Title of Invention

METHOD TO PROVIDE MOBILITY BETWEEN 3GPP SYSTEM ARCHITECTURE EVOLUTION/LONG TERM EVOLUTION (SAE/LTE) AND OTHER ACCESS SYSTEMS USING THE IEEE 802.21 MEDIA INDEPENDENT HANDOVER FUNCTION

Abstract This invention relates to Mobility and Handover between heterogeneous wireless networks. More specifically, this invention provides a method to support handover between the 3GPP System Architecture Evolution/Long Term Evolution (SAE/LTE) and other access systems like the Universal Mobile Telecommunication System (UMTS), CDMA2000, Inter-working Wireless Local Area Networks (IWLAN) and the WiMAX access systems. The scope of the invention also covers the case when the UE is not capable of accessing both the SAE/LTE and other access systems simultaneously. This invention provides a system and method to perform Mobility between the access systems with optimized authentication procedure using security context transfer between the access systems, backward handover, i.e. reserving resources in the target access system before the handover and also minimize the data loss by buffering the data during the handover. More particularly this invention relates to method to provide mobility between 3gpp system architecture evolution/long term evolution (SAE/LTE) and other access systems using the IEEE 802.21 media independent handover function
Full Text FIELD OF THE INVENTION
This invention relates to Mobility and Handover between heterogeneous wireless networks. More specifically, this invention provides a method to support handover between the 3GPP System Architecture Evolution/Long Term Evolution (SAE/LTE) and other access systems like the Universal Mobile Telecommunication System (UMTS), CDMA2000, Inter-working Wireless Local Area Networks (IWLAN) and the WiMAX access systems.
The scope of the invention also covers the case when the UE is not capable of accessing both the SAE/LTE and other access systems simultaneously. This invention provides a system and method to perform Mobility between the access systems with optimized authentication procedure using security context transfer between the access systems, backward handover, i.e. reserving resources in the target access system before the handover and also minimize the data loss by buffering the data during the handover. More particularly this invention relates to method to provide mobility between 3gpp system architecture evolution/long term evolution (SAE/LTE) and other access systems using the IEEE 802.21 media independent handover function
DESCRIPTION OF RELATED ART
The radio access network (RAN), system architecture (SA) and the core terminal (CT) working groups of the third generation partnership project (3GPP) aim to develop a System Architecture Evolution/Long Term Evolution (SAE/LTE) architecture for next generation wireless systems. The SAE/LTE system is required to co-exist with the current second (2G) and third generation (3G) wireless systems, and in particular, support handovers between the existing systems and the newly evolved SAE/LTE system.
The SAE/LTE system is an evolution of the Third Generation Partnership Project (3GPP) UMTS Terrestrial Radio Access Network (UTRAN) system, in which the

main entities are the user equipment (UE), the evolved RAN consisting of an enhanced Node B (ENB) and an evolved packet core network consisting of a Mobility Management Entity (MME), User Plane Entity (UPE) and an Inter access system Anchor (Inter AS Anchor). Usually, the MME and UPE are co-located. The ENB of the EUMTS system is expected to have the features of the Node B and the radio network controller (RNC) of the legacy UTRAN system. The MME and UPE, between them, are expected to have the functions of the SGSN and GGSN of the legacy UTRAN systems. The integration of the SAE/LTE system with the existing 2G/3G Generalized Packet Radio Service (GPRS) and Universal Mobile Telecommunication Systems (UMTS) is shown in the Figure 1.
The entities in Figure 1 are as follows
• The GSM EDGE Radio Access Network (GERAN) consists of the Base Transceiver Station (BTS) and the Base Station Controller (BSC)
• The UTRAN consists of the Node B and the Radio Network Controller (RNC).
• The Evolved RAN is the Enhanced Node B (ENB)
• The Mobility management entity (MME) manages UE context and other control plane functions for the LTE UE.
• The User Plane Entity (UPE) manages all user plane functions for LTE UE. The architecture shows MME and UPE combined into one node. However, it does not preclude a separation. When separated, it is possible that the UPE is co-located with the SAE anchor or in ENB. It is also possible that UPE and GGSN are co-located.
• The Non-3GPP access system depicts a scenario 3 Inter worked WLAN (I- WLAN) or a Wi-MAX or a 3GPP2 access system.
• The Home Subscription Server (HSS) consists of the Home Location Register (HLR) and the Authentication Center (AuC).
• The SAE Anchor acts as the user plane (UP) IP gateway for Inter RAT handover. It has the functions of a Mobile IP Home Agent (MIP HA). To all the other access networks, the Inter AS MM behaves like an external IP node. It is also possible that the UPE, GGSN and SAE anchor are co- .
located.
• The Policy and Charging Rules Function (PCRF) specifies the allowed quality-of-service (QoS) for the users as well as the charging policies for the users.
The reference points in Figure 1 are as follows
• The Gb reference point exists between the SGSN and the BSC of the GERAN. The lu reference point exists between the SGSN and the RNC of the UTRAN.
• The S1 reference point is between the Evolved RAN and the MME/UPE of the Evolved Packet Core.
• The S2 reference point is between the IP gateway of a Non-3GPP Access System and the Inter AS Anchor. According to TR 23.882, this reference point is similar to Wi+. Wi is the reference point between the packet data gateway (PDG) of a scenario 3 l-WLAN and an external PDN. Wi+ is the Wi reference point with mobility extensions, e.g., Mobile IP (MIP).
• The S3 reference point exists between the GPRS core and the SAE MME. This is a signaling reference point and is expected to be like the Gn reference point between the SGSN and GGSN in UMTS networks.
• The S4 reference point is a reference point for user plane packets and exists between the GPRS core and the Inter AS Anchor. The S4 reference point is like the Gn reference point between the SGSN and GGSN in UMTS networks.
• The S5 reference point is between the SAE/LTE UPE and the Inter AS Anchor. Depending on the architecture alternative, this reference point could be an internal reference point
• The S6 reference point is between the Evolved Packet Core and the HSS.
• The Rx+, interface is an enhancement of the Rx interface.
• The S7 reference point is between the evolved packet core and the PCRF. This reference point exists between the Inter AS Anchor and the PCRF. Depending on the functions at the SAE/LTE UPE, this reference point could also exist between the SAE UPE and PCRF.
• The SGi reference point is like an enhanced Gi reference point and exists between the Inter AS Anchor and the external packet data network (PDN)
The WiMAX access system architecture is as shown in Figure 2. The WiMAX system consists of an Access Service Network (ASN) and a Connectivity Service Network (CSN). The ASN consists of the Base Station (BS) and the ASN gateway. The CSN may consist of DHCP server, Mobile IP (MIP) Home Agent (HA), Authentication, Authorization and Accounting (AAA) server, etc. The CSN for WiMAX could be a new network on its own or could be an incumbent 3GPP or 3GPP2 core network. The WiMAX CSN could also contain an interworking unit that enables the interworking of WiMAX networks with incumbent networks like WLAN, 3GPP or 3GPP2 access networks.
The reference points in Figure 2 are as follows
• The R1 reference point is between the Mobile Subscriber Station (MSS) or Subscriber Station (SS) or User Equipment (UE) and the ASN. In and ASN multiple BS can be associated with an ASN gateway and vive-versa.
• The R2 reference point is a logical reference point between the UE and the CSN
• The R3 Reference point exists between the ASN and CSN. In WiMAX, multiple ASN can be associated with a CSN and vice-versa.
• The R4 reference point exists between ASN gateways. This reference point assists in context transfer and data transfer during mobility across ASN gateways
• The R5 reference point exists between CSN's. The R5 reference point is used during inter-CSN mobility. Also during roaming, the R5 reference point is used for authentication from Home CSN or for IP address assignment from home CSN
• The R6 reference point exists between the BS and the ASN gateway. This is used during call set up and during Intra- ASN gateway mobility (or L2 mobility or inter BS mobility)

