A user equipment, comprising: a processor configured to determine, in response to detecting a second communication network or a change of a geographical position of the user equipment, that the user equipment is to connect to the second communication network in addition to a first communication network to which the user equipment is currently connected; and a communication interface configured to transmit, in response to the determination that the user equipment is to additionally connect to the second communication network, a first message to the second communication network, while the user equipment is connected to the first communication network, wherein the first message comprises timing restrictions and/or carrier and frequency restrictions for communication between the user equipment and the second communication network to inform the second communication network regarding the timing restrictions and/or carrier and frequency restrictions for communication between the user equipment and the second communication network, wherein the user equipment is further configured to establish, after transmission of the first message, the additional connection to the second communication network while the user equipment is connected to the first communication network, wherein the additional connection to the second communication network is subject to the timing restrictions and/or carrier and frequency restrictions in the first message; wherein the processor is further configured to manage a plurality of states of the user equipment, including a first state and a second state, wherein in the first state the user equipment is connected to the first communication network but not to the second communication network, and wherein in the second state the user equipment is connected to both the first communication network and the second communication network; and wherein the communication interface is configured to transmit a second message intermittently to the second communication network while the user equipment is connected to both the first communication network and the second communication network, wherein the second message comprises one or more additional restrictions for communication between the user equipment and the second communication network. a processor configured to determine, in response to detecting a second communication network or a change of a geographical position of the user equipment, that the user equipment is to connect to the second communication network in addition to a first communication network to which the user equipment is currently connected; and a communication interface configured to transmit, in response to the determination that the user equipment is to additionally connect to the second communication network, a first message to the second communication network, while the user equipment is connected to the first communication network, wherein the first message comprises timing restrictions and/or carrier and frequency restrictions for communication between the user equipment and the second communication network to inform the second communication network regarding the timing restrictions and/or carrier and frequency restrictions for communication between the user equipment and the second communication network, wherein the user equipment is further configured to establish, after transmission of the first message, the additional connection to the second communication network while the user equipment is connected to the first communication network, wherein the additional connection to the second communication network is subject to the timing restrictions and/or carrier and frequency restrictions in the first message; wherein the processor is further configured to manage a plurality of states of the user equipment, including a first state and a second state, wherein in the first state the user equipment is connected to the first communication network but not to the second communication network, and wherein in the second state the user equipment is connected to both the first communication network and the second communication network; and wherein the communication interface is configured to transmit a second message intermittently to the second communication network while the user equipment is connected to both the first communication network and the second communication network, wherein the second message comprises one or more additional restrictions for communication between the user equipment and the second communication network.