Why Are My iPhone Text Messages Sometimes Blue and Sometimes Green?

Lately I've been getting this question a lot. Here's what's up.

Green messages on your iPhone use a voice text protocol called Short Message Service (SMS). SMS was developed way back in 1982 and designed to run on voice networks using a separate channel used for signaling. Technically SMS was easy to implement and, with the popularity of mobile phones, it became very popular really fast. Messages are limited in length 160 characters and as a result many of us have learned to abbreviate words using text-speak shorthand.

iMessage is different. It's Internet Protocol (IP) based and does not require a voice connection. You can use IP based text services like iMessage on cellular data networks along with WiFi networks and your computer.

Now here's the big advantage - you don't need a text message plan to send and receive iMessage based texts. You do need some kind of text message plan to send and receive SMS (green) messages.

When are messages green? Here's a few common scenarios:

1. You or your friend have not updated your iPhone to iOS5
2. You or your friend are not registered with Apple iMessage. 
3. You or your friend are in a place where there is no cellular data signal but there is a voice network signal.
4. You send a message to someone not on the same network as you and only one of you has an iPhone. For example, you've got an AT&T account and your friend has a Verizon Wireless account. If you both have iPhones and both have data connections iMessage will work cross-carrier. 
5. You're on the same network but one of you has iMessage turned off. To turn iMessage on and off on your iPhone use Settings -> Messages -> iMessage On/Off

Is SMS sticking around? Not for long with "free" services like iMessage and this is rapidly becoming a problem for the providers. SMS has been a huge cash cow for wireless providers earning an estimated $114.6 billion in 2010.

Sprint 4G LTE Comes to Massachusetts and Texas and Kansas.....

It's been a crazy month with a major National Science Foundation proposal submission deadline last week. To everyone who submitted (including us) - Good Luck!

I've been catching up on email the past few days and finally have time for a quick post. I've written here in the past about Sprint's planned and inevitable migration from WiMAX 4G services to LTE..... well it started today: 

Sprint Brings 4G LTE to Customers in New Bedford/Fall River, Mass.

Sprint Brings 4G LTE to customers in Hutchinson and McPherson, Kan.

Sprint Brings 4G LTE to Customers in Wichita Falls, Texas

And they're even starting in Chicago:

Sprint Brings 4G LTE to Customers in Chicagoland

Sprint's plans are to get 115 locations up and running LTE in the next few months. Good news for Sprint and customers. Watch for ads/commercials to start.

Attenuation in Fiber Communications Systems

I'm teaching a fiber optics communications course this semester and - like just about every communications course - we started out talking about attenuation.

Attenuation is just a fancy word for loss. In any communications system you've got a certain amount of signal strength going in and a certain amount of signal strength coming out. If there is no amplification in a system there is always going to be loss and the output signal will always be weaker than the input signal.

In fiber systems attenuation is caused by three things:

1. Absorption - Glass, whether it is fiber or the windows in your house, will always absorb a small amount of light going through it. The amount depends on the wavelength of light and what the glass is made of.
2. Scattering - Atoms in glass cause a certain amount of scattering of light and scattered light will not emerge at the output.
3. Leakage - Light will leak out of fiber, especially if the are a lot of bends in the fiber.

Fiber manufacturers typically provide specifications for all three of these, along with total attenuation per kilometer.

One of the primary goals in any communications system is to keep the attenuation to a minimum. Even so, there will always be a loss in signal intensity when comparing output power to input power. Calculating attenuation in a system is pretty simple. Attenuation is cumulative so basically you just add up the signal loss for each component in the system. Here's an example:

Question: A 50 km fiber run has been spec'd at 99% transmission per km. What percentage of light will emerge at the output?

Answer:

The fiber run is transmitting 99% per km so after the first km 99% of the input signal will be available, after the second km, 99% of what's left after the first km will be available, etc. So we can say:

60.5% of the original input signal strength will emerge at the output.

When Will Batteries Last A Week?

Like many of you, I'm constantly on the look-out for wall outlets. Meetings, airports, etc - if there is an outlet, I'm trying to find it. I've always fantasized about not having to carry around a charger. Wouldn't it be nice to get 40 hours out of a battery before having to recharge? It sure would! When will it happen? Lenovo has an interesting infogram out that take a look back and look forward when it comes to battery life technology.



Looks like we've got about ten years to go!

Memories of September 11, 2001

I first published this four years ago.

