KR20070031464A - System and associated mobile node, foreign agent and method for link-layer assisted mobile IP fast handoff from a fast-access network to a slow-access network - Google Patents

Abstract

The system for handing off a mobile node includes a mobile node and a target agent. The mobile node can communicate with the anchor agent and can also be handed off from the anchor agent. The mobile node may establish a tunnel between the mobile node and the target base station associated with the target agent. The mobile node can then establish a link layer connection between the mobile node and the target agent via the anchor agent and its tunnel. The mobile node then registers with the target agent, causing the mobile node to bind to the target agent so that the data packet (s) pass through the target agent, past the link layer connection and the physical layer connection, independent of the anchor agent and tunnel. To be delivered.

Description

System and associated mobile node, foreign agent and method for link-layer assisted mobile IP fast handoff from fast access network to slow access network from a fast-access network to a slow-access network}

The present invention relates generally to systems and methods for handing off a mobile node from one router to another, and more particularly to link layer-assisted high-speed mobile nodes from one router on a fast access network to another router on a slow access network. A system and method for making handoffs.

Mobile Internet Protocol (IP) allows a mobile terminal to move freely from one connection point to another connection point on various networks visited along its route. In particular, the MIP protocol describes operations that may allow a mobile terminal to maintain a connection during handover from one access router to another. Handover of a typical mobile terminal, however, requires link layer and IP layer signaling. And during this signaling phase, the mobile terminal cannot transmit or receive data packets. This period is called the handoff delay. In many situations, handoff delay may not be allowed to support real time or delay sensitive network traffic. Thus, seamless mobility management techniques may be required for such services. In this regard, seamless mobility management can reduce or prevent service interruptions, packet loss, and handoff delays, thereby improving quality of service (QoS).

As can be seen, seamless handoff can be achieved through fast handoff and context transfer. However, the normal fast handoff mechanism only reduces the IP layer signaling delay and does not pay attention to the link layer delay. In this regard, there is currently no standard technique for reducing handoff delay when a mobile terminal moves from one link layer technology to another. For example, a mobile terminal moving from a WLAN to a CDMA network still experiences latency due to physical layer and link layer signaling during handover from one network to another.

As can also be appreciated, different networks can be classified as fast access networks (eg, WLAN, WiMAX, Bluetooth, etc.) or slow access networks (eg, CDMA, GPRS, 1XEV-DO, etc.). Thus, when a mobile terminal roams from one network to another, there are four possibilities with regard to the access speed of the network: that is, the mobile terminal roams from (1) a fast access network to another fast access network, or ( 2) roam from a slow access network to a fast access network, (3) roam from a fast access network to a slow access network, or (4) roam from a slow access network to another slow access network. When roaming from a slow access network to another slow aggle network, the mobile terminal may more specifically (a) roam from one slow access network to another slow access network of the same type (e.g., handoff between PDSNs of a CDMA network), (b) roam from a slow access network to another slow access network of another type (eg, CDMA to GPRS).

Link layer delay during MIP fast handoff is generally not a problem for mobile terminals roaming from a fast access network to another fast access network or from a slow access network to a fast access network, which is a link layer setup of such handoffs. ) Is typically very fast (eg, hundreds of milliseconds). However, for mobile terminals roaming from a fast access network to a slow access network, or roaming from a slow access network to another slow access network, link layer support can provide the advantage of preventing or at least reducing the delay due to link layer setup. Can be.

In view of the above background, embodiments of the present invention provide an improved system and associated mobile nodes, agents and methods for performing link layer assisted fast handoff from one connection point to another connection point on multiple networks visited along the route. Suggest. Embodiments of the present invention can reduce link layer delay that may be associated with such handoff while handing off a terminal from one connection point to another. More specifically, embodiments of the present invention can reduce link layer delay when a mobile terminal is handed off from a fast access network to a slow access network.

According to one aspect of the present invention, a system for handing off a mobile node is proposed. The system includes a mobile node and a target agent (eg, target home or external agent), and may also include a correspondent node. The mobile node may communicate with an anchor agent (eg, target home or external agent) and may be handed off from the anchor agent. To enforce the handoff, the mobile node may establish a physical layer connection between the mobile node and the target base station associated with the target agent. The target agent may establish a tunnel between the target agent and the anchor agent. The mobile node can then establish a link layer connection between the mobile node and the target agent via the anchor agent and the tunnel between the anchor agent and the target agent. By establishing a tunnel between an anchor agent on the fast access network and a target agent on the slow access network, and by establishing an anchor agent and a link layer connection through the tunnel, the system delays in establishing a link layer connection with the target agent. Can be reduced.

After the link layer connection is established, the mobile node can register with the target agent, so that the mobile node is connected to the target agent so that the data packet (s) sent between the mobile node and the partner node pass through the target agent, and the link Through layer connection and physical layer connection, it is delivered regardless of anchor agent and tunnel. More specifically, after the mobile node registers with the target agent, the target agent can receive data packets from the counterpart node regardless of the anchor agent. The target agent may activate the negotiated link layer context during link layer connection establishment and then forward data packets from the target agent to the mobile node. Similarly, the target agent will be able to receive outgoing data packets from the mobile node. In this case, the target agent may transmit the data packet to the counterpart node according to the link layer context previously negotiated regardless of the anchor agent and the tunnel.

The mobile node may establish a link layer connection before completing the establishment of the physical layer connection. In such a case, the mobile node may make a physical layer connection regardless of the anchor agent and the tunnel. Alternatively, the mobile node may establish a physical layer connection through an anchor agent, a tunnel between the anchor agent and the target agent, and an interface with the target base station. More specifically, in that case the mobile node can receive at least one network parameter of the network containing the target agent (eg, slow access network) and then establish a connection with the anchor agent to communicate with the anchor agent. . The mobile node can then establish a physical layer connection through the previously established interface based on the at least one network parameter.

According to other aspects of the present invention, a mobile node to be handed off, an agent and a method for handing off a mobile node are proposed. Accordingly, embodiments of the present invention propose an improved system, related mobile node, agent and method for handing off a mobile node. As indicated above, and as described below, embodiments of the present invention can reduce link layer delay that may be associated with such handoff while handing off a terminal from one connection point to another. In this regard, by establishing a link layer connection between the mobile node and the target agent through the tunnel between the anchor agent and the anchor agent and the target agent, the link layer delay due to link layer and IP layer signaling is prevented or reduced. The handoff of the node is complete. Then, after the mobile node registers with the target agent, it goes through the target agent, passes through the physical layer connection and link layer connection, and data packets are transmitted between the mobile node and the partner node regardless of the tunnel between the anchor agent and the target agent and the anchor agent. Can come and go As such, the system, mobile node, agent and method according to embodiments of the present invention solve the problems identified by the prior arts and provide additional advantages.

