Title of Invention

METHOD OF ROUTE OPTIMIZATION BETWEEN MOBILE NODE AND ROAMING HOME AGENT IN MOBILE INTERNET PROTOCOL VERSION 6 NETWORK

Abstract

The current invention describes a method for optimizing routing of packets between a mobile node (MN) and a roaming home agent (HA) in a Mobile IPv6 network.The techniques take advantage of the Mobile IPv6 support at the MN and HA for avoiding the extra tunneling and extra path traversal for the packets between MN and CN. When HA receives a tunneled packet from HAJHA sent from MN to CN, it verifies whether the present address of communication is the Care-of-Address (CoA) of MN from the Binding Cache List. HA identifies the home address of the MN from the Binding Cache List and then initiates a Return Routability (RR) Procedure. After successful RR Procedure, the packets from MN to CN traverse from MN to HA and then to HA_HA and finally to CN, while the packets from CN to MN traverse from CN to HA_HA and then to HA and finally to MN.

Full Text

FIELD OF THE INVENTION The invention is related to mobile communication technology. Further, it deals with the method of optimizing path between MN and CN in case of Home Agent (HA) Mobility in MIPv6 network. More particularly, this invention relates method of route optimization between MN and roaming HA IN MIPv6 network. DESCRIPTION OF RELATED ART The MIPv6 technique [MIPV6] facilitates communication of a mobile host to continue when it moves from one network to another. The mobile host informs the Home Agent (HA) of its current location and any packets sent to Home Address of MH is received by HA and passed to MN through an IPv6-over-IPv6 tunnel. The MIPv6 technique also supports Route Optimization in case CN supports the RO technique. In case CN does not supports MIPv6, all packets to and from MN goes via HA of MN. In case the HA moves from its home network, it informs its own Home Agent (HA_HA) about its location and all packets meant for HA comes and goes via HA_HA. This traversal results in extra path for each packet that is exchanged between MN and CN as explained in next section. Figure 1 depicts a scenario when a mobile host has moved to foreign network followed by movement of its Home Agent also to a foreign network. Both the MN and HA has updated their Home Agents, i.e. HA and HAJHA respectively, with Binding Update Message about it's current location. We also assume here that CN does not support MIPv6 technique, hence every packet going between MN and CN has to be traversed via HA. In such a scenario a packet exchange between MN and CN takes place as follows as shown in Figure 1. 1. MN sends an encapsulated packet to HA destined for CN, received by HAJHA as HA moved to foreign location. 2. HAJHA tunnels the packet to HA using another IPv6-over-IPv6 encapsulation on it. 3. HA removes both the encapsulated header, and identifies that the packet is destined for CN. It adds an IPv6-over-IPv6 encapsulation and sends the packet to HAJHA to be sent further to CN. 4. HAJHA removes the IPv6 encapsulation and sends the packet to CN, originally sent from MN. 5. A packet from CN is sent to HoA of MN, which is supposed to be received by HA. Since HA is roaming, HAJHA receives the packet on behalf of HA. 6. The received packet from CN is encapsulated and send to HA. 7. HA, after removing the encapsulation, identifies that the packet is meant for MN encapsulates the packet as per MIPv6 to be sent to MN CoA. Since the packet has to be sent to via HAJHA the packet gets an added encapsulation on top of it. The packet is sent to HAJHA. 8. HA_HA removes the outer header and sends the packet to MN to its CoA. MN removes the outer header and receives the packet sent for its HoA sent from CN. However in the present scenario, in case CN does not support MIPv6 RO techniques, the packet exchanged between MN and CN does not undergo any optimization. The present art takes no advantage of the fact that both the HA and MN support RO techniques. In patent number US 20020015396, it describes a method for transmitting a data packet from a mobile node to a correspondent node through a foreign agent while maintaining security is disclosed. A correspondent node transmits a first data packet for communication with a mobile node to the home agent. Upon receipt of the first data packet from the home agent, the foreign agent transmits the first data packet to the mobile node through a radio channel. The home agent transmits the IP address of the foreign agent to the correspondent node after transmitting the first data packet to the foreign agent. The correspondent node transmits tunneling indication information indicating whether it can decapsulate a data packet encapsulated by the foreign agent to the foreign agent after receiving the IP address of the foreign agent from the home agent. The foreign agent encapsulates subsequent data