Base station, mobile station, communication system and reordering method

FIELD: radio engineering, communication.

SUBSTANCE: data are sent from a handover source base station to a mobile station notifying that transference of packets has been executed during execution of handover sequence if the handover source base station transfers to the target handover base station packets which were not sent to the mobile station, from packets received from a host station, and the target handover base station sends packets to the mobile station. The mobile station reorders the received packets if transference of packets has been executed.

EFFECT: reduced communication delay and high capacity of the network during handover.

4 cl, 29 dwg

The technical FIELD TO WHICH the INVENTION RELATES.

[0001] the Present invention relates to a base station, mobile station, communication system and method for reordering, and more precisely to the base station, mobile station, communication system and method for reordering in which of the base station in the mobile station sends packets with attached rooms, indicating their sequence, and the mobile station is reflow these packets according to the sequence numbers.

The LEVEL of TECHNOLOGY

[0002] In mobile communication systems entered service CDMA-based third generation, but currently, in 3GPP (Third Generation Partnership Project (partnership project third generation)) consider a mobile communication system of the next generation (LTE: Long Term Evolution (long term development of communication networks)that provide the opportunity for faster communication (see non-patent document 1). In such systems, in addition to the increase in transmission speed, the main objective is to reduce the transmission delay.

To increase the transmission speed and reduce latency in the communication system of LTE attempts were made to speed up the processing of handover compared to conventional systems. In the case of mobile communication, if the communication mobile station PE elsaelsa, base station that performs communication with a mobile station, switch to another base station according to the receiving status. This is called handover, and the base station, generating a communication to handover, called “the source base station of handover”, and the base station, making the exchange of data after handover is called the “target base station of handover”. Therefore, the acceleration of handover absolutely necessary for the realization of high-speed/low-latency data transmission. In the LTE communication system, which is based on a system of exchange of packets, as handover used hard handover. In the case of hard handover line between the mobile station and the target base station of handover connects after separation line between the mobile station and the source base station of handover. Hard handover can be done quickly by receiving system information from the target base station of handover directly before handover, but during handover is interrupted user data.

This means that to reduce the transmission delay, it is important to reduce the status of the interrupt transmission and prevent packet loss during the interrupt status of the transfer. If during the interrupt status transmit packets is yli lost the lost packets restore using end-to-end retransmission, increasing, thus, the transmission delay.

[0003] Therefore, during handover in the LTE communication system, standardized is the way in which the source base station of handover moves to the target base station of handover, in addition to data, at least the packets including control information and the packet addressed to the mobile station (see non-patent document 2). However, the move whether the data is actually or not depends on whether this function.

[0004] Fig is a diagram illustrating the movement of the packages during handover. On Fig(A) two base stations 1a and 1b are connected to the host station 2 (e.g., access gateway). The mobile station 4 is located in the cell 3a of the base station 1a and currently performs communication with the base station 1a. In this case, if the mobile station 4 moves toward the base station 1b and included in the honeycomb 3b, as shown in Fig(B), is handover, and the base station communication of the mobile station is switched from the base station 1a to the base station 1b. The base station, generating a communication to handover, called “the source base station of handover” (source base station)and a base station, which produces currency Yes the bag after handover, referred to as the target base station of handover” (target base station).

The source base station 1a of handover stores the packets received from the host station 2, in the internal buffer and sequentially sends stored in the buffer packets for the mobile station 4. Therefore, during execution of handover some stored packets remain in the buffer is not sent to the mobile station. On Fig(B) n-2-th to n-th packets that were received before handover and have not yet been sent to the mobile station are in the buffer, and these packages after handover must be sent from the target base station 1b of handover in the mobile station 4. Therefore, after performing the sequence of handover the source base station 1a of handover moves (forward) n-2-th to n-th packet to the target base station 1b of handover (this is called forwarding). When using this method of forwarding, in which the target base station 1b of handover sends these packets to the mobile station 4 immediately after handover, the packet transmission is not interrupted. Thus eliminating the need for end-to-end re-transmission of packets, and can be made high handover. The above-mentioned n-2nd - nth are numbers that indicate the sequence of packets (the number in the sequence).

[0005] Fig depict is to place a chart, to illustrate handover in the LTE communication system, and Fig is a flow diagram illustrating the procedure of handover, which is adopted in the LTE communication system in the present time.

Mobile station (UE) 4 notifies the source base station 1a of handover that the necessary handover HO, using the message about the measurement (1. The management dimension).

The source base station 1a of handover selects the target base station 1b, based on the content of the message about the measurement (2. The decision regarding HO), and sends this to the target base station 1b of handover the request for handover (3. Request for HO). HO means handover. At this time, the source base station 1a of handover also sends information about the mobile station (for example, information about ID and QoS (quality of service) mobile station to the target base station of handover. Based on this information, the target base station 1b of handover performs admission control call (4. Admission control call).

If the target base station 1b of handover allows the reception of the mobile station, it returns to the source base station of handover response relative to handover (5. The answer is relatively HO). Further, the source base station 1a of handover gives the mobile station 4 instruction on handover (6. Statement regarding HO), then before or after this step, the part is no movement of data (packets) (moving packets: redirect).

The mobile station 4, which received instruction on handover, provides synchronization with the target base station 1b of handover using L1/L2 signaling (7. Ensuring synchronization), and, when synchronization is established, the mobile station 4 sends to the target base station 1b of handover completion message of handover (8. Complete HO).

Thus, the target base station 1b of handover sends to the host station 2 completion message of handover (9. Complete HO). The host station 2, which has received the message about the completion of handover, switches the transmission path of packets from the source base station 1a of handover to the target base station 1b of handover (10. Switching the way), and returns the completed response in HO target base station 1b of handover (11. The completed response HO). Using the completed response HO target base station 1b of handover informs the source base station 1a of handover about the end of handover HO (12. Release resources). Then the path between the source base station 1a of handover and the host station 2 is 13. Release resources).

[0006] If the movement of packets (forwarding) occurs during the execution of the above sequence of handover roaming packages can be ahead of the packages that are in the target base station 1b of handover from the host stations is 2, and a sequence number can be disordered. If the target base station 1b of handover moves the packets to the mobile station 4 without restoring order, the mobile station will not be able to receive packets in the correct order, which leads to deterioration of communication quality, and the result will not be able to be made of high-quality communication before and after handover.

Therefore, in the LTE communication system according to the sequence of packets between the base station and the mobile station supports the following way. Fig is a diagram illustrating the matching of the sequence of packets on which the target base station 1b of handover supports compliance of the sequence of packets, transmitting the packets transferred from the source base station 1a of handover, with a higher priority than the packets received from the host station. In other words, n-5 - n-th packets were stored in the source base station 1a of handover to run handover, then runs handover, so n-5 - n-3 packages are moved to the target base station 1b of handover and stored in the buffer BF. In the buffer BF of the target base station 1b of handover also stored n+1 and n+2-th packets received from the host station.

