WO2014163346A1

WO2014163346A1 - Scheme for congestion control in a mobile communication system

Info

Publication number: WO2014163346A1
Application number: PCT/KR2014/002716
Authority: WO
Inventors: Song-Yean Cho; Sang-Soo JEONG; Beom-Sik Bae
Original assignee: Samsung Electronics Co., Ltd.
Priority date: 2013-04-01
Filing date: 2014-03-31
Publication date: 2014-10-09
Also published as: KR20140119530A; KR102178540B1

Abstract

Disclosed is a method of performing a congestion control in a mobile communication system. The method includes: receiving, by a load manager, load information from an eNB; and transmitting a load notification message including the received load information to a PDN gateway (PGW) or a service gateway (SGW) so as to trigger the congestion control. By providing the method of performing the congestion control in the mobile communication system, it is possible to efficiently use a resource of an eNB and to prevent a traffic service required to secure a desired bit rate from being stopped.

Description

SCHEME FOR CONGESTION CONTROL IN A MOBILE COMMUNICATION SYSTEM

The present disclosure relates to a method and system of controlling congestion in a mobile communication network, and entities constituting the system, and more particularly to a scheme of controlling congestion of a user plane using load information of an evolved Node B (eNB).

FIG. 1 illustrates a configuration of a communication system in which User Equipment (UE) is connected to an external network through a mobile network.

The UE 180 is connected to an evolved Node B (eNB) 110, and supplied with a communication service. The mobile network may further include at least one of a mobile management entity (MME) 100, a serving gateway (SGW) 120, a packet data network gateway (PGW) 130, a policy and charging rule function (PCRF) 170 and a traffic detection function (TDF) 140, as well as the eNB 110. The external network to which the user equipment 180 is connected through the mobile network may include at least one application server 150.

In such a mobile communication network, a method of controlling a user plane can be achieved as follows:

First, in the case that a transmission rate of the user plane is controlled by distinguishing a service or an application, the control of the transmission rate or a gating can be established in such a manner that the PGW 130 or the TDF 140 detects the service/application and then a packet dropping is performed or a buffering is carried out for a long time, so as to delay a time spent for the transmission.

Second, in the case that a transmission rate of a user plane is controlled without distinction of a service or an application, the control of the transmission rate or the gating can be achieved in such a manner that when congestion occurs in the eNB 110, an Internet Protocol (IP) flow is randomly selected from IP flows of various services/applications using any one bearer with relation to a bearer in which a bit rate is not guaranteed, i.e., a non-guaranteed bit rate, and a packet of the selected IP flow is dropped or buffered for a long time, so as to delay a time spent for the transmission.

Since the first method of controlling the transmission rate performs a de-prioritization for a data traffic of a specific service/application without relation to the load status of the user plane, the de-prioritization for the specific data traffic is performed even in the state that the eNB has enough resources, resulting in an efficient use of the resources of the eNB.

The second method of controlling the transmission rate is a scheme of performing a de-prioritization for the IP flow which is randomly selected from the IP flows of a specific bearer in the eNB without considering a feature of the service/application or a traffic characteristic. For example, in the case of a video service which is not provided by a mobile network operator (MNO) such as Youtube, if a bit rate which is not satisfied though a scheme of controlling such a transmission rate is applied, only charge information is counted and a quality of experience (QoE) which a user feels may be rather deteriorated even though a data traffic is provided.

The present disclosure has been made to solve the above-mentioned problem in the conventional art, and an aspect of the present disclosure is to provide a scheme and system of controlling congestion of a user plane, and entities constituting the system, in which the congestion is controlled in consideration of a property of a service/application of a traffic being selected according to a load status of an eNB by using a minimal signaling and a minimal processing overload.

In accordance with an aspect of the present disclosure, a method of a load manager performing a congestion control using load information in a mobile communication system is provided. The method includes: receiving an identifier of a cell and the load information of the cell from an eNB; and transmitting a load notification message, which triggers the congestion control based on the received cell identifier and load information, to an entity coordinating a policy for traffic.

In accordance with another aspect of the present disclosure, an apparatus for performing a congestion control by using load information in a mobile communication system is provided. The apparatus includes: a transceiver configured to receive an identifier and load information of a cell from an eNB and transmits a load notification message to an entity coordinating a policy for traffic; and a controller configured to control to transmit the load notification message, which triggers the congestion control based on the received cell identifier and load information, to the entity coordinating the policy for the traffic.

In accordance with still another aspect of the present disclosure, a method of performing a congestion control in a mobile system is provided. The method includes: obtaining an identifier of a service of data by performing a deep packet inspection (DPI) with respect to the data transferred through an eNB to UE; marking the identifier of the service and a minimal bit rate of the data on a GPRS tunneling protocol-user (GTP-U) header of the data and transmitting the GTP-U header of the data; receiving a response message for the marked GTP-U header from the eNB; and performing the transmission rate control of the data according to an acceptance possibility value for the minimal bit rate read from the GTP-U header of the received response message.

In accordance with still another aspect of the present disclosure, an apparatus for performing a congestion control in a mobile communication system is provided. The apparatus is configured to obtain an identifier of a service of data by performing a DPI for the data transferred through an eNB to UE; mark the identifier of the service and a minimal bit rate of the data on a GTP-U header of the user data so as to transmit the GTP-U header of the data; receive a response message for the marked GTP-U header from the eNB; and perform a transmission rate control of the data according to an acceptance possibility value for the minimal bit rate which is read from the GTP-U of the received response message.

