Abstract: A communication system including: a control apparatus configured to: for each combination of communication protocols that are used in communication networks respectively, estimate each transferring time length based on a size of a specified data and each overall throughput of the communication networks to which each combination of communication protocols is applied, each transferring time length being a time length taken for transferring the specified data in the communication networks except for time length taken for relay processing performed by at least one of relay communication apparatus, estimate each total transmission time length taken for transmission of the specified data from a source communication apparatus to a destination communication apparatus based on each stored relay processing time length and each estimated transferring time length, and select a combination of communication protocols that are to be used in the communication networks respectively, based on each estimated total transmission

Abstract: A communication device includes a memory configured to store a program, and a processor, based on the program, configured to control a number of communication segments that are allowed to be continuously transmitted after a first communication segment to be transmitted in accordance with a number of acknowledgments that have been received, and set a communication segment length of the first communication segment based on a length of time before completion of reception of an acknowledgment for a transmitted second communication segment.

Abstract: Before detecting a protocol switch trigger, transmission data of a first protocol is redundantly written into a transmission buffer for the first protocol. The transmission data of the first protocol is the same as transmission data of a second protocol. Upon detecting the protocol switch trigger, the second protocol is switched to the first protocol.

Abstract: A communication system including: a communication apparatus including: a transmitter, and a processor coupled to the transmitter and configured to: set an operation mode in the communication apparatus for forwarding data, to be one of a first operation mode and a second operation mode, the first operation mode in which the data is forwarded without a protocol conversion, the second operation mode in which the data is forwarded with the protocol conversion, detect identification information of the data included in the data that is received from an upstream communication apparatus and forwarded to a downstream communication apparatus, and when the operation mode in the communication apparatus is the first operation mode and the identification information detected by the first processor is a first given value, switch the operation mode in the communication apparatus from the first operation mode to the second operation mode.

Abstract: A TCP node stores a congestion window size before congestion is detected, the congestion window size limiting the amount of data to be transmitted. If congestion is detected, the TCP node reduces a current congestion window size to a predetermined size. If path switching subsequently occurs after congestion is detected, the TCP node uses a round-trip time or bandwidth information of a path after switching to correct the congestion window size before congestion detection. The TCP node then changes the reduced congestion window size to the corrected size.

Abstract: A communication device including: a processor configured to perform a wireless communication protocol including an upper layer and a lower layer, wherein the processor is configured to estimate, based on a round trip time measured at the upper layer in case of carrying out a retransmission control at the lower layer and a time taking for retransmissions at the lower layer, a first estimated round trip time, to estimate, based on the number of times of packet loss at the upper layer in case of carrying out the retransmission control at the lower layer, and the number of times of successful transmission at the upper layer being recovered by the retransmission control, a first estimated packet loss rate, and to obtain, based on the first estimated round trip time and the first estimated packet loss rate, a first estimated throughput in case of not carrying out the retransmission control.

Abstract: A relay device is arranged on a path of a Transmission Control Protocol (TCP) packet transmitted and received between a transmission-side end device and a reception-side end device. The relay device stores packet information obtained by snooping on a first TCP packet that is addressed to the reception-side end device and received from the transmission-side end device and on a second TCP packet that is addressed to the transmission-side end device and received from another relay device that is arranged between the relay device and the reception-side end device on the path. The relay device performs, based on the packet information, first communication control between the relay device and the another relay device, where the first communication control is independent of second communication control that is performed between the transmission-side end device and the reception-side end device.

Abstract: A communication control device measures a size of burst data transmitted from a first device through the use of a predetermined protocol in a transport layer. The communication control device selects a protocol ruled by an algorithm with the smallest latency, which is estimated from the measured size of burst data and characteristics of a network, from among plural protocols used in the transport layer. The communication control device terminates the communication of the burst data transmitted through the predetermined protocol from the first device and transmits the burst data to a destination through the use of the selected protocol.

Abstract: A transmission control method includes performing communication between a transmission source communication device and a transmission destination communication device by using a transmission control protocol which includes a plurality of congestion control functions corresponding to a plurality of congestion control methods, respectively, and causing, when the transmission source communication device and the transmission destination communication device switch from a first congestion control function to a second congestion control function, at least one of a plurality of parameters for controlling operating states in the first congestion control function to be inherited by a parameter for controlling an operating state in the second congestion control function.

Abstract: A relay apparatus for performing relay possessing is disclosed. The relay apparatus includes a first logical relay unit; a second logical relay unit; a sending unit configured to add a packet header including a first protocol identifier or a second protocol identifier registered in a protocol assignment unit to a packet to be sent by the first logical relay unit or the second logical relay unit, and to send the packet to a network; a receiving unit configured to pass a received packet to the first logical relay unit or the second logical relay unit by referring to the protocol assignment unit based on a protocol identifier in a packet header of the received packet; and a switching process unit configured to change correspondence relationship for the first and the second protocol identifiers to switch between the first logical relay unit and the second logical relay unit.

