DESC:
FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

Title of invention:
METHOD AND SYSTEM TO ENABLE IP MOBILITY DURING Wi-Fi HANDOVER

Applicant:
Tata Consultancy Services Limited
A company Incorporated in India under the Companies Act, 1956
Having address:
Nirmal Building, 9th floor,
Nariman point, Mumbai 400021,
Maharashtra, India

The following specification particularly describes the embodiments and the manner in which it is to be performed.

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
[001] The present application claims priority to a Patent Application Serial Number 201621039194, filed before Indian Patent Office on November 17, 2016 and incorporates that application in its entirety.

TECHNICAL FIELD
[002] The embodiments herein generally relates to internet protocol (IP) mobility and, more particularly, the application provides a system and method to enable IP mobility during Wi-Fi handover.

BACKGROUND
[003] The growth of mobile devices throughout the world has seen a large surge in recent years. The use of such mobile devices for communication has increased proportionately. All mobile devices communicate via a network such as Wi-Fi network which is accessed through an access point. These mobile devices need to have easy and continuous access of the Wi-Fi network, irrespective of the access point used to access said Wi-Fi network, in order for seamless consumption of the networks by such mobile devices.

[004] IP mobility refers to the retention of mobile node IP address during a Wi-Fi handover across access points. This IP retention is needed for uninterrupted session of applications like VOIP or video conferencing.

[005] Traditional approach for IP mobility involves mobile IP (IETF RFC 5944) that use multiple IP addresses (Home Address and Care of Address) per mobile node and establishment of IP tunnels between access points involved in the handover. Mobile IP technique is cumbersome and expensive. Furthermore most of the prior art involves the use of two IP addresses (home and care of addresses) to be used per mobile node.

[006] Prior art literature has illustrated method for IP mobility during Wi-Fi handover however an efficient and effective method for the same is still considered a major challenge due to several drawbacks, including those mentioned above.

SUMMARY
[007] The following presents a simplified summary of some embodiments of the disclosure in order to provide a basic understanding of the embodiments. This summary is not an extensive overview of the embodiments. It is not intended to identify key/critical elements of the embodiments or to delineate the scope of the embodiments. Its sole purpose is to present some embodiments in a simplified form as a prelude to the more detailed description that is presented below.

[008] In view of the foregoing, the disclosure provides a method and system to enable IP mobility during Wi-Fi handover. According to the subject matter disclosed herein a Wi-Fi Network is created with more than one access points connected through an openflow switch. The openflow switch is managed and controlled by a software-defined networking (SDN) controller on a remote server or host. This remote server or host server also runs a remote and centralized radius server application for authorization of mobile node of a mobile device connected to the access points. In an embodiment the access points may be Wi-Fi routers.

[009] In an embodiment of the invention a mobile device which has a static/dynamic IP is connected to the first access point where authentication is done by the remotely running remote and centralized radius server application. The mobile device further accesses at least one media/ content online from a content server. When the mobile changes location and tries to connect to the second access point this connection is authorized by the remote and centralized radius server application. The remote and centralized radius server stores this information in a radius logs. The SDN controller reads radius logs and is aware of the movement of the mobile node from the first access point to the second access point. The SDN controller writes rules on the openflow switch for uninterrupted content/media transfer to the mobile device now connected to the second access point. Both the first and the second access points are enabled such that they support a mobile node IP associated with the mobile device.

BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The foregoing summary, as well as the following detailed description of preferred embodiments, are better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings exemplary constructions of the invention; however, the invention is not limited to the specific methods and system disclosed. In the drawings:

[0011] Figure 1 illustrates a network implementation of a system to enable IP mobility during Wi-Fi handover according to an embodiment of the subject disclosed herein;

[0012] Figure. 2 illustrates the system to enable IP mobility during Wi-Fi handover, in accordance with an embodiment of the subject matter disclosed herein;

[0013] Figure 3 illustrates an example of a network implementation to enable IP mobility during Wi-Fi handover according to an embodiment of the subject disclosed herein;

[0014] Figure 4 illustrates a sequence diagram to enable IP mobility during Wi-Fi handover according to an embodiment of the subject disclosed herein; and

[0015] Figure 5(a) and 5(b) illustrates a method to enable IP mobility during Wi-Fi handover, in accordance with an embodiment of the subject matter disclosed herein.

DETAILED DESCRIPTION
[0016] Some embodiments of this invention, illustrating all its features, will now be discussed in detail.

[0017] The words "comprising," "having," "containing," and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items.

[0018] It must also be noted that as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Although any systems and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present invention, the preferred, systems and methods are now described.

[0019] The disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms.

