95 research outputs found
Indoor Wireless Communications using Slotted ISMA protocols
No full textThe performance of the Slotted ISMA protocols in Rician fading channel for Indoor Wireless communications considering Pico Cellular systems have been analyzed in this thesis. The throughput of Slotted nonpersistant Inhibit Sense Multiple Access (np-ISMA), Slotted 1-persistent ISMA (1p-ISMA) and Slotted np-ISMA\CD (Collision Detection) is investigated in the presence of n-interfering signals whose random amplitudes are considered as Rician distributed. Numerical results are presented, indicating the effect of propagation impairments on channel capacity. The results are of importance for mobile networks and indoor wireless office communications.Electrical Engineering, Mathematics and Computer ScienceTelecommunicatie- en Verkeersbegeleidingssysteme
Unslotted Hybrid CDMA/ISMA Protocol for Indoor Wireless Computer Communications
No full textA hybrid Code Division Multiple Access / Inhibit Sense Multiple Access (CDMA/ISMA) protocol has been proposed as an effective multiple access scheme for Indoor Wireless Computer Communications. This new protocol combines the advantages of both CDMA and ISMA into one protocol. On the one hand the ISMA protocol introduces a limitation to the number of simultaneous accesses to the transmission channel. On the other hand the CDMA protocol introduces an improvement to the packet survival chance. It is shown that the performance of the hybrid protocol is indeed better than CDMA only. In addition, code sharing can be applied to reduce hardware cost. The slotted hybrid CDMA/ISMA protocol using the p-persistent ISMA scheme has already been analysed. In this report, we investigate the hybrid protocol using the unslotted non-persistent ISMA scheme. The analysis is done for a star-connected multiple access wireless computer network. The performance comparison between the slotted and unslotted hybrid CDMA/ISMA protocol is evaluated in terms of throughput and delay using computer simulation and mathematical analysis.Electrical Engineering, Mathematics and Computer ScienceTelecommunicatie- en Verkeersbegeleidingssysteme
Performance Analysis of Slotted ISMA Protocols for Mobile Communications on a Three Lane Motorway
No full textA slotted ISMA protocol has been proposed for using with the communication channel from vehicles to a base station near the motorway. In this report the performance of this channel using the proposed protocol is analysed. Three slotted ISMA protocols can be distinguished, namely: • p-persistent slotted ISMA; • 1-persistent slotted ISMA; • non-persistent slotted ISMA. The performance of the protocol has been measured in terms of the throughput and the packet delay of the communication channel. The system has been modelled by assuming a capture receiver at the base station. The vehicles are assumed to maintain constant velocities while moving in one direction inside a cell of 200 metres on a three-lane motorway. The distribution of the vehicle positions on the motorway has been considered. Also the influence of the packet length and collision detection ratio will be examined. Furthermore the integration of DECT with the designed system is investigated. The performance of the system has been investigated for three traffic types: light traffic, heavy traffic and queuing traffic.Applied SciencesElectrical EngineeringTelecommunications and Traffic-Control Systems Grou
Performance Analysis of a Hybrid ISMA/CDMA Protocol for Indoor Wireless Communication
No full textThe hostile transmission medium encountered in Indoor: Wireless Communications (IWC) requires the use of special communication protocols. In this report we investigate a combination of the Inhibit Sense Multiple Access (ISMA) and Code Division Multiple Access (CDMA) protocols. The ISMA protocol limits the number of simultaneous accesses to the transmission channel and the CDMA protocol improves the packet survival chance. With CDMA each bit is transmitted using several code bits, giving each signal has its own, easy to recognize, signature. Coding spreads the signal over a large transmission bandwidth, which makes it particularly resistant to fading and multipath propagation, two key factors which degrade network performance…Applied SciencesElectrical EngineeringTelecommunications and Traffic Control Systems Grou
