gsm

record gsm {
  cid: geran-cid,
  lac: lac,
  local-id: option​<gsm-local-id>,
  mcc: mcc,
  mnc: mnc,
  nmr: option​<gsm-nmr-array>,
  rx-level: option​<rx-level>,
  ta: option​<gsm-timing-advance>,
}