| 主权项 |
1. A mobile communication and localization device configured for cooperating with a plurality of mobile network devices, the device comprising:
a processing unit; a data structure adapted to contain a plurality of entries, each entry containing information about a mobile network device belonging to said plurality of mobile network devices and a corresponding time stamp; means for sending data packets at successive instants of transmission to the plurality of mobile network devices, each data packet containing position data indicating positions of said mobile network devices; means for receiving data packets sent by said mobile network devices belonging to said plurality of mobile network devices, wherein information in the received data packet is incorporated into the entries in the data structure; means for managing the information contained in said data structure with a local clock, and managing the information contained in each said data packet with a time interval elapsed between the time instant represented by the time stamp associated with a pertaining piece of information, as stored in said data structure of said sending mobile network device, and the instant of transmission of said data packet, according to the local clock of said sending mobile network device; means for determining, based on said position data contained in said data packets, the relative positions of said mobile network devices and further wherein said data packets comprise indications of an alarm status of at least one other mobile network device belonging to the plurality of mobile network devices; and means for signaling an alarm status, wherein said processing unit comprises means for calculating estimated distances from said mobile network devices, said estimated distances being calculated at successive calculation instants, wherein said data structure is configured in a manner such that said information about a corresponding mobile network device contained in each entry comprises:
the estimated distance from said mobile network device, the time stamp associated thereto indicating the instant of reception of the data packet containing the power data used for calculating said estimated distance;a shortest path length, in the case of a first mobile network device belonging to a succession of mobile network devices and indirectly reachable through said succession, wherein the time stamp associated to said information indicating an instant of generation of a data packet by said first mobile network device wherein said means for determining said relative position of said mobile network devices comprise:
means for determining the instant of reception of each data packet;means for calculating, for each mobile network device identified by a position data contained in said data packet, a time stamp equal to the difference between the instant of reception and the time stamp associated to said position data;means for verifying if said data structure comprises an entry pertaining to said identified mobile network device;means for generating a new entry, which are activated in the event that there is no entry for said identified mobile network device, and which associate the shortest path length increased by one unit and said time stamp with said identified mobile network device; andmeans for comparing the calculated time stamp with a stored time stamp, which are activated in the event that said entry for said identified mobile network device already exists and contains said stored time stamp, and for updating said entry if said calculated time stamp is subsequent to said stored time stamp, and wherein said comparing means will also update said entry if said calculated time stamp matches said stored time stamp and said data packet indicates a shortest path which is shorter than the shortest path length contained in said entry. |
