenges in implementing new techniques to maximize the network capacity, scalability and increasing performance for diverse data services. This work focuses preliminary on the architectural evolutions needed to solve challenges perceived for the next generation of mobile networks. I consider Software defined plus Virtualization featured Mobile Network (S+ MN) architecture as a baseline reference model, aiming at the further improvements to support the access requirements for diverse user groups. I consider an important class of things, vehicles, which needs efficient mobile internet access at both the system and application levels. I identify and describe key requirements of emerging vehicular communications and assess existing standards to determine their limitations. To provide optimized wireless communications for the specific user group, the 5G systems come up with network slicing as a potential solution to create customized networks. Network slicing has the capability to facilitates dynamic and efficient allocation of network resources and support diverse service scenarios and services. A network slice can be broadly defined as an end-to-end logically isolated network that includes end devices as well as access and core network functions. To this effect, I describe the enhanced behaviour of S+ MN architecture for the collection of network resources and details the potential functional grouping provided by S+ MN architecture that paves the way to support automotive slicing. The proposed enhancements support seamless connection mobility addressing the automotive access use case highly mobile environment. I follow the distribution of gateway functions to solve the problem of unnecessary long routes and delays. Exploiting the open SDN capabilities, the proposed S+ NC is able to parallelize the execution of certain control plane messages thus enabling the signalling optimisation. Furthermore, it enables the (Re)selection of efficient data plane paths with implied upper-layer service continuity mechanisms that remove the chains of IP address preservation for session continuity during IP anchor relocation. An implementation setup validates the proposed evolutions, including its core functionalities implemented using the ns-3 network simulator. The proposed slicing scheme has been evaluated through a number of scenarios such as numbers of signalling messages processed by control entities for an intersystem handover procedure relative to current mobile network architecture. I also perform the performance improvement analysis based on simulation results. Furthermore, I experimentally prove the feasibility of using Multipath TCP for connection mobility in intersystem handover scenario. The experiments run over the Linux Kernel implementation of Multipath TCP developed over the last years. I extend the Multipath TCP path management to delegates the management of the data paths according to the application needs. The implementation results have shown that the proposed S+ MN slicing architecture and enhancements achieve benefits in multiple areas, for example improving the mobility control and management, maintaining QoS, smooth handover, session continuity and efficient slice management and orchestration

Improving initiation, decision and execution phases for vertical handover in heterogeneous wireless mobile networks

One of the challenging issues in Next Generation Wireless Systems (NGWS) is seamless Vertical Handover (VHO) during the mobility between different types of technologies (3GPP and non-3GPP) such as Global System for Mobile Communication (GSM), Wireless Fidelity (Wi-Fi), Worldwide Interoperability for Microwave Access (WiMAX), Universal Mobile Telecommunications System (UMTS) and Long Term Evolution (LTE). Therefore, the telecommunication operators are required to develop aninteroperability strategy for these different types of existing networks to get the best connection anywhere, anytime without interruption of the ongoing sessions. In order to identify this problem accurately, the research study presented in this thesis provides four surveys about VHO approaches found in the literature. In these surveys, we classify the existing VHO approaches into categories based on the available VHO techniques for which we present their objectives and performances issues. After that, we propose an optimised VHO approach based on the VHO approaches that have been studied in the literature and take into consideration the research problems and conclusions which arearisen in our surveys. The proposed approach demonstrates better performance (packet loss, latency and signaling cost), less VHO connection failure (probability of minimising VHO reject sessions), less complexity and an enhanced VHO compared with that foundin the literature. It consists of a procedure which is implemented by an algorithm. The proposed procedure of loose coupling and Mobile Internet Protocol version 4 (MIPv4) provides early buffering for new data packets to minimise VHO packet loss and latency. Analysis and simulation of the proposed procedure show that the VHO packet loss and latency are significantly reduced compared with previous MIPv6 procedures found in the literature.The proposed algorithm is composed of two main parts: Handover Initiation and Optimum Radio Access Technologies (RATs) list of priority. The first part includes two main types of VHO and gives priority to imperative sessions over alternative sessions. IIIThis part is also responsible for deciding when and where to perform the handover by choosing the best RATs from the multiple ones available. Then, it passes them to the decision phase. This results in reducing the signaling cost and the inevitable degradation in Quality of Service (QoS) as a result of avoiding unnecessary handover processes. The second part defines RATs list of priority to minimise VHO connection failure. Analysis and simulation based performance evaluations then demonstrate that the proposed algorithm outperforms the traditional algorithms in terms of: (a) the probability of VHOconnection failure as a result of using the optimum RATs list of priority and (b) thesignaling cost and the inevitable degradation in QoS as a result of avoiding unnecessary handover processes