packets received from the mobile node with a tunneling IP header for reverse tunneling and transmits the encapsulated data packets to the correspondent node, after receiving the tunneling indication information from the correspondent node. However tunneling and packet traversal between foreign agent and correspondent node directly (without routing through home agent) may be analogous to the path optimization described in the current techniques. SUMMARY OF THE INVENTION Mobile IPv6 enables a Mobile Node to maintain its connectivity to the Internet when moving from one network to another. The movement is notified to HA which helps in sending and receiving packets to MN at the foreign location. When HA moves to foreign network, it updates his Home Agent (HAJHA) about it's present location. The patent deals with the optimization of path between MN and HA in case MN's HA is not in it's home network. The applicability of patent is in the case where CN does not support MIPv6 Route Optimization. It is the principal object of the invention to invent a novel method of optimizing path between MN and CN in case of Home Agent (HA) Mobility in MIPv6 network, which is unique. It is another object of the invention to invent and design a novel method for optimizing the path between MN and CN in case HA moves to foreign location with very minimal implementation changes to existing equipments. It is another object of the invention to invent a novel method for verifying the tunneled packets by HA, to see if it needs to initiate the RO procedure as per MIPv6, and if RO needs to be initiated, it first finds out the Care of Address by extracting the source address from the inner IPv6 header of the received packet. It is yet another object of the invention to invent a novel method to find the Home Address of the MN using the Binding List Cache and triggering the Return Routing Procedure using the HoA of MN thereby enabling MN to communicate with HA using HA's Care of Address, and to receive packet directly from HA without any communication going through Home Agent of HA. Accordingly, this invention explains a method of route optimization between MN and roaming HA in MIPv6 network comprising the steps of: (a) HA identifying that, the first packet has been communicated via HA_HA on receiving the said first packet from MN; (b) doing an RO with MN as per MIPv6 on receiving the said first packet from MN; (c) triggering RR Procedure using the Care of Address of MN by the tunnel packet; (d) HA using its Binding Cache Entry to first find out the HoA of MN; (e) HA initiating RR procedure with MN, on gaining the knowledge of MN's HoA; (f) Obtaining RO for any packet going between MN and HA, on successful RR Procedure; and (g) HA receiving the packet directly from MN at HA's CoA. When HA receives tunneled packet from its Home Agent (HA_HA) and HA verifies if the said HA needs to initiate the RO procedure as per MIPv6 for the received tunneled packet. If RO is initiated, the said RO first finds out the Care of Address by extracting the source address from the inner IPv6 header of the received packet. RO uses the Binding List Cache to find out the Home Address of the MN the said RO is communicating with. HA triggers Return Routability Procedure using the HoA of MN.and on successful RO, MN communicates with HA using HA's Care of Address, and receives packet directly from HA without any communication going through Home Agent of HA. The tunnel packet has the source as MN CoA. The HA sends the packet directly to MN using the Route Optimization technique. For packets to be communicated using HoA, the MN or HA the path through HA_HA is used. These and other objects, features and advantages of the present invention will become more apparent from the ensuing detailed description of the invention taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS Figure 1 shows the prior art depicting the communication between MN and CN with mobile HA. Figure 2 shows the Optimized path between MN and CN with mobile HA. Figure 3 shows the message exchange sequence to trigger optimization of path between MN and CN. 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 2 shows the optimized path that is used for an ongoing communication between MN and CN after we use the invention technique as explained in this document. The situation depicted is the case where both MN and HA are in foreign network and CN does not support RO techniques as according to [MIPv6]. Figure 3 shows the way the newly described mechanism take place to optimize the path between MN and CN. After a successful completion of all packet exchange, as according to this figure, the packets between MN and CN are exchanged as according to Figure 2. The invention proposes a method to do path optimization for packets exchanged between MN and CN when both MN and its HA are in foreign network. The following is the step-by-step operation of the invention as shown in figure 3: 1. The packets from either MN or CN goes as explained in the prior art. 2. On receiving the first packet from MN, HA identifies that it has been communicated via HA_HA and will do RO with MN as per [MIPv6]. 