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Number of EVDO carriers per sector in the Chicago market?


briank101

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I'm getting up to speed on all the bits and pieces of the Sprint network after getting my Moto X smartphone about 6 weeks ago. I was trying to find some info on the number of EVDO rev. A carriers per sector at a typical site in the PCS spectrum constrained Chicago market. I guess what I'm trying to find out is the effective EVDO air link capacity available to me in the outer Chicago suburbs. I would find it hard to believe if there is only one EVDO carrier serving the whole area of a sector with only 3.1 Mbps theoretical max to share with everyone in my area.

 

Out where I live, a typical tower serves about a 3 mile radius which I calculate a 120 degree sector would cover the users in a 9.4 square miles area (with the 3 sectors of the tower would cover abaout 28.3 sq miles). Ideally I perhaps could use a spectrum analyzer which I could maybe borrow from work, but if someone here has the scoop, it would be very helpful.  Now if there is 2, 3 or 4 EVDO carriers per sector with the back haul to match, then I suspect there is some breathing room, and my phone perhaps can jump to the carrier that is least utilized, possibly by looking at SNR if I understand correctly.

 

Also would I be correct to state that one 1X Adv carrier and 3 EVDO carriers would fit exactly into 5 MHz of spectrum?

 

I appreciate any feedback as a brand new poster.

Brian

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Not including the acquired USCC PCS spectrum, Sprint has two non adjacent 10 MHz (aka 5 MHz FDD) PCS blocks for CDMA2000 usage in Chicago.  Each one allows for a maximum of three CDMA2000 carriers plus guard bands.  In other words, the limit in Chicago is six CDMA2000 carriers.  Houston is Sprint's only other top 20 market so constrained -- all other top 20 markets have spectrum to support at least seven, at most 11 CDMA2000 carriers.

 

As for the actual number of CDMA2000 carriers deployed and the ratio of CDMA1X to EV-DO carriers, that varies somewhat from site to site.  S4GRU has that data for nearly all markets, but as I recall, Chicago is the most notable one for which we were unable to obtain that info.  So, to discover EV-DO carriers deployed on a particular site/sector, you would need to use an empirical, iterative process.  I describe it in an article that I wrote in 2012, linked below.

 

http://s4gru.com/index.php?/blog/1/entry-318-can-toggling-airplane-mode-actually-improve-your-3g-data-speeds/

 

AJ

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Great information AJ. I think I got to become a subscriber for this info alone, Thanks.....  I've got to try that iterative method you discussed.

 

 

So when the former USCC PCS spectrum becomes available for Sprint use in Chicago (which I think is soon), do you see Sprint adding on a few more EV-DO carriers in the expanded spectrum, or has LTE got its foot in that door already? It's hard to get a feel for what the recent Sprint press release for Chicago, where they "invite Sprint users to retry 3G", really means. Is it just improved back haul supplying the same air link capacity (which BTW is not insignificant), or is it more EV-DO air link capacity since December, or is it more EV-DO capacity once the former USCC spectrum is ready in the coming months?  

 

It would be interesting to see when PC Magazine does its annual "Fastest Mobile Networks" review, if Sprint in Chicago and other markets, tick up a place or two as a result of NV, both in the 3G and 4G ratings.

Edited by briank101
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Regarding use of the USCC spectrum, no one knows for sure.  My gut feeling is that it will be a mix of LTE and EV-DO.  In particular, the contiguity of existing Sprint PCS D block spectrum to the acquired USCC PCS B block spectrum will allow Sprint to drop guard bands between the two and fill it with an EV-DO carrier.  Then, expect a second 5 MHz FDD LTE carrier.

 

I wrote an article on the USCC spectrum deal about a year ago.  You will find more of this kind of discussion in the article and the comments, again linked below.

 

http://s4gru.com/index.php?/blog/1/entry-334-updated-sprint-uscc-spectrum-deal-sprint-gets-20-mhz-broader-in-the-city-of-broad-shoulders/

 

AJ

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  • 2 weeks later...

