Patent ID: 7791637

Claim:
A data transmission system to transmit digital data through a wireless transmission path, comprising: a first device comprising: a communication condition detecting section which detects communication condition of a network, a data supplying section which supplies digital data containing at least one of video data and audio data, a bit-rate converting section which converts bit rate of the digital data supplied by the data supplying section, a transmission buffer which stores the bit-rate converted digital data, a transmission communicating section which transmits and receives the digital data, and a channel switching section which switches a communication channel; and a second device comprising: a reception communicating section which transmits and receives digital data, a reception buffer which stores the received digital data, and a buffer storage amount detecting section which detects data storage amount in the reception buffer, wherein the communication condition detecting section comprises a jamming detecting section which detects jamming and a communication speed detecting section which detects communication speed in a communication channel, when the jamming detecting section detects jamming as well as the communication speed detecting section detects that a band width of the communication channel is below a predetermined value, the bit-rate converting section converts bit rate of the digital data into bit rate determined based on the time required to switch the communication channel to newly establish a link and based on the capacity of the reception buffer, and the channel switching section, on the basis that the buffer storage amount detecting section determines that the predetermined bit-rate converted digital data is stored to bring the data storage amount in the reception buffer to an upper limit, switches the communication channel to a channel where influence of jamming is less.