SDN-DMM for intelligent mobility management in heterogeneous mobile IP networks

[EN] Mobility management applied to the traditional architecture of the Internet has become a great challenge because of the exponential growth in the number of devices that can connect to the network. This article proposes a Software-Defined Networking (SDN)-based architecture, called SDN-DMM (SDN-Distributed Mobility Management), that deals with the distributed mode of mobility management in heterogeneous access networks in a simplified and efficient way, ensuring mainly the continuity of IP sessions. Intent-based mobility management with an IP mapping schema for mobile node identification offers optimized routing without tunneling techniques, hence, an efficient use of the network infrastructure. The simplified mobility control API reduces both signaling and handover latency costs and provides a better scalability and performance in comparison with traditional and SDN-based DMM approaches. An analytical evaluation of such costs demonstrated the better performance of SDN-DMM, and a proof of concept of the proposal was implemented in a real environment.CAPES (Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior) - Brasil; Secretaria de Estado de Investigacion, Desarrollo e Innovacion, Grant/Award Number: TIN2017-84802-C2-1-P; "Convocatoria 2017 - Proyectos I+D+I Programa Estatal de Investigacion, Desarrollo e Innovacion, convocatoria excelencia", Grant/Award Number: TIN2017-84802-C2-1-P; FAP-DF ("Fundacao de Apoio a Pesquisa do Distrito Federal")-BrazilTorres Cordova, R.; Gondim, PRL.; Llerena, YP.; Lloret, J. (2019). SDN-DMM for intelligent mobility management in heterogeneous mobile IP networks. International Journal of Communication Systems. 32(17):1-31. https://doi.org/10.1002/dac.4140131321

