Calculator functions

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Calculator functions in WRAP

• Different calculation functions in different dialogues

• Geographical calculations• General radio calculations• Minimum separation calculations• Transmitter, receiver and antenna

calculations

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Geographical calculations

• Conversion of co-ordinates between geographical datums

• Distance and bearing between two points• Free space loss between two points• Roughness

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Geographical calculations

• Roughness is defined as the inter-decile height

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Map Viewer

• Area of a circle or polygon• Length and bearing of line• Distance and bearing between points

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Radio calculations

• Unit conversion, Basic radio propagation, Traffic and Cable calculator functions

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User defined table

Radio calculations, cont’d

• Effective Earth radius factor according to COST 210

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1 1.5 2 2.5 3 3.5 4 4.5 510

20

30

40

50

60

70

80

90

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Radio calculations, cont’d

• Traffic capacity calculations according to the Erlang B and Erlang C formulas

• Grade of Service, No of channels, calls per hour or holding time is calculated

• For Erlang C waiting time and probability of delay is also calculated

• Cable attenuation for different cable lengths and frequencies

• Cable data in WRAPdB

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Minimum separation calculations

• Calculates minimum frequency separation between transmitting and receiving station

• Transmitter spectrum and receiver selectivity are taken into account

• Any propagation model can be used

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Minimum separation calculations

• Calculates minimum distance between transmitting and receiving station

• Transmitter spectrum and receiver selectivity are taken into account

• Only terrain independent propagation models

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Minimum separation calculations

• Iterates until the following expression is fulfilled

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dBcalculatedIM

requiredI

Sysensitivit

SdB 11

Transmitter calculations

• Occupied bandwidth, (Power above and below frequency limits equal to /2 of total power)

• Transmitted power (Power within frequency limits)

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Transmitter calculations

• Generation of modulation spectrum– AM and FM assumed to be Gaussian – M-ary PSK and M-ary QAM with raised cosine

roll-off filter– MSK– GMSK

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Receiver calculations

• Intercept point • Intermodulation level• Noise and sensitivity

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Antenna calculations

• Conversion between antenna gain, lobe width, diameter and frequency

• Conversion between the units dBi, dBd and dBv

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Satellite calculations

• Azimuth, elevation and distance between earth station and satellite

• Satellite visibility check• Visibility of the geostationary orbit• Antenna noise (according to ITU-R

SA.1017)

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