Since the congestion control is performed in consideration of use of resources of an eNB, it is possible to efficiently use the resources of the eNB. Further, since a characteristic of each service/application is considered in the congestion control, it is possible to prevent the traffic service, in which a guarantee of a desired bit rate is required, from being stopped due to an indiscriminating congestion control.

Furthermore, since a signaling and additional process for controlling the congestion in the system where irregular congestion occurs is not required, an efficient operation of the system is possible.

The above and other aspects, features, and advantages of the present disclosure will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a view illustrating a configuration of a communication system in which user equipment is connected to an external network through a mobile network;

FIG. 2 is a view illustrating a configuration of a mobile communication system according to an embodiment of the present disclosure;

FIG. 3 is a view illustrating a configuration of a system of controlling a transmission rate according to a first embodiment of the present disclosure;

FIG. 4 is a view illustrating an operation of controlling a transmission rate of the mobile communication system according to an embodiment of the present disclosure;

FIG. 5 is a view illustrating a configuration of a system of controlling a transmission rate according to a second embodiment of the present disclosure;

FIG. 6 is a view illustrating an operation of controlling a transmission rate of the mobile communication system according to an embodiment of the present disclosure;

FIG. 7 is a view illustrating a configuration of a system of controlling a transmission rate according to a third embodiment of the present disclosure;

FIG. 8 is a view illustrating an operation of controlling a transmission rate of the mobile communication system according to an embodiment of the present disclosure;

FIG. 9 is a view illustrating a path of data through which the user equipment in an active state is connected to the eNB, a serving gateway (SGW) and a packet data network gateway (PGW) according to an embodiment of the present disclosure;

FIG. 10 is a view illustrating a configuration of a mobile communication system according to another embodiment of the present disclosure;

FIG. 11 is a view illustrating an operation of controlling a transmission rate of a mobile communication system according to a fourth embodiment of the present disclosure;

FIG. 12 is a view illustrating a configuration of a header of a GPRS tunneling protocol-user (GTP-U) of a user traffic which a packet data network gateway (PGW) transmits to the eNB according to an embodiment of the present disclosure;

FIG. 13 is a view illustrating a configuration of a header of a GPRS tunneling protocol-user (GTP-U) of a user traffic which a packet data network gateway (PGW) transmits to the eNB according to an embodiment of the present disclosure;

FIG. 14 is a view illustrating a process of controlling congestion of the PGW according to a fourth embodiment of the present disclosure; and

FIG. 15 is a view illustrating a configuration of a load manager according to an embodiment of the present disclosure.

Hereinafter, preferred embodiments of the present disclosure will be described with reference to the accompanying drawings. A detailed description of known functions and configurations incorporated herein will be omitted as it may make the subject matter of the present disclosure rather unclear. Then, terms described later are defined in consideration of the functions of the present disclosure, but may vary according to the intention or convention of a user or operator. Therefore, the definition needs to be determined based on the overall contents of the present specifications.

In the detailed description of the present disclosure, an example of interpretable meanings of some terms used in the present disclosure is proposed. However, it is noted that the terms are not limited to the example of the interpretable meanings which are proposed below.

An eNB is a subject which communicates with user equipment, and may be referred to as a base station (BS), a node B (NB), an eNode B (eNB), an access point (AP), and the like.

The UE is a subject which communicates with the eNB, and may be referred to as an user equipment, a mobile station (MS), mobile equipment (ME), a device, and the like.

According to the first, second and third embodiments of the present disclosure, the mobile communication system performs a congestion control of a user plane through notification of load information and a selection of traffic by using a load manager.

FIG. 2 is a view illustrating a configuration of a mobile communication system according to an embodiment of the present disclosure.

The load manager 200 is an entity which is located within a mobile network, and functions as a trigger to perform a congestion control based on load information by collecting load information from at least one eNB 230 to transmit the collected load information to other entities, e.g., SGW, PGW, PCRF and TDF, in the communication system. Further, the load manager 200 may obtain information on UE to perform an operation of de-prioritization, i.e., a congestion control, through an interaction with a mobility management entity (MME) 220, and information on the PGW 210 or the SGW 250 from the MME 220. Selectively, the load manager 200 may transmit the load information and additional information, on an object for which the de-prioritization is performed, to the PCRF or any one of the PGW 210, the SGW 250 and the TDF 240 for which an operation of the de-prioritization is performed. Selectively, the load manager 200 may trigger a control of a transmission rate according to a load status which is dynamically changed.

The load manager may be referred to as various names such as a load manager function (LMF), a load manager entity (LME), a load information function (LIF), a load information entity (LIE), a congestion manage function (CMF), a congestion manage entity (CME), a congestion control function (CCF), a congestion control entity (CCE), and the like.

The load information which the load manager 200 collects from the eNB 230, and the like may be expressed as load status information, load level information, or load severity information, and for example may include percentage information on a currently used capacity of each radio channel of the eNB 230, or percentage information of a currently used capacity of each piece of quality control information (QCI) which is a discriminator of quality of service (QoS).

