nanoBTS multi-TRX setup

Hi all, I was just reading the wiki page about the nanoBTS multi-TRX setup. Two things are not clear to me. 1. What is the purpose of the "RF cable"? Is the TX port of the master BTS looped through the second BTS? Or hase every nanoBTS his own TRX/RX? I am asking because I would like to use a nanoBTS-Booster with the multi-TRX setup and therefore require a combined RF signal. 2. The example example "openbsc.cfg" configures the trx 1 as follows: timeslot 0 phys_chan_config CCCH+SDCCH4 timeslot 1 phys_chan_config SDCCH8 Is this really needed? My first idea was to configure the second trx to TCH/F only. Best regards Konrad Meier