So when the USCC PCS block B spectrum becomes available in the Chicago market which I understand will give Sprint 40 MHz of spectrum, will Sprint be able to offer 10X10 MHz LTE instead of the current air link capacity constrained 5X5 MHz? 

 

As most devices currently access LTE in the PCS band, LTE experience as far as users are concerned will be their speeds in this band at least in the short to medium term. The way I see it, it doesn't matter if Sprint has the 800 and 2500 MHz LTE spectrum in the pipeline, if Sprint's current slow speed reputation goes down the toilet due to retaining 5X5 MHz LTE speeds on the greater than 90% of the devices that user are using today in the NV "complete" cities such as Chicago.

 

If indeed Sprint is going to change to 10X10 LTE on PCS spectrum, what is the timeline for this?

 

 

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So when the USCC PCS block B spectrum becomes available in the Chicago market which I understand will give Sprint 40 MHz of spectrum, will Sprint be able to offer 10X10 MHz LTE instead of the current air link capacity constrained 5X5 MHz? 

 

As most devices currently access LTE in the PCS band, LTE experience as far as users are concerned will be their speeds in this band at least in the short to medium term. The way I see it, it doesn't matter if Sprint has the 800 and 2500 MHz LTE spectrum in the pipeline, if Sprint's current slow speed reputation goes down the toilet due to retaining 5X5 MHz LTE speeds on the greater than 90% of the devices that user are using today in the NV "complete" cities such as Chicago.

 

If indeed Sprint is going to change to 10X10 LTE on PCS spectrum, what is the timeline for this?

http://s4gru.com/index.php?/topic/5351-number-of-evdo-carriers-per-sector-in-the-chicago-market/?p=266852

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Would two 5X5 LTEs be almost as good as one 10x10?

 

Do two half gallons of orange juice equal one gallon of orange juice?

 

AJ

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If one 10X10 LTE is possible vs two 5X5 LTEs, then I would say to Sprint go for the 10X10 option as on average it gives a higher speed with the same data capacity overall. When a lot of devices are simultaneously accessing the tower, it's then probably a tie during peak timeslots, especially with applications requiring continuous high bandwidth (video). But higher peak speed gets one on and and off the air link quicker for all the non-continuous high bandwidth applications, so the 10X10 should provide for a better user experience a higher % of the time, in my opinion.

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If one 10X10 LTE is possible vs two 5Xs, then I would say to Sprint go for the 10X10 option as on average it gives a higher speed with the same data capacity overall.

 

This has been stated too many times to count.  Numerous Sprint devices over the past two years support only 5 MHz FDD carriers, not 10 MHz FDD carriers.  Sprint will not go the 10 MHz FDD route.  Plus, the acquired USCC spectrum will not be used exclusively for LTE, so a 10 MHz FDD will not be possible.  I feel confident in that assertion.

 

AJ

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In terms of capacity, yes. In terms of speed, no. 

 

This is not completely accurate.  The theoretical speed will not increase above 37.5Mbps per carrier by deploying a second 5MHz LTE carrier, but actual speeds will increase significantly.  Deploying two 5MHz carriers will cause the speeds to go way up from what was being experienced by one carrier.  It immediately doubles capacity.

 

And also with the addition of another LTE 800 5MHz carrier, the site will triple its capacity.  At least for Band 26 device owners.

 

Robert

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In terms of capacity, yes. In terms of speed, no. 

 

Hmm, that is overly simplistic.  See this example.

 

VZW has had a 10 MHz FDD carrier from the beginning, but on an average basis, it has become typically slower than Sprint's 5 MHz FDD carrier.  Loading is the reason.  Now, when Sprint deploys a second 5 MHz FDD carrier, loading per carrier will decrease, thereby increasing average speeds.

 

So, I presume that you are not talking about average speeds but peak speeds.  And, well, peak speeds are basically good for e-penis enlargement.  That is about it.

