WO2010057527A1

WO2010057527A1 - Apparatus, method and program for service selective usage of interfaces

Info

Publication number: WO2010057527A1
Application number: PCT/EP2008/065867
Authority: WO
Inventors: Frank-Uwe Andersen; Morten SCHLÄGER
Original assignee: Nokia Siemens Networks Gmbh & Co. Kg
Priority date: 2008-11-19
Filing date: 2008-11-19
Publication date: 2010-05-27

Abstract

Embodiments provide a method and apparatus configured to detect an alternative link to a terminal, to establish a tunnel for at least part of the alternative link, and/or to modify at least one routing table for use of the alternative link and at least one further link. The apparatus may e.g. be at least one of an access router, a gateway, a packet data gateway, a packet data network gateway.

Description

APPARATUS, METHOD AND PROGRAM FOR SERVICE SELECTIVE USAGE OF INTERFACES

FIELD OF TECHNOLOGY AND BACKGROUND

The invention generally relates to e.g. communication and methods, apparatuses, network elements, systems and programs e.g. of or for communication.

In future, the network landscape may be heterogeneous. E.g. several billion users may generate a 100-fold traffic increase compared with today's networks, whereas the costs per byte will continue to decrease. To cope with increased traffic at reasonable cost and expenditure, existing network resources are to be efficiently used. This may involve selecting and using more than one connection at the same time in one device, including wireless/wireless or fixed/wireless access types for general optimization of resource usage and also complementary use.

As an example, third generation partnership project, 3GPP, provides standardization, for Release 8 and later, of a function and functional entity called network discovery and selection function, and mobile internet protocol, Mobile IP (see e.g. TR 23.402) to allow terminals to discover available networks and select an appropriate network. Mobile IP is used to support mobility between different technologies.

In a heterogeneous network landscape or overlapping networks, locations may exist where more than one technology or access type is available at the same time, e.g. at a wireless or WIFI hotspot wireless local area network, WLAN, and third generation, 3G, coverage may be provided. 3GPP Release 8, Rel8, defines in TR 23.402 means and functions to select networks (network discovery and selection function, NWDSF) and to handover to and from non-3G networks (mobile-IP/ proxy mobile IP) .

In such cases end devices may support mobile IP, or support of proxy mobile IP may be provided, or only applications that support application level roaming may conduct a handover. Independent of the applied mobility support only one of the available interfaces is presently used at the same time.

As different applications have different QoS requirements and WLAN does not provide QoS guarantees, it may often not be possible to offload traffic from 3G to WLAN due to QoS requirements. Further if WLAN quality turns out to be too bad, a fast fall back to 3G may be appropriate.

In case of application level roaming, if the point of attachment is changed (e.g. handover from WLAN to 3G) the IP address is also changed. As the transport protocol of the Internet, e.g. transmission control protocol, TCP, or user datagram protocol, UDP, may use the IP addresses to map incoming packets to contexts (demultiplexing) a change of the IP address may result in interception/termination of all transport connections. Applications supporting application level roaming may detect a change of the local IP address (e.g., by a trigger from device management) and restart the connection with the new IP address without user interaction. With application level roaming, ALR, the application must support the reestablishment of a connection after a handover hence terminal support is needed and the mechanism is not available for all applications. To support multi-homing application, a logic, means or function, may be provided for deciding when to use what interface. This logic may on the one hand be based on external information. On the other hand frequent/fast handovers between the technologies should be avoided. Especially it is not possible to send packets of one application on either of the two paths.

Regarding mobile IP, MIP, a terminal has a home address. If the terminal is attached to a foreign network it registers its current address (care of address) with the home agent in the home network (binding) . Classical Mobile IP only supports a single binding, hence a terminal may only use a single interface. For Mobile IP with multiple care of address support (MIP with MCoA) , modifications to both the end-system and the network may be required. Also, when the mobile node/terminal is at home (attached to home network) mobile IP may be inactive. E.g. if 3G is home network it may not be possible to use WLAN as foreign network. Although IETF is standardizing extensions to support Mobile IP with multiple care-of-addresses the deployment of these modifications may require changes at the terminal and the network elements. Also this does not change the behaviour when attached to home network.

In case of proxy mobile IP, in order to enable mobility for terminals that do not support mobile IP, proxy MIP is provided. With this approach the terminal may always see its home environment (IP address) independent from the point of attachment. The use of PMIP as an alternative to client-MIP is currently discussed and standardized in 3GPP TS 23.402 for intra-SAE mobility, but also for non-3G access.

SUMMARY

In accordance with one or more embodiments of the invention parallel usage of interfaces is provided so as to overcome e.g. the above problems. Embodiments provide one or more apparatuses, method and programs for service selective usage of e.g. two or more parallel connected interfaces. In accordance with one or more embodiments, parallel can also mean that all traffic is routed via one of the interfaces, e.g. the non-3G interface, and the other interface, e.g. 3G interface, is kept active to allow fast fallback.

In accordance with one or more embodiments, an apparatus is configured to detect an alternative link to a terminal, to establish a tunnel for at least part of the alternative link, and/or to modify at least one routing table for use of the alternative link and at least one further link.

