The iphone 4 handheld signal attenuation problem from the perspective of user experience

The IPhone 4 has been on the market for a week, with the most attention being paid by consumers and the media in addition to its frantic sales speed. A design so sophisticated mobile phones, even the user to change the holding mode to normal use, this result is indeed embarrassing. First of all, it should be explained that the state of the signal attenuation in hand is not iPhone4 original, many mobile phones will have such a situation. In recent years, most mobile phones have hidden the antenna in the phone's internal bottom or top, users in the ordinary holding mode is difficult to affect it, it is rarely noticed.

So the problem is in Apple's "innovative" external antenna design. In addition to the fuselage frame function, the IPhone 44-week http://www.aliyun.com/zixun/aggregation/2558.html "> Stainless steel border also acts as an antenna, and is divided into two segments." The left half of Bluetooth, WiFi, GPS antenna, the right half of the 3G/2G mobile phone network antenna. The black "gap" on the left side of the phone is the dividing point of the two-segment antenna. The problem is here, when the iphone 4, especially the left hand grip, the body will act as a conductor, the two-segment antenna conduction, resulting in interference, affecting the phone reception.

As early as the iphone 4 was released, a lot of people in the communications industry had a hunch. It was expected that Apple could avoid this problem by applying a layer of insulating material to the stainless steel frame. Unfortunately, Apple did not. Now that the product is on the market, Apple's answer is to either change the handheld or buy a phone sleeve that can act as an insulating layer.

The issue was thoroughly tested in the AnandTech website's evaluation of the iphone 4. We know that almost all mobile phones use columnar bars to display signal strength, which is what we often call a "few lattice signals." But because the definition of each signal is very different, this method of measurement has no meaning for real problem solving. As a result, the tester took the iphone 4 and the 3.1.3 firmware that accurately displayed the signal strength, the iphone 3GS, repeated tests in the same signal environment, and finally gave a more accurate figure of the meaning behind the iphone 4 signal bar.

As you can see, from the limit -51dbm of the UMTS 3G network signal to -91dbm,iphone 4, it will be displayed as a five-cell signal. And then the spacing will be very small, -91dbm to -101dbm four, -101dbm to -103dbm to three, -103dbm to -107DBM for two, -107dbm to -113dbm for a grid. If the signal is below -113DBM, the call and data connection will definitely be interrupted.

According to the test, holding the iphone 4 will cause the signal to drop by up to 24dB. The problem is that it's also a 24dB drop, and there are two distinct effects on the user experience:

When you are in the vicinity of 3G base station, the signal is good between -67dbm to -51DBM, even if the fall 24dB, still in -91dbm above, the mobile phone still show as five grid signal, call, the Internet is almost impossible to be affected.

And if your signal at this time for -89DBM, although the display is also five grid full signal, but if the hand down 24dB, will be a moment below the -113dbm bottom line, the phenomenon of disconnection. It's already a four-cell signal, let alone. And since the cell phone display signal lattice has a delay of about 10 seconds, you will see the signal from the five grid down again and again until lost connection.

The following is the handheld impact test results on the iphone 4, iphone 3GS and Google (HTC) Nexus one, under the same network conditions:

As can be seen, the IPhone 4 in the handheld state of the signal drop is indeed higher than other models, but with the addition of insulated phone sets, the situation has been similar to other models.

So is Apple claiming that the newly designed iphone 4-day signal reception has improved, cheating consumers? The answer is also negative. According to the test, the iphone 4 does make progress in signal reception compared to the iphone 3GS, especially in weak-signal conditions such as calls and data transmission stability. For example, here's a screenshot:

The IPhone 4 is still in a three-party conference call when the 3G signal has a -113dbm minimum (one grid), while the network data transmission speed test is still in progress. There was no disconnection and no network drop, which was impossible on the previous iphone 3GS.

The problem seems to have been largely clear, Apple can in the future software upgrades, the design of the number of signal lattice to modify, so that the coverage of the five-grid as far as possible, to give users a clearer signal strength awareness. However, this does not solve the fundamental problem. To completely quell the user's complaints, Apple either needs to add a layer of insulating film to the iphone 4 border in the manufacturing process, or it needs to drastically reduce the price of the bumpers (which is sold at $29), or even give it directly.

Today, however, a new view has been raised that the IPhone 4 signal problem may not be related to the handheld approach, but also to the SIM card. This is even more bizarre, saying that the iphone 4 has a signal problem because the SIM card contacts are connected to the Cato metal frame.

It is said that the user initially also appeared in the hand after the signal attenuation or even disconnection trouble. In consultation with Apple customer service, he will mobile phone SIM card out, soon after reloading, the problem is solved. After repeated thinking, he found the problem was on the SIM card. As shown in the following illustration, the SIM card's contacts and the Cato frame are connected to the border antenna, which may be the cause of the signal problem.

Since the iphone 4 uses MicroSIM cards, many users need to cut their own cards to use. The slight error in cutting the card may lead to this problem. This also explains why the signal problem only occurs in a subset of the users, while other users do not have a signal drop even if their left hand grips the phone.

Some users have successfully reproduced this problem and solution by pasting a small section of insulating tape into the link between the Cato and the contact point. But there are other users who say the method is completely useless, and the IPhone 4 signal puzzle may have to continue.

This is clearly not the phenomenon Apple is willing to see. Apple is looking to recruit up to 8 wireless technology engineers for the design and testing of antennas in Apple's official website. With the help of these new recruits, I believe the problem will not be repeated next year.

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