Charlie Calvert on Elvenware

Writing Code and Prose on Computers


Table of Contents

Mobile Technology

In the previous chapter I gave a broad overview of mobile technology. Without ever being specific about any one technology, I tried to give a sense of what a mobile device is, how it fits into the broader field of computational devices, and how it will likely impact individual users.


If you are going to connect to the cloud with a mobile device, there are dozens of possible protocols, but in the end, you usually have only three choices:

As a rule, access to wireless protocols are free, while access to packet data or roaming data can be obtained only if you pay money to a cellular carrier like AT&T, Verizon or TMobile.

Cellular and Wi-Fi.

You have undoubtedly heard a good deal of talk about 3G and 4G networks. These are cellular networks that allow you to send data to and from a mobile device. You can turn off your cellular network and still have phone coverage. You need your cellular network only if:

People get very concerned about the amount of data that their contract will allow them to transfer each month. Personally, I take the smallest amount my company will allow. I use cellular networks to transfer data only in rare circumstances, and when I do, I'm very careful about what I send back and forth. In particular, I using it almost entirely for maps and navigation.

Does this mean that I don't use data on my mobile devices? No, not at all. I'm sure I transfer a respectable, even unusually large, amount of data over my phone. It is just that I perform large transfers only when I am connected to a wireless network. In particular, I transfer most of my data either over my home network, or over the Bellevue College Network. I have a cellular contract for my phone, but my tablet works only over Wi-Fi. I'm content with this arrangement. I need to connect my phone to the network to transfer data from time to time, usually because I want navigation tools or to get email. My tablet, on the other hand, is not a tool I often use when on the go. I am content to wait until I am near a hotspot before I connect it to the network.

CDMA and GSM are two competing technologies for delivering cellular content. There is no particular technical advantage to using one or the other, but GSM is more commonly used around the world. As a result, if your phone uses GSM, then you will be more easily able to use it in foreign countries. There are always trade offs, but America is one of the few countries that has this problem, because it is one of the few places where the government has not been actively involved in setting standards. It is also one of the few places in the industrialized world where connectivity is spotty, and where prices are often prohibitively high.

In the US, only ATT&T and T-Mobile use GSM. The rest use CDMA. If you like to travel abroad, consider using a GSM phone so you will more easily be able to connect overseas.

In general, in Europe laws were passed to make phones more easily interchangable. In the US, companies fight to keep you locked into their system. In theory, the move to 4G and 4G LTE should end the grip of the big cellular carriers on your phone, but in practice, these companies are coming up with tricks that will keep you locked in.

4G standards are starting to be rolled out. This fourth generation of cellular communications is defined not by a particular technology, but by the speed at which the technology operates. There are currently two technologies, LTE and WiMAX, both of which are significantly faster than 3G technologies, but which do not yet reach 4G speeds of 1 GB per second (Gbit/s). WiMAX 2 and LTE-Advanced should operate at this speed and should be available by 2013.

Status Network
Status Network

In the screenshow of the network status page, can you find both places where it tells us that we are connected to 4G LTE network? Hint: Look carefully at the status bar at the top of the screenshot.

Frankly, I don't spend a lot of time thinking about these things. Fast Wi-Fi networks meet most of my needs, and even relatively slow 3G networks usually allow me to get the data I need when I am on the road and really need to pull down a map, a web page, or some email. Nevertheless, I'm sure I will adjust quickly enough when faster transfer rates become available -- so long as our cellular cariiers adjust rates appropriately to handle the speeds they offer. I have seen, for instance, cellular networks charge $20 a MB for transfers in "foreign" countries such as Canada or Mexico. Since some phones automatically upload pictures as you take them, a $10 trip over the border could quickly lead to the loss of your house if you start shooting some pictures or video while strolling for a few minutes on the wrong side of the imaginary line drawn between Washington State and British Columbia!

The upload speads for these technologies are generally one half of the download speed.

4G LTE and WiMax

The acronym LTE stands for Long Term Evolution. It is based on GSM/EDGE and UMTS. The technology first appeared in 2009 in Northern Europe, and in 2010 in the US.

Both 4G LTE and WiMax fail to fulfill the 4G specification. However, they have officially been allowed to use the name since they do represent a significant improvement over 3G. We are just now starting to hear about LTE Advanced, which might be a real 4G network.

LTE advanced would allow uploads of 1 GBits per second. The 4G LTE networks currently available allow 100 MBits per second.

Cellular and Money

On many Android devices, you will have a limit to how much Cellular data you can download. Let's be clear:


GPS is not the same thing as 3G, 4G or WiFi. For instance, my phone will give me accurate GPS readings even when I have data transfer (WiFi and 3G) turned off. However, you are probably used to having maps download when you look at GPS data. Nevertheless, if you know what to do with raw GPS (Lat/Long) data, or if you just want to record a GPS track, you shouldn't need to turn on either WiFi or Cellular data. If you turn on Airplane mode, however, then you will probably stop getting GPS data.

Cloud Maps

It might help to consider an example of the relationship between a mobile device and the cloud. When we use a navigation tool to help us to drive from one location to another, the information we use is typically stored in the cloud. Our computers connect to servers in the cloud, pull down a map, pull down information about streets and traffic, and plot a route between our current position and our destination.

