  To provide stable and high data rate wireless access for passengers in the
train, it is necessary to properly deploy base stations along the railway. We
consider this issue from the perspective of service, which is defined as the
integral of the time-varying instantaneous channel capacity. With large-scale
fading assumption, it will be shown that the total service of each base station
is inversely proportional to the velocity of the train. Besides, we find that
if the ratio of the service provided by a base station in its service region to
its total service is given, the base station interval (i.e. the distance
between two adjacent base stations) is a constant regardless of the velocity of
the train. On the other hand, if a certain amount of service is required, the
interval will increase with the velocity of the train. The above results apply
not only to simple curve rails, like line rail and arc rail, but also to any
irregular curve rail, provided that the train is travelling at a constant
velocity. Furthermore, the new developed results are applied to analyze the
on-off transmission strategy of base stations.