The target base station 1b of handover that stores moved n-5 - n-3 package is and n+1 and n+2-th packets, that were transferred to the buffer from the host station first sends to the mobile station n-5 - n-3 packets transferred from the source base station 1a of handover. Then, when there is a delay while moving n-2-th - the n-th packet from the source base station 1a of handover target base station 1b of handover sends to the mobile station n+1 and n+2-th packets. Mobile station 4 performs the processing for percompany received packets according to the sequence numbers (reordering).

[0007] Fig is a flow diagram illustrating the processing of reorderings in the mobile station. On Pig mobile station 4 receives n-5 - n-3 packets according to the sequence numbers, thus on the upper level, the packages are moved sequentially. However, when receiving the n+1-th and n+2-th packet n-2-th to n-th packet is not yet received. Therefore, the mobile station 4 stores n+1 and n+2-th packet in the buffer BF1 to obtain n-2-th - the n-th packet, which has not yet been received, and does not move n+1 and n+2-th packet to the upper level. After receiving n-2-th - the n-th packet of the mobile station 4 moves these packages and n+1 and n+2-th packet to the upper level consistently. Typically, for a time-out packages install upper limit, which is measured, for example, a timer of the mobile station.

As mentioned above, in the case of the AE of handover in the LTE communication system, the main methods are moving packets (packet forwarding) from the source base station of handover in the target base station of handover and processing reorder packets at the mobile station. The relationship of these functions are described in more detail below.

[0008] Fig is a block diagram illustrating the configuration of a Protocol between the mobile station and the network. Between the mobile station and the network install at least the level of the PDCP (Packet Data Convergence Protocol convergence packet)), RLC (Radio Link Control radiotuna)) and lower level (level MAC/ physical layer MAC/PHY). All these levels are set in the mobile station, but not always installed in the station from the network. In the case of the example shown in Fig, level PDCP installed on the host station aGW2, and the RLC level and the lower level is installed in the base station 1. The system can be configured so that the levels of the PDCP, RLC and the lower level were installed in the base station 1, and only simple functions such as a function of packet routing and function of the accession numbers in the sequence are provided in aGW2.

[0009] In the case of the example shown in Fig, at the level of the PDCP data are exchanged between the mobile station 4 and aGW2, which is the host station, and at the level of the RLC is going on is it the exchange of data between the user terminal 4 and the base station 1.

In other words, addressed to the mobile station the data received from the upper level (e.g., IP layer) first level PDCP and become PDCP SDU (block data services), then adds the header information (for example, a sequence number in the PDCP level), and generates a PDCP PDU (Protocol data unit).

PDCP PDU is sent to the RLC level, where it becomes RLC SDU, then added the header information (for example, number in the sequence-level RLC), and generated RLC PDU. RLC PDU arrives at the RLC level of the mobile station through the processing at the lower level. At the level of the RLC header is removed and restored RLC SDU, then at the level of the PDCP removes the header of the PDCP PDU and generates a PDCP SDU, which is sent to the upper level of the mobile station.

In this configuration Protocol, in the LTE communication system, the movement of the packets in blocks RLC SDU or in blocks PDCP SDU, and reordering occurs in blocks PDCP PDU. As the RLC SDU and PDCP PDUs are essentially the same data, in the present description, they are simply called "packages", and it is assumed that the number of the package described here indicates the number in the sequence PDCP PDU, unless otherwise noted.

[0010] Fig is a block diagram of the sequence of operations showing the operation of the device and the source base station of handover in premachandra.

When the source base station 1a of handover receives from the mobile station 4 corresponds to the reception signal level with a message about the measurement (step 101), the source base station 1a of handover assesses whether handover HO (step 102), and if non-required, returns to the beginning.

If the decision is made about the necessity of handover, the source base station 1a of handover selects the target base station 1b of handover, based on the content of the message about the measurement and sends a request for handover in the target base station 1b of handover (step 103).

Then the source base station 1a of handover gets sent from the target base station 1b of handover response relative to handover (step 104), and evaluates whether the movement data (step 105). If the movement of packets sent to the mobile station and located in the buffer does not occur, the source base station 1a of handover sends to the mobile station instruction on HO and remove these packages (step 106). On the other hand, if the movement of packets sent to the mobile station and located in the buffer occurs, the source base station 1a of handover sends instruction on HO in the mobile station and forwards these packets to the target base station of handover (step 107). Relocation packages for services, will colorattribute processing in real time, such as a VoIP call fails and packets will be dropped. This is due to the fact that the reset packets ensures that the voice transmission and reception without delay. Relocation packages for services that require high QoS is performed.

Then the source station 1a of handover receives a message about the release of resources, which is sent from the target base station 1b of handover (step 108), and releases the resources (step 109).

[0011] Fig is a block diagram of the sequence, demonstrating the target base station of handover during handover.

When receiving the target base station 1b of handover request HO (including information about the ID and the QoS of the mobile station from the source base station 1a of handover (step 121), the target base station 1b of handover on the basis of this information, performs admission control call and evaluates permitted or not the reception of the mobile station (step 122). If no permit, the target base station 1b of handover performs subsequent processing (step 130), and finishes the control handovers.

On the other hand, if the receiving mobile station is allowed, the target base station 1b of handover returns the response relative to the HO in the source base station 1a of handover (step 123). Then the target base station 1b of handover stores in the buffer is moved from its original basic is th station 1a of handover packets (step 124), and receives from the mobile station 4 a completion message HO (step 125). When a message is received on completion of the HO target base station 1b of handover sends a completion message to the HO in the host station 2 (step 126). When a message is received on completion of handover the host station 2 switches the transmission path of packets from the source base station 1a of handover to the target base station 1b of handover and returns the completed response in HO target base station 1b of handover (step 127). When receiving from the host station 2 completed response HO target base station 1b of handover starts sending from the target base station 1b of handover in the mobile station mainly forwarded packets, as received from the host station 2 starts sending packets to the mobile station after sending the packages mentioned above (planning: step 128). In parallel with step 128 mobile target base station 1b also sends a message about releasing resources in the source base station 1a of handover (step 129), and performs the subsequent processing (step 130), and finishes the control handovers.

[0012] Fig is a block diagram of the sequence, demonstrating the mobile station during handover.