In the first, second, and third embodiments, the mobile communication system performs a control of a transmission rate by using the load manager 200.

FIG. 3 is a view illustrating a configuration of a system of controlling a transmission rate according to a first embodiment of the present disclosure.

The load manager 200 is connected to the eNB 230, and then receives the load information including identification (ID) of the eNB and a load level from the eNB 230. The load manager 200 inquires a configuration table stored therein and identifies a region related to the eNB 230, and then picks up at least one PGW 210 managing the eNB 230. The load manager 200 transmits load notification (or overload notification), which includes information on an eNB subjected to a load, e.g., E-UTRAN cell global identifier (EGGI) which is identification (ID) of a cell, or information on the UE ID and a load level, to the at least one selected PGW 210. Selectively, the load manager 200 may transmit the load notification to an entity, e.g., PCRF, which coordinates a policy for traffic. Further, the load notification may be transmitted through the PCRF to the PGW 210. The PGW 210 receiving the load notification performs the control of the transmission rate for the UE of the corresponding cell by using the eNB information or the UE information included in the load notification. At this time, the PGW 210 may acquire information on the UE in the cell of the eNB in communication with the MME 220. Selectively, the DPI and the operation of the transmission rate control which the PGW 210 performs may be also performed by the TDF 240. An operation according to the embodiment in FIG. 3 will be described in detail with reference to FIG. 4.

FIG. 4 is a view illustrating an operation of controlling a transmission rate of the mobile communication system according to the embodiment of the present disclosure.

The eNB 230 accesses an address as a result of a Domain Name Server (DNS) query in which the load manager 200 sets as a local information parameter, or an address designated through an operation and maintenance (O＆M), so as to set a connection with the load manager 200 in step 400.

The load manager 200 transmits setting information, which the eNB 230 requires to report the load information, to the eNB 230 in step 402.

The setting information may include reference information and information on an object to be reported, which are used for reporting an amount of currently used resources among available resources for non-GBR bearers. The reference information may be an interval in the case of a periodic report, and a threshold, e.g., 50%, 60%, 70%, 80%, or 90%, of the amount of the used resources in the case of an aperiodic report. The information on the object to be reported may be a capacity (%) of each radio channel which is currently used. For example, the load manager 200 may include and transmit the setting information, which includes information meaning ‘70%’, ‘used capacity (%)’, to the eNB 230 for the purpose of reporting a currently used capacity (%) when the amount of the used resource is higher than the threshold of 70%.

The eNB 230 monitors the resource in the eNB 230 based on the setting information, and notifies the load manager 200 of the load information in step 404.

In a case of having received notification that a capacity more than the threshold required to trigger the control of the transmission rate is used, the load manager 200 picks up at least one PGW 210 related to the eNB 230 by using the configuration table set in the load manager 200 in step 406.

Table 1 indicates an example of the configuration table stored in the load manager 200.

Table 1

ENB	Related PGW
eNB1, eNB2, eNB3	PGW1, PGW2
eNB4, eNB5, eNB6	PGW2, PGW3

The load manager 200 stores information on the PGW which manages a corresponding eNB using the identification (ID) of the eNB (eNB ID or ECGI) in the form illustrated in Table 1, and uses the PGW information in a selection of the PGW related to the eNB, i.e., responsible for the eNB, in step 406.

The load manager 200 notifies the picked-up PGW 210 of the load information in step 408. Selectively, the load manager 200 may notify the PGW information to an entity, e.g., PCRF, which coordinates a policy for traffic. Further, the load notification may be transmitted through the PCRF to the PGW 210. The load information may include information on an extent of load severity and an ECGI or the ID of the UE which is information on the eNB to which the load is applied or in which congestion occurs.

The PGW 210 seeks UEs which are present in the cell which the ECGI designates by using the ECGI, and then selects UEs, which transmit and receive a current IP flow, among the sought UEs. The PGW 210 selects the bearers, for which the de-prioritization is performed, in consideration of QoS class identifier (QCI) of the bearer and subscription information of the selected UEs (in the case that a level in an application of a transmission rate is different according to a grade such as gold, silver, and bronze).

The PGW 210 performs the DPI for the IP flow in the selected bearer, and as a result, selects the IP flows for a specific service/application. The PGW 210 performs a control of the transmission rate by delaying a packet drop or a buffer for the selected IP flow in step 412.

Before the notification of the load information in step 408, the load manager 200 or the PGW 210 may seek the UE, i.e., ID information of the UE which is present in the cell which the ECGI designates by using the ECGI information when the load manager 200 or the PGW 210 receives notification of a change of user location information from the MME 220. Selectively, the load manager 200 or the PGW 210 may register the notification of the change of the user location information in the MME 220 in step 414. The MME 220 receiving the registration may notify the load manager 200 or the PGW 210 of the changed information each time when the cell in which the UE is present is changed in step 416. The information which the MME 220 notifies of may be notified in an aggregated form (in order to reduce the load of the network). For example, information of the UEs moving from a certain cell to another cell may be transmitted in the aggregated form. Based on the change information received from the MME 220, the load manager 200 or the PGW 210 may obtain information on a current cell of the UE.

