Communication device, communication method, and computer program product

A communication method, characterized by comprising the steps of:

• transmitting a plurality of measurement packets to another communication device that is connected to a network while successively varying a transmitting interval;
• determining, in a case where the plurality of measurement packets have been transmitted, a location of a usable bandwidth in relation to a first bandwidth range, based on a result packet that is transmitted from the other communication device, the first bandwidth range being a range within which bandwidths are measured, the usable bandwidth being one of the bandwidths that can be used in the network, and the result packet containing information that pertains to a relationship between the transmitting interval and a receiving interval at which the measurement packets are received by the other communication device;
• resetting the first bandwidth range to a second bandwidth range in accordance with the determining of the location of the usable bandwidth in relation to the first bandwidth range, the second bandwidth range being a range within which the bandwidths are measured and in which at least one of an upper limit and a lower limit is different from the corresponding limit in the first bandwidth range;
• selecting, from among a plurality of bandwidths that have been selected from within the second bandwidth range and based on the setting of the second bandwidth range, a bandwidth that will be used when the measurement packets are transmitted to the other communication device, in order to determine whether the usable bandwidth is located within the second bandwidth range that has been set;
• and
• transmitting the measurement packets to the other communication device using the selected bandwidth.

A computer program product stored on a non-transitory computer-readable medium, comprising instructions for causing a computer of a communication device that is connected to a network to carry out communication with another communication device to perform the steps of:

• transmitting a plurality of measurement packets to another communication device that is connected to a network while successively varying a transmitting interval;
• determining, in a case where the plurality of measurement packets have been transmitted, the location of a usable bandwidth in relation to a first bandwidth range, based on a result packet that is transmitted from the other communication device, the first bandwidth range being a range within which bandwidths are measured, the usable bandwidth being one of the bandwidths that can be used in the network, and the result packet containing information that pertains to a relationship between the transmitting interval and a receiving interval at which the measurement packets are received by the other communication device;
• resetting the first bandwidth range to a second bandwidth range in accordance with the determining of the location of the usable bandwidth in relation to the first bandwidth range, the second bandwidth range being a range within which the bandwidths are measured and in which at least one of an upper limit and a lower limit is different from the corresponding limit in the first bandwidth range;
• selecting, from among a plurality of bandwidths that have been selected from within the second bandwidth range and based on the setting of the second bandwidth range, a bandwidth that will be used when the measurement packets are transmitted to the other communication device, in order to determine whether the usable bandwidth is located within the second bandwidth range that has been set;
• and
• transmitting the measurement packets to the other communication device using the selected bandwidth.