In describing the present invention through general terms, reference will be made to the accompanying drawings, which are not necessarily shown as follows:

1 is a block diagram of one type of mobile node and system that may benefit from embodiments of the present invention;

2 is a schematic block diagram of an entity that may act as a mobile node, home agent, foreign agent and / or counterpart node, in accordance with embodiments of the present invention;

3 is a schematic block diagram of a mobile node according to an embodiment of the present invention;

4 illustrates a multi-layer protocol stack with a seven-layer including OSI model of a node according to one embodiment of the present invention;

5 is a comparison with the OSI function and general OSI model of a node according to an embodiment of the invention;

6 is a control flow diagram illustrating communication between various entities performing a method of handing off a mobile node from a current anchor foreign agent to a new target foreign agent, in accordance with an embodiment of the present invention;

7 is a control flow diagram illustrating communication between various entities performing a method of handing off a mobile node from a current anchor foreign agent to a new target foreign agent, in accordance with another embodiment of the present invention.

The invention will now be described in more detail with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. However, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like reference numerals refer to like elements throughout.

Referring to FIG. 1, a diagram is provided of one type of system that can benefit from the present invention. Systems, methods, and computer program products according to embodiments of the present invention will be described primarily in conjunction with mobile communications applications. However, it should be appreciated that the systems, methods, and computer program products according to embodiments of the present invention may also be utilized in conjunction with a variety of applications, both inside and outside the mobile communications industry. For example, systems, methods, and computer program products according to embodiments of the present invention may be utilized with wired and / or wireless network (eg, Internet) applications.

As shown, the system is shown in FIG. 1 (described below as being shown as including anchor BS 14a supporting high speed network access and target BS 14b supporting low speed network access during handoff). It may include a mobile node (MN) 10 capable of transmitting a signal to and receiving a signal from base sites or base stations (BS) 14. The base station is part of one or more cellular or mobile networks, each containing elements necessary for network operation, such as a mobile switching center (MSC) (not shown). As is well known to those skilled in the art, mobile networks are also referred to as Base station / MSC / Interworking function (BMI). In operation, the MSC may route calls to / from the terminal as the terminal originates and receives calls. The MSC may also support connection to terrestrial relay lines when the terminal is involved in a call. In addition, the MSC may control the delivery of messages to / from the terminal and may also control the delivery of messages to / from the messaging center for the terminal.

The MN 10 may be connected with a data network. For example, BS 14 may be connected to a data network such as a local area network (LAN), metropolitan area network (MAN), and / or wide area network (WAN). In one exemplary embodiment, the BS is connected to a gateway, which is connected to a data network such as an Internet Protocol (IP) network 16. The gateway may include any one of a variety of entities capable of supporting network connectivity between the MN and other nodes directly or indirectly connected to the data network. As can be appreciated, the gateway is a home agent (HA) 18 (hereinafter shown and described as including an anchor FA 20a and a target FA 20b during a fast handoff), a packet data service node (PDSN) , Access router (AR) and so forth. In this regard, as defined in the MIP protocol, the HA has a router in the MN's home network 22. The HA can tunnel data to be transmitted to the MN when the MN is far from home and maintain the current location information of the MN. Meanwhile, the FA has a router in the network 24 visited by the MN. The FA provides routing services to the MN while the MN is registered with the visited network. In operation, the FA detunnels data from the HA and transmits the data to the MN. Then, the FA can function as the default router for the data sent from the MN registered in the visited network.

Other nodes connected to the MN 10 via the IP network 16 may include any of a number of various devices and systems capable of communicating with the MN in accordance with embodiments of the present invention. Other nodes may include, for example, personal computers, server computers, and the like. In addition or alternatively, for example, one or more CNs may include other MNs such as mobile phones, portable digital assistnat (PDA), pagers, laptop computers, and the like. As described herein, a node capable of communicating with the MN via an IP network is called a counterpart node (CN) 26, one of which is shown in FIG.

While not every component of every possible network is shown and described herein, it should be appreciated that the MN 10 may be connected to any one or more of a number of various networks. In this regard, the mobile network (s) may support communication in accordance with any one or more of numerous second generation (2G), 2.5G and / or third generation (3G) mobile communication protocols and the like. Additionally or alternatively, the mobile network (s) may support communication by any of a number of different wireless networking technologies, including WLAN technology such as IEEE 802.11, WiMAX technology such as IEEE 802.16, and the like. Further here, for example, the mobile network (s) may include DVB networks, including Digital Video Broadcasting-Terrestrial (DVB-T) and / or DVB-H (DVB-Handheld), Integrated Services Digital Broadcasting-Terrestrial (ISDB-T). Communication may be supported according to any one or more of a number of various digital broadcast networks, such as ISDB networks, and the like.

More specifically, for example, MN 10 may be connected to one or more networks capable of supporting communication in accordance with 2G communication protocols IS-136 (TDMA), GSM, and IS-95 (CDMA). Also, for example, one or more network (s) may support communication in accordance with 2.5G wireless communication protocols GPRS, Enhanced Data GSM Environment (EDGE), and the like. In addition, one or more network (s) may support communication in accordance with 3G wireless communication protocols such as Universal Mobile Telephone System (UMTS) using Wideband Code Division Multiple Access (WCDMA) radio access technology. In addition, one or more network (s) may support enhanced 3G wireless communication protocols such as 1XEV-DO (TIA / EIA / IS-856) and 1XEV-DV.

Referring now to FIG. 2, shown is a block diagram of an entity capable of operating as an MN 10, HA 18, FA 20 and / or CN 26, in accordance with an embodiment of the present invention. . Although shown as separate entities, in some embodiments, one or more entities may support one or more MN, HA, FA, and / or CN that are logically independent but located together in the entity (s). For example, a single entity can support HAs and CNs that are logically independent but co-located. In addition, for example, a single entity may logically support independent and co-located FAs and CNs.

As shown, an entity capable of operating as MN 10, HA 18, FA 20 and / or CN 26 may generally include a processor 30 coupled to memory 32. . The processor may also be coupled to at least one interface 34 or other means for transmitting and receiving data, content, and the like. The memory may include volatile and / or nonvolatile memory, and usually stores content data and the like. For example, memory typically stores content transmitted from and / or received by an entity. Also, for example, the memory typically stores software applications, instructions for the processor to perform the steps associated with the operation of the entity in accordance with embodiments of the present invention.

