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

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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 EPON backhaul infrastructure will make possible realtime high bandwidth

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.
Date Created
2014
Agent

Resource allocation for video streaming in multi-user wireless networks

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Description
Survey indicates a rise of 81% in mobile data usage in the year 2013. A fair share of this total data demand can be attributed to video streaming. The encoding structure of videos, introduces nuances that can be utilized to

Survey indicates a rise of 81% in mobile data usage in the year 2013. A fair share of this total data demand can be attributed to video streaming. The encoding structure of videos, introduces nuances that can be utilized to ensure a fair and optimal means of streaming the video data. This dissertation proposes a novel user and packet scheduling algorithm that guarantees a fair allocation of resources. MS-SSIM index

is used to calculate the mean opinion score (DMOS) to evaluate the quality of the received video. Simulations indicate that the proposed algorithm outperforms existing algorithms in the literature.
Date Created
2014
Agent

Performance models for LTE-advanced random access

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Description
LTE-Advanced networks employ random access based on preambles

transmitted according to multi-channel slotted Aloha principles. The

random access is controlled through a limit W on the number of

transmission attempts and a timeout period for uniform backoff after a

collision. We model the LTE-Advanced

LTE-Advanced networks employ random access based on preambles

transmitted according to multi-channel slotted Aloha principles. The

random access is controlled through a limit W on the number of

transmission attempts and a timeout period for uniform backoff after a

collision. We model the LTE-Advanced random access system by formulating

the equilibrium condition for the ratio of the number of requests

successful within the permitted number of transmission attempts to those

successful in one attempt. We prove that for W≤8 there is only one

equilibrium operating point and for W≥9 there are three operating

points if the request load ρ is between load boundaries ρ1

and ρ2. We analytically identify these load boundaries as well as

the corresponding system operating points. We analyze the throughput and

delay of successful requests at the operating points and validate the

analytical results through simulations. Further, we generalize the

results using a steady-state equilibrium based approach and develop

models for single-channel and multi-channel systems, incorporating the

barring probability PB. Ultimately, we identify the de-correlating

effect of parameters O, PB, and Tomax and introduce the

Poissonization effect due to the backlogged requests in a slot. We

investigate the impact of Poissonization on different traffic and

conclude this thesis.
Date Created
2014
Agent

Relationships among personal characteristics, self-efficacy, and conceptual knowledge of circuit analysis of community college engineering students

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Description
Conceptual knowledge and self-efficacy are two research topics that are well-established at universities, however very little has been investigated about these at the community college. A sample of thirty-seven students enrolled in three introductory circuit analysis classes at a large

Conceptual knowledge and self-efficacy are two research topics that are well-established at universities, however very little has been investigated about these at the community college. A sample of thirty-seven students enrolled in three introductory circuit analysis classes at a large southwestern community college was used to answer questions about conceptual knowledge and self-efficacy of community college engineering students. Measures included a demographic survey and a pre/post three-tiered concept inventory to evaluate student conceptual knowledge of basic DC circuit analysis and self-efficacy for circuit analysis. A group effect was present in the data, so descriptive statistics were used to investigate the relationships among students' personal and academic characteristics and conceptual knowledge of circuit analysis. The a priori attribute approach was used to qualitatively investigate misconceptions students have for circuit analysis. The results suggest that students who take more credit hours score higher on a test of conceptual knowledge of circuit analysis, however additional research is required to confirm this, due to the group effect. No new misconceptions were identified. In addition to these, one group of students received more time to practice using the concepts. Consequently, that group scored higher on the concept inventory, possibly indicating that students who have extra practice time may score higher on a test of conceptual knowledge of circuit analysis. Correlation analysis was used to identify relationships among students' personal and academic characteristics and self-efficacy for circuit analysis, as well as to investigate the relationship between self-efficacy for circuit analysis and conceptual knowledge of circuit analysis. Subject's father's education level was found to be inversely correlated with self-efficacy for circuit analysis, and subject's age was found to be directly correlated with self-efficacy for circuit analysis. Finally, self-efficacy for circuit analysis was found to be positively correlated with conceptual knowledge of circuit analysis.
Date Created
2014
Agent

