Techniques are described to configure a channel structure for a random-access procedure. For example, a wireless communication method includes communicates, by a first device, a channel structure to a second device, where the channel structure includes a first set of resources reserved for a first message (e.g., a preamble), a second set of resources reserved for a second message (e.g., a payload), or a time duration gap between the first set of resources and the second set of resources. The wireless communication method also includes receiving by the first device the first message and the second message at the configured first and second set of resources, respectively.