MXPA06012958A - Performing handover by deferring ip address establishment. - Google Patents

Abstract

In a broadband wireless access system, when handover is performed while receiving data, a method of deferring IP address establishment procedures is provided to allow such data to be delivered between the base stations. When the terminal receiving downlink data moves from a first base station region to a second base station region, the first base station delivers the downlink data to the second base station, and the second base station uses a particular message to inform that there is data to be delivered to the terminal such that the IP address establishment of the terminal is deferred.

Description

PERFORMANCE OF THE TRANSFER PROCESS BY DELAYING THE ESTABLISHMENT OF THE INTERNET PROTOCOL DIRECTION TECHNICAL FIELD The present invention relates to a method for maintaining the continuity of the data service in broadband (broadband) wireless (radio) access systems, in particular to a method for establishing IP addresses of a mobile station to maintain continuity of the data service during the handover or in an idle mode.

BACKGROUND OF THE INVENTION In general, in a wireless broadband (radio) access system, an idle mode is held for a mobile (or fixed) terminal (e.g., mobile station, mobile subscriber station (MSS), user terminal, user (UE), etc.), to minimize energy consumption. In idle mode, a "search zone" is defined as the entire region that is managed by a plurality of base stations called "a search group", and all base stations included within the same search area have the same search cycle value (Paging_Cycle) and search offset value (Paging_Offset). The terminal may request the base station to switch to idle mode and the base station delivers its paging-group ID, and the search and search offset cycle associated with the terminal allow the terminal to change to the unoccupied state. During idle mode, the terminal can determine whether to maintain or terminate its idle mode based on the search that is delivered in wide broadcast format from the base station in each search term. Additionally, when there is traffic (for example, data, packets, etc.) that needs to be delivered by the terminal in idle mode, the terminal can end its idle mode at any time. Also, when a terminal in idle mode does not receive a search within a set period, due to reasons such as movement to another search area, loss of synchronization, etc., then the terminal terminates its idle mode. Hereinafter, the procedures of a terminal switching to idle mode and a method of the related technique of setting an IP address when downlink data exist are explained. However, in Figure 1, a method of delivering downlink traffic (data) received by the terminal to a registered base station (BS), particularly from a previous base station (BS), is not defined in the related art. in service) to a new base station (target BS). Also, even if a method of data delivery between the base stations is defined, when the terminal resets an IP address, the data delivered would be useless from the point of view of an application program in the terminal. For example, in Figure 1, if a terminal in idle mode is moved to a search area and is within a zone of another base station BS # 3, when the downlink data arrives at the base station BS # 1 that made the registration release to initially change to idle mode, the base base station BS # 3 informs the terminal to enter the network through a search message. Then the data needs to be delivered from the base station BS # 1 from which the terminal initially switched to idle mode, to the base station BS # 3 currently receiving the search, but the related technique does not define a method of said delivery . Also, even if the above-mentioned problem in the related art is solved, as shown in Figure 2, as the terminal establishes (or resets) the IP address upon receiving the search when there is downlink (data) traffic, the received data are useless from the point of view of the terminal. Accordingly, among the operations described above in the related art, when there is traffic (data) that needs to be delivered to the terminal in the idle mode, a method for receiving the data without the terminal performing the procedures for establishing the data is not defined. IP.

At the same time, when a handover is made in a broadband wireless access system, the terminal releases the connection to the base station that is in service (BS in service), and performs the handover to the target base station ( Target BS) to which the transfer is made. When the terminal performs the handover, a mobile terminal handover indicator (MOB_HO_IND) is delivered to the service BS, and if the value of the handover indicator type (HO_IND__type) is "00", this means that the BS in service is released (release of the BS in service). In the related art, if the value of the type of handover indicator (HO_IND_type) is "00", the BS in service releases all connections and the state machine of the medium control layer (MAC) related to the terminal and the PDUs (Protocol Data Units) of the MAC can be ignored. Also, it is defined that the BS in service can deliver the MAC state machine and the MAC PDUs to the target base station (target BS) to give continuity to the service, or it can be ignored by a request through a message of the trunk axis of the target base station. However, the particular operations that are required to be performed for the terminal to receive have not yet been specified. Accordingly, the present invention defines the operations for receiving the data delivered by the base station prior to the target base station, after the terminal has been moved. Figures 3 and 4 represent two embodiments of handover by means of a mobile terminal. As shown in Figures 3 and 4, in the handover procedures according to a terminal request or a base station request, after the terminal performs initialization procedures for a handover, an indicator of the handover is transmitted. transfer (for example, a MOBJHOJndication) to the base station (BS in service) that is currently receiving the service, and the relation (connection) is released to the base station BS # 1 that receives the service. Then, the terminal performs the remaining procedures to access the target base station BS # 3, particularly the telemetry and initial entry to the network procedures. Figure 5 represents a format of a transfer indicator (MOBJHOJndication). When the relation (connection) is released with the base station BS # 1 that receives the service, the HO-IND-type is set to "00".

