Monday, September 24, 2018

Antennagate reduXS? If so, what can Apple and iPhone users do about it?

About 10 days ago, shortly after the Apple announcement event, I published an article that analyzed iPhone XS and XS Max RF performance as revealed in lab test measurements in the devices' FCC OET authorization filings.  Some of the lab test data raised potential red flags regarding the new iPhones' RF reception and transmission abilities in low signal strength conditions.  My analysis in that article concluded with...
...iPhone EIRP in the lab has not always been so compromised as it appears to be this year.  Real world RF performance comparisons when some users switch from the iPhone X and 8 generation to the iPhone XS generation, no doubt, will be interesting.
Well, over the weekend, more and more early adopters started getting their hands on their brand new iPhones, posting their real world impressions online.  While opinions on RF performance have varied from high praise to utter disillusionment, some anecdotal user reports and empirical signal comparisons at MacRumors forums and in more than one Reddit thread have been notable because they appear to corroborate how the aforementioned lab test results submitted to the FCC might extrapolate to less than stellar real world performance.

In many ways, this harkens back to iPhone 4 antennagate in 2010.  Without rehashing all of the details, iPhone 4 users just by holding the handset could bridge together unintentionally two antennas on the edge of the phone, thereby accidentally detuning both antennas and significantly degrading RF performance.  In response to the issue, Steve Jobs famously was misquoted as saying to users about the phone, "You're holding it wrong," which since has become a blame redirection meme unto itself.  Apple's official response was to provide all iPhone 4 purchasers with a free case to insulate the antennas from users' casual embrace.

But returning to the present, if the disappointing RF performance that at least some appear to be experiencing eight years later with iPhone XS and XS Max does boil down to another antenna issue -- weak antenna gain this time -- holding the handset differently or adding a case/bumper is not going to solve the issue.

Some have proposed that, if necessary, an Apple firmware update or two will sort this out.  Yes, iOS revisions and/or carrier updates can tweak the way the baseband modem interacts with wireless networks at large.  And, from an end user perspective, this can improve (or degrade) perceived performance.  However, what software cannot do is update physical qualities locked in during design and manufacturing.

An analogy for this could be the LCD or OLED display screen on your handset.  New firmware might improve image quality by way of adjusting gamma curve, color calibration profile, scaling algorithm, etc.  But that software update cannot change the screen size or pixel resolution -- both are physical characteristics.

In that spirit, if Apple acknowledges an issue and a fix, what software or hardware remedies could it propose?

Apple could submit to the FCC OET a Class II permissive change filing, which is an amendment to an original equipment authorization filing with additional lab testing to reflect a material change in the device.

Let us take a look at two possible Class II changes that Apple could implement, though for reasons to be explained, Apple probably would not pursue either one.
  • Increase conducted power via a firmware update
Conducted power is the input to the antenna, while radiated power (EIRP) is the output from the antenna.  But with increased conducted power, increased EIRP also would result.  This could help RF performance in situations in which the uplink hits its power limits before downlink reception drops below usability.

However, this is not a likely solution.  For an LTE device that operates in Power Class 3 (non HPUE) in a specific band, its target conducted power is 200 mW (23 dBm) +/-2 dB.  Similarly, for Power Class 2 (HPUE), target conducted power is 400 mW (26 dBm) +/-2 dB.  As noted in my previous article -- see quote below -- Apple already has applied conducted power somewhat liberally, pushing the +2 dB margin for conducted power across most bands.
...conducted power is not the issue.  The standard conducted power target of 200 mW (23 dBm) is +/- 2 dB.  And Apple is using the +2 dB margin to enhance its figures, pushing 250-320 mW (24-25 dBm) conducted power across many included bands.  This extends to band 41 HPUE, which has a standard conducted power target of 400 mW (26 dBm).  Again using the +2 dB margin, Apple has upped that ante to 500 mW (27 dBm).
Then, for visual reference, see a graph of iPhone XS Max conducted power.  Note that this graph is expressed in dBm instead of mW to reflect more directly the up to +2.5 dB boost Apple already has applied to conducted power above the standard 23 dBm and 26 dBm target levels, respectively.


Without HPUE across all bands, Apple has little, if any additional wiggle room to increase conducted power.  And, remember, bumping up conducted power helps only with uplink transmission.  It does not improve downlink reception.
  • Increase antenna gain via a hardware manufacturing revision
Increased antenna gain would cause increased EIRP -- with or without increased conducted power.  Additionally, as long as the same antenna arrays are used for both uplink transmission and downlink reception, improved antenna gain can assist in received signal strength, too.

