Abstract: Techniques for facilitating secure and scalable data transfers using a hybrid blockchain-based approach are provided. In one embodiment, a first computer system at a first site can transmit a token to a second computer system at a second site, where the token includes metadata regarding a data set to be transferred from the first computer system to the second computer system and one or more cloud storage service addresses where the data set will be temporarily stored. The token can be transmitted using a blockchain network that is accessible to the first and second computer systems via a public network. The first computer system can then upload the data set to the one or more cloud storage service addresses via the public network, and the second computer system can download the data set from the one or more cloud storage service addresses via the public network.

Abstract: An information terminal 10 successively receives a plurality of packets that configure distribution data from an information distribution server 20, and requests the information distribution server 20 to change a bit rate of the packets that configure the distribution data, if it is judged that congestion occurs in communication with the information distribution server 20 based on a change in time interval from transmission to reception of each of the successively received packets, and if it is judged that a packet loss rate, which is a rate of a loss packet corresponding to a loss included in the packets transmitted from the information distribution server 20 and calculated based on the successively received packets, is increased as compared with a value obtained by multiplying a packet loss rate before the packets that configure the distribution data are received, by a predetermined weight.

Abstract: Techniques for facilitating secure and scalable data transfers using a hybrid blockchain-based approach are provided. In one embodiment, a first computer system at a first site can transmit a token to a second computer system at a second site, where the token includes metadata regarding a data set to be transferred from the first computer system to the second computer system and one or more cloud storage service addresses where the data set will be temporarily stored. The token can be transmitted using a blockchain network that is accessible to the first and second computer systems via a public network. The first computer system can then upload the data set to the one or more cloud storage service addresses via the public network, and the second computer system can download the data set from the one or more cloud storage service addresses via the public network.

Abstract: An information terminal sequentially transmits one or more packets to an information distribution server, receives acknowledgments for the transmitted packets from the information distribution server, and records a round trip time and occurrence of packet loss for each of the transmitted packets. Among one or more packet sequences, the information terminal counts the number of packet sequences which are such that the number of packet losses included in each of the packet sequences and an increase state of the round trip time for packets included in the packet sequence satisfy respective predetermined conditions. Each of the one or more packet sequences has multiple continuous packets including one or more packets, for which packet loss is recorded among the transmitted packets, at the top. The information terminal calculates a packet loss ratio on the basis of the counted number and the number of transmitted packets.

Abstract: A mobile terminal obtains a measurement value of a round-trip time in a communication channel used for communication with a server and a measurement value of a packet loss ratio in the communication channel (S502 and S503). Then, the mobile terminal determines whether or not a retransmission timeout is occurring in the server (S504, S505, and S506). If a retransmission timeout is occurring in the server, the mobile terminal calculates an estimate value of the bandwidth in the communication channel by using a special throughput equation including a timeout time (S507). On the other hand, if a retransmission timeout is not occurring in the server, the mobile terminal calculates an estimate value of the bandwidth by using a normal throughput equation which does not include a timeout time.

Abstract: An information terminal 10 successively receives a plurality of packets that configure distribution data from an information distribution server 20, and requests the information distribution server 20 to change a bit rate of the packets that configure the distribution data, if it is judged that congestion occurs in communication with the information distribution server 20 based on a change in time interval from transmission to reception of each of the successively received packets, and if it is judged that a packet loss rate, which is a rate of a loss packet corresponding to a loss included in the packets transmitted from the information distribution server 20 and calculated based on the successively received packets, is increased as compared with a value obtained by multiplying a packet loss rate before the packets that configure the distribution data are received, by a predetermined weight.

Abstract: An information terminal sequentially transmits one or more packets to an information distribution server, receives acknowledgments for the transmitted packets from the information distribution server, and records a round trip time and occurrence of packet loss for each of the transmitted packets. Among one or more packet sequences, the information terminal counts the number of packet sequences which are such that the number of packet losses included in each of the packet sequences and an increase state of the round trip time for packets included in the packet sequence satisfy respective predetermined conditions. Each of the one or more packet sequences has multiple continuous packets including one or more packets, for which packet loss is recorded among the transmitted packets, at the top. The information terminal calculates a packet loss ratio on the basis of the counted number and the number of transmitted packets.

Abstract: A mobile terminal obtains a measurement value of a round-trip time in a communication channel used for communication with a server and a measurement value of a packet loss ratio in the communication channel (S502 and S503). Then, the mobile terminal determines whether or not a retransmission timeout is occurring in the server (S504, S505, and S506). If a retransmission timeout is occurring in the server, the mobile terminal calculates an estimate value of the bandwidth in the communication channel by using a special throughput equation including a timeout time (S507). On the other hand, if a retransmission timeout is not occurring in the server, the mobile terminal calculates an estimate value of the bandwidth by using a normal throughput equation which does not include a timeout time.