In accordance with one or more embodiments, the apparatus may e.g. be at least one of an access router, a gateway, a packet data gateway, a packet data network gateway.

In accordance with one or more embodiments the, or an, apparatus may e.g. be configured to establish a tunnel between a packet data network gateway and an access router or gateway, or for a layer 3 hop, or for the last layer 3 hop before the terminal, or to a tunnel endpoint closest to the terminal .

In accordance with one or more embodiments the, or an, apparatus may comprise at least one or more of the following in any arbitrary combination: a gateway, packet data gateway, access router or packet data network gateway equipped with tunnel functionality e.g. IP, layer 2, a gateway, packet data gateway, access router or packet data network gateway equipped with control module for routing engine, a gateway, packet data gateway, access router or packet data network gateway equipped with decision logic or function responsible for flow mapping, a decision logic or function responsible for flow mapping connected to monitoring parts or functions of a gateway to a data or internet protocol network, a gateway, packet data gateway, access router or packet data network gateway equipped with monitoring functionality to observe connectivity, a gateway, packet data gateway, access router or packet data network gateway equipped with feedback loop to decision logic, a control plane, configured to monitor at least one access node and load in case a mobile node has two or more active interfaces .

In accordance with one or more embodiments the, or an, apparatus according to any one of the preceding claims, configured to at least one or more of the following in any arbitrary combination: detection of two or more parallel accesses, optionally by a subscriber device, determine a last internet protocol hop or a tunnel endpoint closest to a mobile device, or a node in direct connection with the mobile device, use a signal path for sending the IP address of the access node to which the mobile device is directly connected to an other tunnel end point in a gateway or packet data network gateway, use a command returning layer 3 hops down to the mobile device . In accordance with one or more embodiments, an apparatus may be configured to at least one or more of the following in any arbitrary combination: register, contact, for example by or via a gateway, or initiate or control to contact, a packet data network gateway to prepare simultaneous usage of interface, send a modifying request to the gateway optionally including at least one of subscriber identifier, reference number and preferred tunnelling protocol, check whether a subscriber is allowed to use multiple interfaces, create a tunnel or tunnel end-point, modify a local routing table to forward packets with destination address of one network to mobile terminal using another network access, load one or more traffic filters from a profile and redirect packets comprising an address of the one network to traffic filters, traffic filter forwards packets either to the tunnel or to the one network.

In accordance with one or more embodiments the, or an, apparatus may e.g. be configured to at least one or more of the following in any arbitrary combination: provide a flow distribution of one or more flows to a terminal, route one or more packets to a user via a first access or 3G access or a second access or non-3G access in accordance with a scheduling, the scheduling depending on local policies, the scheduling implementing one or more of the following: send all packets via the second access, send all packets such as transmission control protocol packets with a certain segment size or a segment size lower or higher than a threshold via the second access, send packets with certain internet protocol 5-tuple via the second access, send packets with certain DiffServ codepoint via the second access .

In accordance with one or more embodiments the, or an, apparatus may be configured to at least one or more of the following in any arbitrary combination: keep available a path as a second or default path, provide monitoring, monitor at least one or more of a link quality, a number of buffered packets, a number of retransmissions, send a message to a packet data network gateway if the quality falls below one or more threshold levels, decide based on the quality level on the routing of packets via a first or second access such as 3G and non-3G, provide a host based routing wherein a network management system modifies routing tables on all routers on a path from a packet data network gateway to a last hop or packet data gateway or access router to forward packets destined to an interface of a mobile terminal towards another interface of the mobile terminal, provide support for uplink or terminal generated traffic, use an address of an alternative link on an interface of another link.

In accordance with one or more embodiments, a network is provided which comprises one or more apparatuses according to any one of the above features. In accordance with one or more embodiments, a method may comprise : detecting an alternative link to a terminal, establishing a tunnel for at least part of the alternative link, and/or modifying at least one routing table for use of the alternative link and at least one further link.

In accordance with one or more embodiments, the method may comprise establishing the tunnel between a packet data network gateway and an access router or gateway, or for a layer 3 hop, or for the last layer 3 hop before the terminal, or to a tunnel endpoint closest to the terminal.

In accordance with one or more embodiments, the or a method may comprise at least one or more of the following in any arbitrary combination: tunnel functionality for a gateway, packet data gateway, access router or packet data network gateway, a control function for a routing engine, a decision function responsible for flow mapping, a decision function responsible for flow mapping connected to monitoring parts or functions of a gateway to a data or internet protocol network, a monitoring functionality to observe connectivity, a feedback loop to decision logic, a control plane, monitoring at least one access node and load in case a mobile node has two or more active interfaces.