Referring now to FIG. 3, here is illustrated one type of MN 10 that may benefit from embodiments of the present invention. However, the MN to be illustrated hereinafter and described hereinafter is only intended to exemplify one type of MN which can benefit from the present invention, and therefore should not be used to limit the scope of the present invention. While several embodiments of an MN are shown and will now be described by way of example, other types of MNs, such as PDAs, pagers, laptop computers, and other types of electronic systems, may naturally be utilized in the present invention.

As shown, the MN 10 may include, in addition to the antenna 36, a transmitter 38, a receiver 40, and a controller 42 or other processor that provides and receives signals to the transmitter and the receiver, respectively. These signals include signaling information in accordance with the propagation space interface specification of the applicable cellular system, and user speech and / or user generated data. In this regard, the MN may operate as one or more airspace interface specifications, communication protocols, modularity types, and access types. More specifically, the MN may operate in accordance with any of a number of second generation (2G), 2.5G and / or third generation (3G) communication protocols, and the like. For example, MN is a 2G wireless communication protocols such as IS-136 (TDMA), GSM and IS-95 (CDMA), 2.5G wireless communication protocols such as GPRS and / or EDGE, and / or UMTS utilizing WCDMA radio access technology. Can operate according to 3G wireless communication protocols. Also, for example, the MN may operate in accordance with enhanced 3G wireless communication protocols such as 1XEV-DO (TIA / EIA / IS-856) and IXEV-DV. Further, for example, the MN may operate in accordance with any one of a variety of different wireless networking technologies, including WLAN technology such as IEEE 802.11, WiMAX technology such as IEEE 802.11.

It can be seen that the controller 42 includes the circuitry necessary to build the audio and logic functions of the MN 10. For example, the controller may be comprised of a digital signal processor device, a microprocessor device, and various analog-to-digital converters, digital-to-analog converters, and other supporting circuits. The MN's control and signal processing functions are assigned among these devices according to their respective specifications. The controller may additionally include an internal voice coder (VC) 42a and may include an internal data modem (DM) 42b. The controller may also include the function of operating one or more software programs to be stored in the memory (described below). For example, the controller can run a connection program, such as a conventional web browser. The connection program can then cause the MN to send and receive web content, such as in accordance with HTTP and / or Wireless Application Protocol (WAP).

The MN 10 may also include a user interface including conventional earphones or speakers 44, a ringer 46, a microphone 48, a display 50, and a user input interface. All are connected to the controller 42. The user input interface that allows the MN to receive data may include any of a number of devices that allow the MN to receive data, such as a keypad 52, touch display (not shown) or other input device. In embodiments that include a keypad, the keypad includes the usual number (0-9) and associated keys (#, *), and other keys used for MN operation. Although not shown, the MN may include a battery, such as a vibrating battery pack, that not only powers the various circuits needed to operate the MN, but also optionally provides mechanical vibration as a perceivable output.

The MN 10 may also include one or more means for sharing and / or acquiring data. For example, the MN may include short range radio frequency (RF) transceivers or interrogators 54 to enable sharing and / or obtaining data with and from electronic devices in accordance with RF technology. The MN may additionally or alternatively include other short range transceivers such as, for example, infrared (IR) transceivers 56, and / or Bluetooth (BT) transceivers 58 that operate using Bluetooth brand wireless technology developed by the Bluetooth Specialty Group. Can include them. As such, the MN may additionally or alternatively be able to transmit / receive data to / from electronic devices in accordance with such technology.

The MN 10 may also include a memory, such as a subscriber identity module (SIM) 60, a removable user identity module (R-UIM), and the like, which generally stores information elements associated with a mobile subscriber. In addition to the SIM, the MN may include other removable and / or fixed memories. In this regard, the MN may include volatile memory 62, such as volatile RAM (RAM), including a cache area for temporary storage of data. The MN may also include other non-volatile memory 64 that is embedded and / or removable. Non-volatile memory may additionally or alternatively include EEPROM, flash memory, and the like. These memories can be used by the MN to store any of a number of software applications, instructions, information, and data that enable the MN to implement its functionality. For example, these memories may include international mobile equipment identification (IMEI) codes, international mobile subscriber identification (IMSI) codes, mobile station integrated services digital network (MSSIS) codes (mobile phone numbers), and IP addresses that uniquely identify the MN. And identifiers such as SIP (Session Initiation Protocol) addresses.

As described in the background description, MIP allows the MN 10 to move freely from one connection point to another connection point of the various networks it has visited. In particular, the MIP protocol describes operations that allow the MN to maintain a connection during handover from one access router to another. Briefly, MIP allows a mobile node to be identified as its home address, regardless of the current connection point to IP network 16. When the MN is on the visited network 24 away from the home network 22, it is also associated with a care-of-address that provides information about the current location of the MN. In general, during the handoff between FAs 20, the care of address changes but the home address remains the same.

As also discussed in the background description, a typical MN 10 handover requires link layer and IP layer signaling, during which the MN will not be able to transmit or receive data packets. Under various circumstances, such handoff delays may not be tolerated in providing real time or delay sensitive network traffic. As an EK, seamless mobility management techniques may be needed for such services. In this regard, seamless mobility management can improve quality of service (QoS) by reducing or preventing service interruptions, packet loss, and handoff delays. And while seamless handoff can be achieved through fast handoff and context transfer, the general fast handoff mechanism only reduces the IP layer signaling delay, but not the link layer delay.

Accordingly, as will be described in greater detail below, embodiments of the present invention will enable link layer assisted fast handoff from one connection point to another connection point on other networks visited by the MN 10 along the route. Can be. Embodiments of the present invention can reduce the link layer delay that may be associated with such handoff while handing off the MN from one connection point to another. More specifically, embodiments of the present invention can reduce link layer delay when an MN is handed off from a fast access network to a slow access network. For information on techniques to reduce link layer delay when an MN is handed off from a slow access network to another slow access network of the same or different type, see System and Associated Mobile Node, Foreign Agent and Method for Link, June 29, 2004. US Patent Application No. 10 / 880,385, filed as Layer assisted Mobile IP Fast Handoff, the contents of which are hereby incorporated by reference in their entirety.

Before describing a link layer fast handoff method according to various embodiments of the present invention, a protocol stack of one node (e.g., MN 10, CN 26, etc.), and a node according to embodiments of the present invention. Reference is made to FIG. 4, which illustrates a comparison of a protocol stack with a general Open Systems Interconnection (OSI) model. More specifically, FIG. 4 shows an application layer 68, a presentation layer 70, a session layer 72, a transport layer 74, a network layer 76, a data link layer 78, and a physical layer 80. Illustrates an OSI model 66 with seven layers including a. This OSI model was developed by the International Organization for Standardization (ISO) and is described in ISO 7498 under the name The OSI Reference Model, the contents of which are incorporated herein by reference in their entirety.