Voice over LTE study and test strategy definition

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Description
Voice and other circuit switched services in a LTE deployment can be based on a Circuit Switched Fall Back mechanism or on the upcoming Voice Over LTE option. Voice Over LTE option can be used with its SIP based signaling

Voice and other circuit switched services in a LTE deployment can be based on a Circuit Switched Fall Back mechanism or on the upcoming Voice Over LTE option. Voice Over LTE option can be used with its SIP based signaling to route voice calls and other circuit switched services over the LTE's packet switched core. The main issue that is faced though is the validation of this approach before the deployment over commercial network. The test strategy devised as a result of this work will be able to visit corner scenarios and error sensitive services, so that signaling involved can be verified to ensure a robust deployment of the Voice Over LTE network. Signaling test strategy is based on the observations made during a simulated Voice Over LTE call inside the lab in a controlled environment. Emergency services offered are carefully studied to devise a robust test strategy to make sure that any service failure is avoided. Other area were the service is routed via different protocol stack layer than it normally is in a legacy circuit switched core are identified and brought into the scope of the test strategy.
Date Created
2014
Agent

Estimation of cost-based channel occupancy in cognitive radio using sequential Monte Carlo methods

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Description
Dynamic channel selection in cognitive radio consists of two main phases. The first phase is spectrum sensing, during which the channels that are occupied by the primary users are detected. The second phase is channel selection, during which the state

Dynamic channel selection in cognitive radio consists of two main phases. The first phase is spectrum sensing, during which the channels that are occupied by the primary users are detected. The second phase is channel selection, during which the state of the channel to be used by the secondary user is estimated. The existing cognitive radio channel selection literature assumes perfect spectrum sensing. However, this assumption becomes problematic as the noise in the channels increases, resulting in high probability of false alarm and high probability of missed detection. This thesis proposes a solution to this problem by incorporating the estimated state of channel occupancy into a selection cost function. The problem of optimal single-channel selection in cognitive radio is considered. A unique approach to the channel selection problem is proposed which consists of first using a particle filter to estimate the state of channel occupancy and then using the estimated state with a cost function to select a single channel for transmission. The selection cost function provides a means of assessing the various combinations of unoccupied channels in terms of desirability. By minimizing the expected selection cost function over all possible channel occupancy combinations, the optimal hypothesis which identifies the optimal single channel is obtained. Several variations of the proposed cost-based channel selection approach are discussed and simulated in a variety of environments, ranging from low to high number of primary user channels, low to high levels of signal-to-noise ratios, and low to high levels of primary user traffic.
Date Created
2014
Agent

Object-based PON access and tandem networking

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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 approaches lead to severe delays for conventional packet traffic when

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.
Date Created
2014
Agent

New multi-nodal wireless communication system method

Description
The purpose of this paper is to introduce a new method of dividing wireless communication (such as the 802.11a/b/g
and cellular UMTS MAC protocols) across multiple unreliable communication links (such as Ethernet). The purpose is to introduce the appropriate hardware,

The purpose of this paper is to introduce a new method of dividing wireless communication (such as the 802.11a/b/g
and cellular UMTS MAC protocols) across multiple unreliable communication links (such as Ethernet). The purpose is to introduce the appropriate hardware, software, and system architecture required to provide the basis for a wireless system (using a 802.11a/b/g
and cellular protocols as a model) that can scale to support thousands of users simultaneously (say in a large office building, super chain store, etc.) or in a small, but very dense communication RF region. Elements of communication between a base station and a Mobile Station will be analyzed statistically to demonstrate higher throughput, fewer collisions and lower bit error rates (BER) with the given bandwidth defined by the 802.11n wireless specification (use of MIMO channels will be evaluated). A new network nodal paradigm will be presented. Alternative link layer communication techniques will be recommended and analyzed for the affect on mobile devices. The analysis will describe how the algorithms used by state machines implemented on Mobile Stations and Wi-Fi client devices will be influenced by new base station transmission behavior. New hardware design techniques that can be used to optimize this architecture as well as hardware design principles in regard to the minimal hardware functional blocks required to support such a system design will be described. Hardware design and verification simulation techniques to prove the hardware design will accommodate an acceptable level of performance to meet the strict timing as it relates to this new system architecture.
Date Created
2014
Agent

