# Patent

## Title
Selecting a serving gateway

## Abstract

A system and method are provided for enabling a mobile device to establish a local IP access on a packet data network connection on a femto cellular access network. A local server gateway and a macro server gateway are coupled to the femto cellular access network. A mobility management entity is coupled to the femto cellular access network, the local server gateway and the macro server gateway. The mobility management entity obtains a status mode of the mobile device and a location of the mobile device transmitted on the femto cellular access network. The mobility management entity selects one of the local server gateway and the macro server gateway based on the status mode of the mobile device and the location of the mobile device.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Submission Under 35 U.S.C. §371 for U.S. National Stage Patent Application of International Application Number: PCT/CA2010/000678, filed May 5, 2010 entitled “OPTIMIZING A SERVING GATEWAY LOCATION IN A HOME EVOLVED NODE B WITH LOCAL IP ACCESS,” which claims priority to U.S. Provisional Application Ser. No. 61/175,169, filed May 4, 2009, the entirety of both which are incorporated herein by reference.


FIELD OF THE INVENTION
This invention relates to femto cell networks, and more particularly to a system and method of optimizing a server gateway location for home evolved Node-B (“eNB”) devices having local Internet Protocol access.
BACKGROUND OF THE INVENTION
Wireless carriers employ cellular towers to establish large cells for wireless communications over vast physical areas, such as metropolitan or rural areas. The large cells or macro cells may cover areas of 1 km to 5 km in diameter. A cellular tower broadcasts wireless signals to and receives wireless signals from user equipment or mobile handsets that are located throughout the macro cells.
Various structures are located within the macro cell environment that obstruct, reflect or otherwise interfere with the wireless signals. For example, users typically attempt to use mobile devices inside structures such as homes and commercial establishments, among other structures. These structures may be constructed of high loss material, such as concrete or metal that block wireless signals from penetrating the structures. Reception within these structures is often poor and unreliable due to weak wireless signal strength. Poor reception is associated with inferior quality of service by the mobile user. Femto cells or micro cells are located within these high loss structures to route signal transmissions through existing broadband backhaul infrastructure to the macro network. Data may be transported wirelessly between the femto cells and the macro cells via a macro Serving Gateway (“SGW”) and a local packet data network gateway (“PGW”) using an S1-U interface. In this case, the data travels outside the femto cell to the macro SGW and back inside the femto cell to the local PGW. This is known a traffic tromboning and is undesirable because it adds latency to data communications.
What is desired are systems and methods of optimizing a Serving Gateway location associated with femto cells. It is also desired to have systems and methods of avoiding traffic tromboning on a S1-U interface and avoiding frequent Serving Gateway relocation between a home premises and a macro environment during interrupted coverage at the home premises.
SUMMARY OF THE INVENTION
The present invention advantageously provides a method and system for optimizing a location of the serving gateway on a local network or a macro network based on a status mode of the user equipment and a location of the user equipment. The invention provides a system for enabling a mobile device to establish IP access on a packet data network connection using a femto cellular access network. A femto cellular access network is provided and is communicatively coupled to a local server gateway and a macro server gateway. A mobility manager is communicatively coupled to the femto cellular access network and is in communication with the local server gateway and the macro server gateway. The mobility manager obtains a status mode of the mobile device and a location of the mobile device transmitted on the femto cellular access network. The mobility manager selects one of the local server gateway and the macro server gateway based on the status mode of the mobile device and the location of the mobile device.
According to another embodiment, the invention provides a system for enabling a mobile device that is coupled to a macro cellular network to establish an IP access on a packet data network connection using a femto cellular access network. The macro cellular access network is communicatively coupled to a local server gateway and a macro server gateway. A mobility manager is communicatively coupled to the macro cellular access network and is in communication with the local server gateway and the macro server gateway. The mobility manager obtains a status mode of the mobile device and a location of the mobile device transmitted on the macro cellular access network. The mobility manager selects one of the local server gateway and the macro server gateway based on the status mode of the mobile device and the location of the mobile device.
According to yet another embodiment, the invention provides a method of using a femto cell to establish IP access for a mobile device on a packet data network connection using one of a local server gateway and a macro server gateway. A mobility manager determines a status of the mobile device and determines a location of the mobile device. The mobility manager communicates with the local server gateway and the macro server gateway and selects one of the local server gateway and the macro server gateway based on the status of the mobile device and the location of the mobile device.



BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
FIG. 1 illustrates a block diagram of an in-home local IP access network architecture having a local PDN connection and a local PGW, in accordance with the principles of the present invention;
FIG. 2 is a block diagram of an away-from-home remote access architecture having an external PDN connection and a local PGW, in accordance with the principles of the present invention;
FIG. 3 is a flow diagram of a service flow for relocating a servicing gateway to a macro environment when user equipment is set to idle mode while located within an operating range of a local network, in accordance with the principles of the present invention;
FIG. 4 is a block diagram of an in-home local IP access network architecture having an external PDN connection and an external PGW, in accordance with the principles of the present invention;
FIG. 5 is a block diagram of an away-from-home remote access architecture having an external PDN connection and an external PGW, in accordance with the principles of the present invention;
FIG. 6 is a flow diagram of a service flow for relocating a servicing gateway between a macro environment and a local environment (or vice versa) when user equipment activates or de-activates a local PDN connection while in the local environment, in accordance with the principles of the present invention;
FIG. 7 is a block diagram of an in-home local IP access network architecture having a local PDN connection and an local PGW, in accordance with the principles of the present invention;
FIG. 8 is a block diagram of an away-from-home remote access architecture having a local PDN connection and a local PGW, in accordance with the principles of the present invention.



DETAILED DESCRIPTION OF THE INVENTION
As is shown in FIG. 1, the invention provides femto base stations or home evolved Node-B (“e-NB”) devices 102 that are positioned inside structures 101 to improve cellular quality of service and to enable communications with devices coupled to a home network. For example, the femto base stations 102 may be positioned inside residential or commercial structures 101, among other structures. The femto base stations 102 may operate in the femto power range of about +15 dBm and may provide an operation range of approximately 50 meters. The invention also provides macro e-NBs 202 that are positioned within the macro cell, which is located outside the residential or commercial structures.
Some embodiments may be described using the expression “coupled” and “connected” along with their derivatives. For example, some embodiments may be described using the term “connected” to indicate that two or more elements are in direct physical or electrical contact with each other. In another example, some embodiments may be described using the term “coupled” to indicate that two or more elements are in direct physical or electrical contact. The term “coupled” or “communicatively coupled,” however, may also mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other. The embodiments disclosed herein are not necessarily limited in this context.
The femto base stations 102 and the macro e-NBs 202 communicate with user equipment (“UE”) 106, such as cellular telephone, personal digital assistants, or other UE over wireless cellular technologies. The femto base stations 102 may use existing broadband backhaul infrastructure to access networks, such as the Internet and/or macro networks, through the publicly-switched telephone network. The femto base stations 102 may be communicatively coupled to digital subscriber line (“DSL”) devices or cable modems and to local area networks (“LANs”) 108.
The invention may operate using existing cellular technologies, such as CDMA2000 1xRTT, evolution-data optimized (“EV-DO”) and long-term evolution (“LTE”) networks, among other cellular networks.
The UE 106 may include a wide range of electronic devices, including but not limited to mobile phones, personal data assistants (“PDA”) and similar devices, which use the various communication technologies such as advanced mobile phone system (“AMPS”), time division multiple access (“TDMA”), code division multiple access (“CDMA”), global system for mobile communications (“GSM”), general packet radio service (“GPRS”), 1x evolution-data optimized (abbreviated as “EV-DO” or “1xEV-DO”) and universal mobile telecommunications system (“UMTS”). The UE 106 also includes hardware and software suitable to support the control plane functions needed to engage in wireless communication with the femto base stations 102 and the macro eNBs 202. Such hardware can include a receiver, transmitter, central processing unit, storage in the form of volatile and nonvolatile memory, and input/output devices, among other hardware.
The invention is directed to deploying a plurality of femto cells 102 within a macro cell or macro environment. While the various femto base stations 102 are components of the overall communications network, each femto cell is separate and distinct from the existing macro cell and any adjacent femto cells. During mobility, the system hands UE communication sessions from a femto cell 102 to the macro cell, or vice versa. Alternatively, the system may hand UE communication sessions from a femto cell to another femto cell.
According to one embodiment, the macro cells and the femto cells employ handoff procedures that are initiated for various reasons, including when signal strength measurements originating in the active network, such as the cellular network or the femto network, fall below pre-selected threshold parameters. The UE 106 may detect a weak signal strength emanating from the “active” access network and may initiate a handoff to the “idle” access network, such as the femto base station network or the cellular network, having a stronger signal strength. This may be performed by reporting the weak signal to the active access network.
