BoR PC 02 (20) 06
The leading innovation and R&D lab for the global cable industry
April 30, 2020
Re: Public consultation on draft BEREC Guidelines on Very High Capacity Networks [“VHCN Guidelines”, BOR (20) 47]
CableLabs, the research and innovation consortium of the global cable communications industry, hereby provides technical input to the above-referenced BEREC public consultation. CableLabs’ membership includes eighteen European cable operators, as well as operators in North America, Asia, and Latin America, representing 180 million subscribers and 500 million individual users in total.1 CableLabs works to develop the future of cable broadband network technologies, which cable operators then deploy to serve customers with ever-increasing levels of performance.2
CableLabs and the cable industry share the European Union’s goal, as expressed in the EECC, that all households have available broadband networks that “are capable of providing at least 100 Mbps, and which are promptly upgradeable to gigabit speeds.”3 Cable has a vision and technology roadmap to not only meet this goal and the performance thresholds set forth in the draft VHCN Guidelines, but to go beyond them in critical respects – a combination of technologies, we refer to as “10G.” The attached white paper provides an overview of the specific technology advancements in both the coaxial and optical portions of hybrid fiber-coaxial (HFC) networks to enable cable operators to move towards the 10G vision of delivering symmetrical 10 Gbps services, network latency of 1 millisecond (ms), and enhanced reliability.
To deliver on the 10G vision, cable operators continue to push fiber deeper into the network and closer to the service location, while at the same time migrating to a Distributed Access Architecture (DAA) that moves functionality from the regional hub or headend to the optical node or other similar remote location, closer to the service location.4 Even without bringing fiber completely to the service location, cable’s HFC networks are capable of delivering services that provide similar network performance to that of both wholly fiber networks and fiber-to-the-building networks, as contemplated by the performance thresholds set forth in Criterion 3 in the draft VHCN Guidelines.5
1 CableLabs, About CableLabs, available at: https://www.cablelabs.com/about-cablelabs. CableLabs members operate in 19 European Union member states, plus Norway and the United Kingdom. 2 The specifications developed by CableLabs, and adopted as standards by the Society of Cable Telecommunications Engineers (SCTE), the European Telecommunications Standards Institute (ETSI), and the International Telecommunication Union (ITU), are utilized by our members in Europe and across the globe to enable market-leading performance and security in the provision of broadband service. 3 Directive (EU) 2018/72 of the European Parliament and the Council establishing the European Electronic Communications Code, OJ L 321/36 of 17 Dec. 2018, Recital 24 [hereinafter “EECC”]. 4 CableLabs, 10G: Enabling Future-Ready Networks 8 (Spring 2020) (attached). 5 EECC Art. 2(2) (defining “very high capacity network” as “either an electronic communications network which consists wholly of optical fibre elements at least up to the distribution point at the serving location, or an electronic
The current and near-future capabilities of HFC networks make clear that cable networks can qualify as VHCN, as detailed below and in the attached white paper:
a. Downlink and Uplink Bandwidth (draft VCHN Criterion 3.a-b)
• DOCSIS® 3.1 Technology:
o Downlink. CableLabs’ DOCSIS 3.1 standard provides for optional features that could support up to 10 Gbps of downstream capacity, and commercially available cable modems and gateways currently support up to 5 Gbps of downstream capacity. With DOCSIS 3.1 technology, cable operators are offering services with 1 Gbps downstream speeds.6
o Uplink. The DOCSIS 3.1 standard supports up to 2 Gbps of upstream capacity and commercially available cable modems and gateways can support up to 1.5 Gbps of upstream capacity. Currently available DOCSIS 3.1 equipment is certainly capable of supporting the 200 Mbps upstream speeds as set forth in the draft VHCN Guidelines.7 However, the specifics of any particular deployed HFC network may limit the ability to fully achieve the capability of the technology, without significant reconfiguration of the network. In particular, the frequency split (e.g., low, medium, or high) used in the network will dictate, to a large degree, the available upstream capacity for uplink data rates.8
• DOCSIS 4.0 Technology: CableLabs released the DOCSIS 4.0 specification in 2019 and just this month released an update to that specification.9 The DOCSIS 4.0 technology builds on operators’ investments in deploying DOCSIS 3.1 technologies and will further increase the performance capabilities of HFC networks. Most notably, DOCSIS 4.0 will provide the capability to offer symmetric, multi-gigabit services over HFC networks. This is enabled through two significant advances: The first is full duplex operation – enabling upstream and
communications network which is capable of delivering, under usual peak-time conditions, similar network performance . . .”). 6 CableLabs, 10G: Enabling Future-Ready Networks 5, 7-8, & 9 (Spring 2020). 7 Id. 8 See, e.g., CableLabs, DOCSIS 3.1 Physical Layer Specification (Version I17, Sept. 17, 2019), Section 7.4.13, https://specification-search.cablelabs.com/CM-SP-PHYv3.1 (describing the allowable frequencies for the cable modem transmitter output, i.e., upstream transmissions). 9 CableLabs, 10G: Enabling Future-Ready Networks 5, 7-8, & 9 (Spring 2020); Doug Jones, On the Path to 10G: CableLabs Publishes DOCSIS® 4.0 Specification, CableLabs (Mar. 26, 2020), https://www.cablelabs.com/on-the-path-to-10g- cablelabs-publishes-docsis-4-0-specification (announcing the completion of the extended spectrum capabilities in the DOCSIS 4.0 specification). CableLabs has recently submitted the DOCSIS 4.0 specification for adoption as an ITU standard. We expect DOCSIS 4.0 to be recognized as an ITU standard in the new future, similar to DOCSIS 3.1. See Recommendation J.224: Fifth-generation transmission systems for interactive cable television services – IP cable modems, ITU (July 29, 2019), https://www.itu.int/rec/T-REC-J.224-201907-I/en (adopting the DOCSIS 3.1 specification as an ITU standard). We expect the timeline for commercially available DOCSIS 4.0 devices to be similar to that of DOCSIS 3.1, with initial field trials typically starting around 18 months after specifications are published.