• The R8 reference point exists between BS. This is used for control plane signaling and data transfer during inter BS mobility
• The ASN gateway can optionally have a separate control plane node (called decision point) and a user plane node (called enforcement point). In such cases an internal R7 reference point could exist between the decision and enforcement points.
The IEEE 802.21 Media Independent Handover (MIH) working group in the IEEE has defined an MIH function and a corresponding set of messages to enable handover between heterogeneous wireless access networks. The MIH function and its interaction with higher and lower layers are shown in Figure 3. The MIH reference model for different access systems like WLAN, WiMAX, 3GPP, 3GPP- LTE and 3GPP2 are available in IEEE P802.21/D00.05: Draft IEEE Standard for Local and Metropolitan Area Networks: Media Independent Handover Services, January 2006.
The MIH function consists of the Media Independent Event Services (MIES), the Media Independent Command Services (MICS) and Media Independent Information Services (MIIS). The MIES consists of events reported from lower layers to higher layers. MIES is classified into link events (from lower layers to the MIH function) and MIH events (events reported by MIH function to higher layers). MICS consists of commands from higher to lower layers. MICS is classified into Link Commands (from MIH function to lower layers) and MIH commands (from higher layers to MIH function). The MIIS is classified into general network information, link layer information and higher layer information. This is used to enable the Mobile user or the network to select the target network. Some examples of the functions of each of MIES, MICS and MIIS are as listed below
Media Independent Event Services (MIES)
Link events
• Link Detected, Link Parameter Change
• Link Going down (predictive event)
• Link Synchronous Events (e. g., precise HO timing) MIH events
• Handover prediction
• Handover Completion
Media Independent Command Services (MICS) Link commands
• Link event register, de-register, Link Capability Discover, Link Configure Threshold commands
MIH commands
• Scan, poll, HO prepare, HO initiate, HO Complete, HO Commit commands Media Independent Information Services (MIIS)
• General Network Information (Operator ID, Network ID, Location, RAT, charging information, roaming partners)
• Link Layer Information (Link status (measurements), QoS, rate set, channels available, security information (supported algorithms), neighbor information)
• Higher layer information (Support for MIP/SIP, Support for MMS, VoIP)
The MIIS also includes the Media Independent Neighbor Graph (MING), which is a collection of all neighbors to a given point of attachment and the reachability of one neighbor form the other.
LIMITATIONS
In the prior art, there is no efficient mechanism and messages specified to provide handover between the SAE/LTE system and other access systems in a generic way (i. e., using the IEEE 802.21 MIH function).

