G. Keiser

Bio: G. Keiser is an academic researcher. The author has contributed to research in topics: Multi-mode optical fiber & Parallel optical interface. The author has an hindex of 1, co-authored 1 publications receiving 4 citations.

Fiber Optic Networks and Their Service Survival

Abstract: The objective of this study is to look at fiber optics networks in a predominately functional domain and to assess their potential survivability advantages from that point of view. As a consequence, service survivability is emphasized far more than physical survivability, although physical existence of facilities is a definite prerequisite for all telecommunications services. The need for a quantitative (or formal, or unique, or numerical) definition of the term "survivability" is addressed. The report proposes a partial solution to this problem. It introduces a network–related quantity, defined with the moments of the connectivity cross section histograms, that appears to possess many of the properties wanted for measuring and comparing survivability of different topologies. For lack of a better name, that quantity may be called the effective topological survivability index. The fiber advantage of large data throughput, typically in tens of Mb/s, must be exploited when connectivity or other network status is in doubt. This is part of the network reconstitution or restoration issue. Outlines of procedures, protocols, and formats are given to achieve comprehensive network–wide restoral for small but still realistic networks. The information fields of extensive reconstitution data arrays are possible and advisable. If transmitted, received, and stored rapidly, and not processed in a lengthy manner, these data arrays are shown to offer unprecedented restoral opportunities. Through locally or regionally focused restoration processes the methods appear practicable even for very large networks. The conclusion is that full–scale automation is essential. It should be distributed to all nodes of the network and its implementation should be with the very highest speed parallel processors. Any node that survives should be capable of both initiating and participating in the network restoration sessions. Thus, centralized hierarchical controls are to be avoided.

Transmission of a multiplexed eight channels subcarrier optically intensity modulated based on microcontroller.

Abstract: An optical fiber communication system for transmitting eight time division multiplexed analog signals each of bandwidth of 500 Hz was designed and implemented. The system utilizes the 8051 microcontroller as a parallel to serial converter in the transmitter side and parallel to serial converter in the receiver side in addition to the control process of the multiplexer and demultiplexer in both sides and for serial transmission via its RS232. The transmitted signal is subcarrier intensity modulated using the Amplitude Shift Keying (ASK) modulation technique with a carrier of 20 MHz. A laser diode of the type HFCT-5205 at 1300 nm wavelength was used as an optical carrier generator with an emitted optical power of -10 dBm, and a HFCT-S205 InGaAs/InP PIN Photodiode with responsivity of 0.36 A/W at the receiver side. A single mode fiber of (42 km) length was used as a tranasmission channel. This system can be utilized in the TDM fiber telephone lines often operating at higher rates such as T3 (44.7 Mbps), T3C (91 Mbps) and above. ق ي قدلا رطي سملا ىلع دىتسم يوواثلا لقاىلل ةدشلا هي مضت ةقي رطب ةجزتمم ت اوىق نامث لاسرإ

An Experimental Fibre-Optic Digital Video Link

Abstract: The developments in the fields of micro-electronics and fibre optics have made practical the transmission of broadband digital signals carrying large number of voice, video and data channels, over very long as well as short distances. The digital video signals require large bandwidths which arc not normally available on conventional copper cables. The optical fibres are finding increasing applications in digital video transmission because of their large information carrying capacity. Design considerations of an experimental fibre optic link for transmission of digital TV signals at a rate of 10 Mbps are discussed in this paper. The fibre-optic link, designed and implemented in our laboratory, consists of analog-to-digtal converter for TV signals, driver, amplifier and first generation light emitting diode, photo-detector and step index fibre. The analog TV signals are converted into digital form using delta modulation techniques developed in our laboratory.

Fibre Optic Bus Network For Voice And Data Transmission In A Ship

Abstract: A versatile communication system in a ship with 120 stations, each having voice and data transmission is envisaged. The proposed fibre optic network has a bus topology ideally suited for distribution in ship-like environment. Use has been made of standard ETHERNET chip sets manufactured by INTEL. This makes the stations compact, easier to maintain and inexpensive. The ETHERNET proto-col is primarily designed for packet data transmission. The collision detection and backoff protocol makes the packet transmission probabilistic and is therefore not suitable for voice transmission. This problem is overcome in the present design by a scheme where the required number of voice slots are dynamically allocated. That is, having established a connection for voice communication between stations, fixed slots are assigned for voice transmission and reception. The data transmission continues to use CSMA/CD Protocol. A simple hardware addition to the ETHERNET chip set makes the scheme workable. Drops in the fiber optic bus network is through passive star couplers. Four to eight star couplers are used in the present scheme with repeaters between adjacent star couplers. The repeaters will not be usual repeaters, as ordinary repeaters would cause loops to be formed between adjacent stars, thereby causing data to recirculate. This recirculation is avoided by making the repeater intelligent and also performing the task of detecting collisions between signals originating from stations connected to different star couplers.