Cell Phones

Background

I've had a number of cell phones and if I can find the old ones will add them to this page.  The newest one is the Motorola Electrify 2 and there are a number of concerns in using various features hence the need for this web page.

Battery Failure

The early cell phones (Motorola Bag phone, Sony Erickson Cyber-shot) used replaceable batteries so a dead battery just required getting a replacement.  But starting with the Motorola X881 the battery is not designed to be user replaceable.  The Motorola Droid, the LG G6 also were replaced because of battery failure.

2023 June 30: New EU law to force smartphone makers to build easily replaceable batteries - a very smart rule as was the EU requirement that all devices make use of USB-C for charging ports.

Capacity

The first car telephones (Wiki:MTS, History-MTS, external web page) were limited to 25 channels, so if you lived in The Valley of Hearts Delight (Wiki) in the mid 1940's you had to stand in line to get one of the fully occupied 25 channels.  Today this system is called Frequency Division Multiple Access (Wiki:FDMA) but that term did not exist back then.  The main problem with a FDMA mobile phone system is the lack of channels but another is that each channel was just a 2-way radio and anyone with an FM communication receiver in the correct frequency band could listen in to the calls.

The first generation cell telephone system still used FDMA but added the concept of a geographic area called a cell.  The total geographic area was divided up into hexagonal areas (note: the intersection of the hexagons requires three antennas pointing 120 degrees apart) and the idea was that when a mobile phone crossed a cell boundary it would switch to an adjacent cell.  To avoid interference between cells the frequencies used by adjacent cells are different.  For example you would need to pass through 3 or 4 cells until you come to another cell that uses the same frequency plan as the first cell (Wiki).  This scheme allows reusing the same frequency at a reasonable distance between cell sites, rather than the MTS system where one frequency was used for all of the valley.  This increases the number of possible users but there is a limited number of users per cell.

There are a number of factors that go into determining how many users can be using a single hexagon cell at the same time.  The higher the frequency the smaller the cell size can be which translated to more users because there are more cell sites.  The total bandwidth of the cell site (number of channels times the bandwidth of each channel), the bandwidth of each user and the area of a cell are interrelated (Wiki: Cellular Traffic Capacity).  You might say there's no free lunch. There's a limit to how many users can be active in a cell and after than no new user can join that cell.  When internet browsing is added to a smart phone that requires more bandwidth so there can be fewer users in a cell.

It's my understanding (April 2016) that Silicon Valley (formerly Valley of Hearts Delight) has reached cell saturation.  One solution is to break up cells that are too dense by using micro, pico or femto cells (Wiki).  But this is a last ditch solution.  In my opinion in high population density areas, like Silicon Valley, using wireless technology for everything is a huge mistake.  There's fiber to the home (Wiki: FTTH) in the high density areas and people should use that instead of their smart phones.  You might think that another option would be to require a "smart phone" to use a nearby WiFi (Wiki) network instead of using the cell network.  But the same problem exists, i.e. there are only a limited number of channels (Wiki) so there's a real limit to how many people can use them at the same time.

The Cellular Traffic Capacity formula (Wiki: Cellular Traffic Capacity) tells you there's a density limit.  This means to serve a large number of users where each needs a wide bandwidth the size of a cell will be very small.   That can be done but at what cost compared to a fixed service like FTTH.  As the adoption rate for smart phones increases and/or the population grows the cell system is going to stop making economic sense for wide bandwidth applications (movies, internet).  Also the idea of passing text messages on the same channel used for voice does not make sense.  The old SMS worked by using the signaling channel that was used to coordinate the cell phone with the cell tower (Wiki).  This channel had a bandwidth much narrower than the audio channel of the phone and so would work with a weaker signal.  I was able to use SMS in places where there was no audio service in the late 1990s.  Note these old SMS messages did not cost the carrier anything since they were carried on the signaling channel that was active whenever a cell phone was turned on.  There was a limit to the number of characters that could be sent so that the signaling function would not be impaired. Note that Twitter is based on and still has this limitation (Wiki).

3906166 Radio telephone system, Martin Cooper, Richard W Dronsuth, Albert J Leitich, Jr Charles N Lynk, James J Mikulski, John F Mitchell, Roy A Richardson, John H Sangster, Motorola, 1975-09-16, - THE cell system patent.
YouTube: 60 Minutes: Great Inventions | 60 Minutes Full Episodes, 51:45 - May 23, 2010 Morley Safer the first dozen minutes on the cell phone.

