1. GSMA Intelligence 2016 Global data https://gsmaintelli gence.com/
2. United States Census Bureau 2016 U.S. and World Population Clock http://www.census.gov/popclock/
3. Beecham Internet of things: worldwide M2M market forecast 2008
4. Machina M2M communications in automotive 2010-2020,” “M2M communications in healthcare 2010-2020,” “M2M communications in consumer electronics 2010-2020,” “M2M communications in utilities 2010-2020,” “M2M global forecast and analysis 2010-2020 2008