What does “access” really mean?
Intel Labs held their “Trendspotting Summit 2013” on April 2nd this year. They invited World Bank Managing Director Caroline Anstey to speak.1 Her speech content was something that is generally removed from what we discuss during our work days. She opened by stating that 43 percent of the population in Nigeria is under 16 years old. This takes some thinking to discover what this means to our industry. Her presentation focused on four key changes, and all four were interesting. However, the third change, “The Mobile Revolution,” got my attention although was it was the least elaborated on. I think it was the opening statement, “Today more people have access to a mobile phone than a toilet,” that caught my attention. At first this seems almost funny.
Studies have shown that 75 percent of Americans use their phones while in the bathroom.2 So I guess this is overlapping access. OSHA recommends a minimum number of toilets per sex. For example, if you have between 111 and 150 employees of each sex, the facilities should have a minimum of six toilets for each sex.3 I know that in my workplace every one of those employees has a cellphone. So it is not surprising that most people will have more access to cell phones compared to a toilet. Anyway, this caused me to think about what it means to have access to a cell phone.
If you asked any one of my children what it means to have access to a cellphone, they would answer based on the cellphone being a smartphone. They very seldom use voice calls, basically only one of us parents ever calls them. So access is based on Internet connectivity, and the smartphone having the energy to maintain it.
We are back to a familiar issue, connectivity and the energy needed to maintain it. When the IPhone 5 was introduced, there was great expectation for connectivity time. For example, Apple indicated that the phone could provide up to eight hours of web browsing on the ATT LTE network. However, measurement by iLounge showed it was closer to six hours.4 The difference is more about having four full bars of LTE signal strength relative to only two or three bars. The lower signal strength is more typical of the user’s experience. Nonetheless, the users always think they should get the maximum hours of connected time.
To see what I actually have for battery life and connectivity, I decided to test my Android phone. I was only aware that my smartphone would need to be put back on the charger having started the day with a fully charged battery.
I configured my phone so that WiFi, GPS, and Bluetooth were turned off. I charged the phone to full, then removed the charger while the phone was in idle mode. After four hours, the battery was down to about 78 percent state-of-charge. Figure 1 shows the power percentiles for the operating functions. An interesting thing to me was that Deep Sea was consuming power when the display was off. Deep Sea is the bubble background on the display and I would have thought it would have been placed in suspend if the display is off. The next consumer, Screen, was also strange in that the screen was off except for the brief time when I stopped the experiment and record the information. The last thing to note is that if you add up the percentiles you get 102 percent.
Figure 1. Idle phone, screen off, 1 bar 4G
The next experiment was to test the phone while streaming a radio station. I returned the phone battery to full, started the radio stream, turned off the display, and unplugged the charger. In my office, I only get one bar and the phone operates in Edge mode instead of HSPA+. After one hour, I checked the battery. The battery had discharged to 84 percent. Figure 2 shows the power usage percentiles. Again, the screen shows considerable power based on it actually being off. The summary is that it appears that I can stream radio audio for about six hours.
Figure 2. Radio playing, Screen Off, 1 bar 4G
It appears there are areas of power management that can be deployed beyond what the phone currently does. One area seems to be associated with the display. My next step was to find the ever elusive 4G and 4 bars. I found a place and repeated the test. The results were that after one hour, the battery was at 81%, so the phone consumed more energy operating in 4G mode with 4 bars, which was surprising. The other notable difference was that the Android System was up from 2% to 15%.
Cell phone access is more than the possibility of connectivity. It also includes having enough energy to perform the desired communication. I imagine in developing countries where tower spacing is sparse and signal strength is low, phones will be at maximum power transmission leading to a high rate of battery discharge and short connected time. This limits the practical access. Just like the toilet, it is important to have functionality – as well as access.
Let me know your thoughts about achieving longer connectivity time with your smartphone. It seems there should be an app just like there is on the notebook that puts the phone in a particular profile based on what you need. The phone certainly has many adjustments and some are autonomous. But there is room for improvement so the user can quickly change the use profile.
For more information about this and other power topics, visit TI’s Power House blog: www.ti.com/powerhouse-ca.
- Living in a Changing World: World Bank Managing Director Caroline Anstey's Speech, The World Bank, Intel Trendspotting Summit 2013, April 2, 2013.
- IT in the Toilet: Study shows cell phones big in bathroom, by Amanda Kooser, CNET, February 1, 2012.
- United States Department of Labor, Occupational Safety and Health Administration
- iPhone 5 Battery Life Reduced Due to LTE Signal Strength, by Jim Tanous, The Mac Observer, September 27, 2012.