Analyses and design of a new integrated mobile SIP proxy to enhance the scalability in mobile network operators

The emergence of the two new technologies, namely Software Defined Network (SDN) and Network Function Virtualization (NFV) have radically changed the development of computer network fun etions and the evolution of mobile network operators (MN Os) infrastructures. The se two technologies bring to MN Os the promises of reducing costs, enhancing network flexibility and scalability to handle the growth in the number of mobile users and the need to extend its coverage to rural areas. The aim of this thesis 1s to exploit the advantages of the NFV concept to support the implementation of full y integrated solution with an external Session Initial Protocol (SIP) proxy application to enhance the scalability in MN Os. The proposed solution offers a hosted SIP proxy application installed on a virtual machine (VM) environment. The SIP proxy provides full Private Branch Exchange (PBX) and Switch (SW) functionality with Interactive Voice Response (IVR) capabilities. It maximizes the capacity in the existing servers and value-added services (VAS) data centers within the MNOs. The proposed solution enhances the usage of the existing bandwidth by using the unlicensed radio frequency (RF) spectrum bandwidth instead of the licensed RF spectrum to support a larger number of smartphones and data plans. In the initial experimental testbed, TeleFinity IP PBX, which is an external SIP proxy, 1s deployed on a virtual platform and integrated with the mobile network. The integration 1s realized by establishing a point to point protocol (PPP) SIP trunk connection between TeleFinity IP PBX and the Gateway Mobile Switch Center (GMSC). Severa! Testing scenarios were carried out over a local area network (LAN) and a wide area network (W AN) using different voice codees: G.711 u-law, G. 723, and G. 729 to validate the voice cali quality offered by the proposed solution. The Network analyzer software solutions: 1) Startrinity SIP tester, 2) Commview and 3) Resource Monitor are used to measure severa! Quality of Service (QoS) metrics. These include voice jitter, delay, packet Joss, and MOS. This procedure ensures that the proposed solution can handle voice communications with acceptable quality compared to LTE standards

An investigation into the readiness of open source software to build a Telco Cloud for virtualising network functions

Cloud computing offers new mechanisms that change the way networks can be created and managed. The increased demand for multimedia and Internet of Things (IoT) services using the Internet Protocol is also fueling the need to look more into a networking approach that is less reliant on physical hardware components and allows new networks and network components to be created on-demand. Network Function Virtualisation (NFV) is a networking paradigm that decouples network functions from the hardware on which they run on. This offers new approaches to telecommunication providers who are looking to new ways of improving Quality of Service (QoS) in cost effective ways. Cloud technologies have given way to more specialised cloud environments such as the telco cloud. The telco cloud is a cloud environment where telecommunication services are hosted utilising NFV techniques. As the use of telecommunication standards moves towards 5G, network services will be provided in a virtualised manner in order to keep up with the demand. Open source software is a driver for innovation as it is has a collaborative culture to support it. This research investigates the readiness of open source tools to build a telco cloud that supports functions such as autoscaling and fault tolerance. Currently available open source software was explored for the different aspects involved in building a cloud from the ground up. The ETSI NFV MANO framework is also discussed as it is a widely used guiding standard for implementing NFV. Guided by the ETSI NFV MANO framework, open source software was used in an experiment to build a resilient cloud environment in which a virtualised IP Multimedia Subsystem (vIMS) network was deployed. Through this experimentation, it is evident that open source tools are mature enough to build the cloud environment and its ETSI NFV MANO compliant orchestration. However, features such as autoscaling and fault tolerance are still fairly immature and experimental

Optimizing IETF multimedia signaling protocols and architectures in 3GPP networks : an evolutionary approach