BRIEF DESCRIPTION OF THE INVENTION Technical Problem However, regarding the idle mode of the prior art, if the base station in service delivers data to the target base station when the terminal performs a handover, if the terminal that was moved resets the IP address during the reception of the data, the received data become useless. Particularly, as shown in figure 2, without considering whether there is data that is delivered after the handover, the terminal immediately performs the establishment of the IP address, and even if the delivered data is sent to the terminal, said data is useless from the point of view of the application program in the terminal. In this way, in this case, it is necessary to clearly define the time in which the establishment of the IP address must be performed, but the related technique has not done so.

Technical Solution To handle the problems of the related technique, the continuity of the data must be maintained when a transfer is made to a mobile terminal (or when the terminal changes its mode of operation), while the establishment of the IP address also it needs to be done properly to ensure proper communication between the terminal and the network for a broadband (broadband) wireless (radio) access system. In a broadband (broadband) wireless (radio) access system, when a mobile or fixed terminal in an idle mode has downlink data to be received, or when a handover is performed while receiving said data, the IP address set-ups are delayed (delayed) to allow such data to be delivered appropriately between the base stations.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 represents an operation of resetting the IP address when a mobile station switches to idle mode according to the related technique. Figure 2 represents the restoration of the IP address when a mobile station in idle mode changes to receive mode, or when a handover occurs, according to the related technique. Figure 3 represents an example of realization of a transfer on request of a mobile station. Figure 4 represents an example of realization of a transfer by request of a base station. Figure 5 represents a format of a handover indicator according to the related art. Figure 6 represents a format of a data delivery message used in the present invention. Figure 7 depicts a data transmission stop message format used in the present invention. Figure 8 represents an example of a registration response message used in the present invention. Figure 9 represents an example of a telemetry response message according to the present invention.

Figure 10 represents a method of data delivery between base stations, and delay of IP address assignment of a mobile station according to a first embodiment of the present invention. Figure 11 represents a format of a data delivery indicator used in the present invention. Figure 12 depicts an example of registration response message encodings (RNG_RSP) according to the present invention. Figure 13 depicts a method of data delivery between base stations, and of IP address assignment delay of a mobile station according to a first embodiment of the present invention, showing the establishment of the IP address when the base station can not explicitly inform the mobile station about whether data delivery is possible or not. Figure 14 represents a method of the second embodiment of the present invention, wherein the establishment of the IP address is performed when there is no data delivery message other than the base station for a certain amount of time. Figure 15 represents a method of the second embodiment of the present invention, wherein the establishment of the IP address is performed when the base station can explicitly inform the mobile station whether data delivery is possible or not. Figure 16 depicts a method of the second embodiment of the present invention, wherein an example of the procedures for data delivery is given after the base station in service transmits an indicator per request from the mobile station.