In accordance with one or more embodiments, the method may comprise at least one or more of the following in any arbitrary combination: detecting of two or more parallel accesses, optionally by a subscriber device , determining a last internet protocol hop or a tunnel endpoint closest to a mobile device, or a node in direct connection with the mobile device, using a signal path for sending the IP address of the access node to which the mobile device is directly connected to an other tunnel end point in a gateway or packet data network gateway, using a command returning layer 3 hops down to the mobile device, register, contact a packet data network gateway to prepare simultaneous usage of interface, send a modifying request to a gateway optionally including at least one of subscriber identifier, reference number and preferred tunnelling protocol, check whether a subscriber is allowed to use multiple interfaces, create a tunnel or tunnel end-point, modify a local routing table to forward packets with destination address of one network to mobile terminal using another network access, load one or more traffic filters from a profile and redirect packets comprising an address of the one network to traffic filters, traffic filter forwards packets either to the tunnel or to the one network, provide a flow distribution of one or more flows to a terminal, route one or more packets to a user via a first access or 3G access or a second access or non-3G access in accordance with a scheduling, the scheduling depends on local policies, the scheduling implements one or more of the following: send all packets via the second access, send all packets such as transmission control protocol packets with a certain segment size or a segment size lower or higher than a threshold via the second access, send packets with certain internet protocol 5-tuple via the second access, send packets with certain DiffServ Codepoint via the second access, keep available a path as a second or default path, provide monitoring, monitor at least one or more of a link quality, a number of buffered packets, a number of retransmissions, send a message to a packet data network gateway if the quality falls below one or more threshold levels, decide based on the quality level on the routing of packets via a first or second access such as 3G and non-3G, provide a host based routing wherein a network management system modifies routing tables on all routers on a path from a packet data network gateway to a last hop or packet data gateway or access router to forward packets destined to an interface of a mobile terminal towards another interface of the mobile terminal, provide support for uplink or terminal generated traffic, use an address of an alternative link on an interface of another link.

In accordance with one or more embodiments, a computer program product or software may comprise code means configured to carry out or implement, when run on a processor, one more or all functions of a method as mentioned above. The computer program product or software may e.g. be embodied on a computer-readable medium. Two parallel interfaces is no problem from a layer two perspective, but some issues are considered at higher layers. If e.g. 3G and WLAN interfaces are active both interfaces are optionally provided with their own IP address. Without mobility support an application may use either WLAN interface or 3G but may not switch between interfaces. With mobility support or in other cases, it is possible to offload 3G from running applications and to conduct a handover when WLAN becomes unusable (e.g. leaving hot spot or interferences). For solutions with mobility support the aforementioned mobility solutions are discussed separately.

In accordance with one or more embodiments of the invention, a possibility is provided to enable multiple interfaces for all applications without any terminal modifications or support .

In accordance with one or more embodiments, parallel usage of multiple interfaces is provided while guaranteeing seamless mobility. Embodiments do neither require modifications to the end-system (for downlink traffic) or applications nor the deployment of mobile IP.

Embodiments enable seamless mobility within heterogeneous access technologies, supporting simultaneous usage of multiple interfaces.

One or more embodiments of the invention may e.g. be application agnostic by nature. Agnostic means that a solution is available for any application, or mobility (routing) is hidden from applications, network lower layers are taking care for traffic steering in contrast to alternate link routing, ALR, where the application decides which interface/network should be used. End-system modifications are not necessary but may of course be provided, e.g. for this or other purposes. This is one of the benefits over e.g. application level roaming and mobile IP with multiple care-of addresses which require end-system modifications .

In accordance with one or more embodiments of the invention contrary e.g. to a mechanism of PMIP, i.e. using a forwarding tunnel, no changes at the mobile device side are needed. Embodiments of the invention provided an uncomplicated and effective solution, overcoming problems regarding the use of PMIP in devices. Embodiments may address the downlink data path.

One, more or optionally all embodiments may benefit from the fact that all existing transmission control protocol / internet protocol, TCP/IP, stack implementations will accept and process packets addressed to a locally defined/assigned IP address, even if it is received on a hardware (medium access control, MAC) interface that does not match the IP address. In accordance with one or more embodiments of the invention, the MAC address of the received layer 2 data unit (e.g. Ethernet frame) matches one of the available local interfaces, and the IP address has been locally defined for one of the interfaces. Embodiments may e.g. be implemented with network modifications.

In accordance with one or more embodiments of the invention, this advantageous behaviour is used in unchanged manner, and this characteristic of TCP/IP stack implementations is used to avoid problems when having a situation where a mobile node has two active TCP/IP interfaces (e.g. one via worldwide interoperability for microwave access, WiMAX, and another one via long-term evolution, LTE) .

In accordance with one or more embodiments of the invention control logic, apparatus, means or function are provided to harness this feature to provide true service based mobility in heterogeneous environments. This control logic, apparatus, means or functions may comprise at least one or more of detection of an alternative link, establishment of at least one tunnel, modification of routing tables for complementary use of the two links, and monitoring the relevant access nodes and load, in order to ensure high or the highest quality of experience.

One or more embodiments of the invention enable handsets or terminals, modules, chipsets etc. which are connected to at least two access systems in parallel (such as simultaneously) to redirect services between the interfaces of the handsets or terminals, modules, chipsets etc even in case of legacy handsets, or handsets according to older or actual standards, which are bound to the IP addresses of the individual interfaces .

In accordance with one or more embodiments of the invention, an apparatus, method, system, program etc are configured to enable or provide service selective optimized usage of multiple parallel connected interfaces using mobile or stationary terminals such as e.g. legacy handsets/terminals.

Other objects, features and advantages of the invention will become apparent from the following description of embodiments of the invention.

