FWIW, here's a simple little start-up script to get a nice looking tmux session with everything running.
#!/bin/sh
config_dir="$(readlink -f "$(dirname "$0")")" openbsc_config="$config_dir/open-bsc.cfg" osmobts_config="$config_dir/osmo-bts.cfg" hlr_db="$config_dir/hlr.sqlite3" window_title="GSM"
tmux new-session -s "$window_title" -n close-me -d
tmux new-window -n OpenBSC -t "$window_title" tmux send-keys -t OpenBSC "osmo-nitb -c '$openbsc_config' -l '$hlr_db' \ -P -C --debug=DRLL:DCC:DMM:DRR:DRSL:DNM" Enter
tmux new-window -n OsmoBTS -t "$window_title" tmux send-keys "osmobts-trx -c '$osmobts_config'" Enter
tmux new-window -n OsmoTRX -t "$window_title" tmux send-keys "osmo-trx" Enter
tmux new-window -n BSC-Control -t "$window_title" tmux send-keys -t BSC-Control "telnet localhost 4242" enter
tmux new-window -n BTS-Control -t "$window_title" tmux send-keys -t BTS-Control "telnet localhost 4241" enter
tmux set-option -t "$window_title" status on tmux kill-window -t close-me tmux select-window -t OpenBSC tmux attach -t "$window_title"