GCI has service in Naknek. ACS uses their towers as well. I do not know if other carriers use the towers. Google GCI or ACS and give them a call to see if your service provider will use the tower. I have seen people using smart phones around there. There is 4g service out there. I have been commercial fishing out there for over ten years.
I have used a cell phone by the X. If you are on a boat fishing this summer, that is the "Y." It is where the tenders hang out at.
Here is ACS' coverage map. You can zoom in on the Naknek area. It looks like they have service at all of the major fishing villages in the area.
http://www.alaskacommunications.com/Online-Care/Service-Coverage.aspx
Have fun, good luck, and be safe out here.
Here is some boat porn
This shot took me at least a dozen tries to get the moon inside the eye.
We were about to anchor at the "Y" to wait until the next opener. Fish and game tells you when the next time you are allowed to fish.
This is from a house in South Naknek looking into the River Mouth around midnight. You can see the "Y." It is the line of boats behind the crane.
This landing craft got stuck on the sand bar in the middle of the river for a tide.
Here is a boat getting ready to deliver fish