The cable industry, including access networks and operation support systems, is gaining momentum toward the inevitable network disaggregation. The adoption of modern approaches such as Software-Defined Networking (SDN) and Network Function Virtualization (NFV) results in a high degree of programmable network components, which is essential for the migration to Distributed Access Architecture (DAA).
Let’s start from the beginning – shift from Centralized Access Architecture to Distributed Access Architecture
While Hybrid Fiber Coax (HFC) has been around for over 20 years, most current cable networks rely on Centralized Access Architecture (CAA), where the access network involves a combination of coaxial RF and analog optical solutions. whereas the core network consists of CMTS and EQAM equipment. MSOs who followed CCA, until recently seen as a blessing, are now forced to keep pace with growing demand, continuing to find ways to enhance the service delivery network more quickly and cost efficiently drive the path to 10G technology and technology convergence.
MSOs are turning their attention toward Fiber Deep and Distributed Access Architecture (DAA) for their infrastructure. They require a robust technology solution that will not only save space and reduce power consumption but also meet rising customer demand and drive new revenue opportunities in the future.
Drivers of Distributed Access Architecture
- Increased number of 10G+ endpoints in the network (Nodes, Wireless, EPON)
- Increasing residential bandwidth and latency demands
- Better utilization of Fiber Optic network
- Headend and hub physical space and power limitations
- Energy efficiency, CapEx and OpEx targets
- Analog laser distance, CNR, and bandwidth limitations
From Centralized Access Architecture to Distributed Access Architecture
Today’s hybrid fiber coaxial networks can be described as active with no intelligent processing happening in the outside plant. This kind of architecture has served MSOs very well. However, the time has come when the possibility of making a smart network is now a reality. Contemporary HFC architecture performs all the processing in a central headend, and then it goes out through fiber optic cables into the node in the plant and then on to the subscribers’ homes. Distributed Access Architecture (DAA) is an evolutionary approach to transform the cable industry’s access infrastructure by decentralizing and virtualizing headend and network functions.
There are two main approaches of DAA: Remote PHY and Remote MACPHY. The difference between the two variants is based on which CCAP functions get moved to the node:
- in RPHY, only the DOCSIS PHY layer is moved to the fiber node.
- in RMACPHY, both the DOCSIS MAC and PHY layers are moved to the fiber node.
Remote PHY
Distributed architecture based on the Remote PHY technology transfers the DOCSIS PHY layer to the digital optical node, converting analogue optical connections between the headend and the node into digital connections. The big advantage of this approach is the much higher infrastructure performance. Leaving the MAC layer inside the headend allows for easier control and scaling.
It provides a number of benefits for the HFC infrastructure. The introduction of digital optical connections allows operators to use solutions that are more cost-effective and have an established position in the industry. What is more, by using a wider spectrum and improving the connection’s noise parameters, it increases data processing capabilities.
Remote MAC-PHY
Remote MAC-PHY focuses on pushing more of the smart functions to the access node, closer to homes at the edge of the HFC network. Shifting the MAC from the headend or hub makes a CCAP-core redundant. What remains are only routing, switching, and controller functions – a cloud-ready infrastructure. places the MACPHY access layer functions in the access node. In this approach, apart from the benefits of digital fiber, MSOs can free up a vast amount of room in the headend. RMACPHY supports the deployment of full duplex DOCSIS, which will enable symmetric multi-Gigabit upstream and downstream services over existing fiber coax plants. MSOs will also benefit from replacing analog optics with cost-efficient 10G Ethernet transport. And what is most important: MAC processing in the node is reducing the overall service latency. All of this will significantly enhance the network and service performance. However, distributing both the MAC and the PHY access layer functions requires a bit more computing power to secure.
So what is OpenDAA?
The term OpenDAA was coined by Falcon V Systems to put increased emphasis on multi-vendor cooperation in the MSOs network to deploy RPDs, CCAP Cores, RMDs or MAC Managers from different vendors. Since the very beginning, our company has been a catalyst for driving openness and virtualization for the next-gen broadband, focused on a highly interoperable product portfolio.
That is how the initial idea of building an interoperable environment for multi-vendors transformed into OpenDAA (Distributed Access Architecture) – a modular ecosystem targeted at Communication Service Providers (CSP). It allows the CSP to decentralize and virtualize the Headend and Network functions. OpenDAA enables the CSPs to deliver all types of services by utilizing multiple access technologies such as Remote PHY, Remote MACPHY, xPON and Wireless technologies.
Main Goals of OpenDAA are to provide:
- Easier management by enabling AUTOMATION of configuration processes – using Open and standardized DATA models for southbound and northbound interaction with elements of the cable system. Allowing automation such as robotic process automation/ML to reduce costly human interaction for management operations, allowing the DOCSIS platform to act as Infrastructure as a Code. Controlling or Lowering OPEX.
- Continuous Testing to manage the complexity of system/multi-vendors by constant system interoperability, service and system testing. All of this makes it possible to choose different technology stacks and access products that speed up delivering new value streams. This, in turn, controls and/or reduces OPEX or/and new ARPU source
- Disaggregation, which makes it possible to split up monolithic network components and functions of the HFC/PON networks, which potentially leads to commoditization of the hardware and software components responsible for the virtualization of the network functionalities. Disaggregation will accelerate the launch of new value-added services, ease network operations, and further enhance standardization of the DOCSIS systems.
The innovation that Falcon V Systems brings to the industry lies in how Multiple System Operators will deliver products to their next-gen networks using Continuous Integration (CI) and the Continuous Delivery approach. We are developing a broad portfolio of separate software stacks/products that aim to reduce the delivery cycle of new features and the testing cycle for software solutions such as MAC Manager, PAG, OSS/BSS and hardware solutions such us Remote-MAC Device (RMD), enabling real cloud-native agility in cable environments.