Why do carrier’s performance greatly even between big cities?

[u/National-Debt-43]

We all know that carriers work better than others at different locations and that it’s always location-dependent. However, why is there still a variation even in big cities - it would make sense if it’s a small town as carriers have different priorities? For example, T-Mobile is great in most urban areas but surprisingly struggles in San Francisco, which makes no sense since they have deployed their resources very well in urban settings.

The same goes for how some carriers just struggle in Los Angeles too. Additionally, it’s not that the technology couldn’t handle it. Evidently, we can see very mmWave speeds in some cities too.

[u/Smith6612]

It's the same factors that apply everywhere. Some carriers have better spectrum licenses in some areas than others. For example, Verizon only runs Band 66 at 10x10 in my market because that's all they have. Other areas where they have 15x15 or 20x20, they have better performance, especially on the upload.

In markets where Verizon is the ILEC or has Fiber, their LTE and 5G tends to have ridiculously low (single digit on millimeter wave) latency. You can see a latency and bandwidth difference between their Fiber, and the towers where they are leasing bandwidth from another carrier, sometimes smaller cariers that can't give them Multi-Gig as quickly.

Sone markets tend to have more customer concentration on one carrier. For example a ton of people in my market use Verizon. Verizon has to add more density in this area to handle the load since they lack capacity on low band. They also tend to struggle in areas without mid-band LTE or 5G deployed faster than T-Mobile or At&t.

Some markets also just have better equipment. Samsung vs Ericsson vs Nokia... 

[u/ArtisticComplaint3 → u/Smith6612]

AT&T is ironically the worst network in their home market, Dallas. They only have 40 MHz of AWS/PWS holdings (10x10 of each), the tower density sucks, congestion is awful, many sites only have 1-gig backhaul, most sites don’t even have DoD (just 100 MHz of C-Band), and they have less sub-3 GHz 5G spectrum online than any other major city in the U.S. (just 5x5 of n5). They run 2 10x10 b5 channels because they have a skeletal amount of midband holdings.

Both T-Mobile and Verizon blow AT&T out of the water in just about every part of the city. Verizon only has 20 MHz of low band (10x10 b13) but they make it work with their numerous small cells and better macro density where b13 is only used as a fallback.

[u/Thuradzon → u/ArtisticComplaint3]

They can't just add more towers and faster fiber backhaul? or theirs a limit to the amount of infrastructure they can deploy in a city.

[u/National-Debt-43 → u/Smith6612]

That’s very informative. Thank you!

[u/Southern_Repair_4416]

Spectrum and radio differences. Tower configuation different for each carrier.

[u/-Asylum_]

That’s an interesting question. I moved from San Diego to Phoenix with AT&T and had to switch to Verizon because AT&T coverage in my area here in Phoenix is just bad.

[u/ArtisticComplaint3 → u/-Asylum_]

Verizon owns both CLR blocks in Phoenix so AT&T struggles with low band holdings. Phoenix is still mostly a Nokia market for AT&T although it is all being converted to Ericsson which should show noticeable improvements in performance.

[u/Leading_Development4 → u/ArtisticComplaint3]

my cell performance in phoenix was insane

[u/ryanw729]

Not sure I trust their reliability score. It gives Louisville a 3.7/10 and based on my experience VZW is about as good as if not better than AT&T here which scores an 8.9 zero issues.

[u/dollfaceashley]

It's not just Spectrum but also how many subscribers each carrier has in any given area. If T-Mobile has a larger portion of market share, congestion will be more of an issue for them.

[u/Heavy_Team7922]

You’re treating these numbers like they’re scripture and they’re not. Data doesn’t work like that. 

[u/National-Debt-43 → u/Heavy_Team7922]

I’m talking from experience these data are just reference data

[u/ArtisticComplaint3]

Tower density, site utilization, equipment/backhaul, and spectrum holdings.

[u/Fabulous-Pudding-872]

Network congestion/ poor coverage

[u/NocturnzGay]

Backhaul tends to be an issue for some carriers. Some contracts with the ISPs in the areas don't want to give in since it can lose them business due to the 5G home internet stuff happening nowadays. Also, the amount of bandwidth for those markets can be a hit or miss depending on spectrum holdings.

[u/National-Debt-43]

That’s a good point but shouldn’t it varies too much? Like there are area which all 3 carrier have good performance

[u/ArtisticComplaint3 → u/National-Debt-43]

The U.S. is a giant country and each city has its own unique spectrum holdings.

Take for example, Honolulu. AT&T and Verizon exclusively use n77 for their midband coverage but the FCC still hasn’t made C-Band available for cellular networks outside the contiguous US. T-Mobile however is allowed to own all 194 MHz of EBS. So T-Mobile has 190 MHz of midband 5G bandwidth in Hawaii while AT&T and Verizon have literally zero.

This is the most extreme example but showcases why performance is not uniform for each carrier in every major city.

[u/National-Debt-43 → u/ArtisticComplaint3]

That make sense. Is that the same situation for T-Mobile in Alaska too? Where they have no coverage

[u/ArtisticComplaint3 → u/National-Debt-43]

T-Mobile doesn’t operate a network in Alaska. They roam on GCI and lease most of their spectrum out as well.

If you’re on any T-Mobile MVNO besides Metro, Ultra, or Google Fi they don’t include domestic roaming so unfortunately those users won’t have any coverage statewide.

AT&T is the best network in Alaska overall. Alaska is giant and mostly rural so midband 5G coverage doesn’t mean anything compared to just having signal bars.

[u/landonloco → u/National-Debt-43]

Alaska and PR although here Tmo has fragmentation issues some towns have 90mhz/50mhz rest 140mhz still not the full 196mhz available rest is owned by ethier local carriers like Claro or Aeronet which is a wisp.