System and method for indoors altitude determination

An altitude determining circuitry for use in a user equipment of a wireless communication network, the altitude determining circuitry comprising:

• a receiver to receive at least one pressure parameter representative of a plurality of indoors pressure measurements from a respective plurality of indoors pressure measurement units located inside a building at corresponding measurement-unit altitudes;
• and
• processing circuitry to receive from a pressure sensor in the user equipment a local pressure measurement at the user equipment and to determine an indoors altitude of the user equipment using the at least one pressure parameter and the local pressure, wherein the plurality of indoors pressure measurements comprise at least two indoors pressure measurements corresponding respectively to at least two different measurement-unit altitudes.

An indoors pressure measurement unit for performing a pressure measurement to enable calculation of an indoors altitude by a user equipment of a wireless communications network, the indoors pressure measurement unit comprising:

• a pressure sensor for performing a pressure measurement corresponding to an altitude at which the indoors pressure measurement unit is located;
• a transmitter to transmit a pressure parameter depending upon the pressure measurement to one of the user equipment or a further indoors pressure measurement unit, the transmitted pressure parameter enabling determination of an indoors location of the user equipment using the transmitted pressure parameter and at least a further pressure measurement performed locally at the user equipment.