Network-driven handover in 5G

Currently, users’ expectations regarding technological performance are constantly increasing. An example of this is the growing consumption of multimedia content via the Internet. Multimedia applications with a variable number of users/requests have variable demand over time that may expose the limitation of the network channels. This may cause a problem of demand mobility generated by the service/application. Each generation of mobile networks has specific handover processes, which in the case of 4G can be controlled according to the applications requirements, with the possibility of multiconnectivity. This process was massified in 5G. The main contribution of this dissertation is the development and analysis of decision models for controlling the video streaming and user association to a BS in the network architecture. The scenario considered refers to a football stadium with multiple points of view – video streams – that each spectator can request to view on their cell phone or tablet. The developed simulator models the stadium scenario using a combination of services, which occur on the 5G network. Vertical handover generated by the network is used,aidedbynetworkslicing. Thenetworkslicingactsinthepartofthebandwidthdivision between the different antennas and allows the throughput of the different broadcast (FeMBMS)channelsto becontrolledbytheservice -theradionetworkcapacitylimitsthe throughput. The results obtained in a case of 80000 spectators who select different beams over time, considering8basestations(BS),showthatthequalityofexperienceishighonlywhenthe handover and the control of beam diffusion by BS are managed according to the application requirements. The network recovers from huge peaks by handling as many requests at once as possible. Instead of the user only getting the steam in a good quality or not getting it at all, the network performs a best-effort solution of downgrading the quality of multicasting in order to expend less resources with the same quantity of requests. The network state is taken into consideration. Although there are load peaks on the network, it is never congested.Atualmente, as expectativas dos utilizadores em relação à capacidade tecnológica não param de aumentar. Exemplo disso é o crescente consumo de conteúdo multimédia através da Internet. Aplicações multimédia com número variável de utilizadores e pedidos têm um fluxo de serviço variável ao longo do tempo. Esta variância pode expor a limitação de canais de rede, que consequentemente pode causar um problema de mobilidade gerado pelo serviço/aplicação. Cada geração de redes móveis possui processos de handover de utilizadores específicos, que no caso da geração 4G passou a ser controlado em função das aplicações, com a possibilidade de multiconectividade. Este processo foi massificado no 5G. A principal contribuição desta dissertação é o desenvolvimento e análise de modelos de decisão para controlar a difusão de vídeo e a associação de utilizadores à rede rádio na arquitetura da rede. O cenário considerado reflete um estádio de futebol com vários pontos de vista - diferentes feixes de vídeo - que cada espectador pode solicitar e visualizar no seu telemóvel ou tablet. O simulador desenvolvido modela o cenário do estádio usando uma combinação de serviços, que ocorrem na rede 5G. É usado handover vertical gerado pela rede auxiliado por network slicing que atua na parte da divisão da largura de banda entre as diferentes antenas e permite que a taxa de débito dos diferentes canais de difusão (FeMBMS) seja controlada pelo serviço - a capacidade da rede rádio limita a taxa de transferência. Os resultados obtidos no caso de 80000 espectadores que selecionam diferentes feixes ao longo do tempo, considerando 8 estações base (BS), mostram que a qualidade de experiência somente é elevada quando o handover e o controlo da difusão de feixes pelas BS são geridos de acordo com os requisitos da aplicação. A rede recupera a estabilidade após enormes picos de transferência gerindo os seus recursos. Em vez do utilizador ser prejudicado na totalidade quando a rede não tem recursos e ser privado de obter serviço, é utilizado um processo alternativo em que a rede diminui a qualidade de multicasting, gastando menos recursos com a mesma quantidade de pedidos. O estado da rede é sempre tido em consideração - embora hajam picos de carga na rede, esta nunca fica congestionada

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

Context-awareness for ubiquitous media service delivery in next generation networks

