A communication system includes a first communication apparatus included in an ad hoc network, and a second communication apparatus included in an ad hoc network, the second communication apparatus being coupled to a gateway and being configured to receive data from the first communication apparatus, wherein the first communication apparatus includes a memory, and a processor coupled to the memory and configured to acquire first information regarding communication quality between the first communication and each of a plurality of adjacent nodes in the ad hoc network, determine, based on the first information, a number of the adjacent nodes whose communication quality with the first communication apparatus is equal to or greater than a first value, and control, based on the number, a transmission amount of the data transmitted to the second communication apparatus through the ad hoc network.