The SPAN cookbook: A practical guide to accessing SPAN

This is a manual for remote users who wish to send electronic mail messages from the Space Physics Analysis Network (SPAN) to scientific colleagues on other computer networks and vice versa. In several instances more than one gateway has been included for the same network. Users are provided with an introduction to each network listed with helpful details about accessing the system and mail syntax examples. Also included is information on file transfers, remote logins, and help telephone numbers

A communications model for an ISAS to NASA span link

The authors propose that an initial computer-to-computer communication link use the public packet switched networks (PPSN) Venus-P in Japan and TELENET in the U.S. When the traffic warrants it, this link would then be upgraded to a dedicated leased line that directly connects into the Space Physics Analysis Network (SPAN). The proposed system of hardware and software will easily support migration to such a dedicated link. It therefore provides a cost effective approach to the network problem. Once a dedicated line becomes operation it is suggested that the public networks link and continue to coexist, providing a backup capability

Providing telecommunication to the tea plantations in Bangladesh

Analyzing all the existing telecommunication technologies in Bangladesh, discussing their merits and demerits, and choosing the most viable option in order to provide a network system to the tea planters for facilitating updating of necessary information of the tea estates to the head offices and vice versa

On a Packet-Wise Data Transfer Monitoring System

This work tends to propose a billing system that is measured by the quality of bits/bytes transfer. In order to determine the amount of network resources to be reserved, traffic and performance descriptors must be defined. Allocated resources are used only when customers send or receive traffic, whereas when customers are inactive, resources may remain unused. Network administrators clearly prefer to charge users in proportion to the reserved resources, that is to say in proportion to the potential use of the service. In packet-wise billing system, subscribers are bill based on the actual amount of data transferred as in terms of byte. This research was carried out at unical e-library because of their facility, the researcher designed a server which serves as the billing system, in the server which is ubuntu driven, the researcher install the radius server, PHP Admin and mysql. The reason being that the radius server will do the authentication, accounting and access control, then the researcher use the packet sniffer to retrieve packet from the network using mikrotik router to connect the server and the client computer. It was discovered that when a user tries to connect to the server, it will be requested to enter a username and password that will give him/her access to the server. With this a capture will display showing that the user was successfully logged in with it bandwidth detail on it instead of time. So with this, a user can freely enjoy the service of the internet Keywords: reserved packets,, bandwidth, packet-wise billing system, processor clock timer,   weighted fair queuing, Flat rate model

Data Communication in Bulgaria - The Telecommunication Infrastructure and Relevant Administrative Procedures

In a small country with an open economy such as Bulgaria the potential role of transborder data flows is enormous. In what follows the present and future data communication infrastructure of Bulgaria will be described and the relevant administrative procedures outlined. Special emphasis will be given to the present transborder data flow applications of the country, which are characterized, in addition to the "classical" flow of data for civil aviation, information, news agencies' data, and meteorological data networks, by an emerging data base production and service industry

Security Review and Study of DoS Attacks on LTE Mobile Network

The main objective of 3GPP long term evolution (LTE) is to provide a secure communication, high data rate and better communication for 4G users. LTE support all IP based data and voice with speed in order of hundreds of mega-bytes per second. Increase speed in accessing internet. Network to be attached by hackers using some attacks like spyware ,malware ,Denial-of-Service (DoS) and Distributed Denial-of-Service(DDoS) .This paper associated with security problem in LTE network and brief summary of DoS attack , DDoS attack and security vulnerabilities in LTE networks

An Investigation into Cognitive Radio System Performance

The objective of this thesis is to explore cognitive radio performance through an in-depth literature review and an implementation of a software-defined radio prototyping system. Specifically, this thesis investigates the spectrum-sensing aspect of cognitive radio by comparing two spectrum-sensing methods. It was found in the literature review that a system utilizing matched filter detection would provide higher probability of detection in low signal-to-noise ratio environments when compared to a system utilizing energy detection. These spectrum sensing methods were thus implemented and compared in the cognitive radio systems presented in this thesis. Additionally, experiments were conducted to determine the most efficient intervals for the spectrum sensing and cycle interval periods. Therefore, system performance was measured on the basis of probability of successful primary user signal detection and maximum throughput capabilities, quantified by bit error rate. It was found that a cognitive radio system based on matched filter detection was more robust, given that the transmitted signal of interest was previously known. However, compared to a system based on energy detection, the implementation of the matched filter required more complex algorithms and computational power. These results are consistent with the findings in the literature review

