An Explanation of SMS and Its Limitations

SMS Texting: What is it and what are its limits?

Message Bubbles Smart Phone
Message Bubbles Smart Phone. bijendra/Getty Images

SMS stands for short message service and is used pervasively around the globe. In 2010, over 6 trillion SMS texts were sent, which was equivalent to around 193,000 SMS messages every second. (This number was tripled from 2007, which saw just 1.8 trillion.) By 2017, millennials alone were sending and receiving nearly 4,000 texts every month. 

The service allows for short text messages to be sent from one cell phone to another or from the internet to a cell phone.

Some mobile carriers even support sending SMS messages to landline phones, but that uses another service between the two so that the text can be converted to voice in order to be spoken over the phone.

SMS began with support just for GSM phones before later supporting other mobile technologies like CDMA and Digital AMPS.

Text messaging is very cheap in most parts of the world. In fact, in 2015, the cost of sending an SMS in Australia was calculated to be just $0.00016. While the bulk of a cell phone bill typically is its voice minutes or data usage, text messages are either included in the voice plan or are added as an extra cost.

However, while SMS is pretty cheap in the grand scheme of things, it does have its drawbacks, which is why text messaging apps are becoming more popular.

Note: SMS is often referred to as texting, sending text messages or text messaging. It's pronounced as ess-em-ess.

What Are the Limits of SMS?

For starters, SMS messages require a cell phone service, which can be really annoying when you don't have it. Even if you have a full Wi-Fi connection at home, school, or work, but no cell service, you can't send a regular text message.

SMS is usually lower on the priority list than other traffic like voice.

It's been shown that around 1-5 percent of all SMS messages are actually lost even when nothing is seemingly wrong. This questions the reliability of the service as a whole.

Also, to add to this uncertainty, some implementations of SMS don't report whether the text was read or even when it was delivered.

There's also a limitation of characters (between 70 and 160) that depends on the language of the SMS. This is due to a 1,120-bit limitation in the SMS standard. Languages like English, French, and Spanish use GSM encoding (7 bits /character) and therefore reach a max character limit at 160. Others that use UTF encodings like Chinese or Japanese are limited to 70 characters (it uses 16 bits /character)

If an SMS text has more than the maximum allowed characters (including spaces), it's split into multiple messages when it reaches the recipient. GSM encoded messages are split onto 153 character chunks (the remaining seven characters are used for segmentation and concatenate info). Long UTF messages are broken into 67 characters (with just three characters used for segmenting).

MMS, which is often used to send pictures, extends upon SMS and allows for longer content lengths.

SMS Alternatives and the Demise of SMS

To combat these limitations and provide users with more features, many text messaging apps have surfaced over the years.

Instead of paying for an SMS and facing all of its disadvantages, you can download a free app on your phone to send text, videos, images, files and make audio or video calls, even if you have zero services and are just using Wi-Fi.

Some examples include WhatsApp, Facebook Messenger, and Snapchat. All of these apps not only support read and delivered receipts but also internet calling, messages that aren't broken into pieces, images and videos.

These apps are all the more popular now that Wi-Fi is available in basically any building. You don't have to worry about having cell phone service at home because you can still text most people with these SMS alternatives, so long as they're using the app as well.

Some phones have built-in SMS alternatives like Apple's iMessage service that sends texts over the internet. It works even on iPads and iPod touches that don't have a mobile messaging plan at all.

Note: Remember that apps like the ones mentioned above send messages over the internet, and using mobile data is not free unless, of course, you have an unlimited plan.

More Uses for SMS

It might seem like SMS is only useful for simple texting back and forth with a friend, but there are a couple other major areas where SMS is seen.

Marketing

Mobile marketing uses SMS too, like to promote new products, deals, or specials from a company. Its success can be contributed to how easy it is to receive and read text messages, which is why the mobile marketing industry was said to be worth around $100 billion as of 2014.

Money Management

Sometimes, you can even use SMS messages to send money to people. It's similar to using email with PayPal but instead, identifies the user by their phone number. One example is Square Cash.

Security

SMS is also used by some services for receiving two-factor authentication codes. These are codes that are sent to the user's phone upon requesting to log in to their user account (like on their bank website), to verify that the user is who they say they are.

An SMS contains a random code that the user has to enter into the login page with their password before they can sign on.