Les récentes avancées technologiques permettent désormais la fabrication de terminaux mobiles de plus en plus compacts et dotés de plusieurs interfaces réseaux. Le nouveau modèle de consommation de médias se résume par le concept "Anytime, Anywhere, Any Device" et impose donc de nouvelles exigences en termes de déploiement de services ubiquitaires. Cependant la conception et le developpement de réseaux ubiquitaires et convergents de nouvelles générations soulèvent un certain nombre de défis techniques. Les standards actuels ainsi que les solutions commerciales pourraient être affectés par le manque de considération du contexte utilisateur. Le ressenti de l'utilisateur concernant certains services multimédia tels que la VoIP et l'IPTV dépend fortement des capacités du terminal et des conditions du réseau d'accès. Cela incite les réseaux de nouvelles générations à fournir des services ubiquitaires adaptés à l'environnement de l'utilisateur optimisant par la même occasion ses resources. L'IP Multimedia Subsystem (IMS) est une architecture de nouvelle génération qui centralise l'accès aux services et permet la convergence des réseaux fixe/mobile. Néanmoins, l'évolution de l'IMS est nécessaire sur les points suivants :- l'introduction de la sensibilité au contexte utilisateur et de la PQoS (Perceived QoS) : L'architecture IMS ne prend pas en compte l'environnement de l'utilisateur, ses préférences et ne dispose pas d'un méchanisme de gestion de PQOS. Pour s'assurer de la qualité fournit à l'utilisateur final, des informations sur l'environnement de l'utilisateur ainsi que ses préférences doivent transiter en cœur de réseau afin d'y être analysés. Ce traitement aboutit au lancement du service qui sera adapté et optimisé aux conditions observées. De plus pour le service d'IPTV, les caractéristiques spatio-temporelles de la vidéo influent de manière importante sur la PQoS observée côté utilisateur. L'adaptation des services multimédias en fonction de l'évolution du contexte utilisateur et de la nature de la vidéo diffusée assure une qualité d'expérience à l'utilisateur et optimise par la même occasion l'utilisation des ressources en cœur de réseau.- une solution de mobilité efficace pour les services conversationnels tels que la VoIP : Les dernières publications 3GPP fournissent deux solutions de mobilité: le LTE proposeMIP comme solution de mobilité alors que l'IMS définit une mobilité basée sur le protocoleapplicatif SIP. Ces standards définissent le système de signalisation mais ne s'avancent pas sur la gestion du flux média lors du changement d'interface réseau. La deuxième section introduit une étude comparative détaillée des solutions de mobilité dans les NGNs.Notre première contribution est la spécification de l'architecture globale de notre plateforme IMS sensible au contexte utilisateur réalisée au sein du projet Européen ADAMANTIUM. Nous détaillons tout d'abord le serveur MCMS intelligent placé dans la couche application de l'IMS. Cet élément récolte les informations de qualité de services à différents équipements réseaux et prend la décision d'une action sur l'un de ces équipements. Ensuite nous définissons un profil utilisateur permettant de décrire son environnement et de le diffuser en coeur de réseau. Une étude sur la prédiction de satisfaction utilisateur en fonction des paramètres spatio-temporels de la vidéo a été réalisée afin de connaître le débit idéal pour une PQoS désirée.Notre deuxième contribution est l'introduction d'une solution de mobilité adaptée aux services conversationnels (VoIP) tenant compte du contexte utilisateur. Notre solution s'intègre à l'architecture IMS existante de façon transparente et permet de réduire le temps de latence du handover. Notre solution duplique les paquets de VoIP sur les deux interfaces actives pendant le temps de la transition. Parallèlement, un nouvel algorithme de gestion de mémoire tampon améliore la qualité d'expérience pour le service de VoIP.The latest advances in technology have already defied Moore s law. Thanks to research and industry, hand-held devices are composed of high processing embedded systems enabling the consumption of high quality services. Furthermore, recent trends in communication drive users to consume media Anytime, Anywhere on Any Device via multiple wired and wireless network interfaces. This creates new demands for ubiquitous and high quality service provision management. However, defining and developing the next generation of ubiquitous and converged networks raise a number of challenges. Currently, telecommunication standards do not consider context-awareness aspects for network management and service provisioning. The experience felt by the end-user consuming for instance Voice over IP (VoIP) or Internet Protocol TeleVision (IPTV) services varies depending mainly on user preferences, device context and network resources. It is commonly held that Next Generation Network (NGN) should deliver personalized and effective ubiquitous services to the end user s Mobile Node (MN) while optimizing the network resources at the network operator side. IP Multimedia Subsystem (IMS) is a standardized NGN framework that unifies service access and allows fixed/mobile network convergence. Nevertheless IMS technology still suffers from a number of confining factors that are addressed in this thesis; amongst them are two main issues :The lack of context-awareness and Perceived-QoS (PQoS):-The existing IMS infrastructure does not take into account the environment of the user ,his preferences , and does not provide any PQoS aware management mechanism within its service provisioning control system. In order to ensure that the service satisfies the consumer, this information need to be sent to the core network for analysis. In order to maximize the end-user satisfaction while optimizing network resources, the combination of a user-centric network management and adaptive services according to the user s environment and network conditions are considered. Moreover, video content dynamics are also considered as they significantly impact on the deduced perceptual quality of IPTV services. -The lack of efficient mobility mechanism for conversational services like VoIP :The latest releases of Third Generation Partnership Project (3GPP) provide two types of mobility solutions. Long-Term Evolution (LTE) uses Mobile IP (MIP) and IMS uses Session Initiation Protocol (SIP) mobility. These standards are focusing on signaling but none of them define how the media should be scheduled in multi-homed devices. The second section introduces a detailed study of existing mobility solutions in NGNs. Our first contribution is the specification of the global context-aware IMS architecture proposed within the European project ADAptative Management of mediA distributioN based on saTisfaction orIented User Modeling (ADAMANTIUM). We introduce the innovative Multimedia Content Management System (MCMS) located in the application layer of IMS. This server combines the collected monitoring information from different network equipments with the data of the user profile and takes adaptation actions if necessary. Then, we introduce the User Profile (UP) management within the User Equipment (UE) describing the end-user s context and facilitating the diffusion of the end-user environment towards the IMS core network. In order to optimize the network usage, a PQoS prediction mechanism gives the optimal video bit-rate according to the video content dynamics. Our second contribution in this thesis is an efficient mobility solution for VoIP service within IMS using and taking advantage of user context. Our solution uses packet duplication on both active interfaces during handover process. In order to leverage this mechanism, a new jitter buffer algorithm is proposed at MN side to improve the user s quality of experience. Furthermore, our mobility solution integrates easily to the existing IMS platform.BORDEAUX1-Bib.electronique (335229901) / SudocSudocFranceF

