PMP 450 licensed spectrum webinar

The PMP 450 Solutions in a Lightly Licensed 3.65 GHz Band and 3.5 GHz band webinar replay is now available HERE.

If you have any questions or comments, please post them in this thread.

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Nothing was said about the RF output power when you use a PMP450 in the 3.65ghz liscensed band outside of Amercia?
What is the maximum RF power the PMP450 can output in liscensed band outside the USA where its not capped.

For example in other 3.65ghz manafactures: Avalon Wimax did 10watts, Nokia Wimax does 40watts, Samsung Wimax does 60watts.
Thanks. :)

The maximum EIRP for the PMP 450 at 3.65 GHz is 42 dBm, or just under 20 Watts (25 dBm transmit plus 17 dBi antenna).

Incidentally, this is also the FCC limit for a 20 MHz channel.

I believe that maximum transmit power the 3.XGHz PMP450 AP is capable of, regardless of regulatory area, is 25dBm, or approx.  316mW's. Coupled with an 18dBi sector antenna would put your EIRP around 43dBm, or approx. 19.95 watts.

If you need more power output for licensed 3.65 operations outside the USA, you're going to pay a whole lot more per AP... at that point you're going to be looking into LTE.

Is there any technical reason why its fixed to a  maxium of 25dbm/316mW? :)

My guess is that when Cambium engineered the PMP450 for the 3.X bands there were constraints that limited the amount of TX power they could offer. Some of these constraints I imagine being:

- They kept the same form factor on the both the AP and the SM, although the SM does have a small heat sink. If they increased the TX power further, they may have had to change the form factor of the AP and increase the size of the heat sink, which would have increased costs and changed the manufacturing process. The small heat-sink on the SM's does cost a bit more money, and explains the slight increase in pricing on the SM side.

- They kept the same size/type/wattage power supply on both the AP and the SM's as all the other PMP450 bands, this would limit the maximum TX power.

- While having a product that has additional TX power would help a few 3.X license holders in the US or abroad, it wouldn't help 3.65GHz lite-licensed operators in the FCC/US market, which, one could argue is a bigger target market (at least in the US) and thus the extra power would be a feature that either A) couldn't be used by 3.65/FCC operators but would still cost extra money, or B) would be abused and used to run above EIRP and thus cause headaches with the FCC.

Deviating from any of the above mentioned items would have introduced new form factors, new manufacturing runs, new power supplies, etc,etc,etc... and would have resulted in a different line of products which would have a higher associated price tag and additional sales and support complexity. Cambium is trying to keep the pricing and form factor along with the overall 'PMP450 experience' relatively the same between all PMP450 bands/products.

Anyway, that's my best guess :-)


Questions from PMP 450 Solutions in a Lightly Licensed 3.65 GHz Band and 3.5 GHz band webinar on February 17, 2015:

Foliage Penetration and MIMO

Q: I've heard from one customer that they weren't getting the tree penetration with the PMP 450 that they are getting from the PMP 320.  I heard something at the Animal Farm conference that the latest PMP 450 firmware significantly improved penetration.  Can you please discuss?

A: When the 3.65 GHz PMP 450 originally launched it did not have MIMO-A capability and this did limit some of its ability to penetrate trees. Since the addition of MIMO-A in Software Release 13.2.1(November) we are seeing much better tree penetration comparable to the PMP 320.

Q: Will multiuser MIMO be available from a software update on the PMP 450?

A: We are investigating that possibility.

FCC Regulations

Q: I've been told that we will have access to the 3.5 GHz band with the current PMP 450 once the FCC approves its’ use.  Is that accurate?

A: The FCC is considering changing the band available by opening up 100 MHz below the currently allowed 3.65 GHz band (3650-3700 MHz).  The PMP 450 hardware will support all the way down to 3550 MHz, and will comply with FCC regulations to allow its use when it is released.  It will require a firmware update.  If you'd like to read about the proposal, the FCC NPRM document is here.

Q: If someone goes from PMP320 to PMP450 they don't have to do anything with their licensing, right?

A: An operator does not need to apply for a new license (i.e. the FRN remains the same), but DOES need to update the site information in the FCC database to reflect the change of equipment.

WiMAX Standards

Q: Is the PMP 450 based on the WiMAX platform?

A: The PMP 450 is a protocol built from the ground up by Cambium Networks. It shares many of the strengths of WiMAX (Scheduled MAC Layer, Ability to truly prioritize traffic on the Downlink/Uplink, Scalability, Deterministic Latency) but it is much simpler and more cost effective to deploy. Also, because we are not tied to a standard we can add features (i.e. 40 Mile Range, 256QAM on DL and UL and others) that we would not be able to otherwise.

Q: What are the "isues" with WiMAX? and Why PMP450 is better?

A: WiMax is a standard that seems to have stalled. Most vendors and manufacturers seem to be abandoning WiMax for LTE. PMP450 is better for many reasons. Lower Latency:3-5ms/Larger Channels Sizes:20MHz/No need for an ASN/…All of these advantages are possible because PMP450 is not tied to a standard.

VoIP Services

Q: How do you add VoIP into the capacity tool?

A: VoIP traffic creates very little demand on the system.  That is, voice is not a bandwidth intensive application. Therefore, the PMP 450 would not experience a hit that would reduce throughput by supporting VoIP in addition to regular data traffic.


Q: What is GLONASS?

A: GLONASS is GPS system deployed in Russia.  The ability for the GPS receiver to decode both GPS and GLONASS satellite systems can decrease acquisition time and result in more satellites visible and tracked, leading to higher GPS signal reliability.

Pretty good guesses Eric!