Remote MAC-PHY architecture challenges and opportunities

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.

The technology providers draw MSOs’ attention to several advantages of this approach. It will improve the fidelity of the HFC plant and takes full advantage of the potential of DOCSIS 3.1 technology, which allows higher spectral efficiency. Moreover, it 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. Moreover, it is now certain that the challenge of interoperability also applies to the control interfaces used in the deployment of Remote MAC-PHY architecture. Undoubtedly, the need for standardization is real and an existing technical recommendation is not enough to resolve the MSOs’ interoperability concerns.

Remote MAC-PHY
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.

Benefits:

• Reduces overall service latency
• Brings about significant savings in space and power consumption in the headend or hub
• Better RF utilization – ensures the optimization of any future spectrum expansion
• Increases capacity for higher bandwidth services
• Employs digital optics – reduces costs over existing analog optics
• Supports next-gen services

Challenges:

• Putting MAC/PHY functions in the node creates additional complexity, the heat challenges, the powering challenges
• The standardization of MAC-PHY technology, the approach is in the course of its development
• Today’s products need next-generation silicon solutions in order to lower power consumption

If we can get the MAC and the PHY together with a minimal wattage increase over what we use in a Remote PHY architecture this could be a real game-changer.