Hybrid CDMA / ISMA Protocol in Rician Fading Channel in Indoor Wireles Data Communications
No full textThis thesis describes the performance analysis of a star-connected, indoor wireless computer data communication system using direct-sequence code division multiple access (DS-CDMA) and Hybrid CDMA / Inhibit Sense Multiple Access (ISMA) protocol. The channel performance is investigated in terms of bit error rate (BER) and the protocol performance is investigated in terms of traffic-throughput and throughput-delay characteristics. To enhance the performance, a diversity technique using Maximum Ratio Combining (MRC) is used. Comparison of the simulation results with the analytical results is also performed.Applied SciencesElectrical EngineeringTelecommunications and Traffic Control Systems Grou
A legal study on internet service provider: rights and liabilities for defamation via the internet / Nik Nurul Aishah Nik Rashid, Isma Nadia Ajis and Nor Adila Razak
No full textDefamation on the internet is not a new issue anywhere in the world. Rightfully, a person being defamed will take action against the defamer. However, the broadness of internet makes it hard to identify the real identity of the defamer which hard for the victim to bring an action against the defamer. The Internet Service Providers (ISPs) are sued instead. In Malaysia, defamation is governed by Defamation Act 1957. However this act is in comprehensive in dealing with the ISPs' rights and liabilities when compared to the laws of other countries. This project analyses the rights and liabilities of the ISPs in Malaysia specifically in defamation via the internet
Ekonomi politik komunikasi : sebuah realitas industri media di Indonesia
No full textBuku ini membahas tentang pemahaman yang komprehensif mengenai bagaimana relasi dalam politik komunikasi, yang berkelindan pada penggunaan sumber daya menghasilkan konten yang didistribusikan kepada masyarakat. Buku ini juga menjelaskan ekonomi politik dalam sudut pandang proksis. Aspek - aspek perkembanagn teknologi informasi dan komunikasi ini perlu dikaji lebih mendalam melalui sudut pandang ilmiah
Diversifikasi Dan Kolonialisasi Data pada Line Social Messaging
No full textPerkembangan internet tidak hanya menghilangkan batasan ruang dan waktu dalam mentransmisikan informasi, namun juga meningkatkan interaktivitas antar penggunanya. Kemudahan yang ditawarkan internet tersebut juga meningkatkan persaingan pasar di media digital. LINE sebagai aplikasi pengiriman pesan terus mengembangkan aplikasinya melalui diversifikasi berbagai fitur LINE agar dapat bertahan dalam persaingan pasar. Penelitian ini merupakan penelitian kualitatif deskriptif dengan paradigma kritis sebagai upaya untuk mengidentifikasi pergeseran fungsi aplikasi LINE sebagai bentuk praktik integrasi horizontal melalui diversifikasi fitur dan praktik kolonialisasi data pengguna yang dilakukan LINE melalui fitur-fiturnya. Pengumpulan data dilakukan dengan cara FGD, observasi, dan wawancara mendalam melalui teknik snowball sampling. Berdasarkan hasil temuan data, aplikasi LINE melakukan diversifikasi fitur untuk meningkatkan profit dan sebagai usaha untuk mempertahankan pasar ditengah perkembangan teknologi media digital. Usaha tersebut ditunjukkan dengan berbagai pengembangan fitur. Selain itu LINE juga melakukan agregasi data pengguna yang mengarah terjadinya praktik kolonialisasi data
Throughput analysis of some mobile packet radio protocols in Rician fading Channels
No full textThe throughput of packet radio channels is investigated theoretically using the interference model in Rician fading environment. Three types of packet protocols are considered, namely: i) slotted ALOHA, ii) unslotted nonpersistent ISMA, and iii) slotted nonpersistent ISMA. Numerical results are presented, indicating the effect of propagation impairments on channel capacity. The results are of importance for mobile data networks, wireless office communications and other packet systems with contention-limited performance.Electrical Engineering, Mathematics and Computer ScienceTelecommunicatie- en Verkeersbegeleidingssysteme
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