11-22-2011 08:00:52 AM
I've noticed that my Samsung Focus S lies about 4G. It *never* shows 3G coverage, only 4G. I assume this is HSPDA+, but the problem is, that isn't available in my area! Every AT&T coverage map shows that it is over 30 miles away from HSPDA+, but my Focus S keeps saying 4G.
To me, the evidence that it is just a 3G icon relabeled as 4G is that my A&T Microcell even shows up as a 4G connection now. I'm pretty sure it doesn't run HSPDA+
I honestly don't mind AT&T calling HSPDA+ 4G. I *DO* mind them calling their 3G coverage 4G, and not indicating what my true connection is. That is flat lying.
11-22-2011 02:45:23 PM
I do agree that the status bar should truly reflect the current connection and not just the highest level of connection it is capable of.
11-22-2011 06:20:02 PM
The about screen doesn't show a signal type from what I can see.
It also correctly identifies GPRS & EDGE with their own icons. The only issue is that everywhere that should say "3G" says "4G", regardless if it is 4G or not.
11-23-2011 02:30:44 AM
04-03-2012 12:36:18 AM
In UMTS, there are multiple air interface standards - W-CDMA, TD-CDMA, and TD-SCDMA. Unless otherwise specified, any reference to UMTS is referring to the W-CDMA flavor. This uses a CDMA air interface on two paired channels - an uplink and a downlink channel. 5MHz each. The pair is widely referred to as a carrier, and usually referenced by it's downlink channel number (in my market, AT&T runs two UMTS carriers - 1007, and 562. These are not the frequencies they're the DL channel numbers aka UARFCN - UMTS Absolute Radio Frequency Channel Number).
Too overwhelmed yet? I hope not. The original "Release 99" UMTS W-CDMA only supported up to 384kbps downstream in a single channel. Additional releases and categories increase this data rate. Increases in the downstream are referred to as HSDPA (High Speed Downlink Packet Access, not HSPDA), increases in the upstream are referred to as HSUPA (High Speed Uplink Packet Access). Increases in both are just HSPA. Beyond a certain speed, this is called HSPA+. On the downlink, category 10 ("14.4mbps" - actually just under 14) and category 14 (21.1mbps) are often defined as these points. Though this is somewhat arbitrary, and regardless of network capability, your actual encoding may drop due to network conditions.
So, at what point should the phone say "4G" vs "3G"? Often, original UMTS only seems to be called 3G (this is a rare site in todays world), and any HSPA mode seems to be called "4G" on HSPA+ phones. This actually makes the most sense, since network conditions will often cause a drop in code rate well below a cell's capability. It'd be silly for a phone to switch from saying "4G" to "3G" when connected to the SAME cell but the raw bitrate dropped below, say, 14.0, due to poor SNR). In a very technical sense, the modulation is often the argument used. If it's 64QAM downlink or 16QAM uplink (higher order modulation is more efficient) it's often called "real HSPA+" by the tech elite online. The iPhone 4S is 16QAM DL. Thus people saying it's not "real" HSPA+. But what if it had 64QAM DL and QPSK (Quad PSK - so 4) uplink? Would it be "real" then? Many HSPA+ devices are there.
And what about, like I said, actual in-use modulation. I'm not sure if things have improved, but on a device that logged this, one person reported 64QAM was used by their phone on AT&T's network for less than 10% of packets in their drive test (granted, higher order modulation is more likely to fail in motion, results would likely be better sitting still IN A HIGH SIGNAL AREA). Should the indicator flicker between 3G and 4G depending on the modulation of the last packet?
AT&T's maps also only show "4G" if an area has HSPA+ *and* IP/MPLS backhaul ("enhanced backhaul"). The phone has zero way of knowing backhaul type. Most AT&T 3G areas are HSPA+. The phone cannot tell the difference.
So, with all this in mind, there are very good, valid, technical reasons for your phone to just display "4G" - at least as long as it's running in any HSPA mode (and Rel. 99 UMTS is downright almost unheard of these days - anywhere in the world).
04-03-2012 04:22:39 AM
Ah, a technical explanation! Thanks!
However, if we're being technical, there is no way HSDPA should ever be called 4G. If they want to make a brand difference between EV-DO since HSDPA is generally faster, then they should put a "H+" logo up there instead of the 4G.
There is no 4G service in the USA accoring to the ITU's first specs. It is only recently that they've caved and permitted 1st-gen LTE & Wi-MAX to be called 4G, but nothing has changed in terms of branding the 3G technology HSDPA as 4G.
This is just AT&T trying to lie & claim a large 4G network instead of building one.
