the only reason for writing this would be that the encoding and protection of the SDCCH bursts are different than the TCH burst. Meaning that the SDCCH have less protection, therefore a higher BER.
But with HR and AMR (TCH with different codecs and protection), I doubt it makes any sense at all nowadays.
Maybe I’m missing something here, but I’ve NEVER seen anything like this before. Of course, it doesn’t mean it’s wrong. It would prove that i don’t know all about radio, which is certainly a correct assumption :))
Do they give any additional info about this? What’s the chapter about ?