The PTP 820C is a dual core device; that is to say, each ODU has two transceivers.
This means with an ODU at each end of the link, you can have two radio links!
These two radio links can be co-polar (sharing the same polarization), cross-polar (one is V, whilst the other is H), or the links can share the same frequency (different polarizations—one V and one H) and use cross polarization interference cancellation (XPIC).
What, then, is a “1+0” PTP 820C link?
What is a “1+1” PTP 820C link?
PTP 820 “1+0”
Let’s start with 1+0.
Create a 1+0 PTP 820C link in LINKPlanner. Check out the BOM. See the words OMT? That’s an Orthogonal Mounted Transducer. This takes signals with two different polarizations and puts them onto a circularly polarized antenna.
This allows you to easily use either the V port or the H port on the PTP 820C.
However, if you want to remotely upgrade your link from 1+0 to 2+0 by enabling the 2nd radio at each end of the link, you need to be careful about the 2nd link’s polarity.
LINKPlanner’s PTP 820C 1+0 link has an OMT, which supports cross-polar and XPIC 2+0 links.
If you intend to remotely upgrade your link from 1+0 to 2+0 co-polar (where both links have the same polarity), you should design the link as a 2+0 Co-Polar (ACCP) link to start with. Check out the BOM. Instead of an OMT, it’s got a splitter. This is the type of mediation device you need for co-polar links.
NOTE: If you plan to upgrade from 1+0 to 2+0 cross-polar or XPIC, using LINKPlanner’s PTP 820C 1+0 option is appropriate. (If you want to find out what additional activation keys you’ll need to remotely upgrade to 2+0 cross-polar or XPIC, plan the link as a 2+0 cross-polar or XPIC link and check out the BOM.)
Next, let’s look at 1+1.
PTP 820C “1+1”
What is 1+1 Hot Standby?
It’s protection. It’s hardware protection.
Create a 1+1 PTP 820C link in LINKPlanner. Check out the BOM. Notice that at each end of the link, there are two ODUs! That’s hardware protection. If one of those ODUs fails, the other one will take over.
Stated differently, even though each PTP 820C ODU has two transceivers, they are not used for protection in a 1+1 configuration.
Stated even differently, there’s no such thing as a PTP 820C 1+1 link with just one ODU at each end of the link.
The 1+0 concept outlined above applies to 1+1 links.
Create a 1+1 PTP 820C link in LINKPlanner. Check out the BOM. See the words OMT? That’s an Orthogonal Mounted Transducer. This takes signals with two different polarizations and puts them onto a circularly polarized antenna.
This allows you to easily use either the V port or the H port on the PTP 820C.
However, if you want to remotely upgrade your link from 1+1 to 2+2 by enabling the 2nd radio at each end of the link, you need to be careful about the 2nd link’s polarity.
LINKPlanner’s PTP 820C 1+1 link has an OMT, which supports cross-polar and XPIC 2+2 links.
If you intend to remotely upgrade your link from 1+1 to 2+2 co-polar (where both links have the same polarity), you should design the link as a 2+2 Co-Polar (ACCP) link to start with. Check out the BOM. Instead of an OMT, it’s got a dual splitter! This is the type of mediation device you need for co-polar links. The two ODUs attach to a dual splitter, and then the 2nd splitter puts those two signals onto the antenna. The final signal has the same polarity as the original signals.
NOTE: If you plan to upgrade from 1+1 to 2+2 cross-polar or XPIC, using LINKPlanner’s PTP 820C 1+1 option is appropriate. (If you want to find out what additional activation keys you’ll need to remotely upgrade to 2+2 cross-polar or XPIC, plan the link as a 2+2 cross-polar or XPIC link and check out the BOM.)
Let’s be careful out there!
Dave