WO2010086014A1 - Method and device for data processing in an access point supporting local breakout - Google Patents

Abstract

A method and a device for data processing in an access point are provided, wherein said access point provides a mobility management function for session management via at least one bearer; and wherein said access point communicates with at least one mobile terminal.

Description

Description

METHOD AND DEVICE FOR DATA PROCESSING IN AN ACCESS POINT SUPPORTING LOCAL BREAKOUT

The invention relates to a method and to a device for data processing in an access point

New cellular access technologies like LTE are capable of substituting home or enterprise wireless access systems that nowadays are, e.g., based on WLAN.

Upcoming standards like IMT advanced (IMT-A) are targeting the local access. 3GPP ReI.8 defines enhancements to reduce signaling for users that attach to HeNBs via a so-called closed subscriber group concept in order to perform access control already at the mobile nodes (UE) .

In case of massive deployment of HeNBs, the number of NBs in a mobile network will drastically increase. In case a local breakout (LBO) concept is applied, a serving gateway (S-GW) functionality and a packet data network gateway (P-GW) functionality are collocated with the HeNB (in the hAP) and the total number of gateways drastically increases. This may result in an increased signaling traffic as well as additional network management performance needs.

The problem to be solved is to overcome the disadvantages as mentioned above and in particular to provide an efficient solution for local bearer management for home base stations or home access points.

This problem is solved according to the features of the independent claims. Further embodiments result from the depending claims.

In order to overcome this problem, a method for data processing in an access point is provided - wherein said access point provides a mobility management functionality for session management via at least one bearer,

- wherein said access point provides said session management for at least one mobile terminal;

- wherein said access point provides means for controlling of at least one local breakout bearer.

In particular, said access point may communicate with the mobile terminal via a base station that is part of the access point and/or associated with said access point.

Said local breakout bearer (LBB) may in particular together with a standard bearer (no LBB) be utilized for the access point to access the network, in particular the mobile network (also referred to as MNO network) .

Said session management may relate to the communication with the at least one mobile terminal. In other words, the access point may provide the mobility management functionality for session management with at least one mobile terminal via at least one bearer.

It is noted that session management refers to any activity regarding a process of keeping track, maintaining, handling of a communication of the at least one mobile terminal in particular with the purposes of IP connectivity. Also, the term session management can refer to a portion of such communication and/or to a modification of its characteristic, e.g., a quality of service.

Local breakout (LBO) indicates that the mobile terminal may be handled by said access point to get IP connectivity instead of the operator networks' IP gateways (S-GW or PDN- GW. Hence, the base station of the access point provides the wireless interface and the access point may be connected via a fixed line to a mobile network conveying signaling traffic. However, data traffic from and to the mobile terminal may "break out" already at a home access point and not be tunneled to the operator's network. The UE can access the home network of the home access point (hAP) directly via this hAP . Also, the Internet may be accessed by the UE via the hAP ' s fixed line to the Internet (e.g., via a DSL line) .

Hence, it is suggested using LBO to reduce user traffic and using a separate local mobility and/or session management function to reduce signaling traffic in the operator's network.

It is further noted that mobile terminal may refer to any terminal comprising a wireless interface, in particular to a mobile phone, a personal digital assistant (PDA) , a computer with a mobile interface, etc. The mobile terminal may also be referred to as user equipment (UE) . The mobile terminal may request and/or utilize several bearers with different IP addresses .

Examples provided in the context of the current solution may use terms of LTE/SAE of 3GPP. However, the concept also applies to other access systems, e.g., to 3G UMTS. The basic LTE/SAE architecture is described in, e.g., 3GPP TS 23.401.

The approach provided herein advantageously may decide based on the mobile terminal's location (associated with said access point or not) and based on operator policies whether or not to allow for LBO.

It is of advantage to delegate management and/or control of (parallel) LBO bearers (e.g., session management of the LBB) from an external mobility management entity to the mobility management entity of the access point.

In an embodiment, said access point comprises a packet core gateway functionality. In a further embodiment, said access point accesses a network, in particular a mobile network, via a fixed line.

