124 research outputs found

    History of communication in Malaysia (1940-2008)

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    The Second World War was, in some ways, one of the lowest points in Malaysia's history. Japanese forces landed on the northeast border of Malaya on 8 December 194 1 and, in one month, succeeded in establishing their control of both Peninsula Malaya and Sabah and Sarawak. On 15 March 1942, Singapore surrendered. Singapore was renamed Shonan and became the centre of a regional administrative headquarters that incorporated the Straits Settlements, and the Federated Malay States and Sumatra. Much like the British who had installed residents in the Malay ruling houses fifty years earlier, the Japanese appointed local governors to each state. The only difference was that this time, it was the Sultans who were placed in the positions of advisors. The Unfederated Malay States, Perlis, Kedah, Kelantan and Terengganu found themselves back under the sovereignty of Thailand in 1942, when Thailand declared war on Britain and the USA. Most large scale economic activities grounded to a halt during the period of the War. The production of tin which was already falling before the War stopped almost completely. People turned their occupation away from the cultivation of commercial crops, concentrating instead on planting rice and vegetables to ensure they did not go hungry. [1

    3G telecommunication technology in Malaysia

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    3G is the third generation of mobile phone standards and technology, after 2G. It is based on the International Telecommunication Union (ITU) family of standards under the International Mobile Telecommunications programme, "IMT- 2000". 3G technologies enable network operators to offer users a wider range of more advanced services while achieving greater network capacity through improved spectral efficiency. Services include wide-area wireless voice telephony and broadband wireless data, all in a mobile environment. Typically, they provide service at 5-10 Mb per second

    High frequency band communication application in Malaysia

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    High frequency (HF) radio frequencies are between 3 and 30 MHz.[1] Also known as the decameter band or decameter wave as the wavelengths range from one to ten decameters. Shortwave (2.310 - 25.820 MHz)[1] overlaps and is slightly lower than HF. Since the ionosphere often reflects HF radio waves quite well (a phenomenon known as skywave), this range is extensively used for medium and long range terrestrial radio communication. However, suitability of this portion of the spectrum for such communication varies greatly with a complex combination of factors[1]: • Sunlight/darkness at site of transmission and reception • Transmitter/receiver proximity to terminator • Season • Sunspot cycle • Solar activity • Polar aurora • Maximum usable frequency • Lowest usable high frequency • Frequency of operation within the HF rang

    Characteristics and application of the asymmetric slab waveguide in optical integrated circuit

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    In this chapter, consists of demand in optical networking for photonic components that meet performance criteria as well as economic requirements has opened the door for novel technologies capable of high-yield low cost manufacturing while delivering high performance and enabling unique functions. The most promising new technologies are based on integrated optics. Integration permits the parallel production of complex multif unction photonic circuit on asymmetric slab waveguide. This kind of waveguide has very important role for designing the integrated optical circuit. To obtain the high performance function, we need to observe the waveguide characteristic in transverse mode (TE mode and TM m ode), the waveguide structure, and materials. Hence, a thoroughly study on asymmetric slab waveguide is essential in future implementation of optical devices in optical network. Integrated optics is the technology of constructing optic devices and networks on substrates [1]. Integrated optics offers the capability of combining optics and electronic components on a single substrate to produce functional systems or subsystems. Within an integrated optic network, light is transferred between components by a rectangular dielectric-slab waveguide

    Dynamic bandwidth allocation algorithm for long reach passive optical network

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    Next generation broadband access networks are gaining more interests from many key players in this field. The demands for longer reach and higher bandwidth are among the driving factors for such network as it can reach wider area up to 100 km, even beyond; has enhanced bandwidth capacity and transmission speed, but with low cost and energy consumption. One promising candidate is long reach passive optical network, a simplified network with reduced number of network elements, equipment interfaces, and even nodes; which leads to a significant reduction in the network’s capital expenditure and operational expenditure. Outcome of an extended reach often results in increased propagation delay of dynamic bandwidth allocation messages exchange between the optical line terminals and optical network units, leading to the degradations of bandwidth allocation and quality of service support. Therefore, an effective bandwidth allocation algorithm with appropriate service interval setup for a long reach network is proposed to ensure the delay is maintained under ITU-T G.987.1 standard requirement. An existing algorithm is improved in terms of service interval so that it can perform well beyond 100 km. Findings show that the improved algorithm can reduce the mean delay of high priority traffic classes for distance up to 140 km