Almost everything we see: the image of the map itself, the information about driving distance, the direction of one-way roads, the shortest distance between points, descriptions of landmarks -- all of it originates in a data store based in the cloud. It may not be a traditional relational database, but it is nonetheless data stored in the cloud.

It took little time for people to become attached to mapping and navigation tools, but once they caught on, they became very popular. If your phone could not connect to the cloud and pull down mapping down keyed to your current location, then the phone would not be nearly as valuable to you. We love our phones not because they are computers, but because they are computers connected to the cloud.


If you have been using a computer for years, and if you are used to a particular mail program, you have a number of hurtles to overcome before you can begin using your phone as a mail client. Here are some thoughts and ideas:

You can handle all your email communications over the phone. At first I wondered how people did this. Do some people have smaller fingers than me? Have they got some kind of mind meld with their phones? It turns out that it is just a question of desire. You just need to be willing to get good at using mail applications on a phone. You probably once put a lot of time into learning how to use a PC. You need to do the same thing with your phone. You may, in fact, have to be prepared to go through a significant learning process even to perform "simple" functions such as using a phone. It's all a matter of attitude.

One exercise that I have found helpful is to sit down in front of a computer with my phone in my hand. Open up my mail client on both the PC and the Phone. Try to handle all my mail on the phone. When I get stuck or confused, I go to the PC client and try to sort out what is happening. Perhaps I will find some kind of mail that I just can't process on my phone - at least not yet. In that case, can I mark it for later processing on the PC? If I have 100 messages, can I get through 93 of them on the phone, and handle the remaining seven later on the PC?

The Side by Side Strategy

I believe that it is not cheating to use your phone and your PC at the same time. At first, you may find that you did something on your phone but you are not sure that it really worked. If you performed the activity in the cloud, and you should be doing everything in the cloud, then you can simply open the cloud application you used on your device on your PC and check to make sure it worked. I often find that once I confirm that it is working, then I'm able to go back to my phone, and confirm the same thing on my phone.

Tablet and Phones

Which is better: a tablet or a phone? This is question that can obsess someone new to mobile devices. There are many arguments in favor of each platform:

Ultimately, the sad truth is that there are good reasons to own both a tablet and a phone. They each have their uses.

But come one Charlie, you must have an opinion. Which do you really prefer? If you had to choose, which would you take with you and which leave behind? The answer, perhaps not surprisingly, is not easy to frame properly:


As we move into the cloud, passwords becoming ubiquitous. It is not at all unusually for one person to maintain 25, 50, even 75 or 100 online accounts. No one can stay on top of that many usernames and passwords.

Even if you have an exceptional memory, there will come a time when the panoply of sites, password restrictions, and updated passwords will surpass your ability to remember the necessary details. One site has a limit of 12 characters, the next site doesn’t allow special characters; another site insists that you include special characters. Some sites force you to update your password at awkward times, other sites are so important to you that you feel compelled to update the password. Will you, at the same time, update all your 75 sites with a new password? Probably not.

There are several rules you need to consider when working with passwords:

Not all passwords are created equal. Suppose you choose the word enter as a password. Most hackers could break that password in less than 1/100th of a second. Suppose you choose enterT0wnN0w! as a password. It might take a hacker 26 million years to crack that password. It is not difficult to learn how to create good passwords. You just need to develop a few simple skills.

Here are some sites you can visit to help you learn how to design a robust password:

Of course, once you have created a good password, you need to have a system for remembering it. If you are using a mobile device, then you need to be able to remember it not just when you are at home, but when you are on the road. As a result, you probably want to use an online password tool such as LastPass, 1Password, or mSecure to help you track your passwords.

Writing information down in an encrypted document can also be helpful, but you need to be sure you can read the document even when you are on a remote machine. For instance, trying to read an encrypted Excel SpreadSheet is difficult if you are at a friend’s house and have access only to your Android phone.

Finally, it is possible that there are few sites that are so important to you that you would not trust the password to any third party, or to any encryption system. If you feel that way, fine, but you probably don’t need anything like that level of security on email accounts, technical sites, or social media accounts. Yes, you still want these sites to be secure, but a strong, frequently updated password and an encryption system that takes a few million years to crack is probably going to keep even a dreaded enemy, such as an ex-girlfriend, out of your Facebook account!

Display and Touch

We depend on our ability to manipulate a mobile device through touch. There are various types of displays that respond to touch.

hvga half vga - 320 * 240
800 * 600 svga, super vga.

My Machines

Samsung Galaxy Tab 10.1 - Specs

Samsung Galaxy Tab 2

The Galaxy Tab 2 is a good machine. Note, however, that it does not have as many features as the much smaller Galaxy S4. The Galaxy S4 costs a lot more, however, but the Galaxy Tab has a bigger screen.


Network for Galaxy S4: - LTE: Bands 1/4/7/17 - HSPA+/UMTS: 850/1900/2100MHz - GSM: 850/900/1800/1900MHz - Bluetooth - GPS - NFC - WiFi Direct



This is my old phone. I no longer own it. It has been replaced with my Galaxy S4.