Each layer of the OSI model 66 performs a specific data communication task, service, for a layer preceding that layer (eg, the network layer 76 provides a service for the transport layer 74). The process can be likened to the process of putting a letter into a series of envelopes before the letter is sent through the postal system. For each subsequent envelope, add another layer with the processing or overhead information needed to handle the task (transaction). All the combined envelopes help ensure that the letter reaches the correct address and that the received message is the same as the message sent. Once the entire package has been received at that destination, the envelopes are opened one by one until the letter itself appears exactly as it was written.

The actual data flow between two nodes (e.g., MN 10 and CN 26) is directed from top (82) to bottom (84) within the source node along the communication line and bottom (84) within the destination node. Head to the top (82). Each time user application data progresses from one layer in the same node down to the next, more processing information is added. When the information is removed and processed by the counterpart's corresponding layer, it causes several tasks (error correction, flow control, etc.) to be performed.

The ISO includes all seven layers that are specifically defined, which are organized below in the order that data actually flows when leaving the source node.

Layer 7, application layer 68, which provides a user application to interface with the OSI application layer. And as indicated above, the OSI application layer may have a corresponding peer layer in another node that communicates with that application layer.

Layer 6, presentation layer 70, which allows user information to be in a format (ie, grammar or sequence of 0s and 1s) that the destination node can understand or interpret.

Layer 5, session layer 72, which supports synchronous control of data between nodes (ie, makes the bit configuration through layer 5 of the source identical to the bit configuration through layer 5 of the destination).

Layer 4, transport layer 74, which ensures that an end-to-end connection has been established between the two nodes and is usually reliable (i.e., layer 4 of the destination justifies the connection request, In other words, it confirms that it has received from layer 4 of the source node).

Layer 3, network layer 76, which supports routing and relaying of data through the network (among other things, the address is written on the envelope at the outgoing side of layer 3, which is at layer 3 of the destination. Will be read).

Layer 2, data link layer 78, which includes data flow control when messages are passed down through this layer in one node and up through the corresponding layer of the partner node.

Layer 1, physical interface layer 80, which includes methods by which the data communication device is mechanically connected, and means by which data is to be moved through this physical connection from layer 1 of the source node to layer 1 of the destination node. .

FIG. 5 illustrates a comparison 86 of OSI functions and generic OSI models of MN 10 and / or CN 26 in accordance with embodiments of the present invention. More specifically, FIG. 5 shows that the Internet Protocol (IP) network layer 94 fits into the OSI seven layer model 88. As shown, the transport layer 90 may include mechanisms to provide data connection services to applications and to ensure that data is delivered without error and sequentially without errors. The transport layer of the TCP / IP model 92 passes the segments to the IP layer and sends them to the IP layer, which routes them to the destination. The transport layer allows incoming segments from the IP layer, determines which application is the recipient, and passes the data to the application in the order in which the data came in.

Thus, IP layer 94 performs network layer 96 functions and routes data between nodes (eg, MN 10 and CN 26). The data can be relayed across one link or along several links in IP network 16. Data is carried in units called datagrams, which include IP headers containing layer 3 (98) addressing information. Routers check the destination address in the IP header to send datagrams to their destinations. The IP layer is called connectionless because every datagram is routed independently and the IP layer does not guarantee stable or sequential transmission of the datagram. The IP layer routes its traffic without minding which application-to-application interaction a particular datagram belongs to.

The Transmission Control Protocol (TCP) layer 90 supports stable data connections between devices using TCP / IP protocols. The TCP layer operates on top of IP layer 94, which is used to pack data into data packets, sometimes referred to as datagrams, and to transmit the datagrams over an underlying network via the data link layer and the physical layer. The data link layer can operate according to any of a variety of different protocols, such as point-to-point protocol (PPP). As can be seen, the IP protocol does not include any flow control or retransmission mechanisms. This is the reason why TCP layer 90 is typically used above IP layer 94. In this regard, TCP protocols support acknowledgment for detecting lost data packets.

Now, for example, during a communication session between MN 10 and CN 26, a control flow diagram of how to handoff MN 10 from current anchor FA 20a to new target FA 20b is shown. See 6. As described herein, the MN is handed off from the anchor FA to the target FA. However, it should be appreciated that the MN can be handed off from anchor HA 18 to target FA, or otherwise anchor FA to target HA, without departing from the spirit and scope herein. In addition, as described below, the method of FIG. 6 may be specifically applied to handoff an MN from a slow access network to a slow access network of the same type. In this regard, the method of FIG. 6 will be described in conjunction with handing off an MN from an anchor PDSN (ie, anchor FA) of a CDMA network to a target PDSN (ie, target FA) in the same or different CDMA network. However, it should be appreciated that the method of FIG. 6 can be applied to handoff from any of several different slow access networks to the same type of slow access networks without departing from the spirit and scope of the present invention.

As shown in FIG. 6, the method of handing off the MN 10 from the anchor FA 20a to the target FA 20b in accordance with an embodiment of the present invention provides that the MN receives the IP d address of the target FA from the anchor FA. Requesting. More specifically, the MN may monitor the signal strength of both the fast access network and the slow access network. In this regard, the link layer (ie, layer 2) termination point for the MN and the target FA on the slow Agges network coexist in the same node. Since the MN monitors the signal strengths, when the MN recognizes that the signal strength of the fast access network falls below the threshold signal strength, the MN may request the IP address of the anchor FA.

The MN 10 may request the IP address of the target FA 20b according to any of various methods. For example, the MN is defined in the Internet Engineering Task Force (IETF) RFC document RFC 3220 (January 2002) entitled IP Mobility Support for IPv4, which is incorporated herein by reference in its entirety. The target FA IP address can be requested by sending a proxy router petition, such as a proxy router petition included as a form, to the anchor FA 20a. As can be appreciated, the RFC 3220 proxy router petition technique may require a link layer address, but the MN will not know the IP address of the target FA or the link layer (ie, layer 2) address. However, since fast access networks such as WLANs usually have a geographically fixed coverage, the anchor FA can be preconfigured as the IP address of the target FA to which the MN is to be handed off. In such a case, the anchor FA and the target FA may have a preset security relationship.

