A
wireless terminal receives signaling information, pertaining to a reference
signal transmission in at least one specifically designated sub frame, the signaling information including a
list, the
list including
base station identities. The terminal determines, from at least one of the
base station identities in the
list, the time-frequency resources associated with a reference
signal transmission intended for observed
time difference of arrival (OTDOA) measurements from a transmitting
base station associated with said one base
station identity. The
time of arrival of a transmission from the transmitting base
station, relative to reference timing, is measured. The
wireless terminal can receive a command from a serving
cell to start performing inter-frequency OTDOA measurement on a frequency layer containing reference signals, the frequency layer distinct from the serving frequency layer, the serving frequency layer not containing positioning reference signals. The
wireless terminal can perform OTDOA measurements subsequent to the reception of the command on a carrier frequency different from the serving
cell carrier frequency. A base
station transmitter can jointly schedule a reference
signal transmission from a plurality of base station transmitters for the purpose of OTD
estimation enhancement, and transmit identical reference signals from the plurality of base station transmitters, the reference signals being identical both in the signal sequence and time-frequency resources used for transmission.