A system includes a packet generator, a preamble generator, and a modulator. The packet generator generates a packet including a preamble for transmission via a sub-1 GHz channel. The preamble generator generates the preamble for the packet. The preamble includes a first signal field and a second signal field. The first signal field and the second signal field conform to a Very High Throughput format specified in a wireless networking standard. The modulator modulates both the first signal field and the second signal field of the preamble using the same modulation scheme in response to the packet being a single user packet. The modulator modulates the first signal field and the second signal field of the preamble using different modulation schemes in response to the packet being a multiuser packet.