Design and Optimization of FTTH Architecture

Recently, the growth of Internet and uses of digital contents have significantly increased the demand for high-speed access network. Similar cases are also seen for the use of intranet and extranet services. The limitation of current access network such as the asymmetric digital subscriber line (ADSL) in terms of low bit rate and short of coverage span resulted in the exploration on fibre access scenario. Fibre-tothe- home (FTTH) brings the broadband access network capabilities directly to the customer premises with high splitting ratio and wide fibre span. It is seen as the linchpin technology to enable the future applications such as voice, video and data run, satisfying the ever-increasing need for bandwidth. This thesis shows the study of FTTH access network based on passive optical network (PON). The two types of FTTH; A-PON and Super-PON have been studied thoroughly to optimize their architecture to help network engineers in designing the system. The cost analysis is also carried out. The simulation is done using OptSim 3.0 and the result is verified with the experiment in the laboratory. It is found that the optimum configuration of a A-PON FTTH access systems with the bit rate of 2Gb/s with the use of 32 branching number is at the distance of 20 km. The power enhancement offered by Erbium-doped Fibre Amplifier (EDFA) provides for large distribution branches (thus the subscribers) and the length of fibre span can be extended up to 100 km

A performance study of routing protocols for mobile grid environment

Integration of mobile wireless consumer devices into the Grid initially seems unlikely due to limitation such as CPU performance,small secondary storage, heightened battery consumption sensitivity and unreliable low-bandwidth communication. The current grid architecture and algorithm also do not take into account the mobile computing environment since mobile devices have not been seriously considered as valid computing resources or interfaces in grid communities. This paper presents the results of simulation done in identifying a suitable ad hoc routing protocol that can be used for the target grid application in mobile environment. The simulation comparing three ad hoc routing protocols named DSDV, DSR and AODV

Performance and cost comparisons for A-PON and S-PON FTTH systems

The high cost of fibers has always been a main concern as to why they have not been deployed in access networks. As the fiber technology is maturing, the costs fibers are slowly decreasing, and hence the above issue is no longer an issue. This paper discusses the performance comparison of A-PON and S-PON FTTH architecture as well as its cost. It is established that the relationship between the fiber span and distributed area offered by S-PON is due to the power enhancement boosted by an amplifier. Meanwhile the cost of S-PON will be reasonable if there are enough users sharing the same feeder line or transmission path

Performance evaluation of IDSDV over DSDV for specific traffic pattern.

Mobile Ad-Hoc Networks is an infrastructure less mobile network having mobile nodes entering and leaving the network freely at any time. The decentralized nature requires every node plays a router role and have its own routing table to other nodes in the network. Many categories of routing protocol exists, in this paper we studies one that is based on routing strategy that employs proactive approach namely DSDV and IDSDV. DSDV protocol is known to have a low performance in packet delivery ratio due to stale route problem. In case of link breakage, it is incapable of providing an alternative route. IDSDV addresses this issue by introducing a novel message exchange scheme for reconstruction of broken route, to allow packet to be transmitter and thus increases the performance. Many have reported this improvement, but none of the tests were meant for individual traffics pattern. Based on selected metrics, we re-evaluate the performance of IDSDV over DSDV for TCP traffic, with respect to chosen mobility model, varying number of nodes, pause time and nodes speed. Simulation result shows that the performance of IDSDV outclasses DSDV with respect to routing overhead metric. Meanwhile for packet delivery fraction metric, both protocols are almost equally performed

Quantum time task scheduling technique in novel hybrid shortest job first and round robin

In a cloud computing environment, there are huge number of tasks with different computing requirements need to be scheduled and provisioned to the various resources within different capabilities. Thus, the mapping between users and resources is crucial so that the performance could be improved. The hybrid algorithm Shortest-Job-First (SJF) and Round Robin (RR) are expected to address all the concerns in scheduling task namely response time, waiting time and turnaround time simultaneously. Existing schedulers has been focused on those parameters but starvation problems are mostly not their major concern. Therefore, this study attempts to produce a better performance of hybrid algorithm through the integration of two traditional algorithms namely SJF and RR with dynamic quantum (SRDQ). Our proposed SRDQ with the best quantum time approach apparently reduces the longer waiting time when involves with a large cloudlet. Thus, it is suitable for the cloud computing environments where the resource hunger applications are normally provisioned