Hence, the LBB as well as a standard bearer may be utilized by said access point to communicate with an access point's local area network, the Internet or the mobile network, in particular with an MNO network. In particular, a standard bearer can be used to access the MNO network.

In a next embodiment, an external mobility management function provides context data of the mobile terminal to the access point's mobility management function.

It is also an embodiment that said context data comprises subscription data and/or security data relating to the mobile terminal .

Such context data may in particular be conveyed to the access point's mobility management function (also referred to as "local" mobility management (function or functionality)) during an attach procedure or during a handover procedure.

Said subscription data may comprise in particular

- a list of APNs for which local breakout (LBO) is allowed and/or

- security parameter for NAS message handling between the UE and the hAP, and/or additional MME control and/or management data, e.g.,

- a maximum APN restriction data and/or - Bearer IDs to be used by the hAP.

It is noted that the term mobility management function is also referred to as mobility management functionality or as mobility management. The mobility management may comprise at least one function or functionality referred to by such terminology. In addition, the mobility management may be distributed among the access point (referred to as local mobility management) and the network (e.g., a MNO network, wherein it is referred to as external mobility management) . The mobility management could in particular be or be associated with a mobility management entity (MME) .

Pursuant to another embodiment, the external mobility management function delegates at least one function to the mobility management function of the access point.

According to an embodiment, the at least one function comprises the functionality for session management of at least one bearer.

Hence, the mobility management of the access point may unload controlling the bearer establishment, modifications, etc., as well as it may unload signaling related to such proceedings from the external mobility management.

Advantageously, the access point may perform control tasks like authentication of LBO without any need for an own HSS interface. Also, no access to an operator's HSS database from a remote location is required.

According to another embodiment, the access point provides a proxy MME function to coordinate processing between the external mobility management function and the mobility management function of the access point.

Such proxy MME function may in particular distribute session management messages from the mobile terminal between the mobility management of the access point and the external mobility management, e.g., according to a type of bearer (i.e. LBB or non-LBB) , and it may provide a security context to the mobility management of the access point and/or synchronize the security context between the mobility management of the access point and the external mobility management . In yet another embodiment, the proxy MME function obtains a PDN connectivity request from the mobile terminal providing an access point name; and the proxy MME function checks whether a local breakout is admissible for said access point name and in the affirmative, the PDN connectivity request is forwarded to the mobility management function of the access point .

In case the access point name indicates that LBO is not admissible, the PDN connectivity request is forwarded to the external mobility management function. In case no access point name is indicated, a default APN can be assumed.

According to a next embodiment, the proxy MME function forwards an NAS message received to the external mobility management function in case it is no PDN connectivity request or in case it does not belong to a local breakout bearer.

Pursuant to yet an embodiment, a security status between the mobility management function of the access point and the external mobility management function is synchronized.

For example, the local MME (e.g., the mobility management function of the access point) may store the last NAS Count/Sequence number and convey changes thereof to the external MME (external mobility management function) .

According to another embodiment, the mobility management function of the access point controls a gateway functionality of the access point.

Said gateway functionality may comprise a S-GW functionality and/or a P-GW functionality.

The problem stated above is also solved by a device comprising a and/or being associated with a processor unit and/or a hard-wired circuit and/or a logic device that is arranged such that the method as described herein is executable thereon.

According to an embodiment, the device is a communication device, in particular a or being associated with an access point, in particular a home access point.

The access point provided may comprise a base station (HeNB) , an S-GW function, a P-GW function and said mobility management function. Said access point may communicated with a mobile network via a fixed line connection, e.g., via digital subscriber line, and may provide normal bearers and/or breakout bearers via said fixed connection.

The problem stated supra is further solved by a communication system comprising the device as described herein.

