said by BobCat67:also band rate are now based on how many phone numbers are for a certain area the smaller and or populated therefor how many phone numbers are available determine the band rate if lots are avail they can assign a dead number to the dry loop since all dry loops need a number to link to the network it just wont let you call out on that line or recv calls band F G etc all have less #'s available in their area so higher charge to assign what;s left where as bands A and B lots are avail so less cost
Phone numbers are assigned to telephone companies in blocks of 10,000. A village of 500 with it's own exchange is assigned the same size block as a small town with 5000 residents.
The rate band you are in is determined not by the number of telephone numbers available, but by the subscriber density of the exchange. This is based on the idea that it costs Bell more to maintain the physical plant in a low density exchange, so the cost per circuit is higher.