Access network selection schemes for multiple calls in next generation wireless networks

There is an increasing demand for internet services by mobile subscribers over the wireless access networks, with limited radio resources and capacity constraints. A viable solution to this capacity crunch is the deployment of heterogeneous networks. However, in this wireless environment, the choice of the most appropriate Radio Access Technology (RAT) that can Tsustain or meet the quality of service (QoS) requirements of users' applications require careful planning and cost efficient radio resource management methods. Previous research works on access network selection have focused on selecting a suitable RAT for a user's single call request. With the present request for multiple calls over wireless access networks, where each call has different QoS requirements and the available networks exhibit dynamic channel conditions, the choice of a suitable RAT capable of providing the "Always Best Connected" (ABC) experience for the user becomes a challenge. In this thesis, the problem of selecting the suitable RAT that is capable of meeting the QoS requirements for multiple call requests by mobile users in access networks is investigated. In addressing this problem, we proposed the use of Complex PRoprtional ASsesment (COPRAS) and Consensus-based Multi-Attribute Group Decision Making (MAGDM) techniques as novel and viable RAT selection methods for a grouped-multiple call. The performance of the proposed COPRAS multi-attribute decision making approach to RAT selection for a grouped-call has been evaluated through simulations in different network scenarios. The results show that the COPRAS method, which is simple and flexible, is more efficient in the selection of appropriate RAT for group multiple calls. The COPRAS method reduces handoff frequency and is computationally inexpensive when compared with other methods such as the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), Simple Additive Weighting (SAW) and Multiplicative Exponent Weighting (MEW). The application of the proposed consensus-based algorithm in the selection of a suitable RAT for group-multiple calls, comprising of voice, video-streaming, and file-downloading has been intensively investigated. This algorithm aggregates the QoS requirement of the individual application into a collective QoS for the group calls. This new and novel approach to RAT selection for a grouped-call measures and compares the consensus degree of the collective solution and individual solution against a predefined threshold value. Using the methods of coincidence among preferences and coincidence among solutions with a predefined consensus threshold of 0.9, we evaluated the performance of the consensus-based RAT selection scheme through simulations under different network scenarios. The obtained results show that both methods of coincidences have the capability to select the most suitable RAT for a group of multiple calls. However, the method of coincidence among solutions achieves better results in terms of accuracy, it is less complex and the number of iteration before achieving the predefined consensus threshold is reduced. A utility-based RAT selection method for parallel traffic-streaming in an overlapped heterogeneous wireless network has also been developed. The RAT selection method was modeled with constraints on terminal battery power, service cost and network congestion to select a specified number of RATs that optimizes the terminal interface utility. The results obtained show an optimum RAT selection strategy that maximizes the terminal utility and selects the best RAT combinations for user's parallel-streaming for voice, video and file-download