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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Availability-Aware Spare Capacity Allocation with Partially Protected Rings

Zulhasnine, Mohammad January 2008 (has links)
This thesis work focuses on designing a survivable IP-core network with the minimal investment of spare capacity. A span-oriented spare capacity allocation (SCA) scheme is proposed to satisfy customers' availability requirements in the end-to-end (E2E) sense. The novelty of the proposed SCA scheme is that it meets the E2E availability requirements despite the lack of knowledge of E2E bandwidth by employing protection rings covering all links in the network. Different ring selection methods are presented and also compared from the aspect of network redundancy and LP feasibility which provide more flexibility to the design. The proposed SCA algorithm further minimizes total cost of spare capacity by incorporating partial protection within the proposed architecture. The simulation results show that it can significantly reduce the spare capacity consumption depending on the availability. The proposed SCA scheme also performs better in terms of redundancy than that of two other dominant methods available these days.
2

Availability-Aware Spare Capacity Allocation with Partially Protected Rings

Zulhasnine, Mohammad January 2008 (has links)
This thesis work focuses on designing a survivable IP-core network with the minimal investment of spare capacity. A span-oriented spare capacity allocation (SCA) scheme is proposed to satisfy customers' availability requirements in the end-to-end (E2E) sense. The novelty of the proposed SCA scheme is that it meets the E2E availability requirements despite the lack of knowledge of E2E bandwidth by employing protection rings covering all links in the network. Different ring selection methods are presented and also compared from the aspect of network redundancy and LP feasibility which provide more flexibility to the design. The proposed SCA algorithm further minimizes total cost of spare capacity by incorporating partial protection within the proposed architecture. The simulation results show that it can significantly reduce the spare capacity consumption depending on the availability. The proposed SCA scheme also performs better in terms of redundancy than that of two other dominant methods available these days.
3

Realization of Differentiated Quality of Service for Wideband Code Division Multiple Access Core Network

Fang, Yechang 05 March 2010 (has links)
The development of 3G (the 3rd generation telecommunication) value-added services brings higher requirements of Quality of Service (QoS). Wideband Code Division Multiple Access (WCDMA) is one of three 3G standards, and enhancement of QoS for WCDMA Core Network (CN) becomes more and more important for users and carriers. The dissertation focuses on enhancement of QoS for WCDMA CN. The purpose is to realize the DiffServ (Differentiated Services) model of QoS for WCDMA CN. Based on the parallelism characteristic of Network Processors (NPs), the NP programming model is classified as Pool of Threads (POTs) and Hyper Task Chaining (HTC). In this study, an integrated programming model that combines both of the two models was designed. This model has highly efficient and flexible features, and also solves the problems of sharing conflicts and packet ordering. We used this model as the programming model to realize DiffServ QoS for WCDMA CN. The realization mechanism of the DiffServ model mainly consists of buffer management, packet scheduling and packet classification algorithms based on NPs. First, we proposed an adaptive buffer management algorithm called Packet Adaptive Fair Dropping (PAFD), which takes into consideration of both fairness and throughput, and has smooth service curves. Then, an improved packet scheduling algorithm called Priority-based Weighted Fair Queuing (PWFQ) was introduced to ensure the fairness of packet scheduling and reduce queue time of data packets. At the same time, the delay and jitter are also maintained in a small range. Thirdly, a multi-dimensional packet classification algorithm called Classification Based on Network Processors (CBNPs) was designed. It effectively reduces the memory access and storage space, and provides less time and space complexity. Lastly, an integrated hardware and software system of the DiffServ model of QoS for WCDMA CN was proposed. It was implemented on the NP IXP2400. According to the corresponding experiment results, the proposed system significantly enhanced QoS for WCDMA CN. It extensively improves consistent response time, display distortion and sound image synchronization, and thus increases network efficiency and saves network resource.
4

Software defined virtualized cloud radio access network (SD-vCRAN) and programmable EPC for 5G

