I’m assuming the chipsets that go into handsets only implement the standards.

I’m talking about a proprietary chip that could do non-standard fixed wireless 
LTE.

That was the case in WiMAX, you could justify a software/FPGA based 
basestation, but the assumption was that the “ecosystem” would provide 
inexpensive CPE in various flavors, base on the standard.  I’m just assuming 
(dangerous) that LTE is similar.

Now if it’s possible to deviate from the standard in the basestation such that 
the latency is reduced, and standards compliant CPE would still work, that’s a 
different situation.  Like MPEG standards where you can come up with all sorts 
of innovative coding methods that can still be decoded by a standards based 
decoder.

More likely LTE latency in the last mile will be deemed acceptable, IMHO.  As 
long as the tradeoff between modulation and retries can be set so latency 
sensitive traffic doesn’t see latency spikes.


From: Gino Villarini via Af 
Sent: Wednesday, November 05, 2014 8:10 AM
To: mailto:[email protected] 
Subject: Re: [AFMUG] Telrad LTE vs 450 3.65GHZ

You Think there are not high volumes of LTE chipsets 

Gino A. Villarini 
@gvillarini



On Nov 5, 2014, at 10:05 AM, Ken Hohhof via Af <[email protected]> wrote:


  I have always scratched my head over the idea that Ubiquiti and Cambium don’t 
have the volume for custom silicon.  But if it’s true, why would fixed LTE have 
sufficient volume?  Unless there’s a giant service provider planning to deploy 
it, like an AT&T, Verizon, Sprint, DISH, etc. for their fixed wireless service. 
 Or unless there’s some huge volume in the international market, but supposedly 
that’s where the WiMAX market was.  It would have to be high volume plus non 
standard for fixed wireless.  Or someone would have to convince a standards 
based LTE chip maker to roll non standard hooks into their chip so fixed 
wireless could leverage the volumes of mobile wireless.

  Typically the FPGA vendors like Altera have a push-the-button path to ASIC, 
but Cambium evidently doesn’t have the volume to justify that.  Or so they 
claim.  That approach does kind of freeze your feature set though, now the 
software defined part is only what you can change in the CPU firmware, not the 
FPGA design, even bug fixes and performance tweaks.


  From: Rory Conaway via Af 
  Sent: Wednesday, November 05, 2014 7:50 AM
  To: [email protected] 
  Subject: Re: [AFMUG] Telrad LTE vs 450 3.65GHZ

  The general path is either a chipset based CPE based on something like a 
handset chipset (not the best idea since it locks down a lot of things and the 
PHY layer really sucks for high-interference environments), FPGA or other 
hardware based SDR client and then move to a chipset to get the second 
generation cost down once the PHY layer is written the way you want it.  I 
thought White Space vendors were going to pursue that path for example.  LTE is 
a lot harder since there is a lot more work that has to be done on the PHY 
layer.   LTE is the best option but proprietary LTE with various techniques, 
some of which are no-brainers, some of which are going to require serious 
out-the-box ideas, would give LTE the best chance when it moves from rural to 
urban.

   

  Rory 

   

  From: Af [mailto:[email protected]] On Behalf Of Ken Hohhof via Af
  Sent: Wednesday, November 05, 2014 6:44 AM
  To: [email protected]
  Subject: Re: [AFMUG] Telrad LTE vs 450 3.65GHZ

   

  Exactly, can they do proprietary CPE?

   

  From: Jason McKemie via Af 

  Sent: Wednesday, November 05, 2014 12:18 AM

  To: [email protected] 

  Subject: Re: [AFMUG] Telrad LTE vs 450 3.65GHZ

   

  The latency is in the standard, so they would have to deviate from it.  Being 
SDR, I suppose they theoretically could, I just haven't seen it happen yet.  
Presumably the CPE are built around a standards based chipset, so it would 
probably mean an increase in price for those as well.

   

  On Wed, Nov 5, 2014 at 12:08 AM, Rory Conaway via Af <[email protected]> wrote:

  Why do you say the latency would be significantly higher?  That’s 
manufacturer dependent since they aren’t locked to the full cellular PHY.

   

  Rory

   

  From: Af [mailto:[email protected]] On Behalf Of Jason McKemie via Af
  Sent: Tuesday, November 04, 2014 8:55 PM
  To: [email protected]
  Subject: Re: [AFMUG] Telrad LTE vs 450 3.65GHZ

   

  The 450 is going to smoke the Telrad from a latency standpoint.  This is a 
big downside to this gear IMO.  If someone would optimize LTE for use in a 
fixed environment you could possibly get better latency, but I'm not seeing 
that happening.

   

  On Tue, Nov 4, 2014 at 9:40 AM, Matt via Af <[email protected]> wrote:

  Is anyone looking at both these options?  Pros and cons of one vs
  other?  Throughput, Sync, Interference, spectrum efficiency, cost etc?

  What I really wander is can you bond two non adjacent 10MHZ channels
  with Telrad to make a 20MHZ channel?  I know you cannot with 450 and
  it might become very useful down the road.  Right now with 450 and a
  perfect connection on a 20MHZ channel we can do around 80Mbps
  downstream per sector.  With a 10MHZ channel and not so perfect
  connections that is really getting cut back.

  Also, right now we can do ABAB quite easily with 450 gear.  With LTE
  can we do AAAA where spectrum is scarce?

   

   

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