The present invention provides a computer implemented method, system, and computer program product of optimizing bandwidth of cognitive radios (CRs). In an embodiment, the present invention includes monitoring use of channels of digital wireless spectrum by at least one primary user communications device (PU device), resulting in PU activity data describing the use, using a digital wireless spectrum channel with a lowest usage by the at least one PU device as indicated by the PU activity data, detecting when the at least one PU device begins to use at least one digital wireless spectrum channel, calculating TCP connection data describing a plurality of TCP connections in light of TCP connection parameter data, and performing a network congestion-avoidance algorithm using the calculated TCP connection data, resulting in digital wireless transmission characteristics for at least one of the plurality of TCP connections that are optimized for at least one CR device.