This sounds like the ideal solution.  And, quite frankly, it is.  But for even more obvious reasons, Apple would be highly unlikely to go this modified hardware route.  This would be the nuclear option, so to speak, that would require some redesign and retooling of yet to be manufactured iPhone XS and XS Max units as well as possible replacement of extant phones for any dissatisfied users.  Instead, any antenna design changes probably will be saved for next year's iPhone generation.

So, what can iPhone XS and XS Max users do right now?

The new iPhones undoubtedly show some measured RF shortcomings compared to their predecessors and other comparable handsets.  However, the jury very much is still out on how much and how often this will affect typical use cases.

In the interest of investigation, many users already have jumped to comparing signal bars, though doing so is not very useful, since signal bars are just a coarse approximation of signal availability/quality and can be calibrated to almost any arbitrary standard.

Comparing speed tests also is not very useful for gauging weak signal performance.  Unless a speed test fails or produces very slow speeds due to exceedingly marginal signal conditions, devices with 4x4 MIMO reception -- such as iPhone XS and XS Max -- likely will exhibit higher download speed test results under most good to normal signal conditions.

Accessing Field Test to compare signal metrics (RSRP, RSRQ, CINR) across multiple devices actually is useful.  But this must be done with a watchful eye and solid understanding.  PCI, GCI, and EARFCN all must be the same in the same location to ensure that both devices are on the same PCC of the same site and sector.  Any difference among those matching signal characteristics eliminates a legitimate apples to apples comparison.  So far, Field Test reports are scant, though many more should be forthcoming as savvy users put their new phones through the paces.

Source: FCC OET

65 comments:

  1. This article just got linked at MacRumors. Your posts are getting linked on all the Apple sites.

    ReplyDelete
  2. Adding to the noise (sorry):

    Running speed tests on my iPhone Xs against T-Mobile LTE Cellspot V2 fed with gigabit fiber has been an interesting experience. The Intel Xs has only managed to pull a maximum of 72 Mbps downstream, compared with 120+ Mbps downstream with the Qualcomm iPhone 6s.

    Additionally found that the Xs could only pull about 220 Mbps from the nearest upgraded macrocell, compared with the 6s at 190 Mbps.

    ReplyDelete
  3. I was in an Apple store last night thinking about getting the X's as my family all have iPhones. I currently have an Android phone with qualcom modem. I decided to test it out. I connected to the same wifi that the demo devices are connected to and tested. Results were the same. Android device with qualcom was 4x faster then iPhone xs. I tested on multiple devices with the same results.

    ReplyDelete
  4. On AT&T in downtown Boston

    XS MAX 7+
    RSRP0 -112 -111
    RSRP1 -117 -109

    RSRQ0 -34 -30
    RSRQ1 -32 -28

    SINR0 -3.5 -5
    SINR1 -5 -2

    ReplyDelete
  5. Could this also have an impact on GPS signal? My iPhone Xs consistently has less confidence in the current location than may iPhone 8 Plus... still wondering why.

    ReplyDelete
  6. Yes, GPS could be impacted. Typically, a GPS antenna in a handset is collocated with a cellular antenna or a Wi-Fi antenna. If one or both of those antennas is low gain, that could extend to GPS reception. But on that note, pure GPS is a received signal only. So, GPS is not subject to transmitter testing submitted to the FCC. And that means that little, if any information on the location and performance of a GPS antenna may be included in an FCC OET authorization filing.

    AJ

    ReplyDelete
  7. So are all devices affected? I am planning on bringing my iPhone XS Max A1921 to the apple store and having it swapped out. After reading this article it seems futile.

    ReplyDelete
    Replies
    1. That depends on what you mean by "affected." What can be stated is that every iPhone XS Max A1921 has the same negative gain antenna array and Intel baseband modem. Whether one or both of those are the causes of some user issues remain unconfirmed.

      AJ

      Delete
  8. This comment has been removed by a blog administrator.

    ReplyDelete
  9. I live in vermont in a low signal area.
    I switched carriers and thought that might have been the issue but...
    We "upgraded" our 6plus and 6S to the XS And XS Max
    I now have a great camera that is sometimes a camera. I added a line do my 6plus is still operational.
    The 6 plus still works as it did. The new XS or Max not so much. In house Wi-Fi and calls drop won't answer -- I'm actually excited when it answers correctly.
    Incoming first answer it will say call failed,wait and it rings wait, wait a ring before picking up and it answers (sometimes) but caller has only called once.

    ReplyDelete
  10. Question, the LTE report part 1 from the FCC application for the XS Max shows an antenna gain table in section 5.5 (Maximum Antenna Gain)that shows columns for four antennae. However, only the columns for ant1 and ant2 are populated below a frequency of 1700 mhz. Does that imply the XS doesn't use 4x4 mimo on bands below 1700 mhz? In otherwords, the XS only uses 2 antenna with LTE bands 12,13,14,17 and 71?