Signaling in Next Generation IP-based networks heavily relies in the family of multimedia signaling protocols defined by IETF. Two of these signaling protocols are RTSP and SIP, which are text-based, client-server, request-response signaling protocols aimed at enabling multimedia sessions over IP networks. RTSP was conceived to set up streaming sessions from a Content / Streaming Server to a Streaming Client, while SIP was conceived to set up media (e.g.: voice, video, chat, file sharing, …) sessions among users. However, their scope has evolved and expanded over time to cover virtually any type of content and media session. As mobile networks progressively evolved towards an IP-only (All-IP) concept, particularly in 4G and 5G networks, 3GPP had to select IP-based signaling protocols for core mobile services, as opposed to traditional SS7-based protocols used in the circuit-switched domain in use in 2G and 3G networks. In that context, rather than reinventing the wheel, 3GPP decided to leverage Internet protocols and the work carried on by the IETF. Hence, it was not surprise that when 3GPP defined the so-called Packet-switched Streaming Service (PSS) for real-time continuous media delivery, it selected RTSP as its signaling protocol and, more importantly, SIP was eventually selected as the core signaling protocol for all multimedia core services in the mobile (All-)IP domain. This 3GPP decision to use off-the-shelf IETF-standardized signaling protocols has been a key cornerstone for the future of All-IP fixed / mobile networks convergence and Next Generation Networks (NGN) in general. In this context, the main goal of our work has been analyzing how such general purpose IP multimedia signaling protocols are deployed and behave over 3GPP mobile networks. Effectively, usage of IP protocols is key to enable cross-vendor interoperability. On the other hand, due to the specific nature of the mobile domain, there are scenarios where it might be possible to leverage some additional “context” to enhance the performance of such protocols in the particular case of mobile networks. With this idea in mind, the bulk of this thesis work has consisted on analyzing and optimizing the performance of SIP and RTSP multimedia signaling protocols and defining optimized deployment architectures, with particular focus on the 3GPP PSS and the 3GPP Mission Critical Push-to-Talk (MCPTT) service. This work was preceded by a detailed analysis work of the performance of underlying IP, UDP and TCP protocol performance over 3GPP networks, which provided the best baseline for the future work around IP multimedia signaling protocols. Our contributions include the proposal of new optimizations to enhance multimedia streaming session setup procedures, detailed analysis and optimizations of a SIP-based Presence service and, finally, the definition of new use cases and optimized deployment architectures for the 3GPP MCPTT service. All this work has been published in the form of one book, three papers published in JCR cited International Journals, 5 articles published in International Conferences, one paper published in a National Conference and one awarded patent. This thesis work provides a detailed description of all contributions plus a comprehensive overview of their context, the guiding principles beneath all contributions, their applicability to different network deployment technologies (from 2.5G to 5G), a detailed overview of the related OMA and 3GPP architectures, services and design principles. Last but not least, the potential evolution of this research work into the 5G domain is also outlined as well.Els mecanismes de Senyalització en xarxes de nova generació es fonamenten en protocols de senyalització definits per IETF. En particular, SIP i RTSP són dos protocols extensibles basats en missatges de text i paradigma petició-resposta. RTSP va ser concebut per a establir sessions de streaming de continguts, mentre SIP va ser creat inicialment per a facilitar l’establiment de sessions multimèdia (veu, vídeo, xat, compartició) entre usuaris. Tot i així, el seu àmbit d’aplicació s’ha anat expandint i evolucionant fins a cobrir virtualment qualsevol tipus de contingut i sessió multimèdia. A mesura que les xarxes mòbils han anat evolucionant cap a un paradigma “All-IP”, particularment en xarxes 4G i 5G, 3GPP va seleccionar els protocols i arquitectures destinats a gestionar la senyalització dels serveis mòbils presents i futurs. En un moment determinat 3GPP decideix que, a diferència dels sistemes 2G i 3G que fan servir protocols basats en SS7, els sistemes de nova generació farien servir protocols estandarditzats per IETF. Quan 3GPP va començar a estandarditzar el servei de Streaming sobre xarxes mòbils PSS (Packet-switched Streaming Service) va escollir el protocol RTSP com a mecanisme de senyalització. Encara més significatiu, el protocol SIP va ser escollit com a mecanisme de senyalització per a IMS (IP Multimedia Subsystem), l’arquitectura de nova generació que substituirà la xarxa telefònica tradicional i permetrà el desplegament de nous serveis multimèdia. La decisió per part de 3GPP de seleccionar protocols estàndards definits per IETF ha representat una fita cabdal per a la convergència del sistemes All-IP fixes i mòbils, i per al desenvolupament de xarxes NGN (Next Generation Networks) en general. En aquest context, el nostre objectiu inicial ha estat analitzar com aquests protocols de senyalització multimèdia, dissenyats per a xarxes IP genèriques, es comporten sobre xarxes mòbils 3GPP. Efectivament, l’ús de protocols IP és fonamental de cara a facilitar la interoperabilitat de solucions diferents. Per altra banda, hi ha escenaris a on és possible aprofitar informació de “context” addicional per a millorar el comportament d’aquests protocols en al cas particular de xarxes mòbils. El cos principal del treball de la tesi ha consistit en l’anàlisi i optimització del rendiment dels protocols de senyalització multimèdia SIP i RTSP, i la definició d’arquitectures de desplegament, amb èmfasi en els serveis 3GPP PSS i 3GPP Mission Critical Push-to-Talk (MCPTT). Aquest treball ha estat precedit per una feina d’anàlisi detallada del comportament dels protocols IP, TCP i UDP sobre xarxes 3GPP, que va proporcionar els fonaments adequats per a la posterior tasca d’anàlisi de protocols de senyalització sobre xarxes mòbils. Les contribucions inclouen la proposta de noves optimitzacions per a millorar els procediments d’establiment de sessions de streaming multimèdia, l’anàlisi detallat i optimització del servei de Presència basat en SIP i la definició de nous casos d’ús i exemples de desplegament d’arquitectures optimitzades per al servei 3GPP MCPTT. Aquestes contribucions ha quedat reflectides en un llibre, tres articles publicats en Revistes Internacionals amb índex JCR, 5 articles publicats en Conferències Internacionals, un article publicat en Congrés Nacional i l’adjudicació d’una patent. La tesi proporciona una descripció detallada de totes les contribucions, així com un exhaustiu repàs del seu context, dels principis fonamentals subjacents a totes les contribucions, la seva aplicabilitat a diferents tipus de desplegaments de xarxa (des de 2.5G a 5G), així una presentació detallada de les arquitectures associades definides per organismes com OMA o 3GPP. Finalment també es presenta l’evolució potencial de la tasca de recerca cap a sistemes 5G.Postprint (published version