DETAILED DESCRIPTION OF THE INVENTION Next, preferred exemplary embodiments of the present invention will be explained. However, those skilled in the art will understand that the features of the present invention should not be limited only to the embodiments described herein. The present invention relates to research and development carried out by various IEEE working groups, such as IEEE 802.16, and therefore the concepts and teachings implied herein are applicable to all features of the present invention. Additionally, as several efforts are made to perform the interdisciplinary work of different types of networks and communication technologies, for example to obtain compatibility between IEEE networks and cellular networks (such as a third generation (3G) network), it is clearly understood that the present invention may also have application to obtain said compatibility. Considering the communication protocols related to the wireless access (radio) systems, at the network layer, to allow the communication of appropriate data packets through the Internet, an Internet Protocol (IP) provides the address establishment information and necessary routing for the packets. Here, each device (for example, user terminal, mobile handset, wireless connectivity device, etc.) connected via the Internet, requires the establishment of a unique IP address for that device to be properly identified and distinguished from others dispositives. The Internet Protocols referred to as IP version 4 (IPv4) and IP version 6 (IPv6) have been developed. Using 32-bit addresses, it has been found that IPv4 has limitations due to the increasing popularity of Internet communications, with which each device connected to the Internet requires its own unique IP address. Therefore, since the availability of 32-bit addresses will soon be exhausted, an improvement was developed, namely, IPv6, which uses 128-bit addresses. However, the fact that a user terminal can have mobility (for example mobile terminals) makes the establishment of IP addresses more difficult. For example, to sustain mobility, a user terminal may experience a handover function, wherein the terminal that is being served by a base station that covers a certain region, moves to a new location and needs to be served by a different base station that covers that new location. In other words, the mobile station that is part of a first subnet (that is, a portion of the network) moves to a second subnet (that is, to another portion of the network). Another example would be when a user terminal changes its operating state from an unoccupied mode to a reception mode, which is an example of an energy-saving mode of operation, which is important because a user terminal having mobility must retain the limited energy of your battery. In such previously described situations of handover or unoccupied mode change, the establishment of the address of! P must be performed at the appropriate time, such that the user terminal can receive the data without interruption. To handle the problems of the related art, in a broadband (broadband) wireless access system (radio), wherein a mobile terminal in idle mode is moved to a region of a second base station that is inside a search area of a first base station, a method according to the present invention for establishing the IP address of the mobile terminal, comprises: when downlink data arrives at the first base station, the first base station delivers the downlink data to the second base station through a first message; the second base station informs the mobile terminal through a second message that there is data to be delivered; and delays the establishment of the IP address to allow the reception of data in the mobile terminal according to the second message. Preferably, the first message is a data delivery message. Preferably, the method of establishing the IP address of the terminal also comprises the step of transmitting a stop message of the data transmission by the first base station to the second base station, after the establishment of the address is completed. of IP. Preferably, the second message is a registration response message or a telemetry response message. In this case, the registration response message includes a parameter that delays the establishment of the address of the terminal P, informing that there is data to be delivered. To achieve this end, in a broadband wireless access system wherein a mobile terminal that receives downlink data is moved to a region of a second base station that is within a search area of a first base station , a method according to the present invention for establishing an IP address of the mobile terminal, comprises: asking whether the first base station can deliver downlink data to the second base station, delivering a handoff indicator of the terminal mobile to the first base station; the first base station, by means of a data delivery indicator, informs the mobile terminal if data delivery is possible, and delivers the downlink data to the second base station; and performing IP address reset procedures after receiving the downlink data of the second base station, upon receipt of the data delivery indicator. Preferably, if the first base station can not explicitly report on the data delivery capability, or if the data delivery indicator is not received over a certain amount of time, the mobile terminal makes an initial entry to the network, it waits for a certain amount of time the arrival of downlink data, and then performs the IP address reset procedures. To achieve this end, in a broadband wireless access system wherein a mobile terminal that receives downlink data is moved to a region of a second base station that is within a search area of a first base station , a method according to the present invention for establishing an IP address of the mobile terminal, comprises: delivering via the mobile terminal a delivery indicator to the first base station; delivering the first base station downlink data to the second base station by means of the data delivery indicator; inform through the end! mobile that there is data to be delivered by the second base station to the mobile terminal by means of a first message; and receiving the downlink data of the second base station after delaying the restoration of the IP address for a certain amount of time according to the first message. Preferably, the first message is a registration response message or a telemetry response message. In a broadband (broadband) wireless access system, as a first embodiment, the present invention proposes a method for delivering data between base stations when there is downlink data to be received by a fixed / mobile terminal in the idle mode, and a method of delay (or delay) of the IP address setting procedures when the mobile terminal switches to receive mode to receive data. Particularly, the present invention defines the procedures for delivering data to a current base station after the data arrives at the base station performing the initial transition procedures of the idle mode, when a mobile terminal switches to idle mode and moves from a region of a base station that performed the transition procedures, to a region of another base station. Also, if the IP address changes when the terminal receives the message delivered by the above procedure, such data would be useless and therefore the present invention defines the procedures in such a way that the IP address setting is not performed in the situation previous. In another embodiment, the present invention provides a method for delivering data between base stations when a handover function is performed during data reception, and a method for deferring the IP address setting procedure while the data is received after a handover function. that the mobile terminal moves to a new location. Particularly, in a broadband wireless access system, the present invention provides a method in which, during the handover of a mobile terminal, the base station currently in service (BS in service) delivers the data received by the mobile terminal to a target base station (target BS) to which the handover is to be made through a backbone network, to guarantee the continuity of the service after the handover. Also, the present invention provides a method that can delay (defer or postpone) the method of establishing the IP address, while the mobile terminal receives data that was delivered to the new base station from a previous base station after perform the transfer. Additionally, the