Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04H—BROADCAST COMMUNICATION
  • H04H20/00—Arrangements for broadcast or for distribution combined with broadcast
  • H04H20/12—Arrangements for observation, testing or troubleshooting

Definitions

• the invention relates to a method for searching usable transmission frequencies for TV and radio stations according to the preamble of claim 1.
• the procedures for national coordination and international coordination of radio stations are based on nationally and / or internationally agreed regulations of a technical nature, such as the International Telecommunication Union (ITU).
• ITU International Telecommunication Union
• the spectrum for broadcasting services in Central Europe is already very densely populated and therefore coverage up to the minimum useful field strength is usually not possible.
• the coverage area of a transmitter is predominantly limited or disrupted by the interference influences of other transmitters on the same or adjacent frequency. Based on this fact, planning additional frequencies is usually a redistribution of coverage. Since the interference range of a transmitter is greater than its coverage range, part of the supply potential of the frequency range is lost in this process. Scheduling additional transmitters is only possible if the associated impairment of existing, coordinated transmitters can be accepted.
• the invention is therefore based on the object of providing a method for searching usable transmission frequencies for TV and FM radio stations or the like, which theoretically determines all frequencies, for example in the FM band or a sub-range thereof, which could successfully pass through the coordination , whereby all effects, for example on the coordinated VHF transmitter network, are determined and the suitability of each frequency in a frequency grid in the respective frequency band or in a sub-range is to be examined according to the respectively specified criteria in order to obtain as a result all frequencies which correspond to the given conditions could be coordinated, so that after checking the frequencies determined, a clear decision is finally possible by the frequency planner.
• the method determines all effects on the coordinated VHF transmitter network or TV transmitter network and examines the suitability of each frequency according to predefined criteria, for example in a 100 kHz grid in the entire VHF band or in a sub-area. The result is all frequencies that could be coordinated according to the given conditions. At the same time, the usable field strength is determined and specified. For The frequency planner then has the task of finally checking the frequencies determined and deciding which one is used. The statement becomes more precise the more the effort for checking the coordination conditions is increased and the more precise the calculation methods are. Therefore, for example, in addition to the statistical propagation model, the more precise consideration of the topography (diffraction models) is also included.
• the present method is carried out with the aid of an information processing system, the following data and information processing modules being required:
• This database should be back-dated, i.e. it must be possible to simulate the transmitter network to a state at a previous time when a particular transmitter was scheduled,
• ITU International Telecommunication Union
• ITU International Telecommunication Union
• Test points that are to be examined on and within the respective supply contour of the transmitters concerned (fixed points, grid and the like),
• the flowchart according to FIG. 1 shows the basic method steps for the frequency search for TV and radio stations or the like.
• a compatibility check with the existing transmitter network is carried out.
• the calculation is carried out, for example, in 100 kHz steps (FM) in the selected frequency range, starting from the start frequency to the end frequency. So the parameters and the frequency range of the desired transmitter are defined.
• the usable field strength for the respective frequency at the location of the new transmitter is determined and saved. This value is used for Evaluation of the "potential quality of supply / possibility with this frequency".
• all transmitter locations in the same and neighboring channels e.g. FM range -400 to +400 kHz to the respective frequency
• the interference factor exceeds the specified limit, such as 34 dB.
• These stations are sorted according to the interference factor. Starting with the transmitter with the highest interference factor, the change in the usable field strength at the location, on the supply contour is calculated either from the existing file or in each case by calculation and at predetermined or determined (scheme / grid) test points. If the value for the permissible increase is exceeded, the interference factor is reduced until the permissible increase is observed.
• the reduction in the interference factor is saved as the required additional diagram indentation, marked with "criterion usable field strength". Since the change in the usable field strength is considered at the time of the respective transmitter being included in the plan (birth value), only backdating brings an exact result. However, you can use a threshold value for the current network. Subsequently, at predetermined reception locations, which can either be stored in a file or calculated according to a scheme / grid, in the coverage area of the transmitter concerned, it is examined whether there is a fall below the protective distance. According to today's rules (e.g. BAPT 313 RL 02), only those locations are permitted where the useful field strength is reached and which have not been affected so far, i.e.
• the protective distances of interfering signals and criteria for reflections are observed. If the safety distance is undershot, the interference factor is reduced until there is no longer a shortfall. The reduction in the interference factor is saved as the required additional diagram indentation, marked with "Criterion for individual interference analysis". These examinations can be carried out using a diffraction model or other known forecasting methods.
• the channels of all categories are sorted according to the value of the usable field strength at the "Location" test point. Once all channels have been calculated, the frequencies determined as suitable and the respective usable field strength with the respective possible transmission parameters and further calculation results are output.
• the results are then evaluated. Ideally, the frequency with the lowest usable field strength is suitable. First the category 1 result list is checked. If there are suggestions in this frequency, they will first be checked further for their suitability; if necessary, the characteristic features still have to be changed. If the output is positive, the frequency search is completed, which is represented by the "yes" in the flow diagram according to FIG. 1.
• a new calculation can be carried out until a suitable frequency is determined.
• test points The change in the usable field strength is calculated in test points.
• the FM range for example, an increase in the usable field strength by a maximum of 0.5 dB is permitted since the time the transmitter was included in the plan.
• This calculation rule requires a sender database that can be back-dated for comparison calculations. If this is not possible, you have to work with a lower threshold value (e.g. 0.1 or 0.2 dB) and check it later.
• a special test point is always the location; for this, the calculation is made without taking into account the directivity of the receiving antenna for stereo reception with FM, analog with TV. At this test point, a rough statement about the compatibility of the planning is already possible.
• the receiving antenna must be taken into account at all other test points.
• test points are only permitted on or within the interference contour, i.e. the useful field strength must be> the usable field strength.
• Interference contour in 10 "steps (azimuth, starting at north over east with directional reception antenna), interference contour at the point closest to the interferer (directional reception antenna), at the shortest distance (e.g. 100 m) behind the location of the user transmitter, with the receiving antenna aligned with the interfering transmitter, at the shortest distance (for example 100 m) behind the interferer, with the receiving antenna aligned with the useful transmitter if the interferer lies within the interference contour.
• test points can be defined within the interference contour according to the system to be specified.
• the number of specified test points determines the computing effort or the computer runtime.
• the interferer lies within the minimum field strength contour.
• further receiving locations can be defined inside and outside the minimum useful field strength contour.
• the number of specified receiving locations determines the computing effort or the computer runtime.
• An ideal variant both for test points and for receiving locations, is the specification of a grid that extends beyond the range of the minimum useful field strength according to the rules of the International Telecommunication Union (ITU) or according to the diffraction model.
• the density of the grid should be close to that Database resolution for topographical data can be adjusted.
• the change in the usable field strength is calculated and the compliance with the protective distance is checked (single-fault test).
• the compliance with the safety distance is checked according to the criteria described under the selection of the receiving locations.

