zài / OSI / cān kǎo mó xíng / zhōng / shí tǐ céng / fù zé / bǎ / shù jù / zhuǎn huàn / chéng / bǐ tè liú在OSI参考模型中,实体层负责把数据转换成比特流。In the OSI reference model, the physical layer is responsible for converting data into bit streams.