alt=|thumb|319x319px|BPM time signal in waterfall
BPM is the call sign of the official short-wave time signal service of the People's Republic of China, operated by the Chinese Academy of Sciences, broadcasting from CAS's National Time Service Center in Pucheng County, Shaanxi at , roughly 70 km northeast of Lintong, along with NTSC's long-wave time signal BPL on 100 kHz.
BPM is broadcast at 2.5, 5.0, 10.0, and 15.0 MHz, the same frequencies as WWV and WWVH, following the schedule listed below:
{| class="wikitable"
|-
! MHz !! UTC !! CST
|-
| 2.5 || 7:30-1:00 || 15:30-9:00
|-
| 5 || 0:00-24:00 || 0:00-24:00
|-
| 10 || 0:00-24:00 || 0:00-24:00
|-
| 15 || 1:00-9:00 || 9:00-17:00
|}
Transmission format
BPM transmits different signals on a half-hour schedule, modulated with 1 kHz audio tones to provide second and minute ticks:
{|style="text-align:center" class="wikitable"
|+BPM transmission schedule<br />BCD time code on 100 Hz sub-carrier.
|-
| 10 || 40 || 5 || align=left | Carrier (no time code)
|-
| 15 || 45 || 10 || align=left | UTC: 10 ms second ticks, 300 ms minute ticks, in advance by 20 ms.
{|class=wikitable style="text-align:center;"
|+ BPM time code