Phones

Cell 2 Jack

2024 Jan - Have on order to allow connecting cell phone into KX-TA824 phone system in preparation for AT&T stopping all landline service in California (CPUC Proceeding A2303003).

This small box uses Blue Tooth to link to the cell phone and a standard RJ-11 jack for connection to a phone, or in my case to the phone system.
https://www.cell2jack.com/

Motorola Bag Phone

This was my first cell phone.  I had a custom made Yagi antenna made for it that along with a short mast and tripod support and low loss cable and adapters greatly increased it's range.

These phones are hackable in that you can access the inside and clone the phone for nefarious purposes.

Sony Erickson Cyber-shot K800i (Sony, White Paper) (Wiki)

Fig 1	Fig 2	Fig 3
Fig 4	Fig 5

Is a Tri-band GSM phone that uses a SIM Card (Wiki) that can be moved to another cell phone.
Networks: UMTS 2100, GSM (R99) 900, 1800, 1900, EGSM 900
Also uses a Sony M2 (micro SD) memory card (1GB).
Bluetooth, USB, IR connectivity.
Uses a single cell Li-Ion battery.

When the ear buds are connected they include an antenna for the built-in FM radio.
At the time this cell phone had a state of the art 3.2 mega pixel camera that could take still or moving images.  The still camera includes the provision to stitch photos to make a panorama shot.
I've used the SMS text messaging, but not the web browser.

Motorola Electrify 2 (XT881) (Same as Photon Wiki)

I live in the forest in Northern California were the cell coverage at my house is 1 bar at best.   I choose US Cellular as my carrier because of the best local coverage (Verizon has reasonable local coverage and at&t has poor local coverage) and the Motorola Electrify 2 because of it's weak signal performance.  The E2 is not as modern as the Electrify M, but that was a secondary consideration.  With just 1 bor (better called a dot) the phone will work, i.e. it will make and receive calls.

If the phone is left in the car (see installing Bluetooth into 2003 Mercedes-Benz C230 coupe) then it's battery will go dead in a day of non driving.  When driving it's connected to a cigarette lighter USB adapter so gets charged.  There are two fixes: (1) remove phone from car and plug into wall charger or (2) turn phone off if left in car (i.e. press and hold the on/off button till phone totally shuts down.

7 Feb 2013 - WIN XP Blue Screen of Death caused by Motocast or Motorola Device Manager.
The screen contained the following information:

DRIVER_IRQL_NOT_LESS_OR_EQUAL
*** Stop: 0x000000D1 (0x0036004D, 0X00000002, 0x00000001, 0xba26cc5b)
*** USBHUB.SYS - address BA26CC5B Base at BA268000.  Datestamp 480254D0

Starting Nero to burn a CD-ROM automatically started the installation of Motorola Media Manager and pressing CANCEL did not work.
When it finished restarting the computer generated the Blue Screen of death.
After power down and restart another lighter shade of blue screen showed the hard drive was being repaired.
Both Motocast or Motorola Device Manager have been removed using Control Panel / Add Remove Programs.
They were installed in an attempt to retrieve videos recorded on the phone.  The answer to that was to just connect the USB charging cable to a computer and extract the files.
But displaying the movies using the house WiFi did NOT work, probably because of not enough bandwidth.  Will try using a wired LAN connection soon.

21 March 2013 - The phone has transceivers for many frequency bands including 3G cell and WiFi.

Google Voice works through an internet connection to provide VOIP phone service.  With Google Voice running on a cell phone that has internet connectivity there's two ways Google Voice might work. 
1. Google Voice connects using the service provider's internet connection (a service with a monthly fee), or . .
2. Google Voice connects using the local WiFi connection.

22March 2013

With Google Voice installed on the cell phone part of the installation is to choose which service gets used when a number is dialed.
I've set it to ask me.  Now . .
When I press the green phone icon and dial a 7 digit number the phone does not ask, but uses the cell phone carrier.
When I press the green phone icon and dial a 10 (or more) digit number a pop-up window asks which service I should use.

Next to learn about forwarding a call to my cell phone to the Google voice number when I'm home, but still being able to answer calls to any number when I'm in my car.

