Introduction to mobile phones - Part 1

Presented by Scott Kelley

With improvements in both telephone technology and hearing aid technology, more people with hearing loss are able to use mobile (cell) phones. Here's Motorola's Scott Kelley with great information on mobile phones and how to choose one.

This is part one of two parts.

For more coverage of this great convention, please point your browser to http://www.hearinglossweb.com/res/hlorg/alda/cn/2006/2006.htm

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We'll be talking about a variety of phones, and one of them is this phone, the benefits of which go to fight AIDS in Africa. It's part of a national program that includes many items, all of which are red, and all of which benefit the AIDS fight. We have designated one of our Razor phones to be one of those items. So when you buy our Red phone, you're helping to fight AIDS.

We'll also talk about some of the regulations that affect wireless communications. What does the term "HAC" mean? Then a bit about TTY devices, and then look at some tips and tricks.

Cell phones started as radios. And even today they are closer to radios than to phones. The original phones came out of our radio department. If you think about how a cell phone works, it has a radio transmitter, which goes out and talks to a tower via radio frequency. From there, it may hook into the landline system so the signal can end up at a standard phone.

Cell phones started out as analog devices. One of the things that means is that the phone is talking to the tower continuously. A digital phone, on the other hand, turns on and off very rapidly. Cingular or T-Mobile phones turn on and off over 200 times a second. And they spend more time off than on. That means that 3 to 8 people can use the same signal bandwidth that is used by one analog caller. That's one of the main reason the service providers prefer digital.

But why does a consumer want digital? Well, for one thing digital provides a lot of features that are simply unavailable using analog. Another advantage of digital is that it maintains basically the same signal quality as long as there is connectivity. This is different from analog, where the signal degrades as distance from the tower increases.

There are four air interfaces that are important. These are basically digital languages, and they use different programs to turn the analog signal into a bunch of ones and zeros.

One example is CDMA, which Sprint and Verizon use.

Cingular nad T-Mobile use GSM.

If you have your favorite Cingular phone and you walk into Verizon and want to keep your phone, but use their network, you're out of luck. It doesn't work, because different digital languages are used on the two networks.

Why is this so complicated? It's because the FCC allows these different technologies to compete with each other. In Europe they specified that everyone use GSM, so there you can keep your phone when you change services.

A third digital language is iDEN. These are the cell phones that do the walkie-talkie function through Nextel. That technology was invented by Motorola and is now used by Nextel. Sprint and Nextel have combined, so now Sprint-Nextel can sell you a phone that functions like a cell phone or a walkie-talkie. This is used by Sprint and SouthernLINC.

Q. If two people are talking on cell phones, why are they both billed?
A. The US is one of the few places in the world where there is no law specifying that the caller pays for the phone call. So the carriers here can bill both the caller and the receiver. The FCC is looking at a regulation called "Calling Party Pays". That would make it just like landline service, but it hasn't happened yet.

So that's the difference between digital languages, and the phones that use them.

All of these digital languages can potentially interfere with your hearing aid or cochlear implant. The buzz from the different phones can sound different, and various components within phones can produce different sounding buzzes, as well.

Another digital language is "3G", which is the third generation system. The problem with 3G is that everyone has their own flavor, and it hasn't merged yet. So that might happen in 4G.

Cell phones come in a variety of shapes, including standard looking phones, flip phones, candy bar phones, sliders, hybrid sliders (slides and flips) QWERTY devices, etc. And that's just the current Motorola product line.

The shape of the phone affects whether or not it interferes with your hearing aid or CI. Because there are so many shapes, if one phone doesn't work well for you, a different one may. Even devices that look very similar may be very different internally. And different phones have different features. So you need to decide what features you want and get that phone.

Wireless Accessibility Regulations

TTY Mandate - Wireless phones have to be capable of allowing TTYs signals to pass through to complete 911 calls. The 1G phones (analog) did this just fine. But the 2G phones came along and tried to convert the TTY tones to ones and zeros. The problem is that the equations that produce the ones and zeroes were developed for speech, and they don't work well on TTY tones. So the 2G phones didn't handle them well. They produced garbage, and the FCC said that the phones had to work with TTYs.

Section 508 - This is primarily for the government. This section says that items purchased by the government must be accessible.

Section 255 - This is similar to Section 508, and is sometimes referred to as the ADA for telecommunications. It says that you have to make telecommunications equipment accessible for people with disabilities, where it's readily achievable to do so.

Hearing Aid Compatibility (HAC) Mandate - You may see the chili pepper logo on the boxes. These have numbers that specify how compatible this particular phone is with hearing aids and telecoils.