Embodiments of the invention are shown and illustrated in the following figures:

Fig.l shows a block diagram comprising a home access point (hAP) in combination with a fixed network and a MNO NW;

Fig.2 shows an "Attach Procedure" based on figure 5.3.2.1-1 of document 3GPP TS 23.401 (V8.4.1) supplemented by a step 17 that provides adding subscription data for the local MME in case LBO is allowed;

Fig.3 shows an "Sl-based handover" based on figure

5.5.1.2.2-1 of document 3GPP TS 23.401 (V8.4.1), wherein a step 5 is provided adding UE context data for LBO (as a first alternative) and a step 18b is provided indicating said described re-authentication and security comprising adding UE context data for

LBO (as a second alternative) . This approach may be associated with a home base station (or home NB, also referred to as HeNB) or any home access point (hAP) comprising a packet core gateway functionality, wherein said HeNB and/or hAP is preferably deployed at a customer's premises.

The HeNB and/or the hAP (referred to also as HeNB/hAP) may comprise means for controlling at least one local breakout bearer (LBB) .

Advantageously, this approach enables parallel and - if possible - independent access to an operator' s services and/or the operator's gateways (non-LBB) as well as to a local home network via local breakout bearers (LBB) .

A 3GPP concept of parallel PDN connectivity can be utilized, which allows a user equipment (UE) to request multiple default bearers with different IP addresses.

Hence, a mobile management entity (MME) may enable the hAP to handle the LBB locally. It may provide UE context data (comprising, e.g., subscription data and/or security data) of the user to the hAP during an attach procedure (wherein the UE is attached to the HeNB of the hAP) or during a handover (HO) procedure to this HeNB.

The MME may advantageously delegate some of its functionality to the hAP, in particular such that is related to a session management of local bearers.

UE context data provided may include security context to allow the hAP un-ciphering UE messages and intercepting session management messages like "PDN connectivity requests" from the UE. IMSI/S-TMSI information allows the hAP to page the UE. Furthermore, a number of Bearer IDs that have been reserved by the MME for the local access bearers can be used by the hAP. The MME may provide a list of access point names (APNs) for which LBO is allowed for a particular user (or UE) .

Hence, the hAP may comprise said HeNB as well as subsets of the MME, of the S-GW and/or of the P-GW functionality.

This allows to unload controlling the bearer establishment, modifications, etc., as well as to unload signaling related to such proceedings from the external MME towards the local MME of the hAP.

In addition, the MME may utilize one S-GW per UE for the purpose of handling this UE ' s sessions. Such S-GW can be regarded an anchor point for mobility in 3GPP systems. Furthermore, for such S-GW, only non-LBB can be maintained.

The solution provided allows the hAP performing control tasks like authentication of LBO without a need of an own HSS interface. Hence, advantageously, access to an operator's HSS database from any remote location can be avoided.

Preferably, as an option, an LBB handover to macro cells may not have to be supported. This may require service interruptions, which may be acceptable to some services, in particular such services with lower rates when associated UEs are connected via the HeNB and/or via fixed access.

It is also an advantage of the solution presented that only minor changes to ReI.8 MME as an external MME are required. Additional functionality is largely deployed with the hAP (HeNB, local MME, local S-GW and/or local P-GW functionalities) .

Another advantage of this approach is based on the fact that handling of bearers without local breakout does not have to be changed and can be supported in parallel to the LBB concept suggested. For such purpose, the HeNB/hAP may be enhanced with a local MME, S-GW and/or P-GW functionality and/or with a proxy MME.

Such proxy MME may coordinate processing between the external MME and the local MME. It may be arranged to distribute session management messages from the UE between the local MME and the external MME according to the type of bearer (i.e. LBB or non-LBB) and it may provide a security context to the local MME and synchronize the security context between the local MME and the external MME.

To keep the security status synchronized between the local MME and the external MME, the following concept may apply considering in particular an NAS count and a sequence number:

a) The local MME may maintain a current NAS count. For this purpose, the proxy MME may provide the latest downlink NAS sequence number used by the external MME, which will be increased by the local MME for its own messages.

b) The proxy MME may then inform the external MME about locally raised sequence numbers by including an additional message and/or an additional information element in at least one NAS message conveyed to the external MME.

