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MrZorbatron

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Everything posted by MrZorbatron

  1. Didn't say WCDMA isn't spread spectrum. I just said its signaling doesn't work with a negative SNR. LTE, by the way, with its multiple subcarrier approach over a wide frequency range, does qualify as a spread spectrum technology. It isn't a frequency-hopping spread spectrum, but it is a wideband spread spectrum signal. Inter cell interference coordination improves performance where cells overlap, not where cell sites are too far apart. Your post didn't tell me anything I didn't know, and trust me, I would have considered it or even wrote it if it mattered. Unfortunately, it doesn't matter at all in rural cell's edge coverage. This is all great and quite necessary in an urban cell situation, in which case one cell might be overlapped by 10 others or more, in varying degrees and in varying locations. This does no good at all in widely spaced environments. On rural PCS site spacing, VoLTE simply will not work well because those sites were spaced for a technology that was more robust in the case of fade and weak signal. Why don't you do this... Take a compass or circle template and draw a few circles, much as a cellular network would be laid out, trying to cover as much as possible of your paper with as little overlap as possible. Remember, your anti-interference techniques are great and all, but each and every one reduces capacity, so it's best to marginalize their use whenever possible. Use red ink. This is your CDMA2000 coverage. Now, dial your compass down about 5-6% and make new circles using green ink, using all the same center points. This is your effective LTE coverage. Even though the signals on both technologies extend beyond the circles we have drawn, the circles visualize the usable range in which there will still be sufficient signal for your phone's radio to operate properly. Look at all the holes! "Hole"y s**t, there are a lot of dead zones! Now, it should be noted that this only takes open air signal losses into account. In a wooded area, or with building obstacles, this problem becomes even more serious.. Plain and simple, LTE needs more signal to operate at all, and where that signal isn't there at that level, your phone won't work. Shifting power within a signal won't work to fix this. Incidentally, I agree with your last paragraph and will add something to it. Pushing LTE technologies so far in order to service edge of cell users will absolutely destroy performance closer to the center of the cell.
  2. Qualcomm, like all other radio manufacturers, can refine the radio. This might improve its sensitivity, as well as its stability in a low signal environment. It doesn't do anything at all to change that due to the fundamental design of the signal, LTE is inherently more susceptible to noise/fade and dropoff at the edge of the cell. Remember what I said about how CDMA2000 can operate (at a reduced capacity) in an environment with a negative signal to noise ratio? Negative SNR means that the radio is hearing more interference than signal. LTE can't do that, and neither can UMTS/WCDMA. This is why 1x/1xA is a better voice standard, period. No amount of refinement to LTE radios will change that. If you can improve the sensitivity of the LTE radio, you can similarly improve the sensitivity of the CDMA radio, and again the CDMA regains its lead. As for Qualcomm being the leader in WCDMA, they aren't. There are many manufacturers of WCDMA/3GPP chipsets. Qualcomm is the leader in 3GPP2 chipsets. No. LTE already does some of this. It IS a spread spectrum signal, it DOES prioritize subcarriers with lower interference, it does use an adaptive downlink at the base station end according to what the mobile reports back for its reception. RSRP wouldn't change there, as it is a composite of all subcarriers. Prioritizing subcarriers makes no sense because adaptation to interference is a much better idea. All subcarriers need to be transmitted and received with approximately the same amplitude for the signal to work properly, so it is unlikely that you could improve the strength of a very few subcarriers for voice. Also, if you limit LTE to just a few subcarriers for high reliability, its spectral efficiency drops substantially below CDMA2000/1x, which can make it through this level of interference without a hitch already. This makes no sense.
  3. VoLTE will NOT improve coverage and penetration. It will WORSEN it! The LTE signal is far more fragile and no amount of tinkering with the standard will both reverse that and maintain compatibility with other LTE devices!
  4. Perhaps Alltel wasn't for sale yet at the time Sprint bought out Nextel. I didn't mean specifically cash, I just meant the means to buy it. Either way, taking over a compatible carrier is substantially cheaper than an incompatible one, any way you look at it.
