KR102371217B1 - Apparatus and method for controlling tcp connections in a wireless communication system - Google Patents

Abstract

Embodiments of the present invention provide an apparatus and method for controlling TCP connection termination for improving battery life of a client device such as a smart phone terminal in a wireless communication system. According to an embodiment of the present invention, a method of operating a client in a wireless communication system includes determining a data transmission deactivation time for at least one TCP connection among a plurality of transmission control protocol (TCP) connections, and deactivating the data transmission. terminating the TCP connection in time.

Description

Transmission control protocol connection control device and method of wireless communication system {APPARATUS AND METHOD FOR CONTROLLING TCP CONNECTIONS IN A WIRELESS COMMUNICATION SYSTEM

FIELD OF THE INVENTION The present invention relates generally to computing devices. The present invention more particularly relates to an apparatus and method for controlling a TCP connection in a wireless communication system.

Recently, in a wireless communication environment using an electronic device (or a client device) such as a smart phone, several network applications (eg, Facebook, Twitter, Email, Flipboard, AccuWeather) by interaction with independent and remote servers ) is executed. Most of these applications interact with servers through the establishment of short-lived transport protocol connections, for example, transmission control protocol (TCP) connections.

On the other hand, if the client device does not properly perform termination processing for TCP connections, a large amount of power may be consumed in the client device. To this end, there are typical methods of initiating termination processing for TCP connections at the client or at the server.

The existing client-initiated close in TCP connections processing is a method of immediately closing the inactive TCP connection when data exchange is complete. However, since this method terminates an inactive TCP connection that needs to be reused, the inconvenience of re-establishing the transport layer for reuse and time required for performing the procedure are required.

On the other hand, the processing of server-initiated close in TCP connections is processed after a server timeout with an interval of several seconds to several minutes (eg 30s, 60s, 120s), after which the server Initiates TCP connection termination by sending FIN (Finish) packets to

The short-lived connections are characterized by a limited frequency of data transfer between the client and server endpoints. Once data is exchanged, the remaining time of established TCP connections is idle. An established, still-idle TCP connection is vulnerable to a server timeout that causes a shutdown message (eg FIN (Finish) packets) at intervals ranging from a few seconds to a few minutes.

However, the server-initiated termination messages, along with the tail energy caused by the wireless communication network (eg 3G/LTE network), reduce the energy overhead caused by the network wireless state transition from the idle state to the active state. cause These delayed termination messages keep the air interface active for a longer time by resetting the radio-layer timer, and even cause energy overhead to trigger additional radio state transitions by turning the air interface on.

Accordingly, various embodiments of the present invention are to provide an apparatus and method for controlling a TCP connection in a wireless communication system.

Various embodiments of the present invention provide an apparatus and method for controlling a TCP connection for improving battery life of an electronic device such as a smart phone terminal in a wireless communication system.

Various embodiments of the present invention provide an apparatus and method for controlling a TCP connection for reducing energy overhead caused by a transition of a client such as a smart phone terminal from an idle state to an active state.

Various embodiments of the present invention provide an apparatus and method for initiating termination of TCP connections at a client.

Various embodiments of the present invention provide an apparatus and method for processing termination of TCP connections in a client proactively, bundled processing, or a combination thereof.

According to an embodiment of the present invention, a method of operating a client in a wireless communication system is provided. The method includes determining a data transmission deactivation time for at least one TCP connection among a plurality of transmission control protocol (TCP) connections, and terminating the TCP connection at the data transmission deactivation time.

According to another embodiment of the present invention, a method of operating a client in a wireless communication system is provided. The method includes a process of identifying at least one first TCP connection for which termination processing is initiated by a server from among a plurality of transmission control protocol (TCP) connections, and at least one of the TCP connections excluding the first TCP connection. It includes the process of bundling and terminating the first TCP connection together with the processing of the second TCP connection.

According to another embodiment of the present invention, a client device of a wireless communication system is provided. The apparatus includes a controller for determining a data transmission deactivation time for at least one TCP connection among a plurality of transmission control protocol (TCP) connections, and terminating the TCP connection at the data transmission deactivation time.

