A method in a wireless communications device having a first protocol stack
for use with a first radio access technology (RAT) and a second protocol
stack for use with a second RAT, the first protocol stack comprising a
reordering component associated with a first layer of the first protocol
stack and arranged to implement a data reordering queue, the method for
transitioning from the first RAT to the second RAT, the method
comprising: determining that the device should transition from the first
RAT to the second RAT; in response to determining that the device should
transition, determining that data is present in a reordering queue
implemented by the reordering component; sending the data present in the
reordering queue to a second layer which is higher than the first layer;
and attempting transitioning from the first RAT to the second RAT.