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

Review of network integration techniques for mobile broadband services in next generation network

Next Generation Network (NGN) is intended at integrating the existing heterogeneous wireless access networks in order to produce a composite network that provides users with ubiquitous broadband experience. Currently, it has been established that Long Term Evolution (LTE) network, as a backbone network, provides broadband capacity with high efficiency, reduced latency and improved resource provisioning. Resource provisioning on this backbone network is not without its limitation as more mobile broadband services (MBBs) are evolving and users demand for mobility is on the increase. This paper, therefore, reviewed the different integration techniques for the heterogeneous networks that use LTE network as backbone that supports mobile broadband services.Keywords: MBB, NGN, LTE, SIP, Qo

New Waves of IoT Technologies Research – Transcending Intelligence and Senses at the Edge to Create Multi Experience Environments

The next wave of Internet of Things (IoT) and Industrial Internet of Things (IIoT) brings new technological developments that incorporate radical advances in Artificial Intelligence (AI), edge computing processing, new sensing capabilities, more security protection and autonomous functions accelerating progress towards the ability for IoT systems to self-develop, self-maintain and self-optimise. The emergence of hyper autonomous IoT applications with enhanced sensing, distributed intelligence, edge processing and connectivity, combined with human augmentation, has the potential to power the transformation and optimisation of industrial sectors and to change the innovation landscape. This chapter is reviewing the most recent advances in the next wave of the IoT by looking not only at the technology enabling the IoT but also at the platforms and smart data aspects that will bring intelligence, sustainability, dependability, autonomy, and will support human-centric solutions.acceptedVersio