This mechanism efficiently avoids that the local MME and the external MME use identical sequence numbers, which would lead to the UE rejecting NAS messages being interpreted as replay attacks.

c) In case the UE enters the home cell via handover instead of the attach process the following scheme may apply: After the HO, the MME may initiate a re-authentication and a security mode command procedure to reset the NAS count in the UE and the network. Hence, also an NAS count overflow counter is reset (to zero) and may be guessed by the hAP as well as by the UE. This may be required as not the total NAS count is transferred in the NAS messages, but only the Sequence number (as part of the NAS count) .

Fig.l shows a block diagram comprising a home access point (hAP) in combination with a fixed network and a MNO NW.

Fig.l shows a home access point hAP comprising a home NodeB HeNB, a local MME with an MME proxy function, a security tunnel function, a S-GW function and a P-GW function.

The home access point hAP is connected via a DSL Router or Modem with the Internet, which is further connected to a MNO network, which comprises a combined S-GW/P-GW with a security gateway SEC GW, a MME (also referred to as "external" MME) and a home subscriber server HSS.

It is noted that the combination of S-GW/P-GW and the security gateway SEC GW is one example and these components may as well be deployed and/or implemented separately from one another.

The home subscriber server HSS communicates signaling traffic with the MME of the MNO NW, which is provides an Sl interface with the local MME / MME proxy function of the home access point hAP. The MME of the MNO NW provides an SIl interface regarding signaling traffic towards the entity combining the S-GW, the P-GW and the SEC GW. The SEC GW conveys a standard bearer via the Internet and the DSL Router or Modem to the security tunnel function of the home access point hAP.

At least one local breakout bearer (LBB) is conveyed via the Internet and the DSL Router or Modem to the local S-/P-GW function of the home access point hAP or from the LAN of the home access point hAP to the local S-GW/P-GW function of the home access point hAP. Both, the security tunnel function and the local S-/P-GW of the home access point hAP are connected to the home NodeB HeNB, wherein the S-/P-GW has a signaling interface SIl* with the local MME. Furthermore, the home NodeB HeNB has a signaling interface Sl* with the local MME.

The home NodeB HeNB of the home access point hAP communicates user IP traffic as well as signaling traffic with a mobile terminal UE.

It is noted that the signaling links in Fig.l depict logical interfaces. Hence, the interfaces Sl, SIl may as well use the security tunnel between the home access point hAP and the MNO NW.

It is further noted that the interfaces Sl* and SIl* of the home access point hAP may deviate from the interfaces Sl and SIl in order to utilize the combined implementation in the home access point hAP for optimization purposes.

It is also noted that the term hAP may refer to or comprise the HeNB or vice versa. As shown in Fig.l, the hAP may be associated with the HeNB, it may in particular be a functional entity within the HeNB.

Exemplary Implementation, further Advantages:

In order to achieve an independence of LBO handling as well as operator GW-anchored services and/or bearers, the UE may have at least one default bearer that is not locally terminated, but terminated in the operator PDN-GW. No special handling is required for that purpose, e.g., mobility as defined in 3GPP TS 23.401 can be supported like handover between home cell and macro cell.

If the UE attaches to the HeNB or if the UE is handed over to the home cell, the external MME will check

- whether the UE is located in the home cell and/or - whether the UE is allowed to establish local beak-out bearers (LBB) .

In the affirmative, the external MME may add to (at least one of) the subsequent messages over the Sl interface towards the HeNB a data container with all relevant information that allows the hAP acting on behalf of the external MME to control the local bearers.

This data may comprise subscription data, e.g.,

- a list of APNs for which LBO is allowed and/or

- security parameter for NAS message handling between the UE and the hAP, and/or additional MME control and/or management data, e.g., - a maximum APN restriction data and/or

- Bearer IDs to be used by the hAP.

It may depend on UE ' s activity and/or policy to establish additional PDN connections when camping at the home cell, e.g., to request for a new PDN connection to the default APN.

Such requests can be analyzed in the hAP by the proxy MME function and may be routed differently: They may be directed either to the local MME or to the external MME. For processing purposes, the proxy MME function as well as the internal MME function may use the security context received from the external MME.