Alternatively, the handoff procedures may be initiated to off-load terminal device traffic from the cellular network to the femto base station network. The femto base station 102 is a personal and dedicated base station for each corresponding structure, such as a home or commercial building 101. The femto base stations 102 independently support network traffic, along with the cellular network that supports the macro cell.
The femto base station 102 may be directly or indirectly coupled to a hub/switch, DSL/cable modem and/or a router (not shown). These devices may include separate hardware devices or a combination of hardware devices. The hub/switch and router may be provided to share system resources with the UE 106. Shared resources may include terminal devices, such as personal computers, laptops, printers, and media players, among other terminal devices.
The invention provides the femto base stations 102 having a local packet data network (“PDN”) Gateway (“PGW”) 112 with a home access point name (“APN”) and a local Serving Gateway (“SGW”) 114 that directs in-home data requests received through the local area network 108. A single APN may be assigned to a plurality of subscribers and may be resolved to a target local PGW 112. Alternatively, a plurality of APNs may be assigned to a plurality of subscribers.
The UE 106 is provided with local IP access on a dedicated packet data network (“PDN”) connection. The PDN connections may include a local PDN connection, an external PDN connection or both local and external PDN connections. The UE 106 may be placed in one of two modes, an active mode and an idle mode. Depending on the type of local IP access and the state of the UE 106, it is desirable to optimize a location of a Serving Gateway (SGW) location, by selectively assigning the SGW location into a local environment or a macro environment. The invention provides several optimizations. For example, when the UE 106 is placed in idle mode while located in a local environment, a mobility management entity (“MME”) or mobility manager may relocate the SGW to the macro environment. When the UE 106 is placed in active mode and is connected through a local PDN connections, the MME may relocate the SGW to the local environment to streamline data transport or avoid tromboning. When the UE 106 de-activates the local PDN connections while still engaged to an external PDN connection, the MME may relocate the SGW to the macro environment to eliminate frequent SGW relocations due to poor signal receptions.
Long-term evolution (“LTE”) and evolved high rate packet data (“eHRPD”) are exemplary fourth generation (“4G”) technologies that improve the universal mobile telecommunications system (“UMTS”) mobile telephone standard by providing a simplified, all-packet architecture. The UMTS technology supports mobile Internet protocol (“IP”) services, such as music downloads, video sharing, voice over IP broadband access, and other IP services to laptops, personal digital assistants (“PDAs”) and other user equipment 106. The LTE enhances current UMTS capabilities by providing improved efficiency, lower costs, increased peak data rates, lower latency, improved services and improved integration with other open standards. The invention further supports femto cellular access networks, including an LTE network, an EVDO or eHRPD network connected to an evolved packet core (“EPC”), WiMax 802.16e/m connected to EPC.
It should be appreciated that, although the invention is described with reference to the LTE network, the principles of the invention may be adapted by one of skill in the art to include other networks, such as WiMAX (IEEE 802.16) networks, other CDMA2000 networks and any other networks known in the art or later developed.
Referring now to the drawing figures in which like reference designators refer to like elements, FIG. 1 illustrates an exemplary block diagram of a system designated generally as “100” that provides a local packet data network connection and includes UE 106 that communicates on a local area network 108 within a femto cell located inside a structure 101. The UE 106 may be assigned a local area IP address. The femto base station 102 includes a local packet data network (“PDN”) Gateway (“PGW”) 112 having a home access point name (“APN”) and a local Serving Gateway (“SGW”) 114 that routes in-cell data requests to an in-home LAN 108. The ‘home-based’ PDN or local PGW 112 permits the UE 106 to communicate over the local area network 108.
The local PGW 112 provides the UE 106 with direct connectivity to the backhaul IP infrastructure using the femto base station 102 and the home LAN 108. The local PGW 112 and the local SGW 114 eliminate the need to send data from the UE 106 across to an operator's macro network. Rather, Internet traffic may be re-routed from a service provider's wireless network to the backhaul IP infrastructure. The femto base station 102, the local PGW 112 and the local SGW 114 may be configured to enable the UE 106 to access one or more packet data networks (“PDN”) concurrently through one or more local PGWs 112.
To support this capability, in addition to supporting a home or local SGW 114 and local PGW 112, the femto base station 102 supports the S5 and S11 interface, among other interfaces. The local PGW 112 and the local SGW 114 communicate using the S5 interface. The femto gateway (“HeNB GW”) 120, in addition to aggregating the S1-MME interface, also may be enhanced to support S11 and S5 aggregation.
The femto base stations 102 may include a central processing unit (“CPU”), transmitter, receiver, I/O devices and storage, such as volatile and nonvolatile memory, to implement the functions described herein. The femto base stations 102 may communicate with the UE 106 over a radio interface.
