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5G • 5G-Advanced (Rel-18)

Fast Wake-Up Signaling

Inter-Cell and Over-The-Air Fast Wake-Up Signaling for Dormant gNBs

Rapid signaling protocol that wakes sleeping base stations in under 10 ms when sudden user traffic surges exceed the capacity of active towers.

Technical Explanation

When a sleeping base station is needed to handle incoming traffic, wake-up delays must not cause service blockages. Rel-18 standardizes Fast Wake-Up Signaling over the Xn interface and air interface: active umbrella macrocells transmit an instant trigger that powers up sleeping microcells in under 10 milliseconds, ready to accept handovers.

Key Functions

  • Wakes dormant base stations from deep sleep states in under 10 milliseconds
  • Transmits low-latency trigger pulses over the inter-base-station Xn interface
  • Prevents call drops or congestion when traffic surges unexpectedly into dormant zones
  • Coordinates seamless reactivation without disruptive radio channel resets
Specifications
3GPP TR 38.864, TS 38.423 (Rel-18)
Interfaces
Xn-CUu
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