BRIEF DESCRIPTION OF DRAWINGS Fig. 1 illustrates an example of a system;

Fig. 2 shows embodiments of a system and apparatuses configured in accordance with implementations of the invention;

Fig. 3 and 4 illustrate state machines of control logic parts in accordance with embodiments of the invention;

Fig. 5 shows a further embodiment of a method in accordance with the invention;

Fig. 6 shows an embodiment of a gateway in accordance with the invention;

Fig. 7 shows a further embodiment of a gateway in accordance with the invention.

DESCRIPTION OF EMBODIMENTS

In accordance with one or more embodiments of the invention, a control logic, apparatus, means or function, exploits the fact that IP stacks accept IP packets that are sent to it, even if the MAC address belongs to a different IP address of the same stack.

Advantageously, this provides true service mobility in heterogeneous environments.

In accordance with one or more embodiments of the invention the control logic, means, apparatus or function provides true service based mobility in heterogeneous environments. This control logic etc comprises the detection of the alternative (second) link, establishment of a tunnel (to the last IP endpoint) and modification of routing tables for complementary use of the two links, and monitoring the relevant access nodes and load, in order to ensure high or the highest quality of experience.

In an example embodiment in accordance with the invention, a non-3G, e.g. WLAN, system or other type of access system is considered as a supplementary technology that may be used to offload 3G or to speed up/improve ongoing sessions (e.g. download) . In this and optionally other embodiments, a 3G bearer is always or in general or optionally available as fallback bearer. In the embodiment, the following scenario is used to describe this and optionally other embodiments of the invention .

In this embodiment, a user is first connected to 3G (such as universal mobile telecommunications system, UMTS, high speed packet access, HSPA, long-term evolution, LTE, or others) and has an active best effort bearer. The user is in this example using the best effort data bearer e.g. for voice over IP, and/or downloading of files and/or email synchronisation. While using the data service the user may reach a WLAN hot- spot. After some time at the hot spot, the apparatus such as the terminal or a terminal logic or function, or the user may decide to connect to the WLAN hot spot. After the WLAN connectivity is set-up (e.g. authentication of the user, assignment of IP address) parts or all of the user's data traffic is routed via the WLAN link. When leaving the hot spot area after some time, traffic is routed via 3G again.

In accordance with one or more embodiments of the invention the above scenario is feasible, and as analyzed above, parallel exploitation of the e.g. WLAN connectivity is possible .

Fig. 1 shows a base configuration after a terminal 1 such as a user equipment or stationary or mobile station has attached to WLAN (or other non-3GPP network) . Fig. 1 shows a network operator realm. The terminal 1 comprises an interface 2 such as a 3GPP interface having an assigned IP address A, and an interface 3 such as a WLAN interface having an assigned IP address B. Packets destined for IP address A are sent via a traffic path 6 and a 3G network 4.

The traffic path or flow 6 is sent via a packet data network gateway 8 and a packet network 19 such as the internet to and from a terminal 20 such as a called party (B-party, e.g. a voice over internet protocol call) and / or a server 21 or other type of apparatus such as a download server.

In order to change this default behaviour, in accordance with one or more embodiments of the invention one or more of the following network side modifications may be implemented, as shown in the embodiment of Fig. 2.

1. ) The packet data network gateway, PDN-GW, 8 and a packet data gateway, PDG, 13 are equipped with tunnel functionality so as to establish a tunnel 17 (e.g. IP, layer 2) between the gateways 8, 13, the tunnel may e.g. be an IP-in-IP tunnel; 2a.) the packet data network gateway, PDN-GW, 8 is equipped with a control module 11 for a routing control or engine 10; 2b.) the packet data gateway 13 is equipped with a control module 15 for a routing engine;

3.) the packet data network gateway, PDN-GW, 8 is provided with a decision logic 9 that is responsible for flow mapping; the decision logic 9 may be connected to the monitoring functions 5, 14 via links 7, 16, or may receive information from or send information to the monitoring components 5, 14; 4.) the packet data gateway 13 is enhanced by a monitoring functionality 14 to observe WLAN connectivity (feedback loop or transport path 16 to decision logic 9 for informing the decision logic on the monitoring result) ;

5.) the 3G network 4 is equipped with a monitoring function or device 5 which can report the monitored 3G flow or connectivity to the decision logic 9; 6.) a control plane is provided.

Note that the term packet data gateway or PDG is used in the specification, claims and drawings to optionally or generally refer to the last layer 3 hop/router before the terminal 1. PDG is only used in the case of non-trusted non-3G access but embodiments of the invention are also valid and applicable for trusted non-3G access. For this case the term PDG simply may be changed e.g. to access router (or mobility access gateway, MAG, in PMIP terminology) .

In the embodiments of Fig. 2 or 5, the remainder is structured according to the functional logic behind embodiments of the invention, comprising one or more or all of detection of alternative connectivity, control flow, flow distribution, and monitoring.

The traffic path or flow 6 provides signalling, information and/or traffic flow to or from or between interface 2 and e.g. called party or terminal 20 via network 4, packet data network gateway 8 and packet network 19. The terminal 20 may e.g. be called party (B-party, e.g. a voice over internet protocol call) . The traffic path or flow 12 provides signalling, information and/or traffic flow to or from or between interface 3 and e.g. server or terminal 21 via network gateway 13, packet data network gateway 8 and packet network 19. The server 21 may e.g. be a download server or other type of apparatus or end point.

