Remote

R-PHY Solutions for the Cable Industry

Remote PHY (R-PHY) is a form of distributed access architecture (DAA) that moves the physical layer to the access network’s edge from the headend or hub. DAA decentralizes cable networks by relocating select functions that have typically resided in the headend or hub to intelligent fiber nodes, closer to the subscriber. The Remote PHY architecture splits the headend’s components between the MAC and PHY layers, allowing the MAC functionality, including bandwidth scheduling and signaling, to stay in the headend, while the PHY functionality is located at the network’s fiber nodes.

A Remote PHY device (RPD) located at the network edge serves as the interface between the core and the fiber node. The RPD converts downstream data transmitted from the core from digital to analog and upstream data from end-users from analog to digital format. The RPD includes QAM modulators for downstream translation and QAM demodulators for upstream traffic. The converged cable access platform core (CCAP core) in the headend or data center can contain a CMTS core element for DOCSIS transmission and an EQAM core for video signals.