Banik, Pushpanjali January 2018 (has links)
This thesis focuses on proposing a Software Defined Network (SDN) based programmable and capacity optimized backhaul and core network which is critical for 5G network design. Cloud Radio Access networks (CRAN) which is key enabler of 5G networks can address a number of challenges that mobile operators face while trying to support ever-growing end-users' needs towards 5th generation of mobile networks (5G). A novel layered and modular programmable CRAN architecture called Software Defined Virtualised Cloud Radio Access Network (SD-vCRAN) is introduced with Network Function Virtualization (NFV) and Software Defined Network (SDN) capabilities. The SDN-Base Band Unit (BBU) pool is shifted to the programmable core network site, where a centralised SDN controller manages the network servers and virtualised network function entities - Mobile Management Entity (MME), Serving/Packet Data Network Data plane (S/PGW-D), Serving/Packet Data Network Control plane (S/PGW-C), Software Network Defined Baseband Unit (SDN-BBU) and Local controllers (LC) via OpenFlow (OF) protocol. This approach simplifies network operations, improve traffic management, enable system-wide optimisation of Quality of Service (QoS) and network-aware application development. The control plane (excluding the preserved 3GPP standard interfaces: S1-MME, S6a, Gx) managed by the network servers provides load balancing, traffic management and optimisation tools for the data plane. The proposed work starts by reviewing the requirements of 5G networks, followed by discussion on 5G backhaul and core challenge. Then, an overview of CRAN, Evolved Programmable Core (EPC), SDN, NFV and related works. The simulation details of the proposed architecture are discussed along with the challenges faced by adopting SDN and NFV in mobile core. A thorough assessment of the interfaces and protocols that should be conserved or enhanced on both data and control plane is conducted. The result enables an architecture where the SDN-BBU pool shares a single cloud with the programmable EPC and the control plane is migrated from the network elements to a centralized controller, running on a virtual machine in the mobile core. The data and control plane separation removes overlaps and provides better signalling, as well as efficient network functioning to comply with latency demands. The proposed system performance is validated in terms of throughput, datagram loss, and packet delay variation under three scenarios: 1. single policy installation, 2. multiple policy installation and 3. load balancing. The load balancing performance of proposed system is validated comparing the performance of two different SDN controllers: Floodlight and OpenDaylight, where the later performs better in terms of throughput (no bandwidth restriction), packet loss (below 0.3%) and jitter (below 0.2ms). Furthermore, a detailed comparison of two SDN controller's - Floodlight and OpenDaylight performances is presented, which shows that OpenDaylight performs better only for less dense networks which needs less processing of messages without being blocked, and the Floodlight performs better in ultra-dense network. Some directions and preliminary thoughts for future work and necessary information to operators for building their roadmap to the upcoming technologies is presented.
5

Μελέτη μελλοντικού 4G UMTS δικτύου με IP διασύνδεση στο Core Network

Κακαβέτσος, Βλάσιος 26 June 2008 (has links)
Στην εργασία αυτή μελετήθηκε το μελλοντικό δίκυο 4G UMTS με ΙΡ διασύνδεση στο δίκτυο πυρήνα. Επίσης μελετώ τα νέα πρωτόκολλα για mobile internet IPV4, IPV6 καθώς επίσης και την πολυμεσική δομή ΙΜS. / In this Maste thesis, study the 4G UMTS network with IP conection in the core network. So i analyze the new protocolls for mobile internet IPV4, IPV6 and the multimedia structure IMS
6

