data sounds over audio

I am developing a system for online games over satellite transmition. We need to transfer data on one of the two audio channels. This channel is clean and is resereved only for the data transmition so you can assume that there is nothing else running on this channel. The code sould handle the 2 sides. 1 side will recive a string for transmition (Max 100 bytes) it will convert the string into sounds that will be out from the sound card output and then will be broadcasted. 2. second side (recieving side) will recive the audio sounds into the microphone of the sound card and will open the sounds back to its original data format. 3. every string that is sended sould be treated is a packet that has a checksum in the end to ensure that the message is not currupted. If when openning the packet an error on the checksum is out then the function sould return error and nothing else. We will take care of sending each message few times to ensure it will get with no problems. We will prefer to have a vb code that will be a part of the big project, if not then it has to be a lib that will provide this functionality. About the speed. The speed is not a critical factor here, so this is not a modem algorithems here. We are talking about 50-100 Bytes a second which can be done by simple sounds. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Installation package that will install the software (in ready-to-run condition) on the platform(s) specified in this bid request. 3) Exclusive and complete copyrights to all work purchased. (No GPL, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site). ## Platform Windows Xp.