Selectively, the DPI and the operation of the transmission rate control which the PGW 210 performs may be also performed by the TDF 240. The PGW 210 may transmit the load notification, which includes the load information, e.g., load level information or load severity information, received from the load manager 200 and the information, e.g., packet filters, on the IP flows in the bearer selected in step 410, to the TDF 240. The TDF 240 receiving the load notification may perform a DPI for the IP flows included in the load notification, and performs a control of the transmission rate in consideration of the received load information in step 420.

FIG. 5 is a view illustrating a configuration of a system of controlling a transmission rate according to a second embodiment of the present disclosure.

The second embodiment is a scheme which disperses a procedure of picking up an object for which a signaling and a de-prioritization of the first embodiment to the MME 220 by acquiring necessary information through an interaction of the load manager 200 and the MME 220.

The load manager 200 is connected to the eNB 230, and then receives the load information including identification (ID) of the cell or the UE, which causes congestion in the eNB, and a list of a load level from the eNB 230. The ID of the UE may be system architecture evolution (SAE) temporary mobile subscriber identity (S-TMSI). The load manager 200 receiving the load information requests the MME 220 for bearer information while transmitting the ID of the cell or UE to the MME 220, and receives information on the ID of the UE or the bearer satisfying a predetermined condition as a response from the MME 220. The load manager 200 selects and transmits the bearer or the ID of the UE, for which the de-prioritization is necessary, to the PGW 210, based on the information received from the MME 220. Selectively, the load manager 200 may transmit the information on the ID of the UE or the bearer to an entity, e.g., PCRF, which coordinates a policy for traffic. Further, the information on the ID of the UE or the bearer may be transmitted through the PCRF to the PGW 210. The PGW 210 performs a DPI based on the received information and picks up an IP flow for which the control of the transmission rate is necessary, so as to perform the control of the transmission rate such as a delay through a packet drop or a buffer. Selectively, the DPI and the operation of the transmission rate control which the PGW 210 performs may be performed by the TDF 240.

An operation according to the embodiment in FIG. 5 will be described in detail with reference to FIG. 6.

FIG. 6 is a view illustrating an operation of controlling a transmission rate of the mobile communication system according to the embodiment of the present disclosure.

The eNB 230 accesses an address obtained as a result of a DNS query in which the load manager 200 is set as a local information parameter, or an address designated through the O＆M, so as to set a connection with the load manager 200 in step 600.

The load manager 200 transmits setting information which is necessary for the eNB 230 to report the load information, to the eNB 230 in step 602.

The setting information may include reference information and information on an object to be reported, which are used for reporting an amount of currently used resources among available resources for non-GBR bearers. The reported reference information may be an interval in the case of a periodic report, or a threshold, e.g., 50%, 60%, 70%, 80%, or 90%, of the amount of the used resources in the case of an aperiodic report. The information on the object to be reported may be a capacity (%) of each radio channel which is currently used. For example, the load manager 200 may include and transmit the setting information, which includes information meaning ‘70%’, ‘used capacity (%)’, to the eNB 230 for the purpose of reporting a currently used capacity (%) when the amount of the used resource is higher than a threshold of 70%.

The eNB 230 monitors the resource in the eNB 230 based on the setting information, and notifies the load information to the load manager 200 in step 604. At this time, the eNB 230 transmits a list of the IDs of the cells or the IDs of the UEs, which transmit and receive lots of data causing the congestion while being in a connected mode, and the load information together. An example of the ID of the UE includes an S-TMSI. The S-TMSI is constituted of “a MME code + a temporary ID of the UE allocated by MME”.

If it is determined that a load which the load information indicates is larger than a threshold required to control the congestion, the load manager 200 receiving the load information of the eNB 230 selects the MME 220 by using an MME code included in the received S-TMSI in order to obtain information on the ID of the UE or the information on the bearer for which the control of the transmission rate is performed, and transmits a request for the bearer information including the ID of the cell or the S-TMSI list as a parameter to the MME 220 in step 606. The request for the bearer information may further include a transaction ID.

At this time, the load manager 200 transmits condition information on the bearers requesting information together, in which an example of the condition information includes a predetermined QCI, and a bearer characteristic such as a specific allocation and retention priority (ARP).

The MME 220 receiving the request of the load manager 200 selects the ID of the UE or the bearer satisfying the requested condition information among the bearers of the UEs corresponding to the S-TMSI list in step 608.

The MME 220 transmits a list, which includes at least one of associated PGW information, the ID of the UE which the PGW 210 uses, e.g., International Mobile Subscriber Identity (IMSI), and a subscription level, e.g., gold, silver, bronze and the like, among subscription information on the UEs, as a response to the request in step 606 to the load manager 200 in step 610. The associated PGW information includes information of the selected bearer, and the information of the selected bearer may be transmitted in the form of a Tunnel Endpoint Identifier (TEID) or the bearer ID. At this time, the list included in the response may further include a corresponding S-TMSI. Further, if at least one PGW is connected to the bearer of the UE, the associated PGW information is transmitted in the form of a list. For example, information on the UEs which are located together in a certain cell and move together to another cell may be transmitted in the aggregated form.