According to another embodiment of the present invention, a client device of a wireless communication system is provided. The device identifies at least one first TCP connection for which termination processing is initiated by the server from among a plurality of transmission control protocol (TCP) connections, and at least one second TCP connection other than the first TCP connection among the TCP connections and a controller for tying up and terminating the first TCP connection together with processing for the TCP connection.

Various embodiments of the present invention achieve a higher battery life by having a longer idle time without deteriorating the user experience or affecting application functions without the need to change application software in a client device such as a smartphone terminal. helps to

Other objects, functions and advantages will be apparent to those skilled in the art from the accompanying drawings and the following description of the preferred embodiment.
1 shows a network environment to which embodiments of the present invention are applied.
Figure 2 shows the operation of termination for a TCP connection at the client initiated by the server.
3A illustrates the operation of proactive TCP connection termination according to an embodiment of the present invention.
3B illustrates the operation of delayed TCP connection bundle termination according to an embodiment of the present invention.
4 illustrates a block configuration of a client device according to various embodiments of the present invention.
5 shows an overall software architecture for LPTCP according to various embodiments of the present invention.
6A illustrates a method for detecting a TCP connection termination time initiated by a server according to an embodiment of the present invention.
6B illustrates a method for detecting a guard timeout according to another embodiment of the present invention.
7 illustrates TCP connection termination operations according to various embodiments of the present invention.
8 is a diagram for explaining a combined operation of TCP connection precedence and bundle termination according to an embodiment of the present invention.
9A illustrates steps performed for a proactive TCP connection termination operation according to an embodiment of the present invention.
9B illustrates steps performed for a proactive TCP connection termination operation according to another embodiment of the present invention.
10A and 10B illustrate steps performed in a bundle termination operation for delayed TCP connections according to an embodiment of the present invention.
11 illustrates an overall flow of a TCP control method according to various embodiments of the present invention.
12 illustrates an operational flow of TCP control for estimating data transmission inactivity time or guard timeout according to an embodiment of the present invention.
13 illustrates an operational flow of TCP control for a method for proactively terminating an inactive, non-persistent TCP connection according to an embodiment of the present invention.
14 illustrates an operational flow of TCP control for a bundle termination method for an inactive, non-persistent TCP connection according to an embodiment of the present invention.
15 illustrates an operational flow of TCP control for combined methods including proactive and bundled termination for inactive, non-persistent TCP connections, according to an embodiment of the present invention.
16A and 16B show test results in terms of power saving for a TCP control operation according to various embodiments of the present invention.
17 illustrates test results in terms of network signaling reduction for a TCP control operation according to various embodiments of the present disclosure.
Although certain functions of the present invention are shown in some drawings and not in others, this is done for convenience only, as each function may be combined with any or all of the other functions according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, it should be noted that only the parts necessary for understanding the operation according to the embodiments of the present invention will be described below, and descriptions of other parts will be omitted so as not to obscure the gist of the present invention. In addition, the terms to be described later are terms defined in consideration of functions in the embodiments of the present invention, which may vary according to intentions or customs of users and operators. Therefore, the definition should be made based on the content throughout this specification.

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Accordingly, FIGS. 1 to 17 used to explain the principles of the present invention in this patent specification are for illustrative purposes only, and should not be construed as limiting the scope of the present invention.

Various embodiments of the present invention to be described below provide an apparatus and method for controlling TCP connections in an electronic device (or client) such as a smart phone terminal in order to improve battery life. Embodiments of the present invention may be applied to a computing device, for example, a network environment as shown in FIG. 1 .

Referring to FIG. 1 , a client 100 is connected to a server 200 through a network 300 . The network 300 may be a wireless communication system of 3G or long term evolution (LTE). The client 100 interworks with the server 200 through the execution of a plurality of applications (eg, App-A 11, App-B 12, App-C 13) 10, and as a result, can exchange various contents with the server 200. The client 100 and the server 200 may be connected to each other through a transmission protocol such as a transmission control protocol (TCP). The client 100 may be various electronic devices or user terminals, such as a smartphone.

Embodiments of the present invention help achieve higher battery life by allowing longer idle times without the need to change application software, without compromising user experience or affecting application functionality.

Currently, TCP connections established by smartphone agents may be persistent and non-persistent. Inactive non-persistent connections that are terminated by the server cause network resources such as cellular radio to transition from an idle state to an active state. This phenomenon repeatedly affects power consumption. Embodiments of the present invention increase the battery life of a client device by optimizing TCP connection termination by a server.