Thus, in order for the anchor FA 20a to properly interpret the proxy router petition, the MN 10 may change the proxy router petition by setting a proxy router petition of the "W" bit reserved in other cases. Upon receiving the changed proxy router petition, the anchor FA may send MN information about the target FA 20b so that the MN can then register with the target FA. In one embodiment, for example, the anchor FA is MN, defined in the IETF Internet draft draft-ietf-mobileip-fast-mipv6-08.txt entitled Fast Handovers for MIPv6. Proxy router advertisement messages, which are incorporated by reference in their entirety in this specification, may be transmitted. As defined in the IETF Internet Draft, the Proxy Router Advertisement Message is defined in IETF RFC 3220 (January 2002) under the title IP Mobility Support for IPv4, which is hereby incorporated by reference in its entirety. Based on. In this regard, the proxy router advertisement message may include a mobility agent advertisement extension with the referral address (ie, IP address) of the target FA.

After sending the modified proxy router petition, the MN 10 may initiate a physical layer (i.e. layer 1) connection with the slow access network and, more specifically, the target BS 14b of the slow access network, and the target BS Can then serve the MN. As the physical layer connection is initiated, the MN may generate or be assigned a unique connection ID. For example, in the case of a handoff from a WLAN network to a CDMA network, the MN may initiate a new physical layer connection with the target BS in accordance with the CDMA service option (SO) 33. When establishing a new physical layer connection, the MN may utilize a new service criteria identifier (SR_ID) associated with the new physical layer connection. In addition, when establishing a new physical layer connection, the target PCF (which may be integrated in the target BS) may establish an R-P connection with the target PDSN (ie, the target FA 20b) with the new SR_ID. For a more detailed description of SO 33, see Data Service Option Standard for Spread Spectrum Systems-Addendum 3: cdma2000 High Speed Packet Data Device Option 33 in the Telecommunications Industry Association / Electronics Industry Collaboration Specification TIA / EIA / IS-707-A-3. (February 2003).

Further, either when or after the physical layer connection is initiated between the MN 10 and the target BS 14b, the anchor FA 20a and the target FA 20b may establish a tunnel between them. More specifically, during the physical layer connection initiation, a tunnel may be established between the target FA and the anchor FA via signaling between respective BSs and related network components. For example, when handing off from a WLAN network to a CDMA network, a tunnel may be established between the target PDSN (ie, target FA) and the anchor AR (ie, anchor FA).

Then, during the establishment of the physical layer connection initiated between the MN 10 and the target BS 14b, the MN 10 may be configured, for example, after a unique connection ID (e.g., SR_ID) is generated, and then in a slower access network, more specifically, a low speed. A link layer (ie, layer 2) connection can be established with the target FA 20b of the access network. Instead of establishing a link layer connection through the physical layer connection initiated between the MN and the target BS after establishing the physical layer connection, the link layer connection passes through the tunnel between the anchor FA 20a and the anchor FA and the target FA, It may be preferably set with FA. Since the high speed link with the anchor FA has a shorter round trip time (RTT) than the slow access interface, link layer connection establishment may require a shorter period of time than setting up that link layer connection over the previously initiated physical layer connection.

For example, when handed off from a WLAN network to a CDMA network, after the MN 10 sends an outgoing message of the SO 33 to the target BS 14b, the MN sends a WLAN / AR (ie, anchor FA 20a). PPP negotiation with the target PDSN (i.e., the target FA 20a) can be initiated. In this regard, PPP data frames can be sent from the MN to the anchor AR and tunneled to the target PDSN via the anchor AR. (33) Since the configuration takes place over the high speed link while occurring over the low speed link, PPP negotiation with the target PDSN may in many cases be completed prior to setting up the SO 33. Thus, the target PDSN is connected to the underlying physical layer connection. In this case, the PPP negotiation can be performed without setting the extension.In this regard, an extension to the link control protocol (LCP) is added, so that the SR_ID generated during the initiation of the physical layer connection between the MN and the BS (that is, the unique connection) ID) can be informed to the target PDSN. The extension may include any of a number of various information, but in an exemplary embodiment, the mobile ID (MIN) and / or electronic serial number (ESN) of the MN may be included as well as the SR_ID.

After establishing the slow access network and, in more detail, link layer (i.e. layer 2) connection with the target FA 20b, the MN 10 receives information (eg, entrusted) received from the anchor FA 20a via a proxy router advertisement. MFA registration with the target FA). In this regard, the MN may send a MIP registration request to the target FA. However, as can be appreciated, since the link layer connection can be established over the high speed link before the physical layer connection over the low speed link, the MIP registration can take place via the tunnel between the anchor FA and the target FA and the target FA 20b. have. Thus, the anchor FA may first receive the MIP registration request, and then route the MIP registration request to the target FA to cause MN registration with the target FA.

After receiving the MIP registration request, the target FA 20b processes the registration request and relays the request to the HA 18 of the MN 10 to the target FA including the registration request to the HA and the referral address of the target FA. Can inform information about When the various entities operate according to IPv4 (IP version 4), the HA adds the necessary information, including the target FA referral address, to the routing table for the MN, approves the request and passes the registration response back to the MN via the target FA. can send. Conversely, when objects operate according to IPv6 (IP version 6), the HA can send a registration response back to the MN after accepting the request, which then sends a binding update to the HA or CN 26. Can be. The HA can then add the necessary information to the routing table for the MN. See IETF RFC 3220 and the Internet draft draft-ietf-mobileip-fast-mipv6-08.txt for more detailed information on such a MIP registration process.

As can be appreciated, upon registering the MN 10 with the target FA 20, forward packets coming into the MN are routed to the target FA 20b and then to the MN, which then goes to the anchor FA 20a. This is different from routing to the MN. However, before the physical layer (ie, layer 1) connection is completed between the MN and the slow access network, packets entering and exiting the MN will still be routed through the tunnel between the target FA and the target FA and the anchor FA. . Then, when the physical layer (ie, layer 1) connection is completed between the MN and the slow access network, and the incoming data packets from the CN 26 reach the target FA, the target FA negotiates earlier during the establishment of the link layer connection. Enabled link layer (ie layer 2) context information. For example, when handing off from a WLAN network to a CDMA network, context information can be activated by matching the MIN / ESN and SR_ID. At this time, after activating the link layer context information, the target FA may deliver the incoming data packet to the MN (eg, via the R-P interface) according to the link layer context information. Thus, data packets do not need to be transferred from the target FA to the MN via the tunnel between tunnels between the target FA and the anchor FA as before.

