Communication terminals and mobile communication system including the same
The transmission speed of downlink communication information to be received by communication terminals has been improved. A mobile communication system comprises a plurality of communication terminals that wirelessly communicate with each other; and a base station that is requested, based on the transmission speeds of the communication terminals, by the communication terminals to transmit downlink communication information. Each local communication terminal has a relay requesting device that receives information on the transmission speed of another communication terminal and that, when the transmission speed of the other communication terminal is greater than that of the local communication terminal, transmits, to the other communication terminal, identification information to be used for the base station to identify the local communication terminal or the other communication terminal, thereby requesting the other communication terminal to relay communication information addressed to the local communication terminal. The base station has a terminal identifying/transmitting device that transmits, based on the identification information of the local communication terminal, the communication information addressed to the local communication terminal to the local communication terminal via the other communication terminal.
1. A communication terminal that requests a base station to transmit downlink communication information based on a transmission speed of the communication terminal while the communication terminal and a remote station wirelessly communicate with each other, the communication terminal comprising:
a processor;
a communication device for performing wireless communication with the base station;
a transmission speed computing device for computing a transmission speed in the wireless communication with the base station according to a reception state in the wireless communication with the base station;
a second communication device for performing wireless communication with the remote station;
a transmission speed comparing device for acquiring information on a transmission speed in wireless communication between the remote station and the base station by means of the second communication device and comparing the transmission speed of the remote station obtained thereby and the transmission speed of the communication terminal computed in the transmission speed computing device; and
a relay requesting device for requesting the remote station to provide the base station with a transmission request for transmitting information addressed to the communication terminal from the base station to the remote station, by means of the second communication device, if the transmission speed of the remote station is higher than that of the communication terminal as a result of the comparison by the transmission speed comparing device,
wherein the information addressed to the communication terminal transmitted from the base station to the remote station is obtained by the second communication device if the relay requesting device has made the request.
2. The communication terminal of claim 1 , wherein the relay requesting device sends the request by providing the remote station with identification information to be used for the base station to identify the communication terminal or the remote station.
3. The communication terminal of claim 1 , further comprising: a control device for controlling the communication device to stop the wireless communication with the base station if the second communication device acquires the communication information addressed to the communication terminal from the remote station.
4. A mobile communication system comprising a first communication terminal and a second communication terminal that wirelessly communicate with each other and a base station that is requested by the communication terminals to transmit downlink communication information based on transmission speeds of the communication terminals, the first communication terminal comprising:
a communication device for performing wireless communication with the base station;
a transmission speed computing device for computing a transmission speed in the wireless communication with the base station according to a reception state in the wireless communication with the base station;
a second communication device for performing wireless communication with the second communication terminal;
a transmission speed comparing device for acquiring information on a transmission speed in wireless communication between the second communication terminal and the base station by means of the second communication device and comparing the transmission speed of the second communication terminal obtained thereby and the transmission speed of the first communication terminal computed in the transmission speed computing device; and
a relay requesting device for requesting the second communication terminal to provide the base station with a transmission request for transmitting information addressed to the first communication terminal from the base station to the second communication terminal, by means of the second communication device, if the transmission speed of the second communication terminal is higher than that of the first communication terminal as a result of the comparison by the transmission speed comparing device,
wherein the relay requesting device sends the request by providing the second communication terminal with identification information to be used for the base station to identify the first communication terminal or the second communication terminal,
the second communication terminal comprising: a relaying device for sending the request to the base station if the request has been received from the first communication terminal, and
the base station comprising: a local/other station identifying/transmitting device for providing the second communication terminal with communication information addressed to the first communication terminal based on the identification information of the first communication terminal obtained according to the request from the second communication terminal, and
wherein the relaying device of the second communication terminal provides the first communication terminal with the communication information addressed to the first communication terminal if the communication information addressed to the first communication terminal has been received from the base station.
5. The mobile communication system of claim 4 , wherein the second communication terminal further comprises a transmission speed computing device for computing a transmission speed in wireless communication with the base station according to a reception state in the wireless communication with the base station, and
wherein the relaying device transmits information on the transmission speed of the second communication terminal computed in the transmission speed computing device to the first communication terminal if communication information addressed to the second communication terminal is absent.
6. The mobile communication system of claim 4 , wherein the base station comprises:
a scheduling device for determining transmission sequences and communications traffics relative to the first and second communication terminals based on the transmission speeds relative to previous communications traffics of the first and second communication terminals; and
a communications traffic correcting device for treating the communication information transmitted to the second communication terminal having relayed the information as that transmitted to the first communication terminal having made a relay request, when computing the previous communications traffics of the first and second communication terminals.
7. The mobile communication system of claim 6 , wherein the communications traffic correcting device subtracts a communications traffic based on the communication information transmitted to the second communication terminal having relayed the information from a previous communications traffic of the second communication terminal having relayed the information and adds the subtracted communications traffic to a previous communications traffic of the first communication terminal having made a relay request.
8. The mobile communication system of claim 4 , wherein the first communication terminal further comprises
a control device for controlling the communication device to stop the wireless communication with the base station if the second communication device acquires the communication information addressed to the first communication terminal from the second communication terminal.