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  1. #21
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    What are you saying the transmitters have unlimited power on a cell tower? They specifically said 2.0 and 2.0.1 has a power management bug that requests way too much transmit power from the tower, on a busy tower that happens to have other 3g iPhone users with 2.0 and 2.0.1 this can cause slowdowns for everyone using 3g regardless of phone and if there are enough the tower will start dropping calls when it hits it's transmit power threshold, which is limited in total watts by the FCC. GSM/edge is not affected since it is whole separate radio system running in parallel with the UTMS/3g on the same tower.

    This makes sense from my understanding of UTMS and radio technology in general, and honestly their explaintion seemed much more concrete than your non technical response. If you want to give details of how this is BS please do so.

    I'm taking it with a grain of salt, but it would explain quite a bit and certainly doesn't violate the laws of physics or anything.

  2. #22
    Moderator iProb8's Avatar
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    Quote Originally Posted by Justin View Post
    Ok those holding off on the 2.0.2 update need to go for it, looks like 2.0 and 2.0.1 phones can affect other running 2.0.2, that's why at&t sent out the text to upgrade, because 2.0.2 only helps if the majority of phones on a a tower are using it: The Inside Deets on iPhone 2.0.2 and Dropped Calls — RoughlyDrafted Magazine
    IMHO, the issue in the article does not help explain why, when I had 3G turned on, I was consistently dropping calls, in the same two places in the neighborhood by my house, as well as a spot near by office. For the two spots in my neighborhood, each was no longer than 100 yards (probably less than that) and both spots were within 1/4 mile of each other. I find it hard to believe that at those three spots, the dropped calls were due to power management problems.
    -Jay
    The Fine Print:Nothing in this post (or any of my other posts) is intended to constitute legal advice or the establishment of an attorney-client relationship. For purposes of this forum, I'm just another nerd like you. :-)

  3. #23
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    To backup the power control issue here are some technical docs that explain UMTS power control in more depth:

    Power Control in UMTS « Mobile & Wireless
    UMTS Power Control

    From the first one:

    "From the point of any cellular network, proper power control helps in keeping interference at a manageable level while improving capacity and the overall service to the mobile subscriber."

    And

    "UMTS, unlike GSM, has a greater need to combat the near-far problem. A UE close to the Node-B transmitting at the same power as another at the cell edge, will potentially block out the latter."
    Last edited by Justin; 08-28-2008 at 11:20 AM.

  4. #24
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    Quote Originally Posted by iProb8 View Post
    IMHO, the issue in the article does not help explain why, when I had 3G turned on, I was consistently dropping calls, in the same two places in the neighborhood by my house, as well as a spot near by office. For the two spots in my neighborhood, each was no longer than 100 yards (probably less than that) and both spots were within 1/4 mile of each other. I find it hard to believe that at those three spots, the dropped calls were due to power management problems.
    Power management is seems to play a large part in connection quality, but the again from the earlier radio test articles:

    "There can be differences of 10 - 20 dB by moving the phone half a meter, or if a car drives by."

    Radio propogation isn't as simple as being with in a certain radius of the cell tower, the question is, is the iPhone 3g worse than other phones on the same network and why, and 2.5g edge is technically a different network run by the same company in parallel.
    Last edited by Justin; 08-28-2008 at 01:59 PM.

  5. #25
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    If anyone still thinks the roughlydrafted article is a "crock of****" might want to dig into the UTMS technology here:

    Universal Mobile Telecommunications System - Wikipedia, the free encyclopedia

    which leads to:

    Radio resource management - Wikipedia, the free encyclopedia

    "RRM involves strategies and algorithms for controlling parameters such as transmit power, channel allocation, handover criteria, modulation scheme, error coding scheme, etc. The objective is to utilize the limited radio spectrum resources and radio network infrastructure as efficiently as possible."

    "Efficient dynamic RRM schemes may increase the system capacity in an order of magnitude, which often is considerably more than what is possible by introducing advanced channel coding and source coding schemes."

    Then to:

    Power control - Wikipedia, the free encyclopedia

    "Power control, broadly speaking, is the intelligent selection of transmit power in a communication system to achieve good performance within the system. The notion of "good performance" can depend on context and may include optimizing metrics such as link data rate, network capacity, geographic coverage and range, and life of the network and network devices."

    "Using a higher transmit power, however, has the following drawbacks:

    Overall power consumption in the transmitting device is higher. This is of particular concern in mobile devices, where battery life is reduced correspondingly.

    Interference to other users in the same frequency band is increased. In cellular spread-spectrum systems such as CDMA, where users share a single frequency and are only separated by different spreading codes, the number of users that a cell can support as well as the size of the cell are typically limited by the amount of interference present in the cell; increased interference therefore results in decreased cell capacity and size."

  6. #26
    Registered User equus's Avatar
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    Quote Originally Posted by Justin View Post
    If anyone still thinks the roughlydrafted article is a "crock of****" might want to dig into the UTMS technology here:

    Universal Mobile Telecommunications System - Wikipedia, the free encyclopedia

    which leads to:

    Radio resource management - Wikipedia, the free encyclopedia

    "RRM involves strategies and algorithms for controlling parameters such as transmit power, channel allocation, handover criteria, modulation scheme, error coding scheme, etc. The objective is to utilize the limited radio spectrum resources and radio network infrastructure as efficiently as possible."

    "Efficient dynamic RRM schemes may increase the system capacity in an order of magnitude, which often is considerably more than what is possible by introducing advanced channel coding and source coding schemes."

    Then to:

    Power control - Wikipedia, the free encyclopedia

    "Power control, broadly speaking, is the intelligent selection of transmit power in a communication system to achieve good performance within the system. The notion of "good performance" can depend on context and may include optimizing metrics such as link data rate, network capacity, geographic coverage and range, and life of the network and network devices."

