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From: John Navas on 3 Jul 2010 21:51 On Sun, 04 Jul 2010 10:21:31 +1000, in <postings-0CB017.10213104072010(a)news.bigpond.com>, David <postings(a)REMOVE-TO-REPLYconfidential-counselling.com> wrote: >In article <622t261obucbj2tim2juellbdefd8o6gms(a)4ax.com>, > John Navas <jncl1(a)navasgroup.com> wrote: > >> "More suits filed in iPhone 4 antenna fracas" >> <http://news.cnet.com/8301-31021_3-20009625-260.html> > >Strange why people are just complaining about the new phone, my 3GS has >always dropped signal strength remarkably if I hold it with my hand >around the top half/ > >The difference is that it will go from 3bars to no bars depending on how >I hold it, and that is with a case on it It can be normal for signals bars to fluctuate even when not touching the phone or moving. Some phones, for example, will switch back and forth between the signal strength of home and foreign networks. This can be very frustrating when a foreign network has a good signal and the home network has a poor signal, but the phone is only allowed on the home network. -- Best regards, John If the iPhone and iPad are really so impressive, then why do iFans keep making excuses for them?
From: Jeff Liebermann on 3 Jul 2010 23:00 On Sat, 03 Jul 2010 15:05:02 -0700, nospam <nospam(a)nospam.invalid> wrote: >nokia dictates how to hold their phones: ><http://funsizebytes.com/post/745721120/instructions-from-my-nokia-2320> >here's another: ><http://i48.tinypic.com/x0xsi9.jpg> >there are plenty of others. True. Samsung has a sticker on some of their models warning users to keep their hands off the bottom of the phone. However, that wasn't my point. However, there's a difference between these phones and the iPhone 4. All of these phones will experience some reduction in signal strength (which causes a corresponding increase in TX power on the handset and cell site to compensate). Except in really really weak and marginal areas, I've never had a disconnect when grabbing the antenna on any of my phones (extendable or otherwise). Yet, the iPhone 4 causes a disconnect, which suggests that the signal loss is far more drastic than what has been observed on these other phones. >some other phones also use snr. there was an issue way way back with >sprint where people would complain that one phone showed the maximum >number of bars and another sitting right next to it had 1-2 bars. the >reason that one showed snr and the other showed strength. It varies by chipset. Both RSSI and SNR are available. I'm fairly sure the bar graph uses RSSI. I don't use bars. I use the signal strength and SNR (Eb/No) provided by the field test mode. <http://www.wpsantennas.com/pdf/testmode/FieldTestModes.pdf> In phone mode dial *3001#12345#* then press CALL. The Field Test Screen will appear. Select Cell Information. Signal Strength is on the top line after RX-. Frequency follows FQ and is based on the channel number (i.e. 100-200 is 800 MHz and 500-700 is 1900MHz). The top line displays information about the tower you are using. The lines below display info about your neighboring towers. I just tried the covering hand test with a Motorola RAZR V3M on Verizon. Signal level dropped -6 to -9dBm when covered by my hand. That's about 1 bar and maybe 2 bars drop. Incidentally, long ago, in a cell phone store long gone, I was standing in line waiting to ask some dumb question of the salesman. Ahead of me was the salesman and a lady looking at various phones spread around the table. Undecided as to which one to purchase, the salesman suggested picking the one with the largest number of bars. Over the years, the manufacturers and service providers have known about this effect, and tend to tweak the RSSI to bars conversion table to make more bars appear. My Verizon XV6700 would work just fine with no bars showing. Some other phones I've tried wouldn't work with 1 bar showing. >> My very unofficial conversion table from -dBm to bars: >> Bars -dBm >> 1 -102 to -112 >> 2 -94 to -101 >> 3 -87 to -93 >> 4 -77 to -86 >> 5 -38 to -76 >> tested on my VX8100. >according to anandtech tests, it's: -113, -107, -103, -101, -91, -51 ><http://www.anandtech.com/show/3794/the-iphone-4-review/2> What I did to measure mine was attach an external antenna to the phone, and bury the phone inside a home made shielded enclosure. I then used a step attenuator in the antenna line to adjust the signal level. The signal level in -dBm would change rather rapidly, while I had to wait perhaps 10 seconds for the bars to change. There was considerable guesswork involved, but I think I was close. Yet another dBm to bars table: <http://forums.crackberry.com/f3/change-5-bar-display-signal-power-dbm-26381/> >it also says: > > I can honestly say that I've never held onto so many calls and data > simultaneously on 1 bar at -113 dBm as I have with the iPhone 4, so > it's readily apparent that the new baseband hardware is much more > sensitive compared to what was in the 3GS. The difference is that > reception is massively better on the iPhone 4 in actual use. Oh rubbish. Just because it indicates 1 bar doesn't mean the signal is near the noise floor. Ask the author to supply some signal levels in dBm (and SNR) for a decent minimum usable level comparison. Incidentally, it's rarely the receiver in the handset that limits range and reliability. It's the receiver at the cell site, that has to handle overload from other sites, large dynamic range, and considerable multipath, while retaining decent sensitivity, that usually limits performance. The cell site xmitter can crank up the TX power to 1 or 2 watts (depending on band), while the typical handset can deliver maybe 100mw on a good day with a charged battery. Any more and users will be complaining that the battery doesn't last. >holding the pull-out antenna has an effect on my old cellphone, and the >instructions that came with it say not to do that. True. It has an effect, but it probably did NOT cause a disconnect. -- Jeff Liebermann jeffl(a)cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