Functionalities of the hAP

Proxy MME functionality:

(1) Routing of session management messages:

- The HeNB may direct all Sl messages to the local proxy MME functionality.

- The proxy MME functionality checks whether the Sl message is a PDN connectivity request: - In the affirmative, the proxy MME checks if for this APN LBO is allowed:

- In the affirmative (i.e. in case APN LBO is allowed) the message is forwarded to the local MME. It is noted that the APN can be a part of the PDN connectivity request message, e.g., contained within protocol configuration options (PCO) . A procedure for ciphered APN may be optionally supported for LBO purposes. - If APN LBO is not allowed, the message is forwarded to the external MME.

- For other NAS messages (than the PDN connectivity request) , the proxy MME functionality may check if the session management message belongs to a LBB using a "Bearer ID" and a "Linked Bearer ID indicator":

- In the affirmative, the session management message is forwarded to the local MME, other, e.g., mobility management related messages, can be forwarded to the external MME. - If the session management message does not belong to a LBB, the NAS message is forwarded to the external MME.

(2) Sl related connection: In order to maintain the Sl connection to the HeNB, the external MME may transfer protocol related data (e.g., a "eNB UE Sl AP-ID") to the local MME to enable the local MME setting up messages to be conveyed towards the HeNB. As an option, the local MME does not have to use the existing Sl connection between the external MME and the HeNB to convey NAS messages to the HeNB and/or to the UE or the local MME may not have to establish a Sl signaling connection to the HeNB for starting the paging procedure .

(3) Synchronization of the security status between the local MME and the external MME: - An external MME NAS Count/Sequence number can be provided to the local MME.

- The local MME may store the last NAS Count/Sequence number, which can be used to convey messages from the local MME towards the UE.

- If the NAS count is locally increased, the local MME may send a synchronization message to the external MME to update its downlink NAS count. This can be done by a new message to be conveyed or it may be added to a message sent towards the external MME (e.g., from the UE), e.g., via a new information element .

- This efficiently avoids that the UE receives network messages with same NAS Counts/Sequence numbers, which would be erroneously interpreted by the UE as a replay attack.

- Optionally, for each UE NAS message directed to the local MME, a NAS synch message could be provided towards the external MME to update its uplink NAS Count.

(4) The proxy MME may maintain a local bearer ID table for session management message distribution purposes.

(5) The proxy MME may double certain Sl messages to be conveyed to the external MME and to the internal MME (e.g., an Sl release request or an Sl service request) to keep the local MME informed about the UE idle and/or active status.

(6) As an additional functionality, the local MME can be provided with an information related to a Mobility Management thereby enabling the local MME to perform the paging. E.g., a NAS message Information Elements like IMSI/S-TMSI of the UE can be utilized for such purpose. Local MME functionality:

(1) The local MME may controls the internal GW functionality of the hAP.

(2) Regarding a bearer setup messages to the HeNB (sent, e.g., via the Sl interface) the LBB may be marked, e.g., in order to exclude such bearer from handover handling by the HeNB.

(3) The local MME may check for a maximum or a level of APN restrictions, e.g., to avoid LBB connections in parallel to non-LBO connections to certain networks and/or APNs.

(4) As an additional functionality, the local MME may perform UE paging if triggered by the local S-GW functionality.

External MME functionality:

(1) The external MME may evaluate whether LBO is allowed:

- The external MME checks whether the UE is located in a home cell based on tracking area information, Cell ID and/or eNB IP address information. - For such purpose, the external MME may have access to related information, e.g., a Cell ID table and/or reserved ranges within the Cell-IDs. Alternatively or in addition, the external MME may use a S-GW selection function with DNS query deployed in particular with the home cell and/or a TAI: Depending on the APN, the DNS may return an indicator for LBB or it may reserve a special IP address of the S-GW (e.g., for IPv4 "127.0.0.1") to indicate (e.g., as a default) that for this APN LBO is allowed. - In this scenario, the DNS database may contains information whether it is a home cell and if LBO is allowed for that APN. (2) In particular due to operator policies, the external MME may decide if LBO is allowed for a particular APN.

