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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

3GPP Long Term Evolution LTE Scheduling

Alotaibi, Sultan 12 1900 (has links)
Future generation cellular networks are expected to deliver an omnipresent broadband access network for an endlessly increasing number of subscribers. Long term Evolution (LTE) represents a significant milestone towards wireless networks known as 4G cellular networks. A key feature of LTE is the implementation of enhanced Radio Resource Management (RRM) mechanism to improve the system performance. The structure of LTE networks was simplified by diminishing the number of the nodes of the core network. Also, the design of the radio protocol architecture is quite unique. In order to achieve high data rate in LTE, 3rd Generation Partnership Project (3GPP) has selected Orthogonal Frequency Division Multiplexing (OFDM) as an appropriate scheme in terms of downlinks. However, the proper scheme for an uplink is the Single-Carrier Frequency Domain Multiple Access due to the peak-to-average-power-ratio (PAPR) constraint. LTE packet scheduling plays a primary role as part of RRM to improve the system’s data rate as well as supporting various QoS requirements of mobile services. The major function of the LTE packet scheduler is to assign Physical Resource Blocks (PRBs) to mobile User Equipment (UE). In our work, we formed a proposed packet scheduler algorithm. The proposed scheduler algorithm acts based on the number of UEs attached to the eNodeB. To evaluate the proposed scheduler algorithm, we assumed two different scenarios based on a number of UEs. When the number of UE is lower than the number of PRBs, the UEs with highest Channel Quality Indicator (CQI) will be assigned PRBs. Otherwise, the scheduler will assign PRBs based on a given proportional fairness metric. The eNodeB’s throughput is increased when the proposed algorithm was implemented.
2

Strategic Location Planning for Broadband Access Networks under Cooperative Transmission

Lin, Bin 23 April 2009 (has links)
To achieve a cost-effective network deployment, employing state-of-art technical advances provides a practical and effective way to enhance system performance and quality of service provisioning. Cooperative transmission has been recognized as one of the most effective paradigms to achieve higher system performance in terms of lower bit-error rate, higher throughput, larger coverage, more efficient energy utilization, and higher network reliability. This dissertation studies the location planning for the deployment of broadband access networks and explores the great potential of cooperative transmission in the context of single-cell cooperative relaying and multi-cell cooperative transmission, respectively. The placement problem is investigated in two categories of network deployment environment, i.e., an existing wireless access network and a perspective broadband access network, respectively. In an existing wireless access network, to solve some practical problems such as the requirements of capacity enhancement and coverage extension, relay stations (RSs) are introduced in the network architecture. We propose two optimization frameworks with the design objectives of maximizing cell capacity and minimizing number of RSs for deployment, respectively. Mathematical formulations are provided to precisely capture the characteristics of the placement problems. The corresponding solution algorithms are developed to obtain the optimal (or near-optimal) results in polynomial time. Numerical analysis and case studies are conducted to validate the performance benefits due to RS placement and the computation efficiency of the proposed algorithms. To deploy a new metropolitan-area broadband access network, we explore the integration of passive optical network (PON) and wireless cooperative networks (WCN) under the multi-cell cooperative transmission technology. An optimization framework is provided to solve the problem of dimensioning and site planning. The issues of node placement, BS-user association, wireless bandwidth and power breakdown assignment are jointly considered in a single stage to achieve better performance. We also propose a solution to the complex optimization problem based on decomposition and linear approximation. Numerical analysis and case studies are conducted to verify the proposed framework. The results demonstrate the performance gains and economic benefits. Given a set of network parameters, the proposed optimization frameworks and solutions proposed in this dissertation can provide design guidelines for practical network deployment and cost estimations. And the constructed broadband access networks show a more cost-effective deployment by taking advantage of the cooperative transmission technology.
3

Strategic Location Planning for Broadband Access Networks under Cooperative Transmission

