A method performed by a mobile device, the mobile device able to communicate using either of a first transmission time interval, TTI, and a second TTI, at least, the method comprising: receiving, from a network, an indication to enable the first TTI which is a shorter TTI than the second TTI; and switching from monitoring for data transmission scheduling assignments under the control of a discontinuous reception, DRX, configuration associated with the second TTI to monitoring for the data transmission scheduling assignments based on the first TTI; wherein the first TTI is associated with a first DRX configuration, and the second TTI is associated with a second DRX configuration, wherein the first and second DRX configurations comprise different DRX parameters; the method further comprising: enabling the first DRX configuration using the associated DRX parameters to control monitoring for the data transmission scheduling assignments based on the first TTI; wherein the first DRX configuration provides a longer active time for monitoring for the data transmission scheduling assignments than the second DRX configuration; wherein the DRX parameters for the first DRX configuration comprises a first on-duration timer value, and the DRX parameters for the second DRX configuration comprises a second on-duration timer value, wherein the longer active time is due at least in part to the first on-duration timer value being larger than the second on-duration timer value. receiving, from a network, an indication to enable the first TTI which is a shorter TTI than the second TTI; and switching from monitoring for data transmission scheduling assignments under the control of a discontinuous reception, DRX, configuration associated with the second TTI to monitoring for the data transmission scheduling assignments based on the first TTI; wherein the first TTI is associated with a first DRX configuration, and the second TTI is associated with a second DRX configuration, wherein the first and second DRX configurations comprise different DRX parameters; the method further comprising: enabling the first DRX configuration using the associated DRX parameters to control monitoring for the data transmission scheduling assignments based on the first TTI; wherein the first DRX configuration provides a longer active time for monitoring for the data transmission scheduling assignments than the second DRX configuration; wherein the DRX parameters for the first DRX configuration comprises a first on-duration timer value, and the DRX parameters for the second DRX configuration comprises a second on-duration timer value, wherein the longer active time is due at least in part to the first on-duration timer value being larger than the second on-duration timer value. enabling the first DRX configuration using the associated DRX parameters to control monitoring for the data transmission scheduling assignments based on the first TTI; wherein the first DRX configuration provides a longer active time for monitoring for the data transmission scheduling assignments than the second DRX configuration; wherein the DRX parameters for the first DRX configuration comprises a first on-duration timer value, and the DRX parameters for the second DRX configuration comprises a second on-duration timer value, wherein the longer active time is due at least in part to the first on-duration timer value being larger than the second on-duration timer value.