  We consider the anchor placement problem in localization based on one-way
ranging, in which either the sensor or the anchors send the ranging signals.
The number of anchors deployed over a geographical area is generally sparse,
and we show that the anchor placement can be formulated as the design of a
sparse selection vector. Interestingly, the case in which the anchors send the
ranging signals, results in a joint ranging energy optimization and anchor
placement problem. We make abstraction of the localization algorithm and
instead use the Cram\'er-Rao lower bound (CRB) as the performance constraint.
The anchor placement problem is formulated as an elegant convex optimization
problem which can be solved efficiently.