5 April 2013 (Forced Power Down)

Phone non responsive to anything.  Pressing and holding the on/off button does nothing.  Connecting to a computer USB port does not register a new USB device.
The fix: 

Press and simultaneously hold <Up volume><Down volume><On/Off> for 30 seconds and then release all buttons.
This powers off the phone.
Press On briefly for a reboot.

Then in Settings:
Scroll down to About Phone and check for System Updates.
Now System Software Version:  982.118.14.XT881.USC.en.US  (was: 673.120.11.XT881.USC.en.US
Android version 4.1.2 (was 4.0.4)

Android Firmware Upgrade

15 July 2013 Movies upside down when viewed on PC.

The problem is that the Motorola Electrify 2 (and most cell phones) have an accelerometer that keeps the picture right side up when viewing it on the phone, but for this phone you need to have the USB connector pointing to the left in landscape mode to get a right side up movie out of the phone.  But I want to take movies in my car with the USB connector pointing to the right so the cable will reach the 5 Volt cigarette lighter adapter.  This is required so that the battery does not run out if taking a long drive.

The solution is to use Windows Movie Maker.  Import the video file and drag all of the movie down to the time line.
Then right click on the movie and select Special Effects.
In the Special Effects window scroll down to Rotate Image 90 degrees and add that to the effects list on the right two times, i.e. you will see rotate 90 degrees on two lines at the right.  Note:  If you select Rotate Image 1800 degrees it will both rotate the image and flip it left to right (a clock that was upside down to start will now be right side up but with 9:00 on the right.  By using two rotations of 90 degrees you correct for being upside down without the flip problem. 
Now save you movie to a new file.

PS to get access to the movie in the cell phone, connect the phone to a computer using a USB cable.  After the connection is made the phone will display:
USB Computer connection
If it does not you can slide the top bar down to show it.
Click to open a selection window with the options:
Mass Storage
Media device (MTP) - this downloads the Motocast software (not recommended)
Camera (PTP)
select Camera PTP.

Now on the PC under My Computer I see a drive called XT881 #2 and opening it I see a lower case "dcim" that has still photos and some movies and I see a upper case "DCIM" that has a "camera" folder with today's movies.
Select the movie(s) you wan to move and right click and choose Save In My Pictures.
Note:  This worked for a short video, but it's not working for the 1.81 GB video.
Solution:

Drag and drop the DCIM folder from the phone to the WIN XP Desktop.
Note:  the initial message at the bottom of the transfer window is Time remaining 2 hours 49 minutes, so I need to come back after 7:30 and see if it worked.
Note: the transfer window disappears after about a minute, but that may not mean it's not making the transfer.

Dec 2015 (Forced Re-Boot)

Phone will not turn on.  If it does turn on after the red circle M and less than a minute of the U.S. Cellular start up screen the screen goes black.
The fix:

With a charging cord connected:
Press and hold Volume Down and Power buttons for 30 seconds.
This is a forced  r-boot.

Memory Management

It turns out that when you take a photo or make a movie it gets stored in the phone's memory, not the SD card.  After awhile you will get the "Storage Space is Running Low" message.  This is about the phone's memory not the SD card.

To check on the phones memory press:
Apps (center 6 dot icon)
Files
DCIM
Camera
--------
Now to move these to the SC card press:
Utility Menu (3 dot icon)
Select Items
"0 Selected" and select "Select All"
in this case we want to move them so select the icon at the bottom that looks like a right arrow from a white box to a black box (Move) "

Next navigate to the destination, i.e. SD card by pressing: "3 selected" or however many you choose, and in the drop down menu press "SD card".
-------
Computer USB Path
With the phone on, connect it to a computer using a USB cable. 
DO NOT INSTALL THE SOFTWARE ON YOUR COMPUTER.  It caused the blue screen of death on my WIN XP computer.  If you have a different op system it may be OK, but is not needed for moving files despite what Motorola will tell you.

Wipe your finger from the top of the screen to reveal:
1) the USB debugging status, and
2) Connected as a mass storage (or other message related to how the computer is connected to the phone.
press this message to see the menu with three connection options:

Mass Storage - lets you transfer files on Windows or Mac computers.

Use to connect to the SD card, not the phone's memory.

"Connected as Mass Storage"
In My Computer I see MOT(K): as a drive that contains these folders:
.android_secure
DCIM
LOST.DIR
----
DCIM contains the Camera folder, which contains a test video I just made after moving all the files out of the camera

Media device (MTP) - Let's you transfer files on Windows or using Android File Transfer program on Mac.