The embodiments of the present invention described below show various methods of controlling and terminating an inactive, non-persistent TCP connection on the client side, ie, at the end of the smartphone. Methods according to embodiments of the present invention allow to reduce power consumption caused by a TCP connection termination process initiated by a server by using a minimum number of wireless state transition opportunities.

According to embodiments of the present invention, the TCP connection termination processing method includes a proactive TCP connection termination method 710 and a delayed TCP connection batching termination method 720 as shown in FIG. 7 to be described later, It includes a combined leading and packed TCP connection termination scheme 730.

Embodiments of the present invention focus on improving battery life by controlling server-initiated TCP connection termination while ensuring that overall functionality remains the same as before adjustment.

Embodiments of the present invention reduce dependence on servers terminating TCP connections, and can be applied to any application that has a specific and different server termination timeout. Embodiments of the present invention have the additional advantage of minimizing network resources on the client side and do not require additional support from network side elements. Since embodiments of the present invention are independent of network support, these embodiments may be used quickly.

Embodiments of the present invention begin with capturing TCP connection information at the application transparent layer after classification of TCP connections for persistent and non-persistent connections is performed. The method used to achieve high precision and accuracy of this classification is based on monitoring the amount of time a TCP connection attempts to re-establish a connection after the connection is terminated.

A persistent connection is determined for a connection in which data exchange between a client and a server is always possible by using one or more consecutive TCP connections.

Exemplary steps for detecting non-persistent connections may be, but are not limited to:

1) the lifetime of the connection is longer than a predetermined time,

2) A similar TCP connection is re-established within a predetermined time and a predetermined number of times after the termination of the previous TCP connection. A similar TCP connection here means that the same host name or destination IP address or port of the connection is in the cache or DB.

Embodiments of the present invention are to dynamically compute various attributes from an ongoing TCP connection. These attributes can be, but are not limited to, one or more or a combination of the following:

1) Server close timeout: As shown in FIG. 6A , the server close timeout value 612 is the time required between the last data transmission and the shutdown initiated by the server 200 .

a) Last data transmission indicates the time (T25) at which the final response (to the corresponding client request) from the server 200 was received.

b) The end initiated by the server 200 indicates the time (T30) at which the TCP FIN packet was received from the end initiated by the server 200.

2) Guard timeout: As shown in FIG. 6B, the guard timeout 622 value is the fastest after the last data transmission after there is no more data transmission between the server 200 and the specific application 100-1 of the client. It's time. Here, the earliest time since the last data transmission represents the prediction result of the inactivity time after the continuous request and the corresponding response (T85, T90).

Embodiments of the present invention consider, but are not limited to, an optimal method for calculating the server shutdown timeout 612 as follows.

How to detect server shutdown timeout:

6A illustrates a method for detecting a TCP connection termination time initiated by a server according to an embodiment of the present invention. According to one embodiment of the present invention, the server initiated termination action is triggered by the server after a prolonged deactivation of data transmission.

The TCP server shutdown timeout for each connection is calculated by monitoring the so-called POLLRDHUP event in the poll system call. The POLLRDHUP event is triggered when a peer disconnects from it. That is, the POLLRDHUP event is triggered when the remote end of the connection (eg, server 200) transmits a TCP FIN packet (T30 in FIG. 6A ).

Exemplary algorithm:

Server Close Time-out = connection established time - POLLRDHUP event triggered time (FIN receiving time)

Embodiments of the present invention consider, but are not limited to, an optimal method for calculating the guard timeout as follows.

How to detect a guard timeout:

6B illustrates a method for detecting a guard timeout according to another embodiment of the present invention. According to an embodiment of the present invention, a data transmission completion time or deactivation time for non-persistent connections between a server and a mobile application is calculated as a function of a round trip time (RTT) and a response processing time.

The guard timeout is the amount of time a TCP connection socket is protected from termination initiated by the client. This can be referred to as a "protected timeout" for the socket.

The calculation of the guard timeout is a function of the application processing time for the server's response (processing time N in FIG. 6B) and the request/response round trip time (RTT M), that is, the delay between the request and the response.