The femto base station 102 may be coupled to the HeNB GW 120 through IPsec tunnel 116. IPsec tunnel 116 provides a secure public network connection and prevents wiretapping, traffic manipulation or other security threats. The HeNB GW 120 is an interface to external networks and may be coupled to a plurality of femto base stations 102. For example, the HeNB GW 120 may be coupled to and may manage hundreds or thousands of femto base stations 102. Additionally, the HeNB GW 120 may be configured as an authenticator that grants local breakout authorization.
According to one embodiment, a mobility management entity (“MME”) 125 may be provided as a control plane entity to manage the UE 106 within the LTE network and to authenticate the UE 106. The MME 125 may be coupled to the femto base station 102 and the local SGW 114. The MME 125 is a signaling only entity, such that IP data packets that originate from the UE 106 are not processed at the MME 125. The MME 125 may perform various functions, including non-access stratum (“NAS”) signaling; NAS signaling security; tracking area list management for mobile terminals in idle and active mode; packet data network gateway (“PDN-GW”) selection and Serving Gateway (“S-GW”) selection; roaming; authentication; and bearer management functions; among other functions.
The local GW or HeNB GW 120 communicates with packet data network gateway (“PDN GW”) or (“PGW”) 130. The communication may be performed using an S5 reference point, among other interfaces. PGW 130 provides the UE 106 with access to one or more PDN concurrently through one or more PGWs 130. The PGW 130 provides an anchor point for the UE 106 and remains in communication with the UE 106 throughout a communication session, regardless of whether the UE 106 moves to different network nodes. The PGW 130 is configured not to receive data that is transmitted using the femto base station 102 between the UE 106 and any in-home network devices. External Internet traffic may be routed to the in-home network devices through the in-home or local PGW 112 or the PGW 130, based on operator decision. The PGW 130 may perform various functions, including packet filtering on a per-user basis; interception; mobile terminal IP address allocation, uplink (“UL”) and downlink (“DL”) service level charging, gating and rate enforcement, and transport level packet marking in the downlink, among performing other functions. As used herein, “uplink” refers to communications from UE 106 and “downlink” refers to communications to UE 106. Additionally, the PGW 130 may manage mobility between 4G networks and non-4G networks.
FIG. 2 is a schematic block diagram of a system designated generally as “200,” for providing an external packet data network connection and enabling the UE 106, which is located at a remote location outside of a femto cell range, to communicate with the in-home LAN 108. In other words, the system 200 enables a remote UE 106 that is connected to the macro network to access the in-home LAN 108. The external PDN connectivity enables the UE 106 to specify an internal or in-home PDN as a target PDN. The macro network includes a Serving Gateway (“SGW”) 204 that creates an S5 tunnel or “inbound” S5 interface to the in-home PDN via the HeNB GW 120, the IPsec 116 and the local PGW 112. The PGW 112 provides the remote UE 106 with access to the local network 108.
The S5 tunnel or “inbound” S5 interface provides a communication path from the SGW 204 to the HeNB GW 120 in order to facilitate routing of a request to the local PGW 112. The UE 106 communicates with the macro e-NB 202 in the macro network, where the UE 106 may be authenticated and data packets are forwarded to the SGW 204. The SGW 204 analyzes the data packets from the UE 106 and determines whether to direct the received data packets to the local PGW 112 through the HeNB GW 120. The UE 106 may acquire an IP address for itself on both the remote network and the local or home-based network 108 through, for example, a dynamic host configuration protocol (“DHCP”) or another address management protocol. The HeNB GW 120 may direct the data packets to the local PGW 112. The local PGW 112 may send the data packets to the in-home LAN 108.
The SGW 204 may perform various functions, including being a local mobility anchor point for inter-eNB handoffs; mobility anchoring for inter-4G mobility; interception; packet routing and forwarding; transport level packet marking in the uplink and downlink; uplink and downlink per mobile terminal, PDN and quality of service class identifier (“QCI”); and accounting on user and QCI granularity for inter-operator charging; among performing other functions.
According to one embodiment, the MME 125 may be provided as a control plane entity to manage the UE 106 within the LTE network and to authenticate the UE 106. The MME 125 may be coupled to the macro e-NB 202 and the SGW 204. The MME 125 may manage packet forwarding uplink and downlink between the PGW 130 and the macro e-NB 202, among performing other functions. The MME 125 is a signaling only entity, such that IP data packets that originate from the UE 106 are not processed at the MME 125. The MME 125 may perform various functions, including non-access stratum (“NAS”) signaling, NAS signaling security, tracking area list management for mobile terminals in idle and active mode, packet data network gateway (“PDN-GW”) selection and Serving Gateway (“S-GW”) selection, roaming, authentication, and bearer management functions among other functions.
An IP multimedia subsystem core (not shown) may be coupled to the PGW 130 to handle calls or sessions, real-time session negotiation and management. A home subscriber server (not shown) may be coupled to the MME 125 to maintain a physical location of the user. The HSS may be implemented with a master database having subscription and location information.