"Connected as media device"
I don't see the phone using this on my WIN XP computer.

Camera (PTP) - Lets you transfer photos using camera software and transfer any files on computers that don't support MTP.

"Connected as Camera"
In My Computer I see XT881 #2 (not sure why the #2 since there's no #1).
This connects to the phone's memory not the SD card.

Dec 2015 battery dead on Motorola X881.  Replacement internal battery on order. 
Getting prepaid phone and as part of registering it will keep old phone number and cancel old contract.

X881 Battery Failure (was Replace Battery)

The battery in the Motorola XT881 is just behind the back cover.  The back cover is held on by clips around it's edge and by double sided tape on the rear of the battery.
Note in Fig 1 and Fig 2 that in the lower left corner of the battery label are + and - signs, indicating the battery polarity.
Connecting a voltmeter to those terminals and connecting a charging cable causes the battery terminal voltage to climb from 2.7 V to 3.1 and down to 2.8, what's going on???
In the lower right of Fig 3 the vibrator motor with a weight on both ends.

Fig 1 Battery & Tools from

Fig 2 Back Cover Removed

Fig 3 Battery Removed

Fig 4 Screen w/new battery

Note in Fig 4 above that there are a couple of triangles with ! inside indicating that the phone is not connecting to the U.S. Cellular network.  That's because I have stopped my US Cell service.
But the phone is showing a strong 3G Network connection and the normal very weak cell phone network connection.

When trying to place a call from the cell to my home phone, and selecting Use Google Voice instead of use cell network, an automated voice offers the options of 1 connect to my carrier or 2 make a collect call.
I was expecting the Google Voice to keep working, but because this is a US Cell phone that has not yet been rooted, it does not allow that.

SIM Card

Next, Where is the SIM card?  By calling U.S. Cell I was able to get the Unlock Code for my phone.  When a SIM card is inserted into the slot on the side of the phone it will prompt me for the unlock code.
But as of now the new battery is not working and the phone is totally dead, so working on that.

After the SIM card was activated on my LG-450 phone I discovered that there is no t-mobile reception at my house.  So moved my cell phone number to a Motorola XT1528.
But, T-mobile says that I can not change the registration once a phone number is assigned to the SIM card.  So need a new SIM and minutes to activate this phone and get a random phone number from them.

Hard Reset

This may be a way to cure the question mark (?) that replaced the battery icon after replacing the battery.

Hard Reset MOTOROLA Droid Maxx - two methods are shown:

Using Phone menu

1. From the screen of your phone, press the Menu button
2. Tap Settings
3. Scroll down and tap Privacy
4. Tap Factory Data Reset
5. Check Erase internal storage if you would like to erase all the data on the phone internal storage such as applications, music, movies or photos
6. Tap Reset Phone

Forced Power Down Method (see above for how to force a power down)
This does not make sense, since the 3 button method forces a power down.  Maybe a tap of the on/off button is needed to cause the BIOS boot?

1. Power up the phone by pressing the VOL UP and VOL DOWN Key together and the Power Key
   
2. The device will enumerate with different BOOT OPTIONS
3. Use the VOL DOWN Key to SCROLL and VOL UP Key to SELECT
4. Select Recovery
5. The device will start up with Motorola logo and power up to a little Android man logo with Exclamation mark
   
6. Press the VOL UP and VOL DOWN Key together at this screen
7. The device will display BLUE Text on a Black background
8. Use the VOL DOWN Key to scroll down and the Power Key to SELECT the option desired
9. In this case , press the VOL DOWN key till the Wipe data / factory reset is selected and press the Power key to confirm the selection
10. Use the VOL DOWN key again to select YES - delete all user data and press the Power key to CONFIRM
11. The device will then start performing the Factory Data Reset
12. Once the Formatting is complete , press the Power key to confirm a REBOOT
13. The message rebooting is displayed on the phone
14. The device will reboot and start the normal power up sequence. 

Warning! !Hard Reset will erase all of your data All described operations you are doing at your own risk

LG 450 Prepaid

Key features:

• Bluetooth to work with my car
• Same USB charging cable as Motorola X881
• Removable battery so it can be easily replaced with it goes bad (I have a replacement battery on order for the x881.