present invention provides a method that allows a mobile terminal to perform a handover function knowing explicitly whether the data that is currently being explicitly received can be received after it is moved, and defines the message delivered from the base station in service to a target base station. Also, the present invention, when the mobile terminal completes the handover, defines a message indicating that the data delivery must be stopped because handover has been completed, which the target base station sends to the serving base station. First of all, a method according to the first embodiment of the invention will be explained, in order to deliver data between the base stations and to delay (defer or postpone) the assignment of the IP address of the terminal. When the handover function is performed, the BS in service can discard the SDUs (service data units) of the MAC associated with the MSS, or issue the MAC SDUs for the continuation of the service. However, the MSS must decide if the MAC SDUs will be issued to the target BS depending on the type of traffic. In this way, the present invention proposes a new method for the MSS to request the release of the MS in service with data transmission. To achieve this, the present invention proposes that the format of the message MOB-HO-IND be modified by adding a HOJNDJype so that the MSS decides on the continuation of the service by issuing MAC SDUs associated with the MSS, as shown in Figure 5. In the case of data dispatch, if the MSS restores IP connectivity after handover, the data issued will be rendered useless due to the IP address change. Therefore, the MSS must defer the restoration of the IP if there are data sent from the BS in service. If the BS decides whether or not to issue the data and the MSS does not know of this decision, the MSS requests the release of the BS in service by sending a management message MOB_HOJND MAC with the value of HOJNDJype indicating the release of the BS in service , and the BS decides whether or not to send the data for the MSS to the target BS. Since the MSS does not know whether the BS in service decides to forward the MSS data to the target BS, the MSS expects some data issued for some predefined time after the handover. If new BS data is received within the predefined time, and the destination is an old IP address, the MSS may choose to defer resetting the IP address until the session ends. If the MSS chooses to terminate the session, it establishes 5 IP connectivity to acquire a new IP address. The new BS can send a backbone message Stop_Data_Forwarding to the old BS when the MSS restores IP connectivity. When the BS in service receives the backbone message Stop_Data_Forwarding, the BS can close all connections and discard 0 status machines and MAC SDUs associated with the MSS. < _: If the MSS can request the release of the BS in service by explicitly issuing data, the MSS does not require waiting a predefined time to verify if there is any data issued to be received after the transfer. In this case, the BS indicates to the MSS its capacity of 5 data dispatch. If the MSS receives an indication that the issuance of data is sustainable, the MSS differs the restoration of IP connectivity, and if the MSS receives an indication that the issuance of data is not sustainable, the MSS restores IP connectivity. without waiting for a predefined time after the transfer. 0 The new BS can send a backbone message Stop_Data_Forwarding to the old BS when the MSS restores IP connectivity. When the BS in service receives the Stop_Data_Forwarding message, the BS can close all connections and discard the status machines and MAC SDUs associated with the MSS. If the MSS, which can explicitly request the release of data, requests the release of the BS in service by sending a management message MOBJHOJND MAC with the value HOJNDJype indicating the release of the BS in service, the MSS does not consider whether the data is issued or not to the objective BS. This MSS initiates the restoration of the IP as soon as the handover ends and registers the new BS. After the establishment of the transfer request / response call has been completed, the MSS can start the actual transfer (HO). At some stage during the HO process, the MSS terminates the service with the BS in service, with or without the option of issuing data. This is done by sending a management message MOBJHOJND MAC with the value HOJNDJype indicating the release of the BS in service without forwarding data, or with the value HOJNDJype indicating the release of the BS in service with forwarding of data to send data to the BS objective. If the HOJNDJype field specifies the release of the BS in service, the BS can close all connections and discard the MAC status machines and the MAC PDUs associated with the MSS, and if the HOJNDJype field specifies the release of the BS in dispatch service can retain the connections, the MAC status machine and the MAC PDUs associated with the MSS by being issued to the target BS to continue the service, until the target BS requests that the BS in service stop the dispatch on a Trunk network. The target BS can compensate the data issued and deliver to the MSS when the handover of the MSS terminates successfully, and at that time, sends the trunk message to advise the serving BS to stop the shipment. The MSS can request the issuance of the data currently received by sending a management message MOBJHOJND MAC with the value HOJNDJype indicating the release of the BS in service with data transmission. This request is made if the MSS wishes to receive the data currently received through the BS in service to continue the service, and the IP reset is deferred until after the handover until the processing of the currently received data ends. Upon receipt of the BS release HOJNDJype in service with data dispatch, the serving BS will send MOB_FWDJND to the MSS over the basic CID, indicating whether or not the BS can issue the data. If the action code in MOB_FWDJND indicates 'unsupported data forwarding', the MSS resets the IP address as soon as the handover is completed, and if the action code indicates 'sustainable data forwarding', then the MSS differs the reset of the IP and receive the data issued. When MSS restores IP connectivity during receipt of data issued, the BS can send a backbone message to request that the old BS stop sending the data. In the first embodiment of the present invention, the following messages are defined: * Data delivery message: A message used by the base station in service when the received data is delivered when the mobile terminal does not move to a base station objective. * Data delivery stop message: A message sent by the target base station to the previous base station to request the stop of data transmission by the mobile terminal. * Registration response message: A message that additionally includes a parameter to defer (delay or postpone) the establishment of the IP address, informing that there is a message (data) to be delivered to the mobile terminal, when the mobile terminal performs procedures register. * Telemetry response message: A message that additionally includes a parameter for deferring the establishment of the IP address, informing that there is a message to be delivered to the mobile terminal, when the mobile terminal performs telemetry procedures. Figures 6 to 9 represent respectively examples of the four types of messages described above, and the parameters used for each message are only examples; therefore they can be changed in the proper way. Here, the data delivery message shown in Figure 6 can also be referred to as an 'MSS data forwarding message', which is a message sent from the BS in service to the target BS for issuing the MAC SDUs of the MMS during the HO. Normally this message is used when the MSS requests the BS in service to release the ZBS in service with data dispatch. Preferably, the transmission of this message will be stopped upon receipt of a data delivery stop message which is explained below. The data delivery stop message shown in Figure 7 may also be referred to as a 'data release stop message', which is a message sent from the target BS to the BS in service to render the BS in service stop the issuance of the MSS SDUs of the MSS. Hereinafter, referring to Figure 10, a method for delivering data between base stations and for delaying (deferring or postponing) the allocation (establishment) of the IP address of the terminal, according to the first mode, will be explained.

