Method and system for adding IP routes to a routing mobile terminal with 3G messages

The invention is directed to enabling an serving node and a gateway node to be informed of a new route for a new node or sub-network that has become active behind a Mobile Terminal that can also act as a router. When IP level route injection occurs at the Mobile Terminal, a Modify session profile message causes insertion of a new IP address or prefix at a gateway node related to the new route. Also, the gateway node will update the serving node and the Mobile Terminal with information related to the new route or a proposed new route. The Mobile Terminal and the gateway node can share routing information over a dynamic routing protocol. Additionally, the Mobile Terminal and the gateway node can configure static routing information on routes towards each other. The new route can be added with 24.008 and/or GTP messages when initiated on the Mobile Terminal side for either the dynamic or static case.

FIELD OF THE INVENTION

The present invention relates to IP mobility for mobile nodes, and more particularly to enabling IP routes to be added to a routing mobile node.

BACKGROUND OF THE INVENTION

This invention considers the problem of enabling a Mobile Terminal to function as an IP router on a Third Generation Partnership Project (3GPP) wireless network. Currently, a Mobile Terminal is standardized to connect to a 3GPP network as purely a terminal, which means on the Internet Protocol (IP) level the Mobile Terminal is assumed to support only IP/IPv6 host functionalities. This means that router functionalities, such as those defined in RFC 1812 for IPv4, or scattered into the RFCs 2460 to 2473 for IPv6, typically cannot be supported on or behind current 3GPP Mobile Terminals.

Mobile Terminal functionalities, as specified in 3GPP TS 27.060 V4.0.0 (2001-03) document, indicate that a Mobile Terminal is designed to function on a high level in a similar manner as a modem, which establishes a connection with a network access server (NAS). This design in the current specification enables IP host operation only rather than operation over a point-to-point link connected to an IP router. One issue is that the Gateway General Packet Radio Service (GPRS) Support Node (GGSN) assigns individual addresses for the Mobile Terminal in an activated Packet Data Protocol (PDP) Context, and does not forward traffic for other IP addresses via those addresses. Thus, a Mobile Terminal may not configure addresses into itself if there are other addresses in it or behind it, e.g. in a personal area network (PAN) connected to other networks via a Mobile Terminal. Also, there is a requirement for legal interception of traffic by the Mobile Terminal, in addition to the IPv6 routing requirements.

SUMMARY OF THE INVENTION

In accordance with the invention, a method is directed to adding a new route for a node disposed behind a mobile terminal that can operable as a router for the node disposed behind the Mobile Terminal. In response to receiving the new route for the node, the Mobile Terminal can send an Activate session profile message to a gateway node and send a Modify session profile message along with the new route to a serving node. The serving node records the new route and updates the gateway node with the new route. The gateway node can also determine each new route that is updateable to a routing table. Each updateable new route is added to the routing table and an Update session profile message along with the new route is sent to the serving node and the Mobile Terminal. Also, the gateway node can determine each new route that is un-updateable to the routing table. If the gateway node is unable to propose another new route that is updateable to the routing table for the node, the gateway node can send an error message to the serving node and the Mobile Terminal. Additionally, if the gateway node does propose the other new route that is updateable to the routing table for the node, the gateway node can send the other new route along with the Update session profile message to the serving node and the Mobile Terminal where they are employed to update the serving node and the Mobile Terminal with the other new route.

In accordance with another aspect of the invention, the node represents at least one sub-network.

In accordance with still another aspect of the invention, in response to receiving a request to delete a route for the node disposed behind the Mobile Terminal, the Mobile Terminal sends another activate session profile message to the gateway node and sends another Modify session profile message along with the deleted route to the serving node. The serving node records the deletion of the route and updates the gateway node with the deletion of the route. Additionally, the gateway node is employed to delete the route from the routing table and provide another Update session profile message to the serving node and the Mobile Terminal along with the deleted route.

In accordance with yet another aspect of the invention, the gateway node is a GGSN, the serving node is a SGSN and the session profile is a PDP context.

In accordance with still yet another aspect of the invention, an API from an IP routing engine of the Mobile Terminal is employed for GPRS signaling. Manipulation of at least one of a kernel route and an alias address through an IP routing socket is employed to cause the triggering of a corresponding Modify PDP context message.

In accordance with a further aspect of the invention, the Mobile Terminal and the gateway node share routing information over a dynamic routing protocol.

In accordance with yet a further aspect of the invention, the Mobile Terminal and the gateway node configure static routing information on at least one route towards each other.