Large-scale wireless networks: stochastic geometry and ordering

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Description
Recently, the location of the nodes in wireless networks has been modeled as point processes. In this dissertation, various scenarios of wireless communications in large-scale networks modeled as point processes are considered. The first part of the dissertation considers signal

Recently, the location of the nodes in wireless networks has been modeled as point processes. In this dissertation, various scenarios of wireless communications in large-scale networks modeled as point processes are considered. The first part of the dissertation considers signal reception and detection problems with symmetric alpha stable noise which is from an interfering network modeled as a Poisson point process. For the signal reception problem, the performance of space-time coding (STC) over fading channels with alpha stable noise is studied. We derive pairwise error probability (PEP) of orthogonal STCs. For general STCs, we propose a maximum-likelihood (ML) receiver, and its approximation. The resulting asymptotically optimal receiver (AOR) does not depend on noise parameters and is computationally simple, and close to the ML performance. Then, signal detection in coexisting wireless sensor networks (WSNs) is considered. We define a binary hypothesis testing problem for the signal detection in coexisting WSNs. For the problem, we introduce the ML detector and simpler alternatives. The proposed mixed-fractional lower order moment (FLOM) detector is computationally simple and close to the ML performance. Stochastic orders are binary relations defined on probability. The second part of the dissertation introduces stochastic ordering of interferences in large-scale networks modeled as point processes. Since closed-form results for the interference distributions for such networks are only available in limited cases, it is of interest to compare network interferences using stochastic. In this dissertation, conditions on the fading distribution and path-loss model are given to establish stochastic ordering between interferences. Moreover, Laplace functional (LF) ordering is defined between point processes and applied for comparing interference. Then, the LF orderings of general classes of point processes are introduced. It is also shown that the LF ordering is preserved when independent operations such as marking, thinning, random translation, and superposition are applied. The LF ordering of point processes is a useful tool for comparing spatial deployments of wireless networks and can be used to establish comparisons of several performance metrics such as coverage probability, achievable rate, and resource allocation even when closed form expressions for such metrics are unavailable.
Date Created
2014
Agent

Design of a low power and delay multi-protocol switching system for I/O and network virtualization

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Description
Data centers connect a larger number of servers requiring IO and switches with low power and delay. Virtualization of IO and network is crucial for these servers, which run virtual processes for computing, storage, and apps. We propose using the

Data centers connect a larger number of servers requiring IO and switches with low power and delay. Virtualization of IO and network is crucial for these servers, which run virtual processes for computing, storage, and apps. We propose using the PCI Express (PCIe) protocol and a new PCIe switch fabric for IO and switch virtualization. The switch fabric has little data buffering, allowing up to 512 physical 10 Gb/s PCIe2.0 lanes to be connected via a switch fabric. The switch is scalable with adapters running multiple adaptation protocols, such as Ethernet over PCIe, PCIe over Internet, or FibreChannel over Ethernet. Such adaptation protocols allow integration of IO often required for disjoint datacenter applications such as storage and networking. The novel switch fabric based on space-time carrier sensing facilitates high bandwidth, low power, and low delay multi-protocol switching. To achieve Terabit switching, both time (high transmission speed) and space (multi-stage interconnection network) technologies are required. In this paper, we present the design of an up to 256 lanes Clos-network of multistage crossbar switch fabric for PCIe system. The switch core consists of 48 16x16 crossbar sub-switches. We also propose a new output contention resolution algorithm utilizing an out-of-band protocol of Request-To-Send (RTS), Clear-To-Send (CTS) before sending PCIe packets through the switch fabric. Preliminary power and delay estimates are provided.
Date Created
2013
Agent