Fig. 3 illustrates a state machine of control logic part within gateway 8, e.g. PDN-GW. In state 31 an alternative is available but not useable according to measurements. In state 32, no alternative connection is available. In state 33, an alternative connection is available. If so, in state 34, an alternative connection is set up (tunnel+routing) . The state machine may change between the states as indicated by the arrows .

Fig. 4 illustrates a state machine of control logic part within gateway 13, e.g. PDG. In state 41 a connection is established and may be suspended. In state 42 a user x is not connected. In state 43 the user x is connected to a non-3G network. In state 44 a tunnel or routing is set up. In state 45 the connection is established or active. The state machine may change between the states as indicated by the arrows.

In the following at least one embodiment is described with regard to a feature of detection of alternative connectivity.

In this example embodiment case, the starting point is a terminal, e.g. terminal 1, with an active PDP context, entering a non-3G, e.g. WLAN, coverage area (non-roaming) .

If terminal 1 enters an optionally preferred non-3G coverage area (e.g. information provided by 3GPP access network discovery and selection function, ANDSF) , it starts to register using the normal procedure. The set-up of the alternative path is triggered after registration is complete.

It is to note that different cases exist for the sub- procedure of attachment to the non-3GPP access.

For WLAN: The first one is known as the integrated, or "I- WLAN" access, described in 3GPP TS 23.234 and 22.234. Here, the WLAN access user is authenticated via the 3G operator' s infrastructure, such as Radius, remote authentication dial- in user service, and/or home location register, HLR, and also the IP address is provided/configured by the 3G operator.

For worldwide interoperability of microwave access, WiMAX: WiMAX access is not fully specified in the scope of 3GPP 23.402, the data paths of 3G (incl. SAE) and WiMAX can be assumed to join in the packet gateway, PGW, network element. Therefore, the tunnel provided for one more or all embodiments of the invention may be set up from the PGW to the WiMAX system, more precisely to the WiMAX network element that is closest to the mobile device (terminal 1 in the embodiment of Fig. 2, first IP hop) . Authentication and IP address configuration can be assumed to be synchronized within the operator's domain.

Another case consists of a non-integrated procedure for authentication and IP address configuration which can be different in deployments. The integrated solutions of Fig. 2 or the above described WLAN and WiMAX cases may e.g. be used in cases where the operator owns the non-3GPP access and follows the I-WLAN procedures.

Summarizing, the above described embodiment cases for WLAN and WiMAX, as well as other access types, allow for detection of multiple parallel access (even WLAN, WiMAX and 3G simultaneously) by a subscriber device by querying the operator's Radius and/or HLR data bases, using the subscriber's ID or other unique credentials as the key.

A feature of one or more embodiments regarding this part of the overall process is to determine the last IP hop, i.e. the tunnel endpoint closest to the mobile device e.g. 1, as this node, e.g. 13, is in direct connection with the mobile device via its interface ID.

In accordance with one or more embodiments of the invention there is used a similar signal path used for the transmission of traffic/quality measurement data (monitoring components 5, 14 in Fig. 2) for sending the IP address of the access node, e.g.13 to which the mobile device e.g. 1 is directly connected to the other tunnel end point of tunnel 17 in the PDN-GW 8. In some embodiments the PDN-GW 8 knows this IP address; if not, it is easily detectable using, for example, the traceroute command, which returns all layer 3 hops all the way down to the mobile device 1. 3GPP TS 23.402 separates non-3GPP access into "trusted" and "untrusted" cases. In principle, this means that some details can be different such as authentication and IP address provisioning, but that does not change the basic concept of one or more embodiments of the invention.

Fig. 5 shows an embodiment of a message sequence chart or method of tunnel creation (control plane) .

As shown in the embodiment of Fig. 5, as to the control flow, in process or function Sl, after registration is complete, gateway, PDG, 13 contacts PDN-GW 8 to prepare simultaneous usage of interfaces 2, 3. For this purpose the gateway 13 may send a message S2 such as a modify_routing_request to the PDN-GW 8 including e.g. subscriber identifier, reference number and preferred tunnelling protocol (e.g. L2TP, IP-in- IP) . In process or function S3, the gateway PDN-GW 8 checks subscriber^ rights (e.g. HLR) and if positive, creates local tunnel endpoint and modifies local routing. Thus in process or function S3 the gateway 8 checks whether the subscriber is allowed to use multiple interfaces. The gateway 8 may then start with the creation of tunnel 17 by conducting local configuration and sending a respective command S4 e.g. create_tunnel (reference_number, tunnelling protocol, 3G IP) or modify_routing_failed (reference_number, reason) . The gateway 13 creates a tunnel end-point. The gateway 8 and/ or 13 modify local routing table to forward packets with destination address of the 3G network 4 such as the destination address 3G_IP to mobile terminal 1 using non-3G access 13. If successful the gateway 13 responds with a confirmation S5 such as tunnel_established (reference_id) , else with a rejection such as tunnel_failed (reference_id, reason) .

