Technology - Tele informatics
Stáhnout kompletní materiál zdarma (28,5 kB)
Níže je uveden pouze náhled materiálu. Kliknutím na tlačítko 'Stáhnout soubor' stáhnete kompletní formátovaný materiál ve formátu DOC.
12. Teleinformatics Definition of Basic Concepts The type of transmitted information determines the basic characteristic of transmission, which is divided into the following categories: Data transmission – Systems have different requirements on data interfaces and have, therefore, also different requirements on transmission parameters. Image transmission – Systems have high requirements on a quality physical layer. Single applications in teleinformatics have different requirements on dynamics of processing and can, therefore, be divided into the following groups: Static processing of information – This expresses that information is not used for on-line applications but is only used for a long-term description of the examined system. These applications will not have any requirement on timely delivery of information into the center – therefore, common telecommunication tools can be used (SMS, messages, Internet). Dynamics processing of information – This means that information is used on on-line equipment. High level of availability of the telecommunication environment has to be secured for transmission of this information (in both directions). Therefore, construction of special city networks with high availability can be seen in Europe that will secure a telecommunication environment with a sufficient level of quality (they secure an integrated transmission of information). Single nodes of these networks are placed as close as possible to given applications. Creation of telecommunication environment has to guarantee requirements of users on availability of information and its safe and reliable transmission from the point of collection to the point of processing. These concepts can be defined: Transmission availability – Expresses time, during which it is permissible that the teleinformatics service is out of operation. The general availability can be expressed as a sum of set of availability of single parts of the teleinformatics application. For example, availability of transmission systems (redundancy of channels), availability of service (rapidity of repairs) and availability of the physical layer (suitable systems architecture) can be monitored for a telecommunication environment. Transmission security– Expresses level of security of transmitted information. This can be solved either by means of interface software for single applications or by constructing an own permanent telecommunication network or, in case of radio tools by means of a security protocol of the transmitted message. Transmission reliability – Expresses reliability of single parts of the transmission chain and is in direct relation with the availability concept. The transmission reliability includes reliability of single devices, reliability of the physical layer, quality of execution of technologies but also resistance of selected technical tools against disturbance (EMC, EMS). Basics concepts for creation of architecture of the teleinformatics system are: Integrated telecommunication transmission – Voice, image and data are transmitted together within a single telecommunication environment (ATM systems). The solution affects input investment costs and subsequent operation costs. Transit level of telecommunication environment –Expresses interconnection of single nodes (ATM). It is characterised by high transmission rates. The node interconnection architecture can lead to various availability values, such as: Ring architecture – has high availability of transmission Grid architecture – has high availability of transmission Star architecture– has low availability of transmission Access network – has a character of a local network but with respect to the character of transmission of information, it is necessary to secure an integrated transmission as close as possible to the particular application. Therefore, also access networks have to comply with higher requirements on transmission availability. Local access network – Requires transmission of information between the access network node and single information sources (sensors). From the point of data carrier, the network can consist of various types of telecommunication environment. Permanent networks – Consist of metallic or optical cable networks. Radio networks – Networks in which air is the transmission media. There are various types of analogue and digital networks (GSM, TETRA, microwave links, etc.). These networks will be used always where there is not permanent network available (namely in access networks districts). Reliability of radio transmission has only a limited level. Satellite transmission – Satellite channels are used for transmission of information. They are used always where there is no permanent network available. The concept of transmission reliability in satellite communication is somewhat complicated. According to the type of transmitted information, the transmission can be divided in to the following types: Transmission of static information – This requires no special telecommunication environment to be created. The transmission can be realized in any telecommunication environment, where the main decisive criterion will be price for the transmitted information. However, creation of the telecommunication environment must correspond not only with basic characteristics, but it also has to meet user’s requirements on availability, security and reliability of transmission. Transmission of dynamic information – this requires a special telecommunication environment to be created, namely in the access section. If applications will have a sufficient level of security, the transit network levels of various operators can be utilized, because they are generally constructed to provide sufficient availability and reliability of transmission. The network architecture will be specified by means of analytical and optimization methods so as to meet the requirement on transmission parameters of single applications. From the point of view of information transmis