Executive Summary
The Hybrid Fiber Coax (HFC) Outside Plant (OSP) Media Access Control (MAC) Layer Specification is part of the suite of specifications developed by the Hybrid Management Sub-Layer (HMS) subcommittee under the SCTE. The purpose of the HMS specifications is to support the design and implementation of interoperable management systems for evolving HFC cable networks. The HMS Media Access Control (MAC) Layer Specification describes the messaging and protocols implemented at the Data Link Layer (DLL), Layer 2 in the 7-layer ISO-OSI reference model, that support reliable and efficient communications between HMS-compliant transponders interfacing to managed OSP network elements (NEs) and a centralized headend element (HE).
The suite of narrowband transponder specifications includes:
- SCTE 25-1 describes a Physical Layer for a narrowband transponder.
- SCTE 25-2 describes a MAC Layer for a narrowband transponder.
- A narrowband transponder based on LoRaWAN® technology, which is expected to be published soon.
The SCTE also maintains a suite of information models (e.g., SCTE 283) and data models (SCTE 38-1 through SCTE 38-11) for devices which are connected to the coaxial cable network via a transponder.
Additionally, the CableLabs Remote PHY specification [R-OOB] provides information on carrying signals, such as this narrowband transponder, over the Remote PHY architecture.
Scope
This specification describes the MAC layer protocols that must be implemented between all Type 2 and Type 3 compliant OSP HMS transponders on the HFC plant and the controlling equipment in the headend to support bandwidth management and reliable communications. Any exceptions to compliance with this specification will be specifically noted in this document as necessary. Refer to Table 1 for a full definition of the Type Classifications.
Benefits
This document describes the MAC Layer for a narrowband transponder used with devices attaching to a coaxial cable network. This version includes updated information for new channel plans and new technology available to implement a narrowband transponder.
This narrowband transponder will allow devices connected to a coaxial cable network to communicate with users, applications and other resources provided by the network operator. This connection will allow remote configuration, access to telemetry and alarms, and long-term support making the coaxial cable network more reliable by providing proactive information about the state of the device with the transponder.
The impact on the broadband industry will be more reliable networks and higher customer satisfaction.
Intended Audience
The intended audience for this document includes cable operators, suppliers and other parties interested in both cable technology and connected devices.