Together, the systems illustrated in FIGS. 1 and 2 provide the UE 106 with both a local PDN connection in system 100 and an external PDN connection in system 200. When the UE 106 operates in an active mode using a local PDN connection within range of the in-home LAN 108, a desired location for the Serving Gateway is within the in-home LAN 108 at local SGW 112, as illustrated in FIG. 1. By locating the Serving Gateway at local SGW 112 under these conditions, the invention streamlines data transport and avoids traffic tromboning on the S1-U interface between the femto base station 102 and the SGW 204. By contrast, when the UE 106 operates in an active mode using an external PDN connection in the macro environment, a desired location for the Serving Gateway is within the macro cell at SGW 204, as illustrated in FIG. 2. If the UE 106 transitions from the in-home LAN 108 to the macro environment (or vice versa) while the UE 106 is operating in active mode, the SGW relocation may be performed using existing 3GPP procedures. Otherwise, if the UE 106 transitions from the in-home LAN 108 to the macro environment (or vice versa) while the UE 106 is operating in idle mode, conventional systems maintain the SGW in the environment where the UE 106 was active last.
According to one embodiment, the invention relocates the SGW to the macro environment from the local environment when the UE 106 is set to an idle state while operating within range of a local network 108. An exemplary process of relocating the Serving Gateway on the network is discussed with reference to FIG. 3 for an LTE network. The user equipment 106, when placed in an idle state, may initiate relocation of the SGW to the macro environment upon S1 release. A Context Release Request is routed in step S301 using a control plane signaling protocol S1 Application Part (“S1AP”) between the HeNB 108 and the MME 125 to request release an S1UE context. According to one embodiment, an Update Bearer Request is routed between the MME 125 and the local SGW 114 in step S303 and an Update Bearer Response is routed between the local SGW 114 and the MME 125 in step S305.
A Context Release Command is routed in step S307 using a control plane signaling protocol S1 Application Part (“S1AP”) between the MME 125 and the HeNB 108 to release an S1UE context. In step 309, the HeNB 108 directs a Radio Resource Control (RRC) connection release to the user equipment 106. In step 311, the HeNB 108 issues a Context Release Complete signal to the MME 125 using a control plane signaling protocol S1 Application Part (S1AP) to indicate release of the S1UE context. In step 313, the MME 125 issues a Create Bearer Request to SGW 204 and in step 315 the SGW 204 issues a Create Bearer Response to the MME 125. In step 317, the MME 125 issues a Delete Bearer Request to the local SGW 114 and in step 319 the local SGW 114 issues a Delete Bearer Response to the MME 125. Upon completion of step 319, the UE 106 is relocated from local SGW 114 to macro SGW 204 when set to the idle state while operating in the in-home LAN 108.
FIG. 4 is a schematic block diagram of a system designated generally as “400,” for providing an external packet data network connection. The system 400 includes a UE 106 that communicates with a local area network 108 within a femto cell located inside a structure 101. The UE 106 may be assigned a local area IP address and may communicate with the in-home LAN 108. For example, the UE 106 may acquire an IP address on the LAN 108 through, for example, a dynamic host configuration protocol (“DHCP”) or another address management protocol. The system 400 enables the UE 106 to communicate with the femto base station 102, which is coupled to the Serving Gateway (“SGW”) 204 on the macro network using an S1-U interface via the HeNB GW 120 and the IPsec 116. When using the external PDN connection, the system 400 uses the SGW 204 in the macro environment even when the UE 106 is operating within range of the LAN 108. The SGW 204 analyzes the data packets received from the UE 106 and determines whether to direct the received data packets to the macro PGW 130. If the UE 106 activates a local PDN connection in addition to the external PDN connection, the system 400 may relocate the Serving Gateway to local Serving Gateway in order to avoid traffic tromboning.
The SGW 204 may perform various functions, including serving as a local mobility anchor point for inter-eNB handoffs, mobility anchoring for inter-4G mobility, interception, packet routing and forwarding, transport level packet marking in the uplink and downlink, uplink and downlink per mobile terminal, PDN and quality of service class identifier (“QCI”), and accounting on user and QCI granularity for inter-operator charging, among performing other functions.
According to one embodiment, the MME 125 may be provided as a control plane entity to manage the UE 106 within the LTE network and to authenticate the UE 106. The MME 125 may be coupled to the femto base station 102 and the SGW 204. The MME 125 may manage packet forwarding uplink and downlink between the PGW 130 and the femto base station 102, among performing other functions. The MME 125 is a signaling only entity, such that IP data packets that originate from the UE 106 are not processed at the MME 125. The MME 125 may perform various functions, including non-access stratum (“NAS”) signaling; NAS signaling security; tracking area list management for mobile terminals in idle and active mode; packet data network gateway (“PDN-GW”) selection and Serving Gateway (“S-GW”) selection; roaming; authentication; and bearer management functions; among other functions.