    Optimization of system’s parameters for wavelength conversion of E-band signals

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    Current and future wireless communication systems are designed to achieve the user’s demands such as high data rate and high speed with low latency and simultaneously to save bandwidth and spectrum. In 5G and 6G networks, a high speed of transmitting and switching is required for internet of things (IoT) applications with higher capacity. To achieve these requirements a semiconductor optical amplifier (SOA) is considered as a wavelength converter to transmit a signal with an orthogonal frequency division multiplexing with subcarrier power modulation (OFDM-SPM). It exploits the subcarrier’s power in conventional OFDM block in order to send additional bits beside the normally transmitted bits. In this paper, we optimized the SOA’s parameters to have efficient wavelength conversion process. These parameters are included the injection current (IC) of SOA, power of pump and probe signals. A 7 Gbps OFDM-SPM signal with a millimeter waves (MMW) carrier of 80 GHz is considered for signal switching. The simulation results investigated and analyzed the performance of the designed system in terms of error vector magnitude (EVM), bit error rate (BER) and optical signal-to-noise ratio (OSNR). The optimum value of IC is 0.6 A while probe power is 9.45 and 8.9 dBm for pump power. The simulation is executed by virtual photonic integrated (VPI) software

    Fundamental Review to Ozone Gas Sensing Using Optical Fibre Sensors

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    The manuscript is a review of basic essentials to ozone gas sensing with optical methods. Optical methods are employed to monitor optical absorption, emission, reflectance and scattering of gas samples at specific wavelengths of light spectrum. In the light of their importance in numerous disciplines in analytical sciences, necessary integral information that serves both as a basis and reference material for intending researchers and others in the field is inevitable. This review provides insight into necessary essentials to gas sensing with optical fibre sensors. Ozone gas is chosen as a reference gas. Simulation results for ozone gas absorption cross section in the ultraviolet (UV) region of the spectrum using spectralcalc.com simulation have also been included

    QoS support with taguchi method in simulation modeling hybrid architecture of optical and multihop wireless ad hoc networks

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    Majority of the resource consumption is consumed for their operation in the access network of mobile wireless part because of its dynamic topology and limited range of each mobile host's wireless transmissions. This paper presents a technique using OMNeT++ software for building a design of experiment simulation model with Taguchi optimization method supported mobile circumstantial network (MANET) of AODVUU communication protocol to be apply into collaborate multiple layers framework of deploy over passive optical network (PON) referred to as the walk Mobile Hybrid optical wireless access network (erL-MMHOWAN). it's to guage the network quality of service effectively that take into account variety of nodes over that the Edouard Manet could operate. Its performance is examined on the known performance metrics just like the network capability and energy consumption. Simulation result shows for the random mobile property during this convergence of heterogeneous optical wireless network will perform higher with the optimized front-end wireless circumstantial

    Energy Efficient Frame Structure for Gigabit Passive Optical Networks

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    Increasing power consumption in information and communication access networks is one of the major cause of greenhouse gas emissions. These emissions are harmful to life on earth. Passive Optical Networks (PONs) are energy efficient but the broadcast nature of downstream traffic may cause of huge unnecessary processing of frames by the optical network units and result in significant energy wastage. Bi-PON technique tried to solve this problem by changing the XGPON / GPON frame structure to an interleaved pattern but also required additional hardware changings at the optical network units.  In this study, we have tried to achieve the same objective by making a few changings in the GPON frame structure without modifying the existing hardware structure. The simulation results show that 25.25% processing energy of an ONU can be saved by incorporating these changes

    Efficient P2P data dissemination in integrated optical and wireless networks with Taguchi method

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    The Quality of Service (QoS) resource consumption is always the tricky problem and also the on-going issue in the access network of mobile wireless part because of its dynamic nature of network wireless transmissions. It is very critical for the infrastructure-less wireless mobile ad hoc network that is distributed while interconnects in a peer-to-peer manner. Toward resolve the problem, Taguchi method optimization of mobile ad hoc routing (AODVUU) is applied in integrated optical and wireless networks called the adLMMHOWAN. Practically, this technique was carry out using OMNeT++ software by building a simulation based optimization through design of experiment. Its QoS network performance is examined based on packet delivery ratio (PDR) metric and packet loss probabilities (PLP) metric that consider the scenario of variation number of nodes. During the performing stage with random mobile connectivity based on improvement in optimized front-end wireless domain of AODVUU routing, the result is performing better when compared with previous study called the oRia scheme with the improvement of 14.1% PDR and 43.3% PLP in this convergence of heterogeneous optical wireless network
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