Battery: 531A-1, EAC61700101, LGIP-531A, 3.7 Volts, 950 mAh (about $3 each on eBay)

It seems like the battery goes dead in about a day when the phone is on at home and searching for a T-mobil network.  It probably would last much longer if there was a network connection here.

SIM Card

The T-mobil SIM card that came with the phone is good for 30 minutes.
There is no signal at all at my home, but when half way to downtown the phone syncs.
I tried to use the My TMobil web page to add minutes but their business model ASS-U-MEs that you always have a good connection.
Instead of waiting in the phone que the only call back option is to your cell number - this is worthless if you don't have any cell service at you location.
If yougo online to sign up for T-Mobile ID they send the confirmation text message to your cell number.  There's no provision to get that number via email and calling T mobil they tell me to go to my local T mobil store.
Time for a different carrier.

Locked to T-Mobil network and they will not unlock it until I've had it for at least one year.
But I can get another SIM card (and buy more minutes) and register the phone and have them adding a new number.

Motorola XT901

This is a phone very similar to the XT881 which has a bad charging circuit. 
But needs a SIM card to work and a mini size SIM is too big and a micro SIM it too small.
What's that about?  Maybe because it's marked U.S. Cellular that's the only service available?
13mm & 12mm are the slot widths.

Motorola XT1528 (Moto E 2^nd gen Verizon prepaid

This phone has a Verizon SIM card installed, but it can be removed by prying open the  bumper ring on the side opposite to the buttons.  There's also a SD card slot if you want to add more memory.
I have activated this phone with my cell number but it requires paying $30/month for unlimited voice and text, but no data.
The SIM card is 11.95mm wide x 14.96mm long
The open slot is 12mm wide, maybe for an SD memory card.

Motorola US Cellular prepaid.

Does not exist.

Motorola Droid Turbo 2

Verizon phone, asked for the phone with the best weak signal reception.  Either of the two Motorola phones was the answer.
The Droid Turbo 2 - has an almost indestructible screen.. The store demo is to throw the phone across the store.
It has wrist twist to turn on the camera and wood chop to turn on the flashlight.
Has NFC and wireless charging.

Signal Strength

Settings\About phone\Status\SIM status: shows:
Network: Verizon Wireless
Signal strength: -118 dBm 22 asu [readings change]
Cellular network type: 4G
Service state: Voice: in service / Data: In service
Roaming: Not roaming
Cellular network state: Disconnected
IMEI: number
IMEI SV: number

Settings\More\Cellular networks\Mobile network type: 1x= -104 dBm, 4G= -118dBm [readings change]

Failure of USB Data Connection ( July 2017)

I took a photo using the dt2 phone and then could not get it out of the phone.  After 3 days, with the help of Verizon tech support, I setup a VZW.com My Verizon web page and using the Cloud service was able to get the photo transferred.  But tech support was NOT able to get USB to work.  Today (2017 July 27) I purchased, from the local Verizon store, a ZipCord Micro USB Sync & Charge cable, p/n: ZKCB5P3BL14.  Now when the phone is connected via this USB cable the computer makes a noise and the phone shows up in My Computer.

Droid Battery Failure

March 2018 - difficulty connecting to car Blue Tooth - April 2018 total failure to connect to car Blue Tooth.  The problem was "battery expansion" which popped one corner of the bock open (and maybe destroyed the connection to the Blue Tooth antenna?  The Version store clerk said it was not safe.  But since I had not purchased the warranty it was not covered.  So got an LG G6 phone since the other options included things I did not want.

Battery Expansion	Notice back cover has gap at lower right corner.
Back Cover Removed	Copper wire coil is for wireless charging - which over charged battery causing failure.

LG G6 VS988

When I got home with the new phone I linked it to my car's Blue Tooth.  The next time I got in the care the phone connected to the car without me doing anything.  This is a much improved situation since with the Droid Turbo 2 it took a lot of fiddling with the Blue Tooth settings to get it to sync to the car.  Note this syncing to the car includes the car knowing all the phone numbers in the directory.

The initial problem I encountered was AppFlash (Verizon FAQ).

