Title of Invention

A METHOD FOR FAST HANDOFF BASED ON LAYER 3 PROTOCOL TYPE

Abstract The invention explains a method for fast handoff based on L3 protocol type in a communication system where the mobile node (MN) is doing handoff from one cell to other cell. The method involves proactively finding the L3 protocol type of the available next access points during handoff and selecting suitable access point whose L3 capabilities are good match to the preferences of the mobile node. The method finally involves proceeding with the corresponding fast handoff methods based on L3 protocols supported by the chosen access point for handoff.
Full Text FIELD OF THE INVENTION
The present invention, in general, relates to the field of mobility management and in particular finding suitable access point/network point of attachment during handoff based on Layer 3 protocol type. More particularly, the present invention relates to a method for fast handoff based on Layer 3 protocol type.
DESCRIPTION OF RELATED ART
No fast handoff scheme discusses about handoff based on L3 protocol type of next network point of attachment
LIMITATIONS
The Mobile node can get associated with the access point where Layer 3 protocol mismatch can occur.
SUMMARY OF THE INVENTION
This method proposes a way to detect L3 protocol supported by the next network point of attachment during handoff proactively.
It utilizes the concept and messages defined in [FMIPv6] protocol to get the L3 information of the candidate access points. The layer 3 protocol type thus

detected is used in making handoff decision.
This method reduces handoff latency in cases where the mobile node will handoff to an AP who's supported L3 protocol does not match with MN.
Accordingly, this invention explains a method for fast handoff based on L3 protocol type in a communication system where the mobile node(MN) is doing handoff from one cell to other cell comprising the steps of:
(a) proactively finding the L3 protocol type of the available next access points during handoff;
(b) selecting suitable access point whose L3 capabilities are good match to the preferences of the mobile node; and
(c) proceeding with the corresponding fast handoff methods based on L3 protocols supported by the chosen access point for handoff.
Proactively finding the L3 protocol type of the available next access points during handoff involves:
(a) MN deciding to handoff to next suitable access point when the signal strength from access point PAP has weakened;
(b) MN finding available APs based on link specific events during handoff when the said MN is still connected to its current subnet;
(c) MN sending PrRotSol request to its current access router to get the subnet information of these access points;
(d) Previous Access Router (PAR) sending a PrRtAdv message which

contains information about L3 protocols supported by each access point, along with the subnet information; and
(e) Previous Access Router (PAR) getting the information about neighboring access points either statically by manual configuration or dynamically from an information server.
PAR stores the L3 protocol type, link layer address, IP address, prefix information of the access router of its neighboring access points. After getting the L3 capabilities of the available APs, MN choose an AP for association whose capabilities are good match to its preferences. MN, after deciding which AP to handoff, proceeds with corresponding fast handoff methods based on its L3 type.
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 DRAWING
Figure 1 shows a possible scenario where this invented method is applicable. PAP is the access point with which MN is currently associated. In this figure NAP is the possible neighboring access point with which MN may be associated.
DETAILED DESCRIPTION OF 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.
The detailed operation of the invention is as follows:
Figure 1 depicts the example scenario where the proposed method is applicable. This method can be used in addition to other methods to make a better decision. It consists of two access routers PAR and NAR, two access points PAP and NAP and a mobile node MN. PAR and NAR are subnet routers and are connected to the internet. PAP and NAP provide wireless services to the mobile nodes in their geographical region referred to as cell. They act as bridge between access routers and mobile nodes.
The mobile node MN generally communicates with the access point in that cell in which it is currently located. As the mobile node MN travels from cell to cell, the communication from the access point AP in one cell is handed over to the access point AP in a neighboring cell. This procedure is called handoff.

In Fig.1, initially MN is in contact with access point PAP. When the signal strength from access point PAP has weakened, MN will decide to handoff to next suitable access point.
MN will find available APs based on some link specific events during handoff when it is still connected to its current subnet. MN sends PrRotSol request to its current access router to get the subnet information of these access points. As a response to RtSolPr, PAR sends a PrRtAdv message which contains information about L3 protocols supported by each access point such as IPv4, IPv6, IPX etc., along with the subnet information.
PAR can get the information about neighboring access points either statically or dynamically.
In the static case, information can be manually configured at each access router. Many ways are proposed to get the neighboring access points information dynamically inside a domain. One way is using some information server which contains all the information about neighboring access points for each access point in an enterprise network. Any node can get the neighboring access points information from this server.
PAR will store the L3 protocol type, link layer address, IP address, prefix information of the access router of its neighboring access points

After getting the L3 capabilities of the available APs, MN can choose an AP for association whose capabilities are good match to its preferences. MN after deciding to which AP it should handoff, it can proceed with corresponding fast handoff methods based on its L3 type.
ADVANTAGES
The chances of MN connecting to an access point with layer 3 mismatch will be avoided.
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 therefrom.

GLOSSARY OF TERMS AND DEFINITIONS THEREOF
MN - Mobile Node
AP - Access Point
PAR - Previous Access Router
NAR - Next Access Router
PAP - Previous Access Point
NAP - Next Access Point
IP- Internet Protocol
PrRtrSol - Router Solicitation for Proxy Advertisement
PrRtrAdv - Proxy Router Advertisement
REFERENCES
]FMTPV6] Rajeev Koodli “Fast Handovers for Mobile lPv6”, RFC 4068, July 2004.
WE CLAIM
1. A method for fast handoff based on L3 protocol type in a communication system where the mobile node (MN) is doing handoff from one cell to other cell comprising the steps of:
(a) proactively finding the L3 protocol type of the available next access points during handoff;
(b) selecting suitable access point whose L3 capabilities are good match to the preferences of the mobile node; and
(c) proceeding with the corresponding fast handoff methods based on L3 protocols supported by the chosen access point for handoff.
2. A method as claimed in claim 1 wherein proactively finding the L3 protocol type of the available next access points during handoff involves:
(a) MN deciding to handoff to next suitable access point when the signal strength from access point PAP has weakened;
(b) MN finding available APs based on link specific events during handoff when the said MN is still connected to its current subnet;
(c) MN sending PrRotSol request to its current access router to get the subnet information of these access points;
(d) Previous Access Router (PAR) sending a PrRtAdv message which contains information about L3 protocols supported by each access point, along with the subnet information; and
(e) Previous Access Router (PAR) getting the information about neighboring