The guard timeout value is different for each socket. It is dynamically updated based on socket read & write timestamps over the lifetime of the socket.

Exemplary algorithm:

Guard Timeout = Avg Processing Time + (Processing Time Variance) + Avg RTT (Avg RTT) + (RTT Variance)

example formula

Calculation Details:

Processing Time = Request Transmission Time - Last Response Received Time

RTT = Response Received Time - Last Request Transmitted Time

Average Processing Time = sum of processing times/number of processing periods

Processing Time Variance = Variance from Average Processing Time

Average RTT (Average RTT) = sum of RTTs/number of RTTs

RTT Variance = Variance from mean RTT

W ₁ = weighting factor for variance of processing time

W ₂ = weighting factor for RTT variance

4 illustrates a block configuration of a client device according to various embodiments of the present invention. For example, the client device may be the client 100 shown in FIG. 1 .

Referring to FIG. 4 , the client 100 includes an antenna unit 110 , a transceiver 120 , a controller 130 , and a memory 140 .

The antenna unit 110 transmits a signal transmitted by the transceiver 120 through a wireless channel and receives a signal on the wireless channel. The antenna unit 110 may include a plurality of antennas, an array antenna, or antenna elements for supporting beamforming.

The transceiver 120 transmits and processes a signal to be transmitted, and also receives and processes a received signal. For example, the transceiver 120 performs a conversion function between a baseband signal and a bit stream according to a physical layer standard of a system. When transmitting data, the transceiver 120 generates complex symbols by encoding and modulating the transmitted bit stream. In this case, the transceiver 120 may map the complex symbols to subcarriers and generate OFDM symbols through an inverse fast Fourier transform (IFFT) operation. When receiving data, the transceiver 120 restores a received bit stream by demodulating and decoding the baseband signal. In addition, the transceiver 120 up-converts the baseband signal into a radio frequency (RF) band signal, transmits it through the antenna unit 110, and downconverts the RF band signal received through the antenna 110 into a baseband signal. For example, the transceiver 120 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital to analog converter (DAC), an analog to digital converter (ADC), and the like.

In addition, the transceiver 120 may include multiple RF chains. In addition, the transceiver 120 may support beamforming. For beamforming, the transceiver 120 may adjust the phase and magnitude of each of signals transmitted and received through a plurality of antennas or antenna elements included in the antenna unit 110 . In addition, the transceiver 120 may perform precoding on a plurality of data streams to be transmitted. Accordingly, the transmitting device may perform MU-MIMO communication. The transceiver 120 transmits and receives signals as described above. The transceiver 120 may be referred to as a communication unit or a transceiver unit, and in some cases, may be illustrated as being separated into a transmitter and a receiver or a transmitter and a receiver.

The memory 140 stores data such as a basic program, an application program, and setting information for the operation of the transmitter. In addition, the memory 140 provides stored data according to the request of the controller 130 . For example, the memory 140 may store programs and/or instructions related to performing low-power TCP connection termination operations according to the flows illustrated in FIGS. 11 to 15 .

The controller 130 controls overall operations of the client. For example, the controller 130 transmits and receives a signal through the transceiver 120 . In addition, the controller 130 writes data to the memory 140 and reads the data recorded in the memory 140 . To this end, the controller 130 may include at least one processor.

For TCP connection control according to embodiments of the present invention, the controller 130 includes a timeout calculation module 132 and a TCP connection termination module 134 . The timeout calculation module 132 calculates or estimates a server-initiated TCP connection termination time and a guard timeout (or data transmission deactivation time) for each TCP connection for a low-power TCP connection termination operation according to embodiments of the present invention. . For example, the timeout calculation module 132 detects the server-initiated TCP connection termination time according to the flow shown in FIG. 6A . In addition, the timeout calculation module 132 detects a guard timeout according to the flow shown in FIG. 6B .

The TCP connection termination module 134 performs low-power TCP connection termination operations according to embodiments of the present invention. In an embodiment, the TCP connection termination module 134 performs a TCP connection prior termination operation according to a flow illustrated in FIG. 13 to be described later. In another embodiment, the TCP connection termination module 134 performs a TCP connection bundle termination operation according to a flow illustrated in FIG. 14 to be described later. In another embodiment, the TCP connection termination module 134 performs a TCP connection prior termination and bundle termination combining operations according to a flow illustrated in FIG. 15 to be described later.