 

AJ

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Unless Sprint and their vendors re-certify all the devices that only support 5Mhz LTE channels for 10Mhz LTE channels, then we won't see 10Mhz FDD LTE in any Sprint market for quite some time.  As Robert and AJ stated quite well, the only thing that 10Mhz FDD gives you is a higher peak speed, I'm not sure why a mobile device needs greater than 5mb/s continuous throughput.

 

All of this assumes that Sprint has scaled the backhaul up for the extra LTE carriers.

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All of this assumes that Sprint has scaled the backhaul up for the extra LTE carriers.

 

This is the most important point of all.

 

Robert

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As Robert and AJ stated quite well, the only thing that 10Mhz FDD gives you is a higher peak speed, I'm not sure why a mobile device needs greater than 5mb/s continuous throughput.

 

I guess it's the user's minimum throughput speeds that generates the majority of negative publicity. A few 50 kbps LTE users can spread a lot of bad word pretty quickly. If a second 5X5 LTE on the PCS band addresses the min. speed issue at least at the high usage sites, until the number of Spark devices has a chance to reache a level to take the strain off the PCS band, then Sprint has a fighting chance with the overall tri-band LTE strategy (Spark). But if all the bad word of mouth about slow LTE speeds on PCS, because sprint doesn't add LTE capacity there in the near-term, Joe Public will not even consider Spark and assume it is just another Sprint catch phrase, and all the marketing in the world may be too late to save Sprint.

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I guess it's the user's minimum throughput speeds that generates the majority of negative publicity. A few 50 kbps LTE users can spread a lot of bad word pretty quickly. If a second 5X5 LTE on the PCS band addresses the min. speed issue at least at the high usage sites, until the number of Spark devices has a chance to reache a level to take the strain off the PCS band, then Sprint has a fighting chance with the overall tri-band LTE strategy (Spark). But if all the bad word of mouth about slow LTE speeds on PCS, because sprint doesn't add LTE capacity there in the near-term, Joe Public will not even consider Spark and assume it is just another Sprint catch phrase, and all the marketing in the world may be too late to save Sprint.

 

Sprint brought a lot of that on themselves by overselling and under delivering on the entire Network Vision project.  They started selling LTE devices too early and launching LTE markets before a suitable number of sites were completed.  To top it all off, the coverage map on sprint.com is so over generous, it misleads customers into believing what they will experience with ANY sprint device.  This doesn't even bring into account the issues in the markets where the OEM changed and site to site handoff was a hard cut.

 

If all a user cares about is their Peak speed, then have fun over at Verizon or T-Mobile or AT&T.

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They started selling LTE devices too early and launching LTE markets before a suitable number of sites were completed.

 

Absolutely not.

 

In spring/summer 2012, Sprint had to sell variants of the latest devices.  Otherwise, it would have gotten killed by the other big three.  Had the Samsung Galaxy S3 and HTC EVO LTE instead been CDMA2000/WiMAX or even worse -- CDMA2000 only -- do you realize how many subs would have gone apoplectic when they learned a few months later that their market had LTE but their two year contract phones would never be compatible with the new 4G network?

 

AJ

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Absolutely not.

 

In spring/summer 2012, Sprint had to sell variants of the latest devices.  Otherwise, it would have gotten killed by the other big three.  Had the Samsung Galaxy S3 and HTC EVO LTE instead been CDMA2000/WiMAX or even worse -- CDMA2000 only -- do you realize how many subs would have gone apoplectic when they learned a few months later that their market had LTE but their two year contract phones would never be compatible with the new 4G network?

 

AJ

Damned if you do and damned if you don't.  Sprint sold so many WiMax devices to people that never got to use it, then they get sold an LTE device that they might get to use.  Sprint could have easily gone the T-Mobile route and "enabled" LTE on devices once they were ready to launch the service.  I'll concede that top of the line devices were needed, but the marketing needed to be done differently.

 

As for the market launching and coverage map, it's been a debacle, Sprint should have never "launched" and LTE market with less than 40% of the sites online.

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I never really realized how fortunate I am until I read this thread. Sprint has been kind to Chicago.