The load manager 200 selects the bearers of the UE in which the de-prioritization is required based on the information received from the MME 220 in step 612, and transmits the information including the ID of the UE for the selected bearer, e.g., the ID used in the PGW 210, particularly IMSI, and the bearer ID to the PGW 210 by means of a load notification message in step 614. At this time, the load manager 200 transmits the load information received from the based station in step 604 together to the PGW 210. Selectively, the load manager 200 may transmit the load notification message including the ID of the UE to an entity, e.g., PCRF, which coordinates a policy for traffic. Further, the load notification message may be transmitted through the PCRF to the PGW 210.

The PGW 210 receiving the load notification message performs a DPI using list information of the received bearer ID, and picks up an IP flow, for which the control of the transmission rate is performed, based on information on the service/application obtained as the result of the DPI and the received IMSI. Then, the PGW 210 performs a delay through a packet drop or buffer, so as to control the transmission rate in step 616.

Selectively, the DPI and the operation of the transmission rate control which the PGW 210 performs may be performed by the TDF 240. The PGW 210 may transmit the load notification, which includes the load information, e.g., load level information or load severity information, received from the load manager 200 and the information, e.g., packet filters, on the IP flows in the bearer selected in step 612, to the TDF 240 in step 618. The TDF 240 receiving the load notification may perform a DPI for the IP flows included in the load notification, and perform a control of the transmission rate in consideration of the received load information in step 620.

FIG. 7 is a view illustrating a configuration of a system of controlling a transmission rate according to a third embodiment of the present disclosure.

The third embodiment is a scheme of reducing a signaling and procedure for an interaction with the MME of the second embodiment by using information present in the eNB for the congestion control.

The load manager 200 is connected to the eNB 230, and then receives information, e.g., S-TMSI, on UE which is in a connection mode and causes the congestion, the bearer information, e.g., address of SGW, TEIDs, and a load level, or ECGI from the eNB 230. The load manager 200 determines whether the congestion control is necessary, identifies the address of the SGW using the bearer information, and transmits a load notification message including the address of the SGW, the load level, and the TEIDs to the SGW 250. The SGW 250 transmits the bearer information, the bearer ID and the IMSI sought based on the bearer information, and the load level information received from the load manager 200 to the PGW 210. The PGW 250 performs a DPI by using the information received from the SGW 250, and picks up an IP flow for which the control of the transmission rate is required, so as to perform the control of the transmission rate such as a delay through a packet drip or a buffer. Selectively, the DPI and the operation of the transmission rate control which the PGW 210 performs may be performed by the TDF 240. An operation according to the embodiment in FIG. 7 will be described in detail with reference to FIG. 8.

FIG. 8 is a view illustrating an operation of controlling a transmission rate of the mobile communication system according to the embodiment of the present disclosure.

The eNB 230 accesses an address obtained as a result of a DNS query in which the load manager 200 is set as a local information parameter, or an address designated through the O＆M, so as to set a connection with the load manager 200 in step 800.

The load manager 200 transmits setting information which is necessary for the eNB 230 to report the load information, to the eNB 230 in step 802.

The eNB 230 monitors the resource in the eNB 230 based on the setting information, and notifies the load manager 200 of the load information in step 804. At this time, the eNB 230 transmits an S-TMSI (MME code + a temporary ID of the UE allocated by the MME) which is the ID of the UE which is currently in a connection mode and causes congestion by transmitting and receiving lots of data, and the information of the bearers, e.g., the address of the SGW and the TEIDs, together to the load manager 200. The TEID which is information on the bearers corresponds to the SGW which is in an active state and connects an S1-user plane.

FIG. 9 is a view illustrating a path of data through which the UE in an active state is connected to the eNB, a serving gateway (SGW) and a packet data network gateway (PGW) according to the embodiment of the present disclosure.

Referring to FIG. 9, the UE 290 in the active state has a data path connected to a radio bearer 900 between the UE 290 and the eNB 230, an S1-U bearer tunnel 910 between the eNB 230 and the SGW 250, and an S5-U bearer tunnel 920 between the SGW 250 and the PGW 210.

The address of the SGW and the TEID transmitted through step 804 is information corresponding to the S1-U bearer tunnel, which is an S1-U SGW tunnel ID information allocated by the SGW 250 and notified to the eNB 230, or an S1-U eNB tunnel ID allocated by the eNB and notified to the SGW in order to be connected with the SGW.

If it is determined that the load status indicated by the load information is larger than the threshold required to control the congestion, the load manager 200 receiving the load information of the eNB 230 transmits the load notification to the SGW 250 by using the SGW address which is bearer information of the UE which is an object subjected to a control of the transmission rate in step 806. The load notification 806 which the load manager 200 transmits may include the TEID information and the load information (load level) received in step 804.

The SGW 250 receiving the load notification from the load manager 200 seeks corresponding bearers based on the TEID information included in the load notification, and seeks an IMSI and bearer IDs related to the sought bearers in step 808. Then, the SGW 250 transmits the IMSI and the load notification, which includes the load information (load level) received from the load manager 200, to the PGW 210 in step 810. The load notification which the SGW 250 transmits to the PGW 210 in step 810 may include the IMSI and the bearer ID, or the TEIDs. The TEIDs included in the load notification in step 810 is information corresponding to the tunnel S5-U bearer tunnel, and may become an S5 SGW TEID or S5 PGW TEID.

The PGW 210 receiving the load notification in step 810 performs a DPI, picks-up IP flows for which a congestion control is performed, based on the received IMSI, a bearer ID list, TEID list information and information on the service/application according to the result of the performance of the DPI, and performs a delay through a packet drop or buffering, so as to control the transmission rate in 812.