Similarly, after a physical layer (eg, layer 1) connection is completed between the MN and the slow access network, data packets leaving the MN 10 are anchored on the fast access network from the target FA 20b on the slow access network to the CN. It may be delivered without tunneling to the FA 20a. In addition, the MN may close the fast link IP session with the anchor FA, since the fast access network is no longer needed to transmit data packets between the MN and CN. Similarly, since the tunnel between the target FA and the anchor FA is no longer needed to transmit data packets between the MN and CN, the target FA and / or anchor FA may tear down or close the tunnel.

 7 shows a control flowchart of another method of handing off an MN from the current anchor FA 20a to the new target FA 20b at the same time as during the communication session between the MN 10 and the CN 26. Will refer. As described below, the method of FIG. 7 can be applied to handing off MNs in particular from a fast access network to a slow access network. In this regard, the method of FIG. 7 will be described in conjunction with handing off an MN from an anchor AR (ie, anchor FA) in a WLAN network to a target PDSN (ie, target FA) in a CDMA network. However, it should be appreciated that the method of FIG. 7 can equally be applied to MN handoff from any of a number of other fast access networks to any of a number of other low speed networks without departing from the spirit and scope of the present invention.

As shown in FIG. 7, the method of handing off the MN 10 from the anchor FA 20a to the target FA 20b according to another embodiment of the present invention may be performed before the MN establishes a connection with the fast access network. Storing the network parameters for the slow access network at the time of setting. For example, when handing off from a WLAN network to a CDMA network, when the MN is powered up or initialized, the MN can connect to the CDMA channel and the WLAN channel through the MN's CDMA radio frequency (RF) driver and the WLNA RF driver. have. In this regard, after connecting to the CDMA channel, the MN may receive various CDMA network parameters from a message of system parameters and extended system parameters on the paging or forward broadcast channel of the CDMA network. For example, the MN may be the access network ID (ANID), pseudo noise (PN) offset, system ID (SID), network ID (NID) and packet zone of the target BS 14b capable of serving the MN on a slow access network. CDMA network parameters such as ID (PZID) may be received (ANID identifies a target PCF that may be integrated with the target BS).

After receiving the slow access network parameters, the MN 10 may store the slow access network parameters in the MN's memory (eg, nonvolatile memory 64) or the like. Also, upon or after receiving the slow access parameters, the MN may determine to establish a connection with the anchor FA 20b on the fast access network. For example, in a handoff situation from a WLAN network to a CDMA network, after the connection to the CDMA channel and the WLAN channel, the MN may determine the connection establishment with the anchor AR (ie, anchor FA) on the WLAN network, and then the connection. Set. In this regard, after being connected to the WLAN channel, the MN may determine which threshold the WLAN signal strength is above, and if above the threshold, establishes a connection with the anchor AR. Otherwise, the MN may establish a connection with the target PDSN (i.e., the target FA 20a).

At some point after establishing a connection with the anchor FA 20a on the fast access network, the MN 10 may request an IP address of the target FA 20b from the anchor FA. More specifically, for example, the MN can monitor the signal strength of both the fast access network and the slow access network. At this time, similar to the above, when the MN recognizes that the signal strength of the fast access network has fallen below a certain threshold signal strength, the MN may request the IP address of the target FA. As before, the MN may request the IP address of the target FA in any of a number of different ways, such as by sending a proxy router petition to the anchor FA 20a. In such a case, too, as before, the anchor FA may be reset to the IP address of the target FA to which the MN is to be handed off, and the MN 10 sets the proxy router petition, such as by setting the "W" bit of the proxy router petition. You can change it.

Upon receiving the modified proxy router petition, the anchor FA 20a sends information about the target FA 20a to the MN 10 so that the MN can subsequently register as the target FA. In a similar manner as above, for example, the anchor FA may send a proxy router advertisement message to the MN that may include a mobility agent advertisement extension with the referral address of the target FA.

After receiving the information about the target FA 20b, the MN 10 may postpone registering with the target FA and instead instruct the anchor FA 20a to establish a tunnel between the anchor FA and the target FA, Here, the anchor FA and the target FA usually have a preset security relationship. When instructing the anchor FA to establish a tunnel between the anchor FA and the target FA, the MN may transmit slow access network parameters previously received at the anchor FA and stored in the MN. More specifically regarding handoff from WLAN network to CDMA network, for example, the MN sends a setup_CDMA_L1_req message to the anchor AR (ie, anchor FA), where the setup_CDMA_L1_req message is the ANID, PN offset, SID, NID and / or PZID.

In response to receiving the command from the MN 10, the anchor FA 20a may establish a tunnel with the target FA 20b. Also, with the slow access network parameters received from the MN, the anchor FA can interface with the target BS 14b. For example, when handing off from a WLAN network to a CDMA network, a tunnel is established that will create a Generic Routing Encapsulation (GRE) tunnel between the anchor AR (ie, anchor FA), anchor AR, and target PDSN (ie, target FA). The anchor AR may then send the tunnel registration request to the target PDSN, and the message includes the PN offset, SID, NID and PZID of the CDMA BS (ie, target BS).

In response to receiving the tunnel registration request, the target PDSN (ie, target FA 20b) initiates the tunnel establishment process and based on one or more slow access network parameters (eg, ANID, PN offset, SID, etc.). You can configure the target PCF (associated or integrated with the target BS 14b) and the new A10 / A11 interface. In addition, the target PCF can establish a new A8 / A9 interface based on one or more slow access network parameters. As will be appreciated by those skilled in the art, the A9 interface may provide signaling for initiating establishment and teardown of the A8 connection for packet data services. Like the A9 interface, the A11 interface can provide signaling to request establishment, refresh, update and release of the A10 connection for packet data services. The A8 interface can provide a user traffic pass between the target BS and the PCF. The A10 interface can provide a user traffic pass between the target PCF and the target PDSN. More detailed information on the process of setting up such a new packet data service instance can be found in the generalized 3GPP2 specification 3GPP2 A.S0013-A v2.0.1, in particular section 3.17.4.1.

After the tunnel is established between the anchor FA 20a and the target FA 20b and the interface is established between the anchor FA and the target BS 14b, the MN 10 connects to the target BS and the physical layer (ie, layer 1). Can be set. Instead of establishing a physical layer connection directly with the target BS, the MN may establish a physical layer connection with the target BS via a high speed link with the anchor FA, a tunnel between the anchor FA and the target FA, and an interface with the target BS. For example, when handing off an MN from a WLAN network to a CDMA network, the MN may comply with the CDMA SO 33 and initiate a new physical layer connection with the target BS via the WLAN link. In this regard, the MN may send a proxy outgoing message to the WLAN AR (ie, anchor FA), which may include several identical elements, such as a CDMA layer 3 (ie, network layer) outgoing message.

