Method for selecting an antenna

A system comprising a first device and at least one second device, each second device being mobile, the system forming a communication network in which the first device communicates with each second device using a medium-access technique of a time division multiple access type in which each communication takes place in frames, each frame being divided into a plurality of timeslots comprising a first slot enabling the first device to transmit a first signal designating a second device and enabling each second device to synchronize timewise on a time reference of the first device, and a second slot enabling the second device designated by the first signal to transmit a second signal in response to the first signal in order to acknowledge its presence in the system, at least the first device comprising a plurality of antennas each covering a predefined sector in a vicinity of said plurality, wherein:

• the frames used in said system are organized in a succession of groups of consecutive frames, each group of frames being organized in a group structure associating each frame with a pair formed by an antenna of the first device and of each second device, each possible pair being associated with a different frame in the group of frames according to a position of said frame in said group, information representing the structure of the group being shared between the first and each second device;
• and each device in the system comprising a plurality of antennas comprises:
• obtaining means for obtaining, from the first or second signal transmitted in each frame in the group of frames, information representing a quality of communication between an antenna of said device and the antenna of the first or of at least one second device;
• and
• selection means for selecting, from all the information representing the quality of communication obtained, the antenna in its plurality of antennas offering a highest quality of communication with the antenna of the first or of at least one second device.

A ground control station included in a system comprising at least one second mobile device, the system forming a communication network in which the ground control station communicates with each second device using a medium-access technique of a time division multiple access type in which each communication takes place in frames, each frame being divided into a plurality of timeslots comprising a first slot enabling the ground control station to transmit a first signal designating a second device enabling each second device to synchronize timewise on a time reference of the ground control station, and a second slot enabling the second device designated in the first signal to transmit a second signal in response to the first signal, the ground control station comprising a plurality of antennas each covering a predefined sector in a vicinity of said plurality, wherein:

• the frames used in said system are organized in a succession of groups of consecutive frames, each group of frames being organized in a group structure associating each frame with a pair formed by an antenna of the ground control station and of each second device, each possible pair being associated with a different frame in the group of frames according to a position of said frame in said group, information representing the structure of the group being shared between the ground control station and each second device;
• and wherein the ground control station comprises:
• obtaining means for obtaining, from the second signal transmitted in each frame in the group of frames, information representing a quality of communication between the antenna of the ground control station and the antenna of at least one second device to which said frame relates;
• and
• selection means for selecting, for each second device, from each item of information representing the quality of communication between the antenna of the ground control station and the antenna of said second device, the antenna in its plurality of antennas offering a highest quality of communication between the ground control station and said second device.

A pilotless mobile device included in a system comprising a first device and at least one pilotless mobile device, the system forming a communication network in which the first device communicates with each pilotless mobile device using a medium-access technique of a time division multiple access type in which each communication takes place in frames, each frame being divided into a plurality of timeslots comprising a first slot enabling the first device to transmit a first signal designating the pilotless mobile device and enabling each pilotless mobile device to synchronize timewise on a time reference of the first device, and a second slot enabling the pilotless mobile device designated by the first signal to transmit a second signal in response to the first signal, the first device and each pilotless mobile device each comprising a plurality of antennas each covering a predefined sector in a vicinity of said plurality, wherein:

• the frames used in said system are organized in a succession of groups of consecutive frames, each group of frames being organized in a group structure associating each frame with a pair formed by an antenna of the first device and the pilotless mobile device, each possible pair being associated with a different frame in the group of frames according to a position of said frame in said group, information representing the group structure being shared between the first device and each pilotless mobile device;
• and wherein the pilotless mobile device comprises:
• obtaining means for obtaining, from the first signal transmitted in each frame in the group of frames, information representing a quality of communication between the antenna of the first device and the antenna of said pilotless mobile device;
• and
• selection means for selecting, from each item of information representing the quality of communication between the antenna of the first device and the antenna of said pilotless mobile device, the antenna in its plurality of antennas offering a highest quality of communication between the first device and said pilotless mobile device.