Set-Top Box Using the Sony CXD1959
Introduction
The cable industry is evolving rapidly and cre-
ating a new generation of services to consumers.
Examples of these new services are video-on-
demand and high speed Internet access. The
FCC鈥檚 1996 Telecom Reform Act requires the
cable industry to have the retail availability of the
cable subscriber terminal equipment to assure
competition and availability of set-top-boxes for
the benefit of consumers. CableLab was formed to
create OpenCable specifications that define inter-
faces between Hybrid Fiber Coax (HFC) plant
facilities and OpenCable terminal equipment. The
goal of these specifications is to achieve a high
degree of interoperability across cable systems in
North America.
The FCC also mandated the separation of
security and navigation functions in terminal
equipment by July 2000. In addition, the FCC
requires that cable operators stop deploying set-
top-boxes with integrated security function after
January 2005. One OpenCable specification
(POD-Host) defines the subscriber terminal equip-
ment as consisting of a navigation device (set-top)
and an external module called point-of-deploy-
ment (POD). The set-top- box (STB) consists of
the necessary electronics to transport and convert
broadcast signal from the plant facilities to the
subscriber. An intelligent "host" inside the STB
also communicates with the plant facilities to
direct and steer the services. The POD is a detach-
able device, which could be in the form of a PC
card that plugs into a PCMCIA slot on the STB.
This POD module is a renewable and replaceable
device that addresses the issues of Conditional
Access/Security functions, as well as the signaling
functions. One of the purposes of the POD
module is to allow the service providers to
change/upgrade their conditional access and secu-
rity functions as newer technology becomes avail-
able without changing the STB. This allows the
STB to become a more standard device that
can be manufactured by multiple sources,
resulting in competition and thus, low-cost STB.
OpenCable architecture (www.opencable.com).
Set-Top Box
Transport
Stream
Demux
MPEG-2
Dolby AC3
AV
Decoder
Cable
e
Tuner
DEMOD
NTSC/
PAL
Audio
DAC
TV
OOB
I/F
Decryption
Host
碌C
OOB
Descrambler
Encryption
POD
Figure 1. Subscriber Terminal Equipment (Set-top Box)
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漏Copyright 2001, Sony Electronics Inc. All rights reserved.
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