KR101558101B1 - Sgw(serving gateway), control method thereof, and recording medium for recording program for executing the control method - Google Patents

Abstract

The present invention relates to a serving gateway (SGW), a method for controlling the same, and a recording medium for recording a program for performing the same method. The method for controlling a SGW included in a long term evolution (LTE) network includes the steps of: storing a local delay value (D-value) distinguished based on a kind of a service of a packet; receiving a D-value from a mobility management entity (MME); calculating a final D-value obtained by adding the D-value, received from the MME, to a local D-value in a kind of a service of a relevant downlink packet when the downlink packet is received by a terminal having a downlink bearer in a deactivated state; and transmitting a downlink data notification signal to the MME after time corresponding to the calculated final D-value passes.

Description

Technical Field [0001] The present invention relates to a SGW and a control method thereof, and a recording medium on which a program for executing the control method is recorded (SGW (Serving Gateway), CONTROL METHOD THEREOF, AND RECORDING MEDIUM FOR RECORDING PROGRAM FOR EXECUTING THE CONTROL METHOD)

The present invention relates to an SGW included in an LTE (Long Term Evolution) network, a control method thereof, and a recording medium on which a program for executing the control method is recorded. More particularly, An SGW for transmitting a DDN (Downlink Data Notification) signal to an MME (Mobility Management Entity) after a short period of time, a control method thereof, and a recording medium on which a program for executing the control method is recorded.

In the LTE (Long Term Evolution) network, the wireless resources of the UE are released when the transmission / reception traffic to the UE is not present for a predetermined time, the UE (User Equipment) to the eNodeB (corresponding to the base station) to the SGW (Serving Gateway)

This is to increase efficiency by allowing a plurality of terminals to share wireless resources in a time division manner. In this case, the UE enters an idle state.

When the UE enters the Idle state, the downlink bearer to the UE becomes inactive. Here, the bearer is a kind of data transmission channel.

When the traffic to the terminal entering the idle state is received from the network, the SGW waits for a time corresponding to the delay value (D-Value) received from the MME (Mobility Management Entity) To the MME.

Here, the DDN signal or the DDN message is a signal indicating that the downlink data has been generated. In response to the DDN signal, the MME transmits a signal for activating the downlink bearer to the terminal, that is, a Modify Bearer Request (MBR) .

The SGW activates the downlink bearer which has been inactivated according to the MBR signal received from the MME, and then transmits the downlink packet to the UE via the MME and the eNB.

However, in a case where a terminal in an idle state requests an Internet connection, for example, a DDN signal may be unnecessarily transmitted. An example of such a process is shown in FIG.

Referring to FIG. 1, the following will be described.

When the MME includes the D-V alue in the MBR or DDN ACK signal and transmits it to the SGW, the SGW temporarily stores the D-value received from the MME.

If there is no packet destined for the terminal or the terminal for a predetermined time and the terminal enters the idle state and there is an Internet access request of the terminal user, the processes from step S9 to step S19 are performed. These steps are not important for explaining the features of the present invention and will not be described in further detail.

At this time, if a downlink packet according to an Internet access request of the terminal is received from the outside, the SGW transmits a DDN signal to the MME after elapse of a time corresponding to the D-value stored in step S3, and the MME transmits a kind of response signal And transmits the DDN ACK signal to the SGW.

However, the MME can transmit the MBR signal to the SGW in response to the Initial Context Setup Response signal of step S19. In this case, the DDN signal transmitted from the SGW to the MME in step S23 corresponds to a signal unnecessarily transmitted.

That is, although the downlink bearer can be activated in the SGW by the MBR signal in step S27 even without the corresponding DDN signal, the SGW has unnecessarily transmitted the DDN signal to the MME because a predetermined downlink packet has occurred .

If the SGW waited for the MBR signal to be received from the MME after the downlink packet was received, it could not transmit the DDN signal to the MME.

For this purpose, the D-value value transmitted from the MME to the SGW may be set to a larger value. However, if the D-value becomes large, VoLTE may not be immediately received due to a delay due to a large D- Can be raised.

5.3.4 of 3GPP TS 23.401 (V10.4.0)

It is an object of the present invention to provide an SGW and a control method thereof for reducing the number of transmissions of a DDN signal unnecessarily transmitted from an SGW to an MME, And a recording medium on which a program for recording a program is recorded.

