Grass Valley DHP v.1.1 - Manual (Page 13)

5
DHP
Reference Manual
This is only one of a few dozen DHP scenarios. Other scenarios involve MADI inputs and outputs
and AES inputs and outputs. See
Examples on page 24 for a discussion of DHP scenarios.
Preliminary DHP Analysis
In the analysis of your system, you should determine the number of inputs and outputs of each
type:
Fig. 1-2: DHP Links
This evaluation includes the number of standard inputs and standard outputs, the number of
hybrid inputs and outputs, and the number of AES inputs and outputs.
If your router is to perform DHP, you will also need the size of the DHP pool (or DHP “core”), i.e,
the number of DHP links required by your router. This number might be difficult to determine.
Keep in mind that the DHP links are dedicated disembedders and re-embedders and are not to
be considered inputs and outputs. There are several factors to consider.
These are two of the factors:
1 The number of DHP paths that can be in use simultaneously.
2 The number of ports required for each path.
As stated earlier, and illustrated in Figure 1-1, a certain number of hybrid ports and a certain
number of additional standard ports are required for each DHP path.
Potentially, 16 sources could each provide a single audio channel to an output. This would be
considered an extreme and unusual case. If all 16 audio channels come from a single source,
DHP is not used for that route. Thus, the minimum number of sources for DHP is 2 and the
maximum is 16. The number of destinations for DHP is always 1.
You need to determine the average number of ports among all the DHP paths in use simulta-
neously. The average is, of course, somewhere between 2 and 16, probably very close to 2.
Thus, letting ‘A’ be the average number of sources, and ‘N’ be the number of simultaneous DHP
paths,
Disembedder ports = A × N
Embedder ports = N
Additional standard input ports = N
Additional standard output ports = A × N
Note that DHP is used for disembedding and re-embedding audio. Therefore the hybrid cards
that constitute the DHP core must be one of these:
NV8500 Router
Standard Video
(with or without
embedded audio)
AES
Hybrid
Standard Video In Standard Video Out
AES In AES Out
Hybrid In Hybrid Out
DHP LinksDHP Links
External cabling is required
for every DHP path.