According to an embodiment of the present invention, the controller 130 determines a data transmission deactivation time for at least one TCP connection among a plurality of TCP connections, and terminates the TCP connection at the data transmission deactivation time.

In one embodiment, the data transmission deactivation time includes a round-trip time (RTT) from transmission of a series of requests related to the TCP connection with the server to reception of a response, and after receiving any response from the server. It may be determined based on the processing time until the next request transmission.

In one embodiment, the data transmission deactivation time is earlier than the termination time for the TCP connection initiated by the server. The termination of the TCP connection initiated by the server may be performed in response to receiving a message indicating termination of the TCP connection from the server.

According to another embodiment of the present invention, the controller 130 checks at least one first TCP connection for which termination processing is initiated by the server among a plurality of TCP connections, and at least among the TCP connections except for the first TCP connection The first TCP connection is bundled and terminated together with the processing of one second TCP connection.

In an embodiment, the processing for the second TCP connection may include one of connection processing and termination processing for the second TCP connection, and data packet transmission/reception processing.

In an embodiment, the controller may perform an operation of confirming the first TCP connection in response to receiving a termination message from the server among the plurality of TCP connections.

In an embodiment, the controller checks the first TCP connection when a data transmission deactivation time for the first TCP connection is greater than a predetermined reference time, and performs an operation of tying up and terminating the first TCP connection can do. The controller may further perform the operation of terminating the first TCP connection at the data transmission deactivation time when the data transmission deactivation time is not greater than the reference time.

In one embodiment, the data transmission deactivation time includes a round-trip time (RTT) from transmission of a series of requests related to the first TCP connection with the server to reception of a response, and any arbitrary number from the server. It may be determined based on the processing time from the reception of the response until the transmission of the next request.

In an embodiment, the data transmission deactivation time may be earlier than an end time for the first TCP connection initiated by the server. The termination of the first TCP connection initiated by the server may be performed in response to receiving a message indicating termination of the first TCP connection from the server.

5 illustrates an overall software architecture 500 for a low power transmission control protocol (LPTCP) in accordance with various embodiments of the present invention. For example, this architecture 500 may be controlled by the controller 130 shown in FIG. 4 . 5 illustrates the network software components used by applications and the use of an LPTCP solution in a system, according to an embodiment of the present invention.

Referring to FIG. 5 , architecture 500 includes an application 510, a TCP connection monitor (or wrapper) 520, a TCP connection controller 530, and a socket layer library (or Includes LIBC (Library for C) 540 and Kernel 550. Although embodiments of the present invention are implemented using a system including a TCP connection monitor 520 and a TCP connection controller 530, the scope of the present invention is not limited thereto.

As shown in FIG. 5 , all network transports occur on the socket layer library 540 . The TCP connection monitor 520 is a wrapper on the socket layer library 540, for example LIBC.

The role and task of the TCP connection monitor 520 may be, but is not limited to, as follows.

a) The TCP connection monitor 520 may monitor socket call (ie, socket, end, read, write, send/send to, receive/receive from, getaddrinfo) operations.

b) TCP connection monitor 520 checks, as a return value, POLLRDHUP indicating a stream socket peer terminated connection, or calls a poll() function to shut down the writing of half of the connection By calling it, you can identify a TCP connection termination initiated by the server.

c) TCP connection monitor 520 may identify TCP connection termination initiated by the server by monitoring TCP connection state change to CLOSE_WAIT or LAST_ACK state.

d) TCP connection monitor 520 may perform shutdown of TCP connection.

e) The TCP connection monitor 520 may initiate termination of the TCP connection in a stand-alone mode.

f) TCP connection monitor 520 may be a wrapper for socket calls (which may be in the LIBC library).

g) TCP connection monitor 520 may be a modified socket layer.

The TCP connection controller 530 is an independent process used on the smartphone. The TCP connection controller 530 interacts with the TCP connection monitor 520 as a decisive unit to notify of the decision and time to proactively terminate an inactive TCP connection.