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downstream transmissions to occur simultaneously in both directions over the same spectrum, and the second is a substantial increase in the available spectrum for downstream operations, up to 1.8 GHz.10
o Downlink. The DOCSIS 4.0 specification includes required features that will provide up to 10 Gbps of downstream capacity, readily enabling multi-gigabit downstream services.
o Uplink. Most strikingly, the requirements of the DOCSIS 4.0 specification will provide up to 6 Gbps of upstream capacity, enabling gigabit and multi-gigabit upstream services.
b. Latency and Its Variation (draft VHCN Criterion 3.e-f): CableLabs and the cable industry have long sought to drive increased performance in terms of reducing network latency and have made significant advances in this area.
• DOCSIS 3.1 AQM: The DOCSIS 3.1 specification introduced a required new feature known as Active Queue Management (AQM) to reduce and better control the amount of time – latency – required for data to move through the cable broadband network.11 With AQM, roundtrip latency over the HFC network was dramatically reduced over what was typically observed in prior generations of DOCSIS technology. With AQM, an HFC (access) network, under load, can provide a typical roundtrip latency of 10 ms.
• DOCSIS 3.1 LLD: In January 2019, Low Latency DOCSIS (LLD) became part of the DOCSIS 3.1 suite of specifications. With LLD, the HFC network can provide an order of magnitude improvement over AQM, reliably achieving 1 ms roundtrip latency performance for latency- sensitive traffic (e.g., video conferencing, gaming, or other real-time applications). Not only does LLD drive down the average latency, but it also significantly reduces the variation in latency.12
c. Resiliency (draft VHCN Criterion 3.g): CableLabs recognizes the importance of highly reliable broadband services and understands that outages or degradations in service, however short, have become unacceptable. To that end, we are focused on driving advancements in HFC network technologies that increase the availability and resiliency of cable broadband services. Two examples of these advancements are:
• Proactive Network Maintenance (PNM): PNM focuses on improving network problem detection across both the fiber and coaxial portions of the HFC network and reducing the time and cost of resolution. This is achieved through an efficient, standardized method of collecting key performance indicators (KPIs) from cable modems, cable modem termination
10 CableLabs, 10G: Enabling Future-Ready Networks 5 & 7 (Spring 2020). 11 Id. at 9; see also Greg White, Active Queue Management in DOCSIS 3.X Cable Modems, Cablelabs (May 2014), https://www.cablelabs.com/wp-content/uploads/2014/06/DOCSIS-AQM_May2014.pdf (detailing AQM performance and operation). 12 CableLabs, 10G: Enabling Future-Ready Networks 9 (Spring 2020). 3 systems, and other network equipment and then leveraging cloud-based predictive algorithms, machine learning, and analytics for finding and solving various network issues before any impairment of the broadband service is observable to the end-user.13
• Profile Management Application (PMA): PMA allows the fine-tuning of subcarrier modulation and the grouping of modems in a dynamic and automated manner to continually optimize the performance of the HFC network in response to changes in the physical characteristics of the network, and potentially, to changes in subscriber usage patterns, such as those triggered by COVID-19.14
d. Error-related parameters (draft VHCN Criterion 3.c-d): In developing HFC network technologies, CableLabs has also sought to minimize the errors in the physical layer transmissions between the Cable Modem Termination System (CMTS) and the cable modem. Specifically, the DOCSIS specifications set a maximum packet error ratio of 10-6 for transmissions in both the downstream and the upstream for both cable modems and cable modem termination systems.15 Additionally, the DOCSIS specifications include a required 32-bit Cyclic Redundancy Check (CRC) that results in near-zero packet error rate delivered to the user.16 It is worth noting the packet error requirements within the DOCSIS technology are designed to minimize packet errors or losses during transmissions between the cable modem and cable modem termination system due to RF noise or interference; however, packet errors or losses may be due to a multitude of causes well beyond the physical medium of transmission, including as part of the normal behavior of the Transmission Control Protocol (TCP), for example.
HFC network technologies have the capabilities to meet the performance thresholds set forth in the draft VHCN Guidelines, and CableLabs and the cable industry continue to advance these capabilities as we seek to deliver on the vision of 10G. Should BEREC have any questions in relation to this submission, please contact Mark Walker ([email protected]), or by telephone at (303) 661-3466.
Respectfully Submitted, /s/ Mark A. Walker Mark A. Walker Director, Technology Policy, CableLabs
13 CableLabs, 10G: Enabling Future-Ready Networks 11 (Spring 2020). 14 Id. at 11. 15 See, e.g., CableLabs, DOCSIS 3.1 Physical Layer Specification (Version I17, Sept. 17, 2019), Sections 7.4.14.2 (CMTS Receiver Error Ratio Performance in AWGN Channel), 7.5.12 (Cable Modem Receiver Capabilities), https://specification- search.cablelabs.com/CM-SP-PHYv3.1. 16 See, e.g., CableLabs, DOCSIS 3.1 MAC and Upper Layer Protocols Interface Specification (Version I20, Apr. 7, 2020), Sections 9.1.2.2 (CM Filtering Rules), 10.6.2 (MAC Layer Error-Handling), https://specification-search.cablelabs.com/CM- SP-MULPIv3.1. 4
ATTACHMENT:
10G: Enabling Future-Ready Networks (Spring 2020)
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