1. Integrated GPS receiver offers ultra-low power consumption. http://rfdesign.com/news/integrated-GPS-receiver .
2. POLS: Privacy-Observant Location System. http://pols.sourceforge.net .
3. Seamless and Secure Mobility Tool Suite, Mobility Package for ns-2. http://www.antd.nist.gov/seamlessandsecure.shtml .
4. SMS FAQ. http://www.gsm-technology.com/gsm.php/en,unlock,subpage_id,smsfaq.html .
5. The Network Simulator-ns-2. http://www.isi.edu/nsnam/ns .