- The external MME may apply operator policies for APNs (e.g., the Internet) to allow LBO or not. Such criterion could be taken into account in particular with further criteria like, e.g., a requirement for legal interception.

- Due to certain conditions or circumstances, the LBO allowance may be overruled and the external MME may assign a mobile network operator (MNO) GW address.

- The external MME may check if LBO is allowed for a particular user. Such inspection can be conducted based on subscription data stored at a home subscriber server (HSS) . For this purposes, the subscription data at the HSS can be enhanced and/or the maximum APN restriction feature can be used to decide whether LBO is allowed in parallel to another MNO bearer for further bearers to be established by a particular UE to be set up via the operator's S-GW and P-GW (for UE requested PDN connectivity procedure) .

- If LBO applies, the external MME may attach relevant UE context data in the attach procedure or in the handover procedure to appropriate messages to activate the LBO functionality in the hAP and to deliver data required, e.g.: UE subscription data (IMSI, list of allowed APN for LBO), security data, mobility management data and session management data (S-TMSI, reserved Bearer ID values for LBB) .

(3) If the UE enters the home cell via handover, the external MME processes a re-authentication and security mode command procedure after the handover to synchronize the NAS Counts in the external MME and in the local MME. This procedure can also be used to transfer UE context data to the hAP as described above. (4) If the UE detaches from the home cell or if the UE is handed over to a macro cell, the Bearer IDs reserved for LBB will be released.

(5) The external MME may provide for a maximum APN parameter for the local MME. Hence, special enhancements could be provided in the external MME, e.g., for a "maximum APN restriction" feature, information may be stored in the P-GW of the MNO NW.

(6) The external MME may increase its downlink NAS Count when receiving security synchronization messages and/or information elements from the hAP or from the local MME.

(7) The external MME may ignore gaps in the order of uplink NAS Count/Sequence numbers provided from the UE, in particular during at least one LBB being active. Such gaps may exist in case UE NAS messages are handled by the local MME.

Local S-GW functionality:

(1) In an idle state, the S-GW may trigger paging towards the external MME if the local bearer becomes active (downlink data) .

(2) As an option, the local S-GW may trigger paging in the local MME, the UE ' s response (service request) can then be handled by the external MME as if the UE was triggered in the usual way.

Handover (HO) :

In case of HO processed from the home cell to the macro cell, the HO can be performed for bearers that are terminated in the operator's NW (non LBB) only. In case of eUTRAN internal HO, the HeNB may remove the LBBs from the list of bearers to be handed over (SAE Bearers To Be Setup List) and releases the bearer towards the UE. After the HO being executed, the external MME and/or the core NW is/are informed via a "Path Switch"-message . No action may be required as the LBBs are not part of the external MME UE context .

HO with MME control (Sl HO) : In case of an MME change or in case of a inter-RAT HO, the MME may not include LBBs in the "SAE Bearers To Be Setup List" as the LBBs are not part of the MME UE context. The HeNB may thus release the LBBs towards the UE and the LBBs contexts in the internal MME.

In case no valid bearer is left after the HO to establish a default bearer in the new cell, a Tracking Area Update (TAU) reject of the MME may force a UE re-attach and establish a default bearer, in particular according to standard error handling.

Call Flow for Attach to home cell

An "Attach Accept"-message may comprise UE context data, control data and/or a list of APNs allowed for LBO.

After the attach procedure of the UE, a PDN connectivity in the home cell (with a particular APN or with a default APN indicator) can be handled (e.g., only) by the hAP .

Fig.2 is based on figure 5.3.2.1-1, "Attach Procedure" of document 3GPP TS 23.401 (V8.4.1). In addition, a step 17 is provided adding subscription data for the local MME in case LBO is allowed. Handover from macro cell to home cell (without changing the S-GW)

An HO request message may comprise UE context data, control data and/or a list of APNs allowed for LBO.

After the HO being processed, a re-authentication is performed by the external MME. As an alternative, such messages can also be used to transfer the UE context data to the hAP.