SUMMARY OF THE INVENTION
The primary object of the invention is to define a method to provide handover between the SAE/LTE and other access systems using IEEE 802.21 MIH function.
Another object of the invention is to define a generic method using IEEE 802.21 MIH function.
It is another object of the invention to optimize the network access authentication procedure and pre establishment of security association in the target access network during handover.
It is another object of the invention to include a new command called MICS: HO Response to indicate acceptance or rejection of the HO.
It is another object of the invention to include security related information in the higher layer information sent in MIIS.
It is another object of the invention to obtain policy ruled from PCRF prior to handover to enable policy enforcement in the target RAT.
It is another object of the information to enable UE initiated handover based on measurements.
It is another object of the invention to buffer the data destined to the UE during handover procedure, and forward the data to the UE after handover procedure to minimize data loss due to dropped packets.
It is another object of the invention that Handover preparation be performed to reserve radio and network resources for the UE before the handover is performed.
It is another object of the invention, to relay the RAN parameters of the target access system to the UE to enable optimized L2 attach procedures.
It is another object of the invention to illustrate the above objects.
The present invention provides a method for supporting mobility between the SAE/LTE access system and the UMTS, WiMAX and IWLAN access systems both when the UE does not have capability to access both systems simultaneously, as well as when the UE can access both systems simultaneously.
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 THE ACCOMPANYING DRAWINGS
Figure 1 illustrates the SAE/LTE System Architecture
Figure 2 illustrates the WiMAX architecture and reference points
Figure 3 illustrates the IEEE 802.21 Media Independent Function and its interactions with higher and lower layers.
Figure 4 illustrates SAE/LTE System architecture inter-worked with the WiMAX system with the Inter working unit (IWU).
Figure 5 illustrates the generic message flows/sequence for the handover between heterogeneous wireless access systems
Figure 6 illustrates the message flows/sequence for the handover from SAE/LTE Access System to UMTS access system using the IEEE 802.21 MIH function
Figure 7 illustrates the message flows/sequence for the handover from UMTS access system to the SAE/LTE Access System using the IEEE 802.21 MIH function
Figure 8 illustrates the message flows/sequence for the handover from SAE/LTE Access System to WiMAX access system using the IEEE 802.21 MIH function
Figure 9 illustrates the message flows/sequence for the handover from WiMAX access system to the SAE/LTE Access System using the IEEE 802.21 MIH function
Figure 10 illustrates the message flows/sequence for the handover from SAE/LTE Access System to IWLAN access system using the IEEE 802.21 MIH function
Figure 11 illustrates the message flows/sequence for the handover from IWLAN access system to the SAE/LTE Access System using the IEEE 802.21 MIH function
Figure 12 illustrates the message flows/sequence for the handover from SAE/LTE Access System to cdma2000 access system using the IEEE 802.21 MIH function
Figure 13 illustrates the message flows/sequence for the handover from cdma2000 access system to the SAE/LTE Access System using the IEEE 802.21 MIH function
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.
The operation of the invention is detailed below
Case 1: Generic approach for MIH based Handover when UE is not capable of simultaneous access
The present invention provides a generic procedure for handover between the heterogeneous wireless access systems. The architecture for inter-working of 3GPP access system with other access systems is shown in Figure 4. The IWU can convert the SAE/LTE protocols to WiMAX protocols and vice-versa. The IWU can communicate with the MME/UPE over the S12 interface and can communicate with the PCRF on the S7* interface. In this mechanism, the functions performed by the various network entities are as follows:
• The IWU can convert LTE RAN containers to WiMAX RAN containers and vice-versa. In effect, the IWU works as an MME/UPE for the SAE/LTE network and a WiMAX ASN gateway for the WiMAX network
• The IWU can obtain policy and charging rules from the PCRF and pass them to the ASN gateway during the preparation phase.
• The IWU could be
o a separate entity (or)
o co-located with MME/UPE (or)
o co-located with WiMAX ASN gateway (or)
o be located in a WiMAX CSN
An illustrative example of the handover procedure between heterogeneous
wireless access systems is depicted in Figure 5. In all the presented mechanisms, the IEEE 802.21 MIH function is divided into lower and upper MIH and is split into different entities in the network. Typically, the lower MIH resides in the Radio Network and upper MIH resides in the core network. The description of the handover procedure is provided below.
1. The UE performs a Link Event registration request message to the serving radio network. This includes registration for events like link going down.
2. The source radio network sends an MIH event registration request to the source Core network which includes predication of handovers. The prediction could be made on periodic measurements or on receiving possibility of link going down from the UE.
3. The source core network sends an Event registration confirm to the source radio network to enable reporting of MIH events
4. The source radio network responds to the link event registration request sent in Step 1.
5. This step has two possibilities
a. The UE could sense that the downlink is going down based on downlink measurements
b. The source radio network could sense that the uplink is going down based on uplink measurements
6. Depending on the downlink signal strength the UE could send a request to the source radio network to indicate the list of neighboring networks. This is done by sending the MING request
7. The Network responds with a MING response providing the neighbor

network information. This could include not only the network type but also radio type, radio parameters known, neighboring radio network capabilities etc. In case the network detected the event of link going down, then the source radio network can provide an unsolicited MING response to the UE.
8. The UE performs the neighboring RAT measurements. These measurements could include QoS along with signal strength. The QoS measured could be maximum bit rate supported for a given BER performance.
9. The UE sends an MIIS link layer information including the measured signal strength and QoS reports.
10. The source radio network forwards the link layer information to the source core network. This is to enable the source core network to obtain policies for the UE form the corresponding entity (e. g., PCRF) and rank the target RATs according to the measurements obtained from the UE.
11. The source core network ranks the target RATs according to signal strength, policies, pricing, etc. and chooses the target RAT. Alternatively, the UE could indicate choice of the target network in Step 9 by sending an MICS HO request instead of MIIS Link Layer information.
12. The source core network sends an MICS HO request to the target core network. The source core network also identifies the target core network ids based on the link layer information provided by the UE from the measurements made. The source core network sends an MIIS Higher layer information message to the target core network. This includes the QoS of the existing flows and other contexts related to the flows. In addition, this could include the capabilities of the UE like security capabilities, IP version supported, support for SIP, etc., Optionally this
message could also include security related information like security and/or mobility related keys, agreed security algorithms, etc. depending on the access networks. In case the protocols supported by the access networks does not allow transfer of keys at this step or the target access system is capable of AAA Infrastructure and has common AAA server for authentication, then identities like network access identifier (NAI) can be included to enable the target access network identify the AAA server and obtain the UE security/mobility keys from the AAA server.
13. The target core network sends an MICS HO prepares message to the target radio network and sends the QoS related information. Depending on the access network, if security is performed at radio network node, then this message could also include security related information.
14. The target radio network reserves the necessary resources for the UE.
15. The target Radio network sends an MICS HO Response message to the target core network.
16. The target radio network also sends an MIIS link layer information to the target core network. This could include parameters to optimize L2 attach procedures when the UE moves to the target access network. This could also include temporary IDs of the UE in the target radio network.
17. In case the target core network did not receive the security and/or mobility related information from the source core network in Step 12, then the target core network obtains the relevant security information from the AAA server.
18. The AAA server responds with the security and/or mobility related keys in case Step 17 was performed.

19. The target core network sends an MICS HO Response to the source core network. The target core network also sends an MIIS Higher layer information which could include link layer information as transparent containers. In this step, the IP address allocated to the UE in the target network. In this step, any information on downgraded QoS information at the target network is also included. Optionally, in this step, triggers for buffering UP packets to avoid loss of data, can be performed. This trigger could be to the Home agent or the buffering could take place at the source core network. Another option is that, the Home agent can bi- cast packets to the source and target access networks and buffering can be done at the target network. Optionally, in this step, to optimize the authentication procedure during handover, if target access system is capable of AAA infrastructure, then the AAA server can generate the temp identities for the UE and send along with this message.
20. The source core network forwards the information obtained in Step 19 to the source radio network
21. The source radio network provides the target network information to the UE.
22. The source radio network sends an MICS HO command to the UE indicating the time of HO and the target network
23. The UE performs radio network attachment procedures in an optimized manner from the parameters obtained in Step 21.
24. The target radio network indicates arrival of the UE to the target core network by sending an MIES HO complete message.
25. The UE can optionally perform network level attachment. This could be done by an MIP update. In case network based mobility procedures like
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PMIP or GTP or NeTLMM is used (depending on the target access network), then this step is performed by the target core network. In case means to adopt loss less handover were performed in Step 19, then the buffered packets are retrieved in this step. In case buffering performed at the target core network, then the buffered packets are forwarded to the UE through the target radio network.
26. The target core network sends an MICS HO complete message to the source core network.
27. The source core network and radio network release the resources reserved for the UE. Optionally, a timer can be included at the source access network and the radio and network resources in the source access network can be released after expiry of the timer.
28. Depending on the target access network location update procedures can be performed.
Case 2: Handover between SAE/LTE and UMTS access systems Handover from SAE/LTE to UMTS access systems
An illustrative example of the handover procedure from SAE/LTE access system to the UMTS access system in this mechanism is depicted in Figure 6. The source radio network is the evolved RAN and the target radio network is the RNC. The source core network consists of the MME and the combined UPE and GGSN. The target core network consists of SGSN and combined UPE and GGSN. It is also possible that the SAE/LTE Radio network consists of evolved RAN and UPE and the SAE/LTE core network consists of MME and the SAE Anchor. Henceforth, throughout the patent, whenever a mention of SAE/LTE network is made, both the above mentioned alternatives are possible even if only one of them is mentioned. The description of the handover procedure is provided below.
Steps 1-16 are as explained in Case 1. For this handover, the security related information is also transferred from the MME to the SGSN in Step 12.
Steps 17 and 18 mentioned in Case 1 are not performed.
Steps 17-26 in this HO procedure is same as the Steps 19-28 mentioned in Case 1, except that Step 25 in Case 1 corresponds to Step 23 for the SAE/LTE to UMTS HO and it is a network based user plane route update procedure, which is GTP based.
Handover from UMTS to SAE/LTE access systems
An illustrative example of the handover procedure from UMTS access system to the SAE/LTE access system in this mechanism is depicted in Figure 7. The source radio network is the RNC and the target radio network is the evolved RAN. The source core network consists of the SGSN and the combined UPE and GGSN. The target core network consists of MME and combined UPE and GGSN. The description of the handover procedure is provided below.
Steps 1-16 are as explained in Case 1. For this handover, the security related information is also transferred from the SGSN to the MME in Step 12.
Steps 17 and 18 mentioned in Case 1 are not performed.
Steps 17-26 in this HO procedure is same as the Steps 19-28 mentioned in Case 1, except that Step 25 in Case 1 corresponds to Step 22 for the UMTS to SAE/LTE HO and it is a network based user plane route update procedure, which is GTP based.
Case 3: Handover between SAE/LTE and WiMAX access systems Handover from the SAE/LTE to the WiMAX access system
An illustrative example of the handover procedure from SAE/LTE access system to the WiMAX access system in this mechanism is depicted in Figure 8. The source radio network is the evolved RAN and the target radio network is the WiMAX BS. The source core network consists of the MME and the combined UPE and GGSN. The target core network consists of ASN Gateway and the IWU. The description of the handover procedure is provided below.
Steps 1-16 are as described for Case 1. Alternatively, after step 12, the ASN gateway interacts with the AAA server as described in step 17 and 18, and then does the remaining steps. Then in step 13, the ASN gateway can send the keys required for security/mobility to the BS.
Step 17-18: AAA interactions mentioned in Figure 8 are same as the steps 17-18 mentioned in Case 1. Optionally, this can be carried out by interactions with the IWU. In other words, the ASN gateway can request the IWU to obtain the keys from the serving MME or from the AAA server. Alternatively, if the UE obtains temporary IDs from the target access system in the step 21 and the target access system request for authentication during radio network attach procedure, then temporary IDs for fast re-authentication can be used and this can be performed in after Step 24 (before Step 25).
Steps 19-27 are as mentioned in Case 1. The parameters for optimizing L2 attach procedure could be the ranging code, basic and primary CIDs or ranging frequency, etc. Step 25 could be a PMIP update in case the UE does not involve in HO signaling or could be an MIP update if UE is involved in HO signaling.
Step 28 is a location update procedure which can be done by sending a tracking area update to the IWU. This can be done by having a transparent container between the UE and the IWU or can be a WiMAX paging zone update which, in turn, could be translated by the IWU to be a tracking area update message and the HSS can be update accordingly.
Handover from the WiMAX to the SAE/LTE access system
An illustrative example of the handover procedure from WiMAX access system to the SAE/LTE access system in this scenario is depicted in Figure 9. The source radio network is the WiMAX BS and the target radio network is the evolved RAN. The source core network consists of the ASN Gateway and the IWU. The target core network consists of MME and the combined UPE and GGSN. The description of the handover procedure is provided below:
Steps 1-18 are as mentioned in Case 1. Steps17-18 is the AAA interactions mentioned in case 1. For the WIMAX to SAE/LTE HO, the MME can obtain the UE security context from the AAA server (which can be obtained using the NAI sent to the MME in Step 12) or the MME can obtain the context from the IWU. In case the MME needs to obtain the context from the IWU, then the IWU id should be included in step 12. Alternatively, if temporary IDs for fast re-authentication can be used then this can be performed in after Step 24 (before Step 25).
Steps 19-23 are as mentioned in Case 1. The parameters for optimizing L2 attach procedure could be the basic and primary CIDs or ranging frequency, etc.
Step 24 is the tunnel establishment with the UPE. In parallel, the MIES HO complete message can be sent to the MME. These two parallel messages can be combined in case the MME and UPE are co-located.
