Wireless assisted altitude measurement

A communication device comprising:

• a pressure sensor for measuring local barometric pressure;
• a transceiver for communicating with another communication device, wherein the transceiver receives barometric pressure measurements from the other communication device;
• and
• a processor for determining an altitude of the other communication device based on the received barometric pressure measurements and local barometric pressure measurements by the pressure sensor, wherein the pressure sensor is at a known elevation;
• wherein the communication device is a mobile-telephone, a base station belonging to a wireless communication network or a position determination entity.

A communication device comprising:

• a pressure sensor for measuring local barometric pressure;
• and
• a transceiver for communicating with another communication device, wherein the transceiver transmits local barometric pressure measured by the pressure sensor to the other communication device, the other communication device being operable to calibrate the transmitted local barometric pressure measurements using barometric calibration information based on atmospheric pressure measurements at a known elevation;
• wherein the communication device is a mobile-telephone, a base station belonging to a wireless communication network or a position determination entity.

A method of determining an altitude position of a communication device comprising the steps of:

• measuring local barometric pressure at the communication device;
• receiving barometric calibration information from another communication device, the received barometric calibration information barometric being based on atmospheric pressure measurements at a known elevation;
• and
• determining the altitude position of the communication device using the measured local barometric pressure and the received barometric calibration information;
• wherein the communication device is a mobile-telephone.