WiWavelength

No. Network Vision will impact every Sprint cell site and every square inch of Sprint coverage footprint. AJ

Likely, no one at Sprint. It is practically impossible to provide quality tech support for 50 million subs. So, come here to S4GRU where people care about the network and are knowledgeable. However, you may have to recognize that some problems are not feasibly solvable right now. You will likely have to live with that level of performance until Network Vision completely overhauls the network in your neighborhood. AJ

One, you are wasting your breath with tech support. Do you think that you are actually talking to engineers? Two, for a moderately loaded EV-DO network, 0.5 Mbps average downlink rate is about par for the course, as absolute peak downlink rate is 3.1 Mbps. Do you truly need greater than 0.5 Mbps? That is perfectly usable throughput for nearly all sensible activities on a mobile phone. AJ

People, Robert's main points are completely valid. Sprint gets criticized for releasing LTE devices without a live LTE network. So, to placate some of that unrest, Sprint unleashes access to partly completed markets. And now Sprint gets lambasted for that. Some people will never be satisfied. "I want it 100 percent, and I want it yesterday" is just not possible in this situation. AJ

Hey, I was across the street from a crowded stadium, carrying my spectrum analyzer in a metallic briefcase, wearing my leather gloves and black ski mask just like a normal person. It was not as if I looked like a terrorist. AJ

Hmm, are those police sirens I hear? They sound like they are getting closer. AJ

Yes, one likely possibility that tends to go overlooked in this debate is that Sprint's average LTE data speeds may actually trend FASTER over the next few months. To explain, Sprint has launched current LTE markets with typically less than 50 percent of all sites live. So, as time goes on, the number of live LTE sites in those markets will double or even triple until completion. And that will not just double or triple capacity, it will increase it geometrically because 1) users overall will be spread across a greater number of LTE sites (i.e. fewer users per site) and 2) users overall will be more likely to be closer to LTE sites (i.e. stronger signal, higher data rates). AJ

Assuming the speed test is the real deal, that is about as good as it gets, a maxed out connection in all facets: all Resource Blocks allocated to one user, 64-QAM, and two spatial channel MIMO. AJ

You mean this guy? AJ

And Rawvega, while I quoted your post, I did not do so with any intent to single you out. My immediate reaction upon reading Neal's article was to call him out for his well known T-Mobile allegiance, to dub his article nothing more than a T-Mobile slanted downpour on Sprint's shiny new LTE parade. But I know that I can do better, that we all can do better. Cheers... AJ

On a related note, I have observed several times what appears to be uplink transfer rate shaping. Note the early burst, then significant drop in the uplink transfer rate vs time graphs. Honestly, if true, uplink rate shaping would make sense. Most uploads are relatively small -- no more than 1-2 MB. So, provide high uplink throughput for the first 1-2 seconds. That will complete most uploads, give the appearance of faster speeds, and get the uploader off the network more quickly. Any other observations of this phenomenon? AJ

Well, technically, the uplink, too, can use MIMO. WiMAX can utilize uplink MIMO. But, as I mentioned the other day, it was just too soon, the technology too immature. However, uplink MIMO will return with LTE Advanced. AJ

My response to the article: My response to cameron b's comment: My response to Neal's comment about backhaul capacity: My response to Neal's comment about Sprint's spectrum resources: AJ

I have been quite impressed with the quality of the comments following the inherently flawed ExtremeTech article. I firmly believe that the showing today demonstrates that S4GRU is both serving an important educational purpose and attracting an already learned membership. If you posted any response to the article, I encourage you to copy and paste it in this thread, so that current and future S4GRU members can benefit from your well thought out rebuttals. That said, please keep character assassination out of the issue. No matter how vehemently you disagree, ad hominem attacks never logically strengthen your counterarguments. I know Neal Gompa reasonably well -- as well as one can truly know an online colleague. He is a genuinely intelligent, definitely knowledgeable observer on the wireless industry, and I value his input. While he made several mistakes in publishing the current article, address his errors, not his person. That he is a strong T-Mobile supporter is no character flaw in and of itself -- unless many of us are willing to indict ourselves for being what most others would deem staunch Sprint supporters. So, I ask that we do not let the debate devolve into a holy war, a bunch of Sprint users ganging up on a T-Mobile zealot. We have all seen those types of exchanges, and they almost never serve any productive purpose. Rather, maintain the focus on facts and logic on both sides. Then, all participants have greater opportunity to come away from the discussion better informed. Thanks... AJ

Yes, it is a Spectran HF-6065 V4. It has its quirks, but it serves my relatively simple purposes of observing deployed/fallow spectrum, identifying airlink types, and measuring occupied bandwidth quite well. The USB connection and freely downloadable spectrum analyzer software round out a nice overall package. Let me know if you have any questions about it... AJ

If you think that the article is informative enough to share elsewhere, we would be honored. Thanks... AJ

...but give them read only access. Otherwise, spare us the ill informed but highly vocal complainers. AJ

Nah, I would give you at least 11¢ for that well formulated comment. Very nice job. AJ

Neal is a strong T-Mobile advocate. Maybe this is just speculation on my part, but Neal is probably influenced by a bit of envy, as Sprint's significant jump start on LTE is coming to fruition. And T-Mobile is once again the odd man out in the mobile data scene. We all let sentiment and irrationality get to us sometimes. But that does not excuse disseminating specious info that is so contrary to fact. AJ

Absolutely. Different sectors on the same site or even different sites altogether. And this has long been true of CDMA1X and EV-DO, too. AJ