Mobile station 4 notifies the source base station of handover relating to the reception level of the signal using the communication is the communication about the measurement (step 151). Then the mobile station 4 expects from the source base station 1a of handover instructions on HO and when it is received (step 152), the mobile station 4 provides synchronization with the target base station 1b of handover with alarm L1/L2 (step 153), and when establishing synchronization sends a message about the completion of handover in the target base station 1b of handover (step 154). Then, if the target base station 1b of handover received packets, the mobile station performs the processing reorder (steps 155-160).

In other words, when receiving from the target base station 1b of handover packet of the lower level control unit of the mobile station generates an RLC SDU and directs this RLC SDU block reordering (step 155). Block reorder checks whether continuous numbers in the sequence (step 156), and sends this RLC SDU to the upper level in the form of a PDCP SDU, if a sequence number is continuous, i.e. no gaps separate rooms (step 160). On the other hand, if a sequence number RLC SDU is interrupted, the unit reorder stores the RLC SDU (=PDC PDU) (step 157) and then checks, resumes or no continuity of sequence numbers by using the received RLC SDU (step 158). If the continuity of sequence numbers is resumed using the LC SDU, the unit sends reorder this RLC SDU to the upper level in the form of a PDCP SDU, and then directs to the upper level stored RSC SDU (=PDCP PDU) (step 160).

At step 158, if a sequence number of the received RLC SDU are not continuous, the mobile station monitors has expired if the specified time (step 159), and, if time has not expired, after step 157 repeats the processing, or if the time has expired, sends the stored PDCP PDU to the upper level, even if the numbers in the sequence are not continuous (step 160).

[0013] In the LTE communication system has the following problem related to the transmission of packets during handover. That is, during execution of handover in the LTE communication system moving intended for the mobile station of packets remaining in the source base station 1a of handover, is performed by the above mentioned method, thanks to which the packages are moved to the target base station of handover (forwarding). However, did move packages at the time of handover depends on whether this function move the source base station of handover.

As a result, even if the source base station 1a of handover has not complied with the movement of packets (packet forwarding), the mobile station 4, which was not notified, you may determine that the movement of the packages was performed, and in this case, p is, after the close of handover control block reordering in the mobile station must wait even if this is not necessary, packets arrive with a continuous sequence numbers within a specified amount of time. This increases the latency of communication, poor capacity and lack of opportunities for maintaining good communication before and after handover.

[0014] In Fig shows an example of n-2-th - the n-th packets remaining in the source base station 1a of handover. If these packets were not forwarded to the target base station 1b of handover, after receiving the n+1-th packet from the target base station 1b of handover mobile station 4 should be expected, even if this is not necessary, the arrival of n-2-th - the n-th packet, which will never be sent within a specified time. The result is delay, and the decrease in throughput of the entire system.

The first available prior art is a device reflow and reorder, which restores the packets to the fact that they had to fragmentation of fragmented packets, and corrects the violation sequence of arrivals of packets to restore the original sequence (patent document 1). However, this prior art relates to the reflow device and reorder, which restores the item is chum salmon prior to their fragmentation from fragmented in GTP tunnel packet (GTP: GPRS Tunneling Protocol (GPRS tunneling Protocol)) for GPRS (General Packet Radio Service (General packet radio use)restores caused by fragmentation violation of the sequence of packets and performs rearrangement in the source sequence.

The second available prior art is a mobile communications system that implements high-speed transmission of data packets without data loss during handover between base stations in high-speed packet data (patent document 2). In this mobile communication system in the implementation of handover between base stations in accordance with the state of the mobile station, the source base station of handover moves (forward) packet data to the target base station of handover during high-speed packet data between a base station and mobile station.

However, neither the first nor the second preceding technologies do not solve the problem of increasing the latency of communication or reduction of throughput in the reordered result received from the target base station of handover packages.

[0015] Given the above, the present invention is that during the control handover mobile station shall not perform perepa adouane packets according to the order of sequence numbers (even if they are not contiguous), if remaining in the source base station of handover packets were not forwarded to the target base station of handover (the move was not implemented).

Another objective of the present invention is to perform a reorder packets according to the sequence numbers of the mobile station during the control handovers in if remaining in the source base station of handover packages were forwarded to the target base station of handover (the move was made).

[patent document 1] published patent application of Japan No. JP2004-135076A

[patent document 2] published patent application of Japan No. JP2004-282652A

[non-patent document 1] 3GPP, “Requirements for Evolved UTRA (E-UTRA) and Evolved UTRAN (E-UTRAN)”, TR25.913 V7.3.0, Vol. 7, March 2006

[non-patent document 2] 3GPP, “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN)”, TS36.300, Vol. 8, so 4.0, January 2007

The INVENTION

[0016] the Method reorder

The first aspect of the present invention is a method of rearranging to send packets with attached numbers indicating the sequence of the base station in the mobile station, and rearranging the packets in the mobile station according to the sequence numbers. This method reorder includes: a first step of sending data to notify the MoE is strong station about during the sequence of handover the packages move was made, if the source base station of handover moves to the target base station of handover packets that were not sent to the mobile station, received from the host station of the packets and the packets are sent from the target base station of handover in the mobile station; a second step of sending data to notify the mobile station that the movement of the packages during the execution of a sequence of handover was not performed, if the packages are not moved to the target base station of handover; and the third step of the reorder received packets at the mobile station, if the packages move was made.

In the third stage of the present invention, the reorder processing terminates if the packages with continuous numbers in the sequence are received, even if the processing reorder received packets occurs within a specified time.

Way to reorder the present invention further comprises a decision point or a need to move to the target base station of handover packets that were not sent to the mobile station, or about the necessity of their removal, including the link state information of the target base station of handover, p is obtained from the target base station of handover during the execution of a sequence of handover.

Way to reorder the present invention further comprises a decision point, depending on the type of service, or about the need to move to the target base station of handover packets that were not sent to the mobile station, or about the necessity of their removal.

If the numbers indicate the sequence of packets attached to the packages in the base station, the numbers attached to packets that were not sent from the source base station of handover in the mobile station are communicated to the target base station of handover while moving packets to the target base station of handover.

[0017] the communication System

The second aspect of the present invention is a communication system to send packets with attached numbers indicating the sequence of the base station in the mobile station, and rearranging the packets in the mobile station according to the number in the sequence. This communication system includes a source base station of handover, the target base station of handover and the mobile station, and (1) the source base station of handover has: a buffer for storing packets received from the host station; a transmission unit of packets to send to the mobile station stored in the packet buffer; and a control unit, which sends the data to notify the MoE is strong station about the packages move was made, if the sequence of handover the source base station of handover moves to the target base station, the packets that were not sent to the mobile station, and sends the data to notify the mobile station that moves packets to the mobile station is not performed, if the movement of packets to the target base station of handover not performed, (2) the target base station of handover has: a buffer which stores packets received from the source base station of handover, and packets received from the host station when performing a sequence of handover; a control unit that performs control so that the mobile station went mainly the packets received from the source base station of handover; and a transmission unit that sends the packets to the mobile station, and (3) the mobile station has: a buffer which stores packets received from the base station; and a control unit, which reorder the received packets or not reorder the received packets based on the data received from the source base station of handover and indicates whether the movement of the packages.

