Will text messaging work in disaster?

People texting on cell phonesAfter 2001, many people have been pushing the benefits of text messaging over voice phone call to get message through. Experience shows that text messaging is more reliable to get message through but it is not the perfect alternative means to contact someone that it is implied to be. Nine years ago, relatively few people used their cell phones to send text messages. Times have changed.

CTIA reports that total subscribers have grown from 128 million in 2001 to 270 million in 2008 – little more than double. The usage has sky rocketed with 450 billion minutes used in 2001 to over 2 trillion minutes used in 2008 – almost five times. Lastly, in the few years from 2005 to 2008, text messages have exploded to 110 billion messages sent – over ten times growth in half the time as the other figures.

There are 304 million people in the United States. An interesting comment made during the CTIA convention keynote is that the wireless industry doesn’t need to stop at 100% penetration. The wireless industry is looking for 200 to 300% percent penetration. How is this possible? People carry multiple devices. I carry personal cell phone and work cell phone; that is 200% penetration there. All these numbers have profound impact on the network that carries all the voice and data traffic. The networks are designed to maximize efficiencies and minimize cost. Compare it to your local gym. It can handle the day-to-day traffic easily except on Jan when everyone starts their New Year’s resolutions.

NCS outlined very plausible scenario in one of their technical bulletins.

“As of April 2000, Washington, DC, had population of 572,059 distributed over 68 square miles. This equates to an average density of 8,388 people/sq mi. Assuming Washington is covered by 40 cell sites with 120 sectors, each sector would cover an average of ½ to ¾ square mile (there is overlap in the coverage areas). Based on coverage area and population density, an average sector covers approximately 6000 people. Washington DC has around 60% penetration, or 3600 subscribers per sector. They could generate 3600 messages/minute in each sector, or 30 times greater than the 120 SMSs/min sector can process.”

While this report is dated and many changes have taken place, think back to the earlier figures where there was ten-fold growth in text messages from 2005 to 2008. The report also notes that the DC population goes up during the day with all the commuters coming in from the suburbs to work. Therefore, everyone trying to text message nearly at the same time will clog up the system.

Recent news has proven that text messaging is neither instant nor real-time. The Washington Post reports that when Barack Obama announced his running mate in the 2008 election people still did not receive the text message 12 hours after it was sent. Purdue did text messaging test with nearly 10,000 students in September 2007. Their results showed that it took seven minutes to send all the messages out with about 30 students never receiving the message.

So where does this all lead us? People need to have multiple methods of communication in disaster. I’ll always try my normal method first. If need to reach family, I’ll dial the 10-digits for voice. When that doesn’t work then I’ll use combination of email, SMS text messages, Blackberry PIN messages – even changing my outgoing voicemail message to say I’m ok – to get my message across to family and other people who are important.

Next time you hear someone say that they’re going to text message during major event in their area, ask what they plan to do if that doesn’t go through. I’d bet they are assuming it does.


AT&T, Test Messaging and Emergency Notification Systems. (White paper published on AT& Enterprise website, www.att.com/business). This contains lot of good and technical information plus disclaimers that AT&T doesn’t recommend SMS text messaging as the only solution for critical first-responder notifications.

CTIA, 2009 Semi-Annual Wireless Industry Survey. (http://files.ctia.org/pdf/CTIA_Survey_Year-End_2008_Graphics.pdf).

CTIA, Wireless Quick Facts. (http://www.ctia.org/media/industry_info/index.cfm/AID/10323).

NCS, Technical Bulletin #03-, SMS over SS7. (http://www.ncs.gov/library/tech_bulletins/2003/tib_03-.pdf)

Washington Post, Jose Antonio Vargas, Obama’s Text: Message Received, With Few Garbles. Aug 2008. http://voices.washingtonpost.com/44/2008/08/23/obamas_text_message_received_.html)