From home screen when swiping left to right a favorites screen appeared, which included Settings, for a fraction of a second then was covered by this AppFlash screen where the only option is to agree to have your cellular, Wi-Fi, Bluetooth®, GPS and sensor (gyroscope, accelerometer, light, magnetometer and pressure) information collected and sold.  I did not want to do that, but talking to two levels of Verizon support the only option seemed to be return the phone and get my money back.  But I found that by swiping right to left I could access "Settings" which was hidden by the AppFlash signup pop-up window.  Once in settings you can now get to"Application manager" and clicking on AppFlash (doing this from memory) there's an option to Disable which involves reverting to the stock version of the Android operating system.  This removed the sign-up window and AppFlash from the Applications manager.

A number of times, with the phone in my pocket, I've got in my car and driven off and the phone automatically syncs to the car.  Excellent, very different from the Motorola Droid Turbo 2 which required a lot of time trying to force it to synchronize.

Rings but can not answer

Just now the phone rang and a screen popped up that contained a Green button for answering the call.  But pressing the button did NOT answer the call.  Probably because there's only one bar of signal strength here where I live.  (See photo above)

GPS

The GPS is set to Mode: Battery Saving when new.  To get high accuracy: Settings \ Location \ Tap on Mode & select High Accuracy (GPS and networks) or Device Sensors only (GPS Only).

USB-C

The charging port used USB-C which to work no matter which way you plug it in. 
The LG G6 also supports USB On-The-Go (Wiki) that I used with an HF radio beacon to set the start time.  USB OTG is intended to allow adding things like flash drives, mice, keyboards or cameras to be connected to a smart phone.  The interface cable provides a USB-A socket like commonly found on laptop and desktop computers.

G6 Battery Failure

This is the third phone where the battery has failed.  See: Motorola X881 Battery Failure and Droid Battery Failure.  Now my LG G6 has a battery failure.
I live in a jungle (see video of bear in my back yard eating a deer) where there's just enough cell phone signal to ring the phone, but not enough to carry on a conversation.  I leave the phone on a wireless charger 24/7.  But the battery charging function in the phone should handle that since wireless charging is part of the phone's design.  What I'd really like is a phone with no battery that I could plug into my car.

Fig 1

Note: right end of battery has lifted up and the sticker is no longer attached on its right end.

LG G6 VS988 32GB Smartphone Verizon Unlocked

To replace the prior LG G6 I got one on eBay for about $100 with the auction title "LG G6 VS988 32GB Smartphone Verizon Unlocked".  All that was required was to use a paper clip to push into the SIM/Memory eject hole and move the SIM card to the new phone.  After charging the phone it called the account holder and asked if the movement ofth SIM card was valid.  On agreeing the new phone became active.  Note I did not attempt to transfer any information or apps from the old phone since there is only a very small amount of it.  I'll just re-enter the phone numbers manually and re-load the apps.  2021 Apr 17

2021-April 26 - I'm getting system updates pretty much every time the phone is powered up.  Now it's Update 20 (Aug 2020).
2022 Aug 20 - in order to download videos from a DJI mini 2 quadcopter into the LG G^ phone I need a lot of memory, so found the max micro SD card size is 2TB (Wiki: SDXC), but the most practical size is 1TB, larger or smaller costs more than around $130 for the 1TB size.  The DJI mini 2 from Costco came with a 32GB micro SD card installed.  See below.

Sim Card

Got a bunch of 32 GB MicroSD (Wiki: SDHC) cards for a Raspberry Pi so installed one of them in the phone.

Fig 2 MicroSD at left, nanoSIM card at right

Fig 3 nanoSIM card at left, microSD card at right.

No Service

Starting in 2023 this appears most of the time as I drive out from my house.  It did not do this before so maybe that was an update to the cell phone op system that caused it?  "No Service" shown in car. 

After trying a lot of things to bring back the connection the one that works, twice so far, is to just turn off the radio and turn it back on.
PS I have the display panel set to show the phone status so I can tell if the phone will work.

Wireless Charging

2023 I think the combination of wireless charging and being in a fringe location (1 bar) has led to killing batteries on a number of cell phones. I no longer use this.

This is the same technology as used on the Burton Induction cook top.  The modules to do wireless power transfer have been available for some time, but it's now a common cell phone technology.  The stand LED lights blue when connected to a source of 5 Volts using a USB micro cable (a very common cell phone charging cable) and when the phone couples to the stand the LED changes to green and the phone screen activates in wireless charging mode.
Flashing green LED means phone not aligned with any of the three coils, change phone position.
When the phone is fully charged the LED turns bright blue or maybe a blue green.
eBay seller housmile.mall - about $13.