According to an aspect of the present invention, there is provided a control method of a SGW (Serving Gateway) included in an LTE (Long Term Evolution) network according to the present invention stores a local delay value (Local D-Value) ; Receiving a delay value (D-Value) from an MME (Mobility Management Entity); Calculating a final delay value by adding a local delay value corresponding to a service type of the downlink packet and a delay value received from the MME when a downlink packet is received on a terminal side in which the downlink bearer is inactive; And transmitting a DDN (Downlink Data Notification) signal to the MME after a time corresponding to the calculated final delay value has elapsed.

In order to achieve the above object, a control method of a SGW (Serving Gateway) included in an LTE (Long Term Evolution) network according to the present invention is a control method of a SGW 1 delay value (Local D-Value); Receiving a second delay value (D-Value) from an MME (Mobility Management Entity); A first delay value corresponding to a service type of a corresponding downlink packet received from the PGW and a second delay value received from the MME when a downlink packet is received from a terminal with the downlink bearer disabled, Calculating a delay value; And transmitting a DDN (Downlink Data Notification) signal to the MME after a time corresponding to the calculated final delay value has elapsed.

In order to achieve the above object, a SGW (Serving Gateway) included in an LTE (Long Term Evolution) network according to the present invention stores a local D-value distinguished according to a service type of a packet A storage unit; A delay value receiver for receiving a delay value (D-Value) from an MME (Mobility Management Entity); A calculation unit for calculating a final delay value obtained by adding a local delay value corresponding to a service type of the downlink packet and a delay value received from the MME; And a transmission unit for transmitting a DDN (Downlink Data Notification) signal to the MME after a time corresponding to a last delay value calculated by the calculation unit has elapsed, when a downlink packet is received on the terminal side where the downlink bearer is inactive .

According to another aspect of the present invention, there is provided a Serving Gateway (SGW) included in a Long Term Evolution (LTE) network according to the present invention, A delay value receiving unit receiving the 1st D-Value (1st D-Value) and receiving a second delay value (2nd D-Value) from the MME (Mobility Management Entity); A calculation unit for calculating a final delay value obtained by adding a first delay value corresponding to a service type of a downlink packet received from the PGW and a second delay value received from the MME; And a transmission unit for transmitting a DDN (Downlink Data Notification) signal to the MME after a time corresponding to a last delay value calculated by the calculation unit has elapsed, when a downlink packet is received on the terminal side where the downlink bearer is inactive .

As described above, according to the present invention, it is possible to minimize the transmission of unnecessary DDN signals by determining whether to transmit the DDN signal to the MME after different delay values are applied according to the service type of the downlink packet in the SGW.

1 is a signal flow diagram between respective devices of a conventional LTE communication network,
2 is a schematic configuration diagram of an entire communication system including an SGW according to an embodiment of the present invention,
Figure 3 is a functional block diagram of the SGW of Figure 1,
4 and 5 are flowcharts of control operations of the entire communication system including the SGW according to the first embodiment of the present invention,
6 is a control flowchart of the entire communication system including the SGW according to the first embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, embodiments of the present invention will be described in order to facilitate understanding of the present invention, and the present invention is not limited to these embodiments. In particular, the present invention can be configured by combining at least any one of individual components, individual functions, or individual steps included in each embodiment.

A schematic configuration of the entire LTE (Long Term Evolution) communication network including the Serving Gateway (SGW) 100 according to the first embodiment of the present invention is shown in FIG.

 The Evolved Universal Terrestrial Radio Access Network (E-UTRAN) 400, which is an LTE eNodeB, processes data traffic between a UE 300 and a CN (Core Network).

The mobile communication entity (MME) 500 handles signaling control between them. That is, the MME 500 takes charge of signal control between the eNodeB and the SGW 100, and determines where to route the incoming data from the terminal 300.

The SGW 100 is responsible for anchoring the UE between the eNodeB and the eNodeB and between the 3GPP network and the E-UTRAN 400. The packet data network GateWay (PGW) And is responsible for anchoring the terminal movement between the LTE and the non-3GPP network.

Each eNodeB included in the E-UTRAN 400 has a connection point with one or more MME 500 and SGW 100 to realize network redundancy and traffic load sharing.

The detailed description of the communication flow between the devices will be omitted, and the characteristic functions of the SGW 100 according to the first embodiment of the present invention will be described below with reference to FIG. 3, .

3, the SGW 100 according to the first embodiment of the present invention includes a storage unit 110, a delay value receiving unit 120, a calculating unit 130, and a transmitting unit 140 .

For example, the local delay value for the IMS packet is 0 ms and the local delay value for the NON-IMS packet is the local delay value. A value of 50 ms may be stored in the storage unit 110.