Performance and cost comparisons for A-PON and S-PON FTTH systems

The high cost of fibers has always been a main concern as to why they have not been deployed in access networks. As the fiber technology is maturing, the costs fibers are slowly decreasing, and hence the above issue is no longer an issue. This paper discusses the performance comparison of A-PON and S-PON FTTH architecture as well as its cost. It is established that the relationship between the fiber span and distributed area offered by S-PON is due to the power enhancement boosted by an amplifier. Meanwhile the cost of S-PON will be reasonable if there are enough users sharing the same feeder line or transmission path

Performance evaluation of task scheduling using hybrid meta-heuristic in heterogeneous cloud environment

Cloud computing is a ubiquitous platform that offers a wide range of online services to clients including but not limited to information and software over the Internet. It is an essential role of cloud computing to enable sharing of resources on-demand over the network including servers, applications, storage, services, and database to the end-users who are remotely connected to the network. Task scheduling is one of the significant function in the cloud computing environment which plays a vital role to sustain the performance of the system and improve its efficiency. Task scheduling is considered as an NP-complete problem in many contexts, however, the heterogeneity of resources in the cloud environment negatively influence on the job scheduling process. Furthermore, on the other side, the heuristic algorithms have satisfying performance but unable to achieve the desired level of efficiency for optimizing the scheduling in a cloud environment. Thus, this paper aims at evaluating the effectiveness of the hybrid meta-heuristic that incorporate genetic algorithm along with DE algorithm (GA-DE) in terms of make-span. In addition, the paper also intends to enhance the performance of the task scheduling in the heterogeneous cloud environment exploiting the scientific workflows (Cybershake, Montage, and Epigenomics). The proposed algorithm (GA-DE) has been compared against three heuristic algorithms, namely: HEFT-Upward Rank, HEFT – Downward Rank, and HEFT – Level Rank. The simulation results prove that the proposed algorithm (GA-DE) outperforms the other existing algorithms in all cases in terms of make-span

Performance comparison of routing protocols for mobile grid environment.

Integration of mobile wireless consumer devices into the Grid initially seems unlikely due to limitation such as CPU performance, small secondary storage, heightened battery consumption sensitivity and unreliable low-bandwidth communication. The current grid architecture and algorithm also do not take into account the mobile computing environment since mobile devices have not been seriously considered as valid computing resources or interfaces in grid communities. This paper presents the results of simulation done in identifying suitable ad hoc routing protocol that can be used for the target mobile grid application. The simulation comparing three ad hoc routing protocols named DSDV, DSR and AODV

Trust-aware scheduling for tasks with precedence constraints in heterogeneous distributed computing

Demands for reliability in distributed computing systems have become extremely important now a days due to strong requirements imposed by the dynamic behaviour of user and resource communities. With the increasing number of entities in the distributed systems, inadequate information and unsuccessful accessibility have becoming critical factors that impact system performance. We present an adaptive scheduling which attempts to improve system reliability. Specifically, our scheduling approach combines trust-based matching scheme with robust mapping rules to deal with diverse processing requirements and heterogeneous resources. Simulation experiments proved the efficacy of our approach in achieving better system performance and implicitly help to gain reliable and cost-effective computation

CNDS-rules and pattern based signal recovery for multi-level signal decision making

This paper focuses on the pattern based decision making over a multilevel symbol coding, Duty-cycle Division Multiplexing (DCDM). The pattern based decision making is used to increase the bit generation reliability at the receiver. It is used in conjunction with the existing rules-based decision making, which leads to better Bit Error Rate (BER). In this study, a reference pattern is first established from a combination of signals of multiple users’ data. Subsequently, a new signal is generated according to the established patterns. This signal is then transmitted over the optical medium. At the receiver, signal validation and bit generation are then taking place based on the DCDM regeneration rules. Due to the signal impairments, the received signal will be corrupted. The impairments may cause the signal patterns to differ from the transmitted patterns. These non-conforming patterns are classified as invalid patterns, which are then subjected to the error evaluation and pattern re-mapping. In this paper for the first time we have used a new pattern based decision making in order to increase the reliability of bit sequence generation at the receiver, which leads to better BER