04-04-2012 08:36:07 AM
The most PEOPLE used the term 4G to refer to a class of service the ITU called IMT-Advanced. The ITU was asked their opinion and issued a clarification that 4G is undefined and that they *recognized* it was being used to refer to "LTE and WiMax, and to other evolved 3G technologies providing a substantial level of improvement in performance and capabilities with respect to the initial third generation systems now deployed."
Note, ITU did not redefine this. Unlike 3G (defined by 3GPP), no major standards body has ever defined the term 4G.
I'm not saying AT&T's not overusing the term. I think they are when you can get under 2mbps in "4G" coverage. But it's a lot more technically complex. HSPA+ with MIMO (note... AT&T has not deployed MIMO on UMTS and who knows if they ever will, at least on a large scale, given the push to LTE) is very similar in efficiency to LTE. The only substantial differences are in latency and potential for future evolution. Raw data rates are very, very similar.
Dual bonded (5MHz) channels of HSPA+ with MIMO, 64QAM modulation, supports 84mbps downstream. First-gen LTE in a 10MHz channel supports about 100mbps. However, the overhead calculations are different (I believe it's 72 on LTE accounting for overhead, a bit less on the HSPA+). In other words, so close that small differences in network load matter more than the technology.
AT&T's not using MIMO or channel bonding yet. But saying LTE is inherently more 4G than UMTS, isn't really true. Both systems are capable of very fast speeds.
My proposal? Both AT&T and Verizon should do a few things to clear this up:
1. Change phone indicators to "H" (or H+ depending on phones capabilities), "LTE", and "EV" (for EVDO).
2. Market based on average speeds. These companies collect an insane amount of data. Map it. Let Verizon and AT&T show, on a map, average speeds for each technology they use actually being seen on the network. Color code it by cell site and map it. CTIA should create a mapping standard so these maps are directly comparable between carriers.
3. Open transparency about tech being used. No one talks about backhaul availability, site density, actual tech revisions in use. AT&T throws around the term "enhanced backhaul" - what on earth does this mean? The consensus online (presumably but not certainly leaked from inside AT&T) is that it refers to areas upgraded from circuit-switched to IP/MPLS backhaul. This definitely seems to line up with the latest coverage map update. Look at Montana... see all the nice new dark blue "4G?" Almost all of that area is extremely remote. It's not Montana's CITIES, it's Montana's remote rural areas. The places where cell sites are probably fed by microwave backhaul - which is easy to upgrade to an IP-based structure.
AT&T's doing a lot better than they were. I'll give them credit. They bought Alltel (divested from Verizon) in my state. They've continually been making massive network upgrades, and I get coverage and speeds I never imagined in my rural area. So many people left for Verizon even before AT&T took over based on AT&T's bad reputation here (since it was all bad roaming before), and once they took over, the network was seriously overloaded (since it was all running in a single UMTS850 channel) and didn't work well at all. However, they quickly began massive upgrades - UMTS1900 channels, tons of new cell sites covering large rural areas never before covered, etc. One guy I know switched to Verizon because his new AT&T phone had no signal at all at his house (UMTS is a wider channel than CDMA so it doesn't work quite as well in the mountains, and Alltel was very very weak). His Verizon phone always roams on the old Alltel network (which will get shut down in 2013 so hopefully Verizon adds coverage before then). Imagine his surprise when three months later, there's a new AT&T tower literally under a mile from him (in large cities that's a long distance but in rural areas the sites are setup to cover a much larger area).
Another friend who drives between Kalispell and Helena a lot switched because he lost roaming on Verizon. Alltel covered part of that road, Verizon covered a different part (with one town overlapping), and nobody covered most of it. AT&T has now almost completely overlapped Verizon's coverage (except at a small area where there is AT&T service from roaming on CellularOne), and, not only that, expanded their coverage to cover a much larger portion of that road than has ever seen cell coverage before.
All of this being HSPA+, and seeing speeds from 2-6mbps. In rural Montana. I'm a pretty happy camper and I hope AT&T keeps up the good work. Montana's always been a state with terrible cell service (of the big 4 carriers, only Verizon covered here). Sprint will never cover Montana (they sold their spectrum to AT&T recently, which is being used for the UMTS1900 carriers). T-Mobile owned spectrum here, which was leased to Alltel (they provided GSM roaming service in the big towns). Prior to the attempted AT&T/T-Mobile merger, T-Mobile was planning to launch UMTS here by year-end 2013. I don't know if that plan has changed or not. In the last few months they've started lighting up quite a bit of UMTS-only rural America (look at T-Mobile's data map for Arizona and compare it to their voice map which only shows GSM right now). It might happen.
Granted, my example is just my state, but I've heard similar reports from all over the country. AT&T has said game on. They might seem a bit late to the LTE party, but they're not really. Verizon's just really early (because EVDO is so slow they had little choice). Good UMTS is more than adequate for today's smartphone applications if there's enough capacity - and battery life is far superior.