Title of Invention

METHOD OF APPLYING FAST MOBILE INTERNET PROTOCOL VERSION 6 (MIPV6) FOR MOBILE NODES IN MOBILE NETWORKS

Abstract

The invention is related to Mobile IPv6. In particular, it deals with applying Fast MIPv6 to mobile network nodes during mobile router's handover. This invention explains a method of fast MIPV6 for mobile nodes in mobile networks with route optimizations based on ND-PROXY wherein the said method comprising the steps of: at the MR: constructing RA with the prefix information containing a new flag; triggering the sending of RA by MR as soon as PrRtAdv is received by MR; passing the new prefix, contained in the PrRtAdv message, to the MNISTs through RA; and immediately sending zero lifetime for the old prefix after handover; and at the MNN: initiating FMIPv6 messages without any actual handover occurring, when prefix information with the 'H' flag is received.

Full Text

FIELD OF INVENTION The invention in general relates to Mobile IPv6. Further, this invention relates to with applying Fast MIPv6 to mobile network nodes during mobile router's handover. More particularly the present invention relates to a method of fast MIPV6 for mobile nodes in mobile networks with route optimizations based on ND-proxy. DESCRIPTION OF RELATED ART The Route Optimization technique using ND-Proxy [RO] involves delegation of network prefix by MR to its MNN's. Each of the MNN's configures a COA from the delegated prefix and do route optimization [MIPv6]. But there is no prior method available to trigger Fast MIPv6 [FMIPV6] in Mobile Network Nodes to avoid loss of packets during Mobile Router's handover. Referring to Figure 1, MR starts getting beacons from R2. Assuming MR to be capable of performing Fast Handover: 1. MR sends an RtSolPr to R1 asking for the prefix information regarding R2. 2. R1 sends a PrRtAdv to MR. 3. MRsends FBU to Rl 4. R1 sends an FBAck to MR. 5. MR takes the new COA (4ffa::4) and then switches to R2. A bi-directional tunnel will be established between R1 and MR, and all packets destined to MR's previous COA (3ffa::4) will be tunneled by R1 to MR. Hence MR won't loose packets coming from CN during the handover. After the handover, MR will send zero lifetime for the earlier prefix (3ffa:: /64) and will delegate the new prefix (4ffa:: /64). MNN and VMN will delete their previous COA's and form new COA's based on the new prefix. Initially MNN is talking to CN and is moving with MR. 1. When MR undergoes handover from R1 to R2, MNN gets a zero lifetime for the old prefix ( 3ffa:: /64) and immediately gets a new prefix(4ffa:: /64). Since MNN undergoes no handover at the link-level, so Fast MIPv6 can't be triggered for MNN. Hence all packets destined to MNN's previous COA1(3ffa::3) are lost during the handover. Figure.2 shows the Prefix Information Option in a RA message. The 'O' flag has been added as a part of Route Optimization using ND-Proxy [RO]. It signifies that the corresponding prefix has been delegated by MR and MNNs should use this prefix for Route Optimization. SUMMARY OF THE INVENTION The primary object of this invention is, therefore, to invent a method for preventing loss of packets for the on-going sessions of MNNs when MR undergoes handover. Network Mobility [NEMO] is an emerging field. The Basic NEMO protocol doesn't talk about route optimization for mobile network nodes. Many solutions have been suggested for route optimization in NEMO and one of them is described in [RO]. With this route-optimization technique, the MNNs may loose packets for their on-going sessions when MR undergoes hand-over. This loss of packets is undesirable. The invention satisfies the following criteria: • Packet loss is avoided for the existing communication between MNN and CN while MR undergoes handover. • No reconfiguration or support of v6 routers (R1 and R2) required. • Interoperable with existing standards. • Simple and easily deployable. The purpose of the invention is to avoid packet loss for the existing communication between MNN and CN while MR undergoes handover. The invention deals with adding a new flag in the prefix information option of the RA message, and triggering FMIPv6 messages by the MNNs without any actual handover occurring, when they receive the prefix information with the new flag. MR sends the new flag in the prefix information when it receives PrRtAdv. Route Optimization based on ND-Proxy [RO] is assumed to be working. MR, MNN's and the Access Routers (R1 and R2) must be capable of FMIPv6. Accordingly, this invention explains a method of fast MIPV6 for mobile nodes in mobile networks with route optimizations based on ND-PROXY wherein the said method comprising the steps of: at the MR: (a) constructing RA with the prefix information containing a new flag; (b) triggering the sending of RA by MR as soon as PrRtAdv is received by MR; (c) passing the new prefix, contained in the PrRtAdv message, to the MNN's through RA; and (d) immediately sending zero lifetime for the old prefix after handover; at the MNN: (e) initiating FMIPv6 messages without any actual handover occurring, when prefix information with the 'H' flag is received. * When MNN's receive the 'H' flag, the said MNN indicates that the corresponding prefix