In accordance with yet another aspect of the invention, an apparatus and system may be employed to practice substantially the same actions discussed above for the method.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Throughout the specification and claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise. The term “node” refers to a network element that monitors a load for a link within a path. The term “link load” refers to the load associated with the node. The term “flow” means a flow of IP packets. The term support node refers to both “GGSN” and “SGSN” nodes. The term “user” refers to any person or customer such as a business or organization that employs a mobile device to communicate or access resources over a mobile network. The term “operator” refers to any technician or organization that maintains or services an IP packet based network. The term “identifier” includes an MSISDN number, an IP address, or any other information that relates to the location or identity of the user.

The term “router” refers to a dedicated network element that receives IP packets and forwards them to their destination. In particular, a router is used to extend or segment networks by forwarding IP packets from one logical network to another. A router typically operates at layer3and below of the Open Systems Interconnection (OSI) reference model for networking. However, some routers can provide additional functionality that operates above layer3of the OSI reference model.

Generally, a router is aware of multiple paths that a received IP packet can take to its final destination. Based on the logical address included in a received IP packet, a router will forward the IP packet along an optimal path towards its final destination. Typically, a router contains internal tables of information called routing tables that keep track of all known network addresses and possible paths throughout the internetwork, along with the cost of reaching each logical network. A router optimally routes IP packets based on the available paths and their costs, thus taking advantage of redundant paths that can exist in a mesh topology network. Some routers have static routing tables that must be manually configured with all network addresses and paths in the internetwork. Other routers are capable of automatically/dynamically creating their own routing tables by listening to network traffic.

The term “Mobile Terminal” and “Mobile Node” are used interchangeably, and refer to a wireless device that can change its point of attachment from one network or sub-network to another. A mobile terminal/node may change its location without losing connectivity and without changing its IP address; it may continue to communicate with other nodes at any location using its (constant) IP address, assuming link-layer connectivity to a point of attachment is available. A mobile node can change its point of attachment from one link to another, while still being reachable via its constant IP address.

Referring to the drawings, like numbers indicate like parts throughout the views. Additionally, a reference to the singular includes a reference to the plural unless otherwise stated or is inconsistent with the disclosure herein.

The invention provides a mechanism for describing a new available route behind a mobile terminal for a packet switched cellular network. IP-level forwarding through a gateway node is possible to and from a new route, which may be a new host-based route to a second address, or a network route to a prefix on a link “behind” the Mobile Terminal, e.g. in another interface on the Mobile Terminal. The destination of the route can be in the Mobile Terminal or behind it in another node, or it can be a subnetwork route pointing behind the Mobile Terminal. Solving this problem enables considering the link between a gateway node and the Mobile Terminal as any IP-enabled point-to-point link between two IP-level routers. In the past, it was difficult to have more than one address in a session profile, e.g., a Packet Data Protocol (PDP) context, that was not originally designed for the Mobile Terminal to operate as a router.

The invention enables sub-networks operating behind a Mobile Terminal. This feature makes the link layer look like a traditional link-layer under IP. Also, it is a prerequisite for calling the IP connectivity generic and not a subset of full IP connectivity. Connecting sub-networks behind the Mobile Terminal makes wireless access technology substantially similar to other IP technologies such as Digital Subscriber Lines (DSL), Integrated Services Digital Network (ISDN), or Local Area Network (LAN), from what IP connectivity features can be supported. Also, the invention supports the legal interception of traffic by the Mobile Terminal and makes a Mobile Terminal operating as a router responsible for the packet traffic forwarded through it.

Additionally, the invention enables heterogeneous devices behind the Mobile Terminal to access the network without them having to have the same link layer as the Mobile Terminal. This feature can be seen as an advantage for the end user and less so when business models wish to end user operations. Although the examples below mostly describe the operation of the invention in a GPRS environment, it is understood that the invention can be employed with any packet switched cellular network.

Illustrative Operating Environment

With reference toFIG. 1, an exemplary mobile IP network in which the invention may operate is illustrated. As shown in the figure, mobile IP network100includes mobile terminal (MT)105, radio access network (RAN)110, SGSN115, core network120, base stations123A-C, routers125A-C, optional bandwidth broker (BB)300, GGSNs135A-B, data network140, and data network145.

The connections and operation for mobile IP network100will now be described. Mobile terminal105is coupled to radio access network (RAN)110. Generally, mobile terminal105may include any device capable of connecting to a wireless network such as radio access network110. Such devices include cellular telephones, smart phones, pagers, radio frequency (RF) devices, infrared (IR) devices, integrated devices combining one or more of the preceding devices, and the like. Mobile terminal105may also include other devices that have a wireless interface such as Personal Digital Assistants (PDAs), handheld computers, personal computers, multiprocessor systems, microprocessor-based or programmable consumer electronics, network PCs, wearable computers, and the like.

