A Generic Software Architecture for PoE Power Sourcing Equipment

Abstract: The IEEE Power over Ethernet (PoE) protocol is currently the most used standard for allowing Power Sourcing Equipment (PSE) to distribute power to Powered Devices (PD) through standard Ethernet cables, permitting devices to be added to a network without needing extra power cables.There exist many PSE manager circuits which can be used to easily distribute power to a handful of PDs, but a problem arises when more are desired, since very few of these circuits can communicate with other circuits, and thus can't coordinate power distribution with each other.The goal of this work was to discover the feature set of some popular PSE managers, discover any real-time requirements they may demand of a host, and to then use this knowledge to create an API which could coordinate multiple PSE managers to handle power distribution.The work was carried out with a study of three PSE managers (PD69200, LTC4291, and TPS23880), as well as study and experimentation of the real-time requirements. After this a series of different architectures were created and evaluated using a combination of analysis, questionnaires, and prototype implementation. The work resulted in a software architecture which allows any number of PSE managers of any model to be used simultaneously in a system, with minimal-to-zero considerations needing to be made for different PSE managers. This allows the system hardware to be designed free of any software considerations, and allows the user to operate the system similarly regardless of the underlying architecture.