WiWavelength

After the VZ-Cable/VZW-SpectrumCo transaction, I have taken a *vow* to avoid VZW. AJ

I have MCC-MNC 310-120 for Sprint LTE. Do you have anything different, any variation? AJ

Canadian CDMA2000 providers in Ontario are Bell and Telus. At your indicated location, it looks like you might have CDMA1X coverage, most likely from Bell, which is the wireline incumbent in much of the eastern half of Canada. You can view coverage maps online: http://www.bell.ca/Mobility/Coverage_map http://www.telusmobility.com/en/ON/canada_travel/3G_canada_travel.shtml AJ

I just hope that my fantasy football team this year does not experience as much "backhaul failure" as it did last year. AJ

Can you talk further about the field test parameters included in these Clear devices, maybe post some pics? I might be interested in picking one up just for WiMAX testing purposes, since I have effectively retired my WiMAX handset. AJ

Yes. Many devices released over the last several years support band class 10 CDMA1X 800. And the only devices Sprint has released recently that do not are the iPhone 4/4S. AJ

That high, you are gaining line of sight to an LTE equipped site much farther away. Nobody tell the FCC or FAA, but on flights at 30,000 ft, I have connected to sites a hundred miles distant in the adjacent MTA -- my experiments were for educational purposes only, of course. AJ

I consider myself to have only rudimentary understanding of the matter, but I believe that MIMO is more effective with LTE (OFDMA) and less effective with W-CDMA because of two factors: LTE symbol rate is much slower than that of W-CDMA, thus more resilient against multipath. LTE FDMA allows MIMO to be applied across only selected Resource Blocks, as appropriate. AJ

The impact on non MIMO devices may be "minimal," but it is present, as those non MIMO devices cannot take advantage of the MIMO pilot. Hence, they experience it as added interference. AJ

Nope, just the opposite. T-Mobile's HSPA+ 42 is entirely Release 8 Category 24 (i.e. DC-HSPA+). T-Mobile has not deployed MIMO, which is not as effective with W-CDMA and somewhat detrimental to non MIMO mobiles. As an addendum, this is why some T-Mobile markets are only HSPA+ 21. In those markets, T-Mobile has only a single AWS 10 MHz license or two non contiguous AWS 10 MHz licenses. AJ

To be sure, have you verified the same PN offsets for CDMA1X 800 and CDMA1X 1900? Also, if indeed the same site, could CDMA1X 1900 still be from legacy infrastructure, while CDMA1X 800 is from Network Vision infrastructure? AJ

But, to this point, DC-HSPA+ is all contiguous carrier aggregation. To my knowledge, no one -- certainly not T-Mobile USA -- has deployed any non contiguous DC-HSPA+. AJ

I will be happy to be proven incorrect, but my understanding is that Release 10 non contiguous carrier aggregation (whether intra- or inter-band) requires a separate FFT for each carrier to be aggregated. And that will require handsets to have substantially greater radio resources at their disposal. Thus, I remain unconvinced that non contiguous carrier aggregation is going to be commonplace anytime in the next several years. AJ

The iPhone 4/4S has external antennas (the silver bands around the edges of the device). While these antennas have been problematic, as they can easily be shorted by contact with human skin, they likely do provide a link budget (i.e. transmission/reception) advantage. And knowing how overly litigious Apple can be, it probably would sue the pants off of any other OEM that built a smartphone with external antennas. AJ

After that many handsets, the common denominator is you. Are you, perhaps, a source of static electricity? You do come across as something of a spark plug. AJ

I fully suspect that you are right and that the location across from the Sprint Campus is little more than coincidence. I need to get out and do more BRS/EBS 2600 MHz sweeps before Clearwire starts paring down any WiMAX bandwidth to make way for TD-LTE. Just create a new $1000 Gigante Supremo Sponsor level, and we could probably make that happen. AJ

