Download method and wireless communication device

1. A download method for downloading data, executed by a computer, the download method comprising:

assigning a download range of the data to each of the plurality of sessions based on size of the data, the plurality of sessions including a first session employing a first communication system and a second session employing a second communication system among a plurality of kinds of communication systems;

downloading the data of the download range assigned to each of the plurality of sessions in each of the plurality of sessions in parallel;

assigning a part of a first download range assigned to the first session to the second session when it is determined that a first communication situation in the first communication system is inferior to a second communication situation in the second communication system, the part of the first download rage being not downloaded;

downloading part of the data corresponding to the part of the first download range in the second session;

determining that the first communication situation is inferior to the second communication situation when a value obtained by multiplying a first throughput in the first session group by a given value is smaller than a value of a second throughput in the second session group; and

determining whether to assign the part of the first download range to the second session based on a comparison between a predicted value of the second throughput in the second session and an actual performance value of the first throughout in the first session,

wherein the part of first download range is assigned to the second session when a size of the part of the data is larger than a threshold.

2. The download method according to claim 1 , wherein the first session is identified from a first session group using the first communication system when it is determined that the first communication situation is inferior to the second communication situation, and the first session has a low throughput in the first group.

3. The download method according to claim 2 , wherein the second session is identified from a second session group using the second communication system when it is determined that the first communication situation is inferior to the second communication situation, and the second session has completed the downloading of assigned download range in the second session group.

4. A non-transitory computer-readable storage medium storing a download program for causing a computer to execute a process for downloading data, the process comprising:

assigning a download range of the data to each of the plurality of sessions based on size of the data, the plurality of sessions including a first session employing a first communication system and a second session employing a second communication system among a plurality of kinds of communication systems;

downloading the data of the download range assigned to each of the plurality of sessions in each of the plurality of sessions in parallel;

assigning a part of a first download range assigned to the first session to the second session when it is determined that a first communication situation in the first communication system is inferior to a second communication situation in the second communication system, the part of the first download rage being not downloaded;

downloading part of the data corresponding to the part of the first download range in the second session;

determining that the first communication situation is inferior to the second communication situation when a value obtained by multiplying a first throughput in the first session group by a given value is smaller than a value of a second throughput in the second session group; and

determining whether to assign the part of the first download range to the second session based on a comparison between a predicted value of the second throughout in the second session and an actual performance value of the first throughput in the first session,

wherein the part of first download range is assigned to the second session when a size of the part of the data is larger than a threshold.

5. The non-transitory computer-readable storage medium according to claim 4 , wherein the first session is identified from a first session group using the first communication system when it is determined that the first communication situation is inferior to the second communication situation, and the first session has a low throughput in the first group.

6. The non-transitory computer-readable storage medium according to claim 5 , wherein the second session is identified from a second session group using the second communication system when it is determined that the first communication situation is inferior to the second communication situation, and the second session has completed the downloading of assigned download range in the second session group.

7. A wireless communication device for downloading data, the wireless communication device comprising:

a memory; and

a processor coupled to the memory and configured to:

assign a download range of the data to each of the plurality of sessions based on size of the data, the plurality of sessions including a first session employing a first communication system and a second session employing a second communication system among a plurality of kinds of communication systems;

download the data of the download range assigned to each of the plurality of sessions in each of the plurality of sessions in parallel;

assign a part of a first download range assigned to the first session to the second session when it is determined that a first communication situation in the first communication system is inferior to a second communication situation in the second communication system, the part of the first download rage being not downloaded;

download part of the data corresponding to the part of the first download range in the second session;

determine that the first communication situation is inferior to the second communication situation when a value obtained by multiplying a first throughout in the first session group by a given value is smaller than a value of a second throughput in the second session group; and

determine whether to assign the part of the first download range to the second session based on a comparison between a predicted value of the second throughput in the second session and an actual performance value of the first throughput in the first session,

wherein the part of first download range is assigned to the second session when a size of the part of the data is larger than a threshold.

8. The wireless communication device according to claim 7 , wherein the first session is identified from a first session group using the first communication system when it is determined that the first communication situation is inferior to the second communication situation, and the first session has a low throughput in the first group.

9. The wireless communication device according to claim 8 , wherein the second session is identified from a second session group using the second communication system when it is determined that the first communication situation is inferior to the second communication situation, and the second session has completed the downloading of assigned download range in the second session group.