The control unit of the source base station of handover make a decision either about having to move in Zelenoglazoe station of handover packages which were not sent to the mobile station, or about the necessity of their removal, including the link state information of the target base station of handover received from the target base station of handover executing a sequence of handover.

Depending on the type of service the control unit of the source base station of handover make a decision either on the need to move packets that were not sent to the mobile station, the target base station of handover, or about the necessity of their removal.

[0018] the base station

The third aspect of the present invention is a base station in the communication system to send packets with attached numbers indicating the sequence of the base station in the mobile station and reflow in a mobile station of a packet according to the number in the sequence, comprising: a buffer for storing packets received from the host station, and packets received from the source base station of handover executing a sequence of handover; block packet that sends the mobile station the packets stored in the buffer; a control unit handover, which takes a decision either about having to move packets that were not sent to mobile station, the target base station of handover when performing the pic is egovernance of handover, or about the absence of such necessary, moves the packets to the target base station of handover and data for notifying the mobile station that the packages move was made for the need to move packets to the target base station of handover, and sends the data to notify the mobile station that the packages move was not made in the absence of the need to move packets to the target base station of handover; and a transmission control block, which when executing a sequence of handover sends the mobile station the packets received, the source base station of handover, with a higher priority than the packets received from the host station.

[0019] the Mobile station

The fourth aspect of the present invention is a mobile station in the communication system to send packets with attached numbers indicating the sequence of the base station in the mobile station and reflow in a mobile station of a packet according to the number in the sequence, comprising: a buffer for storing packets received from the base station; and a control unit that makes a decision either about the need for reordering the packets received from the target base station of handover, or about the absence of such necessary, based on the data floor is received from the source base station of handover executing a sequence of handover and indicates, was it made moving packages. The control unit terminates the processing reorder, if packets with continuous numbers not obtained, even if the processing reorder received packets occurs within a specified time.

BRIEF DESCRIPTION of DRAWINGS

[0020] Figure 1 is a diagram illustrating a first variant implementation;

Figure 2 shows examples of the format of the response messages regarding HO, including information about the link state;

Figure 3 is a block diagram of a base station;

Figure 4 is a block diagram of the mobile station;

Figure 5 is a block diagram of the sequence of operations illustrating operation of the target base station of handover according to the first variant of implementation;

Figure 6 shows an example of a message format instructions on HO;

7 is a block diagram of the sequence of operations illustrating operation of the source base station of handover according to the first variant of implementation;

Fig is a block diagram of the sequence of operations illustrating a mobile station according to the first variant of implementation;

Fig.9 is a block diagram illustrating the processing of reorder mobile station;

Figure 10 is a diagram which, illustrating a second variant implementation;

11 is a block diagram of the sequence of operations illustrating operation of the source base station of handover according to the second variant of implementation;

Fig is a block diagram of the sequence of operations illustrating operation of the source base station of handover according to one of embodiments;

Fig is a block diagram illustrating the processing of reorder mobile station according to one of embodiments;

Fig is a block diagram of the base station, the control unit buffer which has a simplified configuration without features travel packages;

Fig is a block diagram of the sequence of operations illustrating operation of the source base station of handover according to the third variant of implementation;

Fig is a block diagram of the system, which focuses on the levels;

Fig is a diagram illustrating a fourth option implementation;

Fig is a flow diagram illustrating the procedure of handover fourth variant implementation;

Fig is a diagram illustrating the movement of the packages during handover;

Fig represents a diagram, and lusterous handover in the LTE communication system;

Fig is a flow diagram illustrating the procedure of handover, which is adopted in the LTE communication system at the present time;

Fig is a diagram illustrating the matching of the sequence of packets;

Fig is a flow diagram illustrating the processing of reorder mobile station;

Fig is a diagram illustrating the configuration of a Protocol between the mobile station and the network;

Fig is a diagram illustrating the case when the PDCP installed in aGW, which is the host station, and the RLC level and the lower level is installed in the base station;

Fig is a block diagram of the sequence of operations illustrating the operation of the device and the source base station of handover during handover;

Fig is a block diagram of the sequence of operations illustrating operation of the target base station of handover during handover;

Fig is a block diagram of the sequence of operations illustrating operation of the mobile station during handover; and

Fig is a diagram illustrating problems of the prior art,

The BEST WAY of carrying out the INVENTION

[0021] (A) the Principles underlying the present invention

the present invention the problem is solved by providing opportunities for base station and mobile station to perform the following two procedures.

Procedure 1: During handover the source base station of handover or the target base station of handover with information about the move notifies the mobile station of whether or not been transferred data.

Procedure 2: When receiving information about the move on the basis of this information, the mobile station evaluates whether the movement data, and if data movement is not done, then the mobile station does not reorder the arrived packets, and immediately after receiving them sends these packets to the upper level.

In the conventional method, the source base station of handover does not provide information of the mobile station on the move during handover. Therefore, even if data movement is not performed, and thus, is not forwarding packets from the source base station of handover in the target base station of handover, the mobile station must wait neperechislenie packages, even if it is not required, until then, until a specified time, which increases the latency of communication and poor throughput. However, if the mobile station receives information about the move according to the method of the present invention, it may know, running or not moving data, and if PA is Yety were not forwarded, the reordering can be stopped, so you can avoid unnecessary attempts to reorder packets. In the result before and after handover can be stored more high quality than by the usual method.

[0022] (B) the First option exercise

Figure 1 is a diagram illustrating a first variant implementation, in which the source base station 11a assesses the ability to move packets (packet forwarding)from the state of the connection target base station 11b of handover executing a sequence of handover, and provides the mobile station 14 for information on performing forwarding (information transfer is performed).

In figure 1, when the start sequence of handover, n-2-th to n-th packet addressed to the mobile station are stored in the buffer BF of the source base station 11a of handover, and n-2-th packet is transmitted to the mobile station, but the transfer of this n-2-th packet is not completed. During the execution of a sequence of handover target base station 11b of handover sends information about the state of communication in the target base station of handover in the source base station 11a of handover along with the message-response relative to HO. When receiving the link state information of the source base station 11a of handover decides, mo is et to be performed by the data transfer based on the communication status of the target base station 11b of handover, and instructions on HO attaches information about the move, which indicates, running or not moving data, and sends it to the mobile station 14.