Selectively, the DPI and the operation of the transmission rate control, which the PGW 210 performs, may be performed by the TDF 240. The PGW 210 may transmit the load notification, which includes the load information, e.g., load level information or load severity information, received from the load manager 200 and the information, e.g., packet filters, on the IP flows in the bearer received in step 810, to the TDF 240 in step 814. The TDF 240 receiving the load notification may perform a DPI for the IP flows included in the load notification, and perform a control of the transmission rate in consideration of the received load information in step 816.

The fourth embodiment of the present disclosure is a scheme in which the mobile communication system performs the control of the transmission rate using a set minimal bit transmission rate.

In the schemes according to the first, second and third embodiments using the load manager, the PGW or the TDF may be allowed to control the transmission rate in consideration of a load status of the eNB. When the congestion lasts for a predetermined time, it is very effective to carry out a congestion control by performing a signaling and corresponding processes by using the schemes of the first, second and third embodiments. On the other hand, when the congestion does not last for the predetermined time but occurs at an irregular interval, a signaling for the congestion control occurring periodically may act as an overhead of the system.

When congestion lasting for a short time occurs at an irregular interval, a scheme of controlling the transmission rate considering a service characteristic is provided. The present embodiment is an effective scheme when a transmission of entire data is useless unless data traffic such video traffic is not carried out at a desired bit rate.

The fourth embodiment of the present disclosure will be described with reference to FIGS. 10 and 11.

FIG. 10 is a view illustrating a configuration of a mobile communication system according to another embodiment of the present disclosure.

The UE 290 transmits and receives the data traffic through a mobile network from an application server 1000 of an external network. The PGW 210 performing the congestion control performs a DPI for the data traffic, marks a service/application identifier detected as the result of the performance of the DPI and a minimal bit rate for the service/application on a GTP-U header of the corresponding data traffic, and transmits the GTP-U header through the SGW 250 to the eNB 230. The eNB 230 marks a possibility or an impossibility of accepting the minimal bit rate, and a possible time on the GTP-U header, and sends the data traffic through the SGW 250 to the PGW 210. The PGW 210 accepts the minimal bit rate of the corresponding data traffic or performs the congestion control in a manner of dropping a packet of the corresponding data traffic, in consideration of whether the GTP-U header for the data traffic arrives from the based station, and whether the possibility of accepting the minimal bit transmission rate is marked on an arrived GTP-U header.

The fourth embodiment will be described in detail with reference to FIG. 11.

FIG. 11 is a view illustrating an operation of controlling a transmission rate of a mobile communication system according to the fourth embodiment of the present disclosure.

The PGW 210 (or TDF) performs a DPI for the data traffic provided to the UE 290, marks an identifier distinguishing a service/application detected as the result of the performance of the DPI and a minimal bit rate for the service on a header of the general packet radio service (GPRS) tunneling protocol-user (GTP-U) transferring the data traffic, and transmits the GTP-U header to the SGW 250 in step 1100. In the embodiment, a congestion control operation performed by the PGW 210 may be also carried out by the TDF 240, but only the congestion control performed by the PGW 210 will be described for the convenience of the description.

Referring to FIG. 12, the identifier distinguishing the service/application is marked on a service class indicator (SCI) and the minimal bit rate is marked on an additional extension field.

FIG. 12 is a view illustrating a configuration of a header of a GPRS tunneling protocol-user (GTP-U) of a user traffic which a packet data network gateway (PGW) transmits to the eNB according to the embodiment of the present disclosure.

The minimal bit rate may be marked on the additional extension field 1200, and the identifier distinguishing the service/application may be marked on the SCI field 1202.

The PGW 210 stores a source address of the set TEID and an internal IP header, a destination address, a source port, a destination port, protocol information and minimal bit rate information in a desired region, e.g., a separate configuration table, in order to identify a response received from the eNB 230. Then, a timer T waiting for the response starts to count.

The SGW 250 inserts the header extension field marked by the PGW 210 into the header of the GTP-U without conversion, and transmits the header of the GTP-U to the eNB 230 in step 1102.

The eNB 230 which receives the minimal bit rate marked on the GTP-U header determines whether accepting of the minimal bit rate required for the corresponding traffic is possible in step 1103. At this time, the eNB 230 determines whether the accepting of the minimal bit rate is possible with reference to a status of a current eNB resource, a status of a resource allocated to the UE, and a maximal bit rate allowed to the UE.

FIG. 13 is a view illustrating a configuration of a header of a GPRS tunneling protocol-user (GTP-U) of a user traffic which the eNB transmits to a packet data network gateway (PGW) according to the embodiment of the present disclosure.

As the result of the determination, the eNB 230 marks information on the possibility of the accepting of the minimal bit rate and a time for which the accepting of the minimal bit rate is possible on an acceptance possibility field 1302 and a time field 1306 of the GTP-U header extension field 1300, and transmits the GTP-U header to the SGW 250 in step 1104. At this time, in the case that there is no uplink data, a dummy flag is marked on a dummy field 1304 of the GTP-U header extension field 1300, so as to indicate an absence of the uplink data.

The eNB 230 processes the GTP-U header for the received data, and then transmits the processed data to the UE.

