Abstract: The cellular system for transmitting information by radio between an infrastructure and mobiles constrained to travel on a determined path comprises stationary transceiver stations and at least one transceiver carried by each mobile, which transceivers are controlled in such a manner that, while a mobile is in a given cell, exchanges between the mobile and the transceivers allocated to the cell take place on two different frequencies in alternation during two successive radio cycles.

Abstract: The cellular system for transmitting information by radio between an infrastructure and mobiles constrained to travel on a determined path comprises stationary transceiver stations and at least one transceiver carried by each mobile, which transceivers are controlled in such a manner that, while a mobile is in a given cell, exchanges between the mobile and the transceivers allocated to the cell take place on two different frequencies in alternation during two successive radio cycles.

Abstract: A motion measurement device, more particularly designed for measurement of a rotation of a body around an axis. This device comprises a coded wheel drivably connected to said body for rotation and comprising a plurality of holes regularly distributed around said axis. Said holes are binary digits and for one digit is constituted by a simple hole passing through the wheel and, for the other, an open hole connected to the nearest edge of said wheel by a narrow slit. A sensor placed on the path of the holes and comprising two coils facing one another allows determination of the distance travelled by the moving body connected to said coded wheel. The speed and acceleration of the moving body can also be determined.