Skip to main content

Instant Messaging (IM) vs. Short Message System (SMS) Messaging

By Saturday, March 25, 2006No Comments

Chatter Mediums – Instant Messenger vs Short Messaging Service (or IMvSMS)
Mohit SantRam – Friday, March 24th, 2006
Every Bit You Make – Raffi Krikorian
ITP – New York University

As of 2006, there are many well established interpersonal communication mediums that people use to augment typical face to face communication. From handwritten notes, to email, to instant messenger protocols, to short messages transmitted from mobile phone to mobile phone; people have numerous communication choices. As with any form of communication – the real question to consider is what is the medium based on the situation? It’s not so much the message content – or how the message is technically sent – but what matters is how the person on the receiving end of the message is viewing the message. While there are many ways in which I communicate with my friends and family, I am specifically interested in the similarities and differences with Instant Messaging and SMS protocols.

Instant Messaging (IM)
There are many different platforms that one can use within the umbrella of Instant Messaging. Though the most popular application is America On-Line’s Instant Messenger – one can use iChat, ICQ, MSN Messenger, Yahoo! Messenger on most operating systems to connect with their friends. Although the application clients on Apple MacOS, Linux, Microsoft Windows, or UNIX (et al.) may differ in appearance, there functionality is more or less that same. There is no restriction for users to send and receive messages except the user’s connection. Since the communication protocol is not Operating System specific, the sender and receiver are not limited to using the same OS or the same application, only to the communication specification.

AOL’s Instant Messenger protocol is by far the most ubiquitous Instant Messaging protocol. As a Macintosh user, I use AOL Instant Messenger to communicate online with the majority of my family and friends. Although I have choice between using AOL’s Instant Messenger, Apple’s iChat, or Adium; a multi-protocol enabled messaging client that allows users to use one application to communicate; for intensive purposes I am only limited by what protocol my friends and family use. While each protocol on each client on each platform may offer unique settings, the majority of the communication medium is the same – users may send and receive messages through their computer.

Each IM protocol is limited to sending and receiving messages within their specification. For example, a MSN Messenger user cannot send an IM message to an AOL Instant Messenger nor to a Yahoo! Messenger user or vice versa. AOL’s IM service employs synchronous messaging, while Yahoo! Messenger allows users to send messages asynchronously. Although the obvious benefit to Yahoo!’s approach is that the recipient does not need to be online to be sent a message – this unique convenience/feature has not translated to a larger user base.

Every Instant Messaging platform requires users to create a unique username to identify themselves during the sign up process. Users may now only send messages and receive messages to others within the same IM protocol, so long as they know someone’s account username or email address. Determining someone’s username traditionally comes through direct communication, search within the instant messaging service, e-mail, through friends of friends, or via word-of-mouth. But for any messages to be sent and received requires that the sender knows the recipient’s username.

Each protocol allows users to add their contacts to a “Buddy List”. While the name of the list may be different on each platform – the fact of allowing a user to create a shortcut to their friends via a contact list is profound. Having such list allows people to focus on exchanging messages and not on remembering all of their usernames. A message is initiated from the sender’s IM client. A user can either select a name from their contact list or create a blank message and enter the recipient’s username. Depending on their client – a user can send a plain or formatted text message, files, links, images, and encrypt their messages.

Short Message Service Messaging (SMS)
The Short Message Service, available on most digital handsets, allows the sending and receiving of short text messages between mobile phones, computers, and other communications devices. While the advent of the SMS system is difficult to place on a specific date – the first SMS message to be sent from one person to another was in 1992. The original purpose of sending short messages to mobile handsets was never meant to be a personal communications medium. SMS messages, originally intended as part of the GSM specification, were designed to relay information, such as voice mail alerts, from Mobile Phone Companies and Service Providers to handsets.

Most SMS messages can be sent to and from any cell phone with phone service. In the last several years, major phone providers within the U.S. have slowly been easing the lines between their services to allow users to send messages to and from different carriers and different devices. Up until the last two-to-three years, many people in the U.S. could not send SMS or Multimedia Messaging Service (MMS) messages between services. Until people could send SMS and MMS messages to recipients on other mobile service providers, mobile messaging did not take off. It is estimated that approximately 600 billion text messages are being sent every year. As more people use SMS messaging to quickly relay notes – the number is sure to rise.

Since most mobile handsets use a digital network for access – most mobile phones are capable of sending and receiving SMS messages. Though some mobile providers charge their customers an additional monthly fee for SMS and MMS capability, it’s popularity is rising quickly. To create a SMS message – users need only know the recipient’s mobile number. Users can also simply create an SMS message computer and to send to the recipient’s mobile phone or computer. Unlike Instant Messaging clients – users maintain their contacts within their phone’s address book.

SMS Messages are written using the keypad on one’s mobile handset. While it is not as easy to write a text message on one’s mobile phone – technologies such as T9, which incorporates word recognition and pattern matching to commonly typed words; exist to reduce typing time. Using T9 to type the message “Hello World” may only require pressing eleven buttons instead of typing through each number to get to the desired letter. As a result shorthand, which gained popularity with Instant Messaging, allows users to reduce typing time and still getting their message across.

