Real-time caption streaming over WiFi network

The use of laptop and handheld computers in educational environments has changed the nature of teaching, introducing new ways for students to interact with materials, teachers, and their classmates. Technological advances allow handheld devices to be equipped with faster processors and wireless interfaces, making the performance comparable to laptop computers. We propose a simple but effective scheme according to which each student can visualize in realtime and store the captions of the ongoing lecture. The system is based on IEEE 802.11b multicast protocols and implements a redundant transmission mechanism to mitigate the errors due to the unreliable wireless channel.