[0023] figure 2 shows an example of the format of the response messages regarding HO, including information on the status of the link. This message includes at least the ID and the CST information about the connection status, as shown in figure 2(A). The identifier may be included a new identifier that the mobile station uses at least during the communication with the target base station of handover. It can also include the address of the source base station 11a of handover as the destination address of this message and the address of the target base station 11b of handover may be included as the source address of the transmission of this message. If the status information of the communication presents X bits, then the number of States that can be specified is 2^X.

As shown in figure 2(B), CST information about the status of the link has information on the degree of congestion according to the degree of overload of the target base station 11b of handover. For example, if information about the degree of congestion is represented by two bits, can be represented by four degrees p is regusci (dangerous overload, severe congestion, easy overload no overload). On the other hand, CST information about the communication status may include information about the state of the buffer to provide information about the amount of free memory in the target base station of handover, as shown in figure 2(C). For example, the status information of the buffer consists of 10 bits, in this case can be represented 1024 States. If the unit of this value is in kilobytes, you can imagine that the mobile station is reserved for a maximum of 1024 kilobytes of memory. In addition, CST information about the communication status may include information about the installation in the target base station of handover moving packages, as shown in figure 2(D). This information about installing the displacement is information to indicate whether it was or not installed, the function of moving packages. For example, to move the packets from the source base station 11a of handover in the target base station 11b of handover required Protocol to move packages (travel packages). Information about what was installed or not such a function can be represented in 1 bit, and using this bit source base station 11a of handover notified about installing this feature.

After getting the source base station 11a handov the RA information messages about the overload condition is evaluated the ability to move data. For example, when notifying the target base station 11b of handover about “light congestion” data movement is performed. When notifying the target base station 11b of handover about “excessively” moving data is not performed. On the other hand, if the amount of free memory in the target base station 11b of handover is sufficient to save all roaming packages, the data movement is performed. When the notification that the amount of free memory in the target base station 11b of handover is "0 kilobytes", data movement is not performed. Moreover, the data move occurs, if the target base station 11b of handover set function move packages. When the notification that the function of moving packages are not installed, the data movement is not executed.

[0024] Figure 3 is a block diagram of a base station, which shows the buffer block 21, block 22 scheduler unit 23 of the transmission and reception unit 24 of the control.

The buffer block 21 is a memory for storing packets received from the host station, and a packet transferred from the neighboring base station (source base station of handover). Figure 3 the base station is physically has two buffers, but can have one physical memory divided by software to provide the Deposit. Block 22 scheduler from among multiple mobile stations in the network selects a mobile station, which performs radio transmission, extracts the packets of the mobile station stored in the block buffer, and sends them to the block 23 of transmission/reception. Unit 23 of the transmission/reception encodes and modulates received from the scheduler packets and transmits them by radio. Unit 23 of the transmission/reception also receives and demodulates control signals and various data sent from the mobile station.

Unit 24 of the control unit 24a of the control buffer unit 24b management HO and block 24c of the control information about the measurement. Block 24a buffer management manages different packets stored in the buffer 21. If during handover moves data stored in the buffer block 21, the packages are moved to the target base station of handover. On the other hand, if the data movement does not occur, even at the start of handover, block 24a buffer management ensures that all stored in the buffer block 21 packages have been removed. Unit 24b management HO manages handovers that illustrated in Fig, and the block 24c of the control measurement collects various information about the measurements, which is sent from the mobile station, such as the communication quality CQI (Channel Quality information as the channel is)) the mobile station.

[0025] Figure 4 is a block diagram of a mobile station, which shows the block 31 of the transmission/reception unit 32 of the buffer unit 33 reorder and control unit 34. Unit 31 receiving/transmitting transmits/receives packets and control information to/from the power transmission/reception base station. If the RLC PDU can not be generated from the received packet of the lower level block 32 of the buffer to store the packets until will be generated RLC PDU if the RLC PDU can be generated, the block 32 buffer removes the header and sends the packet in block 33 rearrange in the form of RLC SDU (see Fig). The block 33 has a reorder function for reflow RLC SDU (=PDCP PDU) according to the sequence numbers and sends it to the upper level. Upon detection of the interruption of the continuity of sequence numbers RLC SDU (=PDCP PDU) unit 33 reorder stores next RLC SDU (=PDCP PDU) in the internal memory up until using the received RLC SDU is not resumed continuity of sequence numbers. If the RLC SDU (=PDCP PDU) is not received even after a predetermined time, the controller can reorder stops processing reorder and sends all stored PDCP PDU to the upper level.

The control unit 34 is a unit 34a of the control measurement, control unit 34b reordering and block 34c management popcorn the th transmission. Unit 34a management measurement performs the measurement, generating a variety of information about the measurements, which is intended for sending to the base station. For example, is a measure of the quality of radio communication CQI (channel quality) of the mobile station. Unit 34b management reordering manage unit 33 reorder, and if the continuity of sequence numbers PDCP PDU is broken, the unit 34b management rearranging gives an instruction unit 33 reorder to save PDCP PDU and the expectation of the PDCP PDU which renews the continuity of sequence numbers. After a specified period of time for waiting for the arrival of the package unit 34b management rearranging gives an instruction unit 33 rearrange to complete reorder, and remove the headers all stored PDCP PDU and sends them to the top level in the form of a PDCP SDU to provide opportunities for new PDCP PDU. During management of the re-transmission unit 34c control re-transmission sends signals to a request for retransmission to the base station using the block 31 of the transmission/reception, as shown by the dotted line.

When doing the redirect, according to Figure 1, the transfer of n-2-th batch is terminated, and the target base station 11b of handover move n-2-th to n-th packet is. On the other hand, if the packet forwarding fails, it stops the transfer of n-2-th packet, and n-2-th to n-th packet is removed from the block buffer BF. The source base station 11a of handover attaches to the message-instructions on HO to the mobile station 14 information about the move to indicate whether the data movement (forwarding data), and sends this message-instruction on HO.

[0026] Figure 5 is a block diagram of the sequence of operations illustrating operation of the target base station 11b of handover to perform a series of the aforementioned operations.

Figure 5, when the receiving unit 24b management handover target base station 11b of handover request HO (including information about the ID and the QoS of the mobile station from the source base station 11a of handover (step 201) unit 24b management handover controls the reception of the call, based on this information, and assesses whether the receiving mobile station (step 202). If the reception is not allowed, subsequent processing is performed (step 211) and the management handover completes.

On the other hand, if the receiving mobile station is allowed, the unit 24b management handover evaluates the status of the link (the overload condition, the usage status of the buffer or the status of installed functions) of the target base station 11b of handover (this is 203) and returns to the source base station 11a of handover the response message to the request for HO, including information about the connection status, which was described according to Figure 2 (step 204). Then you move data to the target base station 11b of handover stores in the buffer 21 packets forwarded from the source base station 11a of handover (step 124), and then the block buffer 21 stores the packets forwarded from the source base station 11a of handover.