Lin, Bin 23 April 2009 (has links)
To achieve a cost-effective network deployment, employing state-of-art technical advances provides a practical and effective way to enhance system performance and quality of service provisioning. Cooperative transmission has been recognized as one of the most effective paradigms to achieve higher system performance in terms of lower bit-error rate, higher throughput, larger coverage, more efficient energy utilization, and higher network reliability. This dissertation studies the location planning for the deployment of broadband access networks and explores the great potential of cooperative transmission in the context of single-cell cooperative relaying and multi-cell cooperative transmission, respectively. The placement problem is investigated in two categories of network deployment environment, i.e., an existing wireless access network and a perspective broadband access network, respectively. In an existing wireless access network, to solve some practical problems such as the requirements of capacity enhancement and coverage extension, relay stations (RSs) are introduced in the network architecture. We propose two optimization frameworks with the design objectives of maximizing cell capacity and minimizing number of RSs for deployment, respectively. Mathematical formulations are provided to precisely capture the characteristics of the placement problems. The corresponding solution algorithms are developed to obtain the optimal (or near-optimal) results in polynomial time. Numerical analysis and case studies are conducted to validate the performance benefits due to RS placement and the computation efficiency of the proposed algorithms. To deploy a new metropolitan-area broadband access network, we explore the integration of passive optical network (PON) and wireless cooperative networks (WCN) under the multi-cell cooperative transmission technology. An optimization framework is provided to solve the problem of dimensioning and site planning. The issues of node placement, BS-user association, wireless bandwidth and power breakdown assignment are jointly considered in a single stage to achieve better performance. We also propose a solution to the complex optimization problem based on decomposition and linear approximation. Numerical analysis and case studies are conducted to verify the proposed framework. The results demonstrate the performance gains and economic benefits. Given a set of network parameters, the proposed optimization frameworks and solutions proposed in this dissertation can provide design guidelines for practical network deployment and cost estimations. And the constructed broadband access networks show a more cost-effective deployment by taking advantage of the cooperative transmission technology.
4

Design and Analysis of Green Mission-Critical Fiber-Wireless Broadband Access Networks

Dhaini, Ahmad R. 09 September 2011 (has links)
In recent years, the ever-increasing environmental friendliness concern has made energy efficiency in telecom networks as an important theme in their operations. Meanwhile, mission-critical (MC) services and systems (such as healthcare, police, and firefighting) have been acquiring special attention from telecom designers and operators. The currently deployed MC network technologies are indigent in terms of bandwidth capacity, and thus they are not able to support the emerging MC multimedia applications. Therefore in this thesis, we first explore the possibility of provisioning the MC services over the integration of fiber-wireless (FiWi) technologies, which has been considered as a promising candidate for the deployment of high-speed and mobile broadband access networks. We then investigate the energy efficiency problem in the FiWi integration, which consists of WiMAX in the wireless plane, and of Ethernet Passive Optical Network (EPON) - the most popular variant of the next-generation PON (NG-PON) technology, in the optical plane. In WiMAX, the energy saving protocol has been extensively investigated and standardized. Conversely, it has been recently studied in NG-PON, which currently consumes the least power among all the high-speed access networks. However, NG-PON has notably matured in the past few years and is envisioned to massively evolve in the near future. This trend will increase the power requirements of NG-PON and make it no longer coveted. Therefore we address the energy efficiency problem in NG-PON. For each of our contributions, we conduct extensive simulations to demonstrate the effectiveness and advantages of the proposed solutions.
5

Bi-directional Dense Wavelength Division Multiplexed Systems for Broadband Access Networks

Akanbi, Oladeji Bamidele 20 November 2006 (has links)
Dense wavelength division multiplexing (DWDM) is becoming the technology of choice for meeting the increasing bandwidth demands in optical networks. DWDM has been used to increase the capacity of long-haul optical transport systems. Efforts are being made to move DWDM into the broadband access network serving residential and business subscribers. First, a new centralized DWDM PON scheme is demonstrated for bi-directional upstream and downstream transmissions. The proposed DWDM PON scheme is implemented using optical carrier suppression and separation (OCSS) technology to generate a wavelength pair from a single laser source at the central office. This method enables the co-location of both upstream and downstream DWDM transmitters in the central office. In addition, the complexity, cost, and maintenance of the optical network unit are reduced by enabling wavelength independent operation. Second, a new multistage architecture is proposed for the delivery of information to groups of subscribers located at different distances from the central office. A 25 GHz DWDM comb is generated using OCSS technology, and error-free transmission of four 10 Gbps channels is demonstrated. Finally, a new wide area access network with bi-directional DWDM amplification using semiconductor optical amplifiers (SOAs) is demonstrated. The detrimental effect of SOA crosstalk resulting from cross gain modulation can be suppressed using a constant intensity modulation format such as differential phase shift keying (DPSK). The feasibiity of bi-directional DPSK transmission of 16 interleaved DWDM channels using an in-line SOA has been studied experimentally. In addition, the reduction of bi-directional SOA reflections has been realized by optimizing the SOA bias current and facet reflectivities.
6

