Mobile data communication

Abstract

A method provides data communication to a vehicle. The method comprises a first data packet from a device associated with said vehicle at an intermediate device, said first data packet comprising a first identifier identifying said vehicle, modifying said first identifier to identify said intermediate device and forwarding said modified first data packet from said intermediate device to a further device. A communications session between said device associated with said further device is established, and a session identifier is associated with the communications session, and said first data packet comprises said session identifier and said modified data packet comprises said session identifier.

I claim: 
     
         1 . A method of providing data communication to a vehicle, the method comprising:
 establishing a connection with a first base station at a first time, and transmitting data packets from the vehicle to the first base station;   establishing a connection with a second base station at a second later time, and transmitting data packets from the vehicle to the second base station after said second time;   receiving data packets from said first base station after said first time and after said second time.   
     
     
         2 . The method of  claim 1 , wherein said connection with said first base station is a wireless connection and said connection with said second base station is a wireless connection. 
     
     
         3 . The method of  claim 1 , comprising receiving data packets from said second base station after said second time. 
     
     
         4 . The method of  claim 3 , further comprising:
 severing said connection with said first base station at a third time, said third time being later than said second time, such that data packets are received from said first base station and said second base station during a time between said second time and said third time and such that data packets are not received from said first base station after said third time.   
     
     
         5 . The method of  claim 1 , wherein said first base station and said second base station each communicate with a further device, and a communications session is established between said vehicle and said further device. 
     
     
         6 . The method of  claim 5 , wherein data packets transmitted from the vehicle to each of said first and second base stations are part of said communications session and data packets received at the vehicle from each of said first and second base stations are part of said communications session 
     
     
         7 . The method of  claim 1 , wherein each of said first and second base stations communicates with said further device via a home agent. 
     
     
         8 . The method of  claim 7 , wherein said home agent receives, at a fourth time after said first time, from said first base station, a first data packet transmitted from said vehicle to said first base station, and stores data associating said first base station with said vehicle in response to said first data packet. 
     
     
         9 . The method of  claim 8 , wherein said first data packet is provided to said further device by said home agent. 
     
     
         10 . The method of  claim 9 , wherein said further device generates a first response to said first data packet and provides said response to said home agent. 
     
     
         11 . The method of  claim 10 , wherein said home agent transmits said first response to said vehicle via said first base station based upon said data associating said vehicle with said first base station. 
     
     
         12 . The method of  claim 11 , wherein said first response is transmitted to said first base station at a fifth time, said fifth time being after said fourth time and before said third time. 
     
     
         13 . The method of  claim 7 , wherein said home agent receives from said second base station, a second data packet transmitted from said vehicle to said second base station, and stores data associating said second base station with said vehicle in response to said second data packet. 
     
     
         14 . The method of  claim 13 , wherein said second data packet is received at a sixth time, said sixth time being after said fifth time. 
     
     
         15 . The method of  claim 13 , wherein said second data packet is provided to said further device by said home agent. 
     
     
         16 . The method of  claim 13 , wherein said further device generates a second response to said second data packet and provides said response to said home agent. 
     
     
         17 . The method of  claim 16 , wherein said home agent transmits said second response to said vehicle via said second base station based upon said data associating said vehicle with said second base station. 
     
     
         18 . The method of  claim 17 , wherein said second response is transmitted to said first base station at a seventh time, said seventh time being after said sixth time. 
     
     
         19 . The method of  claim 1 , wherein each of said first and second base stations is configured to:
 receive a data packet from said vehicle, said data packet comprising a source identifier identifying said vehicle; and   modify the received data packet to replace said source address identifying said vehicle with a source identifier identifying said base station, wherein said source identifier identifying said vehicle.   
     
     
         20 . The method of  claim 19 , wherein said source identifier is an identifier of a network device located on board the vehicle. 
     
     
         21 . The method of  claim 20 , wherein the network device located on board the vehicle is arranged for communication with a plurality of wireless devices located on board the vehicle. 
     
     
         22 . An apparatus for providing data communication to a vehicle, the apparatus comprising:
 an interface for establishing a connection with a first base station at a first time and transmitting data packets from the vehicle to the first base station and for establishing a connection with a second base station at a second later time and transmitting data packets from the vehicle to the second base station after said second time;   wherein the interface is arranged to receive data packets directly from said first base station after said first time and after said second time.   
     
     
         23 . A non-transitory computer readable medium carrying a computer program comprising computer readable instructions adapted to cause a computer to carry out the method of  claim 1 .