[0020] The elements illustrated in the Figures inter-operate as explained in more detail below. Before setting forth the detailed explanation, however, it is noted that all of the discussion below, regardless of the particular implementation being described, is exemplary in nature, rather than limiting. For example, although selected aspects, features, or components of the implementations are depicted as being stored in memories, all or part of the systems and methods consistent with the attrition warning system and method may be stored on, distributed across, or read from other machine-readable media.

[0021] The techniques described above may be implemented in one or more computer programs executing on (or executable by) a programmable computer including any combination of any number of the following: a processor, a storage medium readable and/or writable by the processor (including, for example, volatile and non-volatile memory and/or storage elements), plurality of input units, and plurality of output devices. Program code may be applied to input entered using any of the plurality of input units to perform the functions described and to generate an output displayed upon any of the plurality of output devices.

[0022] Each computer program within the scope of the claims below may be implemented in any programming language, such as assembly language, machine language, a high-level procedural programming language, or an object-oriented programming language. The programming language may, for example, be a compiled or interpreted programming language. Each such computer program may be implemented in a computer program product tangibly embodied in a machine-readable storage device for execution by a computer processor.

[0023] Method steps of the invention may be performed by one or more computer processors executing a program tangibly embodied on a computer-readable medium to perform functions of the invention by operating on input and generating output. Suitable processors include, by way of example, both general and special purpose microprocessors. Generally, the processor receives (reads) instructions and data from a memory (such as a read-only memory and/or a random access memory) and writes (stores) instructions and data to the memory. Storage devices suitable for tangibly embodying computer program instructions and data include, for example, all forms of non-volatile memory, such as semiconductor memory devices, including EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROMs. Any of the foregoing may be supplemented by, or incorporated in, specially-designed ASICs (application-specific integrated circuits) or FPGAs (Field-Programmable Gate Arrays). A computer can generally also receive (read) programs and data from, and write (store) programs and data to, a non-transitory computer-readable storage medium such as an internal disk (not shown) or a removable disk.

[0024] Any data disclosed herein may be implemented, for example, in one or more data structures tangibly stored on a non-transitory computer-readable medium. Embodiments of the invention may store such data in such data structure(s) and read such data from such data structure(s).

[0025] The present application provides a method and system to enable IP mobility during Wi-Fi handover. It would be appreciated that the IP mobility during Wi-Fi handover is also known as seamless IP-layer handover (L3 handover) in wireless local area network.

[0026] Referring now to Figure 1, a system 100 for enabling internet protocol (IP) mobility within a wireless local area networking. In one aspect of the system 100, one or more features of an appliance may be inferred from aggregate power measurements. In one aspect the steps for inferring features of an appliance from aggregate power measurement comprises a) data acquisition, b) appliance feature extraction and c) Inference and learning. Further, the features may be classified as a) Steady state features and b) Transient features. In another aspect of the subject matter disclosed herein an inference mechanism needs to distinguish between steady state features and transient features on an appliance and also be able to distinguish these features for multiple appliances. In an aspect of the system 100 the distinction between steady state and transient features is made without trading off the sampling rate and hence reduce data acquisition and component costs. Further this leads to reduction of training demands thereby reducing the data storage and data processing costs.

[0027] Although the present subject matter is explained considering that the server is implemented as a computing system, it may be understood that the server may also be implemented as a variety of computing systems, such as a laptop computer, a desktop computer, a notebook, a workstation, a mainframe computer, a server, a network server, a tablet, a mobile phone, and the like. In one implementation, the server may be implemented in a cloud-based environment. According to an embodiment, the system may be implemented with the vehicle. Further, the server may track the activities of the system 100 and the system 100 is communicatively coupled to the server through a network.

[0028] In one implementation, the network is a wireless network. The network can be implemented as one of the different types of networks, such as intranet, local area network (LAN), wide area network (WAN), the internet, and the like. The network may either be a dedicated network or a shared network. The shared network represents an association of the different types of networks that use a variety of protocols, for example, Hypertext Transfer Protocol (HTTP), Transmission Control Protocol/Internet Protocol (TCP/IP), Wireless Application Protocol (WAP), and the like, to communicate with one another. Further the network 106 may include a variety of network devices, including routers, bridges, servers, computing devices, storage devices, and the like.

[0029] In one embodiment, the system 100 comprises a Software-defined networking (SDN) controller (102), a remote and centralized remote and centralized radius server (104) and a content server (106). The SDN controller (102), the remote and centralized radius server (104) and the content server (106) are connected using openflow switch (108).