In process or function S6, when tunnel 17 is established, the gateway PDN-GW 8 loads traffic filters from a profile or subscriber data base and redirects all packets to 3G_IP or IP address A to traffic filters. Traffic filter forwards packets either to the tunnel 17 or via 3G network 4, depending e.g. also on the received monitoring data and according decisions (see Fig. 2.

As to flow Distribution, after the tunnel 17 is established and the routing tables are modified the PDN-GW 8 can route packets to user x of terminal 1 either via 3G or the non-3G access. The scheduling may depend on local policies and can for example implement the following behaviour: all packets are sent via non-3G; all TCP packets with segment size equal or approximately equal to MTU, or a defined fraction such as e.g. one half or two thirds of MTU, or == MTU, are sent via non-3G, MTU stands for maximum transfer unit; normally TCP, transmission control protocol is used to transfer larger blocks of data (e.g. web pages, file transfer) and hence it tries to send large packets matching the packet size allowed by the underlying networks. Such packets may belong to best effort traffic and hence could be offloaded to e.g. WLANs; the term MTU denotes the maximum size of a packet (for framing purposes) . If, for example, a lot of big packets are discovered, this means usually that someone is downloading a large file or does streaming, so this can be used as an indicator to use a certain access type; packets with certain IP 5-tuple are sent via non-3G; packets with certain DiffServ Codeppoint are sent via non-3G; mechanisms, e.g. statistic based traffic analysis, or port based can be used to classify traffic; traffic that meets certain conditions can be sent via non-3G. The mechanisms can ce provided by or implemented as one or more packet switched core elements such as gateway general packet radio service support node, GGSN, plus additional services for packet transfer, such as flow handling.

As to monitoring, an advantage of one or more embodiments of the invention is that the 3G path is still available, meaning a fallback to the default path is fast. Ensuring this behaviour guarantees that subscribers will not experience poor quality of experience although they might be using a technology not supporting any QoS. However to use the fast- fall back monitoring mechanism are provided in one or more embodiments. These monitoring mechanisms are not mandatory for the general deployment but may improve performance. The packet data gateway may be responsible to monitor the link quality (e.g. number of buffered packets, number of retransmissions) if needed/supported by other network elements. If the quality falls below a certain threshold (multiple levels are possible) a message is sent to the PDN- GW 8. Based on the level the PDN-GW 8 decides which packets to send via non-3G and 3G.

An alternative implementation of the invention is based on so-called "host based routing". Here, the network management system modifies the routing tables on all routers on the path from PDN-GW 8 to the last hop (PDG 13) to ensure that packets destined to IP Addr A are forwarded towards IP Addr B via PDG 13. One possibility to modify all routers on the path 12 is to use a new variant of the NSIS protocol family. Another alternative may be used if the transport network between PDN-GW and access router is based on optical technologies or other L2 approaches. In this case only the routing logic in the PDN-GW 8 and the access router needs to be reconfigured according to traffic distribution strategy.

Note that the above alternative implementations all benefit from the same technical base concept of embodiments of the invention - IP packets are generally accepted by an IP stack, even if they arrive on a host interface that is bound to a different IP address.

As to support for uplink (terminal generated) traffic, embodiments of the invention described up to this point support download traffic direction only. In order to support also traffic generated by the end-terminal 1 modifications to the terminal 1 may be provided. Packets generated by the terminal 1 (e.g. applications on the terminal) use the IP address A (in the example) as source address otherwise the peer entity would not accept incoming packets and applications started while the terminal uses non-3G access technology would be dropped when non-3G coverage is left. To use IP Addr A on interface B two problems are solved. First, depending on the implementation of the terminals protocol stack, packets with source IP address A are bound to interface A meaning that they are routed via interface A. To change this the network implementation is changed. Second, the access router normally would not accept an packet with source address A since it is topologically not correct. However, as in the embodiment case the access router is already aware of IP address A this policy can be relaxed.

A check of correct functioning is possible without problems: E.g. any IP network sniffer on a mobile device may show that packets with the ,,wrong" MAC address appear on one of the attached network interfaces.

In case a third party offers the service, too, at least one mobile operator may establish a tunnel to this third party. Embodiments have support from the network, i.e. having the network accept a topologically incorrect address, or creation of a tunnel (see above) .

Embodiments enable mobility between heterogeneous access networks without requiring PMIP or many client side modifications. Our solution could be a way out. Moreover currently TMO US is interested in a Smart Connectivity trial and we (NSN - project MHN) is preparing project proposal. Embodiments of the invention may comprise similar functionality (e.g. tunnel set-up between access router and PDN-GW) as PMIP. Alternatively it is possible to reuse PMIP signalling partially (e,g to create the tunnel between PDN-GW and access router) . Embodiments enable complementary use of heterogeneous access networks: The operator can off-load data and save money, while the end user can have increased performance, justifying slightly higher costs, or increasing service acceptance.

Fig. 6 illustrates an embodiment of a gateway of a packet data network such as gateway 8. The gateway 8 may be configured to implement some of the above described processes or functions relating to the gateway 8, and comprises a sender and receiver or transceiver 81 for receiving traffic, signalling, data etc, a processor 82 for controlling part or all of the gateway 8, a checker part 83, device, means or function configured to check subscriber rights , a tunnel creation part 84, device or function for creating a tunnel, a router modifier part 85, device or function for modifying the routing, and a traffic filtering and rerouting part 86, device or function.