When receiving a proxy outgoing message at anchor AR (i.e. anchor FA 20a), the anchor AR may forward the message through the tunnel to the target PDSN (i.e., target FA 20b), and the target PDSN sends the message. Is transmitted to the target BS 14b. In this regard, the target PDSN may deliver the message to the target PCF via the previously established A8 / A9 interface and from the target PCF to the target BS via the A10 / A11 interface. The target BS may now respond to the proxy origination message as a channel assignment message, which may include several of the same elements included in the CDMA channel assignment message. The target BS may forward the channel assignment message back to the target PCF and from the target PCF to the target PDSN. The target PDSN can now forward the channel assignment message back to the anchor AR via the tunnel, which then forwards the channel assignment message back to the MN 10 over the high speed link between the MN and the anchor AR.

After establishing a physical layer (ie, layer 1) connection with the target BS 14b, the MN 10 may establish a link layer (ie, layer 2) connection with the target FA 20b. Similarly, instead of establishing a link layer connection directly with the target FA, the MN is a high-speed link that establishes a link layer connection with the target FA through a fast link with the anchor FA 20a and a tunnel between the anchor FA and the target FA. In connection with being handed off from the WLAN network to the CDMA network, after receiving the channel assignment message, the MN may initiate a PPP negotiation with the target PDSN (ie, target FA) via the anchor AR (ie, anchor FA). In this regard, the MN may send a setup_CDMA_L2_req message to the anchor AR, and the setup_CDMA_L2_req message includes several PPP parameters.

In response to receiving the setup_CDMA_L2_req message, the anchor AR (ie, anchor FA 20a) sends a message containing the PPP parameters to the target PDSN (ie, target FA 20b) via the tunnel between the anchor AR and the target PDSN. Can be delivered to. The tunnel through which setup_CDMA_L2_req passes may be the same channel previously set, but in a more general embodiment, the anchor AR establishes another tunnel with the target PDSN and forwards its setup_CDMA_L2_req message through the new tunnel, which is indicated by the setup_CDMA_L2_req message. This is because it is related to a different task than the previous one, which includes the message passed through the tunnel. Regardless of whether the anchor AR establishes another tunnel, however, in response to the setup_CDMA_L2_req message including the PPP parameters, the target PDSN may initiate a PPP connection.

Now, after establishing a slow access network and, more specifically, a link layer (i.e. layer 2) connection with the target FA 20b, the MN 10 uses a proxy router advertisement, such as in the manner described above. MIP registration with the target FA may be performed based on the information (eg, a consignment address) received from the anchor FA 20a. More specifically, the MN may transmit a MIP registration request to the target FA via the tunnel between the anchor FA 20a and the anchor FA and the target FA. Thus, the anchor FA may first receive a MIP registration request, and then route the MIP registration request to the target FA to cause MN registration with the target FA. Similar to before, the tunnel that passes when the MIP registration request is forwarded can be any of the previously established tunnels. In a more general embodiment, however, the anchor FA establishes an additional tunnel with the target FA and forwards the MIP registration request over that new tunnel because the MIP registration request is related to another different task.

Again, by registering the MN 10 with the target FA 20, packets subsequently arriving at the MN can be routed to the target FA 20b and then to the MN, which is routed to the MN after the anchor FA 20a. It is different from being. In this regard, when data packets coming from CN 26 reach the target FA, the target FA may activate the previously negotiated link layer (ie, layer 2) context information during link layer connection establishment. Then, after activating the link layer context information, the target FA may forward the incoming data packet to the MN according to the link layer context information. Therefore, data packets need not be forwarded from the target FA to the MN through the tunnel between the target FA and the anchor FA, as before.

Similarly, outgoing data packets from MN 10 may be forwarded from target FA 20b on slow access network to CN 26 without tunneling to anchor FA 20a on fast access network. And, since the fast access network is no longer needed to transmit data packets between the MN and CN, the MN may close the fast FA with the anchor FA. Similarly, since the tunnels between the target FA and the anchor FA are no longer needed to transmit data packets between the MN and CN, the target FA and / or anchor FA may tear down or close the tunnels.

According to one aspect of the present invention, all or some of the systems of the present invention, such as all or some of the MN 10, anchor FA 20a and target FA 20b, generally operate under the control of a computer program product. A computer program product for performing a method in accordance with embodiments of the present invention comprises a computer readable storage medium, such as a nonvolatile storage medium, and computer readable program code portions, such as a series of computer instructions implemented within the computer readable storage medium. Include.

In this regard, FIGS. 6 and 7 are control flow diagrams of a method, system and program product according to the present invention. Each block or step of these control flow diagrams and combinations of blocks in the control flow diagrams may be implemented by computer program instructions. These computer program instructions are loaded into a computer or other programmable device to generate machine language such that the instructions executed on the computer or programmable device create a means for implementing the functions specified in the control flowchart block (s) or step (s). do. These computer program instructions may also be stored in computer readable memory, the memory comprising instructions means for instructions stored in the computer readable memory to implement a function specified in a control flow block (s) or step (s). A computer or other programmable device can be instructed to operate in a particular manner to produce an article of manufacture. Computer program instructions may also be loaded onto a computer or other programmable device such that a series of operating steps are performed on the computer or other programmable device such that the instructions executed on the computer or other programmable device include control flow block (s). Or computer-implemented process to provide steps for implementing the functions specified in step (s).

Thus, the blocks or steps of the control flow diagrams support a combination of means for performing certain functions, a combination of steps for performing certain functions and a program instruction means for performing certain functions. Each block or step of the control flow diagrams and combinations of blocks or steps of the control flow diagrams may be implemented by special purpose hardware-based computer systems that implement particular functions or steps, or by combining special purpose hardware and computer instructions. You can also see.

Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the concepts presented in the foregoing description and the associated drawings. Accordingly, it is to be understood that the invention is not limited to the specific embodiments disclosed, but that such modifications and other embodiments may be included within the scope of the appended claims. Although specific terms have been used in this specification, they are used in a general and descriptive context and are not intended to be limiting.