[0030] In the preferred embodiment, the SDN controller (102) is configured to control the one or more openflow switches. The SDN controller (102) controls one or more network elements for data packet forwarding to one or more access points. The SDN controller (102) reconfigures the network to redirect the content from the content server (106) to mobile device (114) which has moved to the second access point.

[0031] In the preferred embodiment, the mobile device (114) connects to a first access point (110) from a first location. The mobile device (114) is connected to the first access point (110) using an IP address associated with the mobile device (114). It would be appreciated that the IP address includes static IP address and dynamic IP address. The IP address is authenticated by the remote and centralized radius server. Once a connection is established post authentication, the content server (106) starts sending content to the mobile device (114).

[0032] In the preferred embodiment atleast one openflow switch (108) of one or more openflow switches of the network are configured to allow the flow of data packets from the content server (106) to the mobile device (114). Openflow switch is a network element with an openflow agent running on it. It communicates with the SDN controller using openflow protocol. SDN controller can program the openflow switch by adding and deleting openflow rules (flows) to forward data packets through its ports. For example, the openflow protocol version used here is openflow 1.0 although higher versions such as openflow 1.3 or 1.5 can also be used.

[0033] In the preferred embodiment, the remote and centralized radius server (104) is configured for authentication of mobile device (114) connected to one or more access points. The radius server has to be configured with the list of access points and their IP addresses which will connect to it. Moreover, the username and password of the mobile nodes too have to be set at the radius server. For example, if the radius server listens on UDP port 1812 for authentication and authorization and 1813 port for accounting. Access points are configured with the IP address and port numbers of radius server for their interworking. The access points forward mobile node user authentication requests to the radius server.

[0034] In the preferred embodiment the content server (106) may be a video streaming server such as VLC server. In another embodiment the mobile user may consume the content using a content client application such as VLC client application. This content streaming is supported by two default Openflow rules at the openflow switch (108). The mobile device (114), then moves towards a second access point (112) and gets connected to the second access point. This movement is notified at the remote and centralized radius server (104) and retained on the remote and centralized radius server logs. On such notification being recorded on the remote and centralized radius server logs, the SDN controller (102) writes new flow to enable flow of content in the form of packet data via the openflow switch (108) from the content server (106) to the mobile device (114) which is now connected to the second access point (112).

[0035] In the preferred embodiment, the first access point (110) and the second access point (112) are enabled such that both access points can support the mobile node IP for the mobile device (114). The mobile device (114) therefore does not cease to consume content via the content server (116) during the Wi-Fi handover from the first access point (110) to the second access point (112). In an embodiment the access points may be Wi-Fi routers.

[0036] It will be obvious to a person skilled in the art that the system explained using Fig. 2 may be implemented using more than one mobile device and a plurality of access points. The description of Fig. 2 is intended to explain the working of the system disclosed herein but does not limit the scope and implementation of the system.

[0037] Referring fig. 3, as an example, explains the disclosed method using one mobile device and two access points, it will be clear to a person skilled in the art that the method may be applied using a plurality of devices and access point and may be implemented in different forms. The above steps are in no way intended to limit the scope of the instant disclosure and may not be treated as such.

[0038] Referring fig. 4, a sequence diagram for the mobile node attachment with the network, subsequent media streaming from the content node and the final handover is shown.

[0039] Referring now to Fig. 5(a) and 5(b), a flow chart illustrating the method to enable IP mobility during Wi-Fi handover. It would be appreciated that the IP mobility during Wi-Fi handover is also known as seamless IP-layer handover (L3 handover) in wireless local area network.

[0040] At the step 502 the SDN controller configures one or more openflow switches to provide the network connectivity between a plurality of access points and a remote and centralized radius server. The SDN controller (102) controls one or more network elements for data packet forwarding to one or more access points. The SDN controller (102) reconfigures the network to redirect the content from the content server (106) to mobile device (114) which has moved to the second access point.

[0041] At the step 504 the mobile device connects to a first access point using the IP address. In an embodiment the first access point may be a Wi-Fi router. Further an SDN Controller, a remote and centralized radius server and a content server are connected by means of an openflow switch wherein said openflow switch connects and allows the flow of content in the form of packet data to the mobile node via Wi-Fi router.

[0042] At the step 506, the SDN controller monitors the radius log to track the location of the mobile device. On such notification being recorded on the remote and centralized radius server logs, the SDN controller (102) writes new flow to enable flow of content in the form of packet data via the openflow switch (108) from the content server (106) to the mobile device (114) which is now connected to the second access point (112).

