An Air Carrier Captain noted that they were unable to contact ATC or Company Operations after leaving the gate with the Tower closed. Captain returned to the gate; making phone calls to get ATC's attention.

Narrative

We were scheduled for a pre-dawn departure. After boarding and de-icing; taxied to threshold of Runway X for departure and began attempting to contact ATC for clearance. We tried multiple frequencies all without any response. Multiple ACARS messages were sent between us and Dispatch without a resolution. Multiple attempts were made to call Company Operations with no response; even when our Dispatcher said they had them on the phone at the time. We even waited until after XA:00 local time to try ATC again to see if we could make contact. At that time; we were at our limit on fuel and on our de-ice hold over time and were forced to return to the gate. Once back at the gate; I went into Operations and called Flight Service; who notified me to go back to aircraft and try again on 121.40 for clearance. Once back at aircraft; we were able to successfully contact ATC on 121.40 for clearance and continue as planned. My major problem with this whole scenario; aside from not being able to contact anyone for a clearance on the ground at this airport and that time of morning; is that we made multiple attempts on 121.50 to contact ATC and to our operations frequency with no response. This is a serious safety issue. What if we had been on fire or had an attempted flight deck breach? We were completely on our own. For a Part 121 scheduled passenger airline; this is unacceptable. There has always been a problem with communications at this airport. ATC does not come to work until XA:00; this is a problem when we have an earlier scheduled departure; but even at and after XA:00; we could not raise them. Additionally; we should have been able to reach our operations people and we could not until we were back at the gate. There must be serious communications problems at this airport. Suggestions: Number one; no matter what the circumstances; an aircraft should always be able to reach someone on 121.50. We were not; this is unacceptable and dangerous. Number two; if we are going to have departures at that early hour then there should be a Controller on duty whom we can contact for a clearance. If not; then the departures should not be scheduled until such time as ATC is available; particularly at non tower uncontrolled airports. If the Company expects us to call Flight Service from Operations; then a Company memo should be distributed accordingly to the pilot group. To do so from Operations; prior to boarding with an expected wheels up time; ATC should be advised of our intent of conducting our operations out of this small airport and similar airports in this way and in the future.