| 摘要 |
PROBLEM TO BE SOLVED: To reduce changeover time of a communication path. ! SOLUTION: A first communication device comprises a reception unit, a calculation unit, a determination unit, and a transmission unit. The reception unit received a first packet from a second communication device adjacent to the first communication device. The first packet includes information on a device communicable through the second communication device at a first water level which is the present water level in a vicinity region and a request for determining a path to a collection device at a second water level corresponding to a water level prediction value in the region. The calculation unit calculates, for each communication device reported by the first packet, an index value of a situation of communication with the first communication device in the case that the region is at the second water level. The determination unit determines that a device having a relatively excellent communication situation shown by its index value is |