[0043] At the step 508, the radius server authenticates the mobile device using the user credentials. For example, if the radius server listens on UDP port 1812 for authentication and authorization and 1813 port for accounting. Access points are configured with the IP address and port numbers of radius server for their interworking. The access points forward mobile node user authentication requests to the radius server.

[0044] At the step 510, the SDN controller configures the network to provide network connectivity between content server and the mobile device through atleast one of the plurality of access points of the wireless local area network.

[0045] At the step 512 the mobile device starts consuming content in the form of packet data from the content server, wherein the content from the content server is routed through the atleast one openflow switch of the one or more openflow switches using default openflow rules set by the SDN controller.

[0046] At the step 514 the mobile device moves towards a second access point of the plurality of access points and connects to the second access point using the same IP which is authenticated by the remote and centralized radius server. The second access point is also connected to the SDN controller, the remote and centralized radius server and the content server.

[0047] In an embodiment the method may be implemented using a plurality of access points and a plurality of mobile devices wherein each access point is enabled to support the mobile node IP of each mobile node which connects to the access point.

[0048] At the step 516 the remote and centralized radius server is notified the movement of the mobile device and authenticates the mobile device. The remote and centralized radius server stores this information in a remote and centralized radius server log. The SDN controller access the remote and centralized radius server log to track the movement of the mobile device.

[0049] Lastly at the step 518 the SDN controller reconfigures the openflow network to reroute the streaming data packets to the second access point thus the mobile device gets uninterrupted data streaming although the mobile device has moved from the first access point to the second access point. The mobile device therefore does not cease to consume content from the content server during the Wi-Fi handover from the first access point (110) to the second access point (112).

[0050] The embodiments of present disclosure herein addresses unresolved problem of retaining of Mobile Node IP address during a Wi-Fi handover across Access Points. This IP retention is needed for uninterrupted session of applications like VOIP or video conferencing.

[0051] The system and method disclosed herein enables IP mobility when a mobile device connected to one access point connects to a second access point wherein the content consumption is not impacted by such handover. The disclosed system and method use an SDN controller, a remote and centralized radius server, a content server and an openflow switch connected with the access points, wherein the SDN controller is enabled to write new flows to allow flow of content from the content server to the mobile device via the openflow switch during Wi-Fi handover.

,CLAIMS:
1. A system for enabling internet protocol (IP) mobility within a wireless local area networking, the system comprising:
a mobile device within a wireless local area network is configured to connect with one or more access points;
one or more openflow switches are configured to allow the flow of packets from a content server to the mobile device;
a software-defined networking (SDN) controller is configured to control the one or more openflow switches, wherein the SDN controller controls one or more network elements for packet forwarding to one or more access points; and
a remote and centralized radius server is configured for authentication of mobile device connected to one of the access points.

2. The system claimed in claim 1, wherein the SDN controller reconfigures the network to redirect the content from the content server to mobile device which has moved to the second access point.

3. The system claimed in claim 1, wherein the mobile device are allowed to retain original internet protocol address while moving from first access point to second access point to achieve the seamless IP-layer handover (L3 handover) in wireless local area network.

4. The system claimed in claim 1, wherein the access points includes physical access points and virtual access points.

5. The system claimed in claim 1, wherein the access points supports independent internet protocol subnets.

6. The system claimed in claim 1, wherein the internet protocol address of the mobile node includes static internet protocol address and dynamic internet protocol address.

7. A method for enabling internet protocol mobility within a wireless local area networking, wherein the method comprising steps of:
configuring the one or more openflow switches to provide the network connectivity between a plurality of access points and a remote and centralized remote and centralized radius server using the SDN controller;
connecting a mobile device to first access point of the plurality of access points of the wireless local area network through a remote and centralized remote and centralized radius server;
monitoring the radius log to track the location of the mobile device using SDN controller;
authenticating mobile device by remote and centralized radius server using user credentials;
configuring the network to provide network connectivity between content server and mobile device through the access point using SDN controller;
streaming packet data from the content server to the mobile device, wherein the content from the content server is routed through the atleast one openflow switch of one or more openflow switches;
authenticating the mobile device upon moving to a second access point using the remote and centralized radius server, wherein the movement of the mobile device is tracked by the SDN controller through the radius logs; and
reconfiguring the openflow network to reroute the streaming data packets to the second access point using the SDN controller thus the mobile device gets uninterrupted data streaming although it has moved from the first access point to the second access point.

8. The method claimed in claim 7, wherein the mobile device using the same internet protocol address while moving from first access point to second access point.

9. The method claimed in claim 7, wherein the movement of the mobile device from first access point to second access point is notified at remote and centralized radius server.

10. The method claimed in claim 7, wherein the content includes audio data, video data and any other data formats.