Fig. 7 illustrates an embodiment of a gateway such as gateway 13. The gateway 13 may be configured to implement some of the above described processes or functions relating to the gateway 13, and comprises a sender and receiver or transceiver 131 for receiving traffic, signalling, data etc, a processor 132 for controlling part or all of the gateway 13, a registration part 133, device, means or function for registering, a preparation part 134, device or function for using, or preparing to use two or more interfaces, and a tunnel creating part 135, device or function for creating a tunnel or tunnel endpoint to the gateway 8.

The network may comprise one or more of the apparatuses or gateways as mentioned above. The network may comprise any appropriate architecture such as an evolved packet service, EPS architecture, or may comprise at least one of a serving general packet radio service support node, SGSN, a mobility management entity, MME, or gateways.

In accordance with one or more of the embodiments of the invention, a computer program product is provided which comprise code means configured to carry out or implement, when run on a processor, one or more or all of the above described features or processes. The computer program product may e.g. be embodied on a computer-readable medium.

A PDN gateway (P-GW or PGW) may e.g., according to an embodiment, be a gateway general packet radio service, GPRS, support node, GGSN.

For the purpose of the present invention as described herein above, it should be noted that any access or network technology may be used which may be any technology by means of which a user equipment can access a network. The network may be any device, unit or means by which a mobile or stationary entity or other user equipment may connect to and/or utilize services offered by the network. Such services may include, among others, data and/or (audio-) visual communication, data download etc.

Generally, the present invention is also applicable in those network/terminal environments relying on a data packet based transmission scheme according to which data are transmitted in data packets and which are for example based on the Internet Protocol IP. The present invention is, however, not limited thereto, and any other present or future IP or mobile IP version, or, more generally, a protocol following similar principles is also applicable. The user equipment entity may be any device, unit or means by which a system user may experience services from a network. The sequence of method steps described above or shown in the drawings can be implemented in any other sequence arbitrarily deviating from the above described or shown sequence of steps. Further, the method, apparatuses and devices, may include only one, more or all of the features described above or shown in the drawings, in any arbitrary combination. The method steps may be implemented as software code portions and be run using a processor at a network element or terminal, can be software code independent, or can be specified using any known or future developed programming language as long as the functionality defined by the method steps is preserved. Generally, any method step is suitable to be implemented as software or by hardware without changing the idea of the present invention in terms of the functionality implemented. Devices, apparatus, units, or means, and/or method steps may be implemented as hardware components of a stationary or mobile station, or a terminal, or a network element, or part, or chipset, or module thereof, which part, or chipset, or module e.g. be used for an apparatus; may be hardware independent; and may be implemented using any known or future developed hardware technology or any hybrids of these, such as MOS (Metal Oxide Semiconductor), CMOS (Complementary MOS), BiMOS (Bipolar MOS), BiCMOS (Bipolar CMOS), ECL (Emitter Coupled Logic), TTL (Transistor-Transistor Logic), etc., using for example ASIC (Application Specific IC (Integrated Circuit) ) components, FPGA (Field-programmable Gate Arrays) components, CPLD (Complex Programmable Logic Device) components or DSP (Digital Signal Processor) components. Devices, apparatus, units or means (e.g. User equipment, CSCF) can be implemented as individual devices, units, means, chipsets, modules, or part of devices, and may also be implemented in a distributed fashion throughout a system, as long as the functionality of the device, unit or means is preserved.

Claims

1. Apparatus configured to detect an alternative link to a terminal, to establish a tunnel for at least part of the alternative link, and/or to modify at least one routing table for use of the alternative link and at least one further link.

2. Apparatus according to claim 1 wherein the apparatus is at least one of an access router, a gateway, a packet data gateway, a packet data network gateway.

3. Apparatus according to claim 1 or 2, configured to establish the tunnel between a packet data network gateway and an access router or gateway, or for a layer 3 hop, or for the last layer 3 hop before the terminal, or to a tunnel endpoint closest to the terminal.

4. Apparatus according to any one of the preceding claims, comprising at least one or more of the following in any arbitrary combination: a gateway, packet data gateway, access router or packet data network gateway equipped with tunnel functionality e.g. IP, layer 2, a gateway, packet data gateway, access router or packet data network gateway equipped with control module for routing engine, a gateway, packet data gateway, access router or packet data network gateway equipped with decision logic or function responsible for flow mapping, a decision logic or function responsible for flow mapping connected to monitoring parts or functions of a gateway to a data or internet protocol network, a gateway, packet data gateway, access router or packet data network gateway equipped with monitoring functionality to observe connectivity, a gateway, packet data gateway, access router or packet data network gateway equipped with feedback loop to decision logic, a control plane , configured to monitor at least one access node and load in case a mobile node has two or more active interfaces.

5. Apparatus according to any one of the preceding claims, configured to at least one or more of the following in any arbitrary combination: detection of two or more parallel accesses, optionally by a subscriber device determine a last internet protocol hop or a tunnel endpoint closest to a mobile device, or a node in direct connection with the mobile device, use a signal path for sending the IP address of the access node to which the mobile device is directly connected to an other tunnel end point in a gateway or packet data network gateway, use a command returning layer 3 hops down to the mobile device.