From: tlvp on 3 Jul 2010 23:25 On Sat, 03 Jul 2010 14:40:59 -0400, Richard B. Gilbert <rgilbert88(a)comcast.net> wrote: > Justin wrote: >> Larry wrote on [Sat, 03 Jul 2010 14:27:22 +0000]: >>> Justin <nospam(a)insightbb.com> wrote in news:i0nbhl$pcn$1(a)news.eternal- >>> september.org: >>> >>>> data mining. >>> Precisely my point about the horrors of cloud computing..... >> >> yep, however this point had nothing to do with the cloud > > Who is responsible for the integrity and security of data stored "in the > cloud"? Why should I, or anyone, be willing to entrust his data to it? Case in point: the T-Mobile/Microsoft/Danger/Sidekick data-loss fiasco not that long ago. Has all that lost data been reconstructed yet? Cheers, -- tlvp -- Avant de repondre, jeter la poubelle, SVP
From: nospam on 3 Jul 2010 23:59 In article <qksv261j0m1ufu3n1mctmlml3ks4035737(a)4ax.com>, Jeff Liebermann <jeffl(a)cruzio.com> wrote: > True. Samsung has a sticker on some of their models warning users to > keep their hands off the bottom of the phone. However, that wasn't my > point. However, there's a difference between these phones and the > iPhone 4. All of these phones will experience some reduction in > signal strength (which causes a corresponding increase in TX power on > the handset and cell site to compensate). Except in really really > weak and marginal areas, I've never had a disconnect when grabbing the > antenna on any of my phones (extendable or otherwise). Yet, the > iPhone 4 causes a disconnect, which suggests that the signal loss is > far more drastic than what has been observed on these other phones. some users report call drops on the iphone 4 and others don't. > >some other phones also use snr. there was an issue way way back with > >sprint where people would complain that one phone showed the maximum > >number of bars and another sitting right next to it had 1-2 bars. the > >reason that one showed snr and the other showed strength. > > It varies by chipset. Both RSSI and SNR are available. I'm fairly > sure the bar graph uses RSSI. it depends on the phone. i know my old denso touchpoint displayed snr (and a fantastic phone). > I don't use bars. I use the signal strength and SNR (Eb/No) provided > by the field test mode. you'll be disappointed to learn that the iphone 4 has removed field test mode. anandtech managed to hack a level indicator back (but not the full field test mode) in by restoring a jailbroken backup which had some preference tweaked. > Incidentally, long ago, in a cell phone store long gone, I was > standing in line waiting to ask some dumb question of the salesman. > Ahead of me was the salesman and a lady looking at various phones > spread around the table. Undecided as to which one to purchase, the > salesman suggested picking the one with the largest number of bars. > Over the years, the manufacturers and service providers have known > about this effect, and tend to tweak the RSSI to bars conversion table > to make more bars appear. My Verizon XV6700 would work just fine with > no bars showing. Some other phones I've tried wouldn't work with 1 > bar showing. that's the thing, people want to see bars, but it really doesn't mean much. i've had successful calls with 1 bar and i've had drops with 5 bars. > >it also says: > > > > I can honestly say that I've never held onto so many calls and data > > simultaneously on 1 bar at -113 dBm as I have with the iPhone 4, so > > it's readily apparent that the new baseband hardware is much more > > sensitive compared to what was in the 3GS. The difference is that > > reception is massively better on the iPhone 4 in actual use. > > Oh rubbish. Just because it indicates 1 bar doesn't mean the signal > is near the noise floor. Ask the author to supply some signal levels > in dBm (and SNR) for a decent minimum usable level comparison. > Incidentally, it's rarely the receiver in the handset that limits > range and reliability. It's the receiver at the cell site, that has > to handle overload from other sites, large dynamic range, and > considerable multipath, while retaining decent sensitivity, that > usually limits performance. The cell site xmitter can crank up the TX > power to 1 or 2 watts (depending on band), while the typical handset > can deliver maybe 100mw on a good day with a charged battery. Any > more and users will be complaining that the battery doesn't last. the takeaway from that is there are many factors that contribute to a call drop, and also that it's really hard to do a controlled experiment. nevertheless, his experience is as valid as anyone elses, and he found reception to be better, and measured an increase in wifi strength when touching the antenna.
From: Todd Allcock on 4 Jul 2010 00:04
At 03 Jul 2010 23:25:55 -0400 tlvp wrote: > On Sat, 03 Jul 2010 14:40:59 -0400, Richard B. Gilbert <rgilbert88(a)comcast.net> wrote: > > > Justin wrote: > >> Larry wrote on [Sat, 03 Jul 2010 14:27:22 +0000]: > >>> Justin <nospam(a)insightbb.com> wrote in news:i0nbhl$pcn $1(a)news.eternal- > >>> september.org: > >>> > >>>> data mining. > >>> Precisely my point about the horrors of cloud computing..... > >> > >> yep, however this point had nothing to do with the cloud > > > > Who is responsible for the integrity and security of data stored "in the > > cloud"? Why should I, or anyone, be willing to entrust his data to it? > > Case in point: the T-Mobile/Microsoft/Danger/Sidekick data-loss fiasco > not that long ago. Has all that lost data been reconstructed yet? > Yes, about a week after the server crash. Of course that didn't make as many headlines as the loss did! ;) <http://www.betanews.com/article/Microsoft-takes-credit-for-resolving- Sidekick-data-loss-but-not-for-causing-it/1255618540> The real problem with the Sidekick's method of "cloud computing" was that there was essentially no local storage- the data was on the cloud and phone only, with no backup. A good cloud service, like Exchange, uses the cloud as an intermediary between devices, as well as a backup. I sync two mobiles and three PCs with my cloud service. If my provider crashes e or vaporates tomorrow, my data is safe in five locations, any of which can restore the data to another server/provider. |