  5. This isn't what I meant. Sprint did have the cash to buy Metro but the board didn't accept it. I agree that Sprint is in a better position with Softbank, though the complications go far beyond. You look at things through simplifying glasses I am afraid.
  6. Incidentally, the problem with VOLTE remains no matter which frequencies it uses. LTE doesn't live with a negative SNR. CDMA does. This means that CDMA is an inherently better technology in cases of either marginal to weak signal strength or high interference areas.
  7. Absolutely a mess. It would be Nextel all over again. This is why Metro is the only piece of TMO that would have been worthwhile to Sprint, and it strains reason to try to figure why they did not buy Metro when they could.
  8. No. Sprint "installing new gear" in a TMO area post acquisition would be no more cost effective than simply leasing tower space and installing their own machinery in those areas now.
  9. Yes and no. Moving Metro to Sprint CDMA would be EXTREMELY easy, far easier than migrating them to UMTS, In fact, as more time passes and the more migration work of Metro users to the TMO network happens, potential of a merger between TMO and S becomes all the more distasteful.
  10. Yeah but once 2500 is built out in a market, it will not be cost effective to divest it. To me, this means that they ate stuck with it unless they can sell Clearwire in its entirety to somebody else for a fair price. To keep it iin some markets and not others would just introduce another bastard frequency/technology that is barely deployed but many devices will have to support, just like WiMAX all over again. Also, do not forget Softbank's compatible network in Japan.
  11. In some markets they do not have both, but one or the other.
  12. Sprint's TD-LTE offerings are all based in BRS and EBS, so they can't lose it right now.
  13. I am always surprised how many strange, totally nonsubstantiatable things regarding batteries that are floating around out there, often perpetuated by people who place themselves in a position to advise. For example, Verizon tells people it is best to charge a phone only when the battery is below ten percent charge and then to charge it all the way without interruption. The latter part is accurate, but the former couldn't be more wrong. It also happens to be the same recommendation given with by Verizon with my old analog Motorola DPC550, which used a NiMH battery, in which case, as with all nickel based chemistries, it is the correct recommendation for proper battery care. I love debate, but I steer clear of the battery subject now, since 9/10 things popularly perpetuated are wrong.
  14. I absolutely agree about car chargers with typical use. the problem isn't with car chargers, but with the way people use them. There are 4 basic behaviors that are injurious to lithium batteries: One is never disconnecting in the charger, the endless float. Phones don't usually have the smartest charging circuits. A good charging circuit will go to standby and not engage until the charge level is below 95% or so, even and if disconnected and reconnected will still not begin charging if the battery is over 95%. Remember that it is possible to run the phone off of external power without the charging circuit being connected to the battery. The second is repeated shallow charging. This is where somebody runs a battery down by just a few percent, and then charges it by another few percent. This is what happens with car chargers, plug in at 45%, unplug at 49%, plug in at 23%, unplug at 28%, so overall the charger meter doesn't move by more than 5 or 6 percent. The third is prolonged and deep discharge. Never store your battery flat dead. Charge it to 40 to 60 percent, and put it away somewhere out of direct sunlight or heat, ideally with temperature that will never get above about 75 degrees fahrenheit. The fourth is repeatedly topping it off, which more or less fits into #1. If your battery is not run down by more than 10 percent, say to 85 or 90 percent, don't charge. Thinkpad models, for example, won't engage the charger circuit if the battery charge is above 94 percent, unless the charging behaviors are altered. The computer will run on the adapter, but not connect The charging circuit to the battery. Another big thing to remember is that your battery may be good for a half life of 500 cycles, which means your capacity falls by half in 500 cycles of charged to dead and back, but if you only half-cycle it, with a maximum charge mobility of 50%, you will get around 1400 half-cycles, so the half life effectively becomes 700 cycles. Remember that the loss of capacity is not an immediate thing that happens once you hit that magical half-life cycle count. Capacity is lost each and every cycle. Once you hit that half way point, now you have another 500 or whatever cycles until your capacity halves again, for 25% of your original design capacity, and so on. That's why we see laptops with VERY weak batteries that work for ten minutes or something, despite claiming 100% state of charge. The bottom line is that you should always charge for at least 15%, avoid running below 10% frequently, don't top off for the hell of it, and remember that for every 24 hours your phone is flat dead, your full charge capacity falls by about .8%. Cheap chargers aren't a big deal anymore because the charging circuit on anything with USB is built into the phone, so you don't have to worry there, as long as you are getting a relatively clean 4.8 to 5.2 volt power supply. Original post was written mostly by Google dictation. It is now edited to clear up formatting and some remaining word mistakes, for easier reading.
