An engineer’s perspective on something we take for granted… Cell Phones

The cell phone is a good example of why engineering objectives, cost and schedule are important. Ten years ago a cell phone was just a portable telephone. Motorola and Ericsson were the two big names in the industry. We went through several design (technology) iterations on the main phone (2G, 3G, 4G) with competing types of broadcast concepts (CDMA, etc.). For awhile Europe used one system, and the US another. So a phone built for the US was not usable in Europe and vice-versa. Then we settled on one type (standards!!) and now we all use the same broadcast technology.

The cell phone has been a rapidly evolving product. First, someone incorporated a camera – so all makers had to include a camera. New features came out every 12-18 months. Ericsson and Motorola fell by the way-side as Nokia became the big supplier. Now Samsung has taken over from Nokia. A GPS chip has been added. Blue Tooth (an engineering standard) allows other appliances (like your car) to work through a cell phone. The iPhone came out with all kinds of new applications (aps) including using maps for the GPS chip, managing your bank accounts, etc., etc. So Apple became a dominant force in the industry.

As an aside, the interesting thing about the cell phone is that marketing has been able to take the engineering capability and project it into products that consumers get excited about and are willing to purchase. This ability to marry the technology and its applications is why Steve Jobs (the visionary) was so successful in his later years (he learned from his earlier mistakes).

Product lifecycle
A cell phone has a useful life of about 15 months before it gets replaced with a new technology. Think about the engineering logistics … you start manufacturing today; three months from now, you reach peak production; 12 months from now you start scaling back; 15 months you stop production. I believe Apple sold about 100 million iphones last year.

Cost, Constraints, Trade-offs
A few words on Cost as an engineering objective. If you cannot make your product at a competitive cost, then it does not go anywhere. So cost puts constraints on engineering design. A new technology may be desirable, but not cost effective … for now. The next generation of widgets may incorporate it, however. Engineers have to make trade-offs during the design phase to achieve cost objectives. This is probably not something that has to be stressed in what you are trying to do at this point.

Product quality
Another STEM issue that is vital, but stays in the background is product quality. Until the 1980s, people used to buy a car knowing that they would accumulate a list of defects for 3 months or so, that the dealer would then have to fix. Now, we buy a car, drive it home, and only expect to see the dealer for oil changes.

Engineers have to design quality into a product … you can’t wait until you are in manufacturing to address quality. Today, we have design tools that address quality right from the start. Most people realize that engineers address product reliability and do testing and evaluation to assure reliability in the end product. However, most people do not realize that reliability is directly related to quality. A high quality product will also have high reliability and vice versa. Anyone who has purchased a refurbished computer, TV, or other electronic device will find this out …

What’s the problem?

  • Ask
  • Imagine
  • Design, Build
  • Improve

That’s engineering

  • constraint – a limitation or condition that must be satisfied by a design.
  • cellular technology – 2G, 3G, 4G
  • broadcast concepts – CDMA
  • standards

Engineering ideas

  • Constraint is a limitation or restriction on a design, something that the engineer must consider while making his design. Budget, for example, is a very important constraint on all projects, as all designs must be realistic regarding the amount of money that is available.