Efficient traffic monitoring in 5G Core Network

Girondi, Massimo January 2020 (has links)
5G is an enabler to several new use cases. To support all of them, the network infrastructure must be flexible and it should adapt to the different situations. This feature is powered by SDN, NFV, and Automation, three of the main pillars on which the 5G network is built.Traditional network management approaches may not be suitable for the 5G Core Network User Plane, which holds strict requirements in terms of latency and throughput. Therefore, Artificial Intelligence agents have been proposed to manage the 5G in a more efficient manner, delivering a more optimized allocation of the resources. This approach requires real-time monitoring of the data passing by the Core Network, a feature not standardized by the current protocols. In this thesis, the design of a monitoring protocol for the 5G Core Network User Plane has been studied, focusing on precise measurement of latencies. Then, a In-band Network Telemetry (INT) framework has been implemented on top of a User Plane Function prototype. The prototype is built on top of a novel User Plane implementation, based on chaining of atomic functions called micro-UPFs (µUPFs).While the main focus of this work has been latency measurement, packet counters, byte counters and Inter Packet Gap values can be collected from the framework, proving the main KPIs of a 5G User Plane. The INT framework has been implemented through two new µUPFs, one for updating the INT metadata and one for collecting them. These metadata are attached to the user packets as GTP-U extended header, maintaining compatibility with the standard protocol. Moreover, the implemented framework allows high flexibility through dynamic tuning of the parameters, providing mechanisms to reduce the amount of telemetry data generated and, thus, the system overhead.The framework has been tested on a physical setup of four server machines, abstracting a Core Network User Plane, connected with 10 Gbps NICs. In all the tests performed, the performances of the User Plane are affected by the new functionalities only when INT metadata are inserted very frequently. The results show that is possible to monitor the three main KPIs of a 5G User Plane without heavily limiting the system performances. / 5G är en möjliggörare för flera nya användningsfall: för att stödja dem alla måste nätverksinfrastrukturen vara flexibel och den ska anpassa sig till de olika situationerna. Denna funktion drivs av SDN, NFV och Automation, tre av de viktigaste pelarna som 5G-nätverket är byggt på.Traditionella nätverkshanteringsstrategier kanske inte passar för 5G Core Network, som har strikta krav när det gäller latens och genomströmning. Därför har Artificial Intelligence-agenter föreslagits att hantera 5G på ett mer effektivt sätt, vilket ger en mer optimerad fördelning av resurserna. Detta tillvägagångssätt kräver realtidsövervakning av data som passerar via Core Network, en funktion som inte standardiseras med de aktuella protokollen.I denna avhandling har utformningen av ett övervakningsprotokoll för 5G Core Network User Plane studerats med fokus på exakt mätning av latenser. Sedan har ett in-band Network Telemetry (INT) -ramverk implementerats ovanpå en prototyp för User Plane Function. Denna prototyp utnyttjade Chain Controllerarkitekturen, en ny användarplan-implementering baserad på kedjan av atomfunktioner som kallas µUPF.Medan huvudfokuset för detta arbete har varit latensmätning, kan paketräknare, byttäknare och Inter Packet Gap-värden samlas in från ramverket, vilket bevisar de viktigaste KPI: erna i ett 5G-nätverk. INT-ramverket har implementerats genom två nya µUPF, en för att uppdatera INT-metadata och en för att samla dem. Dessa metadata är anslutna till användarpaketen som GTP-U utökad rubrik, bibehållande kompatibilitet med standardprotokollet. Dessutom tillåter det implementerade ramverket hög flexibilitet som tillåter dynamisk inställning av parametrarna, tillhandahåller mekanismer för att minska mängden telemetri-data som genereras och därmed systemomkostnaderna.Ramverket har testats på en fysisk installation av fyra servermaskiner som abstraherar ett Core Network User Plane, anslutet med 10 Gbps NIC. I samtliga tester påverkas testbäddens prestationer av de nya funktionerna först när INT-metadata sätts in mycket ofta. Resultaten visar att det är möjligt att övervaka de tre huvudsakliga KPI: erna i ett 5G-nätverk utan att starkt begränsa systemprestanda.
7

The Environmental Impacts of Core Networks for Mobile Telecommunications. : A Study Based on the Life Cycle Assessment (LCA) of Core Network Equipment.

