Top 10 Interview Tips To Be A Good Student

10 tips to find your true purpose in life 5 mistakes to open and close presentations

One of the main conditions of improvement and strengthening of material base of society is existence of branched, technically perfect communication. In our country the Uniform automated EASS communication network is for this purpose created. In development of EASS means of a radio communication have an important role: radio relay, tropospheric and satellite.

First, it researches and development of the new canals of information transfer founded on the new physical principles: use of effect of distant tropospheric distribution, development of new wave bands, including optical, development and fiber-optical light guides, development and deployment of satellites of Earth – carriers of the relaying equipment.

Use of powerful radio transmitters, sensitive radio receivers in a combination to the difficult scheme of the carried reception, in general, increases the cost of the equipment of separate stations. However the total cost of tropospheric RRLS often even is lower in comparison with RRLS of direct visibility thanks to reduction at 5-10 than times of number of intermediate stations.

Limitation of distance of direct visibility should not be considered as especially negative factor. Due to impossibility of free distribution of radio waves on long distances mutual hindrances between RRSP in one country or the different countries are eliminated.

Communication systems on decameter waves use most often in broadcasting, however, despite development of other means, they did not lose the value and for communication, especially where powerful bunches of channels are not required and it is economically expedient to have all the telephone or telecode channel. The most difficult for the researcher at creation of concrete optimum system of transfer is the choice of criteria as have to be estimated not only all most essential parameters including cost, but also the social and economic criterion which is difficult described mathematically. And the decision giving the best effect on one of criteria most often do not provide it on another. Moreover, in the course of development of the system of transfer (lasting sometimes more. 5 years) the chosen criteria can undergo such changes that the system, optimum at the time of the beginning of development, becomes non-optimal (by the same criteria!) at the end.

economically and technically expedient distribution of the difficulties arising at implementation of so high requirements between the terminal channel equipment (the difficult coding devices) and the equipment of a path of transfer (send-receive antennas, the equipment etc.);

Secondly, improvement of the equipment providing transfer and information processing: use of new products of electronic industry – the integrated schemes, transistors capable to function at more and more high frequencies, in particular, using new physical processes; creation on the basis of microprocessors of the terminal equipment for reception and processing of discrete information which by dynamic programming of the COMPUTER can provide, for example, change of speed or even a way of transfer according to change of conditions in a communication channel.

finding of such methods of transfer and coding which in the conditions of influence of additive and multiplicative hindrances would approach the speed of information transfer and its accuracy to the ratios following from the known theorem of Shannon (at preservation of reasonable complexity of the equipment).

The main criterion of a choice of system of transfer is the economic efficiency determined by capital expenditure and operational costs. At a final choice consider also such indicators as reliability of information transfer on channels, duration of action and speed of introduction of system, labor productivity increase, an electric power expense (especially in the absence of the centralized power supply) etc. So, for determination of economic efficiency of costs of construction and operation of RRSP it is expedient to compare to the corresponding expenses when using symmetric coaxial cables. For multichannel systems it is necessary to consider also: as these expenses decrease with increase in number of channels.