A.3 Idle Channels
3GPP45.002GSM/EDGE Multiplexing and multiple access on the radio pathRelease 17TS
When a channel is idle, a dummy burst may be transmitted on C0 frequency channel with any options described in subclauses A 2.1.1, A 2.1.2, A 2.1.3.
Annex B (normative):
Multislot capability