The described technology is generally directed towards sharing a radio by multiple subscriber identities at a device. A time division multiplexing pattern at the device radio gives primary radio use to a first subscriber identity, while also providing time windows for radio use to a second subscriber identity. In response to a communication by the second subscriber identity, the time division multiplexing pattern can be changed to give the primary radio use to the second subscriber identity. Also, a radio resource control protocol can designate appropriate states for the different subscriber identities, designating the subscriber identity with primary radio use as connected, while the other subscriber identity is designated as inactive or idle.