A wireless display device comprising: circuitry configured to wirelessly receive content data using a UDP and IEEE 802.11, the content data being directly transmitted to the wireless display device from a wireless communication device; and circuitry configured to wirelessly transmit capability information indicating that the wireless display device can change the display orientation of an image on a display unit of the wireless display device and to transmit information depending on a display orientation of the wireless display device using a TCP, the wireless display device further comprising a sensor for generating information indicating the display orientation of the wireless display device, and wherein the information depending on the display orientation comprises information generated by the sensor indicating the display orientation, wherein the wireless display device is configured to receive capability information indicating the ability to generate image data conforming to a display orientation of an image on the display unit from the wireless communication device, and wherein, the wireless display device is configured to transmit the capability information indicating that the wireless display device can change the display orientation of an image on a display unit before receiving the capability information indicating the ability to generate image data conforming to a display orientation of an image on the wireless display device, and in response to receiving the capability information indicating the ability to generate image data conforming to a display orientation of an image on the wireless display device, the wireless display device is configured to recognize that the wireless communication device has the function to generate and transmit image data conforming to a display orientation of an image on the wireless display device and to then start periodic transmission of the sensor information obtained by the sensor via the said circuitry configured to wirelessly transmit, using the TCP, capability information comprising the sensor information circuitry configured to wirelessly receive content data using a UDP and IEEE 802.11, the content data being directly transmitted to the wireless display device from a wireless communication device; and circuitry configured to wirelessly transmit capability information indicating that the wireless display device can change the display orientation of an image on a display unit of the wireless display device and to transmit information depending on a display orientation of the wireless display device using a TCP, the wireless display device further comprising a sensor for generating information indicating the display orientation of the wireless display device, and wherein the information depending on the display orientation comprises information generated by the sensor indicating the display orientation, wherein the wireless display device is configured to receive capability information indicating the ability to generate image data conforming to a display orientation of an image on the display unit from the wireless communication device, and wherein, the wireless display device is configured to transmit the capability information indicating that the wireless display device can change the display orientation of an image on a display unit before receiving the capability information indicating the ability to generate image data conforming to a display orientation of an image on the wireless display device, and in response to receiving the capability information indicating the ability to generate image data conforming to a display orientation of an image on the wireless display device, the wireless display device is configured to recognize that the wireless communication device has the function to generate and transmit image data conforming to a display orientation of an image on the wireless display device and to then start periodic transmission of the sensor information obtained by the sensor via the said circuitry configured to wirelessly transmit, using the TCP, capability information comprising the sensor information