Method for transferring data in a wireless network

Abstract

A process transfers data packets through a protocol stack employed by a device that transmits packets on a packet connection to a wireless network between at least two, distinct wireless access technologies such as GSM/GPRS and UMTS. A first layer of the stack stores a copy of a transferred packet until confirmation is received from a next, lower layer of successful transfer of the packet of the stack. In the absence of such confirmation and on the occurrence of a switch of the packet connection to a new connection path, particularly one of a different wireless access technology, the stored packet is transferred to the protocol stack to be employed by the wireless device for the new packet connection path. Consequently, the packet transfer process avoids packets being lost on the occurrence of a switch between different technology wireless access packet connection paths.

1 . A method of transferring data packets in a wireless device capable of being operated in accordance with two wireless access technologies of a wireless network, comprising:
 transferring a data packet from a first layer of a protocol stack employed by the device for a packet connection with the network to a second, lower layer of said stack;   receiving at said first layer an indication from said lower layer of receipt of said data packet in the event of successful transfer of the data packet by the first layer to the second layer;   receiving an indication that the packet connection is to be switched to a new packet connection path; and   in response transferring any unsuccessfully transmitted data packets to a transmit queue of the new connection path.   
     
     
         2 . The method of  claim 1 , wherein the first layer transfers an identifier associated with said data packet to the second, lower layer and wherein said lower layer returns the identifier to the first layer as the indication that the data packet has been received by the lower layer thereby confirming successful transfer of the data packet by the first layer to the second layer. 
     
     
         3 . The method of  claim 1 , wherein the transferring is repeated between each layer and a next, lower layer of the protocol stack employed by the wireless device for the packet connection to the network. 
     
     
         4 . The method of  claim 3 , wherein it includes each lower layer of the protocol stack returning an identifier associated with the data packet to the next, higher layer in the stack whereby receipt of the identifier by the first layer confirms successful transfer of the data packet through all the layers of the protocol stack employed by the wireless device. 
     
     
         5 . The method of  claim 1 , wherein the first layer stores a copy of the data packet and maintains said copied packet until it receives any of an indication from the second layer of receipt of the data packet, an indication that the packet connection associated with the packet transfer process is to be terminated or the indication that the packet connection is to be switched to a new packet connection path. 
     
     
         6 . The method of  claim 5 , wherein, upon receipt of the indication from the second layer of receipt of the data packet or the indication that the packet connection is to be terminated, the first layer discards the stored copy of the data packet. 
     
     
         7 . The method of  claim 5 , wherein, upon receipt of the indication that the packet connection is to be switched to a new packet connection path and in the absence of the indication from the second layer of receipt of the data packet, the first layer transfers the stored copy of the data packet to a first layer of a protocol stack to be employed by the wireless device for the new packet connection path. 
     
     
         8 . The method of  claim 1 , wherein it includes a lower layer of the protocol stack employed by the wireless device for the packet connection with the network segmenting the data packet received from a next, higher layer of the stack to provide smaller packets for transferring to a next, lower layer of the stack and maintaining a correspondence between the smaller packets and the data packet from which they were segmented. 
     
     
         9 . The method of  claim 9 , wherein the lower layer of the stack associates an identifier with each of the smaller packets, wherein subsequent receipt by said layer from the next, lower layer of all of the smaller packets identifiers confirms successful transfer of all of said smaller packets to the next, lower layer and triggers said lower layer to return to the next, higher layer an identifier associated with the original data packet. 
     
     
         10 . The method of  claim 7 , wherein the protocol stack of the packet connection path operates in accordance with a first access technology of the wireless network and the protocol stack of the new packet connection path operates in accordance with a second access technology of the wireless network. 
     
     
         11 . The method of  claim 10 , wherein the first access technology of the wireless network is one of GPRS or UMTS and the second access technology is the other of GPRS or UMTS. 
     
     
         12 . A wireless device for transferring data packets over a packet connection with a wireless network, said device being operable in accordance with two wireless access technologies of the wireless network, comprising:
 a processor for transferring a data packet from a first layer of a protocol stack employed by the device for a packet connection with the network to a second, lower layer of said stack; said processor being arranged to receive at said first layer an indication from said lower layer of receipt of said data packet in the event of successful transfer of the data packet by the first layer to the second layer; to receive an indication that the packet connection is to be switched to a new packet connection path; and   in response to transfer any unsuccessfully transmitted data packets to a transmit queue of the new connection path.   
     
     
         13 . The device of  claim 12 , wherein the processor is arranged to associate an identifier with said data packet at said first layer and to transfer said identifier to said second, lower layer and arranged to receive the identifier from the second layer to thereby confirm successful transfer of the data packet by the first layer to the second layer. 
     
     
         14 . The device of  claim 12 , wherein the processor is arranged to repeat the transferring and receiving between each layer and a next, lower layer of the protocol stack employed by the wireless device for the packet connection to the network. 
     
     
         15 . The device of  claim 14 , wherein the processor is arranged to return from each layer of the protocol stack an identifier associated with the data packet to the next, higher layer in the stack whereby receipt of the identifier by the first layer confirms successful transfer of the data packet through all the layers of the protocol stack employed by the wireless device. 
     
     
         16 . The device of  claim 12 , wherein the processor is arranged to store a copy of the data packet in a memory component of the device and to maintain in said memory said copied packet until it receives at said first layer of the stack any of an indication from the second layer of receipt of the data packet, an indication that the packet connection associated with the packet transfer process is to be terminated or an indication that the packet connection is to be switched to a new packet connection path. 
     
     
         17 . The device of  claim 16 , wherein, upon receipt by the processor of the indication from the second layer of receipt of the data packet or the indication that the packet connection is to be terminated, the processors discards the stored copy of the data packet from the memory component. 
     
     
         18 . The device of  claim 16 , wherein, upon receipt by the processor of the indication that the packet connection is to be switched to a new packet connection path and in the absence of receipt at said processor of the indication from the second layer of receipt of the data packet, the processor transfers the stored copy of the data packet from the memory to a buffer of a first layer of a protocol stack to be employed by the wireless device for the new packet connection path. 
     
     
         19 . The device of  claim 12 , wherein it includes means for segmenting the data packet at a lower layer of the protocol stack employed by the wireless device for the packet connection with the network and means for maintaining a correspondence between the smaller packets and the data packet. 
     
     
         20 . The device of  claim 19 , wherein the means for segmenting associates an identifier with each of the smaller packets, wherein subsequent receipt by said layer from the next, lower layer of all of the smaller packets identifiers confirms successful transfer of all of said smaller packets to the next, lower layer and triggers said processor to return to the next, higher layer an identifier associated with the original data packet. 
     
     
         21 . The device of  claim 18 , wherein the protocol stack of the packet connection path is operated in accordance with a first access technology of the wireless network and the protocol stack of the new packet connection path is operated in accordance with a second access technology of the wireless network. 
     
     
         22 . The device of  claim 21 , wherein the first access technology of the wireless network is one of GPRS or UMTS and the second access technology is the other of GPRS or UMTS. 
     
     
         23 . The device of  claim 12 , wherein the device comprises a mobile wireless communications device. 
     
     
         24 . A non-transitory computer readable storage medium containing code means for a wireless device for transferring data packets over a packet connection with a wireless network, said device being operable in accordance with two wireless access technologies of the wireless network, the code means being executable on a processor of the device to:
 transfer a data packet from a first layer of a protocol stack employed by the device for a packet connection with the network to a second, lower layer of said stack; and   receive at said first layer an indication from said lower layer of receipt of said data packet thereby in the event of successful transfer of the data packet by the first layer to the second layer; receive an indication that the packet connection is to be switched to a new packet connection path; and   in response to transfer of any unsuccessfully transmitted data packets to a transmit queue of the new connection path.   
     
     
         25 . A system comprising an electronic device for transferring packets on a packet connection through a wireless network, said wireless network including two wireless access networks of different technologies, wherein said device comprises:
 a processor for transferring a data packet from a first layer of a protocol stack employed by the device for a packet connection with the network to a second, lower layer of said stack; said processor being arranged to receive at said first layer an indication from said lower layer of receipt of said data packet in the event of successful transfer of the data packet by the first layer to the second layer; to receive an indication that the packet connection is to be switched to a new packet connection path; and   in response to transfer any unsuccessfully transmitted data packets to a transmit queue of the new connection path.