Community Wireless Networks : a case study of Austin, Texas

Rock, Kathy 05 December 2013 (has links)
Community Wireless Networks (CWNs) are a fairly new phenomenon. One of the first projects, NYC Wireless, started in 2001. These wireless initiatives are often a response to the lack of high-speed ubiquitous computing. Many of the first users, frustrated neighborhood “techies,” jerry rigged low cost WiFi antennas to rooftops and the side of buildings in order to access a high-speed broadband service. By doing this the wireless pioneers shared high speed wireless signals with neighbors and anyone within reach of their signal. As wireless computing became more popular, and it’s social and economic benefits more obvious, CWNs became an attractive alternative for many rural and low-income urban communities. Populations that had been overlooked by large cable and telephone service companies. The success of CWNs has paved the way for municipalities to build publicly supported wireless projects. Cable and telephone companies, major providers of broadband service, view municipal networks as unfair competition, and thus began the legislative battle over municipal wireless networks. The battle continues to wage. Cable and telephone companies have had some success at the state level and the federal debate is underway at this moment. Therefore, the purpose of this report is to understand the role Austin’s nonprofits play to ensure that high speed broadband access is made available for everyone and how lessons learned in Austin can be applied to other cities and locations around the country. The study found that Austin, compared to other cities of the same size, has a very small nonprofit community to addresses the issue of universal broadband access. Although the group is small, networking and mingling between community service organizations, the city government and wireless projects has created a community that effectively addresses the issue of high-speed access to the Internet. / text
7

Design and Analysis of Green Mission-Critical Fiber-Wireless Broadband Access Networks

Dhaini, Ahmad R. 09 September 2011 (has links)
In recent years, the ever-increasing environmental friendliness concern has made energy efficiency in telecom networks as an important theme in their operations. Meanwhile, mission-critical (MC) services and systems (such as healthcare, police, and firefighting) have been acquiring special attention from telecom designers and operators. The currently deployed MC network technologies are indigent in terms of bandwidth capacity, and thus they are not able to support the emerging MC multimedia applications. Therefore in this thesis, we first explore the possibility of provisioning the MC services over the integration of fiber-wireless (FiWi) technologies, which has been considered as a promising candidate for the deployment of high-speed and mobile broadband access networks. We then investigate the energy efficiency problem in the FiWi integration, which consists of WiMAX in the wireless plane, and of Ethernet Passive Optical Network (EPON) - the most popular variant of the next-generation PON (NG-PON) technology, in the optical plane. In WiMAX, the energy saving protocol has been extensively investigated and standardized. Conversely, it has been recently studied in NG-PON, which currently consumes the least power among all the high-speed access networks. However, NG-PON has notably matured in the past few years and is envisioned to massively evolve in the near future. This trend will increase the power requirements of NG-PON and make it no longer coveted. Therefore we address the energy efficiency problem in NG-PON. For each of our contributions, we conduct extensive simulations to demonstrate the effectiveness and advantages of the proposed solutions.
8

