 The location, directional pattern and power levels for each of the transmitters would also have to be very carefully chosen, as the ATSC system is subject to very strict limits on the maximum time difference between arrival of multiple versions of the same signal at the receiver.In problem reception areas, significant improvements could be obtained but careful design would be required to operate multiple co-channel transmitters without destructive interference.Further tests run by Telemundo owned-and-operated station WNJU-TV, Ion TV and broadcast tower owner Richland Towers using one main New Jersey transmitter and a Times Square fill-in DTS secondary transmitter in 2007 indicated that, of fifteen test sites for reception of the station in New York city, 40% would obtain a substantial improvement in signal by the addition of a second transmitter to the existing station, while all but one would receive at least the same signal quality as was observed without a distributed transmission system.