  15. The charging circuit in the phone does not allow the battery to be overcharged. The recommendation to unplug the charger isn't for the phone's sake, but for the use of electricity by the idle charger remaining plugged into the wall. While it is true that batteries using lithium based chemistries do not like being stored at full charge, this does not mean that float charging them for a few hours will damage them. If it were days on end that the device remained plugged in, I could see some chemistry related issues decreasing battery life, but not over night. Incidentally, this phenomenon is related to migration through cell dividers, not overcharging. Overcharging of a lithium based battery is bad, very bad, at least damaging the battery instantly, at worst, this damage is catastrophic and possibly pyrotechnic in nature. As for the wakelock bit, absolutely. There are great programs out there that will specifically display wakelock activity, GSAM battery monitor is one of them. And before someone starts arguing by presenting articles written by silly popular tech sites on the internet, let me tell you that those articles aren't written by electrical engineers. This post was.
  16. For a SGS3, this is very very bad battery life. Sounds like you have a background application that uses a lot of data when it sees a fast connection. I personally notice no difference in life between CDMA only and LTE areas. I can run the hell out of my S3 and it wouldn't die in less than 5 or 6 hours of continuous screen-on use.
  17. Yeah the 169 thing doesn't apply here. The LTE sectors aren't sequentially numbered, but I can't find any pattern at all to them. We have a site nearby that has sectors 465, 20, and 414. The only thing I know must be maintained is that there cannot be two identically numbered sectors within radio range of each other.
  18. Just a cool candid of my girlfriend, taken last November. Any of you in SE Michigan should seriously check out this place, The Oakland Art Novelty Company.
  19. There is a site with those ugly tube covers near me. I have no idea what they are thinking with this. It must make service a much bigger pain.
  20. Yeah, I think it's all cyclical though. I was just looking at specs for a new device that runs 1Gbps over 50 ohm coax, fed by a GigE circuit, to extend the run distance at a lower cost than fiber. Didn't we just move from coax to twisted pair about 20 years ago... Or what about how everyone with multiple closely located sites was running 10-40Mbps microwave a big ago and then fiber got cheap enough that they started running their own fiber on leased space on utility poles about 10 years ago. School districts and municipal services are a great example of this. Now microwave is getting cheaper again, albeit still ugly if you can't hide the hardware. I really do think that a lot of this is on about a ten to twenty year cycle, at least on the physical side of things.
  21. it has been for years. Multi-gigabit optical isn't a new technology. Microwave wise, I can practically run 2 gigabit a few miles (with line of site) for under $10000 with my eyes closed. That's not a new technology either. The low price is new, though.
  22. Fine tuning takes weeks, but isn't like a constant effort. Some of it is automated. Radio power levels and antenna element angles can be adjusted electronically, without service calls. Traffic management and allocation of backhaul bandwidth is now dynamic. This modern network equipment is even aware of its surroundings, allowing automatic mitigation of interference through neighbor-negotiated frequency hopping patterns, power output levels, and antenna angles.
  23. Old news. It won't work. In order to fit enough antennas into the device, they had to use too high a frequency to be practical. Attenuation in building materials and even in foliage would make it useless without line of sight. It's not "5G", it's just a new transmission method. Referring to it as 5G was just a way to get people to read the article. LTE has a LOT of headroom left in it for expansion within the spec (hence its name), so don't expect it to be replaced for many years.
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