A fully digital hybrid solution, Huawei's D-CCAP is a fiber-coaxial technology for Gigabit networks.It enables multi-service operators (MSOs) to plan and build networks so they can get agile and stay competitive over the next five to ten years in the multi-service market.
MSOs deliver TV and communication services on high-quality hybrid fiber-coaxial (HFC) networks using Data Over Cable Service Interface Specification (DOCSIS), a standard that was introduced 20 years ago.
But, with ultra-fast HD and OTT video on Gigabit broadband and consumers expecting more, MSOs need the power to hurdle capability obstacles and reach new opportunities.
Converged IP services: The next big thing
Stable and fast broadband plus Internet apps are now a basic need, and the Internet is disrupting profit models in many industries – each year sees new records for online sales.
MSOs have forged ahead with spectrum and bandwidth improvements over the past decade thanks to Cable Modem Terminating System (CMTS), a centralized resource sharing solution with wired broadband speeds exceeding 100 Mbps. But, CMTS is behind the curve when it comes to Gigabit, and a pricey medium for upgrading bandwidth. Potential bottlenecks include broadband limits on analogue equipment, massive hub equipment space requirements, and high energy use.
IP-based video services are thriving. It is estimated by 2016 over 72 percent of Internet users will adopt OTT video, and giants like Netflix will serve 70 million users. Netflix's OTT video services alone account for more than 30 percent of operators' bandwidth traffic, while HD video content on YouTube streams at an average of 20 Mbps. Clearly, IP-based video and interactive experiences are here to stay.
The triple-network convergence of telecom, TV, and the Internet is also driving network transformation towards a full IP-based model coupled with service and terminal integration.
MSOs have the sharpest edge when it comes to content. They’re pushing strategies for the cross-penetration of different services, seamless connection in multiple scenarios, and personalized services for users in different sectors. Packet-based and best-effort delivery IP technology is the best option for carriers to bear multiple services.
MSOs need to safeguard existing investment when building networks they can smoothly upgrade to IP and transmit both traditional services plus IP video.
Transforming network architecture
HD IP video services like 4K are ready to dive into the mainstream, and so MSOs are building high-bandwidth IP-based converged networks to cope. DOCSIS 3.1 and optical node splitting are the two main solutions to achieve this.
DOCSIS 3.1
Issued by CableLabs in 4Q 2013, the DOCSIS 3.1 standard uses Orthogonal Frequency-Division Multiplexing (OFDM) modulation, allowing multiple sub-carrier signals at the higher frequencies of 204 MHz upstream and 1.2-1.7 GHz downstream.
The standard’s previous incarnation, DOCSIS 3.0, is already widely used in developed countries. Backwards compatible with both DOCSIS 3.0 and 2.0, version 3.1 boosts data transmission efficiency and lowers bandwidth unit costs, enabling MSOs to expand upstream and downstream frequency, and provide Gigabit broadband services. In tandem, equipment vendors are likely to support two upstream and two to four downstream channel capacities to deliver downstream rates of 5 Gbps to 10 Gbps within the next three years.
Despite the welcome jolt to competitiveness, upgrading E2E equipment and reconstructing networks doesn’t come cheap when the following are considered: Coaxial Media Converters (CMC), Cable Modem (CM) terminals, HFC components, and engineering costs. Therefore, selecting the optimum DOCSIS 3.1 transformation solution is a must for competitiveness.
Splitting the node
High-quality HFC networks can potentially create huge value for MSOs that own them.
Optical nodes in HFC networks convert optical signals from the fiber optic network into IRF signals for distribution along coax cable to homes. MSOs can split optical nodes, and move them downwards to cut sharing and increase per user bandwidth. For example, splitting a node for 2,000 homes into four nodes further down the network means each node can supply 500 homes. This process “pushes the fiber deeper” by extending the fiber network closer to the user side.
In HFC networks, Fiber To The Last Amplifier (FTTLA) extends the optical fiber along the line to the last amplifier, close to the subscriber. Most MSOs in developed nations are transforming their networks and positioning one to two amplifiers below each optical node.
Choosing the right optical node equipment to maximally benefit from DOCSIS 3.1 will have a huge bearing on the success of MSOs' HFC network migration strategies.
D-CCAP: Reconstructing HFC
Huawei's Distributed Cable Converged Access Platform (D-CCAP) is designed to deploy Gigabit coaxial services and optimize fiber infrastructure, enabling MSOs to deliver future-ready converged multi-service for the Gigabit era.
It combines DOCSIS 3.1 and optic node splitting solutions, digitizes optical fiber architecture via GPON/10G-PON technology, integrates video services, and shares the same platform as FTTx.