After completion of the HO, the PDN connectivity procedure requested by the UE in home cell (with a particular APN or with a default APN indicator) will be handled (e.g., only) by the hAP.

Fig.3 is based on figure 5.5.1.2.2-1, "Sl-based handover" of document 3GPP TS 23.401 (V8.4.1). In addition, a step 5 is provided adding UE context data for LBO (as a first alternative) . Furthermore, a step 18b is provided indicating said described re-authentication and security comprising adding UE context data for LBO (as a second alternative) .

It is noted that the external MME may not have to be changed according to a particular use case (i.e. source MME equals target MME) . Also, the S-GW does not have to be changed. The bearer request messages to the S-GW and/or to the P-GW relate to a non-local breakout bearer already being established when the UE camped in the macro cell. List of Abbreviations:

3GPP 3rd Generation Partnership Project

APN Access Point Name BS Base Station (also referred to as eNB)

EIR Equipment Identity Register eNB evolved NB

GW Gateway hAP home Access Point HeNB Home eNB

HO Handover

HSS Home Subscriber Server

IMSI International Mobile Subscriber Identity

IMT Internet Mobile Communications IMT-A IMT Advanced

IP Internet Protocol

IP-CAN IP Connectivity Access NW

LBB Local Breakout Bearer

LBO Local Breakout LTE Long Term Evolution

MME Mobility Management Entity

MNO Mobile Network Operator

NAS Non-Access Stratum

NB NodeB NW Network

PCEF Policy and Charging Enforcement Function

PCO Policy Configurations Option

PCRF Policy and Charging Rules Function

PDN Packed Data NW P-GW PDN GW

RAN Radio Access NW

RAT Radio Access Technology

S-GW Serving GW

TAI Timing Advanced Index TAU Tracking Area Update

TMSI Temporary Mobile Subscriber Identity

UE User Equipment (mobile station)

UL UP link UP User Plane

WLAN Wireless Local Area Network

Claims

Claims :

1. A method for data processing in an access point,

- wherein said access point provides a mobility management function for session management via at least one bearer;

- wherein said access point provides said session management for at least one mobile terminal;

- wherein said access point provides means for controlling of at least one local breakout bearer.

2. The method according to any of the preceding claims, wherein said access point comprises a packet core gateway functionality.

3. The method according to any of the preceding claims, wherein said access point accesses a network, in particular a mobile network and/or the Internet, via a fixed line.

4. The method according to any of the preceding claims, wherein an external mobility management function provides context data of the mobile terminal to the access point's mobility management function.

5. The method according to claim 4, wherein said context data comprises subscription data and/or security data relating to the mobile terminal.

6. The method according to any of claims 4 or 5, wherein the external mobility management function delegates at least one function to the mobility management function of the access point.

7. The method according to claim 6, wherein the at least one function comprises the functionality for session management of at least one bearer.

8. The method according to any of claims 4 to 7, wherein the access point provides a proxy MME function to coordinate processing between the external mobility management function and the mobility management function of the access point.

9. The method according to claim 8,

- wherein the proxy MME function obtains a PDN connectivity request from the mobile terminal providing an access point name;

- wherein the proxy MME function checks whether a local breakout is admissible for said access point name and in the affirmative, the PDN connectivity request is forwarded to the mobility management function of the access point.

10. The method according to any of claims 8 or 9, wherein the proxy MME function forwards an NAS message received to the external mobility management function in case it is no PDN connectivity request or in case it does not belong to a local breakout bearer.

11. The method according to any of the preceding claims, wherein a security status between the mobility management function of the access point and the external mobility management function is synchronized.

12. The method according to any of the preceding claims, wherein the mobility management function of the access point controls a gateway functionality of the access point .

13. A device comprising a and/or being associated with a processor unit and/or a hard-wired circuit and/or a logic device that is arranged such that the method according to any of the preceding claims is executable thereon .

14. The device according to claim 13, wherein said device is a communication device, in particular a or being associated with an access point.

15. A communication system comprising the device according to any of claims 13 or 14.