Step 25 could be a PMIP update in case the UE does not involve in HO signaling or could be an MIP update if UE is involved in HO signaling.
Case 4: Handover between SAE/LTE and Inter-working WLAN (IWLAN) access systems
Handover from the SAE/LTE to the IWLAN access system y
An illustrative example of the handover procedure from SAE/LTE access system to the IWLAN access system in this mechanism is depicted in Figure 10. The source radio network is the evolved RAN and the target radio network is the WLAN AP. The source core network consists of the MME and the combined UPE and GGSN. The target core network consists of ILWAN PDG or any other access gateway. The description of the handover procedure is provided below.
Steps 1-16 are as described for Case 1. Alternatively, after step 12, the PDG interact with the AAA server as described in step 17 and 18, and then does the remaining steps. Then in step 13, the PDG can send the keys required for security to the WLAN network.
Step 17-18: AAA interactions mentioned in Figure 10 are same as the steps 17- 18 mentioned in Case 1. Alternatively, the UE obtains temporary IDs from the target access system in the step 21 and the target access system request for authentication during radio network attach procedure, then temporary IDs for fast re-authentication can be used then this can be performed in after Step 24 (before Step 25).
Steps 19-27 are as mentioned in Case 1. The parameters for optimizing L2 attach procedure could be the ranging code, basic and primary CIDs or ranging frequency, etc. Step 25 could be a PMIP update in case the UE does not involve in HO signaling or could be an MIP update if UE is involved in HO signaling. Also Step 24 consists of two parallel steps-one being the MIES HO Complete and the other being IPSec establishment. In case there is no PDG and there exists another access gateway, then IPSec establishment is not necessary.
Handover from the IWLAN to the SAE/LTE access system
An illustrative example of the handover procedure from WiMAX access system to the SAE/LTE access system in this scenario is depicted in Figure 11. The source radio network is the WLAN AP and the target radio network is the evolved RAN. The source core network consists of the IWLAN PDF or any other access gateway. The target core network consists of MME and the combined UPE and GGSN. The description of the handover procedure is provided below:
Steps 1-18 are as mentioned in Case 1. Steps17-18 is the AAA interactions mentioned in case 1. For the IWLAN to SAE/LTE HO, the MME can obtain the UE security context from the AAA server (which can be obtained using the NAI sent to the MME in Step 12. Alternatively, if temporary IDs for fast re-authentication can be used then this can be performed in after Step 24 (before Step 25).
Steps 19-23 are as mentioned in Case 1. The parameters for optimizing L2 attach procedure could be the basic and primary CIDs or ranging frequency, etc.
Step 24 is the tunnel establishment with the UPE. In parallel, the MIES HO complete message can be sent to the MME. These two parallel messages can be combined in case the MME and UPE are co-located.
Step 25 could be a PMIP update in case the UE does not involve in HO signaling or could be an MIP update if UE is involved in HO signaling.
Case 5: Handover between SAE/LTE and cdma2000 access systems
Handover from the SAE/LTE to the cdma2000 access system
An illustrative example of the handover procedure from SAE/LTE access system to the cdma2000 access system in this mechanism is depicted in Figure 12. The source radio network is the evolved RAN and the target radio network is the CDMA2000 BSC and PCF (the BSC and PCF could be co-located or could be separate). The source core network consists of the MME and the combined UPE and GGSN. The target core network consists of the PDSN. The description of the handover procedure is provided below.
Steps 1-18 are as described for Case 1. Alternatively, if temporary IDs for fast re- authentication can be used then steps 17 and 18 can be performed after Step 24 (before Step 25).
Steps 19-27 are as mentioned in Case 1. Step 24 consists of two parallel steps- one being the MIES HO Complete and the other being PPP establishment. The MIES HO complete, in parallel, initiates A9 and A11 establishment for A8 and A10, respectively. Step 25 could be a PMIP update in case the UE does not involve in HO signaling or could be an MIP update if UE is involved in HO signaling.
Additionally, Step 28 location update procedure can be done by sending a location update to the MSC through the BSC. The MSC could, in turn, update the HSS.
Handover from the CDMA2000 to the SAE/LTE access system
An illustrative example of the handover procedure from WiMAX access system to the SAE/LTE access system in this scenario is depicted in Figure 13. The source radio network is the CDMA2000 BSC and PCF (the BSC and PCF could be co- located or could be separate) and the target radio network is the evolved RAN. The source core network consists of the PDSN. The target core network consists of MME and the combined UPE and GGSN. The description of the handover procedure is provided below:
Steps 1-18 are as mentioned in Case 1. Steps17-18 is the AAA interactions mentioned in case 1. For the CDMA2000 to SAE/LTE HO, the MME can obtain the UE security context from the AAA server (which can be obtained using the NAI sent to the MME in Step 12. Alternatively, if temporary IDs for fast re- authentication can be used then this can be performed in after Step 24 (before Step 25).
Steps 19-23 are as mentioned in Case 1. The parameters for optimizing L2 attach procedure could be the basic and primary CIDs or ranging frequency, etc.
Step 24 is the tunnel establishment with the UPE. In parallel, the MIES HO complete message can be sent to the MME. These two parallel messages can be combined in case the MME and UPE are co-located.
Step 25 could be a PMIP update in case the UE does not involve in HO signaling or could be an MIP update if UE is involved in HO signaling.
Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention.
GLOSSARY OF TERMS AND DEFINITIONS THEREOF
3GPP: 3rd Generation Partnership Project
3GPP2: 3rd Generation Partnership Project 2
AAA: Authentication, Authorization and Accounting
ASN: Access Service Network
APN: Access Point Name
AS: Access System
AV: Authentication Vector
AuC: Authentication Center
BTS. Base Transceiver Station
BS: Base Station
BSC: Base Station Controller
CDMA: Code Division Multiple Access
CSN: Connectivity Service Network
DHCP: Dynamic Host Configuration Protocol
ENB: Evolving Node B
FA: Foreign Agent
GERAN: GSN EDGE Radio Access Network consisting of the BTS and BSC GGSN: Gateway GPRS Support Node GPRS: Generalized Packet Radio Services
HA: Home Agent, a router on a mobile node's home network that tunnels packets to the mobile node while it is away from home. HLR: Home Location Register HO: Handover
HSS: Home Subscription Server
SAE Anchor: Inter Access System Mobility Manager, an entity assisting in mobility across access systems L2: Layer 2 L3: Layer 3
LTE: Long Term Evolution
MICS: Media Independent Command Services
MIES: Media Independent Event Services
MIH: Media Independent Handover: A working group in IEEE called IEEE 802.21
MIIS: Media Independent Information Services
MIP: Mobile Internet Protocol includes version 4 and version 6
MME: Mobility Management Entity
MSC: Mobile Switching Center
MSS: Mobile Subscriber Station
NAI: Network Address Identifier
NAP: Network Access Provider
Node B: The base station in a UMTS network
NSP: Network Service Provider
PCF: Packet Control Function
PCRF: Policy and Charging Rules Function
PDP: Packet Data Protocol
PDSN: Packet Data Serving Node
QoS: Quality of Service
RAT: Radio Access Technology
RRC: Radio Resource Control
SAE: System Architecture Evolution
SGSN: Serving GPRS Support Node
SS: Subscriber Station
UE: User Equipment
UPE: User Plane Entity
UMTS: Universal Mobile Telecommunication Systems
User terminal: The end user equipment e.g., the Mobile Station (MS) or User Equipment (UE).
UTRAN: UMTS Terrestrial Radio Access Network consisting of the Node B and the RNC.