At this time, the classification of the service type of the packet can be distinguished by using the protocol and the port number included in each packet. For example, when the packet is a UDP (User Datagram Protocol) packet and the port number is 5060 or 5061, it may be an IMS packet. Therefore, it may be matched with the local delay value 0ms and stored in the storage unit 110, Assuming that the packet is an IMS packet, it may be matched with the local delay value of 50 ms and stored in the storage unit 110.

The delay value receiving unit 120 performs a function of receiving a delay value (D-Value) from an MME (Mobility Management Entity) At this time, the delay value receiving unit 120 may store the delay value received from the MME 500 in the storage unit 110.

For example, the delay value received from the MME 500 may be 50 ms.

The calculating unit 130 calculates a final delay value obtained by adding the local delay value corresponding to the service type of the downlink packet and the delay value received from the MME 500 previously.

Here, when a downlink packet is received on the side of the terminal 300 in which the downlink bearer is inactive, the calculation unit 130 calculates a local delay value corresponding to the service type of the downlink packet and a delay value received from the MME 500 And a final delay value obtained by adding a value of the final delay value.

That is, the calculating unit 130 may calculate a final delay value of 50 ms in total by adding the delay value 50 ms received from the MME 500 and the local delay value 0 ms for the IMS packet to the IMS packet, and the NON-IMS packet The final delay value of 100 ms can be calculated by adding the delay value 50 ms received from the MME 500 and the local delay value 50 ms for the NON-IMS packet.

The transmission unit 140 transmits a DDN (Downlink Data Notification) signal to the MME 500 after a time corresponding to the last delay value calculated by the calculation unit 130 has elapsed.

In particular, when the downlink packet is received on the side of the terminal 300 in which the downlink bearer is in an inactive state, the transmission unit 140 can transmit the DDN signal to the MME 500 after a time corresponding to the above- have.

Hereinafter, a signal and a control flow in the overall communication system including the SGW 100 according to an embodiment of the present invention will be described with reference to FIG.

First, in the SGW 100, a local delay value (Local D-Value) is set and stored. In this embodiment, the local delay value for the IMS packet is set and stored as 0 ms, and the local delay value Is assumed to be set and stored at 50 ms.

The MME 500 transmits a Modify Bearer Request (MBR) signal or a DDN ACK signal including the D-Value to the SGW 100.

The SGW 100 stores the final delay value obtained by adding the D-Value received from the MME 500, that is, the local D-value previously stored in the MME 500 D-Value.

The process of calculating the final delay value by the SGW 100 may be performed at the time of receiving the D-Value from the MME 500 or at the time of receiving the downlink packet from the PGW 200. [

Meanwhile, when the communication terminal UE 300 detects an Internet connection request from the user in the idle state, it transmits and receives signals for Internet connection. For example, it transmits a Service ReqUE 300 st signal to the eNB 400 .

The eNB 400 transmits a Service Request message 300 to the MME 500 and the communication terminal 300 and the eNB 400 receive the initial context setup request message 300 from the MME 500, An inter-radio activation is established and the preparation for transmitting an uplink packet is completed.

At this time, the uplink bearer for the corresponding terminal 300 may be activated in the SGW 100. For example, an uplink bearer for transmitting an uplink packet of the corresponding terminal 300 may be generated across the SGW 100, the MME 500, and the eNB 400.

Thereafter, when the communication terminal 300 transmits the uplink packet, the uplink packet is transmitted to the external communication network (for example, the Internet) via the eNB 400, the MME 500, the SGW 100, and the PGW 200 .

The eNB 400 transmits a response signal corresponding to the Initial Context Setup Request 300 of the MME 500 to the MME 500. The MME 500 transmits the Initial Context Setup Response signal to the SGW 100 (MBR) (Modify Bearer Request (300) st) signal.

After the MBR signal is received from the MME 500, the SGW 100 activates the downlink bearer. That is, at this point, a downlink bearer for the communication terminal 300 may be formed over the eNB 400, the MME 500, and the SGW 100, The downlink packet for the communication terminal 300 can be transmitted to the communication terminal 300 via the formed downlink bearer.

Here, the SGW 100 may transmit a response signal to the MME 500 for a Modify Bearer Request (300) st signal, that is, a Modify Bearer Response signal.

Meanwhile, when a downlink packet to the communication terminal 300 is received, the SGW 100 may transmit a DDN signal notifying the MME 500 of the reception of the downlink packet. If the received packet is a non-IMS packet Since the last delay value corresponds to a value obtained by adding 50ms as a local delay value to the MME 500 D-Value as described above, the SGW 100 transmits the DDN signal to the MME 500 only after the last delay value has elapsed. (500).