Fig 1 Box barcode: MP-WS03BK

Fig 2 Comes with English instructions and USB micro cable

Fig 3 Charging Droid Turbo 2 Phone shown in portrait position, but also works in landscape position.

Does not work with an iPhone 5s when in a Lifeproof case.  The box says charging distance 4 to 10mm.  The case is 0.5" thick and the phone is 0.3" thick so the case only adds 0.2" (about 5mm) overall, which if most is on the back side might add 4mm, so borderline.
Also tried an Apple iPhone 6s, after removing the cover and the LED blinks green, i.e. wakes up phone, but in no position will charge it.

MIT App Inventor

This looks like a simple to use way to build apps for Android phones.

Near Field Communications (Wiki)

I got the Google cardboard kit for virtual reality that included NFC chip, but then found out that the XT881 does not support it.

This is just a new name for an RF ID system.
My Motorola Electrify 2 (XT881) does not have NFC capability.

There are add-on methods (SIM chip or memory chip with NFC) of getting NFC, but I don't know if they are a security problem as are charge cards that have NFC chips inside.
These can be read by someone near you while you are carrying them (without your knowledge that's happening).
To protect a NFC credit card you can put it into a wallet lined with aluminum foil.  While that will also work to protect a NFC cell phone, it will also prevent the phone from receiving calls.

NFC works in the 13.56 MHz ISM band (Wiki).  September 2018 I discovered NFC LED fingernail stickers that light up when a cell phone with NFC is passed near them.  They have not yet arrived, but I'm guessing there's a sense coil resonated with a capacitor that feeds a diode or diodes or maybe just back to back LEDs?
I'm pretty sure the LG G6 phone includes NFC.

Video on YouTube  showing a number of NFC chips on back of phone.
Notice that only chips near center are lighting up.
In order to get these to light up NFC needs to be turned on in Settings.

Car Mounts

My first attempt at making a video in a car was with the Apple iPod touch by hand holding it.  I was expecting to use up all of the 8 GB of memory very quickly because of the 1080p quality image, but only a small fraction of the memory was used.  But you can't hand hold an iPod and drive at the same time so some from of mount is needed.  Also there's no way to get the video out of the iPod in one go!

	The first mount I tried with the Motorola Electrify 2 (XT881) was a long stalk (goose-neck) type mount which was way too shaky to be used for video recording.
	The Sun Visor Cell Phone Mount is better than the stalk, but still has too much shaking for video. The Garmin Nuvi GPS is below the mirror on the left.
Mcally MGRIP2MP	The Windshield Mount may be stiffer. Testing will determine if that's the case. Note the phone MUST be mounted as shown with the USB cable to the left.  If the USB cable is to the right then videos come out upside down when transferred to the computer. Next need to make up a Power Pole bus for the phone, GPS and Radar Detector. so that there's not 3 cables coming down to the Cigarette Lighter Socket. Note:  This mount is rigid enough for making videos, but the phone needs to be all the way to the left to keep the suction cup out of the image.

Technologies

1G (Wiki)

The first generation cell system used the AMPS standard and was introduced to the U.S. in 1976.  AMPS is a first-generation (1G) cellular (Wiki) technology that uses separate frequencies, or "channels", for each conversation (Wiki: FDMA).  This system used narrow band FM modulation, the same as used by VHF & UHF two way ground radios (Wiki) like: police, fire, taxis &ectra.  These all could be heard using commonly available scanner radios (Wiki).  This lead to the Electronic Communications Privacy Act of 1986 (Wiki) and scanner radios with the 800 MHz cell band blocked.  The prior law was the Communications Act of 1934 (Wiki).

2G (Wiki)

IS-54 employs the same 30 kHz channel spacing and frequency bands (824-849 and 869-894 MHz) as AMPS.
Uses Time Division Multiple Access (TDMA) rather than separate channels like the analog AMPS system.
Retains the analog AMPS capability for phones that support it.

AMPS and D-AMPS were turned off around 2007.

3G (Wiki)

Introduced in the U.S. in 2002.  3G supports much higher data rates than did prior generations including live TV.

4G (Wiki)

"Real" 4G, which refers to all-Internet Protocol (IP) packet-switched networks giving Ultra Mobile Broadband (gigabit speed) access. 

