Istanbul, Buenos Aires, Hong Kong; all taxis chose the PTT system

• Secure wide area communication. Aid delivered in case of emergency
• No radio license, antenna site, infrastructure fees
• Cost-effective; no need to buy expensive equipment but standard handsets
• Coverage almost everywhere 
• Different groups for different sectors
• Push-To-Talk can be connected to existing radio systems
• Easy to use
• Low cost compared to complex dispatching installations