The SGW 250 receiving the data including the possibility of the accepting for the minimal bit rate which the eNB 230 sets duplicates information of the possibility of the accepting, the presence or absence of the dummy and the time field to the GTP-U header of the data, and transmits the GTP-U header to the PGW 210 in step 1106.

The PGW 210 receives the GTP-U header through a relay of the SGW 250 in step 1106. The PGW 210 compares information, e.g., an address, a port and a protocol, of the TEID and the IP packet stored therein with the IP packet information of the received GTP-U header in step 1108. At this time, the PGW 210 compares the information on the stored source address and port with information on a destination address and a port of the received packet, and compares the information on the stored destination address and port with the information on the source address and the port of the received packet.

If the result of the comparison is identical and the acceptance possibility field and the time field of the extension field of the received GTP-U header are marked, it is determined that the stored minimal bit rate is guaranteed for a time marked on the time field. Accordingly, the transmission rate is controlled for the marked time to make the minimal bit rate be a lower limit for the corresponding traffic.

On the other hand, although information identical to the information of the received TEID and the IP packet is sought from the stored information, a corresponding IP flow is processed and dropped by a close gating when unacceptance is marked on the information.

In the comparison of step 1108, if an response having information same as stored information is not received within a time T, during which the PGW 210 is set to wait for the response, the PGW 210 resets a timer up to N times and increases a counter, so as to set the minimal bit rate value in the GTP-U header. Then, the PGW 210 transmits the GTP-U to the eNB 230. If the identical response is not received from the eNB 230 during an attempt of the N times in step 1108, the corresponding IP flow is processed and dropped by the close gating.

On the other hand, in the case that the response having information same as stored information is received in step 1108 and the acceptance possibility and the time are received, if the time has lapsed and the IP flow of the corresponding service/application must be transmitted, the PGW 210 marks the minimal bit rate on the extension field of the GTP-U header and starts an operation of transmitting the GTP-U header to the eNB again.

FIG. 14 is a view illustrating a process of controlling congestion of the PGW according to the fourth embodiment of the present disclosure.

The PGW 210 marks information on the minimal bit rate as an extension field on the GTP-U header of the traffic to be transmitted to the UE 290, and transmits the GTP-U header to the SGW 250. At this time, the PGW 210 stores the TEID information of the traffic and the IP packet information, e.g., an address, a port, and a protocol, therein. The PGW 210 starts to count a time in order to receive a response for the GTP-U header in step 1400.

The PGW 210 receives the GTP-U header through the SGW 250 from the eNB 230 in step 1402.

The PGW 210 compares the IP packet information and the TEID information marked on the received GTP-U header with the IP packet information and the TEID stored in step 1400, and determines whether the IP packet information and the TEID information of the GTP-U headed is identical to the stored IP packet information and TEID information in step 1404.

As the result of the determination, if the IP packet information and the TEID information of the GTP-U header are identical to the stored IP packet information and TEID information, the PGW 210 performs the control of the transmission rate for the traffic by using the acceptance possibility field of the minimal bit rate and the time field recorded in the extension field of the received GTP-U header in step 1406.

FIG. 15 is a view illustrating a configuration of a load manager according to the embodiment of the present disclosure.

The load manager 1500 may include a transceiver 1510 for transmitting and receiving a signal to/from other entities present in a network and a controller 1520 for controlling an operation of the congestion control according to the embodiments of the present disclosure.

The transceiver 1510 performs an operation of transmitting and receiving various signals to/from various entities, e.g., an eNB, an MME, a PGW, a SGW, a PCRF and a TDF, of the mobile communication system, and supports to use the signals in the operation of the congestion control of the controller 1520. For example, the transceiver 1510 may receive the cell ID and the load information from the eNB, and also may transmit the cell ID to the MME so as to receive the ID of the UE corresponding to the cell ID. Further, the transceiver 1510 may trigger the operation of the congestion control by transmitting a load notification message to the PCRF or the PGW.

The controller 1520 may control the load manager 1500 in order to perform various embodiments for the congestion control scheme of the above mentioned load manager. Accordingly, in the present disclosure, all the operations of the load manager should be interpreted as the operation of the controller 1520, except that the operations of the load manager are clearly interpreted as the operation of the transceiver 1510.

It is noted that the view of the configuration of the system, the view of the scheme of the congestion control, the view of the GTP-U header, and the view of the configuration of the load manager, which are illustrated in FIGS. 2 to 15, do not limit the scope of the present disclosure. That is, all configurations or steps of the operations illustrated in FIGS. 2 to 15 should not be interpreted as essentially structural elements for carrying out the present disclosure, and variations and modifications of the present disclosure may be implemented without departing from the scope of the present disclosure.

The above described operations may be implemented by providing a memory device storing a corresponding program code to the entity of the communication system, the function, the eNB, the load manager, or a specific structural element of the UE. That is, the entity, the function, the load manager, or the controller of the UE carries out the above described operations by reading and executing the program code stored in the memory device by means of a processor or a CPU.

The entity, the function, the eNB, the load manager, various structural elements of the UE, modules and the like may be operated by using a hardware circuit, e.g, a complementary metal oxide semiconductor based logic circuit, firmware, software, and/or a combination of hardware and the firmware and/or software embedded in a machine readable medium. As an example, various electric configurations and methods may be carried out by using electric circuits such as transistors, logic gates, and an application specific integrated circuit (ASIC).

