One or more devices determine uplink signal strength for a machine-to-machine (M2M) device using a wireless access network. The one or more devices identify a default uplink transmission mode that requires the M2M device to employ transmission time interval (TTI) bundling, when the uplink signal strength is below a particular threshold, and identify a default uplink transmission mode that requires the M2M device to not employ TTI bundling, when the uplink signal strength is not below the particular threshold. The one or more devices store, in a memory, the default transmission mode for the M2M device. The one or more devices retrieve, from the memory and during a wake-up time window associated with the M2M device, the default transmission mode for the M2M device and construct, for the M2M device, an uplink scheduling grant based on the stored default transmission mode.