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authenticate the user terminal, and provides traffic encryption of unicast and
multicast communications:
• IPSEC can be used to secure signaling between the different entities;
• Client provisioning and authentication methods are already defined for Voice
over IP, and can be extended to multimedia applications in general.
• In the case of a centralized architecture, the operator can extend the current
Conditional Access paradigms to the cable IP environment (bidirectional media,
distributed storage).
4 Conclusion
The Hybrid Fiber Coaxial technology has some inherent advantage over competitive
architectures (XDSL, FTTH), like its scalability and capability to support
simultaneously broadcast, multicast and unicast services. Both the centralized and
decentralized architecture solutions are possible to support future very high bit rate
access; a priori the decentralized digital FTTC solution is the most scalable, but the
mentioned technological challenges have to be solved to make the solution affordable.
Multicarrier techniques associated with capacity approaching error codes appear to be
an attractive candidate solution to optimize the plant capacity, and should be
investigated for the next generation of layer 1 and layer 2 standards.
Significant work is still needed to define a unique architecture for voice, data and
video; however the examples detailed in the paper show that the Packet cable
multimedia architecture is suitable to build a complete system; moreover many
elements coming from the Packet cable architecture can be leveraged to define this
common infrastructure.
References
1. Data-over-cable service interface specifications, available at:
http://www.cablemodem.com.
2. PacketCable 1.0 Architecture Framework Technical Report, available:
http://www.PacketCable.com.
3. Point J. C. « Very high bit rate access on HFC: Requirements and alternatives”,
proceedings of Western Cable Show conferences, dec. 2002.
4. J. Vandenbruaene, E. Claus, L. Martens, B. Merchie, J. Haspeslagh, P. Gabriel "Ingress
and impulse noise measurements on hybrid fiber-coax (HFC) networks", Communications
Cables and Related Technologies, 1998, pp. 425-431
5. Moeyaert V. et al. (1999), Physical layer characterization of hybrid fibre coax (HFC)
networks, Annals of telecommunications, vol. 54, n° 5-6, May-June 1999
6. IST EMBRACE project deliverables, available at : http://www.telenor.no/embrace
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