If in this state the unit 24b management handover receives from the mobile station 4 a completion message HO (step 206), the unit 24b management handover sends a completion message to the HO in the host station 12 (step 207). When a message is received on completion of handover the host station 2 switches the transmission path of packets from the source base station 11a of handover to the target base station 11b of handover and returns a response of completion of the HO to the target base station 11b of handover (step 208). Upon receipt of the completed response HO from the host station 12 unit 24b management handover target base station 11b of handover gives an instruction scheduler 22 about the beginning of the packet. Thus, the scheduler 22 priority starts the transmission of the forwarded packets to the mobile station 14 and then after sending the above packet transmission is initiated by the mobile station, the packet received from the host station 12 (planning: step 209). In parallel with step 209, block 24b management is the Andover sends to the source base station 11a of handover message about the release of resources (step 210), performs subsequent processing (step 211), and terminates the management handover.

[0027] the Source base station 11a of handover using the above message instruction on HO, notifies the mobile station 14 about done moving data or not. 6 is an example of a message format-instructions on HO. This message includes at least the ID and information on the implementation of handover PH0. The identifier is included in at least a new identifier that the mobile station 14 uses to communicate with the target base station 11b of handover. The address of the mobile station 14 may be included as the destination address of this message and the address of the source base station 11a of handover may be included as the source address of the transmission of this message. In addition, to provide information about the move included at least one bit of information. For example, the value “0” of this information indicates that the movement of data (packet forwarding) was performed, and a value of “1” this information indicates that the data movement was not performed. On the contrary, a value of “0” can indicate that the data movement was not performed, and a value of “1” this information tells the, the data movement was executed.

[0028] Fig.7 is a block diagram of the sequence of operations illustrating the operation of the device and the source base station of handover to perform a series of the aforementioned operations.

7, when the receiving unit 24a of the control dimension is the user of the source base station 11a of handover received status information from the mobile station 14 using the message about the measurement (step 251), block 24a management dimension assesses whether handover HO from the received status information (step 252), and returns to the beginning when there is no need to handover.

If the decision is made about the necessity of handover HO, block 24b management handover determines the target base station 11b of handover, based on the content of the message about the measurement, and that the target base station 11b of handover sends a request to handover (step 253).

Then the unit 24b management handover receives the response message regarding HO, transmitted from the target base station 11b of handover (step 254), decides to run peremeny packets (packet forwarding), based on the CST information about the status of the link included in the response message regarding HO (step 255), and if the decision is made about the failure to move packages, unit 24b management HO enters information PH0 the transfer is performed (=“1”: the movement is not performed) in the message-instruction on HO, sends it to the mobile station (step 256) and gives an instruction unit 24a of the control buffer to remove packages that are stored in the buffer 21 (step 257).

On the other hand, when the decision at step 255 about moving packages block 24b management HO enters information PH0 on the move (=“0”: the move is performed in the message instruction on HO, sends it to the mobile station 14 (step 258) and gives an instruction unit 24a of the control buffer for forwarding to the target base station 11b of handover remaining in the buffer 21 of packets (packet forwarding) (step 259). Thus, block 24a of the control buffer is redirected to the target base station 11b of handover packets that were not sent to the mobile station 14 and remained in the buffer 21, indicated by the dashed line route. Then the unit 24b management HO gets sent from the target base station 11b of handover message about the release of resources (step 260) and releases the resources (step 261).

Figure 1 is a mobile station 14 receives information PH0 about the move included in the message instruction regarding HO, and starts rearranging, if the move was performed. In particular, in the case of receiving mobile station 14 n+1-th and later batches before n-2-th - the n-th packet of the mobile station 14 will arrive n-2-th - the n-th packet on the specified amount of time, not directing n+1-th packet to the upper level. On the other hand, if the move was not performed, the mobile station 14 immediately sends n+1-th and later packets to the upper level and prepares to receive the next packet without waiting for the arrival of the n-2-th - the n-th packet.

[0029] Fig is a block diagram of the sequence of operations illustrating operation of the mobile station.

Unit 34a of the control measurement of the mobile station 14 notifies the received state of the source base station 11a of handover using message about the measurement (step 271). Then, the control unit 34 waits for a message-instructions on HO, which is sent from the source base station 11a of handover, and if the message is the instruction on HO received (step 272), the control unit 34 provides synchronization with the target base station 11b of handover using L1/L2 signaling (step 273), and ensuring synchronization sends a message about the completion of handover in the target base station 11b of handover (stage 274). Then the control unit 34 checks whether the data movement (forwarding data), referring to information PH0 on the move message-instructions on HO obtained at step 272 (step 275), and if the movement of data was not performed, the control unit 34 implements control for generations the PDCP SDU, using the packets received from the target base station 11b of handover, and sends it to the upper level without performing the processing reorder (stage 276). On the other hand, if at step 275 is determined that the movement of data has been performed, the block 34b management reordering manage unit 33 reorder, and performs processing reorder (step 277).

[0030] Figure 9 is a block diagram illustrating the processing of reorderings in the mobile station.

When the receiving unit 31 of the transmission/reception of the packet of the lower level from the target base station 11b of handover, block 34b management reorder checks can be generated RLC PDU (step 302), and if he can not be generated, checks, expired, whether the set time (step 303), stores the packet of the lower level in the buffer 32 (step 304), and if the preset time has not yet expired, performs the processing after step 301. If the RLC PDU can not be generated, even after a predetermined time after receiving the packet of the lower level, the packet of the lower level is removed from the buffer (step 305).

On the other hand, if the RLC PDU can be generated using the packet of the lower level obtained at step 302, the block 34b management reordering directs this RLC PDU in block 33 rearrange in the form of RLC SDU (step 306). Upon receiving the RLC SDU b is OK 33 reorder checks is there a missing number in the sequence, confirms the continuity of sequence numbers (step 307), and sends the RLC SDU to the upper level in the form of RDCP SDU, if a sequence number is continuous, there are no missing numbers (step 311). However, if there is any missing number in the sequence, the unit 34b management rearranging gives an instruction unit 33 reorder to save RLC SDU (=PDCP PDU) (step 308). Thus, the block 33 reorder stores the RLC SDU (=PDCP PDU) in the internal memory and checks renewed if the continuity of sequence numbers by using the received RLC SDU (step 309). If the continuity of sequence numbers resumed using the received RLC SDU, the unit 33 sends reorder this RLC SDU to the upper level in the form of a PDCP SDU, and sends to the upper level of the stored RLC SDU (=PDCP PDU) (step 311).