Especially that it is almost complete nv wise, spark is deployed and 800lte is on the way. In addition, the purchase of the spectrum.
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This is not completely accurate.  The theoretical speed will not increase above 37.5Mbps per carrier by deploying a second 5MHz LTE carrier, but actual speeds will increase significantly.  Deploying two 5MHz carriers will cause the speeds to go way up from what was being experienced by one carrier.  It immediately doubles capacity.

 

And also with the addition of another LTE 800 5MHz carrier, the site will triple its capacity.  At least for Band 26 device owners.

 

Robert

 

That is only true if multi-carrier technology is enabled on the cell site. Otherwise you have to hope that the UE would pick the right carrier to get good performance. As far as I know, only Samsung cell sites have it.

 

In terms of capacity, yes. In terms of speed, no. 

No to both. Multi-carrier (load balancing across multiple independent carriers) provides a linear capacity boost while not providing any bandwidth improvements. Carrier aggregation (bonding multiple independent carriers together) provides slightly less than linear boost to downlink performance and capacity.

 

However, wider carriers provide a noticeably higher than linear boost in downlink and uplink performance (compared to aggregating multiple independent carriers covering the same amount of spectrum), and capacity is experiences a higher than linear boost because the ratio of data subcarriers to overhead substantially increases. This is why wider carriers are preferable to multi-carrier and carrier aggregation.

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That is only true if multi-carrier technology is enabled on the cell site. Otherwise you have to hope that the UE would pick the right carrier to get good performance. As far as I know, only Samsung cell sites have it.

No to both. Multi-carrier (load balancing across multiple independent carriers) provides a linear capacity boost while not providing any bandwidth improvements. Carrier aggregation (bonding multiple independent carriers together) provides slightly less than linear boost to downlink performance and capacity.

However, wider carriers provide a noticeably higher than linear boost in downlink and uplink performance (compared to aggregating multiple independent carriers covering the same amount of spectrum), and capacity is experiences a higher than linear boost because the ratio of data subcarriers to overhead substantially increases. This is why wider carriers are preferable to multi-carrier and carrier aggregation.


With LTE, the network can tell your phone to move to a different carrier so it can balance the load that way. In this way adding another carrier will improve network speeds. Simply moving users from a very congested carrier to a less congested one will improve the speeds for the users. Their THEORHETICAL top speed won't improve, but simply dividing up the load (not through aggregation, just moving some users to the other 5x5 carrier) will improve their real life performance.
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However, wider carriers provide a noticeably higher than linear boost in downlink and uplink performance (compared to aggregating multiple independent carriers covering the same amount of spectrum), and capacity is experiences a higher than linear boost because the ratio of data subcarriers to overhead substantially increases. This is why wider carriers are preferable to multi-carrier and carrier aggregation.

 

That seems anti factual, Neal.  If that were true, then a 10 MHz FDD carrier would be able to provide disproportionately greater peak speeds than could a 5 MHz FDD carrier.  However, that is not the case.  So, I would like to see some evidence to support your assertion.

 

AJ

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Damned if you do and damned if you don't.  Sprint sold so many WiMax devices to people that never got to use it, then they get sold an LTE device that they might get to use.

 

No matter what Sprint chooses, many of you would say that Sprint is just "damned."  If your market never received WiMAX or just a protection site or two, you need to let it go.  That is in the past.  And WiMAX deployment was not under Sprint control.  But we do not need to rehash that issue for the umpteenth time.

 

LTE is the going concern, and I believe part of Sprint's deployment strategy that does not bow down to the holy holy trinity of New York, Los Angeles, and San Francisco is to reassure subs that LTE will not be the same as WiMAX.  LTE is being deployed to both Manhattan, NY and Manhattan, KS -- to subjugate one of magenta's stupid potshots.  Seeing LTE pop up in markets large and small across the whole Sprint network should give subs confidence that LTE is going to be ubiquitous, so their LTE handset adoption will not be in vain.

 

AJ

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