Methods, systems, and devices for wireless communications are described. A device may determine a packet for transmission and determine whether to transmit a reservation signal prior to the transmission of the packet based in part on a condition. The condition may include, but is not limited to, a packet size, or a packet priority, or a combination thereof. According to the determination, the device may refrain from transmitting the reservation signal or allocate resources for the reservation signal from a same resource pool associated with the transmission of the packet or a dedicated resource pool according to a pre-reservation resource pattern.