Matching Items (7)

Ethernet passive optical network dynamic bandwidth allocation study

Description

Fiber-Wireless (FiWi) network is the future network configuration that uses optical fiber as backbone transmission media and enables wireless network for the end user. Our study focuses on the Dynamic

Fiber-Wireless (FiWi) network is the future network configuration that uses optical fiber as backbone transmission media and enables wireless network for the end user. Our study focuses on the Dynamic Bandwidth Allocation (DBA) algorithm for EPON upstream transmission. DBA, if designed properly, can dramatically improve the packet transmission delay and overall bandwidth utilization. With new DBA components coming out in research, a comprehensive study of DBA is conducted in this thesis, adding in Double Phase Polling coupled with novel Limited with Share credits Excess distribution method. By conducting a series simulation of DBAs using different components, we found out that grant sizing has the strongest impact on average packet delay and grant scheduling also has a significant impact on the average packet delay; grant scheduling has the strongest impact on the stability limit or maximum achievable channel utilization. Whereas the grant sizing only has a modest impact on the stability limit; the SPD grant scheduling policy in the Double Phase Polling scheduling framework coupled with Limited with Share credits Excess distribution grant sizing produced both the lowest average packet delay and the highest stability limit.

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Created

Date Created
  • 2011

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Design and performance analysis of fiber wireless networks

Description

A Fiber-Wireless (FiWi) network integrates a passive optical network (PON) with wireless mesh networks (WMNs) to provide high speed backhaul via the PON while offering the flexibility and mobility of

A Fiber-Wireless (FiWi) network integrates a passive optical network (PON) with wireless mesh networks (WMNs) to provide high speed backhaul via the PON while offering the flexibility and mobility of a WMN. Generally, increasing the size of a WMN leads to higher wireless interference and longer packet delays. The partitioning of a large WMN into several smaller WMN clusters, whereby each cluster is served by an Optical Network Unit (ONU) of the PON, is examined. Existing WMN throughput-delay analysis techniques considering the mean load of the nodes at a given hop distance from a gateway (ONU) are unsuitable for the heterogeneous nodal traffic loads arising from clustering. A simple analytical queuing model that considers the individual node loads to accurately characterize the throughput-delay performance of a clustered FiWi network is introduced. The accuracy of the model is verified through extensive simulations. It is found that with sufficient PON bandwidth, clustering substantially improves the FiWi network throughput-delay performance by employing the model to examine the impact of the number of clusters on the network throughput-delay performance. Different traffic models and network designs are also studied to improve the FiWi network performance.

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Created

Date Created
  • 2015

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MAC-layer algorithm designs for hybrid access network supporting SDN principles

Description

Access Networks provide the backbone to the Internet connecting the end-users to

the core network thus forming the most important segment for connectivity. Access

Networks have multiple physical layer medium ranging from

Access Networks provide the backbone to the Internet connecting the end-users to

the core network thus forming the most important segment for connectivity. Access

Networks have multiple physical layer medium ranging from fiber cables, to DSL links

and Wireless nodes, creating practically-used hybrid access networks. We explore the

hybrid access network at the Medium ACcess (MAC) Layer which receives packets

segregated as data and control packets, thus providing the needed decoupling of data

and control plane. We utilize the Software Defined Networking (SDN) principle of

centralized processing with segregated data and control plane to further extend the

usability of our algorithms. This dissertation introduces novel techniques in Dynamic

Bandwidth allocation, control message scheduling policy, flow control techniques and

Grouping techniques to provide improved performance in Hybrid Passive Optical Networks (PON) such as PON-xDSL, FiWi etc. Finally, we study the different types of

software defined algorithms in access networks and describe the various open challenges and research directions.

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Created

Date Created
  • 2015

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Long term evolution backhaul over ethernet passive optical network: an analysis study

Description

LTE (Long Term Evolution) represents an emerging technology that will change how service providers backhaul user traffic to their infrastructure over IP networks. To support growing mobile bandwidth demand, an

LTE (Long Term Evolution) represents an emerging technology that will change how service providers backhaul user traffic to their infrastructure over IP networks. To support growing mobile bandwidth demand, an EPON backhaul infrastructure will make possible realtime high bandwidth applications. LTE backhaul planning and deployment scenarios are important factors to network success. In this thesis, we are going to study the effect of LTE backhaul on Optical network, in an attempt to interoperate Fiber and Wireless networks. This project is based on traffic forecast for the LTE networks. Traffic models are studied and gathered from literature to reflect applications accurately. Careful capacity planning of the mobile backhaul is going to bring a better experience for LTE users, in terms of bit rates and latency they can expect, while allowing the network operators to spend their funds effectively.

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Date Created
  • 2014

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Efficient routing and resource sharing mechanisms for hybrid optical-wireless access networks

Description

The integration of passive optical networks (PONs) and wireless mesh networks (WMNs) into Fiber-Wireless (FiWi) networks has recently emerged as a promising strategy for

providing flexible network services at relative high

The integration of passive optical networks (PONs) and wireless mesh networks (WMNs) into Fiber-Wireless (FiWi) networks has recently emerged as a promising strategy for

providing flexible network services at relative high transmission rates. This work investigates the effectiveness of localized routing that prioritizes transmissions over the local gateway to the optical network and avoids wireless packet transmissions in radio zones that do not contain the packet source or destination. Existing routing schemes for FiWi networks consider mainly hop-count and delay metrics over a flat WMN node topology and do not specifically prioritize the local network structure. The combination of clustered and localized routing (CluLoR) performs better in terms of throughput-delay compared to routing schemes that are based on minimum hop-count which do not consider traffic localization. Subsequently, this work also investigates the packet delays when relatively low-rate traffic that has traversed a wireless network is mixed with conventional high-rate PON-only traffic. A range of different FiWi network architectures with different dynamic bandwidth allocation (DBA) mechanisms is considered. The grouping of the optical network units (ONUs) in the double-phase polling (DPP) DBA mechanism in long-range (order of 100~Km) FiWi networks is closely examined, and a novel grouping by cycle length (GCL) strategy that achieves favorable packet delay performance is introduced. At the end, this work proposes a novel backhaul network architecture based on a Smart Gateway (Sm-GW) between the small cell base stations (e.g., LTE eNBs) and the conventional backhaul gateways, e.g., LTE Servicing/Packet Gateway (S/P-GW). The Sm-GW accommodates flexible number of small cells while reducing the infrastructure requirements at the S-GW of LTE backhaul. In contrast to existing methods, the proposed Sm-GW incorporates the scheduling mechanisms to achieve the network fairness while sharing the resources among all the connected small cells base stations.

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Created

Date Created
  • 2016

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Object-based PON access and tandem networking

Description

The upstream transmission of bulk data files in Ethernet passive optical networks (EPONs) arises from a number of applications, such as data back-up and multimedia file upload. Existing upstream transmission

The upstream transmission of bulk data files in Ethernet passive optical networks (EPONs) arises from a number of applications, such as data back-up and multimedia file upload. Existing upstream transmission approaches lead to severe delays for conventional packet traffic when best-effort file and packet traffic are mixed. I propose and evaluate an exclusive interval for bulk transfer (EIBT) transmission strategy that reserves an EIBT for file traffic in an EPON polling cycle. I optimize the duration of the EIBT to minimize a weighted sum of packet and file delays. Through mathematical delay analysis and verifying simulation, it is demonstrated that the EIBT approach preserves small delays for packet traffic while efficiently serving bulk data file transfers. Dynamic circuits are well suited for applications that require predictable service with a constant bit rate for a prescribed period of time, such as demanding e-science applications. Past research on upstream transmission in passive optical networks (PONs) has mainly considered packet-switched traffic and has focused on optimizing packet-level performance metrics, such as reducing mean delay. This study proposes and evaluates a dynamic circuit and packet PON (DyCaPPON) that provides dynamic circuits along with packet-switched service. DyCaPPON provides (i) flexible packet-switched service through dynamic bandwidth allocation in periodic polling cycles, and (ii) consistent circuit service by allocating each active circuit a fixed-duration upstream transmission window during each fixed-duration polling cycle. I analyze circuit-level performance metrics, including the blocking probability of dynamic circuit requests in DyCaPPON through a stochastic knapsack-based analysis. Through this analysis I also determine the bandwidth occupied by admitted circuits. The remaining bandwidth is available for packet traffic and I analyze the resulting mean delay of packet traffic. Through extensive numerical evaluations and verifying simulations, the circuit blocking and packet delay trade-offs in DyCaPPON is demonstrated. An extended version of the DyCaPPON designed for light traffic situation is introduced in this article as well.

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  • 2014

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Analytical approach to dynamic bandwidth allocation algorithms used in LRPON

Description

With internet traffic being bursty in nature, Dynamic Bandwidth Allocation(DBA) Algorithms have always been very important for any broadband access network to utilize the available bandwidth effciently. It is no

With internet traffic being bursty in nature, Dynamic Bandwidth Allocation(DBA) Algorithms have always been very important for any broadband access network to utilize the available bandwidth effciently. It is no different for Passive Optical Networks(PON), which are networks based on fiber optics in the physical layer of TCP/IP stack or OSI model, which in turn increases the bandwidth in the upper layers. The work in this thesis covers general description of basic DBA Schemes and mathematical derivations that have been established in research. We introduce a Novel Survey Topology that classifes DBA schemes based on their functionality. The novel perspective of classification will be useful in determining which scheme will best suit consumer's needs. We classify DBA as Direct, Intelligent and Predictive back on its computation method and we are able to qualitatively describe their delay and throughput bounds. Also we describe a recently developed DBA Scheme, Multi-thread polling(MTP) used in LRPON and describes the different viewpoints and issues and consequently introduce a novel technique Parallel Polling that overcomes most of issues faced in MTP and that promises better delay performance for LRPON.

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Created

Date Created
  • 2012