FIG. 5 is a schematic block diagram of a system designated generally as “500,” for providing an external packet data network connection. The system 500 includes a UE 106, which is located at a remote location outside of a femto cell range. The UE 106 may be assigned an IP address from a remote network. For example, the UE 106 may acquire an IP address through a dynamic host configuration protocol (“DHCP”) or another address management protocol.
The system 500 enables the UE 106 to communicate with the macro e-NB 202, which is coupled to the Serving Gateway (“SGW”) 204 on the macro network using an S1-U interface. The SGW 204 analyzes the data packets received from the UE 106 and determines whether to direct the received data packets to the macro PGW 130. The SGW 204 may perform various functions, including being a local mobility anchor point for inter-eNB handoffs; mobility anchoring for inter-4G mobility; interception; packet routing and forwarding; transport level packet marking in the uplink and downlink; uplink and downlink per mobile terminal, PDN and quality of service class identifier (“QCI”); and accounting on user and QCI granularity for inter-operator charging; among performing other functions.
According to one embodiment, the MME 125 may be provided as a control plane entity to manage the UE 106 within the LTE network and to authenticate the UE 106. The MME 125 may be coupled to the macro e-NB 202 and the SGW 204. The MME 125 may manage packet forwarding uplink and downlink between the PGW 130 and the macro e-NB 202, among performing other functions. The MME 125 is a signaling only entity, such that IP data packets that originate from the UE 106 are not processed at the MME 125. The MME 125 may perform various functions, including non-access stratum (“NAS”) signaling; NAS signaling security; tracking area list management for mobile terminals in idle and active mode; packet data network gateway (“PDN-GW”) selection and Serving Gateway (“S-GW”) selection; roaming; authentication; and bearer management functions; among other functions.
The systems illustrated in FIGS. 4 and 5 provide the UE 106 with external PDN connections. When the UE 106 operates in an active mode using an external PDN connection within range of the in-home LAN 108, a desired location for the Serving Gateway is within the macro cell at SGW 204, as illustrated in FIG. 4. Similarly, when the UE 106 operates in an active mode using an external PDN connection in the macro environment, a desired location for the Serving Gateway is within the macro cell at SGW 204, as illustrated in FIG. 5. For the systems of FIGS. 4 and 5 in which the UE 106 is provided with external PDN connections only, an ideal SGW location is in the macro environment, regardless of whether the UE 106 is operating within range of the in-home LAN 108 or within the macro cell.
An exemplary process of relocating the Serving Gateway between a home environment and a macro environment (and vice versa) is discussed with reference to FIG. 6 for an LTE network. The MME 125 may initiate relocation of the SGW between a home environment and a macro environment (and vice versa). In step 601, a Create Bearer Request is routed between the MME 125 and the local SGW 114 (or SGW 204). In step S603 a Create Bearer Response is routed between the local SGW 114 (or SGW 204) and the MME 125. A Relocation Request is routed in step S605 using a control plane signaling protocol S1 Application Part (S1AP) between the MME 125 and the HeNB 108 to request relocation of the SGW. A Relocation Response is routed in step S607 using a control plane signaling protocol S1 Application Part (S1AP) between the HeNB 108 and the MME 125 to relocate the SGW. In step 609, the MME 125 issues an Update Bearer Request signal to the local SGW 114 (or SGW 204). In step 611, the local SGW 114 (or SGW 204) issues an Update Bearer Response signal to the MME 125. In step 613, the MME 125 issues a Delete Bearer Request to SGW 204 (or local SGW 114) and in step 615 the SGW 204 (or local SGW 114) issues a Delete Bearer Response to the MME 125. Upon completion of step 615, the local SGW 114 (or SGW 114) is relocated to the SGW 114 (or local SGW 114) when the UE 106 is operating in the active state and the local PDN connection is de-activated (or the local PDN connection is activated).
FIG. 7 is a schematic block diagram of a system designated generally as “700,” for providing a local packet data network connection. The system 700 includes a UE 106 that communicates with a local area network 108 within a femto cell located inside a structure 101. The UE 106 may be assigned a local area IP address and may communicate with the in-home LAN 108. For example, the UE 106 may acquire an IP address on the LAN 108 through, for example, a dynamic host configuration protocol (“DHCP”) or another address management protocol.
The system 700 enables the UE 106 to communicate with the femto base station 102, which is coupled to the local SGW 114 and the local PGW 112 on the local network 108. The local PGW 112 provides the UE 106 with direct connectivity to the backhaul IP infrastructure using the femto base station 102 and the home LAN 108. The femto base station 102, the local PGW 112 and the local SGW 114 may be configured to enable the UE 106 to access one or more packet data networks (“PDN”) concurrently through one or more local PGWs 112.
The femto base station 102 supports the S5 and S11 interface, among other interfaces. The local PGW 112 and the local SGW 114 communicate using the S5 interface. The femto gateway (“HeNB GW”) 120, in addition to aggregating the S1-MME interface, also may be enhanced to support S11 and S5 aggregation.
The femto base station 102 may be coupled to the HeNB GW 120 through IPsec tunnel 116. IPsec tunnel 116 provides a secure public network connection and prevents wiretapping, traffic manipulation or other security threats. The HeNB GW 120 is an interface to external networks and may be coupled to a plurality of femto base stations 102. For example, the HeNB GW 120 may be coupled to and may manage hundreds or thousands of femto base stations 102. Additionally, the HeNB GW 120 may be configured as an authenticator that grants local breakout authorization.