Peer to peer networking in Ethernet broadband access networks

Damola, Ayodele January 2005 (has links)
The use of peer-to-peer (P2P) applications is growing dramatically, particularly for sharing content such as video, audio, and software. The traffic generated by these applications represents a large proportion of Internet traffic. For the broadband access network providers P2P traffic presents several problems. This thesis identifies the performance and business issues that P2P traffic has on broadband access networks employing the McCircuit separation technique. A mechanism for managing P2P within the access network is proposed. The P2P diversion algorithm aims to manage P2P traffic within the access network based on layer 2 and layer 3 information without employing intrusive layer 7 traffic detection. To solve the contention problem experienced by best effort traffic in the access network, a solution based on the diversion algorithm and on a QoS based traffic classification scheme is proposed. A business model defining the business roles and pricing schemes is presented based on the features offered by the P2P diversion algorithm introducing new opportunities for gaining revenue from P2P traffic for the network service providers and providing better services to users. / Användningen av peer-to-peer (P2P) applikationer ökar dramatiskt, speciellt för spridningen av video, musik, och mjukvara. Trafiken som skapas av dessa program utgör en stor del of trafiken på Internet. För bredbandsaccess operatörer ställer P2P trafik många problem. I detta examensarbete så identifieras både de egenskaper och affärsaspekter som P2P trafiken har på ett bredbandsaccessnät som använder McCircuit som seprationsmekanism för trafiken mellan användare och en mekanism, "peer-to-peer diversion mechansim" (P2PDA), för att hantera P2P trafiken i ett McCircuit baserat accessnät beskrivs. P2PDA algoritmen hanterar P2P trafik i accessnätet baserat på lager 2 och lager 3 information utan att ta hänsyn till applikationslagret (Lager 7). För att få en bra fördelning mellan best-effort trafik och prioriterad trafik så föreslås en lösning baserad på kombinationen av P2PDA och QoS baserad trafik klassificering. Slutligen så defineras en affärsmodell där affärsroller och olika varianter på prissättning för P2P diskuteras baserad på de egenskaper som den förslagna algoritmen medför och den ekonomiska vinst som denna lösning medger.
9

Competitive location modeling in a broadband access market: an integrated approach using GIS and spatial optimization

Lee, Gunhak 11 September 2008 (has links)
No description available.
10

Network Characterization using Active Measurements for Small Cell Networks

Saffarzadeh, Mozhgan January 2013 (has links)
Due to the rapid growth of mobile networks, network operators need to expand their coverage and capacity. Addressing these two needs is challenging. One factor is the requirement for cost-efficient transport via heterogeneous networks. In order to achieve this goal, Internet connectivity is considered a cost-efficient transport option by many operators for small cell backhaul. This thesis project investigates if a small cell network's requirements can be fulfilled by utilizing Internet connectivity for backhaul. In order to answer this question several measurements have been made to assess different aspect of live networks and compare them with the network operator's requirements. Different measurement protocols are utilized to evaluate some of the key network characteristics, such as throughput, jitter, packet loss, and delay. These measurement protocols are described in this thesis. Moreover, improving the bandwidth available in real-time (BART) measurement method was one of the main achievements of this thesis project. Evaluation of the measurement results indicates that fiber based access together with Internet connectivity would be the best and cheapest solution as a backhaul for small cell network in comparison with almost all of the other types of broadband access technologies. It should be noted that asymmetric digital subscriber line (ADSL) and cable- TV access networks proved to be unable to meet the requirements for small cell backhaul. This project gives a clear picture of the current broadband access network infrastructure's attributes and highlights the possibility of reducing backhaul costs by using broadband Internet connectivity as a backhaul transport option. / Dagens snabbt ökande mobilia datatrafik gör att nätverksoperatörerna behöver utöka både täckning och kapacitet hos sina nät. Att tillgodose båda dessa behov är en utmaning. Ett krav är kostnadseffektiva transporter via heterogena nätverk. För att uppfylla detta utreder många operatörer möjligheten att använda Internet-baserad returtrafik (backhaul) för småceller. Detta examensarbete utreder huruvida kraven för småceller kan uppfyllas genom att utnyttja en Internet-baserad returtrafik. För att kunna besvara denna fråga har flera mätningar utförts i syfte att bedöma olika aspekter av verkliga nätverk och jämföra dem med nätverksoperatörens krav. Olika mätprotokoll utnyttjas för att utvärdera några av de viktigaste egenskaperna hos nätet, såsom hastighet, jitter, paketförluster och förseningar. Dessa mätprotokoll beskrivs i dettta examensarbete. Dessutom/Vidare har metoden "bandbredd tillgänglig för realtidsmätningar" bandwidth available in real-time (BART) förbättrats. Utvärdering av mätresultaten visar att fiberbaserad access tillsammans med Internetanslutning är den bästa och billigaste returtrafiklösningen för småcellsnätverk för nästan alla olika typerna av bredbandsteknik, förutom för (asymmetric digital subscriber line) ADSL och kabelaccessnät. Detta projekt ger en tydlig bild av den aktuella nätinfrastrukturens egenskaper och möjligheten att reducera returtrafik-kostnaderna genom att använd bredbandsanslutning med Internet som transport kostnader.

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