Infrastructure sharing of 5G mobile core networks on an SDN/NFV platform

When looking towards the deployment of 5G network architectures, mobile network operators will continue to face many challenges. The number of customers is approaching maximum market penetration, the number of devices per customer is increasing, and the number of non-human operated devices estimated to approach towards the tens of billions, network operators have a formidable task ahead of them. The proliferation of cloud computing techniques has created a multitude of applications for network services deployments, and at the forefront is the adoption of Software-Defined Networking (SDN) and Network Functions Virtualisation (NFV). Mobile network operators (MNO) have the opportunity to leverage these technologies so that they can enable the delivery of traditional networking functionality in cloud environments. The benefit of this is reductions seen in the capital and operational expenditures of network infrastructure. When going for NFV, how a Virtualised Network Function (VNF) is designed, implemented, and placed over physical infrastructure can play a vital role on the performance metrics achieved by the network function. Not paying careful attention to this aspect could lead to the drastically reduced performance of network functions thus defeating the purpose of going for virtualisation solutions. The success of mobile network operators in the 5G arena will depend heavily on their ability to shift from their old operational models and embrace new technologies, design principles and innovation in both the business and technical aspects of the environment. The primary goal of this thesis is to design, implement and evaluate the viability of data centre and cloud network infrastructure sharing use case. More specifically, the core question addressed by this thesis is how virtualisation of network functions in a shared infrastructure environment can be achieved without adverse performance degradation. 5G should be operational with high penetration beyond the year 2020 with data traffic rates increasing exponentially and the number of connected devices expected to surpass tens of billions. Requirements for 5G mobile networks include higher flexibility, scalability, cost effectiveness and energy efficiency. Towards these goals, Software Defined Networking (SDN) and Network Functions Virtualisation have been adopted in recent proposals for future mobile networks architectures because they are considered critical technologies for 5G. A Shared Infrastructure Management Framework was designed and implemented for this purpose. This framework was further enhanced for performance optimisation of network functions and underlying physical infrastructure. The objective achieved was the identification of requirements for the design and development of an experimental testbed for future 5G mobile networks. This testbed deploys high performance virtualised network functions (VNFs) while catering for the infrastructure sharing use case of multiple network operators. The management and orchestration of the VNFs allow for automation, scalability, fault recovery, and security to be evaluated. The testbed developed is readily re-creatable and based on open-source software

VoLTE: Fundamentals and Investment under Uncertainty by analogy with the Real Options Theory – A real case application in Greek Telecommunications market