A Field study to determine the feasibility of establishing remote data transmission of advertising for a local newspaper

In recent years, local newspaper\u27s advertising revenues have been seriously eroded by the presence of competing electronic media. Technological innovation in cable television (CATV), interactive multimedia, broadcast television and Compact Disc-Read-Only Memory (CD-ROM) have proven to be a double-edge sword for local newspaper advertising revenues. On one hand, these technologies provide lower cost, high quality advertisement which target larger, more diverse audiences. On the other hand, the same technological innovations (high speed digital transmission, high quality input and output devices, and the widespread use of portable computing) have created a means for local newspapers to protect their advertising base and realize increased customer satisfaction through on-site interaction in early phases of ad development through remote data transmission. In this context remote data transmission involves the use of high speed transmission facilities capable of transmitting data of rates in excess of 56,000 bits per second. Adobe Acrobat 2.0 was used as a means of maintaining the integrity of the advertisement\u27s elements as part of the transmission process. The author conducted a field experiment to determine the feasibility of remote data transmission of advertising between Advertising Services at Syracuse Newspapers in Syracuse, New York and a well known retailer - Kaufmann\u27s Department Stores. A Kaufmann\u27s ad was converted from PostScript to a Portable Document File (PDF) using Adobe Acrobat 2.0 Pro Distiller. The ad was transmitted to Advertising Services using switched 56 telecommunication line and a modem. Advertising Services transferred the ad into Adobe Acrobat 2.0. The ad was calibrated using -5 Calibration Curve in the AdSEND Calibration based on GammaTrol measurements, press data and evaluations of the press proofs Based on the evaluation of the press proofs, -5 Calibration Curve was the best calibration for Goss press and newsprint paper. The shadow was set at 95%, midtone at 45% and highlight at 0% in AdSEND Calibration. The shadow measured 78%, midtone at 58% and highlight at 0% on the press proof. The shadow measured 65%, midtone at 43% and highlight at 4% on the actual newspaper ad. The author concluded remote data transmission was feasible using a switched 56 telecommunication line, a digital modem and Adobe Acrobat 2.0 for electronic delivery of advertising for newspapers

X.25 traffic generator

Due to the lower cost and error free data transmission capabilities offered by packet switching, numerous countries have installed national packet switched networks. The South African packet network, SAPONET-P, became operational in 1982 and has been growing rapidly, creating a need for network test equipment. This thesis describes the design of a high speed traffic generator which can be used to test and monitor the throughput capabilities of equipment or part of the network as a whole. To meet the main requirement of the traffic generator, that it should support a number of high speed X.25 lines, a multiprocessor architecture was chosen to cope with the high data throughput. An IBM PC was used as the base system, with several specially designed X.25 cards being installed in its expansion slots. The major part of the work done was on the design and development of the X.25 cards, each of which provides two high speed (64 Kbps) X.25 links. In order to achieve this throughput, the card uses three processors coupled on a local bus to a 256K multi-port memory. Two WD25ll processors implement the link level of the X.25 packet switching protocol (LAPB), with the required software being micro-encoded on the chip. An 8088 processor, the same as is used in the PC, implements the packet level, the traffic generator and overall control of the card. Extensive use was made of programmable array logic (PAL) devices to implement the system logic required. All programs for the traffic generator are written in the modern and powerful c language which is ideally suited to the application. The software was written in a modular fashion with the various modules being linked together by means of a set of common data structures. Use was made of packet buffers and job queueing to allow the traffic generator to cope with very high peak data rates. As well as programs for the X.25 cards, a monitor program runs on the PC and allows the· user to view statistics screens and modify the traffic generator configuration. While primarily designed for the,traffic generator application, the X.25 card may also be configured for a variety of other networking applications. By substituting a local area network (LAN) processor for the X.25 one, the card can be used as a low cost network card or as a network file server. The card can also be configured to provide a low cost means of connecting a PC based workstation to the packet switching network. As all programs are downloaded onto the cards from the PC, it is relatively easy to modify or upgrade the software. Thus while meeting the original project requirements, the traffic generator design has a flexible and expandible nature