"LTE is a standard for wireless data communications technology and an evolution of the GSM/UMTS standards. The goal of LTE was to increase the capacity and speed of wireless data networks using new DSP (digital signal processing) techniques and modulations that were developed around the turn of the millennium. A further goal was the redesign and simplification of the network architecture to an IP-based system with significantly reduced transfer latency compared to the 3G architecture. The LTE wireless interface is incompatible with 2G and 3G networks, so that it must be operated on a separate wireless spectrum."

Bluetooth (Wiki)

A 2.5 Ghz short range way for a cell phone to communicate with accessory devices like headsets or car audio systems (Mercedes Benz C230 upgrade to BT).

Note the car BT system not only allows making and receiving calls but also downloads the contact list from the phone into the car so calls can be placed from the list.
The problem is that the car display devices have a limited number of characters and don't show the phone number or type of phone (home, work, cell, etc.) so I need to assign new names in the cell phone so that when displayed in the car I can tell if it's a home, work, cell, etc. number.

There's an additional step in the car for assigning voice recognition to phone numbers.
I wonder if there's a way for the car microphone to feed audio to the cell phone and let the cell phone use it's voice recognition to dial phone numbers (hands free).

Standards

AMPS (Wiki)

The Advanced Mobile Phone System was the first generation analog system.

D-AMPS (Wiki) TDMA

This is a modification of the AMPS system to add digital voice in the bands that were also used for analog voice.  Same tower and phone frequency band as AMPS.

GSM (Wiki: GSM, GSM Phone)

Phones use SIM Card (Wiki).

Carriers

at&t Wireless (Wiki)
US Cellular (Wiki: US Cellular, CDMA,

Repeater

SpotWave Z1900 for the 1900 MHz band

Tower

Thisr cell site is built on a tall sign for a truck stop.  It's at 101 and N. State St.

Fig T2	Fig T4
Fig T1 Weather Station 101 & N. State Note old traffic camera has been removed.	Fig T3 There does not appear to be any provision for back-up power. Need to go and look to see if it's been upgraded since the 2017 fires and power failures.

Send email to Cell Phone

The email address is (areacodephonenumber)@{carrier dependent suffix)

Interesting Apps

SpyMeSat - info on public spy sats that can take photos of you.
Not an app, just a web page: Geospatial / Image Intelligence with TerraSAR-X

Bad Apps (Wiki: Bloatware)

My current Motorola (US Cellular) phone came with a bunch of apps that I don't want.  These apps want to get updates, but my phone almost does not work at home, so that's a problem.
BUT . . .  these apps are locked to my Android phone.

Mounts, Tripod &Etc

Ebay title: "Lusana Studio 1/4" Universal Tripod Mount Adapter with Cell Phone Holder" <$10.  Comes with cold shoe adapter. The swivel can be removed if you want landscape mode.

Cigarette Lighter to USB

My new cell phone strategy is to power off the phone when not in use.  That way maybe I can avoid exploding them, like has happened to the last three. So I had this adapter in my car so after the car is started (the Cigarette Lighter Socket is dead when the car is off) I connect the phone to the charger.  Today I connected the USB-A to USB-C cable to the phone in my pocket.  Then got out of the car to pickup my mail.  That destroyed the CL to USB adapter. 
It's marked as if one of the ports could supply 2.1 Amps and the other 1 Amp, but both ports are wired in parallel. I expect it's good for 0.5 to 1.0 Amps.
So here are some internal photos.

Fig 1	Placed the broken parts together. 8-pin chip is marked LC51 A/MC
Fig 2	Showing bottom of dual USB-A socket. I think both sockets are wired the same.
Fig 3	Here is the bottom of the PCB.

I have another on order that's compliant with Quick Charge specification 3 (Qualcom: QC3, SMB1352)
Quick Charge™ 3.0 technology: up to 4.6 A,
 (Wiki: USB Charging)

Related

Phones
Telephone Patents
Telephone Poles
Telephone Tool Kit
Telegraph
FasTrak Vehicle ID Transponder - is an active transponder, not an RF ID tag.
Key, Object & Pet Location Tags -
Spying on Cell (Mobil) Phones
Orion Electronics Ltd. Cellular Base Station ST616-CBS

Links

PRC68.com, Products I make and sell, Alphanumeric List of Web pages