Frequency Assignment 1 WRAP 0863F

Frequency Assignment WRAP efficiently supports assignment of frequencies and polarisations to stations and networks 2 WRAP 0863F All services Manual assignment Automatic assignment Simplex Duplex Consider or exclude existing assignments Ordinary or orthogonal polarisation

Assignment margin 3 WRAP 0863F

Links –Both the stations forming the link are tested for received signal-to-interference received signal transmitted interference Digital links –The expressions are modified according to S/I => max (T/I) S=> max (T) 4 WRAP 0863F

Area coverage For area coverage services 8 interference cases are tested: – Base 1 transmitter to base 2 mobile – Base 2 mobile to base 1 receiver – Base 2 transmitter to base 1 mobile – Base 1 mobile to base 2 receiver – Base 1 transmitter to base 2 receiver – Base 2 transmitter to base 1 receiver – Base 1 mobile to base 2 mobile – Base 2 mobile to base 1 mobile 5 WRAP 0863F

Area coverage 6 WRAP 0863F Area coverage services Base 1 Base 2 Mobile 1Mobile 2 RX level = Maximum (Sensitivity, Level at service area limit)

Automatic assignment Genetic algorithm Optimises the assignment based on –Minimum bandwidth: Smallest separation between highest and lowest frequency –Few frequencies: Minimum number of frequencies in the assignment –Interference: Minimum interference –Prioritised interference: Minimum interference on prioritised frequencies –Collocation interference: Minimum interference due to harmonics, intermodulation etc The different criteria are weighted This method gives a random assignment. 7 WRAP 0863F

Automatic assignment Sequential algorithm Sort stations: –Smallest last –Generalised smallest last –Random Assignment: –Sequential as priority list –Station with smallest number of available frequencies Assign frequencies: –First acceptable frequency from either band edge –First acceptable that has been assigned to most stations This method gives a deterministic assignment. 8 WRAP 0863F

Automatic assignment settings 9 WRAP 0863F Sequential methodGenetic method

Manual assignment 10 WRAP 0863F The negative of the assignment margin is presented in a graphical display. –Red: Assignment margin negative, i.e. the calculated signal-to-interference ratio is too small, or the wanted signal is too small or the station interferes with another station –Blue: Already used by the station to be assigned –Yellow: Free to assign

Network assignment 11 WRAP 0863F All stations in networks are assumed to communicate with each other Stations within a network do not interfere with each other (only one transmission at a time) Display of margin diagram either –Network orientated: Situation for the worst link in the network –Station orientated: Situation for each marked station. Main frequency and Reserve frequency can be assigned. The minimum separation between main/reserve can be defined. Genetic algorithm with minimum interference strategy, or the sequential algorithm can be used

Polarisation assignment 12 WRAP 0863F Wanted and interfering signal levels are calculated both for the ordinary and the orthogonal polarisation Cross-polarisation discrimination of antennas and propagation medium are considered Priorities: –First: Attempt to assign orthogonal polarisation on same frequency –Second: Attempt assign same polarisation on adjacent frequency –Third: Attempt to assign orthogonal polarisation on adjacent frequency. Polarisation properties of selected allotment are considered

Frequency allotment 13 WRAP 0863F Frequencies to be used by the assignment tool are picked from a frequency allotment (channelling plan) The allotment is defined by –Frequencies in the list –Duplex distance (if applicable) –Polarisation of frequencies Allotments are prepared in the Allotment tool.