6. Apparatus according to any one of the preceding claims, configured to at least one or more of the following in any arbitrary combination: register, contact, or initiate to contact, a packet data network gateway to prepare simultaneous usage of interface, send a modifying request to the gateway optionally including at least one of subscriber identifier, reference number and preferred tunnelling protocol, check whether a subscriber is allowed to use multiple interfaces, create a tunnel or tunnel end-point, modify a local routing table to forward packets with destination address of one network to mobile terminal using another network access, load one or more traffic filters from a profile and redirect packets comprising an address of the one network to traffic filters, traffic filter forwards packets either to the tunnel or to the one network.

7. Apparatus according to any one of the preceding claims, configured to at least one or more of the following in any arbitrary combination: provide a flow distribution of one or more flows to a terminal, route one or more packets to a user via a first access or 3G access or a second access or non-3G access in accordance with a scheduling, the scheduling depending on local policies, the scheduling implementing one or more of the following : send all packets via the second access, send all packets such as transmission control protocol packets with a certain segment size or a segment size lower or higher than a threshold via the second access, send packets with certain internet protocol 5-tuple via the second access, send packets with certain DiffServ codepoint via the second access.

8. Apparatus according to any one of the preceding claims, configured to at least one or more of the following in any arbitrary combination: keep available a path as a second or default path, provide monitoring, monitor at least one or more of a link quality, a number of buffered packets, a number of retransmissions, send a message to a packet data network gateway if the quality falls below one or more threshold levels, decide based on the quality level on the routing of packets via a first or second access such as 3G and non-3G, provide a host based routing wherein a network management system modifies routing tables on all routers on a path from a packet data network gateway to a last hop or packet data gateway or access router to forward packets destined to an interface of a mobile terminal towards another interface of the mobile terminal, provide support for uplink or terminal generated traffic, use an address of an alternative link on an interface of another link.

9. Network, comprising one or more apparatuses according to any one of the preceding claims.

10. A method, comprising detecting an alternative link to a terminal, establishing a tunnel for at least part of the alternative link, and/or modifying at least one routing table for use of the alternative link and at least one further link.

11. Method according to claim 10, comprising establishing the tunnel between a packet data network gateway and an access router or gateway, or for a layer 3 hop, or for the last layer 3 hop before the terminal, or to a tunnel endpoint closest to the terminal.

12. Method according to claim 10 or 11, comprising at least one or more of the following in any arbitrary combination : tunnel functionality for a gateway, packet data gateway, access router or packet data network gateway, a control function for a routing engine, a decision function responsible for flow mapping, a decision function responsible for flow mapping connected to monitoring parts or functions of a gateway to a data or internet protocol network, a monitoring functionality to observe connectivity, a feedback loop to decision logic, a control plane, monitoring at least one access node and load in case a mobile node has two or more active interfaces.

13. Method according to any one of claims 10 to 12, comprising at least one or more of the following in any arbitrary combination: detecting of two or more parallel accesses, optionally by a subscriber device determining a last internet protocol hop or a tunnel endpoint closest to a mobile device, or a node in direct connection with the mobile device, using a signal path for sending the IP address of the access node to which the mobile device is directly connected to an other tunnel end point in a gateway or packet data network gateway, using a command returning layer 3 hops down to the mobile device register, contact a packet data network gateway to prepare simultaneous usage of interface, send a modifying request to a gateway optionally including at least one of subscriber identifier, reference number and preferred tunnelling protocol, check whether a subscriber is allowed to use multiple interfaces, create a tunnel or tunnel end-point, modify a local routing table to forward packets with destination address of one network to mobile terminal using another network access, load one or more traffic filters from a profile and redirect packets comprising an address of the one network to traffic filters, traffic filter forwards packets either to the tunnel or to the one network, provide a flow distribution of one or more flows to a terminal, route one or more packets to a user via a first access or 3G access or a second access or non-3G access in accordance with a scheduling, the scheduling depends on local policies, the scheduling implements one or more of the following: send all packets via the second access, send all packets such as transmission control protocol packets with a certain segment size or a segment size lower or higher than a threshold via the second access, send packets with certain internet protocol 5-tuple via the second access, send packets with certain DiffServ Codepoint via the second access, keep available a path as a second or default path, provide monitoring, monitor at least one or more of a link quality, a number of buffered packets, a number of retransmissions, send a message to a packet data network gateway if the quality falls below one or more threshold levels, decide based on the quality level on the routing of packets via a first or second access such as 3G and non-3G, provide a host based routing wherein a network management system modifies routing tables on all routers on a path from a packet data network gateway to a last hop or packet data gateway or access router to forward packets destined to an interface of a mobile terminal towards another interface of the mobile terminal, provide support for uplink or terminal generated traffic, use an address of an alternative link on an interface of another link.

14. Computer program product, comprising code means configured to carry out or implement, when run on a processor, a method in accordance with any one of claims 10 to 13.

15. Computer program product according to claim 14, embodied on a computer-readable medium.