If the RLC SDU, which renewed the continuity of sequence numbers, is not received at step 309, block 33 reorder checks, expired if the specified time (step 310), repeats the processing after step 308, if the time has not expired, or directs stored PDCP PDU to the upper level, if the time has expired, even if the numbers in the sequence are not continuous (step 311).

As described above, according to the first variant is sushestvennee, if not redirected packets remaining in the source station handover, in the target base station of handover when performing management handover (move fails), the mobile station does not need to perform reordering, even if the numbers in the sequence are not continuous, so is not generated excess waiting time can be minimized delay time data, and can be improved throughput of the entire system.

[0031] (C) a Second variant implementation

Figure 10 is a diagram illustrating a second variant implementation, in which executing a sequence of handover the source base station 11a of handover assesses whether the transmission of the packets (packet forwarding) or not, based on the type of communication services, and provides the mobile station 14 for information on performing forwarding (information transfer is performed).

It is assumed that the source base station 11a of handover stores the packets is performed in real-time traffic (NRT traffic) because of File Transfer Protocol (FTP (file transfer Protocol)or web connection and the packets are performed in real-time traffic (traffic RT) in connection VoIP and streaming in different buffers BF11 and BR12, respectively, with different sequence numbers, prisoedinennymi to them, and performs scheduling for the transmission of these packets, as shown in Figure 10. It is also assumed that one of the m-2-th - m-th packet, forming the NRT traffic, and n-2-th - the n-th packet, forming the RT traffic, are in a state of transmission, and others are now stored in the buffers BF1 and BF2 and not transferred to the mobile station 14. In the second embodiment, the movement data is based on the policy, in which the packet forwarding communication services NRT, and the packet forwarding communication services RT does not occur. This occurs for the following reasons. With regard to packet communication services, which must be processed in real time, such as VoIP calls, it is preferable to withdraw without forwarding to voice transmission and reception took place without delay. As for packages with low requirements for the transfer of real-time services with high QoS, they should preferably be sent to the target station to obtain high-quality data.

If performing handover mobile station 14 performs the RT data exchange, then executing a sequence of handover unit 24b management HO (see figure 3) the source base station 11a of handover decides, based on the above policy travel packages to fulfill forwarding n-2-th packet transmitted in this is now, also not redirected to the target base station 11b of handover n-1-th to n-th packets that are currently stored. Unit 24b management HO includes in the message instruction on HO information about the move PH0, indicating that call forwarding has not been made, to notify the mobile station 14. In this case, the format of the message has the same format as shown in Fig.6. Mobile station 14, which has received information PH0 about moves, performs an operation similar to the operation shown in Fig and Fig.9, as shown in the first embodiment, without performing the processing reorder.

On the other hand, if performing handover mobile station 14, provides NRT data exchange, then executing a sequence of handover unit 24b management HO source base station 11a of handover decides to divert m-2-th packet, which is transmitted at the present time, also is forwarded to the target base station 11b of handover m-1-th - m-th packets that are currently stored. Then in the message instruction on HO enter information PH0 on the implementation of handover for notification of the completion of forwarding that is sent to mobile station 14. In this case, the format of the message has the same format as figure 6. Mob is supplemented flax station 14, which received information PH0 about the move, performs an operation similar to the operation shown in Fig and Fig.9, and the reorder processing is performed in the same manner as shown in the first embodiment.

[0032] 11 is a block diagram of the sequence of operations illustrating operation of the source base station 11a of handover to perform the above series of operations, which are steps similar to the steps shown in the block diagram of the first variant implementation, shown in Fig.7, and denoted by the same reference position. The difference is the stage 255', which determines whether the movement of packets (packet forwarding) or not, depending on whether the service communication service communication NRT or service RT. If the service is a communications service, RT, unit 24b management HO decides to failure forwarding, enter information PH0 on the move (=“1”: the moves are not met) message-instruction on HO and sends it to the mobile station (step 256), and the unit 24a buffer management gives an instruction for deletion of packets remaining in the buffer 21 (step 257).

On the other hand, if at step 255' decided to move packages, unit 24b management HO puts it in the message instruction from siteline HO information PH0 on the move (=“0”: the move is made) and sends it to the mobile station 14 (step 258), and block 24a buffer management gives an instruction to forward the remaining in the buffer 21 of the packages (the packages move) to the target base station 11b of handover (step 259).

[0033] Alternative

In the second embodiment, the movement is not performed if the communication service is a communication service RT, but in some cases, packets can be forwarded or not forwarded, depending on the settings, even if the communication service is a communication service RT (e.g., VoIP calls). Such an alternative exists to support the case shown in Fig, which is a block diagram of the sequence of operations illustrating operation of an alternative source base station 11a of handover, in which the same stages of the processing sequence of the first variant implementation, shown at 11, denoted by the same reference position. The difference is the presence of step 265, if the communication service is a communication service RT, check that the unit is designed to divert or not, otherwise, block 24b management HO decides to failure forwarding, enter information PH0 in the message instruction on HO about the move (=“0”: the movement is not running) and sends it to the mobile one hundred is the information (step 256), and block 24a buffer management gives an instruction to remove remaining in the buffer 21 packet (step 257).

On the other hand, if at step 265 units are designed to forward packets, block 24b management HO enters information PH0 in the message instruction on HO about the move (=“0”: the move is performed) and sends it to the mobile station 14 (step 258), and the unit 24a buffer management gives an instruction to forward the remaining in the buffer 21 of the packages (the packages move) to the target base station 11b of handover (step 259).

[0034] Fig is a block diagram illustrating the processing of reorder mobile station alternative, in which the steps similar to the steps in the processing sequence for the first variant implementation, shown in Fig.9, denoted by the same reference positions, and the difference is that the time to continue processing reorder switches depending on whether the communication service call VoIP or not. In other words, it is checked whether the type of call, the VoIP call (step 312), if at the step 309 is not received RLC SDU, the numbers in the sequence which are continuous, and if there is a VoIP call, the control unit 34 monitors has expired if the specified first set time TS1 (step 310), repeats the processing of p is the following step 308, if time has not expired, or directs stored PDCP PDU to the upper level, if the fixed time has expired, even if the numbers in the sequence are not continuous (step 311). If at step 312 the type of call is a VoIP call, the control unit 34 monitors has expired if the second set time TS2 (<TS1) (step 313), repeats the processing after step 308, if the time has not expired, or directs stored PDCP PDU to the upper level, if the fixed time has expired, even if the numbers in the sequence are not continuous (step 311).

According to the above alternative, VoIP quality can be improved by forwarding packets even in the case of a VoIP call, and the time delays in the processing of reorderings can be reduced by reducing the set time TS2.

