  Communication and sensing technology play a significant role in various
aspects of modern society. A seamless combination of the communication and the
sensing systems is desired and have attracted great interests in recent years.
Here, we propose and demonstrate a network architecture that integrating the
downstream quantum access network (DQAN) and vibration sensing in optical
fibers. By encoding the key information of eight users simultaneously on the
sidemode quantum states of a single laser source and successively separating
them by a filter network, we achieve a secure and efficient DQAN with an
average key rate of 1.88*10^4 bits per second over an 80 km single-mode fiber.
Meanwhile, the vibration location with spatial resolution of 120 m, 24 m, and 8
m at vibration frequencies of 100 Hz, 1 kHz, and 10 kHz, respectively, is
implemented with the existing infrastructure of the DQAN system. Our integrated
architecture provides a viable and cost-effective solution for building a
secure quantum communication sensor network, and open the way for expanding the
functionality of quantum communication networks.