Neal Gompa is a friend of mine and usually knows his stuff, but this is without a doubt a speculative, "poorly researched" article. Kudos to S4GRU member irev210 for a strong, factual rebuttal. http://www.extremete...h-to-domination AJ

A handset is programmed to idle on/connect to the site with the most favorable signal level, and that may not be the closest site. Additionally, the handset is programmed to seek the highest protocol revision (e.g. LTE > EV-DO) that it supports. For example, the closest site may not yet have LTE deployed, but the LTE signal from a more distant site is usable. Finally, keep in mind that CDMA1X, EV-DO, and LTE signals are all tracked independently, so a handset can idle on/connect to different sites for the different airlinks all simultaneously. AJ

For an interesting bit of supplemental info that I decided not to include in the article, VZW has thrown its support behind RSSI and has made effort to standardize its devices around that measurement. For example, see this document: http://support.veriz...e.html?id=37249 The upside is that LTE RSSI is always greater than RSRP. For VZW 10 MHz bandwidth LTE, RSSI should be approximately 23 dB greater than RSRP. And those larger numbers may be artificially reassuring to end users. But there is a price to pay -- the signal strength simply gets skewed toward larger numbers. Note how the VZW document states that "RSSI should be greater than -58 dBm" and that "-96 dBm indicates no signal." The former seems surprisingly high as standard signal level, the latter likewise for no signal level. However, subtract 23 dB from each measurement to convert roughly to RSRP and get -81 dBm and -119 dBm, respectively, both of which are largely in line with observed performance from Sprint LTE so far. AJ

by Andrew J. Shepherd Sprint 4G Rollout Updates Monday, July 16, 2012 - 1:40 AM MDT As Sprint LTE 1900 has become live and discoverable in numerous markets over this past weekend, some of our readers, especially those who are using Android 4.0 ICS based ROMs, have expressed concern at the seemingly low signal levels that they have encountered. For example, see this screenshot from an HTC EVO 4G LTE (under Settings > About > Network): Note the -102 dBm signal level. If this were measuring CDMA1X or EV-DO, then, yes, -102 dBm would be nearing the margin of usable signal. But -102 dBm is actually relatively healthy LTE signal level. To understand why, we need to learn the differences between two types of signal measurement: Received Signal Strength Indicator (RSSI) and Reference Signal Received Power (RSRP). First, an LTE downlink is divided into subcarriers. A 5 MHz bandwidth downlink, which is the configuration that Sprint is deploying, contains 300 subcarriers. And of those subcarriers, one in three carry LTE reference signals. In other words, of the 300 subcarriers, 100 transmit periodic reference signals. To illustrate, I captured this power vs frequency sweep with a spectrum analyzer. The LTE downlink graph comes from a Sprint site in the Kansas City area in late April, well before Sprint stopped blocking devices from live LTE sites. So, the sector depicted here exhibits no data traffic; it is transmitting only the periodic reference signals on 100 subcarriers, which you can clearly count in the graph: Now, RSSI is the more traditional metric that has long been used to display signal strength for GSM, CDMA1X, etc., and it integrates all of the RF power within the channel passband. In other words, for LTE, RSSI measurement bandwidth is all active subcarriers. If we take the above RF sweep of a Sprint 5 MHz bandwidth downlink, RSSI measures the RF power effectively of what is highlighted in yellow: RSRP, on the other hand, is an LTE specific metric that averages the RF power in all of the reference signals in the passband. Remember those aforementioned and depicted 100 subcarriers that contain reference signals? To calculate RSRP, the power in each one of those subcarriers is averaged. As such, RSRP measurement bandwidth is the equivalent of only a single subcarrier. And using our graph once more, RSRP measures the RF power effectively of what is highlighted in red: Since the logarithmic ratio of 100 subcarriers to one subcarrier is 20 dB (e.g. 10 × log 100 = 20), RSSI tends to measure about 20 dB higher than does RSRP. Or, to put it another way, RSRP measures about 20 dB lower than what we are accustomed to observing for a given signal level. Thus, that superficially weak -102 dBm RSRP signal level that we saw previously would actually be roughly -82 dBm if it were converted to RSSI. To conclude, here are a few takeaways about RSSI and RSRP as signal strength measurement techniques for LTE: RSSI varies with LTE downlink bandwidth. For example, even if all other factors were equal, VZW 10 MHz LTE bandwidth RSSI would measure 3 dB greater than would Sprint 5 MHz LTE bandwidth RSSI. But that does not actually translate to stronger signal to the end user. RSSI varies with LTE subcarrier activity -- the greater the data transfer activity, the higher the RSSI. But, again, that does not actually translate to stronger signal to the end user. RSRP does a better job of measuring signal power from a specific sector while potentially excluding noise and interference from other sectors. RSRP levels for usable signal typically range from about -75 dBm close in to an LTE cell site to -120 dBm at the edge of LTE coverage. Sources: 3GPP, author's graphs

Not to be a stickler, but what you say about WiMAX is not necessarily true. Basically, WiMAX comes in two varieties -- fixed and mobile. Clearwire has deployed 802.16e, which is the later, mobile variety. It can manage handoffs perfectly well. Because of Doppler shift and other factors, mobility does affect all OFDM based airlinks, including LTE. But, for WiMAX, the problem is largely that Clearwire did not deploy enough cell sites for BRS/EBS 2600 MHz propagation, leaving coverage gaps between sites. AJ