3. The tunnel packet has the source as MN CoA and if it triggers RR Procedure using the Care of Address of MN, the RR will fail as according to [MIPv6]. 4. Therefore, HA uses its Binding Cache Entry to first find out the HoA of MN. 5. On gaining the knowledge of MN's HoA, the HA initiates RR procedure with MN. 6. On successful RR Procedure, the RO is obtained for any packet going between MN and HA. 7. The HA then receives the packet directly from MN at HA's CoA. The HA also sends the packet directly to MN using the Route Optimization technique of [MIPv6]. However for packets to be communicated using HoA, the MN or HA may use the path through HAJHA according to [MIPv6]. The patent deals with optimizing the path between MN and CN by taking the advantage of MIPv6 Support at both the MN and HA. It will also be obvious to those skilled in the art that other control methods and apparatuses can be derived from the combinations of the various methods and apparatuses of the present invention as taught by the description and the accompanying drawings and these shall also be considered within the scope of the present invention. Further, description of such combinations and variations is therefore omitted above. It should also be noted that the host for storing the applications include but not limited to a microchip, microprocessor, handheld communication device, computer, rendering device or a multi function device. Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are possible and are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart there from. GLOSSARY OF TERMS AND DEFINITIONS THEREOF MN : Mobile Node HA: Home Agent HA_HA: Home Agent of HA HoA: Home Address CoA : Care of Address RO: Route Optimization IPv6 : Internet Protocol version 6 MIPv6 : Mobile IPv6 CN : Correspondant Node RR : Return Routability Procedure HoT1/CoT1/HoT/CoT: Messages as defined in [MIPv6] as part of RR Procedure. REFERENCES [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 route optimization between MN and roaming HA in MIPv6 network comprising the steps of: (a) HA identifying that, the first packet has been communicated via HA_HA on receiving the said first packet from MN; (b) doing an RO with MN as per MIPv6 on receiving the said first packet from MN; (c) triggering RR Procedure using the Care of Address of MN by the tunnel packet; (d) HA using its Binding Cache Entry to first find out the HoA of MN; (e) HA initiating RR procedure with MN, on gaining the knowledge of MN's HoA; (f) Obtaining RO for any packet going between MN and HA, on successful RR Procedure; and (g) HA receiving the packet directly from MN at HA's CoA. 2. A method as claimed in claim 1 wherein when HA receives tunneled packet from its Home Agent (HA_HA) and HA verifies if the said HA needs to initiate the RO procedure as per MIPv6 for the received tunneled packet. 3. A method as claimed in claim 1 wherein if RO is initiated, the said RO first finds out the Care of Address by extracting the source address from the inner IPv6 header of the received packet. 4. A method as claimed in claim 1 wherein RO uses the Binding List Cache to find out the Home Address of the MN the said RO is communicating with. 5. A method as claimed in claim 1 wherein HA triggers Return Routability Procedure using the HoA of MN.and on successful RO, MN communicates with HA using HA's Care of Address, and receives packet directly from HA without any communication going through Home Agent of HA. 6. A method as claimed in claim 1 wherein the tunnel packet has the source as MN CoA. 7. A method as claimed in claim 1 wherein the HA sends the packet directly to MN using the Route Optimization technique. 8. A method as claimed in claim 1 wherein for packets to be communicated using HoA, the MN or HA the path through HA_HA is used. 9. A method of route optimization between MN and roaming HA in MIPv6 substantially described particularly with reference to the accompanying drawings.

Documents:

2460-CHE-2006 AMENDED PAGES OF SPECIFICATION 01-04-2013.pdf

2460-CHE-2006 AMENDED CLAIMS 01-04-2013.pdf

2460-CHE-2006 EXAMINATION REPORT REPLY RECEIVED 01-04-2013.pdf

2460-CHE-2006 FORM-1 01-04-2013.pdf

2460-CHE-2006 FORM-13 01-04-2013.pdf

2460-CHE-2006 FORM-5 01-04-2013.pdf

2460-CHE-2006 OTHER PATENT DOCUMENT 01-04-2013.pdf

2460-CHE-2006 POWER OF ATTORNEY 01-04-2013.pdf

2460-CHE-2006 FORM 18.pdf

2460-che-2006-abstract.pdf

2460-che-2006-claims.pdf

2460-che-2006-correspondnece-others.pdf

2460-che-2006-description(complete).pdf

2460-che-2006-drawings.pdf

2460-che-2006-form 1.pdf

2460-che-2006-form 26.pdf