PMP 450 Ask the Experts May 13

The PMP 450 development team will answer any questions you have in the next Ask the Experts session. Find out how to improve network performance and share ideas with network operators aaround the world.

Participating is easy. Just login and join this thread at any or all of the following times on Wednesday, May 13th:

  • 8 – 9 AM CDT
  • 1 – 2 PM CDT
  • 9 – 10 PM CDT

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We look forward to the discussion and meeting with you. Add the sessions to your outlook calendar by clicking on the attachments below:

Can you talk about the PMP450 900mhz please?

We will be sure to do so. What specific questions do you have?

Questions about PMP450 900MHz

1)  What will the AP and SM total throughput be?

2)  What is the suggested upgrade plan (co-exist with PMP100 gear???)

3)  Any chance it can be backward compatible with PMP100 (450 was touted to do that when first announced)

~ And last but not least ~

4)  Is Q4 avability still possible?

1 Like

What happened with the 3GHz 450 SMs and when can we realistically expect more back in the channel?

Jeff


@David Hannum wrote:

Questions about PMP450 900MHz

1)  What will the AP and SM total throughput be?

2)  What is the suggested upgrade plan (co-exist with PMP100 gear???)

3)  Any chance it can be backward compatible with PMP100 (450 was touted to do that when first announced)

~ And last but not least ~

4)  Is Q4 avability still possible?


1) First release of 900 MHz will support 5, 7 and 10 MHz channel bandwidths that will have the same throughput of other PMP 450 systems. If you have clean spectrum in a 10 MHz channel, you can get more than 50 Mbps.

2) We will publish a migration plan prior to launch.

3) As stated, we are not planning compatibility with PMP 100, but "co-location" via synchronization will be capable, and necessary for effective migration.

4) Absolutely, the launch is planned for Q4 of this year!


@test123 wrote:

Can you talk about the PMP450 900mhz please?


We will be sure to do so. What specific PMP 450 900 MHz questions do you have?


@Convergence AMG wrote:

What happened with the 3GHz 450 SMs and when can we realistically expect more back in the channel?

Jeff


We have a backlog of supply here because of increased demand.  It is definitely being hounded with huge effort, and we should catch up to orders within a few weeks.  Sorry for the delays...



Hi David -

To give more detail on #3:  For PMP100 comptibility, there are a number of reasons that it isn't feasible, and those reasons get even worse on 900MHz.   FSK and OFDM each require some overhead which takes away from the airspace that can be used for data.  Because Canopy is based on SMs requesting bandwidth, data transmisions being scheduled, and guaranteed data delivery, the overhead requirements to allow for that to scale become cumbersome and ultimately take way quite a bit of throughput to achieve channel sharing.

So, that is a bit more detail as to why, but as Jonathan said, PMP100 support is not planned for the 450 900 product.  We definitely understand the reasons why it would be very useful, but at the end of the day, it isn't feasible nor practical as a solution.

There will be some guidance on network migration as there was when the PMP450 came out in the 5.x bands.

1 Like

@CambiumMatt wrote:

@David Hannum wrote:

Questions about PMP450 900MHz

1)  What will the AP and SM total throughput be?

2)  What is the suggested upgrade plan (co-exist with PMP100 gear???)

3)  Any chance it can be backward compatible with PMP100 (450 was touted to do that when first announced)

~ And last but not least ~

4)  Is Q4 avability still possible?


1) First release of 900 MHz will support 5, 7 and 10 MHz channel bandwidths that will have the same throughput of other PMP 450 systems. If you have clean spectrum in a 10 MHz channel, you can get more than 50 Mbps.

2) We will publish a migration plan prior to launch.

3) As stated, we are not planning compatibility with PMP 100, but "co-location" via synchronization will be capable, and necessary for effective migration.

4) Absolutely, the launch is planned for Q4 of this year!

1) First release of 900 MHz is planned to support 5, 7 and 10 MHz channel bandwidths that will have the same throughput of other PMP 450 systems. With 5 ms frame the max throughputs will be at 8X: 5 MHz: 30 Mbps; 7 MHz: 45 Mbps; 10 MHz 60 Mbps. 

With regards to supporting 20 MHz channels in the 900 MHz product, is this something that you could use and take advantage of?  If you had a clean channel, this would mean >100 Mbps of throughput.

