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Optical amplifiers are developed to boost up the performance of the communication systems. Amplifiers such as erbium doped fiber amplifier (EDFA), RAMAN and semiconductor optical amplifier (SOA) are used for this purpose. It is mandatory to use optical amplifiers for signal transmission to long distances. In this paper, the hybrid optical amplifier EDFA-RAMAN-EDFA is proposed to enhance the signal quality received at receiver end and to initiate the efficient transmission of 8 × 10 Gbps transmission speed for wavelength division multiplexed (WDM) system. The proposed mechanism is evaluated with respect to various parameters such as quality factor, eye-height, and bit error rate (BER) and eye diagram considering various values of transmission distance ranging from 100 to 200 km. The analysis shows that the proposed mechanism has better quality factor value and minimum BER value than the traditional approach. Wider eye opening for proposed technique represents that the distortions produced in the system are least. [ABSTRACT FROM AUTHOR]

Fiber wireless (Fi-Wi) communication network is the amalgamation of optical and wireless access networks, which provides better bandwidth for achieving efficient data transmission. Medium access control (MAC) protocols are used in the wireless network for controlling the data flow from the transmitter to the receiver end. The delay produced by these protocols tells about the system efficiency. This paper shows a Fi-Wi system in the long-term evaluation-advanced (LTE-A) environment, which incorporates the dependency of delay generated by the specific MAC protocols during the transmission process. This paper aimed to scrutinize the effects of Carrier Sense Multiplexing Access with Collision Detection (CSMA/CD), Carrier Sense Multiplexing Access with Collision Avoidance (CSMA/CA) and Slotted ALOHA on the performance of the Fi-Wi system. Free space optical (FSO) channel is incorporated to forward the data to user end. In such system, the optical signal is multiplexed using the Orthogonal Frequency Division Multiplexing (OFDM) technique and finally the data are fetched at the receiver end and different criterions such eye-height, Q-factor and bit error rate are evaluated. Simulation results are performed using MATLAB software. The comparative analysis is also performed in terms of data transmission efficiency, delay and throughput of MAC protocols. This shows the effective results of the proposed system according to the delay produced by MAC protocols. [ABSTRACT FROM AUTHOR]

Wireless Sensor Networks (WSNs) have come across several things which include collecting data, handling data and distribution for super visioning specific applications such as the services needed, managing anything that occurred naturally, etc. They totally rely on applications. Therefore, the WSNs are classified under major networks. This is very essential. It can be defined as a network of networks that helps in proper flow of data. The main characteristics of WSN include its continuous changes in topologies, connected nodes with several chips and tunic routing protocol. There should be the better utilization of the available resources so that its life span may exceed. There should be an effective usage of available assets to avoid the waste. In our research, we propose a hybrid approach, namely, the Power Control Tree-Based Cluster (PCTBC) to identify the Sybil attacks in WSNs. It employs several stages structured clustering of nodes based on position and identity verification. This approach is utilized for the usage of energy consumption, effectiveness of detecting Sybil attacks inside clusters. The main aspects put into consideration are the efficient routing protocol of the distance between the hops and the energy power remains, where the distance between the hops is being computed using the Received Signal Strength Indication (RSSI) and also the packet transmission can be properly tuned on the basis of the distance. Also, the proposed approach considers the energy consumption for the transmission of the defined packet. [ABSTRACT FROM AUTHOR]

In this paper, link fault tolerant algorithms (LFTAs) are employed for optimization of blocking performance in optical burst switching (OBS) networks for dynamic establishment of wavelength-routed lightpaths. This paper presents two algorithms: link fault tolerance algorithm for least congestion (LFTALC) and link fault tolerance algorithm for optimized blocking (LFTAOB). In former algorithm, the path with least congestion is selected and in the latter algorithm the path with least blocking probability is selected and then both the algorithms check for the availability of fault on the links present in the selected path. The findings indicate that methods of developing link based fault tolerant algorithms keep good performance and fairness among all the connections. The key advantage of these proposed algorithms as compared to routing and wavelength assignment algorithm is that these are very simple in nature and require less service disruption time. [ABSTRACT FROM AUTHOR]

In this paper, fallacious node algorithm is formulated for performance enhancement of an optical-burst-switching (OBS) network. With the procedural and observational analysis, we have demonstrated that the blocking probability is extremely unnoticeable, during a call establishment, while collectively discarding the faulty nodes from the selected paths. There may be distinguishing values of blocking probability because of random value of congestion on each path. The blocking probability is restrained so as not to be more than 10 % on several values on traffic and congestion. The blocking probability diminishes and becomes imperceptible with the incorporation of fallacious node algorithm and subsequently the performance of optical network is highly aggrandized. Thus the fallacious node algorithm manifests incredible prospects for optical networks as the key features such as the accessibility; sustainability and reliability of the network are highly appreciated and upgraded. [ABSTRACT FROM AUTHOR]