is the one obtained by MR from PrRtAdv, and Fast MIPv6 is triggered where MNN's immediately form new prospective COA's and send FBU's. MR gets PrRtAdv from first Access Router R1 and sends RA to MNNs with 'H' flag set. MR sends FBU to first Access Router R1 as in normal FMIPv6 and MNN gets the new prefix, and sends FBU to first Access Router R1 through MR. In FMIPv6, first Access Router R1 and second Access Router R2 exchange HI and Hack messages for MR and MNN's prospective new COA's. First Access Router R1 sends the corresponding FBAcks to MR and MNN respectively and the said FBAcks are received by MR and MNN. MR undergoes handover and sends a zero lifetime for the old prefix to MNN. Then MR sends FNA to second Access Router R2 and MNN receives Zero lifetime for the old prefix and sends FNA to second Access Router R2 through MR. Then MR and MNN deliver packets using their respective new COA's and any packets destined to MR's or MNN's old COA's are tunneled by first Access Router R1 to their new COA's respectively. These and other objects, features and advantages of the present invention will become more readily apparent from the detailed description taken in conjunction with the drawings and the claims. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Figure 1 shows an IPv6 Network. Figure 2 shows a typical Prefix Option in an RA message. Figure 3 shows the proposed Prefix Option with the new 'H' flag. Figure 4 shows the operational diagram of the method disclosed in this invention. DETAILED DESCRIPTION OF THE INVENTION The preferred embodiments of the present invention will now be explained with reference to the accompanying drawings. It should be understood however that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. The following description and drawings are not to be construed as limiting the invention and numerous specific details are described to provide a thorough understanding of the present invention, as the basis for the claims and as a basis for teaching one skilled in the art how to make and/or use the invention. However in certain instances, well-known or conventional details are not described in order not to unnecessarily obscure the present invention in detail. Figure 1 shows an IPv6 Network. R1 and R2 are Access Routers attached to the IPv6 cloud. MR is a Mobile Router which has MNNs, VMNs and FNs as its network nodes. MR and MNNs are talking to a CN attached to the IPv6 Network. Prefixes (3ffa:: /64) and (4ffa:: /64) have been chosen for R1's and R2's network respectively. MR delegates R1's prefix [RO] to its network nodes The Figure depicts handover of MR (along with MNN) from R1 to R2. Figure 2 shows a typical Prefix Option in an RA message. V flag: Onlink Flag 'A' flag: Autonomous Address Configuration Flag 'R' flag: When set, indicates that the Prefix field contains a complete IP address assigned to the sending router. 'O' flag: This has been added as a part of Route Optimization [RO]. When set, it: indicates that the prefix can be used for route optimization of mobile nodes, which are either local mobile nodes or visiting mobile nodes within the mobile network. Valid Lifetime: The length of time in seconds (relative to the time the packet is sent) that the prefix is valid for the purpose of on-link determination. Preferred Lifetime: The length of time in seconds (relative to the time the packet is sent) that addresses generated from the prefix via stateless address autoconfiguration remains preferred. Prefix: An IP address or a prefix of an IP address. Prefix Length: contains the number of valid leading bits in the prefix. Figure 3 shows the proposed Prefix Option with the new 'H' flag. Here 'H' signifies handover of MR. When MNN's receive this flag, it indicates that the corresponding prefix is the one obtained by MR from PrRtAdv, and Fast MIPv6 can be triggered i.e. MNN's can immediately form their new prospective COA's and send FBU's. Figure 4 shows the operation of the method disclosed in this invention. It depicts control and data message flow. The complete procedure identifying when exactly the Prefix Option with the 'H' flag is sent, when the MNN's should trigger Fast MIPv6 and when the zero lifetime for the old prefix is to be sent, has been shown. Figure shows the following events in the appropriate order: MR gets PrRtAdv from R1 (with R2's prefix 4ffa::/64). MR sends RA to MNNs with 'H' flag set for the prefix 4ffa::/64. MR sends FBU to R1 as in normal FMIPv6. MNN gets the new prefix, and sends FBU to R1 through MR. As in FMIPv6, R1 and R2 exchange HI and Hack messages for MR and MNN's prospective new COA's. R1 sends the corresponding FBAcks to MR and MNN respectively. MR receives FBAck. MNN receives FBAck. MR undergoes handover and sends a zero lifetime for the old prefix 3ffa::/64 to MNN. MRsends FNA to R2. MNN receives Zero lifetime for the old prefix 3ffa::/64 and sends FNA to R2 through MR. MR and MNN start delivering packets using their respective new COA's (derived from the prefix 4ffa:: /64). Any packets destined to MR's or MNN's old COA's (derived from 3ffa:: /64) are tunneled by R1 to their new COA's respectively. This invention proposes a method to trigger Fast MIPv6 in the MNNs when the MR undergoes handover. Figure 1 depicts an example scenario where this method is helpful. MR, MNN's and the Access Routers (R1 and R2) have been assumed to be capable of Fast MIPv6. The following is the step-by-step operation of the invention: (Refer to Figure 3 and Figure.4) 1. MR gets proxy RA from R1 with the new prefix 4ffa::/64. 