Techniques for supporting concurrent deployment of 2-millisecond and 10-millisecond TTI for E-DCH transmissions in CELL_FACH state and Idle Mode are disclosed. One example method comprises receiving a (310) transport block from a mobile terminal, wherein said transport block is transmitted using either a 10-millisecond or 2-millisecond TTI, and sending (320), to an RNC, an indication of whether data carried by the transport block was transmitted using the 10-millisecond TTI or the 2-millisecond TTI. In some embodiments, the indication is sent in a user plane frame sent over a base-station-to-RNC interface. A spare bit in an uplink data frame sent to the RNC may be used, for example.