Point to multipoint radio access system

Claim 1

A method of allocating radio link characteristics in a point to multipoint radio access system, the point to multipoint radio access system comprising a number of base stations including a selected base station connected by a plurality of radio links to a corresponding plurality of subscriber terminals located within respective coverage areas of the selected base station, at least some of the plurality of radio links being within a same frequency band, the method comprising: for the selected base station, selecting a base station power density which, for each of a plurality of modulation types, is constant for all bitrates; for each of the plurality of subscriber terminals located within the coverage area of the selected base station, selecting a terminal power density which, for each of the plurality of modulation types, is constant for all bitrates; determining a maximum range for each of the plurality of modulation types; for each of the plurality of subscriber terminals, allocating a modulation type to the corresponding radio link dependent upon range from the selected base station; determining, for each of the plurality of subscriber terminals, whether at the subscriber terminal there is an acceptable signal quality and, if not, allocating a next lower modulation type to the radio link corresponding to the subscriber terminal which does not have the acceptable signal quality; and determining at the selected base station whether there is an acceptable signal quality with respect to each of the plurality of subscriber terminals and, if not, allocating a next lower modulation type to the radio link corresponding to the subscriber terminal with respect to which there is not the acceptable signal quality.

Claim 2

A method of allocating radio link characteristics in a point to multipoint radio access system, the point to multipoint radio access system comprising a number of base stations including a selected base station connected by a plurality of radio links to a corresponding plurality of subscriber terminals located within respective coverage areas of the selected base station, at least some of the plurality of radio links being within a same frequency band, the method comprising: for the selected base station, selecting a base station power density which, for each of a plurality of modulation types, is constant for all bitrates; for each of the plurality of subscriber terminals located within the coverage area of the selected base station, selecting a terminal power density which, for each of the plurality of modulation types, is constant for all bitrates; determining a maximum range for each of the plurality of modulation types; for each of the plurality of subscriber terminals, allocating a modulation type to the corresponding radio link dependent upon range from the selected base station; determining, for each of the plurality of subscriber terminals, whether at the subscriber terminal there is an acceptable signal quality and, if not, allocating a next lower modulation type to the radio link corresponding to the subscriber terminal which does not have the acceptable signal quality; and determining at the selected base station whether there is an acceptable signal quality with respect to each of the plurality of subscriber terminals and, if not, allocating a next lower modulation type to the radio link corresponding to the subscriber terminal with respect to which there is not the acceptable signal quality.