2. MR sends RA to MNNs with 'H' flag set for the prefix 4ffa::/64. 3. MR sends FBU to R1 as in normal FMIPv6. 4. MNN gets the new prefix, and sends FBU to R1 through MR. 5. As in FMIPv6, R1 and R2 exchange HI and Hack messages for MR and MNN's prospective new COA's. 6. R1 sends the corresponding FBAcks to MR and MNN respectively. 7. MR receives FBAck. 8. MNN receives FBAck. 9. MR undergoes handover and sends a zero lifetime for the old prefix 3ffa::/64to MNN. 10.MR sends FNA to R2. 11. MNN receives Zero lifetime for the old prefix 3ffa::/64 and sends FNA to R2 through MR. Data Packets: All packets destined to MNN's COA1 come to R1 and are tunneled to MNN's COA2. MNN reverse tunnels packets to CN through R1. This prevents loss of packets for the on-going session between MNN and CN when MR undergoes handover. Effects/Advantage(s) of the Invention: a. This method prevents loss of packets for the on-going session between MNNs and CNs when MR undergoes handover. b. This method reduces Hand-off latency for MNNs. c. This method requires no re-configuration or support of v6 routers. This method is very easy to implement and requires very minimal implementation changes to existing equipments. The above-presented description is of the best mode contemplated for carrying out the present invention. The manner and process of making and using it is in such a full, clear, concise and exact terms as to enable to any person skilled in the art to which it pertains to make and use this invention. New embodiments in particular, which also lie within the scope of the invention can be created, in which different details of the different examples can in a purposeful way be combined with one another. This invention is however, susceptible to modifications and alternate constructions from that disclosed above which are fully equivalent. Consequently, it is not the intention to limit this invention to the particular embodiment disclosed. On the contrary, the intention is to cover all modifications and alternate constructions coming within the spirit and scope of the invention as generally expressed by the following claims which particularly point out and distinctly claim the subject matter of the invention. GLOSSARY OF TERMS AND THEIR DEFINITIONS COA Care of Address FBAck Fast Binding Acknowledgement FBU Fast Binding Update FN Fixed Node FNA Fast Neighbor Advertisement. HAck Handover Acknowledge HI Handover Initiate HOA Home Address MNN Mobile Network Node MR Mobile Router NEMO Network Mobility PrRtAdv Proxy Router Advertisement. RA Router Advertisement RtSolPr Router Solicitation for Proxy Advertisement VMN Visiting Mobile Node References [RO] Route Optimization based on ND-Proxy for Mobile Nodes in IPv6 Mobile Networks. Jaehoon Jeong, Kyeongjin Lee, Jungsoo Park, Hyoungjun Kim [FMIPV6] Rajeev Koodli, "Fast Handovers for Mobile IPv6" ,draft-ietf-mipshop-fast-mipv6 , October, 2004. [NEMO] V.Devarapalli, R. Wakikawa, A. Petrescu, P. Thubert, "Network Mobility (NEMO) Basic Support Protocol", RFC 3963, January 2005. [MIPv6] D. Johnson, C. Perkins and J. Arkko, "Mobility Support in IPv6", RFC 3775, June 2004. [IPv6] Deering S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", RFC 2460, December 1998. WE CLAIM 1. A method of fast MIPV6 for mobile nodes in mobile networks with route optimizations based on ND-PROXY wherein the said method comprising the steps of: at the MR: (a) constructing RA with the prefix information containing a new flag; (b) triggering the sending of RA by MR as soon as PrRtAdv is received by MR; (c) passing the new prefix, contained in the PrRtAdv message, to the MNN's through RA; and (d) immediately sending zero lifetime for the old prefix after handover; at the MNN: (e) initiating FMIPv6 messages without any actual handover occurring, when prefix information with the 'H' flag is received. 2. A method as claimed in claim 1 wherein when MNN's receive the 'H' flag, the said MNN indicates that the corresponding prefix is the one obtained by MR from PrRtAdv, and Fast MIPv6 is triggered where MNN's immediately form new prospective COA's and send FBU's. 3. A method as claimed in claim 1 wherein MR gets PrRtAdv from first Access Router R1 and sends RA to MNNs with 'H' flag set. 4. A method as claimed in claim 1 wherein MR sends FBU to first Access Router R1 as in normal FMIPv6 and MNN gets the new prefix, and sends FBU to first Access Router R1 through MR. 5. A method as claimed in claim 1 wherein MR undergoes handover and immediately sends a zero lifetime for the old prefix to MNN. 6. A method as claimed in claim 1 wherein MR sends FNA to second Access Router R2 and MNN receives Zero lifetime for the old prefix and sends FNA to second Access Router R2 through MR. 7. A method of fast MIPV6 for mobile nodes in mobile networks with route optimizations based on ND-PROXY substantially as herein described particularly with reference to the drawings