D-CCAP complies with the Remote MAC/PHY system architecture under DOCSIS standards. Here, CMC equipment classifies and forwards data traffic to complete MAC framing on the data-link layer, and modulate and demodulate data on the physical layer. CMCs are deployed closer to the user end – usually on optical nodes – to manage control system protocols for module execution, and configure and manage services. The CMC controller handles services aggregation and routing learning. Moreover, integrating EQAM can distribute video.
The CMC controller uses mature, standard interfaces like GPON, 10G-PON, 40G TWDM-PON, and GE to ensure service reliability between the CMC and CMC controller.
Platform-sharing with FTTx allows MSOs to convert their networks into Fiber-to-the-Home (FTTH), while protecting existing investments and driving up competitiveness.
Minimal construction costs
Lack of hub site space and high energy consumption affect future network upgrades. D-CCAP frees up hub space by digitizing analogue equipment and, in a network covering 30,000 users, there’s no better solution.
Integrating VOD and BC QAM into remote D-CCAP sites further brings out the solution’s advantages. D-CCAP features point-to-multipoint PON architecture, requiring far less optical fibers than traditional point-to-point CMTS/CCAP networks. However, Dense Wavelength Division Multiplexing (DWDM) equipment in CMTS/CCAP networks complicates expansion.
One-step DOCSIS 3.1
While CableLabs' DOCSIS 3.1 standards specify modulation orders of 4K to 16K QAM, most operators cannot currently meet these specifications.
When signals pass through multiple optical-to-electrical or electrical-to-optical converters from the radio frequency interface (RFI) to the optical node, carrier-to-noise ratio (CNR) degradation can be as high as 8dB.
However, very few coaxial broadband users meet the CNR requirement for 4K QAM modulation, which the standards define as a minimum of 41dB. Most lines can only support 1K QAM modulation. Huawei D-CCAP solves this problem with digital fiber optic transmission, which improves CNR and delivers 1Gbps services to 80 percent of users, eight times more than a traditional CCAP.
MSOs are expected to commercially deploy DOCSIS 3.1 in 2016. It takes three to five years to roll out a new standard on a large scale, and MSOs still need to prepare for it. Given the technical and platform limitations of CMTS architecture, upgrading to DOCSIS 3.1 will be expensive and involve several steps, including replacing CCAP platforms and downstream and upstream line cards.
Huawei's comprehensive one-stop solution provides DOSCSIS 3.1 hardware-ready technology and upstream and downstream software capabilities for DOCSIS 3.1 upstream/downstream full service deployment.
Integrated FTTH platform
The trend for full-service operations means more telcos and MSOs are choosing FTTx-compatible FMC strategies. These require platforms that can concurrently support copper Gigabit broadband technologies like DSL, vectoring, and G.fast; Gigabit fiber optic technologies such as GPON, 10G-PON, and 40G TWDM PON; and coaxial Gigabit technologies like DOCSIS 3.1.
Huawei's D-CCAP solution provides three different MSO network construction scenarios on one OLT platform: deploying FTTH through GPON or 10G-PON in new properties, reusing DOCSIS 3.0 cable modems (CMs) to increase speeds over existing coaxial networks, and upgrading CMs to DOCSIS 3.1 so coaxial networks can achieve ultra-broadband capabilities in high-value areas.
The three different scenarios can be delivered on the same OLT platform, ODN network, and CMC equipment. The same management system and OSS can also manage each, helping MSOs build flexible networks and quickly deliver competitive services.
SDN architecture
The software-defined D-CCAP architecture can virtualize the access network, including OLT and CMC, into virtual CCAP equipment. Like a data center, the equipment can automatically acquire and manage IP addresses, and launch automatic configuration and access network service provisioning processes.
Users can trigger network functions and virtual CCAP service provisioning, and customize these on the web portal, allowing the virtual CCAP controller to automatically generate and distribute virtual network resources and service functions as soon as a user goes online.
In the future, Huawei's D-CCAP solution will be programmable and possible to virtualize, accelerating the evolution of networks into open-network API-based Access Network as a Service (ANaaS) networks without needing further configuration. This cuts the need for physical sites and, therefore, investment.
Fully digital D-CCAP for the win
Huawei's D-CCAP is a fully digital Gigabit HFC network solution that provides digitized, distributed network architecture. It increases service bandwidth, frees up hub space, and reduces energy consumption.
D-CCAP delivers one-stop DOCSIS 3.1 commercial capabilities, and includes FTTx solutions on one platform. Leading MSOs have already deployed the solution, including CBN, Vodafone New Zealand, Monaco Telecom, Brazil NET, and Japan’s CNCI. Each uses D-CCAP to provide a rich variety of Gigabit broadband services.
D-CCAP optimizes network planning and construction management so MSOs can control future network construction costs, stay competitive, and keep active in the multi-service market over the next five to ten years.