Mobile Terminal105manages access and routes message to sub-network102, which includes several wireless devices104A-Dthat are in communication with each other and the mobile terminal. In one embodiment, the sub-network may employ the Bluetooth wireless protocol.

Radio Access Network (RAN)110manages the radio resources and provides the user with a mechanism to access core network120. Radio access network110transports information to and from devices capable of wireless communication, such as mobile terminal105. Radio access network110may include both wireless and wired telecommunication components. For example, radio access network110may include a cellular tower and/or base stations that are linked to a wired telecommunication network. Typically, the cellular tower carries wireless communication to and from cell phones, pagers, and other wireless devices, and the wired telecommunication network carries communication to regular phones, long-distance communication links, and the like. As shown in the figure, RAN110includes base stations123A-C.

According to one embodiment of the invention, routers125A-Cmay calculate their own link loads as well as process link loads relating to other nodes on the network. The routers may send a warning message to other routers within the network when its link load exceeds a configurable threshold. When there is at least one link load within each available path from a source to a destination for a new flow that is above the configurable threshold, the new flow attempting to enter the network is rejected.

In yet another embodiment, one or more of base stations123A-Cmay have router functionality. Although not shown, Radio Network Controllers (RNCs) may also include router functionality.

Some nodes may be General Packet Radio Service (GPRS) nodes. For example, Serving GPRS Support Node (SGSN)115may send and receive data from mobile stations, such as mobile terminal105, over RAN110. SGSN115also maintains location information relating to MS105. SGSN115communicates between mobile terminal105and Gateway GPRS Support Node (GGSN)s135A-Bthrough core network120. According to one embodiment of the invention, BB300communicates with RAN110and core network120.

Core network120is an IP packet based backbone network that includes routers, such as routers125D-F, to connect the support nodes in the network. Routers are intermediary devices on a communications network that expedite message delivery. On a single network linking many computers through a mesh of possible connections, a router receives transmitted messages and forwards them to their correct destinations over available routes. Routers may be a simple computing device or a complex computing device. For example, a router may be a computer including memory, processors, and network interface units.

GGSNs135A-Bare coupled to core network120through routers125A-Cand act as wireless gateways to data networks, such as network140and network145. Networks140and145may be the public Internet or a private data network. GGSNs135A-Ballow mobile terminal105to access network140and network145.

The operator may set threshold levels to determine whether or not to accept a new flow based on different service classes for a particular user or group of users. As mentioned above, the routers, or some other dedicated network element may be used for this purpose. For example, conversational traffic from user group A may be carried with an Expedited Forwarding (EF) class would have one threshold level, whereas conversational traffic from user group B carried with an Assured Forwarding (AF) class would have a different service level. A user of mobile terminal105may be differentiated into one of these user groups by the user Mobile Station Integrated Services Digital Network (MSISDN) number that is known to both the SGSN and the GGSN support nodes.

Furthermore, computers, and other related electronic devices may be connected to network140and network145. The public Internet itself may be formed from a vast number of such interconnected networks, computers, and routers. Mobile IP network100may include many more components than those shown inFIG. 1. However, the components shown are sufficient to disclose an illustrative embodiment for practicing the present invention.

The media used to transmit information in the communication links as described above illustrate one type of computer-readable media, namely communication media. Generally, computer-readable media includes any media that can be accessed by a computing device. Communication media typically embodies computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, communication media includes wired media such as twisted pair, coaxial cable, fiber optics, wave guides, and other wired media and wireless media such as acoustic, RF, infrared, and other wireless media.

FIG. 2shows another exemplary system in which the invention operates in which a number of local area networks (“LANs”)220a-dand wide area network (“WAN”)230interconnected by routers210. On an interconnected set of LANs—including those based on differing architectures and protocols—, a router acts as a link between LANs, enabling messages to be sent from one to another.

Communication links within LANs typically include twisted wire pair, fiber optics, or coaxial cable, while communication links between networks may utilize analog telephone lines, full or fractional dedicated digital lines including T1, T2, T3, and T4, Integrated Services Digital Networks (ISDNs), Digital Subscriber Lines (DSLs), wireless links, or other communications links.

Furthermore, computers, such as remote computer240, and other related electronic devices can be remotely connected to either LANs220a-dor WAN230via a modem and temporary telephone link. The number of WANs, LANs, and routers inFIG. 2may be increased or decreased without departing from the spirit or scope of this invention. As such, the Internet itself may be formed from a vast number of such interconnected networks, computers, and routers and that an embodiment of the invention could be practiced over the Internet without departing from the spirit and scope of the invention.