    ReplyDelete
  11. Please read here!

    https://discussions.apple.com/thread/8548161?answerId=250081171022#250081171022

    ReplyDelete
  12. 바카라사이트 I have joined your feed and look forward to seeking more of your great post.

    ReplyDelete
  13. From one day, I noticed that many people post a lot of articles related to 온라인슬롯 . Among them, I think your article is the best among them!!I

    ReplyDelete
  14. When I read your article on this topic, the first thought seems profound and difficult. There is also a bulletin board for discussion of articles and photos similar to this topic on my site, but I would like to visit once when I have time to discuss this topic. 메이저사이트

    ReplyDelete
  15. I think a lot of articles related to are disappearing someday. That's why it's very hard to find, but I'm very fortunate to read your writing. When you come to my site, I have collected articles related to 크레이지슬롯 .

    ReplyDelete
  16. I totally agree with what you said. Thank you for leaving comments. I think more people should see the comments you wrote. Can I attach your post to my blog? I think many people will agree with you. 메이저토토

    ReplyDelete
  17. If you are looking for an author to write on your site, please contact me. I have some good posts that you might be interested in. I'm sure my post will be a good asset for me. If that's burdensome, can I quote your blog data on my blog? If you're interested, please send me an email. Thank you. 메이저토토

    ReplyDelete
  18. Thank you for creating a creative blog. It's amazing how you can write in such a creative way. Have you thought about another topic to post? I'm just working on a topic like that. I hope my blog helps you. 메이저토토사이트

    ReplyDelete
  19. Your ideas inspired me very much. 메이저토토사이트모음 It's amazing. I want to learn your writing skills. In fact, I also have a website. If you are okay, please visit once and leave your opinion. Thank you.

    ReplyDelete
  20. Online gambling service providers That answers all needs Excellent gambler 24 hours a day.
    토토

    ReplyDelete
  21. Please let me know if you’re looking for a article writer for your site. You have some really great posts and I feel I would be a good asset. If you ever want to take some of the load off, I’d absolutely love to write some material for your blog in exchange for a link back to mine. Please send me an email if interested. Thank you 먹튀사이트 I couldn't think of this, but it's amazing! I wrote several posts similar to this one, but please come and see!!

    ReplyDelete
  22. This is such a great resource that you are providing and you give it away for free. I love seeing blog that understand the value. Im glad to have found this post as its such an interesting one! I am always on the lookout for quality posts and articles so i suppose im lucky to have found this! I hope you will be adding more in the future. 토토사이트추천

    ReplyDelete
  23. This is an excellent website you have got here. There is one of the most beautiful and fascinating websites.
    It is a pleasure to have you on board and thanks for sharing.

    ReplyDelete
  24. This is a really cool article. I really envy people who can write well like you. The content of the text was well drawn in my head and was well understood. You seem to have great writing skills. I will visit often to read articles. I also want my website to be as great as yours. Thank you for your visit.
    토토사이트 코드

    ReplyDelete
  25. Antennagate reduXS is a new technology that claims to reduce the interference of cellular signals and improve the performance of Bluetooth devices. Apple has been working on a fix for this issue, but it has not been released yet. So, what can you do if you have an iPhone 6 or later? To avoid the antenna issues and other problems, try using a case with an external antenna.

    ReplyDelete
  26. This assistance is totally for nothing — we value our clients and anxious to meet their rules. Assuming that you need a blueprint for your undertaking notwithstanding the pay for a research paper genuine exploration, no issue. Simply request that a specialist remember it for your last solicitation and partake in your leisure time.

    ReplyDelete
  27. Appreciate providing these details, youre doing a great job with the site... 바카라사이트인포

    ReplyDelete
  28. Having read this I thought it was really informative. I appreciate you spending some time and effort to put this content together. 파친코사이트

    ReplyDelete
  29. What a nice article i found , i was looking it for a long time , i been searching it for so long now that i found out really help me.
    파워볼

    ReplyDelete
  30. This type of article will be able to think and analyzed to the readers thats leads them in a bright future.
    바카라사이트닷컴

    ReplyDelete
  31. I accidentally searched and visited your site. I still saw several posts during my visit, but the text was neat and readable. I will quote this post and post it on my blog. Would you like to visit my blog later? 메이저놀이터추천

    ReplyDelete
  32. That's a really impressive new idea! 안전한놀이터 It touched me a lot. I would love to hear your opinion on my site. Please come to the site I run once and leave a comment. Thank you.

