Can bb switch from SACCH to TCH directly?

[Chengcheng Gou]

hi,

i am studying the TCH ,and can get the channel discription from SACCH,
and My question is when I receive the ASS_CMD, I use l1ctl_tx_dm_est_req_h0
and jump to the new channel,but I can`t capture the TCH,why?

Thanks!