AT&T and T-Mobile USA signed 10-year agreements with Transit Wireless on Monday.
Transit Wireless is a wireless company charged with building a wireless network in the subway system.
Under the agreement, at least six subway stations will have wireless service by late 2011. Wiring the rest of the system will take up to five more years. The service will not extend to moving trains.
Other carriers will be able to join the network.
Transit Wireless Chief Executive Chris Jaeger says the network is designed to carry many carriers.