The carrier is a frequency carrier for wireless communication.

Digital data is transmitted over an RF carrier wave by modulating the carrier wave using on-off keying.

The wireless carrier (114) passes the signals on to the position server (120).

The invention relates to a method and an apparatus for selection of a radio carrier from a number of available radio carriers (12-14) in radio transmission systems.

A radio frequency modulator which is arranged to modulate a radio frequency carrier signal with the OFDM symbols for transmission.

After the 16 minutes long message sequence of the transmission is again the carrier at 82 Hz.

The terminal broadcasts an RF carrier field which is received by an aerial (12) in the token (10) and then converted into power and data.

The forward radio frequency carrier signal leakage can be suppressed simply and effectively by means of said system and method.

The mobile receiver (130) receives GPS signals, performs rudimentary signal processing and transmits the processed signals to the wireless carrier (114).

It has a splitter (44) dividing a radio frequency (RF) carrier signal into two signals between which a phase shifter (46) introduces a variable phase shift.

The apparatus comprises at least one mobile device (130), a reference network (115), a position server (120), a wireless carrier (114), and a location requester (122).

The main controller in the system of this invention, transmits a low-frequency radio wave, which is used as a carrier wave for digital signals, to the corresponding electronic label.

The WMC system transmits the various signal inputs using RF carriers, receives the transmitted signals, and converts the signals to the desired signaling scheme (standard) for forwarding to intended destinations.

The secondary station 4 further comprising signal quality determining means for determining at least an estimate of a signal quality of the frequency carrier presently tuned to.

The mobile device (130) is in communication with the wireless carrier (114) and receives global positioning system (GPS) signals from a plurality of satellites (102) in the GPS satellite constellation (101).