Claims (27)

In a system for handing off a mobile node, A mobile node capable of communicating with the anchor agent and capable of being handed off from the anchor agent, A target agent capable of establishing a tunnel with the anchor agent, The mobile node may establish a physical layer connection between a mobile node and a target base station associated with the target agent, The mobile node may establish a link layer connection between the mobile node and the target agent through a tunnel between the anchor agent and the anchor agent and the target agent, The mobile node registers with the target agent and associates the mobile node with the target agent, so that at least one data packet sent between the mobile node and the counterpart node passes through the target agent, through the link layer connection and the physical layer connection. And the anchor agent is delivered independent of the tunnel. 2. The system of claim 1, wherein the mobile node may establish a link layer connection before completing the physical layer connection establishment. 3. The system of claim 2, wherein the mobile node is capable of physical layer connection independent of the anchor agent and the tunnel. 2. The system of claim 1, wherein the mobile node can establish a physical layer connection via the anchor agent, a tunnel between the anchor agent and the target agent, and an interface with the target base station. The mobile node of claim 4, wherein the mobile node may receive at least one network parameter for a network comprising a target agent, and then establish a connection with the anchor agent to communicate with the anchor agent, And the mobile node can establish a physical layer connection via a previously set interface based on the at least one network parameter. The method of claim 1, Further comprising a counterpart node capable of communicating with the mobile node, The target agent may receive an incoming data packet from a counterpart node irrespective of the anchor agent, the incoming data packet is received after the mobile node registers with the target agent, The target agent may activate the negotiated link layer context during link layer connection establishment and then forward the data packet from the target agent to the mobile node. The method of claim 1, Further comprising a counterpart node capable of communicating with the mobile node, The target agent may receive an outgoing data packet from the mobile node, the outgoing data packet is received after the mobile node registers with the target agent, The target agent is independent of the anchor agent and the tunnel, but may forward the data packet to a counterpart node according to a link layer context, wherein the link layer context is negotiated during link layer connection establishment and activated by a target agent. System. For mobile nodes, A processor capable of communicating with the anchor agent and allowing handoff from the anchor agent to the target agent, The processor may establish a physical layer connection between the mobile node and the target base station associated with the target agent, The processor may establish a link layer connection between a mobile node and a target agent through a tunnel previously established between the anchor agent and the anchor agent and the target agent, The processor registers a mobile node with the target agent so that the mobile node is associated with the target agent so that at least one data packet sent between the mobile node and the counterpart node via the target agent establishes a link layer connection and a physical layer connection. While passing, the mobile node characterized in that the delivery is independent of the tunnel and the anchor agent. The mobile node of claim 8, wherein the processor may establish a link layer connection before completing the physical layer connection establishment. 10. The mobile node of claim 9 wherein the processor is capable of physical layer connection independent of the anchor agent and tunnel. The mobile node of claim 8, wherein the processor is capable of establishing a physical layer connection through the anchor agent, a tunnel previously established between the anchor agent and the target agent, and an interface with the target base station. The processor of claim 11, wherein the processor is further configured to receive at least one network parameter for a network comprising a target agent, and then establish a connection with the anchor agent to communicate with the anchor agent, And the processor may establish a physical layer connection through a previously set interface based on the at least one network parameter. 10. The method of claim 8, wherein the processor registers a mobile node such that a target agent receives data packets from a partner node independent of the anchor agent, and activates a link layer context negotiated during link layer connection establishment at the target agent. And then forward the data packet to the mobile node. 10. The system of claim 8, wherein the processor registers a mobile node to enable the target agent to receive outgoing data packets from the mobile node, and then link the data packets independent of the anchor agent and the tunnel. A mobile node, characterized in that it can be delivered to a counterpart node according to a link layer context negotiated during layer connection establishment and activated by a target agent. An agent used to handoff a mobile node from an anchor agent, The mobile node may establish a physical connection between itself and a target base station associated with the agent, and establish a link layer connection between the mobile node and the agent through an anchor agent and a tunnel, between the agent and the anchor agent. Includes a processor capable of establishing a tunnel, The processor binds the mobile node to the agent by registering a mobile node such that at least one data packet sent between the mobile node and the partner node passes through the link layer connection and the physical layer connection through the agent, while the anchor agent and the Agents characterized in that they are delivered regardless of the tunnel. 16. The agent of claim 15, wherein the processor establishes a tunnel between the agent and the anchor agent to enable the mobile node to establish a link layer connection before completing the physical layer connection establishment. 17. The agent of claim 16, wherein the processor establishes a tunnel between the agent and the anchor agent to enable the mobile node to make a physical layer connection independent of the anchor agent and the tunnel. The physical layer of claim 15, wherein the processor establishes a tunnel between the agent and the anchor agent such that the mobile node passes through the tunnel between the anchor agent, the anchor agent and the target agent, and an interface with the target base station. Agents that allow for establishing a connection. 16. The method of claim 15, wherein the processor is capable of receiving data packets received from the counterpart node after registering with the mobile node, regardless of the anchor agent, and activating the link layer context negotiated during link layer connection establishment. Agent, characterized in that the forwarding of the packet to the mobile node. 16. The mobile station of claim 15, wherein the processor may receive an outgoing data packet from a mobile node received after registering the mobile node and is independent of the anchor agent and the tunnel, but negotiated during activation of a link layer connection and activated by the agent. And forward the data packet to the counterpart node according to the established link layer context. A method of handing off a mobile node from an anchor agent in communication with the mobile node to a target agent, the method comprising: Establishing a physical layer connection between the mobile node and the target base station associated with the target agent; Establishing a link layer connection between the mobile node and the target agent through an anchor agent and a previously established tunnel between the anchor agent and the target agent; By registering the mobile node with the target agent and associating the mobile node with the target agent, at least one data packet sent between the mobile node and the partner node passes through the target agent, through the link layer connection and the physical layer connection, Causing the transmission to be independent of the tunnel. 22. The method of claim 21, wherein establishing the link layer connection comprises establishing a link layer connection before completing the physical layer connection establishment. 23. The method of claim 22, wherein establishing the physical layer connection comprises establishing a physical layer connection independent of the anchor agent and the tunnel. 22. The method of claim 21, wherein establishing the physical layer connection comprises establishing a physical layer connection via the anchor agent, a tunnel previously established between the anchor agent and the target agent, and an interface with the target base station. Characterized in that. The method of claim 24, Receiving at least one network parameter for a network comprising a target agent; And then Establishing a connection with the mobile node and the anchor agent to enable the mobile node to communicate with the anchor agent, And establishing a physical layer connection through the interface with the target base station comprises establishing a physical layer connection through a previously set interface based on the at least one network parameter. The method of claim 21, Receiving data packets received and received after registering the mobile node with a target agent, from the counterpart node, regardless of the anchor agent, at the target agent; At the target agent, activating the negotiated link layer context during link layer connection establishment; And And forwarding the data packet from the target agent to the mobile node. The method of claim 21, At the target agent, receiving an outgoing data packet received from the mobile node after registering the mobile node with the target agent; And And forwarding the data packet from a target agent to a counterpart node, independent of the anchor agent and the tunnel, but in accordance with a link layer context negotiated during link layer connection establishment and activated by the target agent. .

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