Pino, Albena January 2017 (has links)
No description available.
8

Leksandsbrons deformationsövervakning med geodetiska metoder

Olhans, Linnéa January 2018 (has links)
Av olika orsaker sker rörelser i strukturer, vilket leder till att deformationer uppstår. För att upptäcka deformationer krävs att förändringarna övervakas regelbundet. Övervakning kan ske på olika sätt. När detta utförs bör ett stomnät, upprättat av referenspunkter av god kvalitet, finnas tillgängligt. Stomnätet ger en grund för deformationsmätningen och gör att instrumentet som används, kan erhålla en lokalisering av var referenspunkterna placeras innan mätningen av strukturen utförs. 2014 utförde konsultföretaget Sweco, med uppdrag från Leksands kommun, en deformationsmätning av Leksandsbron, som är en gammal bågvalvsbro från 1925 i Leksands kommun, Dalarnas län. Syftet var att undersöka brons hållbarhet, men några slutsatser kunde inte dras utifrån den mätningen. I denna studie är syftet att ge förslag på hur Swecos stomnät skulle kunna utvecklas. Kompletteringen av stomnätet utfördes genom en simulering i programvaran SBG Geo där ett antal av Swecos kända stompunkter valdes och nya stompunkter placerades ut grafiskt med avseende på kvalitet, tillförlitlighet, geometri och ekonomiska aspekter i tre scenarier. Ett stomnät kan se ut på många olika sätt i teorin, men i praktiken är omgivningen begränsad vid bromätningar. Nätutjämning av förslagen fick senare klargöra vilket nät som var det bästa för att använda som referens till inmätningen av bron. Kompletteringen resulterade i att det förslag som var det mest lämpade också var det som var bäst anpassat till brons omgivning, natur och sikt. Det bästa förslaget har därefter användes därefter till inmätning av Leksandsbron, där Swecos deformationsmätning utgjorde referens. Inmätningen av stomnätet och bron utfördes med totalstationen Trimble S7. Genom nätutjämning beräknades nätets koordinater och osäkerheter från observationerna och differenserna jämfördes mot Swecos punkter för att se om någon deformation uppstått. Resultatet visar att två av Swecos punkter och några av brons punkter har utsatts för deformation. Deformationen för punkternas avvikelser analyserades också genom att använda t-student signifikanstest på ett konfidensintervall av 95%. Är avvikelsen inom intervallet har punkten inte rört sig och är avvikelsen utanför konfidensintervallet har punkten rört sig. Signifikanstestet visade att de punkter som utsatts för deformation i nätutjämningen även är signifikanta i t-student testet och bekräftade att punkterna har rört sig. / For different reasons there are movements in structures, which leads to deformations. To monitor deformations, the changes have to be monitored on a regular basis. Monitoring can take place in different ways. When doing this, a core network based on good quality reference points, should be available. The core network provides a basis for deformation measurements and allows the instrument to predict a suitable location before measuring of the structure. In 2014, the consultancy company Sweco, commissioned by Leksands municipality, made deformation measurements of Leksandsbron, an old arch bridge from 1925, situated in Leksand, Dalecarlia. The intention was to investigate the sustainability of the bridge, but it was not possible to draw any conclusions from the measurements from 2014. The purpose of this study is to give suggestions on how the core network from Sweco could be developed. The completion was performed by a simulation in SBG Geo Software where some known points from Sweco were chosen as a reference and new points were graphically placed in terms of quality, reliability, geometry and economic aspects in three scenarios. A core network can look in many different ways theoretically, but practically, and especially at bridge measurements, there are limitations. By network adjustment of the proposals it could be clarified, which network was the best one to use for the survey of the bridge. The result of the completion was that the best suited proposal also was the one best suited to the surroundings, nature and visibility of the bridge The best suggestion was used for the bridge measurement with Sweco´s deformation measurement as a reference. The survey of the core network and the points of the bridge was performed by the Trimble S7 total station. With network adjustment the coordinates and assurances were calculated and the differences were compared to Sweco points to see if any deformation had occurred. The result showed that two of Sweco´s points and some of the bridge points have been exposed to deformation. The deformation has also been analyzed for the deviations of the core network points and the bridge points by using t-student significance test of a confidence interval of 95%. If the deviation is within the range it´s considered that the point has not moved and if the deviation is outside the range it´s considered that the point has moved. The significance test showed that the same points that had been exposed to deformation in the network adjustment, also were significant in the t-student test, which confirms that the points have moved.
9

Emulation of IP Core Network for Testing of the Serving GRPS Support Node (SGSN) Routing Application

Torkaman, Hossein January 2009 (has links)
<p>This thesis aims to investigate a method and tool for emulation of the General Packet Radio Service (GPRS) core network needed as an environment to test the routing functionality. GPRS is the most widely adopted mobile packet data delivery technology in the world. It utilizes an Intranet Protocol (IP)-based core network and involves significant changes to the way the Global System for Mobile communications (GSM) air interface is structured. It also forms the basis of the future structure of mobile network transmission and switching.</p><p>The Serving GPRS Support Node (SGSN) is the most fundamental node in GPRS. Ericsson produces and manages an increasing number of SGSN nodes in the world. One of main functionalities of SGSN node is to forward IP packets according to the destination address in the IP header on IP core network.</p><p>In each new release of SGSN, or when implementation or upgrades have been done on routing application on SGSN, design and test engineers at Ericsson need to emulate the IP core network. This must be done with use of many routers to generate huge amounts of data that can simulate the real world IP core network.</p><p>The major goal of this thesis was to analyze and verifying the use of a suitable and economical solution to emulating IP Core Network of the GPRS system for testing of different functionality of the routing application running in SGSN , instead of building up a physical Core Network with different infrastructure and many routers.</p><p>The method chosen for emulating the IP core network with many routers, and investigated in the thesis, is based on a Cisco simulator called “Dynamips”, which runs many actual Cisco Internetwork Operating Systems (IOS) with many different models of Cisco products in a virtual environment on Windows or Linux platforms. With this simulator, engineers at Ericsson will be able to use this simulator to emulate IP core network easily and efficiently to accomplish system test cases.</p><p>A conclusion of this work is that Dynamips could be used to emulate many complicated IP core network scenarios, with many routers to generate huge amounts of data to simulate the real world IP core network. The emulated system fulfils its purpose for testing of the routing application of SGSN regarding different functionality and characteristics. This is done to ensure and verify that SGSN routing application meets its functional and technical requirements, and also helps to find undiscovered errors as well as helps to ensure that the individual components of routing application on SGSN are working correctly.</p>
10

