Is there any decrease in radio sensitivity when you activate Enhanced Privacy?

[Q] Is there any decrease in radio sensitivity when you activate Enhanced Privacy in a DP4801e/DM4601e radio, and somehow related, is there any delay in accessing the repeater if RAS is active? By any delay I am referring to a delay that can have an impact on the end user.

[A] Enhanced Privacy and RAS have no impact on receiver sensitivity.

Enhanced Privacy uses multiple keys and a random number to ensure that the payload is different for each burst and superframe of a voice transmission. This requires transporting cryptographic parameters (i.e. Key Identifier, Initialization Vector) with the voice or data. An encrypted voice message requires an additional header and replaces some of the least important bits of the voice payload with the Initialization Vector.

This additional header increases the system access time by around 11ms when polite channel access is used.

Although barely noticeable, the replacement of payload bits does reduce voice quality by around 0,001 PESQ. There is no impact on delay (latency) since no changes are made to the burst structure or ethernet frames.

As mentioned, this reduction of voice quality is hardly noticeable but might explain why someone may think the sensitivity is reduced. The 11ms additional system access time might be noticeable when doing a side-by-side comparison between a clear channel and channel with privacy but the impact to voice communications is so small it cannot be practically measured.