As I was researching about WUS(Wake-Up signal)
I have some question that why WUS is only applicable for long DRX cycle not for short DRX cycle?
Thank you
The Wake-Up Signal (WUS) is a mechanism used in 5G networks to wake up a UE from a low-power state (i.e., DRX mode) and signal to the UE that there is data waiting for it to be received.
In 5G, there are two types of DRX modes: short DRX and long DRX. Short DRX has a shorter DRX cycle and is used for scenarios where the UE is expected to receive data frequently. Long DRX has a longer DRX cycle and is used for scenarios where the UE is expected to receive data less frequently.
The Wake-Up Signal is only applicable for long DRX because it takes longer for the UE to wake up from a long DRX cycle than a short DRX cycle. When the UE is in long DRX mode, it typically goes into a deeper sleep state than in short DRX mode, which allows it to conserve more power. However, this deeper sleep state requires more time for the UE to wake up and be ready to receive data.
In order to ensure that the UE is awake and ready to receive data when it is expected to arrive, the gNB sends a Wake-Up Signal before the scheduled arrival time of the data. This gives the UE enough time to wake up, establish a connection with the gNB, and prepare to receive the data. If the UE is in short DRX mode, the Wake-Up Signal is not needed as the UE is already awake and listening for data at regular intervals. Therefore, the Wake-Up Signal is only used for long DRX mode to ensure that the UE is awake and ready to receive data when it arrives.
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