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DC900X INSTALLER’S MANUAL (501-3434310) RELEASE 30th Oct. 2009
BACKGROUND TO HOME CONTENT SHARING
TM
Network-Attached Storage
The DC900X Home Content Sharing (HCS) server is connected into a home network. It serves as a single network-attached storage (NAS) device for
shows (content) that can be recorded by up to three “client” set-tops at different locations in the home. These set-tops do not have their own DVR
capability – instead they all share the hard disk in the NAS.
MoCA networks
MoCA (Multimedia over Coaxial Alliance) is a method of sending extra signals over the existing coaxial cables in a home. Whereas the normal in-band
signals for TV shows use frequencies in the range 54 MHz to 860 MHz on the coaxial cable, the MoCA signals use the range 1.15 GHz to 1.5 GHz on the
same cable. The signals do not interfere with each other because of the different frequency ranges. Low-pass filters are used to prevent the MoCA signals
from getting to places where they would cause problems (for example on the main cable network outside the home). Other RF equipment connected to the
coaxial network should be immune to MoCA signals, but, if there are problems, use a low-pass filter between the equipment and splitter.
In the near future, client set-tops will have MoCA capability built into them. Until then, regular non-DVR set-tops, such as the DC700X, can be used as
clients, in conjunction with MoCA dongles (also known as Ethernet-Coax bridges or ECBs). The client set-tops are connected to the MoCA dongles by
Ethernet (Cat5e/Cat6) cables. See the diagrams below and on page 8.
MoCA-Ethernet hybrid network
The diagram below shows the signals in a MoCA-Ethernet hybrid network. One client is connected to the NAS directly by Ethernet cable. Therefore
recordings and play-back to client set-top 3 are done only via the Ethernet cable. Recordings and playback to client set-tops 1 and 2 are done via the
Ethernet cables and the MoCA network on the coaxial cables. The diagram on page 8 is the same network but with typical equipment and cables. The
diagram on page 10 shows a typical in-house scenario.
You cannot use more than three client set-tops in the MoCA-Ethernet hybrid network. If each of the two dual-tuner clients that are using MoCA is making
two recordings at the same time, and, at that same time, a recording is being played back to each set-top, then 95% of the MoCA bandwidth will be used.
Point of entry
Low-pass
filter
MoCA
dongle
Client
set-top 3
Client
set-top 1
MoCA
dongle
Client
set-top 2
Low-pass
filter
HCS server
(NAS)
Coaxial splitter
Coaxial cable
Ethernet cable
Ethernet signals
In-band signals 54 to 860 MHz
MoCA signals 1.15 to 1.5 GHz
Splits the cable input to the various
devices on the MoCA network.
In-band signals to NAS are for
software upgrades only.
MoCA signals to NAS are for
recording and play-back for
client set-tops 1 and 2.
Prevents MoCA signals getting onto
the cable network outside the home.
In-band signals to all three
clients are for live TV shows.
Ethernet signals to NAS are
for recording and play-back
for client set-top 3.
Ethernet signals to the MoCA dongles
are for recording and play-back for client
set-tops 1 and 2.
MoCA dongles (Ethernet-Coax bridges)
also contain a low-pass filter to prevent
MoCA signals reaching client set-tops
1 and 2.
Prevents MoCA signals reaching client set-top 3.