We Claim,
1. A method to provide mobility for MIH based Handover when UE is not capable of simultaneous access comprising:
(1) the UE performing a Link Event registration request message to the serving radio network;
(2) a source radio network sending an MIH event registration request to the source Core network which includes predication of handovers;
(3) the source core network sending an Event registration confirm to the source radio network to enable reporting of MIH events;
(4) the source radio network responds to the link event registration request sent in Step 1;
(5) The UE sensing that the downlink is going down based on downlink measurements or the source radio network sensing that the uplink is going down based on uplink measurements;
(6) Depending on the downlink signal strength the UE sending a request to the source radio network to indicate the list of neighboring networks by sending the MING request;
(7) the Network responding with a MING response providing the neighbor network information and in case the network detecting the event of link going down, then the source radio network provide an unsolicited MING response to the UE;
(8) the UE performing neighboring RAT measurements where these measurements include QoS along with signal strength;
(9) the UE sending an MIIS link layer information including the measured signal strength and QoS reports;
(10) the source radio network forwarding the link layer information to the source core network;
(11) the source core network ranking the target RATs and choosing the target RAT and , the UE indicating choice of the target network in Step 9 by sending an MICS HO request instead of MIIS Link Layer information;
(12) the source core network sending an MICS HO request to the target core
network and the source core network identifying the target core network ids based on the link layer information provided by the UE from the measurements made and further comprising the steps of: the source core network sending an MIIS Higher layer information message to the target core network which includes the QoS of the existing flows and other contexts related to the flows; including the capabilities of the UE; Optionally including security related information depending on the access networks, wherein if the protocols supported by the access networks does not allow transfer of keys at this step or the target access system is capable of AAA Infrastructure and has common AAA server for authentication, then identities like network access identifier (NAI) can be included to enable the target access network identify the AAA server and obtain the UE security/mobility keys from the AAA server;
(13) the target core network sending an MICS HO prepare message to the target radio network and sending the QoS related information wherein depending on the access network, if security is performed at radio network node, then this message including security related information;
(14) the target radio network reserving the necessary resources for the UE;
(15) the target Radio network sending an MICS HO Response message to the target core network;
(16) the target radio network sending an MIIS link layer information to the target core network which include parameters to optimize L2 attach procedures when the UE moves to the target access network and further include temporary IDs of the UE in the target radio network;
(17) in case the target core network did not receive the security and/or mobility related information from the source core network in Step 12, then the target core network obtaining the relevant security information from the AAA server;
(18) the AAA server responding with the security and/or mobility related keys in case Step 17 was performed;
(19) the target core network sending an MICS HO Response to the source core network and also sending an MIIS Higher layer information which include link layer information as transparent containers and , the IP address allocated to the UE in the target network where , any information on downgraded QoS information at the target network is also included and further comprising the steps of optionally, triggering for buffering UP packets to avoid loss of data, where the trigger could be to the Home agent or the buffering taking place at the source core network; the Home agent bi-casting packets to the source and target access networks and buffering done at the target network; optionally, optimizing the authentication procedure during handover, and if target access system is capable of AAA infrastructure, then the AAA server generating the temp identities for the UE and sending along with this message;
(20) the source core network forwarding the information obtained in Step 19 to the source radio network;
(21) the source radio network providing the target network information to the UE;
(22) the source radio network sending an MICS HO command to the UE indicating the time of HO and the target network;
(23) the UE performing radio network attachment procedures in an optimized manner from the parameters obtained in Step 21;
(24) the target radio network indicating arrival of the UE to the target core network by sending an MIES HO complete message;
(25) the UE optionally performing network level attachment which is done by an MIP update and if network based mobility procedures is used then this step is performed by the target core network and if means to adopt loss less handover were performed in Step 19, then the buffered packets are retrieved in this step and in case buffering performed at the target core network, then the buffered packets are forwarded to the UE through the target radio network;
(26) the target core network sending an MICS HO complete message to the source core network;
(27) the source core network and radio network release the resources reserved for the UE and optionally, a timer is included at the source access
network and the radio and network resources in the source access network is released after expiry of the timer; and (28) performing update procedure depending on the target access network location.
2. A method according to claim 1 wherein the Handover from SAE/LTE to UMTS access systems comprising the steps of:
performing steps 1 to 16 where in for this handover, the security related information is transferred from the MME to the SGSN in Step 12; and
performing steps 19-28 mentioned in Claim 1, except that Step 25 of claim 1 corresponds to the SAE/LTE to UMTS HO and a network based user plane route update procedure, which is GTP based.
3. A method according to claim 1 wherein the Handover from UMTS to SAE/LTE access systems comprising the steps of:
performing Steps 1-16 are as explained in Claim 1 where the security related information is also transferred from the SGSN to the MME in Step 12.
performing steps 19-28 in this HO procedure mentioned in claim 1, except that Step 25 in Claim 1 corresponds for the UMTS to SAE/LTE HO and is a network based user plane route update procedure, which is GTP based.