Since the SMS or MMS message is sent from one phone to their service provider – each message is routed to the recipient as soon as possible. If the recipient’s phone is off or they are out of service range – the message is held in a queue until it can be delivered. Like asynchronous Instant messaging, SMS messages allow the recipient to read and/or respond to them when they so choose. While there is no guarantee that SMS or MMS messages will always reach their recipient – users rely on the technology to disseminate information quickly. As we have seen in Spain and the Philippines, governments have been toppled through the use of SMS messages from flash mobs.

What two or three aspects of one are different than the other?
While Instant Messaging requires the use of a specified unique username, SMS messages piggyback on the already unique identity of the user’s mobile phone number. IM is largely synchronous in delivery of the messages. While the recipient can read and respond to the message at their leisure – so long as their machine is on, their internet connection is active, and their recipient is online. The length of most SMS messages is limited to about 160 characters per message, whereas the length of IM messages is much higher. Encryption is another difference. Users can encrypt their IM messages while SMS messages are sent through the service provider’s system, which does not guarantee encryption.
However the most significant difference between IM and SMS is the threading of messages. A typical IM conversation can incorporate many different threads as participants of a one-on-one message or chat group can send messages as quickly as they choose. A single IM conversation can be as complex as a face to face conversation with the participants shifting thoughts and asking and responding to different questions. Where as a SMS message is much like sending and receiving letters through a postal service. Each IM message can be sent faster and much more synchronously than SMS messages; the delivery of SMS messages is much slower. (though technically one could send SMS messages from a mobile phone or computer faster using prewritten messages.)

What facets are the same?
As discussed above, both Instant Messaging and Short Message Service messages can quickly relate information from one person to another. Both tools allow the broadcast of information from one person to many – in a shortened format. Both tools allow people to share information in a non-verbal method. Users do not have to be in same room, country or continent to use either service. Though the speed of delivery of the mediums is different – users of both has caused a shift in communication and the ability of being “available”.

Pick them apart, mash them back together again, and come up with something interesting to say.
The use of Instant Messaging and SMS messages has had a profound effect on interpersonal communication. My own usage patterns of both technologies have changed as I used the tools to communicate with my friends and family. In many ways, both mediums have replaced a noticeable amount of face-to-face and telephone communication. Many conversations, which may not have taken place, been a source of tremendous anxiety or difficulty, or could have been potentially embarrassing; now have an avenue that is easier to use. For reasons of convenience – these two communication mediums have gained popularity – but what should be considered is the rise in the aggregate amount of communication that has increased within the last twenty years. From the early days of mobile phone technology – to now where almost half of the youth in the United States has – or soon will have – their own personal mobile phone is astounding.

As we discussed in class – there are many vulnerabilities inherent to any communications medium. Both IM and SMS messages are not immune to being read or intercepted by parties other than the intended recipient. IM Messages can be intercepted using simple packet sniffing software. As we used Ethereal and KisMAC to sniff wi-fi networks and traffic – we were also able to sniff packets of data as they traveled all around us. While many IM clients have the ability to encrypt the data that is sent between users, these clients can also save the chat transcripts. These transcripts, like any file on one’s computer, is susceptible to theft like any file on one’s computer through physical or hacking. SMS messages are also insecure as a copy is kept on the sender’s and mobile phone. Unless each user does not delete or archive the SMS messages on their mobile phone, these messages are vulnerable via theft of one’s phone. Simply borrowing a friend’s phone for a moment and viewing their stored SMS messages is a breach of security. Weaknesses such as these would enable users like Eve and Mallory to intercept digital messages quickly and relatively easily.
As an aside, although I do use many disparate mediums to communicate with my friends, I would like to draw brief attention to the asynchronous communication patterns that persist on Flickr allows people to visually see what their friends and family have been doing while giving them the ability or not to leave asynchronous comments. While the majority of use on Flickr is to share moments through the use of imagery with others – it is extremely easy to “intercept the messages” simply by viewing ones photo-stream. There are a few choices for one to share their photos as they can share their photos with everyone, their contacts, or their friends.

The advent and popularity of mobile phones has enabled better communication amongst people throughout the globe. Both IM and SMS messages can be used in a variety of similar and different ways. The changes in ubiquitous computing patterns has not only effected the ability to communicate – but the need and desire to communicate.

Instant Messaging
“Abbreviated IM, a toype of communications service that enables you to create a kind of private chat room with another individual in order to communicate in real time over the Internet, analagous to a telephone conversation but using text-based, not voice-based, communication. Typically, the instant messaging system alerts you whenever somebody on your private list is online. You can then initiate a chat session with that particular individual.” *2

Short Message Service
“Short Message Service: available on digital GSM networks allowing text messages of up to 160 characters to be sent and received via the network operator’s message center to your mobile phone, or from the Internet, using a so-called “SMS gateway” website. If the phone is powered off or out of range, messages are stored in the network and are delivered at the next opportunity.” *4

“SMS: Short Messaging Service. A wireless messaging service that permits the transmission of a short text message from and/or to a digital mobile telephone (CDMA, including CDMA 1xRTT and other CDMA-based implementations; TDMA; GSM; or ESMR) terminal, regardless of whether the transmission originates and terminates on a mobile telephone, originates on a mobile telephone and terminates on a computer, or originates on a computer and terminates on a telephone.” *5



above – an IM chat window

AOL Buddy List

above – an AOL Buddy List

Initiate File Transfer

above – Initiating a File Transfer

Image Transfer

above – A File Transfer

IM Encryption

above – IM Encryption Settings


above – A Computer to SMS Message

Footnotes / Related Reading





Leave a Reply