Appears that two-way comms was required for Beidou-1, not BeiDou-2. See https://space.stackexchange.com/questions/30839/is-two-way-communication-really-required

Appears that two-way comms was required for Beidou-1, not BeiDou-2. See https://space.stackexchange.com/questions/30839/is-two-way-communication-really-required-to-use-beidou-gnss https://space.stackexchange.com/questions/30839/is-two-way-c...