Documents:

1068-CHE-2005 AMENDED PAGES OF SPECIFICATION 19-12-2012.pdf

1068-CHE-2005 AMENDED CLAIMS 19-12-2012.pdf

1068-CHE-2005 CORRESPONDENCE OTHERS 19-12-2012.pdf

1068-CHE-2005 FORM-13 19-12-2012.pdf

1068-CHE-2005 FORM-3 19-12-2012.pdf

1068-CHE-2005 POWER OF ATTORNEY 19-12-2012.pdf

1068-CHE-2005 AMENDED CLAIMS 11-07-2012.pdf

1068-CHE-2005 AMENDED PAGES OF SPECIFICATION 11-07-2012.pdf

1068-CHE-2005 EXAMINATION REPORT REPLY RECEIVED 11-07-2012.pdf

1068-CHE-2005 FORM-1 11-07-2012.pdf

1068-CHE-2005 FORM-13 19-06-2006.pdf

1068-CHE-2005 FORM-3 11-07-2012.pdf

1068-CHE-2005 FORM-5 11-07-2012.pdf

1068-CHE-2005 OTHER PATENT DOCUMENT 1 11-07-2012.pdf

1068-CHE-2005 OTHER PATENT DOCUMENT 11-07-2012.pdf

1068-CHE-2005 POWER OF ATTORNEY 11-07-2012.pdf

1068-che-2005-abstract.pdf

1068-che-2005-claims.pdf

1068-che-2005-correspondnece-others.pdf

1068-che-2005-description(complete).pdf

1068-che-2005-drawings.pdf

1068-che-2005-form 1.pdf

1068-che-2005-form 13.pdf

1068-che-2005-form 26.pdf