I found that with limited resourses such as found in 8052 systems its all too easy to get carried away with comms stacks which tie up the processor.It is better to do as much as possible at the physical layer(CRC,error correction etc and so on) in hardware so that you can keep the higher levels of the stack looking at the OSI model for example,as nice and tight little functions.
Thats my advice anyway,but you can do whatever as I have got a new job today,HURRAH!!