Although the embodiment has been described in the detailed description of the present disclosure, the present disclosure may be modified in various forms without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be defined as being limited to the embodiments, but should be defined by the appended claims and equivalents thereof.

Claims

A method of a load manager performing a congestion control using load information in a mobile communication system, the method comprising:receiving an identifier of a cell and the load information of the cell from an eNB; andtransmitting a load notification message, which triggers the congestion control based on the received cell identifier and load information, to an entity coordinating a policy for traffic.
The method as claimed in claim 1, wherein the load notification message is transmitted through the entity coordinating the policy for the traffic to a PDN gateway (PGW), a serving gateway (SGW), or a traffic detection function (TDF).
The method as claimed in claim 1, before transmitting the load notification message, further comprising:transmitting the identifier of the cell to a mobile management entity (MME); andreceiving a response including an identifier of UE corresponding to the identifier of the cell from the MME,wherein the load notification message includes the identifier of the UE.
The method as claimed in claim 3, wherein the response received from the MME includes identifiers of a plurality of UEs corresponding to the identifier of the cell in an aggregated form.
The method as claimed in claim 3, wherein the response including the identifier of the UE further comprises bearer information corresponding to the identifier of the UE.
The method as claimed in claim 2, wherein in the receiving of the identifier and the load information of the cell, the load manager further receives an address of the SGW and information on a bearer tunnel between the eNB and the SGW.
The method as claimed in claim 2, wherein a transmission rate control or gating for traffic of the eNB is performed by at least one of the PGW, the SGW and the TDF, based on the load notification message.
An apparatus for performing a congestion control by using load information in a mobile communication system, the apparatus comprising:a transceiver configured to receive an identifier and load information of a cell from an eNB and transmits a load notification message to an entity coordinating a policy for traffic; anda controller configured to control to transmit the load notification message, which triggers the congestion control based on the received cell identifier and load information, to the entity coordinating the policy for the traffic.
The apparatus as claimed in claim 8, wherein the load notification message is transmitted through the entity coordinating the policy for the traffic to a PDN gateway (PGW), a serving gateway (SGW), or a traffic detection function (TDF).
The apparatus as claimed in claim 8, wherein the controller transmits the identifier of the cell to the MME and receives an identifier of UE corresponding to the identifier of the cell from the MME before the load notification message is transmitted, and transmits the load notification message including the identifier of the UE.
The apparatus as claimed in claim 10, wherein the response received from the MME includes identifiers of a plurality of UEs corresponding to the identifier of the cell in an aggregated form.
The apparatus as claimed in claim 10, wherein the response including the identifier of the UE further comprises bearer information corresponding to the identifier of the UE.
The apparatus as claimed in claim 9, wherein the controller further receives information on an address of the SGW and a bearer tunnel between the eNB and the SGW.
The apparatus as claimed in claim 9, wherein a transmission rate control or gating for traffic of the eNB is performed by at least one of the PGW, the SGW and the TDF, based on the load notification message.
A method of performing a congestion control in a mobile system, the method comprising:obtaining an identifier of a service of data by performing a deep packet inspection (DPI) with respect to the data transferred through an eNB to UE;marking the identifier of the service and a minimal bit rate of the data on a GPRS tunneling protocol-user (GTP-U) header of the data and transmitting the GTP-U header of the data;receiving a response message for the marked GTP-U header from the eNB; andperforming the transmission rate control of the data according to an acceptance possibility value for the minimal bit rate read from the GTP-U header of the received response message.
The method as claimed in claim 15, wherein in the performing of the transmission rate control, the transmission rate control of the data is performed according to the acceptance possibility value and an acceptance time value of the minimal bit rate which are read from the GTP-U header of the received response message.
The method as claimed in claim 15, further comprising:storing a tunnel endpoint ID (TEID) of the data and IP packet information before the receiving of the response message for the marked GTP-U header; andcomparing the stored TEID and IP packet information with the TEID and IP packet information of the received response message, so that it is determined whether they are identical, after the receiving of the response message for the marked GTP-U header.
The method as claimed in claim 15, wherein the congestion control is performed by one of a PGW, an SGW and a TDF.
An apparatus for performing a congestion control in a mobile communication system, the apparatus is configured to: obtain an identifier of a service of data by performing a DPI for the data transferred through an eNB to UE; mark the identifier of the service and a minimal bit rate of the data on a GTP-U header of the user data so as to transmit the GTP-U header of the data; receive a response message for the marked GTP-U header from the eNB; and perform a transmission rate control of the data according to an acceptance possibility value for the minimal bit rate which is read from the GTP-U of the received response message.
The apparatus as claimed in claim 19, wherein the transmission rate control of the data is performed according to the acceptance possibility value and an acceptance time value of the minimal bit rate which are read from the GTP-U header of the received response message.
The apparatus as claimed in claim 19, wherein a TEID of the data and IP packet information is stored before the response message is received, and the stored TEID and IP packet information are compared with the TEID and IP packet information of the received response message, so that it is determined whether they are identical, after the response message is received.
The apparatus as claimed in claim 19, wherein the mobile communication system is one of a PGW, an SGW and a TDF.