Patent ID: 8341701
Filing Date: 2012-12-25
Classification: H04L

Abstract:
1. A communication method for controlling communication between a communication apparatus as a request source which transmits a request for transmission of content data and a communication apparatus as a request destination which responds to the request for transmission of content data, the method comprising steps of: sharing authentication information between the request destination and the request source so that the request destination and the request source store the authentication information, respectively; transmitting a measurement preparation request from the request destination to the request source, and generating, by the request destination, first pre-measurement information by using the authentication information stored in the request destination; upon receiving the measurement preparation request by the request source, transmitting a measurement preparation response from the request source to the request destination, and generating, by the request source, second pre-measurement information by using the authentication information stored in the request source; after the steps of transmitting a measurement preparation request and transmitting a measurement preparation response, transmitting a measurement request from the request destination to the request source, the measurement request including first data created based on the first pre-measurement information, the first data being different from the first pre-measurement information; upon receiving the measurement request by the request source, transmitting a measurement response from the request source to the request destination, the measurement response including second data created based on the second pre-measurement information, the second data being different from the second pre-measurement information; measuring a period of time from the transmission of the measurement request to the reception of the measurement response, as a round trip time; determining, by the request destination, whether the round trip time is less than or equal to a reference value; upon determining that the round trip time is less than or equal to the reference value, determining, by the request destination, whether the second data received from the request source is valid based on the first pre-measurement information; sending a verification request from the request destination to the request source, when the second data is valid; upon receiving the verification request, determining, by the request source, whether the first data received from the request destination is valid based on the second pre-measurement information; sending a verification result from the request source to the request destination, when the first data is valid; upon receiving the verification result, determining, by the request destination, that the request source is an eligible device as a transmission destination of the content data; and upon determining that the request source is an eligible device as a transmission destination, registering, by the request destination, device identification information for identifying the request source in the request destination, wherein: the first data is a portion of the first pre-measurement information, and is also a portion of the second pre-measurement information, and the second data is a portion of the second pre-measurement information, and is also a portion of the first pre-measurement information, and the measurement preparation request and the measurement preparation response are not used in measuring the round trip time.