4, when the MBR signal is received from the MME 500 at the time when the final delay value has elapsed (step S65), the SGW 100 does not transmit the DDN signal to the MME 500 . This is because the downlink bearer for the communication terminal 300 has already been activated.

Therefore, the DDN signal transmitted from the SGW 100 to the MME 500 can be minimized. In other words, overload due to transmission and reception of frequent DDN signals causes various problems. According to the present invention, the transmission overhead of the DDN signal is differentiated for each packet by the traffic overload, thereby minimizing the transmission of the DDN signal.

This situation is effective when the downlink packet of step S63 described above is a response packet to the uplink packet of step S59.

For example, when the communication terminal 300 transmits a DNS query (that is, a query for converting a domain name to an IP address) for connection to the Internet (uplink packet), the DNS (Domain Name Server) (Downlink packet) in response to such a DNS, the response of which takes place in a relatively short period of time.

However, since the MBR signal is expected to be received from the MME 500 anyway in the SGW 100 according to the DNS query request of the communication terminal 300, the SGW 100 requests the SGW 100 to send a response (downlink packet) The MME 500 waits only for the D-Value time and waits for the local delay time for the non-IMS packet, rather than sending the DDN signal to the MME 500. In this case, The SGW 100 does not need to transmit the DDN signal to the MME 500 unnecessarily.

FIG. 5 shows a case where an IMS packet is received from an external communication network, unlike FIG.

Since steps S81 to S87 are the same as those in Fig. 4, duplicate description will be omitted.

When the IMS packet is received from the external communication network via the PGW 200, since the SGW 100 has a local delay value of 0 ms for the IMS packet, the DMB And transmits the signal to the MME 500.

The process from the step S95 of transmitting the DDN ACK to the SGW 100 by the MME 500 to the step S111 of transmitting the MBR signal to the SGW 100 corresponds to an example of the known technology, It is omitted. However, this process is a process of exchanging signals for preparation of incoming connection.

When the SGW 100 receives the MBR signal from the MME 500, it activates the downlink bearer and transmits a Modify Bearer Response signal to the MME 500.

Then, the SGW 100 transmits the previously received IMS packet through the activated downlink bearer so that the communication terminal 300 can receive the IMS packet.

In summary, FIG. 5 shows a case where an IMS downlink packet is received unlike FIG. When the IMS downlink packet is received, the local delay value for the IMS packet is 0 ms. Therefore, the SGW 100 waits for the D-value time of the MME 500 to elapse, The DDE signal is transmitted from the SGW 100 to the MME 500 immediately after the delay value (MME 500 D-Value) specified by the MME 500 elapses in the case of a voice call such as VoLTE. , Which means that the delay time can be minimized for the packets associated with the call.

Meanwhile, the SGW 100 'according to the second embodiment of the present invention has the same configuration as that of FIG. 3, but shows slight differences in its specific functions.

That is, the SGW 100 'according to the second embodiment of the present invention includes a storage unit 110', a delay value receiving unit 120 ', a calculating unit 130', and a transmitting unit 140 ' .

The storage unit 110 'may store applications or data for operating the SGW 100', or data received from outside or generated during operation of the SGW 100 '.

The delay value receiving unit 120 'receives a first delay value (1st D-Value) distinguished according to the service type of the packet from the PGW (PDN Gateway) 200' And a second delay value (2nd D-Value).

That is, the delay value according to the packet service type, that is, the PGW 200 'D-Value is set in the PGW 200', so that the corresponding PGW 200 'D-VALUE ) To the SGW 100 ', and the MME 500 transmits a fixed delay value irrespective of the packet type, that is, the MME 500 D-Value (corresponding to the second delay value) to the SGW 100' The SGW 100 'performs a function of receiving a first delay value from the MME 500 and a second delay value from the PGW 200', respectively.

The SGW 100 'may store the received first delay value or the second delay value in the storage unit 110'.

The calculation unit 130 'compares the first delay value corresponding to the service type of the corresponding downlink packet received from the PGW 200' and the second delay value received from the MME 500 to the delay value receiving unit 120 ' And performs a function of calculating the added final delay value.

For example, 0 ms may be received as a first delay value for an IMS packet from the PGW 200 ', and 50 ms as a first delay value for a non-IMS packet, wherein the calculating section 130' (0 ms or 50 ms) corresponding to the downlink packet to the second delay value received from the MME 500.

The transmission unit 140 'transmits a DDN (Downlink Data Notification) signal to the MME 500 after a time corresponding to the final delay value calculated by the calculation unit 130' has elapsed.

