By: Chris Bastian, Curtis Knittle
Cable access networks are evolving rapidly to meet current and future connectivity needs. As late as the 1990s, a cable network was only providing customers with video entertainment. Today, the wired network provides fundamental connectivity to support a plethora of services including working from home, distance learning, telehealth services and, yes, it remains the primary form of transportation for entertainment. video. The pandemic has only increased the need to scale quickly, reliably and securely for connectivity to stay well ahead of the demand for these different classes of service. Cable networks around the world have excelled at this daunting task.
Cable network operators have never shied away from investing in their networks to stay ahead of the service demand curve. According to NCTA, U.S. operators have invested more than $ 290 billion in infrastructure and networks over the past two decades, $ 17 billion in 2020 alone.
As a major step in this investment continuum, NCTA and CableLabs announced the 10G platform at the Consumer Electronics Show 2019. While speed is still a central ‘pillar’ of this platform, latency, security and reliability are also fundamental pillars.
In 2021, CableLabs and SCTE merged, creating an ecosystem that offers research and development, interoperability testing, standardization, training, certification, 67 geographic chapters and an international technical exhibition, all dedicated to the pursuit of technological goals of the cable industry.
To achieve 10G goals, CableLabs and SCTE manage a large portfolio of technology projects. This article provides only a sample of these projects.
DAA moves the physical layer (aka PHY layer), as well as the Media Access Control (MAC) layer in some variations, out of the hub site and into the fiber access node. With the PHY layer (or MAC and PHY layers) moved within the node, fiber connections shift from analog optical technology to digital optical technology, taking advantage of the ubiquitous IP / Ethernet optical transport between the hub and the knot. As the PHY layer is closer to the customer’s home, operators can take advantage of the lower signal-to-noise ratio to deliver higher modulation efficiency, more capacity, overall faster service levels, and improved network performance. .
For operators, large rack units (RUs) are freed up at the hub site, reducing space, power and HVAC costs. Additionally, operational expenses associated with alignment and maintenance are reduced, while network visibility is enhanced with intelligence from remote devices.
The Generic Access Platform (GAP) is a key part of a DAA solution. GAP is a next-generation modular access node that standardizes the physical, thermal, mechanical and electrical interfaces of internal components of a node enclosure.
It is not uncommon for large network operators to manage the supply chain of more than 40 different node boxes and their associated cards in their network. The supply chain includes the initial sourcing of parts, keeping sufficient quantities in their warehouses and trucks, and training technicians to work with all of these variations. For the most part, none of these boxes, transmitters, receivers, amplifiers, and power supplies are interchangeable. Standardizing the node enclosure eliminates this logistical headache. It also allows equipment suppliers to focus on innovation and the development of specific modules in the enclosure. In addition to providing operational efficiency by standardizing the node enclosure, GAP will also support mobility by including LTE and 5G wireless modules. (see figure 1 on the next page)
SCTE recently published two GAP standards: SCTE 273-1 describes the specifications of the GAP box, while SCTE 273-2 details the requirements for interchangeable modules within this GAP box. Use cases envisioned for GAP include wired access, fiber optic access, wireless access, multi-access edge computing, and future applications.
The DOCSIS 4.0 specifications define the requirements for a sixth generation of the broadband solution for hybrid coaxial fiber (HFC) networks. Two modes of operation are defined, each capable of delivering approximately 10 Gbps downstream and 6 Gbps upstream. The DOCSIS full duplex (FDX) mode of operation uses echo cancellation technology to transmit simultaneously in the upstream and downstream directions in the same spectral region. In essence, FDX DOCSIS increases the upstream spectral region from 42 MHz to 684 MHz.