Procedures for delivering data between the base stations If the mobile terminal switches to idle mode and the mobile terminal moves from a region of a base station in which the mobile terminal performs the transition to idle mode, to a region of different base station, when data arrives at the base station (BS in service: BS # 1) that performed the initial transition procedures to idle mode, this base station (BS # 1) informs the other base stations ( BS # 2 and BS # 3) that downlink data denied the mobile terminal (MSS) having a particular MAC address (access control to the medium).

Then, all base stations (BS # 2 and BS # 3) within the same search area establish an action code to enter a network using a MAC address to search for mobile terminals. The mobile terminals (MSS) that receive the search perform entry procedures to the network, and the base station (BS objective: BS # 3) with which this procedure is performed to enter the network, informs that there is a search for mobile terminal for its search area to the base station (BD in service), which receives the above data. Accordingly, the base station (BS # 1) delivers the data to the base station (BS # 3) that had an entry to the network that the mobile terminal performs. Here, the data is delivered by including it in a data delivery message, which is a trunk axis message.

Delay of the establishment of the IP address when input to the network is made When the mobile terminal makes entry to the network because it had data to be received, the mobile terminal must defer (delay or postpone) the establishment of the IP address by the two following situations. First, when entering the network according to a search operation code (for example entering the network), after being in idle mode, the setting of the IP address is deferred (delayed or postponed). Second, when the base station explicitly performs registration procedures or telemetry procedures, the fact that there is data to be delivered is reported to the mobile terminal through a registration response message or a telemetry response message, and the mobile terminal differs (delays or postpones) the establishment of the IP address. Also, the mobile terminal can establish the IP address during data reception, and when the IP address is set, the base station receiving the data transmits a transmission stop message, which is a trunk axis message. , to the base station that is delivering the data. Next, a method for delivering data between base stations and for deferring (delaying or postponing) the allocation (establishment) of the IP addresses of the mobile terminal, according to the second embodiment of the present invention, will be explained. The following messages are defined by the first embodiment of the present invention. * Transfer indicator: This indicator requests explicit information on whether it is possible or not to deliver the data that is currently being received. * Data delivery indicator: This indicator allows the base station to inform the mobile terminal if the data delivery is possible. * Data delivery message: This message is used when the base station in service delivers to the target base station the data that would have been received by the mobile terminal if it had not been moved. * Data transmission stop message: This message is used when the target base station requests the previous base station to stop the transmission of data from the mobile terminal. * Registration response message: This message also includes a parameter that differs the establishment of the IP address informing the mobile terminal that there is a message to be delivered, when the mobile terminal performs registration procedures. * Telemetry response message: This message also includes a parameter that differs the establishment of the IP address informing the mobile terminal that there is a message to be delivered, when the mobile terminal performs telemetry procedures. The formats of! The transfer indicator and the data delivery indicator are shown in figures 5 and 11 A, respectively. The formats of each of the four types of messages previously identified are represented respectively in figures 6 to 9. Here, the parameters used for each message are only examples and therefore can be changed in due form. In Figure 11, a MOB_FWDJND_Message-Format flag is shown as an example of a data delivery indicator. The BS sends this message to indicate its ability to issue data when an MSS sends a MAC handling message MOBJHOJND, with the value HOJNDJype indicating release of the BS in service with data dispatch. The action code 00 is sent to indicate to the MSS that the BS can send data to the target BS, and 01 is sent when the BS can not sustain the forwarding of data. Figure 12 depicts an example of registration response message encodings (RNG_RSP) according to the present invention. Referring to Figure 12, during handover (HO), the target BS may notify the MSS, via Bit # 7, about an MSS downlink data pending element (DL) of the TLV item of the MSS. optimization of the HO process in the RNG-RSP, of pending DL data of re-entry MSS to HO. After a successful reentry of the MSS in the target BS (which has now become the new BS in service), and after the new BS in service ends the reception of any data retained and issued from MSS DL pending HO, the MSS can restore IP connectivity and the new BS in service can send a trunk message to request the former serving BS or another network entity to stop forwarding any pending MSS DL data prior to the HO . Next, a method for delivering data between base stations, and for deferring (delaying or delaying) the allocation (establishment) of IP address of the mobile terminal according to the second embodiment will be explained, referring to figures 12 to 15 Here, it should be noted that in Figures 12 to 15, the step of releasing the terminal (MSS) is represented before the initial step of issuing MSS data. However, the box showing the 'MSS release' step is represented in broken lines to indicate that the particular location of this step in the general procedures can be changed at will or if necessary. For example, the MSS release step can be performed near the end of the general procedures instead of the initial steps, if doing so would be more advantageous. Also, in Figures 12 to 14 it should be noted that the data forwarding steps can continue to be performed until the BS in service receives a message indicating that the data delivery must be stopped (Stop_Data_Forwarding) of the target BS. Furthermore, since the features of the present invention have been described for delivering (sending) data between base stations, it should be understood that such forwarding (delivery) of data can be performed directly between the base stations, or by means of an element intermediate network, such as an access center. In other words, as shown in Figure 2, a portion of the network (e.g., a trunk axis!) Can include at least two base stations connected directly to each other, or at least two base stations connected to each other. by means of an access center (or other network element). When the base station can not explicitly inform the terminal about the data delivery capacity: Figure 13 represents the establishment of an IP address when the base station can not explicitly inform the mobile terminal whether or not it is possible to data delivery Referring to figure 13, if there is data that is currently being received, the mobile terminal puts the HOJNDJype of the MOBJHOJND in '00' (= release of the BS in service) and transmits, or puts '11 '(= release of BS in service with data transmission) ) and can transmit to the base station (BS # 1). If the HOJNDJype is OO ', the mobile terminal performs the handover without expecting to receive an explicit data delivery indicator from the base station. In this case, the terminal can not know if the previous base station (BS # 1) can deliver data to the new base station (BS # 2). Accordingly, after handover, the mobile terminal resets an IP address after waiting a certain amount of time to see if there is any data to be delivered from the previous base station (BS # 1). If there is data delivered during said amount of time, the mobile terminal may remove (delay, defer or postpone) the establishment of the IP address while receiving said data, may stop the reception of data at any time, decide whether to receive data through of a path snows, and when the IP reset occurs, the new base station (BS # 2) detects this and delivers a data transmission stop message to the previous base station (BS # 1). Upon receiving the data transmission stop message identified above, the above base station stops the message that is being transmitted, frees (cancels) the MAC state machine with respect to the mobile terminal that was moved and then ignores the SDUs of MAC delivered from a top layer. Figure 14 represents the establishment of an IP address when a base station does not provide an explicit data delivery message. Referring to figure 14, if the mobile terminal transmits the HOJNDJype as '11 ', this means that the mobile terminal expects the base station to explicitly report whether data delivery should be done or not, and if an indicator is received. data delivery of the base station, then the mobile station operates in the same way as when the base station can explicitly inform whether data delivery is possible or not, as shown in Figure 15. However, if the base station does not hold the data delivery indicator, the mobile station waits a certain amount of time, and if the data delivery indicator is not received from the base station, the subsequent operations are performed in the same way as when the HOJNDJype is '00'. When the base station can explicitly inform the terminal about the data delivery capacity: Figure 15 represents the establishment of an IP address when the base station can explicitly inform the mobile terminal about whether delivery is possible or not of data. As shown in Figure 15, when the mobile terminal has data that is currently being received, the HOJNDJype of the MOB-HO-IND can be transmitted after being set to '11' (= release of BS in service with data transmission). ), to receive from the base station an explicit indicator that indicates whether data delivery is possible or not. If the base station (BS # 1) holds the HOJNDJype of! transfer indicator (MOB-HO-IND), then the base station (BS # 1) transmits a data delivery indicator (MOB-FWD-IND) to the mobile station. Accordingly, the mobile station receiving the data delivery indicator (MOB-FWD-IND) performs the procedures for resetting the IP address after receiving the data currently received. When informing the new base station about whether or not there are data to be delivered: Figure 16 represents an example of the procedures for the service base station to transmit an indicator and deliver data according to the request of an indicator explicit of the mobile station. Referring to Figure 16, when the mobile station that was receiving the data moves, and when the new base station (BS # 2) receives from the previous base station (BS # 1) delivery data for the terminal be transferred, the new base station (BS # 2) informs this fact to the mobile terminal when the telemetry procedures are carried out, after the mobile terminal is transferred, or when the registration procedures are carried out, in such a way that the mobile terminal differs the establishment of the IP address.

As described above, when the mobile terminal moves from a zone of a first base station in which an initial unoccupied transition was made, to an area of a second base station, and attempts to receive data, the present invention defines the procedures for delivering the data received from the first base station to the second base station, and defines a method for the mobile terminal to defer the IP address setting procedures to receive the data identified above, to efficiently perform the delivery of data. Also, the present invention provides the mobile terminal with a method for delivering data between base stations after a handover, and delaying the restoration of the IP address when the mobile terminal receives the data that was delivered from the previous base station to the new base station, in such a way that the continuity of the service can be guaranteed. As the present invention has been described with respect to wireless access techniques, it can be clearly understood that various wireless access techniques currently in development (such as WiMax, WiBro, Wi-FI, etc.) can also benefit from the features and teachings of the present invention, which are applicable due to the similarity involved in wireless communications involving mobility of the user's terminal, handoffs and idle mode operations. The foregoing description of the preferred embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these modalities will be apparent to the person skilled in the art, and the generic principles defined herein can be applied to other modalities. In this manner, the present invention is not considered to be limited to the modes shown, but is considered to be within the broadest scope consistent with the principles and novel features described herein.

Claims (41)

NOVELTY OF THE INVENTION CLAIMS

1. - A handover method for broadband wireless access systems, comprising: determining that handover is necessary for a mobile station while there is a session connection between end users; notifying from a first point of attachment to a second point of attachment that the session will be maintained by the second point of attachment after the handover; perform handover procedures by means of a mobile station to associate with the second point of attachment; reporting from the second point of attachment to the mobile station that there is a downlink data pending element of a mobile station; and if it is required to change the Internet Protocol address assignment, delay the assignment of the Internet Protocol address after receiving the pending downlink data element.

2. The method according to claim 1, further characterized in that the determination step is performed by the mobile station or by a network entity.

3. The method according to claim 1, further characterized in that the information step is omitted if the mobile station has a chronometer that is appropriately programmed to allow the mobile station to wait and receive any downlink data to be issued by the mobile station. the second point of union.

4. - The method according to claim 1, further characterized in that the delay step is performed by the mobile station.

5. The method according to claim 1, further characterized in that it comprises the steps of: performing a new assignment of the Internet Protocol address or resetting an Internet Protocol address by means of the mobile station; and instruct by means of the first point of attachment to the second point of union so that it finishes its resources to issue data.

6. The method according to claim 1, further characterized in that the mobile station associated with the second point of attachment refers to the entry or re-entry of the mobile station to the network.

7. The method according to claim 1, further characterized in that the handover procedures include telemetry and registration.

8. The method according to claim 1, further characterized in that the session includes the forwarding of data to the mobile station by the second junction point.

9. The method according to claim 1, further characterized in that the point of attachment is a base station, a router, or other type of access point.

10. The method according to claim 9, further characterized in that the first point of attachment is a base station previously in service and the second point of attachment is a new base station in service.

11. The method according to claim 1, further characterized in that the procedures are performed within a broadband wireless access system.

12. The method according to claim 1, further characterized in that the procedures are performed between multiple broadband wireless access systems.

13. The method according to claim 12, further characterized in that the multiple broadband wireless access systems comprise an IEEE network and a cellular network. 14.- A handover method for broadband wireless access systems, comprising: determining that a handover is necessary while there is a session connection between end users; reporting via a mobile station to a new junction point, to perform the release of the above attachment point with an indication of data issuance; notify from a previous junction point to the new junction point that the session will be maintained by the new junction point after the transfer; carry out the handover procedures by means of the mobile station to associate with the new point of attachment; reporting from the new point of attachment to the mobile station that there is a downlink data pending element of a mobile station; and if it is required to change the Internet Protocol address assignment, delay the assignment of the Internet Protocol address after receiving the pending downlink data element. 15. The method according to claim 14, further characterized in that it comprises, before the notification step, an information step carried out by the previous connection point, with respect to whether the data transmission can be sustained by it. 16. The method according to claim 14, further characterized in that the determination step is performed by the mobile station or by a network entity. 17. The method according to claim 14, further characterized in that the information step is omitted if the mobile station has a timer that is appropriately programmed to allow the mobile station to wait and receive any downlink data to be issued by the mobile station. the second point of union. 18. The method according to claim 14, further characterized in that the delay step is performed by the mobile station. 19. The method according to claim 14, further characterized in that it comprises the steps of: performing a new assignment of the Internet Protocol address or restoring an Internet Protocol address via the mobile station; and instruct by means of the first point of attachment to the second point of union so that it finishes its resources to issue data. 20. The method according to claim 14, further characterized in that the mobile station associated with the second junction point refers to the entry or re-entry of the mobile station to the network. 21. The method according to claim 14, further characterized in that the handover procedures include telemetry and registration. 22. The method according to claim 14, further characterized in that the session includes the forwarding of data to the mobile station by! second point of union. 23. The method according to claim 14, further characterized in that the point of attachment is a base station, a router or other type of access point. 24. The method according to claim 23, further characterized in that the first junction point is a base station previously in service and the second junction point is a new base station in service. 25. The method according to claim 14, further characterized in that the procedures are performed within a broadband wireless access system. 26.- The method according to claim 14, further characterized in that the procedures are performed between multiple broadband wireless access systems. 27. The method according to claim 26, further characterized in that the multiple broadband wireless access systems comprise an IEEE network and a cellular network. 28.- A transfer method for broadband wireless access systems, comprising: if a mobile terminal that receives downlink data moves from a region served by a first base station to a region served by a second base station; base, the first base station sends the downlink data to the second base station, and the second base station informs the mobile terminal that the downlink data must be sent to the mobile terminal. 29. The method according to claim 28, further characterized in that it comprises the steps of: deferring the establishment of the Internet Protocol address in the mobile terminal to allow the downlink data to be received by the mobile terminal. 30. The method according to claim 28, further characterized in that the information is achieved using a registration response message or a telemetry response message. 31. The method according to claim 30, further characterized in that the registration response message includes a parameter that differs from the establishment of the Internet Protocol address of the mobile terminal, indicating that there is downlink data to be available. issued. 32.- The method according to claim 28, further characterized in that it comprises: asking the first base station whether downlink data can be sent to the second base station by delivering a handover indicator via the mobile terminal to the first base station; informing the mobile terminal of the first base station, by means of a data delivery indicator, if possible the sending of data, and sending the downlink data to the second base station; and performing the Internet Protocol reset procedures after receiving the downlink data of the second base station upon receipt of the data delivery indicator. 33.- The method according to claim 32, further characterized in that if the first base station can not explicitly report its data dispatch capacity, or if the data delivery indicator is not received in a predefined time, the terminal Mobile makes an initial entry to the network, waits for some time the arrival of downlink data, and then performs the procedures for resetting the IP. 34.- The method according to claim 32, further characterized in that the data issuing indicator is a 2-bit operation code that indicates that the forwarding of data is possible or that the forwarding of data is not possible. The method according to claim 28, further characterized in that it comprises: issuing a handover indicator by means of the mobile terminal to the first base station; issue the downlink data for the first base station to the second base station, by means of a data delivery indicator; informing the mobile terminal by means of the first message that the second base station has data to be sent to it; and deferring the restoration of the IP by the mobile terminal during a certain period according to the first message, and receiving the downlink data of the second base station. 36. The method according to claim 35, further characterized in that the first message is a registration response message or a telemetry response message. 37. The method according to claim 35, further characterized in that the handover indicator indicates a release of the first base station. 38.- A method for maintaining data reception during mobility in broadband wireless access systems, comprising: performing a handover with a first base station and a second base station, while receiving downlink data from the first base station; receiving an indication that the second base station will issue additional downlink data related to the downlink data previously received from the first base station; delay the establishment of the Internet Protocol address until the additional downlink data is received; and receiving the additional downlink data of the second base station. 39. The method according to claim 38, further characterized in that it comprises, after receiving the additional downlink data, a step of restoring connectivity to the Internet Protocol after the establishment of the Internet Protocol address. 40.- A method for maintaining data transmission during mobility in broadband wireless access systems, comprising: performing a handover for a mobile station with a first base station and a second base station, while sending data downlink from the first base station to the mobile station; sending an indication to the mobile station that the second base station will issue additional downlink data related to the downlink data previously sent from the first base station; and sending the additional downlink data of the second base station to the mobile station which delayed the establishment of the Internet Protocol address until the additional downlink data is fully received. 41.- The method according to claim 40, further characterized in that after sending the additional downlink data, comprises a step of collaboration with the mobile station for the restoration of connectivity to the Internet Protocol, after the establishment of the Internet Protocol address.