Illustrative Methods

In a packet switched cellular network, this invention enables a serving node to be aware of a new node or subnetwork that has become active behind a Mobile Terminal that acts as a router, when IP-level route injection occurs at the Mobile Terminal.

In an exemplary GPRS network, as a result of an IP route or IP address injection into a Mobile Terminal, a signaling message is provided from the Mobile Terminal with a request for modifying the PDP Context which causes insertion of a new address or prefix to a GGSN when it learns of routes that have been inserted into the Mobile Terminal and where the destinations are on the Mobile Terminal side. After learning of a new route, the GGSN checks whether the requested address is in its pool of addresses and prefixes, and then updates the new route to the serving node, i.e., the SGSN. Also, for optional optimization, at the IP layer, a corresponding IP route may also get injected to the GGSN after it gets injected to the Mobile Terminal.

Learning of a route can be classified into two categories, dynamic and static. A Mobile Terminal and a gateway node such as a GGSN can share routing information over a dynamic routing protocol. Also, the Mobile Terminal and the GGSN can configure static routing information on routes towards each other. In one embodiment, a route can be added with 24.008 and GTP messages, when initiated on the Mobile Terminal side. It also applies to both static and dynamic route addition.

To exchange data packets with an external packet data network after successful attachment to a GPRS network, a Mobile Terminal applies for one or more addresses used in an external packet data network, e.g., an IP address. This address is called a PDP address (Packet Data Protocol address). Also, a PDP context can be understood as a profile that describes characteristics of each session. The PDP context can contain the PDP type (e.g., IPv4, IPv6, etc.), the PDP address assigned to the mobile terminal (e.g., 129.187.222.10), the requested quality of service, and the address of a GGSN that serves as the access point to the external packet data network. This PDP context is typically stored in the Mobile Terminal, the SGSN, and the GGSN. With an active PDP context, the Mobile Terminal becomes “visible” to an external packet data network and is able to send and receive data packets. The mapping between the PDP address and an international mobile subscriber identity (IMSI), enables the GGSN to transfer data packets between the external packet data network and a Mobile Terminal. In certain circumstances, a user may have several simultaneous PDP contexts active at a given time.

Additionally, besides phone numbers and subscriber and equipment identifiers, other identifiers are employed for the management of subscriber mobility and for addressing other network elements. In particular, the international mobile station equipment identity (IMEI) uniquely identifies a mobile terminal internationally. It operates as kind of a serial number. The IMEI is allocated by an equipment manufacturer and registered by the network operator. Also, each registered user is uniquely identified by their international mobile subscriber identity (IMSI), which is stored in a subscriber identity module (SIM) card. For operating on a GPRS network, a Mobile Terminal typically requires a SIM with a valid IMSI to be inserted into equipment with a valid IMEI.

InFIG. 3, the case of static route addition in the Mobile Terminal is illustrated for an exemplary GPRS network. A presumption is that the Mobile Terminal first has established its presence before IP routing information is manipulated. The message flow in the drawing is as follows:1. The Mobile Terminal activates a PDP Context2. The Mobile Terminal wishes to add a new route and thus, sends a request for modifying the PDP Context with the proposed route.3. The SGSN records the proposed route for itself, and updates the GGSN with the request for modifying the PDP Context with the proposed route.4. The GGSN checks if it is possible to add the proposed route, if it is GGSN updates its routing table, and responds with an updated PDP Context response and the same route. If it is not, either an error message is responded, or an updated proposed route is returned.5. SGSN updates its routing information accordingly.6. The Mobile Terminal checks the response and updates its routing table accordingly

The invention is that the signaling as described above can be used for route addition. The same messages can be used to delete a route as well. However, the main idea is that a new route can be inserted to the Mobile Terminal so that the GGSN and other elements are properly signaled by means of the GTP.

IP-level static route addition in the Mobile Terminal as well as dynamic route addition is enabled by a routing daemon in the Mobile Terminal that results in the presented signaling. Both of these cases converge into kernel forwarding entry injection in the Mobile Terminal, which employs the signaling messages described forFIG. 3.

This implementation contains an API from the IP routing engine of the Mobile Terminal to the GPRS signaling, where the manipulation of kernel routes or alias addresses through the usual IP routing socket API results in the triggering of corresponding PDP context modification signals.

In one embodiment, the invention could be implemented by adding information to an activate PDP Context message [24.008] and adding a GTP extension to GTP [29.060]. This would then allow the insertion and deletion for a route without opening PDP Contexts. Also, the operation of the invention may be detected by a protocol analyzer coupled to a network.