4. A method according to claim 1 wherein the Handover from the SAE/LTE to the WiMAX access system comprising the steps of:
Performing steps 1-16 as described in Claim 1 and alternatively after step 12, the ASN gateway interacts with the AAA server as described in step 17 and 18, and then doing the remaining steps; performing step 13, the ASN gateway sending the keys required for security/mobility to the BS;
Performing step 17-18 and optionally, carried out by interactions with the IWU, where the ASN gateway requesting the IWU to obtain the keys from the serving MME or from the AAA server and alternatively, if the UE obtains temporary IDs from the target access system in the step 21 and the target access system request for authentication during radio network attach procedure, then temporary IDs for fast re-authentication can be used and this performing after Step 24 (before Step 25);
Performing Steps 19-27 are as mentioned in Claim 1, the parameters for optimizing L2 attach procedure being the ranging code, basic and primary CIDs or ranging frequency, etc. and Step 25 being a PMIP update in case the UE does not involve in HO signaling or could be an MIP update if UE is involved in HO signaling; and
Performing step 28 which is a location update procedure which is done by sending a tracking area update to the IWU which is done by having a transparent container between the UE and the IWU or can be a WiMAX paging zone update which, in turn, could be translated by the IWU to be a tracking area update message and the HSS can be update accordingly.
5. A method according to claim 1 wherein the Handover from the WiMAX to the SAE/LTE access system comprising the steps of:
Performing steps 1-18 as mentioned in Claim 1, where Steps17-18 is the AAA interactions mentioned in claim 1, wherein for the WIMAX to SAE/LTE HO, the MME can obtain the UE security context from the AAA server (which can be obtained using the NAI sent to the MME in Step 12) or the MME can obtain the context from the IWU and in case the MME needs to obtain the context from the IWU, then the IWU id is included in step 12 and alternatively, if temporary IDs for fast re-authentication is used then this is performed in after Step 24 (before Step 25);
performing steps 19-23 as mentioned in claim 1, wherein the parameters for optimizing L2 attach procedure is the basic and primary CIDs or ranging frequency;
performing Step 24 which is the tunnel establishment with the UPE and in parallel, the MIES HO complete message can be sent to the MME where these two parallel messages can be combined in case the MME and UPE are co-located; and
performing step 25 which is a PMIP update in case the UE does not involve in HO signaling or is an MIP update if UE is involved in HO signaling.
6. A method according to claim 1 wherein Handover from the SAE/LTE to the IWLAN access system comprising the steps of:
performing steps 1-16 as described in claim 1 and alternatively, after step 12, the PDG interact with the AAA server as described in step 17 and 18, and then does the remaining steps wherein step 13, the PDG sends the keys required for security to the WLAN network;
performing step 17 -18and alternatively, the UE obtains temporary IDs from the target access system in the step 21 and the target access system request for authentication during radio network attach procedure, then temporary IDs for fast re-authentication is used then this is performed in after Step 24 (before Step 25); and
performing steps 19-27 as mentioned in claim 1 wherein the parameters for optimizing L2 attach procedure could be the ranging code, basic and primary CIDs or ranging frequency, etc. wherein Step 25 is a PMIP update in case the UE does not involve in HO signaling or is an MIP update if UE is involved in HO signaling and Step 24 consists of two parallel steps-one being the MIES HO Complete and the other being IPSec establishment and if there is no PDG and there exists another access gateway, then IPSec establishment is not necessary.
7. A method according to claim 1 wherein Handover from the IWLAN to the SAE/LTE access system comprising the steps of :
performing Steps 1-18 as mentioned in Claim 1 wherein Steps17-18 is the AAA interactions mentioned in claim 1 where for the IWLAN to SAE/LTE HO, the MME obtain the UE security context from the AAA server (which can be obtained using the NAI sent to the MME in Step 12 and alternatively, if temporary IDs for fast re-authentication is used then this can be performed in after Step 24 (before Step 25);
performing Steps 19-23 as mentioned in Claim 1 wherein the parameters for optimizing L2 attach procedure could be the basic and primary CIDs or ranging frequency;
performing Step 24 is the tunnel establishment with the UPE and in parallel, the MIES HO complete message can be sent to the MME. Where these two parallel messages can be combined in case the MME and UPE are co-located; and
performing Step 25 which is a PMIP update in case the UE does not involve in HO signaling or is an MIP update if UE is involved in HO signaling.
8. A method according to claim 1 wherein Handover from the SAE/LTE to the cdma2000 access system comprising the steps of:
performing steps 1-18 as described for Claiml and alternatively, if temporary IDs for fast re-authentication are used then steps 17 and 18 is performed after Step 24 (before Step 25);
performing Steps 19-27 as mentioned in Claim 1 and Step 24 consists of two parallel steps-one being the MIES HO Complete and the other being PPP establishment where step 25 is a PMIP update in case the UE does not involve in HO signaling or is an MIP update if UE is involved in HO signaling; and
additionally, performing Step 28 location update procedure done by sending a location update to the MSC through the BSC where the MSC could, in turn, update the HSS.
9. A method according to claim 1 wherein Handover from the CDMA2000 to the SAE/LTE access system comprising the steps of:
performing steps 1-18 as mentioned in Claim 1 where Steps17-18 is the AAA interactions mentioned in claim 1 wherein for the CDMA2000 to SAE/LTE HO, the MME can obtain the UE security context from the AAA server (which can be obtained using the NAI sent to the MME in Step 12 and alternatively, if temporary IDs for fast re-authentication can be used then this can be performed in after Step 24 (before Step 25);
performing Steps 19-23 are as mentioned in Claim 1 and the parameters for optimizing L2 attach procedure could be the basic and primary CIDs or ranging frequency;
performing Step 24 which is the tunnel establishment with the UPE where in parallel, the MIES HO complete message can be sent to the MME and these two parallel messages can be combined in case the MME and UPE
are co-located; and
performing step 25 which could be a PMIP update in case the UE does not involve in HO signaling or could be an MIP update if UE is involved in HO signaling.
10. A method to provide mobility substantially described particularly with reference to the accompanying drawings.