    "Using a higher transmit power, however, has the following drawbacks:

    Overall power consumption in the transmitting device is higher. This is of particular concern in mobile devices, where battery life is reduced correspondingly.

    Interference to other users in the same frequency band is increased. In cellular spread-spectrum systems such as CDMA, where users share a single frequency and are only separated by different spreading codes, the number of users that a cell can support as well as the size of the cell are typically limited by the amount of interference present in the cell; increased interference therefore results in decreased cell capacity and size."
    Justin, please don't mistake my reply on the other post, reason why I say it was a crock is because of this>>>> wouldn't Apple have consulted at&t about their real technical workings and or specs of their network configurations? or wouldn't at&t have supplied Apple with some technical information of their tower configurations? I would think a device and or a radio chip manufacturer would design a product to fit the bill of a service provider so it is "totally compatible" with that system to operate seamlessly. I am sure the FCC specs and or GSM operating parameters are available to device manufacturers. IF Apple is exclusively going to produce a device to work ONLY on at&t networks here in US wouldn't it be "normal" to design a device that's compatible with that service providers technical specs?
    Hence my comment on that its a crock.........NOT about your post, I hope I did not come off arrogant or insult you, IF I did please accept my sincere apologies.
    Now, its a toss between DID Apple push this device too SOON? or did at&t not have a clue about the impact of large sales numbers and get their systems up to standards to accommodate these large numbers of iPhones pinging away at their towers? Seems to me that a while back if you recall the media jumping on Apple about how the iPhone "almost broke" an universities' wireless network and they all used the word "ddos" in vain? Remember the solution for that was FIX the system at that location and the iPhone was NOT the culprit. So, I think it seems to me both parties here might NOT have had any clue about final sales figures and somebody was caught sleeping at the wheel and now all are in "damage-control-mode".
    Funny it worked.....the last time! Now I am not sure what was working before they put a hole in my head !

  7. #27
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    Equus,

    I know your post wasn't directed at me, although it was somewhat implied that if they didn't go to college and where idiots for giving out that explaination that perhaps I am too for believing it. But don't worry as you know I don't shy away from a good debate and don't take anything said here personally.

    It's is just irksome to have you dismiss that possibility out right as though a kindergartner would understand that it was impossible. I just don't think it's that simple.

    From what I understand it's very plausible, they aren't saying the iPhone is "total incompatible" only that it has a flaw in it's power control algorithm. The fact that this flaw is fixed in 2.0.2 but if others on the same cell are using 2.0.1 or earlier can still affect your 2.0.2 phones performance goes a long way in explaining why AT&T went out of their way to get people to upgrade and why the first people putting 2.0.2 didn't see much benefit.

    It also seems completely plausible this slipped through QA, since it's based on heavy loading of cells with multiple iPhone 3g's, not that it's acceptable that it did.

    The source that gave out the info wasn't speculating and used the proper terminology in "UE" and "Node B" which you dismissed as BS but is part of the UTMS spec, and they where allegedly looking at real stats of less dropped calls as 2.0.2 started to take effect.

    So while it could be fabricated, it definitely isn't a bunch of BS, as a bad power control algorithm on the phone could cause exactly the issues being reported and explained in that article based on the technical information I posted here, do you agree?

  8. #28
    Registered User equus's Avatar
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    Quote Originally Posted by Justin View Post
    Equus,

    I know your post wasn't directed at me, although it was somewhat implied that if they didn't go to college and where idiots for giving out that explaination that perhaps I am too for believing it. But don't worry as you know I don't shy away from a good debate and don't take anything said here personally.

    It's is just irksome to have you dismiss that possibility out right as though a kindergartner would understand that it was impossible. I just don't think it's that simple.

    From what I understand it's very plausible, they aren't saying the iPhone is "total incompatible" only that it has a flaw in it's power control algorithm. The fact that this flaw is fixed in 2.0.2 but if others on the same cell are using 2.0.1 or earlier can still affect your 2.0.2 phones performance goes a long way in explaining why AT&T went out of their way to get people to upgrade and why the first people putting 2.0.2 didn't see much benefit.

    It also seems completely plausible this slipped through QA, since it's based on heavy loading of cells with multiple iPhone 3g's, not that it's acceptable that it did.

    The source that gave out the info wasn't speculating and used the proper terminology in "UE" and "Node B" which you dismissed as BS but is part of the UTMS spec, and they where allegedly looking at real stats of less dropped calls as 2.0.2 started to take effect.

    So while it could be fabricated, it definitely isn't a bunch of BS, as a bad power control algorithm on the phone could cause exactly the issues being reported and explained in that article based on the technical information I posted here, do you agree?
    Justin I totally agree with your post, I meant that some of these reporters use "techy words" that they have NO idea what the heck they wrote but just grasp onto a few sentences cause some" white paper" info they read or saw or were told, thats the BS I am referring to cause they just cause a panic-mode in people reading that and general public think OMG the sky's afalling..you know what I mean.
    YES a bad algorithm will definitely create transmission concerns, I AGREE.
    As tight-lipped as Apple and at&t are we as general public have NO idea what algorithm or architecture programming is done. I can "speculate" based on knowledge of these kinds of designs that it COULD be one of the reasons and I definitely cannot say THAT IS THE REASON. Anyhoo, its always pleasant to chat with people like you who know their stuff. Can you imagine if you and I started posting about NODES, latency effects of heat, wire sizes, hard-wire connections, contaminated core-copper lines, packet losses, true thruput, managing wattage during peak demand..........members here would call my wife and tell her to whack me on my cranium and put that hole right back where it was earlier......
    Funny it worked.....the last time! Now I am not sure what was working before they put a hole in my head !

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