    ReplyDelete
  33. I’m thinking some of my readers might find a bit of this interesting. Do you mind if I post a clip from this and link back? Thanks 먹튀검증

    ReplyDelete
  34. Very excellent information can be found on blog. 토토

    ReplyDelete
  35. Thanks for sharing informative, quality content. 스포츠토토

    ReplyDelete
  36. I appreciate your post thanks for sharing the information. 슬롯머신

    ReplyDelete
  37. Awesome post.Thanks for sharing.This is so nice. 토토사이트

    ReplyDelete
  38. I had a lot of fun at this Olympics, but something was missing. I hope there's an audience next time.안전토토사이트

    ReplyDelete
  39. You made some good points there. I did a Google search about the topic and found most people will believe your blog. 먹튀검증

    ReplyDelete
  40. This is also a very good post which I really enjoyed reading. It is not every day that I have the possibility to see something like this. 카지노사이트


    ReplyDelete
  41. I ve always been wasting my time, but I m here to read a lot of good information and good articles. Please update it every day. Thank you. 카지노먹튀

    ReplyDelete
  42. I will look at the posts posted on this site every day. This is because there is a lot of very useful information. 먹튀검증

    ReplyDelete
  43. I didn t know there was such a good place. I will visit often from now on. I hope your business thrives. 먹튀검증사이트

    ReplyDelete
  44. That s a good feeling about a good blog. I ll find out as I visit one by one. I think this kind of place will always be helpful. 먹튀검증사이트

    ReplyDelete
  45. To install Office Setup, go to office.com/setup website and enter the Office Setup product key.

    ReplyDelete
  46. Webroot is a subsidiary of Carbonite, which is, in turn, a subsidiary of OpenText, which provides enterprise information management software, including security software, to companies. For more information visit our website at webroot.com/safe

    ReplyDelete
  47. If you do not have a Norton account, to create an account from your web browser, go to norton.com/setup and click on Sign In. After that you complete your sign-up process.

    ReplyDelete
  48. This software includes various features and tools that help in automated preparation and filing of tax. TurboTax is very useful, as it simplifies the complex process. You need to install and activate TurboTax from turbotaxca.com/download when you purchase the software.

    ReplyDelete
  49. Download the driver or software for the printer scanner. To install your additional Canon driver or software go to the ij.start.canon link and follow the steps on it.

    ReplyDelete
  50. One of the biggest scandals in Apple history, "Antenna gate," celebrated its tenth anniversary this week. On June 24, 2010, Apple's iPhone 4 went on sale, sparking the Women Lingerie Satin Lace scandal. Customers who purchased the phone rapidly discovered that when held in the left hand, its bars vanished or calls were completely missed.

    ReplyDelete
  51. Hello, nice to meet you. You look very happy. I hope it's full of happiness. I hope we can do it together next time. Have a pleasant time.

    ReplyDelete
  52. Wir produzieren deutschen Führerschein ohne - EU MPU Führerschein. Wir entsperren Sie

    Im System. Wir speichern Ihre Daten in der Datenbank.

    kjop-forerkort-uten-eksamen.

    comprare-carta-conducao.

    f-a-qs.

    comprare-la-patente.

    echten-fuhrerschein-kaufen.

    f-a-qs.

    f-a-qs.

    fin.

    comprare-la-patente.

    kontakt-oss.

    ReplyDelete
  53. This is very interesting, You are a very skilled blogger. 메이저사이트

    ReplyDelete
  54. I couldn’t resist commenting on this article. Wonderful post! 사설토토

    ReplyDelete

  55. This is so much hilarious blog, Anyways thanks for posting ideas.
    한국야동

    ReplyDelete
  56. แต่ถ้าหากเจอแจ็คพอต pg slot รับรองว่าได้จับเงินหมื่นแน่นอนเลยค่ะคุณนั้นสามารถ เล่นสล็อตออนไลน์ pgslot ได้บนมือถือ และสามารถที่จะเล่นได้ทุกที่ทุกเวลาเกมสล็อตบนมือถือ สล็อต
    pg และมีให้เลือกเล่นเยอะมากมากกว่า 1,000 เกม เล่นแล้วไม่มีคำว่าเบื่อ เล่นได้เพลินๆ เล่นแล้วติดใจอย่างแน่นอน สามารถที่จะ ทดลองเล่นสล็อตฟรีได้อีกด้วย สล็อตออนไลน์ ถือว่าเป็นสิ่งที่ประหยัดเงิน ค่าที่พัก ค่ากินและ ค่าเดินทาง กว่าการไปเล่น บ่อนคาสิโน ต่างประเทศ เราสามารถที่จะเล่นผ่านมือถือเราได้ สล็อตpg ง่ายมากเลย

    ReplyDelete