I was walking into the office when our technician told me a plane had hit one of the towers - he said "they think it was a small plane" and I did not think too much about it. 20 minutes or so later I was in a meeting and the same tech came in saying it was an airliner. We all left the meeting and turned on a small television in our lab. I also made sure I had a computer close by so I could watch email.......

At the time we were running a national listserv for a large group of community college faculty and administrators involved in a Working Connections grant with Microsoft and the American Association of Community Colleges (AACC). I've pulled out a few emails that came to the list. Here's one of the first from Mete at Borough of Manhattan Community College (BMCC):

11:50 AM, 9/11/01

It is chaos here, but everybody at BMCC is OK. We are closed for the day and the roads/subways to in/out of Manhattan are blocked. I am in Brooklyn (home) now and the sky is dark from smoke/ash/soot. I have a feeling it is going to take a long time to recover from this one.
Hope all is well with everyone around the country,

Mete

BMCC is on Chambers Street, next to ground zero and a college building was damaged from the attack. Mete was on the subway on his way in when the attack started and I believe he walked home to Brooklyn.

Here's a reply message from Lynn at the AACC in Washington, DC::

12:05AM, 9/11/01
We are ok here, but our office is closing so people can try to get home. The smoke from the Pentagon is visible from our 4th floor conference room. Most of the federal offices have now closed, a couple of subway stations near the Pentagon are closed, the streets are crowded with people driving and walking home from downtown offices, and cars with sirens go by every 5 minutes or so. Folks who live near Capitol Hill are sticking around the office until things calm down in that part of town.

Lynn

A flurry of emails went back and forth during the day from people all around the coutry. We were all worried, frustrated and upset about the attacks and our friends in New York, Washington and Pennsylvania. Here's a sample of the response from Paula at Richland College in Dallas:

11:50AM, 9/11/01
Thank you both for taking the time to provide us with an update of your safety. Our prayers are with you and all Americans during this tragedy. As in other states, thousands are donating blood. A major sports arena in Dallas has been setup as a blood donation facility. Churches are conducting special services. Please assist us to remain informed as to organizations/drives that are established that will provide direct support.

Paula

This came from Chris at the Fashion Institute of Technology (FIT) in New York City a few days later:

10:50AM, 9/14/01
FIT is safe and sound and open for business but few classes are running normally. It is hard to describe the experience of walking south on Manhattan's avenues and seeing a column of smoke where the World Trade Towers should be. When the wind shifts, the smell of the fire comes to Chelsea with a light dusting of the cement that is ankle deep a few blocks away.

We are glad to hear that all are well at BMCC and in Washington.

Chris

Here's a followup from Mete that was also sent on September 14:

12:36AM, 9/14/01

The building that we (CIS) dept was suppose to move this Sept., (but did not because of delays) is quite damaged. They are using our main building as command/triage/morgue center. We will be closed until the end of next week. The cleanup is going very slowly and there is very limited access to downtown Manhattan.

The subways are not running and all the outer borough are choked with traffic with people bringing their cars and parking them as close to Manhattan as possible. The air quality is bad, there is possibility that some more buildings (including our own that was next to a collapsed building) may come down aggravating the situation.

There are a number people that I know, with families, that perished in the bombings (we were going go to a 10th bday party this weekend, but the mother is missing - what do we do now ??) from my daughter's school and our neighborhood. But they are defiant, and most of the businesses try to operate as usual with a backdrop of surrealism...

Thanks for all of your e-mails and good wishes. We appreciate it and find comfort in them.

Mete

Hundreds of emails went back and forth over the next few weeks on the listserv. I've saved them all.

eReaders Becoming Niche Market Players?

I've always been a fan of the Kindle and other eReader type devices, especially when compared to bulkier and heavier tablets that are difficult to view in direct light conditions. Lately though, I've been wondering how long eReaders would continue to exist as tablets become lighter and smaller with better displays. Well, I just read an interesting study from ABI Research titled eReaders and the Digital Publishing Market that takes a look at where the eReader market is going.

Here's some details from the ABI report:

• Eleven million eReaders are projected to be shipped globally in 2012, down from a peak volume in 2011 of 15 million devices.
• The growing popularity of media tablets along with declining US “baby boomer” population and lack of organized digital bookstores outside of the US and Western Europe will reduce the eReader opportunity over the next five years.
• Despite the average tablet selling for more  than $465 as a result of Apple’s dominant market position, tablets are expected to outsell eReaders 9 to 1 this year. 
• Over the next five years, annual eReader shipments are projected to drop by a compound annual growth rate (CAGR) of 6.1%. In contrast, global media tablet shipments are predicted to increase from approximately 102 million annual device shipments in 2012 to nearly 250 million in 2017.