Transformation av stomnät till SWEREF 99 : Fallstudie Norra Vätö, Norrtälje kommun / Transformation of the Core Network to SWEREF 99 : Case Study of North Vätö, Norrtälje municipality

Ingelman-Sundberg, Simon, Mishal Salem, Ali January 2010 (has links)
Sverige har under lång tid haft flera olika koordinatsystem, både nationella och lokala. Nu genomförs en övergång till ett gemensamt koordinatsystem som kallas SWEREF 99. I Norrtälje kommun finns stomnät som är noterade i ett flertal olika koordinatsystem, med ursprung i tidigare förrättningar. Åtskilliga av dessa har dålig orientering i kända nationella koordinatsystem men däremot god inre noggrannhet. I detta arbete väljs 12 stomnät för transformation till SWEREF 99 18 00. Detta görs genom att passpunkter mäts in med GNSS-teknik. De inmätta punkterna används sedan för att transformera stomnäten som de är noterade i. Detta gör att i framtiden kan till exempel husutsättningar i de aktuella områdena utföras med enbart GNSS-teknik. Stomnäten som väljs finns på norra delen av ön Vätö i Norrtälje kommun. GNSS-utrustningen som används för att mäta in punkterna är Leica 1203 nätverks-RTK. De valda passpunkterna mäts in vid två tillfällen med minst 45 minuters mellanrum. Vid varje tillfälle görs 10 mätningar. Sedan beräknas medelvärdet av 20 mätningar. När alla punkter väl har mätts in görs transformationer från tre olika från-system till SWEREF 99 18 00. De tre från-systemen är RT 38 2,5 gon V, RT R09 0 gon och ett lokalt 1000/1000-system. Eftersom områdena som är noterade i RT 38 är dåligt orienterade gentemot varandra ger det dålig noggrannhet att transformera hela RT 38-området på en gång. Därför delas RT 38-området in i flera transformationsområden. När transformationen gjorts kontrollmäts fastighetsgränser i ett gränsområde där gränspunkternas koordinatsystem är osäkert. Avslutningsvis kontrollmäts en Rix 95-punkt med namnet Klockarängsberget (Rix 95-punktnummer: 119741) som finns på södra delen av Vätö. / During the last century different coordination systems have been used in Sweden. Today a common coordination system (SWEREF 99) is used. In the municipality of Norrtälje, core networks are listed in different coordination systems that are generated from different earlier missions. These networks normally have poor orientation in the known coordination system; however, the internal accuracy is used to be good. In this study, some of the core networks have been selected to be converted to SWEREF 99 18 00. The conversion has been done by measuring points using the GNSS technology, the measured points were then used to transfer the core network to SWEREF 99 18 00. This means that in the future, staking out a building in the area can be performed solely by GNSS technology. The chosen core networks are located on a part of the island Vätö in the municipality of Norrtälje. The GNSS equipment used to measure the points with was the Leica 1203 RTK network. The selected points were measured on two occasions with a gap between the occasions of at least 45 minutes. Ten repeated measurements have been done on each point to increase the accuracy. The average of these twenty measurements has been used for conversion. After the measuring process, the transformation has been done from three different off-systems to SWEREF 99 18 00. The three off-systems were RT 38 2.5 gon V, RT R09 0 gon and a local 1000/1000-system. Since the areas listed in the RT 38 were poorly oriented towards each others, poor accuracy was achieved during the transformation of the entire RT 38 field at once. Therefore, the RT 38 area has been divided into a number of transformations-areas. When the transformation had been done, control measurements were made on a Rix 95-Point entitled Klockarängsberget (Rix 95-point numbers: 119 741) located on the southern part of Vätö. In addition, control measurements were made of housing estate border area, where the border points were uncertain.

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