According to one embodiment, the MME 125 may be provided as a control plane entity to manage the UE 106 within the LTE network and to authenticate the UE 106. The MME 125 may be coupled to the femto base station 102 and the local SGW 114. The MME 125 is a signaling only entity, such that IP data packets that originate from the UE 106 are not processed at the MME 125. The MME 125 may perform various functions, including non-access stratum (“NAS”) signaling; NAS signaling security; tracking area list management for mobile terminals in idle and active mode; packet data network gateway (“PDN-GW”) selection and Serving Gateway (“S-GW”) selection; roaming; authentication; and bearer management functions; among other functions.
FIG. 8 illustrates a schematic block diagram of a system designated generally as “800,” for providing an local packet data network connection. The system 800 includes a UE 106, which is located at a remote location outside of a femto cell range. The UE 106 may be assigned an IP address from a remote network. For example, the UE 106 may acquire an IP address through a dynamic host configuration protocol (“DHCP”) or another address management protocol.
The system 800 enables the UE 106 to communicate with the macro e-NB 202, which is coupled to the Serving Gateway (“SGW”) 204 on the macro network using an S1-U interface. The SGW 204 analyzes the data packets received from the UE 106 and determines whether to direct the received data packets to the local PGW 112. The SGW 204 may perform various functions, including being a local mobility anchor point for inter-eNB handoffs; mobility anchoring for inter-4G mobility; interception; packet routing and forwarding; transport level packet marking in the uplink and downlink; uplink and downlink per mobile terminal, PDN and quality of service class identifier (“QCI”); and accounting on user and QCI granularity for inter-operator charging; among performing other functions.
According to one embodiment, the MME 125 may be provided as a control plane entity to manage the UE 106 within the LTE network and to authenticate the UE 106. The MME 125 may be coupled to the macro e-NB 202 and the SGW 204. The MME 125 may manage packet forwarding uplink and downlink between the local PGW 112 and the macro e-NB 202, among performing other functions. The MME 125 is a signaling only entity, such that IP data packets that originate from the UE 106 are not processed at the MME 125. The MME 125 may perform various functions, including non-access stratum (“NAS”) signaling; NAS signaling security; tracking area list management for mobile terminals in idle and active mode; packet data network gateway (“PDN-GW”) selection and Serving Gateway (“S-GW”) selection; roaming; authentication; and bearer management functions; among other functions.
The systems illustrated in FIGS. 7 and 8 provide the UE 106 with local PDN connections. When the UE 106 operates in an active mode using a local PDN connection within range of the in-home LAN 108, a desired location for the Serving Gateway is within the femto base station 102 at local SGW 114, as illustrated in FIG. 7. By contrast, when the UE 106 operates in an active mode in the macro environment using a local PDN connection, a desired location for the Serving Gateway is within the macro cell at SGW 204, as illustrated in FIG. 8. For the systems of FIGS. 7 and 8 in which the UE 106 is provided with local PDN connections only, a desired SGW location is in the local environment while operating within range of the in-home LAN 108 and in the macro environment while operating within the macro cell.
It should be appreciated that, although the invention is described with reference to the LTE network, the principles of the invention may be adapted by one of skill in the art to migrate between any networks, including other networks, such as 1xRTT networks, EV-DO networks, UMTS networks, WiMAX (802.16) networks, other CDMA2000 networks and any other networks known in the art or later developed.
The present invention can be realized in hardware, software, or a combination of hardware and software. Any kind of computing system, or other apparatus adapted for carrying out the methods described herein, is suited to perform the functions described herein.
A typical combination of hardware and software could be a specialized computer system having one or more processing elements and a computer program stored on a storage medium that, when loaded and executed, controls the computer system such that it carries out the methods described herein. The present invention can also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which, when loaded in a computing system is able to carry out these methods. Storage medium refers to any volatile or non-volatile storage device.
Computer program or application in the present context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following a) conversion to another language, code or notation; b) reproduction in a different material form.
In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. Significantly, this invention can be embodied in other specific forms without departing from the spirit or essential attributes thereof, and accordingly, reference should be had to the following claims, rather than to the foregoing specification, as indicating the scope of the invention. It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope and spirit of the invention, which is limited only by the following claims.
It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope and spirit of the invention, which is limited only by the following claims.