[0035] (D) a Third option exercise

A third option exercise is a variation of the implementation to determine whether the movement of packets (packet forwarding) depending on whether the source base station of handover the function of moving packages or not, by providing this information on the implementation of the mobile station. Fig is a block diagram illustrating a base station, in which the control unit buffer has a simplified configuration without function PE is Emesene packages and parts similar to the parts of the base station according to the first variant implementation, shown in Figure 3, denoted by the same reference position. The difference is that the block 24a' control buffer has a simplified configuration and has no forwarding of packets to the target base station 11b of handover or function planner travel packages.

Fig is a block diagram of the sequence of operations illustrating operation of the source base station of handover, in which the steps are similar to the steps shown in the block diagram of the sequence of operations according to the first variant implementation, shown in Fig.7, denoted by the same reference position. The difference is the determination at step 255, and you (packet forwarding) or not moving packages depending on whether the source base station 11a of handover forwarding and function planner travel packages. If these features are not installed, the unit 24b management HO decides to failure forwarding, enters the message instruction on HO information PH0 on the move (=“1”: the movement is not running) and sends it to the mobile station (step 256), and the unit 24a buffer management gives an instruction to remove remaining in the buffer 21 packet (step 257).

[0036] (E) a Fourth option exercise

In the above embodiments, the implementation level PDCP installed in aGW 12, which represents a host station, and the RLC level and the lower level is installed in the base station 11, as shown in Fig(A), but as shown in Fig(B), the system can be configured so that the levels of the PDCP, RLC and the lower level is installed in the base station 11, and only simple functions such as the routing function packages that can be installed in aGW 12. In the system configuration depicted in Fig(B), the function accession numbers sequence can be provided by the base station. Fig is a diagram illustrating the forwarding during execution of handover in such a system.

From the host station 12 in the source base station 11a handov the RA sends three packets, in the base station attached n-2-th, n-1-th and n-th batch numbers. It is assumed that handover starts in a state where these n-2-th, n-1-th and n-th packets remain in the buffer is not sent to the mobile station. If these n-2-th, n-1-th and n-th packets will be forwarded during the execution of a sequence of handover, these packages will be moved from the source base station 11a of handover in the target base station 11b of handover, as shown in Fig. During this forwarding to the target base station 11b of handover can be sent packets from the host station 12. In this case, the target base station 11b of handover will not be able to attach the correct number in the sequence received from the host station 12 packages. Therefore, while forwarding to the target base station 11b of handover n-2, n-1-th and n-th packets that were not sent to the mobile station, the source base station 11a of handover performs the forwarding of the sequence numbers in the target base station of handover. In other words, is forwarded n+1-th number in the sequence, intended for connection to a packet that is sent from the host station 12 to the target base station 11b of handover. Thus, the unit 24 controls the target base station 11b of handover can attach exactly n+1-th number in the sequential matching is Telenesti to the package, even if the packets are sent from the host station 12 to the target base station 11b of handover during forwarding.

In case the fourth version the implementation information PH0 about the move to indicate that call forwarding has been completed or not, may also be entered in the message instruction on HO and sent to the mobile station, whereby in case of default forwarding processing reorderings can be omitted.

[0037] Fig is a flow diagram illustrating the procedure of handover fourth variant implementation, which procedures similar to the procedures of handover shown in the diagram in Fig denoted by the same reference position. The difference is that a sequence number SN is moved from the source base station 11a of handover in the target base station 11b of handover to move packets (packet forwarding).

According to the fourth variant of the implementation of the forwarding sequence numbers occurs during handover, even if the numbers in the sequence are set for packets in the source base station of handover thus, in the target base station of handover to the packages can be attached to the correct number in the sequence, and if the redirection fails, what about the reorder processing in the mobile station can be omitted.

[0038] the Technical result of the invention

According to the present invention, if the implementation of management handover not redirected remaining in the source base station of handover packets to the target base station of handover (when the move fails), the mobile station does not need to perform reordering, even if the numbers in the sequence are not continuous; therefore, will not generate excessive waiting time, and the delay time data is minimized, and the throughput of the entire system can be improved.

In addition, according to the present invention, the mobile station does not need to perform reordering, even if you are not redirected, depending on the communication status (for an overload condition, the state of occupancy of the buffer, the state of the installed functions), and the type of communication services, therefore, will not generate excessive waiting time, and the delay time data is minimized, and the throughput of the entire system can be improved.

In addition, according to the present invention, the packet forwarding occurs during handover even in the case of a VoIP call, thus the quality of VoIP can be improved, and the time delay arising from the processing of a reorder mobile station can be reduced is by reducing the duration of treatment reorder.

In addition, according to the present invention, the forwarding sequence numbers occurs during handover, even if a sequence number attached to the packet in the source base station of handover thus, in the target base station of handover to the packages can be attached to the correct number in the sequence, and if not redirected, the reorder processing in the mobile station can be omitted.

1. The base station containing:
when functioning as a target base station:
a buffer which stores packets received from the host station, and stores the packets forwarded from the source base station of handover, when performing the sequence of handover;
a transmission unit that sends stored in the buffer packets, which are attached to the number indicating the sequence to the mobile station; and
when functioning as a source base station:
the control unit, which informs the mobile station information of the implementation of the forwarding, which depends on the type of transfer and the implementation of the forwarding is used for the mobile station to determine if the implementation sequence of handover to exercise according to the numbers in the sequence reordering of packets, when atih from the target base station of handover.

2. The base station containing:
when functioning as a target base station:
a buffer which stores packets received from the host station, and stores the packets forwarded from the source base station of handover, when performing the sequence of handover;
a transmission unit that sends stored in the buffer packets, which are attached to the number indicating the sequence to the mobile station; and
when functioning as a source base station:
the control unit, which informs the mobile station information indicating the configured forwarding packets, and this information is used by the mobile station to determine whether to implement according to the numbers in the sequence reordering of packets received at the target base station of handover, when performing the sequence of handover.

3. Mobile station, comprising:
block reorder, which performs the reordering of packets, which are attached to the number indicating the sequence, according to these numbers in sequence;
a buffer which stores packets received from the base station; and a control unit, which determines in the exercise of a sequence of handover, if the reordering of packets received from the target b the gas station handover, based on the information of the implementation of the forwarding, which depends on the type of transmission and which is accepted from the source base station of handover.

4. Mobile station, comprising:
block reorder, which performs the reordering of packets, which are attached to the number indicating the sequence, according to these numbers in sequence;
a buffer which stores packets received from the base station; and a control unit, which determines in the exercise of a sequence of handover, if the reordering of packets received from the target base station of handover, on the basis of information that is taken from the source base station of handover, and which indicates the configured forwarding packets.