System simulator (100, 200, 300, 400, 500) for a test arrangement for testing an electronic device under test (190, 290, 390, 490, 590) in an environment with a plurality of communication partners, wherein the device under test (190, 290, 390, 490, 590) receives signals from different communication partners, the system simulator (100, 200, 300, 400, 500) comprising: at least one communication partner simulator (101, 201, 301, 401, 501) configured to simulate a communication partner of the device under test (190, 290, 390, 490, 590), and a control unit (103, 203, 303, 403, 503) configured to dynamically control at least one communication channel (104, 204, 304, 404, 504) used by the at least one communication partner simulator (101, 201, 301, 401, 501) based on a channel usage schedule (105, 205, 305, 405, 505) of the device under test (190, 290, 390, 490, 590), and a channel information interface configured to communicatively couple the control unit (103, 203, 303, 403, 503) to the device under test (190, 290, 390, 490, 590) to retrieve channel usage information from the device under test (190, 290, 390, 490, 590), wherein the channel information interface comprises a wiretapping interface configured to tap into the communication between a modem of the device under test (190, 290, 390, 490, 590) and transceivers (393, 493) of the device under test (190, 290, 390, 490, 590) to intercept channel configuration commands from the modem to the transceivers (393, 493), wherein the channel usage information is applicable to determine the channel usage schedule (105, 205, 305, 405, 505) of the device under test (190, 290, 390, 490, 590), wherein the channel usage schedule (105, 205, 305, 405, 505) comprises information about a type of the at least one communication channel (104, 204, 304, 404, 504) that the device under test (190, 290, 390, 490, 590) uses and information about the when the device under test (190, 290, 390, 490, 590) uses the respective communication channels at least one communication channel (104, 204, 304, 404, 504), and wherein the at least one communication partner simulator (101, 201, 301, 401, 501) is configured to simulate only communication partners out of a plurality of available potential communication partners that are momentarily required to communication with the device under test (190, 290, 390, 490, 590). at least one communication partner simulator (101, 201, 301, 401, 501) configured to simulate a communication partner of the device under test (190, 290, 390, 490, 590), and a control unit (103, 203, 303, 403, 503) configured to dynamically control at least one communication channel (104, 204, 304, 404, 504) used by the at least one communication partner simulator (101, 201, 301, 401, 501) based on a channel usage schedule (105, 205, 305, 405, 505) of the device under test (190, 290, 390, 490, 590), and a channel information interface configured to communicatively couple the control unit (103, 203, 303, 403, 503) to the device under test (190, 290, 390, 490, 590) to retrieve channel usage information from the device under test (190, 290, 390, 490, 590), wherein the channel information interface comprises a wiretapping interface configured to tap into the communication between a modem of the device under test (190, 290, 390, 490, 590) and transceivers (393, 493) of the device under test (190, 290, 390, 490, 590) to intercept channel configuration commands from the modem to the transceivers (393, 493), wherein the channel usage information is applicable to determine the channel usage schedule (105, 205, 305, 405, 505) of the device under test (190, 290, 390, 490, 590), wherein the channel usage schedule (105, 205, 305, 405, 505) comprises information about a type of the at least one communication channel (104, 204, 304, 404, 504) that the device under test (190, 290, 390, 490, 590) uses and information about the when the device under test (190, 290, 390, 490, 590) uses the respective communication channels at least one communication channel (104, 204, 304, 404, 504), and wherein the at least one communication partner simulator (101, 201, 301, 401, 501) is configured to simulate only communication partners out of a plurality of available potential communication partners that are momentarily required to communication with the device under test (190, 290, 390, 490, 590).