News | 14.04.2021

Pioneering project for distributed network architectures

Traditional, centralised HFC DOCSIS network architectures cannot meet future demands for service quality, efficiency and flexibility. Therefore, a sustainable further development towards distributed network architectures and ultimately a virtualisation of the networks is inevitable for cable network operators. Broadband Networks long-time customer Groupe SEIC-Télédis chooses RPHY and equips its cable network for the future. 

The remote PHY systems from Casa Systems therefore offer the optimal complement for our customer Groupe SEIC-Télédis, as they already rely on CMTS/CCAP systems from Casa Systems. The extension allows our customer to smoothly develop their network into a distributed access solution that is managed in the same way as the current CMTS/CCAP. The devices, in fact, support all current CMTS/CCAP services and do not require anyadditional customisation.

"We knew that a 1:1 replacement of our old nodes as part of life cycle management would not be sufficient to meet our customers' future expectations of our network and associated service delivery. That is why we have chosen RPHY from Casa Systems. This will enable us not only to reduce our operational costs in the future, but also to increase our service quality and take the first steps towards network virtualisation," says Joël Duc, Head of Telecom at Groupe SEIC-Télédis. 

Different technological approaches with the same goal

With distributed network architectures, so-called Distributed Access Architectures (DAA), customer-oriented functionalities are moved into the supply area via fibre optics. Management functionalities, however, remain centralised and thus allow an efficient operation of the entire network infrastructure.

There are two technologies for the development of DOCSIS networks based on distributed architectures:  

  • Distributed CCAP (D-CCAP), also called Remote MAC-PHY
  • Remote PHY (RPHY)

In the case of D-CCAP, no central CMTS/CCAP system is required, as the systems are distributed in the coverage area. In the case of RPHY, the PHY part is distributed in the coverage area, but the MAC part remains central. 

Both approaches allow a shorter distance between PHY and the customer and increase the flexibility of the provider due to a simplified network architecture. In addition, higher speeds can be offered with simultaneously reduced latency and the quality of service (SNR) can be sustainably increased.