I do not think that anyone is arguing that 10 MHz FDD has no advantages in theory. However, I would like for you to elaborate on your cell edge contention. The scenario that I think you are suggesting is that 10 MHz FDD has twice as many Resource Blocks available, hence a cell edge user that has radio conditions that can support only a very low modulation and coding scheme (e.g. QPSK and 1/2 FEC) can be assigned effectively twice as many RBs to maintain higher throughput. But the above scenario assumes that all other factors are equal. In actual practice -- as deployed by VZW -- 10 MHz FDD is not necessarily equal in all other factors. Compared to Sprint, VZW has twice as many subs (a reasonable approximation) and LTE cells twice the size (a ballpark estimate). Some back of the napkin math has VZW trying to support four times as many subs per cell on only twice the bandwidth. Yeah, 10 MHz will still hit twice the peak speeds of 5 MHz FDD, but its average speeds should be no better, nor should its average cell edge speeds, as proportionally many more users are competing for those RBs. I think the biggest reason for pushback, though, is simply that Sprint cannot realistically deploy 10 MHz FDD in more than a handful of markets right now and not in a majority of markets until the EV-DO shutdown in 3-5 years. So, with Sprint, 10 MHz FDD is just not in the cards for a while. Plus, VZW's parent company is becoming an awful, awful corporation -- almost on par with AT&T -- that wants to shirk its responsibility to compete in the wired broadband market. So, VZW should get no love from anyone who respects what is good for the domestic wireless industry and connected America as a whole. AJ

Watch out for your cornhole...and your threshole, too. AJ

Most likely, yes. Thanks, I have corrected it. But it may have been something of a Freudian slip. For some additional background, the anomalous 5 MHz carrier comes from a site literally across the street from the Sprint Campus in Overland Park. Robert and I were initially intrigued that this might be a 5 MHz LTE TDD or FDD test carrier in BRS/EBS 2600 MHz spectrum. But I could not locate any further evidence to substantiate that hypothesis. AJ

Good stuff. We definitely appreciate your report. Like LTE, WiMAX is a variable bandwidth, OFDM based airlink, so RSSI is not an ideal measure -- it will always be a bit inflated. "CNR" is referring to carrier to noise ratio, measured in dB. And, yes, it is basically interchangeable with signal to noise ratio. Transmit power is frequently measured in dBm (dB above 1 milliwatt). So, true, -14 dBm is ~40 microwatts. The "Bandwidth" metric is referring to WiMAX carrier bandwidth. Most carriers are 10 MHz TDD. But I have found a somewhat rare 5 MHz TDD carrier on at least one site in Kansas City. I have talked at length with Robert about this seemingly unusual carrier, but I do not believe that I have posted about it. So, here are a few RF spectrum analyzer captures: The first sweep is of the entire BRS/EBS 2600 MHz band. At this location, you can see three WiMAX carriers: a 10 MHz carrier ~2530 MHz, the aforementioned 5 MHz carrier ~2575 MHz, and a faint 10 MHz carrier ~2630 MHz. The second sweep is a zoomed in look at the 5 MHz TDD carrier. AJ

Guys, RF frequency (e.g. 800 MHz, 850 MHz, 1900 MHz) is not the issue. The cause of the audible speaker interference is TDMA burst frequency. GSM is most notable in this regard, as its TDMA burst frequency is 216.67 Hz for full rate, 108.33 Hz for half rate -- both of which are well within the audible range of 20 Hz - 20 kHz. In other words, a traffic state GSM mobile transmits powerful RF bursts a few hundred times per second, and unshielded electronics may reproduce the frequency of these bursts as an audible buzz. AJ

What was I thinking?! To shock and awe Odell, I need to obscure image URLs by uploading them to TinyPic and not directly quote his posts. Consider it a lesson learned. I will do better in the future. AJ

You mean like these guys... Yeah, they appear to be carrying some EVO 4G LTEs in the front of their "banana hammocks." AJ

Very true. This is not an issue with the MSM8960 baseband. Rather, it may be an issue with the ancillary equipment (e.g. RF transceiver, power amps, antennas). Or it may just be an issue with the decisions of the OEMs, carriers, and FCC authorized testing labs. If the testing lab does not test and report on a particular LTE FDD configuration, then that configuration cannot be used on said device. AJ

Well, 2048 LTE subcarriers would have an occupied bandwidth of 30.72 MHz. So, that would not be the 20 MHz configuration. For example, LTE FDD 5 MHz configuration (Sprint and AT&T) occupies 4.5 MHz bandwidth and uses 300 subcarriers, while LTE FDD 10 MHz configuration (VZW and AT&T) occupies 9 MHz bandwidth and uses 600 subcarriers. LTE FDD 20 MHz configuration would occupy 18 MHz bandwidth and use 1200 subcarriers. While it may be that all LTE basebands must be fully capable of receiving 2048 subcarriers, no real world network that I know of even approaches that configuration. As an aside, writing this post made me think that a great T-shirt slogan for wireless nerds would be "Occupy Bandwidth." AJ