How well does the PMP450 work in NLOS situations?

My experience in the past with 5.8ghz PMP100 was that even if you had a decent signal through trees, you could count on that SM to be re-reging frequently.  I'm wondering if the 450 with OFDM is any better at that.


@adammoffett wrote:

How well does the PMP450 work in NLOS situations?

My experience in the past with 5.8ghz PMP100 was that even if you had a decent signal through trees, you could count on that SM to be re-reging frequently.  I'm wondering if the 450 with OFDM is any better at that.


Yes, PMP 450 performs better than PMP 100 in NLOS scenarios. PMP 450 uses OFDM technology, which transmits data in a large number of parallel small subcarriers. This helps in NLOS situations. Also, PMP 450 offers two modes of operation: the dual stream mode (MIMO-B) is used for higher throughput in cleaner channel conditions; the single stream mode (MIMO-A) is used for added robustness in more challenging channel conditions (including NLOS). The radio switches  dynamically from one  to the other in case channel conditions change.

2 Likes

Our PMP 450 experts will return in a few hours, but feel free to post your questions and feedback through the day.

Is there a chance we will see a 3,5GHz PMP450 with more TX-Power for the international market. As wimax is vanishing we've some need for a high power gear for our licensed spectrum. But with current TX Power of PMP450 we cant get enough coverage.

On the PMP 450....  we are attempting to read the value that the SMs are set to as far as 1x/2x/4x/6x/8x using OID

1.3.6.1.4.1.161.19.3.3.2.85.   It returns no such object.  The notes say "Engineering Use Only".   

We can rate the actual connected rate using: 1.3.6.1.4.1.161.19.3.2.2.20.  We use both of these variables in our custom analysis tool.

Is there a way to get the value (setting in the radio for Adaptrate) on PMP 450?  if not today, is is coming?

With the 100 series, platform we can do this without problem.

Paul McCall, PDMNet / Florida Broadband

1 Like

Thanks Matt

Ok thanks.  I want to hammer on the NLOS question a little more because right at the moment it's near and dear to me.

Has the 3.65ghz PMP450 been compared to 3.65ghz WiMax products for NLOS performance, and if so, how did it compare?  Assuming we're using the (current) legal FCC limit of +40dbm EIRP, it seems the 450 should be able to match the output of a wimax BS.  Meanwhile the SM+reflector has 6-7dbi more gain that a typical WiMax CPE.  On the surface, it sounds like the 450 should be better than wimax because we've got the same output from the AP, and more receive gain at the CPE, but I've got wimax (and one LTE) vendors telling me that their product is better for NLOS.

I'm wondering if Cambium has done it's own testing on this topic.

1 Like

@ste wrote:

Is there a chance we will see a 3,5GHz PMP450 with more TX-Power for the international market. As wimax is vanishing we've some need for a high power gear for our licensed spectrum. But with current TX Power of PMP450 we cant get enough coverage.


As we develop new products, we constantly evaluate the market needs surrounding power output, especially with respect to the 3 GHz frequency band.  We hear the need for higher output power in this band, and are working to balance product cost versus maximum output power.  Stay tuned for additional news in this area, and thank you for the product feedback and suggestions.


@adammoffett wrote:

Ok thanks.  I want to hammer on the NLOS question a little more because right at the moment it's near and dear to me.

Has the 3.65ghz PMP450 been compared to 3.65ghz WiMax products for NLOS performance, and if so, how did it compare?  Assuming we're using the (current) legal FCC limit of +40dbm EIRP, it seems the 450 should be able to match the output of a wimax BS.  Meanwhile the SM+reflector has 6-7dbi more gain that a typical WiMax CPE.  On the surface, it sounds like the 450 should be better than wimax because we've got the same output from the AP, and more receive gain at the CPE, but I've got wimax (and one LTE) vendors telling me that their product is better for NLOS.

I'm wondering if Cambium has done it's own testing on this topic.


Sidenote1: We have a WiMAX Product which does 33db/Port with 6 ports.

Sidenote2: This LTE Vendor claims much better modulations at the same SNR than any other product (including PMP450). May be Cambium should do a comparison to see/show if this magic is reality.

1 Like