access points either statically by manual configuration or dynamically from an information server.
3. A method as claimed in claim1 wherein PAR stores the L3 protocol type, link layer address, IP address, prefix information of the access router of its neighboring access points.
4. A method as claimed in claimi wherein after getting the L3 capabilities of the available APs, MN choose an AP for association whose capabilities are good match to its preferences.
5. A method as claimed in claimi wherein MN after deciding which AP to handoff, proceed with corresponding fast handoff methods based on its L3 type.
6. A method for fast handoff based on L3 protocol type in a communication system substantially described particularly with reference to the accompanying drawings.

Documents:

2485-CHE-2006 POWER OF ATTORNEY 13-01-2014.pdf

2485-CHE-2006 AMENDED PAGES OF SPECIFICATION 12-09-2013.pdf

2485-CHE-2006 AMENDED PAGES OF SPECIFICATION 31-12-2013.pdf

2485-CHE-2006 AMENDED CLAIMS 12-09-2013.pdf

2485-CHE-2006 AMENDED CLAIMS 30-12-2013.pdf

2485-CHE-2006 AMENDED CLAIMS 31-12-2013.pdf

2485-CHE-2006 AMENDED PAGES OF SPECIFICATION 30-12-2013.pdf

2485-CHE-2006 CORRESPONDENCE OTHERS 13-01-2014.pdf

2485-CHE-2006 EXAMINATION REPORT REPLY RECEIVED 12-09-2013.pdf

2485-CHE-2006 EXAMINATION REPORT REPLY RECEIVED 30-12-2013.pdf

2485-CHE-2006 FORM-1 13-01-2014.pdf

2485-CHE-2006 FORM-13 12-09-2013.pdf

2485-CHE-2006 FORM-5 12-09-2013.pdf

2485-CHE-2006 OTHER PATENT DOCUMENT 12-09-2013.pdf

2485-CHE-2006 OTHERS 12-09-2013.pdf

2485-CHE-2006 POWER OF ATTORNEY 12-09-2013.pdf

2485-CHE-2006 EXAMINATION REPORT REPLY RECEIVED 31-12-2013.pdf

2485-CHE-2006 FORM-13 12-12-2013.pdf

2485-CHE-2006 FORM-18.pdf

2485-CHE-2006 POWER OF ATTORNEY 30-12-2013.pdf

2485-CHE-2006 POWER OF ATTORNEY 31-12-2013.pdf

2485-CHE-2006 FORM 18.pdf

2485-CHE-2006 FORM-13 16-12-2013.pdf

2485-che-2006-abstract.pdf

2485-che-2006-claims.pdf

2485-che-2006-correspondnece-others.pdf

2485-che-2006-description(complete).pdf

2485-che-2006-drawings.pdf

2485-che-2006-form 1.pdf

2485-che-2006-form 26.pdf


Patent Number 258861
Indian Patent Application Number 2485/CHE/2006
PG Journal Number 07/2014
Publication Date 14-Feb-2014
Grant Date 11-Feb-2014
Date of Filing 29-Dec-2006
Name of Patentee SAMSUNG R&D INSTITUTE INDIA - BANGALORE PRIVATE LIMITED
Applicant Address #2870 ORION BUILDING BAGMANE CONSTELLATION BUSINESS PARK OUTER RING ROAD DODDANEKUNDI CIRCLE MARATHAHALLI POST BANGALORE -560037
Inventors:
# Inventor's Name Inventor's Address
1 SYAM MADANAPALLI EMPLOYED AT SAMSUNG INDIA SOFTWARE OPERATIONS PVT LTD., HAVING ITS OFFICE AT, BAGMANE LAKEVIEW, BLOCK B' NO.66/1, BAGMANE TECH PARK, C V RAMAN NAGAR, BYRASANDRA, BANGALORE-560093, KARNATAKA, INDIA
2 WABLE R.U EMPLOYED AT SAMSUNG INDIA SOFTWARE OPERATIONS PVT LTD., HAVING ITS OFFICE AT, BAGMANE LAKEVIEW, BLOCK B' NO.66/1, BAGMANE TECH PARK, C V RAMAN NAGAR, BYRASANDRA, BANGALORE-560093, KARNATAKA, INDIA
3 SUBBA REDDY EMPLOYED AT SAMSUNG INDIA SOFTWARE OPERATIONS PVT LTD., HAVING ITS OFFICE AT, BAGMANE LAKEVIEW, BLOCK B' NO.66/1, BAGMANE TECH PARK, C V RAMAN NAGAR, BYRASANDRA, BANGALORE-560093, KARNATAKA, INDIA
4 SUREKHA BIRUDURAJU EMPLOYED AT SAMSUNG INDIA SOFTWARE OPERATIONS PVT LTD., HAVING ITS OFFICE AT, BAGMANE LAKEVIEW, BLOCK B' NO.66/1, BAGMANE TECH PARK, C V RAMAN NAGAR, BYRASANDRA, BANGALORE-560093, KARNATAKA, INDIA
PCT International Classification Number H04B7/185
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA