# US 2013/0156006 A1 · Method for providing seamless transition between networks following different protocols > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0156006 A1 - Document ID: US20130156006A1 - Status: Published application - Kind: A1 - Application number: 13/768,460 - Filed: 2013-02-15 - Published: 2013-06-20 - Earliest claimed: 2008-06-05 - Assignees: Alcatel Lucent - Inventors: Peter BOSCH; Frank R. FAVICHIA - Web page: https://patentgrep.com/patent/US20130156006A1 ## CPC - H04W 92/02: Inter-networking arrangements - H04L 69/04: Protocols for data compression, e.g. ROHC - H04L 69/18: Multiprotocol handlers, e.g. single devices capable of handling multiple protocols - H04W 36/1443: {between licensed networks} - H04L 69/085: specially adapted for interworking of IP-based networks with other networks - H04W 28/06: Optimizing {the usage of the radio link}, e.g. header compression, information sizing {, discarding information (system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365)} - H04W 36/02: Buffering or recovering information during reselection {; Modification of the traffic flow during hand-off} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Example embodiments provide methods for handling the transition of a mobile device from a first network to a second network, the second network operating according to a different communications protocol from the first network. One example embodiment includes terminating forwarding of the data packets from the first network to the mobile device; rebuilding headers of unforwarded data packets at the first network; and sending the rebuilt data packets from the first network to the second network. Another example embodiment includes resetting a header compression state at the second network; receiving unforwarded data packets from the first network at the second network, the unforwarded data packets being data packets the first network had not yet forwarded to the mobile device; and sending the unforwarded data packets from the second network to the mobile device. ## Claims ### Claim 1 A method of handling a transition of a mobile device from a first network to a second network, the method comprising: terminating forwarding of data packets from a first server in the first network to the mobile device; rebuilding headers of unforwarded data packets at the first server using a decompression dictionary stored at the first server to decompress compressed headers of the unforwarded data packets, the decompression dictionary built by the first server using data packets previously forwarded to the mobile device; and sending the rebuilt data packets from the first server to the second network, the second network operating according to a different communication protocol from the first network. ### Claim 2 (depends on 1) The method of claim 1, wherein the first network is a network following a CDMA2000 protocol and the second network is a network following an LTE protocol. ### Claim 3 (depends on 1) The method of claim 1, wherein the first server is a controller and the method further comprises: storing the unforwarded data packets in a buffer at the controller in the first network. ### Claim 4 (depends on 1) The method of claim 1, wherein the rebuilding headers includes using information stored at the first network to decompress compressed headers of the unforwarded data packets. ### Claim 5 (depends on 1) The method of claim 1, wherein the rebuilding headers includes using information stored at the first server to decompress compressed headers of the unforwarded data packets. ### Claim 6 (depends on 3) The method of claim 3, wherein the first server is a controller and the sending the rebuilt data packets to the second network includes sending the rebuilt data packets from the controller to the second network. ### Claim 7 (depends on 2) The method of claim 2, wherein the first server is a Radio Network Controller (RNC) and the sending the rebuilt data packets to the second network includes sending the rebuilt data packets from the RNC to the second network. ### Claim 8 (depends on 7) The method of claim 7, further comprising: building the decompression dictionary by the RNC using the data packets previously forwarded to the mobile device. ### Claim 9 (depends on 7) The method of claim 7, wherein the sending of the rebuilt data packets is via a channel between the RNC and an Access Gateway in the second network. ### Claim 10 A method of handling a transition of a mobile device from a first network to a second network, the method comprising: resetting a header compression state at the second network to clear any compression dictionary previously established at the second network for the mobile device and resynchronize the compression dictionary at the second network with a decompression dictionary at the mobile device, if the mobile device transitions to the second network; receiving unforwarded data packets from the first network at the second network, the second network operating according to a different communications protocol from the first network, the unforwarded data packets being data packets the first network had not yet forwarded to the mobile device; and sending the unforwarded data packets from the second network to the mobile device. ### Claim 11 (depends on 10) The method of claim 10, wherein the first network is a network following a LTE protocol and the second network is a network following a CDMA2000 protocol. ### Claim 12 (depends on 10) The method of claim 10, wherein the receiving unforwarded data packets at the second network includes receiving data packets at a controller in the second network. ### Claim 13 (depends on 12) The method of claim 12, wherein the resetting of the header compression state at the second network is performed by sending a PPP (point-to-point protocol) message. ### Claim 14 (depends on 13) The method of claim 13, wherein the resetting is performed by sending the PPP message from the controller. ### Claim 15 (depends on 11) The method of claim 11, wherein receiving unforwarded data packets at the second network includes receiving unforwarded data packets at a Radio Network Controller (RNC) in the second network. ### Claim 16 (depends on 15) The method of claim 15, wherein the receiving of the unforwarded data packets at the RNC is via a channel between the RNC and an Access Gateway in the first network. ### Claim 17 (depends on 10) The method of claim 10, wherein the unforwarded data packets received at the second network have uncompressed headers and the resetting is performed when the second network receives the unforwarded data packets.