There are provided an apparatus, a method and a system, at a first node, and the apparatus comprises: a transmitter operative to transmit sidelink signals to a second node; and a controller operative to determine whether to use an exceptional resource pool based on at least one of a first condition and a second condition, for the transmitter to transmit sidelink signals, wherein the first condition includes that a first channel busy ratio measured during a first congestion control operation regarding a current resource pool is higher than a first threshold, and the second condition includes that at least one packet is determined to be dropped during the first congestion control operation.