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Duty Cycle Division Multiplexing (DCDM) has been shown to be able to improve utilization of the optical bandwidth. However, the challenge arises on its signal recovery at the receiver ends. Decision making protocol plays an important role to determine the correctness of its regenerated data. Previous approach regenerate inaccurate data due to its assumption that all received signals are valid. Thus, the automatic mapping is used in their decision process with no consideration on invalid signals. Due to this motivation, we design a new signal recovery protocol for DCDM. In this protocol, the signal properties such as amplitude level, distance between slots, number of slot change and probabilities of occurrence are used in order to discriminate the received signal into an appropriate data. The simulation is established through OptiSystem simulator and Matlab programming. It is observed that an improvement of the BER by 16.2 percent can be achieved using the new proposed protocol.

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Problem statement: Wireless technology has far growing with an increasing demand of the Wireless networking technologies recent years. The wireless access network and cellular networks are being used to support their need. It is usually connected to a wired backbone network. TCP is used to handle the congestion in wired network. However, it is not well suited for hybrid network consisting of wired and wireless networks. Packet loss occurs in wireless network mostly due to high bit error rate, varying in transmission length, or link failure. These scenarios are always misinterpreted by conventional TCP as a congestion loss. Hence, TCP sender performs congestion control which is unnecessary and leads to a poor network performance. Approach: A new algorithm proposed in this study is to differentiate the types of packet loss accurately. The algorithm will classify the packet loss and invoke proper correction mechanisms. Results: Our simulation results show the improvement of TCP performance as compared to the existing Selective-TCP and TCP NewReno. Conclusion: The proposed algorithm on classifying packet loss shows the improvement of TCP performance.

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.