802.3bt launched two new PD topologies -- single-signature and dual-signature. Single-signature PDs share the same detection signature, classification signature, and maintain power signature between each pair sets. That is usually used with single load applications. Twin-signature PDs have impartial detection signatures, classification signatures, and maintain energy signatures on every pair set. This is ideal for multi-load applications, like surveillance cameras with a heater. Today, deployments of twin-signature PDs allow for 51W to be delivered on the PD. Nevertheless, newer PD deployments are seemingly to make use of single-signature PDs to avoid wasting on total product price and take advantage of the upper 71W power availability. Will probably be important to determine if the PSE helps single-signature PDs, twin-signature PDs, or both when planning a deployment. A PSE that helps each will not have to be changed as PDs are updated.