## Claims

1. A system, comprising:
a mobility manager configured to communicatively couple to a femto cellular access network and configured to communicate with a local server gateway and a macro server gateway, wherein the mobility manager is configured to:
obtain a status mode of a mobile device and a location of the mobile device transmitted on the femto cellular access network; and
select one of the local server gateway and the macro server gateway for the mobile device based on the status mode of the mobile device and the location of the mobile device;

wherein the local server gateway and the macro server gateway are configured to communicatively couple to the femto cellular access network.

2. The system of claim 1, further comprising a local gateway communicatively coupled to the femto cellular access network, wherein the local gateway is configured to receive data packets from the femto cellular access network and route the data packets to one of the local server gateway or the macro server gateway.

3. The system of claim 1, wherein the status mode of the mobile device includes one of an active mode and an idle mode.

4. The system of claim 1, wherein the local server gateway is positioned in a local environment.

5. The system of claim 1, wherein the macro server gateway is positioned in a macro environment.

6. The system of claim 1, wherein the femto cellular access network includes one of an long-term evolution (LTE) network, an evolution-data optimized (EVDO) network connected to an evolved packet core (EPC), and a WiMax 802.16e/m network connected to the EPC.

7. The system of claim 2, wherein the local gateway is associated with at least one access point name.

8. The system of claim 7, wherein a single access point name is assigned to a plurality of subscribers.

9. The system of claim 1, wherein the mobility manager is further configured to:
select the macro server gateway for the mobile device based on determining that the device is located in a local environment and that the device is in an idle mode.

10. A mobile device configured to communicatively couple to a femto cellular access network and configured to:
utilize a local server gateway to access a packet data network in response to operating in a first mode at a particular location; and
utilize a macro server gateway to access a packet data network in response to operating in a second mode at the particular location;
wherein the local server gateway and the macro server gateway are communicatively coupled to the femto cellular access network.

11. The system of claim 10, further comprising a local gateway communicatively coupled to the femto cellular access network, the local gateway receiving data packets from the femto cellular access network and routing the data packets to one of the local server gateway or the femto server gateway.

12. The system of claim 10, wherein the femto cellular access network includes one of an long-term evolution (LTE) network, an evolution-data optimized (EVDO) network connected to an evolved packet core (EPC), and a WiMax 802.16e/m network connected to the EPC.

13. The system of claim 10, wherein the mobile device is configured to utilize the local server gateway or the macro server gateway in response to information generated by a mobility manager, wherein the mobility manager is communicatively coupled to the macro server gateway and the local server gateway.

14. The system of claim 10 wherein the particular location is within range of a local access point, wherein the first mode is an active mode and wherein the second mode is an idle mode.

15. The system of claim 13, wherein a plurality of access point names are assigned to a plurality of subscribers.

16. The system of claim 10, wherein the status mode of the mobile device includes one of an active mode and an idle mode.

17. A method, comprising:
determining a status of a mobile device;
determining a location of the mobile device;
communicating with a local server gateway and a macro server gateway;
selecting one of the local server gateway and the macro server gateway to provide IP access to the mobile device on a packet data network connection based on the status of the mobile device and the location of the mobile device.

18. The method of claim 17, wherein determining the status of the mobile device includes receiving an indication of one of an active status or an idle status.

19. The method of claim 18, wherein determining the location of the mobile device includes receiving an indication of one of a macro environment and a local environment.

20. The method of claim 19, further comprising selecting the macro server gateway when the status of the mobile device is the idle status and the location of the mobile device is the local environment.