In particular, when the downlink packet is received on the side of the terminal 300 in which the downlink bearer is inactive, the transmitting unit 140 'transmits the DDN signal to the MME 500 after a time corresponding to the above-described final delay value has elapsed .

Hereinafter, signals and control flows between some communication system devices including the SGW 100 'according to the second embodiment of the present invention will be described with reference to FIG.

In FIG. 6, the communication terminal 300 and the eNB 400 shown in FIGS. 4 and 5 are omitted for convenience.

First, a delay value according to the type of the downlink packet, that is, the PGW 200 'D-Value is set and stored in the PGW 200'.

In this embodiment, it is assumed that 0 ms is set for the IMS packet and 50 ms is set for the non-IMS packet in the PGW 200 '.

The SGW 100 'stores the received D-Value of the MME 500 when a delay value irrelevant to the service type of the packet is received from the MME 500, that is, the MME 500 D-Value.

When the downlink packet is received, the PGW 200 'can determine the service type of the downlink packet. For example, by using the protocol and the port number included in the packet, the PGW 200' can do.

The PGW 200 'transmits the downlink packet to the SGW 100', and at the same time transmits the PGW 200 'D-Value corresponding to the corresponding downlink packet to the SGW 100'. For example, the PGW 200 'may transmit D-values set by the PGW 200' using a private extension IE when transmitting a downlink packet.

For example, if the downlink packet is an IMS packet, the PGW 200 'transmits 0ms to the SGW 100' in the downlink packet. If the downlink packet is a non-IMS packet, the PGW 200 ' Transmits 50ms to the SGW 100 'by including it in the downlink packet.

The SGW 100 'calculates a final delay value by adding the previously stored D-Value of the MME 500 and the PGW 200' included in the corresponding downlink packet, and waits for a time corresponding to the final delay value And transmits the DDN signal to the MME 500.

For example, if the downlink packet is an IMS packet, the SGW 100 'transmits a DDN signal after waiting for a time corresponding to the D-Value of the MME 500. If the downlink packet is a non-IMS packet The SGW 100 'transmits the DDN signal after waiting for 50 ms more than the D-Value of the MME 500.

Needless to say, the process of performing each of the above-described embodiments can be performed by a program stored in a predetermined recording medium (for example, a computer readable medium).

The present invention is not limited to the above-described specific embodiments, and various modifications and changes may be made without departing from the gist of the present invention. It is to be understood that such variations and modifications are intended to be included in the scope of the appended claims.

100, 100 ': SGW 200, 200': PGW
300, 300: UE 400: E-UTRAN
500: MME 110, 110 '
120, 120 ': delay value receiving unit 130, 130': calculating unit
140, 140 '

Claims (7)

A control method of a Serving Gateway (SGW) included in an LTE (Long Term Evolution) network,
(a) receiving a first delay value (Local D-Value) differentiated according to a service type of a downlink packet from a PGN (PDN GATEWAY);
(b) receiving a second delay value (D-Value) from a Mobility Management Entity (MME);
(c) when a downlink packet is received on the terminal side in which the downlink bearer is inactive, a first delay value corresponding to a service type of a corresponding downlink packet received from the PGW and a second delay value received from the MME Calculating an added final delay value;
(d) transmitting a DDN (Downlink Data Notification) signal to the MME after a time corresponding to the last delay value calculated in the step (c) has elapsed. The method according to claim 1,
Wherein the first delay value received in step (a) is distinguished by a value corresponding to an IMS (IP Multimedia Subsystem) packet and a value corresponding to a NON-IMS packet. delete A computer-readable recording medium having recorded thereon a program for executing the method of claim 1 or 2. In a Serving Gateway (SGW) included in an LTE (Long Term Evolution) network,
Receives a first delay value (1st D-Value) differentiated according to the service type of the downlink packet from the PGW (PDN GATEWAY) and receives a second delay value (2nd D-Value) from the MME (Mobility Management Entity) A delay value receiver;
A calculation unit for calculating a final delay value obtained by adding a first delay value corresponding to a service type of a downlink packet received from the PGW and a second delay value received from the MME;
And a transmission unit for transmitting a DDN (Downlink Data Notification) signal to the MME after a time corresponding to a last delay value calculated by the calculation unit has elapsed, when a downlink packet is received on the terminal side where the downlink bearer is inactive . 6. The method of claim 5,
Wherein the first delay value received from the PGW is distinguished by a value corresponding to an IMS (IP Multimedia Subsystem) packet and a value corresponding to a NON-IMS packet. delete

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