In a system and method of adapting an ECSD connection, interruption times and data loss due to a change in the modulation, coding scheme, and number of timeslots of the connection may be minimized or eliminated. The interruption times and data loss may be minimized or eliminated by allocating a peak number of substreams for a given mobile radio connection based on a user requested data rate and/or the number of timeslots used to realize the user requested data rate. Data loss may also be minimized or eliminated by using in-band signaling to signal a change in the modulation, coding scheme, and/or number of timeslots.