Με την εμφάνιση των Τηλεπικοινωνιών, η φωνή έσπασε όλα τα φυσικά όρια και έγινε πραγματικότητα η μετάδοσή της παγκοσμίως σε πραγματικό χρόνο. Σύντομα, οι υπηρεσίες φωνής μετατράπηκαν σε βασική δραστηριότητα για τους παρόχους και το έναυσμα για την ανάπτυξη των Σταθερών και Κινητών Τηλεπικοινωνιών. Η τελευταία λέξη της τεχνολογίας για την Κινητή μετάδοση φωνής είναι το Voice over LTE (VoLTE), το οποίο αποτελεί μια σημαντική δυνατότητα του δικτύου για τη ουσιαστική βελτίωση της απόδοσης της φωνής και της χωρητικότητας του ραδιοδικτύου με ταυτόχρονη μείωση στα λειτουργικά κόστη. Στην παρούσα διπλωματική εργασία παρουσιάζονται οι βασικές αρχές της αρχιτεκτονικής VoLTE και παρέχεται μία ανάλυση της τεχνολογίας VoLTE ως επενδυτική ευκαιρία. Στο πρώτο μέρος παρατίθεται μια ιστορική αναδρομή σχετικά με την εξέλιξη των συστημάτων φωνής των Κινητής Τηλεπικοινωνιών από την πρώτη γενιά έως σήμερα. Περιλαμβάνεται μια επισκόπηση της αρχιτεκτονικής VoLTE με ανάλυση των κύριων υποσυστημάτων και των βασικών τους στοιχείων με βάση τις τεχνικές προδιαγραφές. Επιπλέον, παρουσιάζονται οι βασικές λειτουργίες μετάδοσης φωνής μέσω της τεχνολογίας VoLTE. Στο επόμενο μέρος περιγράφονται τα οφέλη και οι προκλήσεις που γεννιούνται από την ανάπτυξη της λύσης VoLTE, από τεχνικής άποψης αλλά και από πλευράς αγοράς. Για τον μετριασμό των κινδύνων, προτείνεται από τις χρηματοπιστωτικές αγορές η θεωρία των για την αξιολόγηση της επένδυσης, με βάση τη σύγχρονη βιβλιογραφία. Η ζήτηση της υπηρεσίας VoLTE μοντελοποιείται χρησιμοποιώντας τη γεωμετρική κίνηση Brown και αναπτύσσεται μια μεθοδολογία βασισμένη στα πραγματικά δικαιώματα προαίρεσης μέσω του δυναμικού προγραμματισμού, για τον υπολογισμό των βέλτιστων επενδυτικών κανόνων και του κόστους ευκαιρίας. Στο έκτο κεφάλαιο, παρουσιάζεται ένα παράδειγμα πραγματικής περίπτωσης επένδυσης VoLTE στην ελληνική αγορά Κινητών Τηλεπικοινωνιών, χρησιμοποιώντας την προτεινόμενη μεθοδολογία των πραγματικών δικαιωμάτων προαίρεσης. Τα αποτελέσματα συγκρίνονται με την παραδοσιακή προσέγγιση και αναλύονται με την χρήση προσομοιώσεων Monte Carlo. Συμπεράσματα και ενδιαφέροντα ευρήματα παρέχονται στο τελευταίο κεφάλαιο.With the emergence of Telecommunications, the voice broke all physical borders and could be transferred worldwide in real-time. Soon, voice services became a core business for the providers and the trigger for the development of Fixed and Mobile Telecommunications. The state of the art for mobile voice delivery is Voice over LTE (VoLTE), which is an important network capability to significantly improve the service performance and radio capacity while reducing operating costs. This study thesis presents the fundamental principles of VoLTE architecture and provides an analysis of the VoLTE solution as an investment opportunity. In the first part, a historical review is given regarding the evolution of the Cellular Mobile Telecommunication systems since their first generation. An overview of the VoLTE architecture is included with an analysis of the main subsystems and the core components based on the technical specifications. Moreover, the basic functionalities of the VoLTE technology are presented. The next part describes the benefits and challenges of deploying the VoLTE solution from technical and market perspectives. In order to mitigate the risks, the Real Options theory from the financial market is introduced for evaluating the VoLTE investment according to modern literature. The VoLTE demand is modelled using the Geometric Brownian Motion process and the dynamic programming is used to structure a Real Options-based framework for calculating optimal investment rules and opportunity cost. In the sixth chapter, a real case application of the proposed framework in the Greek Mobile Telecommunications market is presented. The results are compared with the traditional tools and analyzed by performing Monte Carlo simulations. Conclusions and interesting insights are provided in the last chapter

Comunicaciones Móviles de Misión Crítica sobre Redes LTE

Mission Critical Communications (MCC) have been typically provided by proprietary radio technologies, but, in the last years, the interest to use commercial-off-the-shelf mobile technologies has increased. In this thesis, we explore the use of LTE to support MCC. We analyse the feasibility of LTE networks employing an experimental platform, PerformNetworks. To do so, we extend the testbed to increase the number of possible scenarios and the tooling available. After exploring the Key Performance Indicators (KPIs) of LTE, we propose different architectures to support the performance and functional requirements demanded by MCC. We have identified latency as one of the KPI to improve, so we have done several proposals to reduce it. These proposals follow the Mobile Edge Computing (MEC) paradigm, locating the services in what we called the fog, close to the base station to avoid the backhaul and transport networks. Our first proposal is the Fog Gateway, which is a MEC solution fully compatible with standard LTE networks that analyses the traffic coming from the base station to decide whether it has to be routed to the fog of processed normally by the SGW. Our second proposal is its natural evolution, the GTP Gateway that requires modifications on the base station. With this proposal, the base station will only transport over GTP the traffic not going to the fog. Both proposals have been validated by providing emulated scenarios, and, in the case of the Fog Gateway, also with the implementation of different prototypes, proving its compatibility with standard LTE network and its performance. The gateways can reduce drastically the end-to-end latency, as they avoid the time consumed by the backhaul and transport networks, with a very low trade-off