PSM parameters

• Periodic TAU (Tracking Area Update)

  • Controls how often the device updates its location with the network
  • Configuration options:

  # Configure TAU in seconds
  CONFIG_LTE_PSM_REQ_RPTAU_SECONDS=7200  # 2 hours (default in prj.conf)
  

• Active Time (RAT)

  • Defines how long the device stays active after a wake-up
  • Configuration options:

  # Configure RAT in seconds
  CONFIG_LTE_PSM_REQ_RAT_SECONDS=6  # 6 seconds (default in prj.conf)
  

Key aspects:

• Device negotiates PSM parameters with the network.
• Helps achieve longer battery life.
• Device remains registered but unreachable during sleep.
• Wakes up periodically based on TAU setting.
• Stays active for the duration specified by RAT.

For more information on power configuration, see the Application power configuration section in the Achieving Low Power guide.