SFP-RF: Interface Specifications for an RF-Modulated Small Form Factor Pluggable Optical Model
The standardization and deployment of optical interfaces for headend equipment offer cost and power savings to MSOs. However, implementing optical interfaces in these devices presents significant technical challenges, since the lack of standardization may result in too many combinations of interfaces to support effectively in a headend device (power, wavelengths, cards, etc.).
Because of this challenge, the following specification proposes a standard for the interfaces between a downstream laser transmitter module and its host. The module is based on the [SFF-8431], but the input will consist of RF-modulated signals that will be amplitude modulated onto an optical carrier. For the purpose of this specification, this module is referred to as SFP-RF. This SFP-RF optical transmitter module could be integrated into headend equipment, such as a Converged Cable Access Platform (CCAP), a Cable Modem Termination System (CMTS), an Edge QAM, or a forward optical transmitter shelf, reducing the need for devices dedicated to forward lasers. The SFP-RF optical transmitter module will function as a downstream laser for the output of cable edge devices. The primary difference between the SFP-RF optical transmitter module and the XFP-RF optical transmitter module is the size of the module and the link lengths supported.
This standard will focus on the communications, electrical, and mechanical interfaces for the SFP-RF optical transmitter module. Unless otherwise noted, requirements held within this standard apply both to the transmitter module and its host.