Abstract: A communication device includes a memory configured to store a program, and a processor, based on the program, configured to control a number of communication segments that are allowed to be continuously transmitted after a first communication segment to be transmitted in accordance with a number of acknowledgments that have been received, and set a communication segment length of the first communication segment based on a length of time before completion of reception of an acknowledgment for a transmitted second communication segment.

Abstract: In a wireless communication system, time point information is transmitted from a second wireless base station. The time point information indicates a time point at which service information is transmitted from the second wireless base station. Moreover, at the time point indicated by the time point information, the service information is transmitted from the second wireless base station. On the wireless terminal side, firstly, the time point information is obtained in a first non-communication period in which communication with the first wireless base station is temporarily stopped. Then, the service information is obtained in a second non-communication period which is ensured in accordance with the time point indicated by the time point information.

Abstract: A wireless connecting method includes a connection monitoring step, a connection parameter retaining step, and a connection restoring step. The connection monitoring step monitors the wireless connection between the communication terminal device and the base station. The connection parameter retaining step sets a communication session retention time period that is longer than a connection parameter retention time period, and retains a connection parameter. A connection parameter when the wireless connection is disconnected is retained in at least one of the communication terminal device and the base station for the communication session retention time period exceeding the connection parameter retention time period.

Abstract: An information processor apparatus includes a memory which stores a program, and a processor, based on the program, configured to, detect a packet that is transmitted from a management device to a second node that is included in a second network, and that triggers a request packet transmitted from the second node to a first node that is included in a first network, by monitoring communication from the management device that manages the first node and the second node that obtains data from the first node through a third network, and execute a proxy request by transmitting the request packet to the first node when the packet is detected and a connection is made with the first network.

Abstract: A virtual interface having a global address of a physical interface on an Internet side of a gateway is provided in a terminal. An application unit of the terminal transmits a packet to the Internet using the virtual interface. The packet is transferred to the gateway through a downlink transfer path. The gateway transmits the packet from the physical interface on the Internet side to the Internet.

Abstract: A TCP node stores a congestion window size before congestion is detected, the congestion window size limiting the amount of data to be transmitted. If congestion is detected, the TCP node reduces a current congestion window size to a predetermined size. If path switching subsequently occurs after congestion is detected, the TCP node uses a round-trip time or bandwidth information of a path after switching to correct the congestion window size before congestion detection. The TCP node then changes the reduced congestion window size to the corrected size.

Abstract: A handover method, in a wireless communication system having a mobile station and a plurality of base stations, for performing handover of the mobile station from a connected base station to a neighbor base station, the method having the steps of: deciding that neighbor base station information non-reception handover is establish; searching a connectable neighbor base station; acquiring identification information for the neighbor base station; transmitting a handover request including the acquired identification information; transmitting, in the connected base station received the handover request, to the mobile station, service level information included with in a handover response, and deciding a handover destination based on the service level information.

Abstract: A wireless terminal apparatus is capable of switching between a first mode in which connection to a wireless access network is established and a second mode in which the connection to the wireless access network is temporarily released. The wireless terminal apparatus has a data processing unit and a transmitting unit. The data processing unit generates data to be transmitted to the wireless access network. The transmitting unit includes at least a part of the data generated by the data processing unit during the second mode in a control message to be transmitted to the wireless access network in the second mode, and transmits the data.

Abstract: A communication setting method includes receiving, at a server in a network to be connected to another network by a plurality of connected devices, a setting request from a terminal to the server, selecting, at the server, one of the plurality of connected devices based on terminal location information regarding the location of the terminal relating to the received setting request, transmitting a setting response including identification information for identifying the selected connected device form the server to the terminal, setting, at the terminal, the connected device of this terminal based on the identification information included in the setting response.

Abstract: A communication control method, for a radio communication system including a radio base station, a radio terminal, and a relay station that receives a radio signal transmitted from the radio base station and relays the radio signal to the radio terminal at a transmission frequency different from a reception frequency, includes broadcasting information on one or more transmission frequencies of radio base stations or relay stations from the radio base station; and determining, by the radio terminal, whether transmission-source identification information included in the radio signals that are received before and after switching the reception frequency match, the switching being conducted based on the information broadcasted from one of the radio base station directly and via the relay station, wherein if the radio terminal determines that the transmission-source identification information matches, the radio terminal omits a terminal registering procedure after frame-synchronization with the radio communication