1. Digital Video and Audio Broadcasting Technology
2. ITU 2010 Supplement on Global ICT fora/consortia Survey
3. Cisco 2015 https://www.youtube.com/watch?v=H30RehH-CzQ
4. FCC 2011 Wireless E911 Location Accuracy Requirements; E911 Requirements for IP-Enabled Service Providers http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.394.2125&rep=rep1&type=pdf