Landscapes

• Engineering & Computer Science (AREA)
• Signal Processing (AREA)
• Monitoring And Testing Of Transmission In General (AREA)
• Mobile Radio Communication Systems (AREA)
• Transmitters (AREA)
• Radio Relay Systems (AREA)
• Channel Selection Circuits, Automatic Tuning Circuits (AREA)
• Testing, Inspecting, Measuring Of Stereoscopic Televisions And Televisions (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=7833797

Family Applications (1)

Country Status (7)

Cited By (1)

Citations (1)

Family Cites Families (1)

• 1997
  • 1997-06-27 DE DE19727301A patent/DE19727301C2/de not_active Expired - Fee Related
• 1998
  • 1998-05-16 WO PCT/EP1998/002895 patent/WO1999000920A1/de not_active Ceased
  • 1998-05-16 AT AT98928282T patent/ATE288157T1/de active
  • 1998-05-16 DE DE59812517T patent/DE59812517D1/de not_active Expired - Lifetime
  • 1998-05-16 EP EP98928282A patent/EP0992136B1/de not_active Expired - Lifetime
  • 1998-05-16 CZ CZ0474599A patent/CZ297539B6/cs not_active IP Right Cessation
  • 1998-05-16 PL PL98337525A patent/PL337525A1/xx unknown
  • 1998-05-16 HU HU0002200A patent/HUP0002200A3/hu unknown

Patent Citations (1)

Non-Patent Citations (2)

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