Smart Phones and Signal Strength

Along with rest of the world, I have been looking on in stunned disbelief at how poorly Apple is dealing with the iPhone antenna problem. I am less troubled by the problem itself -- although it is not inconsequential -- since it has the smell of an unfortunate engineering compromise.

As this article indicates, signal attenuation is hardly unique to the iPhone. I can confirm that the Google (HTC) Nexus One does indeed have the same problem, as the article shows in its comparison. In a fringe reception area the problem can be severe, leading to the reported lost calls by iPhone users. Most urban users with an long-established carrier are unlikely to see the problem, or only intermittently when travelling. In my case the Nexus One is registered on Wind Mobile, and their coverage is poor, seemingly relying on fewer base stations ("towers") than Bell and Rogers to cover the city. Hopefully they are working on filling in those holes, but for now I am in a fringe area where the signal loss from simply holding the phone is catastrophic.

Fringe area performance is so noticable since with digital transmission technology there is a small signal strength interval between no signal and a perfectly clear signal. This wasn't the case back in the days of analogue technology (e.g. AMPS), where the degradation was more gradual rather than the modern phenomenon of sudden transitions between signal loss and acquisition. That is, you may not realize you are in a fringe area, and therefore prone to a dropped call, until it happens. This relates to the number of signal bars that are shown, and partly excuses Apple's reporting of more bars, since with digital transmission it isn't that big a deal provided there is enough signal to work with. In other words, if the phone works, for most people the number of bars is superfluous information.

Of course phone users do care about how many bars they get since it is one of the few ways they can judge how well their carrier is performing. In this respect, Apple's move to increase the number of bars reported (which has nothing at all to do with the phone's radio performance) annoys their customers. While not as serious as the speedometers in some early generation Japanese cars (early to mid-1970's Toyota Celicas are models that comes to mind) that consistently, and deliberately, read 10% higher than the true speed. The only purpose for cars and phones to do this is to mislead customers to an unwarranted favourable impression of the product.

CNET, for instance, ran some tests, and suggested that Apple might simply be juicing the signal display to make it look like its phone was getting good reception.

What I mentioned about an engineering compromise is worth comment. The insides of these big-screen smart phones are packed wall-to-wall with a lot of components. For best performance the antennas need to kept away from metal (many components and even the case) and coupling to or transmission through semiconducting objects (human body). The true situation is more complex than this short description, but it is enough to say that, under the many other constraints in place, placing the antennas around the outer edge of the phone is not unexpected. Avoiding coupling to the hand is best accomplished with distance, where even a few millimeters can make a difference, such as that provided by the rubber bumpers that Apple sells (I'm not aware of anything similar for the Nexus One).

Was Apple aware of this problem when they released the phone? I believe they were, and indeed it would have been extremely difficult for them not to know. But when it comes to large corporations and diverse priorities between engineering, marketing and management, it should surprise no one that engineering concerns about antenna performance would be acknowledged and set aside in favour of getting the phone into the market. After all, few people pay the slightest attention to the radio performance of a cell phone, preferring to focus on features such as camera megapixels, colour and song capacity, and the vendors respond accordingly. There are companies out there that do have a good reputation for radio performance: Motorola and even Nokia are examples that come to mind, but even they are inconsistent across the years and product lines so don't rush to them too quickly if that is what you want.

Apple will survive this road bump, probably even if they continue to obfuscate and mislead in their public relations. The brand is simply too strong and the majority of users won't even see the problem. However, a little dose of honestly wouldn't hurt them either.