Documents:

2333-CHE-2006 CORRESPONDENCE OTHERS 12-06-2013.pdf

2333-CHE-2006 AMENDED CLAIMS 05-08-2013.pdf

2333-CHE-2006 CORRESPONDENCE OTHERS 12-06-2013.pdf

2333-CHE-2006 EXAMINATION REPORT REPLY RECEIVED 05-08-2013.pdf

2333-CHE-2006 FORM-1 05-08-2013.pdf

2333-CHE-2006 FORM-1 12-06-2013.pdf

2333-CHE-2006 POWER OF ATTORNEY 05-08-2013.pdf

2333-CHE-2006 POWER OF ATTORNEY 12-06-2013.pdf

2333-che-2006 abstract 17-12-2007.pdf

2333-CHE-2006 AMENDED PAGES OF SPECIFICATION 11-04-2013.pdf

2333-CHE-2006 AMENDED CLAIMS 11-04-2013.pdf

2333-che-2006 claims 17-12-2007.pdf

2333-che-2006 correspondence others 17-12-2007.pdf

2333-che-2006 description (complete) 17-12-2007.pdf

2333-che-2006 drawings 17-12-2007.pdf

2333-CHE-2006 EXAMINATION REPORT REPLY RECEIVED. 11-04-2013.pdf

2333-CHE-2006 FORM-1 11-04-2013.pdf

2333-CHE-2006 FORM-1 12-06-2013.pdf

2333-CHE-2006 FORM-13 11-04-2013.pdf

2333-che-2006 form-18.pdf

2333-che-2006 form-5 17-12-2007.pdf

2333-CHE-2006 OTHER PATENT DOCUMENT 11-04-2013.pdf

2333-CHE-2006 POWER OF ATTORNEY 11-04-2013.pdf

2333-CHE-2006 POWEROF ATTORNEY 12-06-2013.pdf

2333-che-2006-correspondnece-others.pdf

2333-che-2006-description (provisional).pdf

2333-che-2006-drawings.pdf

2333-che-2006-form 1.pdf

2333-che-2006-form 26.pdf


Patent Number 257242
Indian Patent Application Number 2333/CHE/2006
PG Journal Number 38/2013
Publication Date 20-Sep-2013
Grant Date 17-Sep-2013
Date of Filing 15-Dec-2006
Name of Patentee SAMSUNG INDIA SOFTWARE OPERATIONS PRIVATE LIMITED
Applicant Address BAGMANE LAKE VIEW BLOCK, 'B' NO 66/1, BAGMANE TECH PARK, C V RAMAN NAGAR, BYRASANDRA, BANGALORE -560093 KARNATAKA
Inventors:
# Inventor's Name Inventor's Address
1 SUNGHO CHOI EMPLOYED AT SAMSUNG ELECTRONICS CO.LTD ., GLOBAL STANDARD & RESEARCH LAB, TELE COMMUNICATION R&D CENTRE, TELE COMMUNICATION NETWORK, HAVING ITS OFFICE AT, 416 MEATAN-3DONG YEONGTONG-GU SUWON, KOREA-442-600
2 ANAND SANTHANA KRISHNAN 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 RAJAVELSAMY RAJADURAI 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
4 OSOK SONG EMPLOYED AT SAMSUNG ELECTRONICS CO.LTD ., GLOBAL STANDARD & RESEARCH LAB, TELE COMMUNICATION R&D CENTRE, TELE COMMUNICATION NETWORK, HAVING ITS OFFICE AT 416, MEATAN 3DONG YEONGTONG-GU SUWON, KOREA-442-600
PCT International Classification Number H04Q7/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA