One thing I get hassled about all the time for by friends and family is not having text messaging (or SMS) on my cell phone. That’s right. I am probably one of the few cell phone subscribers in America that do not have a plan that includes text messaging or even the ability to text on my cell phone.

When I got the phone plan that I am currently on, I requested that the ability to receive or send text messages be removed from my phone. At the time I figured, I have a phone; why would pay extra money so I can type and read on a phone when I can simply talk to someone? A few times since then, I have thought about purchasing a text messaging plan after a hand full of situations occurred when text messaging would have be useful. However, when I realized the price I would be paying for text messaging, I quickly let the thought fade away. The cost outweighed the value returned to me, so, I opted to remain without.

To understand why I could not, and still cannot, justify the cost, we would have to look at both the cost and the technology surrounding text messaging. Note: I apologize for the tech talk and math in advance.

  • Text Messages: Each text message is limited to 160 characters (ASCII characters). Each character is comprised on 7-bits (combinations of 1’s and 0’s). This means the maximum size of a text message is 1120 bits (160*7). The average industry cost to receive (or send) one text message if you do not have a text messaging plan is $.20. That means, each bit cost approximately $0.000179 per bit or $0.00143 per byte (8 bits=1 byte).
  • Voice Calls: Since most companies round to the nearest minute, I will say the minimum limit on a phone call is 60 seconds. To talk on the phone for one minute your phone will transfer approximately 3,840,000 bits per minute, and here is how I got that. The maximum audio frequency (fmax) transmitted by cell phones is approximately 4khz (4000 cycles per second). Based on Nyquist-Shannon Sampling Theorem a phone must sample at a minimum rate of 2*fmax. Hence, the minimum sampling rate is 8,000 samples per second. Each of the samples contains 8 bits and thus 64,000 bits per second. Multiply 64,000 by 60 seconds and we receive the approximate number of bits mentioned above. To purchase an additional minute outside of a calling plan, most cell phone carriers charge $.50 per minute. This means each bit cost approximately $1.30*10-7 per bit ($1.04*10-6 per byte).

What does this all mean? Well for a cell phone subscriber to send 1,000,000 bits of data via text it will cost approximately $179. To send the same amount of data via a phone call it cost approximately $0.13. If you are trying to make yourself feel better by saying, “That is why I bought a text plan”, please do note that I am comparing extra text messaging to extra minutes. The numbers are just about the same for a texting plan vs. a calling plan.

Is there a way to justify the cost? Well, there really isn’t. Text messages are sent on a cell phone’s “control channel”. This is the channel that helps the phone company locate you, identify your cell phone, set-up calls, and transfer your cell calls between cell phone towers. Almost all these functions are occurring as long as your cell phone is on (powered up). Hence, you are already paying for this. Furthermore, each cell tower can only handle a limited amount of actual voice calls. By users opting to send and receive text vs. making a phone call they are HELPING cell phone providers provide service to additional customers and HELPING the phone company maintain other subscriber’s phone calls. In other words, the chances of a subscriber getting on the cell phone network to make a voice call are increased thanks to texting, and the ability for the network to transfer voice calls from tower to tower is also increased thanks to texting. As a texter, what are you getting for your help? Well, the phone companies are asking you to pretty much pay twice for something (the control channel usage) you already pay for and to make their system more efficient.

One defense I hear for text messaging is that you can send quick messages without having to start a possibly long conversation. To me, a cheaper solution would be to place a voice call and start with, “One quick question” or “Just have to let you know really quick”. By doing this, you immediately let the person you are calling know your intent. If it is impossible to have a short conversation with someone, then do what I do. Don’t call that person until you have the time to talk or don’t answer the phone when you are busy (Opps! My secret is out).

In short, the few times text messaging would have been a necessity in my life does not justify the cost. When the math does work out, I will add text messaging to my cell phone plan. Until then, friends and family, you will just have to call me. If I do not answer, leave a message.