Dynamically Adjusting Delivery of Content Between Terminal Device and Server

1. Communication equipment arranged between a terminal device and a server, the communication equipment comprising: a detector configured to detect transmitted data that is transmitted from the communication equipment to the terminal device and non-transmitted data that is not transmitted from the communication equipment to the terminal device, from service data transmitted from the server to the terminal device through the communication equipment; a first calculator configured to calculate a first cost of transmitting the non-transmitted data to the terminal device; a second calculator configured to calculate a second cost of transmitting, to the terminal device, a difference image between an image corresponding to the service data and an image corresponding to the transmitted data; and a transmission scheme decision unit configured to transmit the non-transmitted data to the terminal device when the second cost is equal to or greater than the first cost and transmit the difference image to the terminal device when the second cost is smaller than the first cost.

2. The communication equipment according to claim 1 , wherein the first calculator calculates the first cost based on a data size of the non-transmitted data; and the second calculator calculates the second cost based on a data size of the difference image.

3. The communication equipment according to claim 2 , further comprising a bandwidth estimator configured to estimate a communication bandwidth between the terminal device and the communication equipment, wherein the first calculator calculates, as the first cost, time required for transmitting the non-transmitted data to the terminal device based on the data size of the non-transmitted data and the communication bandwidth, and the second calculator calculates, as the second cost, time required for transmitting the difference image to the terminal device based on the data size of the difference image and the communication bandwidth.

4. The communication equipment according to claim 1 , further comprising a request unit configured to specify a service requested from the terminal device to the server and request the server for the specified service to acquire the same data as the service data, wherein the detector detects the non-transmitted data based on the data acquired by the request unit and based on the transmitted data.

5. The communication equipment according to claim 4 , wherein the second calculator generates a complete image corresponding to the service requested from the terminal device to the server based on the data acquired by the request unit, generates a current image corresponding to a display state of the terminal device based on the transmitted data, and generates the difference image by comparing the complete image and the current image.

6. The communication equipment according to claim 1 , further comprising an analyzer configured to decide whether the service data refers to data other than image data, and the transmission scheme decision unit transmits the non-transmitted data to the terminal device regardless of the first and second costs when the service data does not refer to data other than image data.

7. A communication control method performed in communication equipment arranged between a terminal device and a server, the communication control method comprising: detecting transmitted data that is transmitted from the communication equipment to the terminal device and non-transmitted data that is not transmitted from the communication equipment to the terminal device, from service data transmitted from the server to the terminal device through the communication equipment; calculating a first cost of transmitting the non-transmitted data to the terminal device; calculating a second cost of transmitting, to the terminal device, a difference image between an image corresponding to the service data and an image corresponding to the transmitted data; and transmitting the non-transmitted data to the terminal device when the second cost is equal to or greater than the first cost and transmitting the difference image to the terminal device when the second cost is smaller than the first cost.

8. A communication control method performed in a communication system in which service data is transmitted from a server to a terminal device through a gateway according to a request from the terminal device, wherein the gateway detects, from the service data, transmitted data that is transmitted from the gateway to the terminal device and non-transmitted data that is not transmitted from the gateway to the terminal device, the gateway calculates a first cost of transmitting the non-transmitted data to the terminal device, the gateway calculates a second cost of transmitting, to the terminal device, a difference image between an image corresponding to the service data and an image corresponding to the transmitted data, the gateway transmits the non-transmitted data to the terminal device when the second cost is equal to or greater than the first cost, and transmits the difference image to the terminal device when the second cost is smaller than the first cost, the terminal device generates an image corresponding to the transmitted data, and the terminal device superimposes the difference image transmitted from the gateway on the generated image to display the images.

9. Communication equipment arranged between a terminal device and a server, the communication equipment comprising a processor, wherein the processor performs a communication control method comprising: detecting transmitted data that is transmitted from the communication equipment to the terminal device and non-transmitted data that is not transmitted from the communication equipment to the terminal device, from service data transmitted from the server to the terminal device through the communication equipment; calculating a first cost of transmitting the non-transmitted data to the terminal device; calculating a second cost of transmitting, to the terminal device, a difference image between an image corresponding to the service data and an image corresponding to the transmitted data; and transmitting the non-transmitted data to the terminal device when the second cost is equal to or greater than the first cost and transmitting the difference image to the terminal device when the second cost is smaller than the first cost.