How to plan PTP 550 in LINKPlanner

The PTP 550 product is based on 802.11ac Wave 2 and operates in the 5.1 to 5.9 GHz bands. This product is a dual channel solution and will support both 1+0 and 2+0 link configurations, which introduces new functionality into LINKPlanner in the unlicensed band.

In frequency bands 5.1 to 5.9 GHz the PTP 550 product is selected as usual from the list of products. The default configuration has a Link Type of 2+0 to enable both radio channels. To plan a link using only one channel set the Link Type to 1+0. The Equipment menu then has the same selection options as other ePMP products.

PTP 550 introduces an 80 MHz bandwidth, which is available under the bandwidth menu option. The 802.11ac also uses different naming for the modulation modes, as well as introducing two 256 QAM modes. The modes are now numbered from MCS 1 (QPSK 0.5) up to MCS 9 (256 QAM 0.83) in either one (Single) or two (Dual) streams. MCS 1 to MCS 7 in 802.11n are the same modulation modes as MCS 1 (Single) to MCS 7 (Single), however the 802.11n modes MCS 9 to MCS 15 are now mapped as MCS 1 (Dual) to MCS 7 (Dual).

To configure a 2+0 link set the Link Type to 2+0 and then select the parameters for Link A and Link B to configure each channel. Link A and Link B can operate in different frequency bands, with different bandwidths and Maximum Mod Modes, but must share the same DL/UL Ratio, Frame Period and Master end. Depending on the bands selected, not all bandwidth options are available, LINKPlanner will guide you on which combinations can be used.


When 2+0 is selected LINKPlanner will change the icon in the navigation menu and add two paths for Link A and Link B.


To access the Configuration at Each End and detailed Performance select either Link A or Link B as required.

The two channels share the same antenna and cable loss (if appropriate), hence the selection of these is the same as normal. When they are changed on either Link A or Link B, the change will be mirrored on to the other path.

The user limits for the Maximum EIRP and Power can be configured independently on each path. It may be preferred if using different bands on each path, which have different regulatory limits, to reduce the power of the band with the higher limit, to give the two paths similar performance.

PTP 550 introduces the ability to set the actual transmit frequency for each path, by choosing the Select … option next to Tx Frequency. This is a very similar functionality to that used for the PTP 820 product, however as the link uses the same frequency in both directions only one channel needs to be selected for each path. If the two channels are operating in the same band, LINKPlanner will automatically limit the selection of the second channel to ensure that it does not overlap with the first channel.


At the individual path level (Link A or Link B) the Performance Summary and Performance Details show the information for that radio channel the same as for the other ePMP products. Note that the Frame Size is a shared parameter for all paths.

The parent path shows a high level summary of the aggregate performance. The detailed performance at the individual modulation mode level is not shown at the aggregate level, due to the fact that different bandwidths and regulations can result in very different availabilities for the throughput. The Min IP Required is a read only value, which is the sum of the two individual path Min IP Required values. Again this is due to the fact that the availability for one data rate on one path can be very different from the availability for even the same data rate on the other path, therefore setting it on the aggregate will not provide a true result.


What is the method of load balancing between the two links? Could it be that one link carried more traffic than the other? How much more?

I found this link: PTP 550 Load Balancing and Throughput Testing.
Its author tries to explain it and gives ways to test it.

I see that you are following up with questions on the product thread, which is the best place to get product specific questions answered rather than on this LINKPlanner thread.


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