All bad news for eReaders. Well, not so fast.... the report continues... However, eReaders maintain advantages over media tablets for reading purposes. Electronic paper (ePaper) displays are able to better replicate the print reading experience and are usable in direct sunlight conditions unlike LCD technologies. The eReader battery life of weeks between charging is significantly greater than the media tablet. And of course, eReaders are priced significantly less than entry-level tablets.

ABI senior mobile devices analyst Joshua Flood is quoted “Regardless of the tremendous historical eReader success, the market tides have already begun to turn. Nevertheless, the eReader market will not be totally cannibalized by media tablets. We believe there will always be a niche market for the dedicated reading device for voracious readers, business travelers, and educational segments, particularly ones that are low-priced.”

ABI senior practice director Jeff Orr continues “The decline of buying audiences for dedicated digital readers in the US is more rapid than the digital publishing ecosystems organizing for growth in Asia or Eastern Europe. Development of content digitalization systems and services in all world regions should continue without delay as the effort will be necessary for developing mobile app catalogs that provide easy search, discovery, and monetization.”

Be sure to check out the full ABI Research report.

Curiosity on Mars Bringing Back Memories

The Mars landing of Curiosity has brought back some memories when it comes to sensors and systems in space.....

It was 1980. I was a year out of college with an undergrad degree in microbiology and working in a hospital lab trying to figure out what I wanted to do for the rest of my life. At one time I had thought I wanted to go to medical school but the more time I spent in a hospital working in a clinical setting the more I realized I was not cut out for that kind of work. I loved the biology but I was struggling with the procedures - the work was 100% protocol - the same procedures over and over again with zero room for mistakes. So many of the people I worked with were so good at it - they thrived on it.  Me - I had always loved tinkering, taking things apart and trying to put them back together. Trying new things that did not always work was what I liked. Trying this instead of that. What if I did this? What would happen?

But.... when you are dealing with people's lives you can't do that kind of stuff. I have so much respect and envy for people who do this kind of work but I knew it ultimately was not for me. I loved the science but knew I had to change directions with respect to my career. Fortunately, something came along (as it often does in life) that helped me with my dilema.

In the lab one day we started testing a machine called the VITEK for McDonnell Douglas and NASA. VITEK was a fully automated microbial identification and susceptibility system that had been developed in the 1960's for use in space. The system is based on microbial growth in thin plastic identification cards that have small wells with sugars, enzymes, etc. After the cards have been inoculated with sample they are incubated at 37 degrees C and photometrically scanned every hour for either color change or turbidity. Different bacteria ferment different sugars, produce different byproducts, grow or don't grow based on nutrients or conditions, etc. Basically how they grow or do not grow is how they are identified.

McDonnell Douglas was looking to move the product from outer space into the hospital lab and we had engineers coming in and out of the lab weekly tweaking the system. We were running tests in parallel - we'd run a sample using traditional microbiological ID methods and run the same sample through the VITEK, comparing identification results. There was about a three week period when the engineers were in lots - the system was not working properly - something was screwed up in the incubation cycle and they were having a hard time figuring it out.

One of the engineers I had got to know came in with a large stack of green-bar  paper with thousands of lines of code one day. I had never seen actual code before - it was so logical and simple and organized. Really cool! I was able to look at it and quickly pick out where the error was - the incubation line was not properly placed in the incubation cycle loop. I showed the engineer what code lines needed to be swapped around and remember him scratching his head and shrugging his shoulders. Still, he made the mod and....... it worked! It was so trivial but it worked!! The engineers were looking too deeply into the code - this was sort of like a TV not working because it was not plugged in type of thing. That simple. I remember the guy telling me I should have been an engineer. I also remember him telling me the first time someone writes a program it never works and you always had to go back and troubleshoot it. I was intrigued - engineering - could it be for a tinkerer like me who likes to learn from my mistakes?

Well - long story short - my sister and two brothers had degrees in electrical engineering. They had been bugging me for a while to check out engineering. They talked me into going to see Dr Jim Masi (the same Jim Masi who was our first Director at www.ictcenter.org) at Western New England University and we were able to work out an agreement where I could pick up the undergrad courses I was missing and then move into an MS Electrical Engineering program. It took a while and most of the time was incredibly hard but I was able to complete the degree.

As an engineer I could now tinker and try new (sometimes off the wall) things and make mistakes and learn from those mistakes. And that microbiology background has never gone to waste - I know it has helped me think and approach problems a little differently than traditionally trained engineers. All good!