The roles and duties of the TCP connection controller 530 may be as follows, but are not limited thereto.

a) The TCP connection controller 530 may initiate a notification for terminal-side termination of a TCP connection.

b) TCP connection controller 530 may coordinate TCP connection bundle terminations for one or more TCP connection monitors with a connection or termination function for any TCP connection invoked.

c) TCP connection controller 530 monitors the network layer through a raw socket packet capture library (i.e., libpcap) for one or more TCP connection monitors along with any transmitted or received data packets. Connection bundle terminations are configurable.

d) TCP connection controller 530 may coordinate TCP connection bundle terminations to one or more TCP connection monitors with any transmitted or received data packets by monitoring packet count changes in network statistics.

Embodiments of the present invention include, but are not limited to, the following methods for achieving better battery life compared to power consumption due to TCP connection termination, which is randomly initiated by a server. As mentioned above, the TCP connection termination processing method according to the embodiments of the present invention includes a proactive TCP connection close method 710 and a delayed TCP connection bundle termination as shown in FIG. 7 , as shown in FIG. 7 . connection close method 720; and combined proactive and batching TCP connection close method 730.

Proactive TCP connection close :

3A illustrates the operation of proactive TCP connection termination according to an embodiment of the present invention. This termination operation may be initiated at the client 100 shown in FIG. 1 .

Referring to FIG. 3A , inactive TCP connections 41-43 are proactively terminated, which does not result in any additional radio state transitions. This is because the period for the termination operation of TCP connections 41-43 can be set as the minimum time of the radio activation period. According to this embodiment, inactive, non-persistent TCP connections (eg 41-43) are first terminated at the client device. The client device calculates a server timeout for the TCP connection where termination of server initiation occurred, and terminates immediately before the calculated server timeout for TCP connections that have been inactive for a period of time that can be safely terminated.

App-A, App-B, and App-C 10 simultaneously initiate a data synchronization operation ( 20 ). Due to the data synchronization activation, the radio state is transitioned from the idle state to the active state only once (60). For example, according to this embodiment, as shown in FIG. 2 , the number of radio state transitions over four times is reduced to one. In an active radio state, power consumption is maintained until the state is active. Using this opportunity, the TCP connection controller 530 of FIG. 5 closes established still inactive TCP connections 41-43.

In contrast, referring to FIG. 2 which shows the operation of termination for a TCP connection at the client initiated by the server, for the termination operation of TCP connections 41-43 for three applications 10, the idle state There are four instances 51-54 of the radio state change from to active state. As such, as the number of changes in the wireless state increases, power consumption in the client will increase.

The guard timeout as described above is a decisive attribute that determines the proactive TCP connection termination action according to an embodiment of the present invention from data transmission in progress.

9A illustrates steps 900 performed for a proactive TCP connection termination operation according to an embodiment of the present invention. For this operation, there is an interaction between the TCP connection controller 910 and the TCP connection monitor 920 on the application side.

As shown in Fig. 9A, the TCP connection monitor 920 and the TCP connection controller 910 interact according to the following communication steps.

a) The TCP connection monitor 920 with an expired guard timeout registers a proactive TCP termination with the TCP connection controller 910 (931,932).

b) TCP connection controller 910 waits for a TCP connection or termination (933-1), a new packet transaction (933-2), or waits for a timeout expiration (933), and once it occurs, it proactively terminates it to the TCP connection monitor 920 The message is sent (934).

9B illustrates steps 950 performed for a proactive TCP connection termination operation according to another embodiment of the present invention. This operation takes into account the scenario where the TCP connection controller 910 is not available. Standalone mode can be deployed as part of an application scope.

Referring to FIG. 9B , the TCP connection monitor 920 has a function of initiating a proactive TCP connection termination in a standalone mode. A TCP connection monitor 920 with an expired guard timeout 940 performs a proactive TCP connection termination 940 .

batching delayed TCP connection closes :

3B illustrates the operation of delayed TCP connection bundle termination according to an embodiment of the present invention. This embodiment discloses that a plurality of TCP connections 41-43 are terminated as a bundle for inactive, non-persistent connections. This embodiment prevents repeated wireless state transitions from the idle state to the active state as shown in FIG. 2 .

This embodiment causes a single wireless transition 72 from the idle state to the active state to terminate a plurality of TCP connections 41-43 in batches. According to this embodiment, an inactive non-persistent TCP connection is terminated concurrently with other TCP connections. When the TCP connection that caused server-initiated termination is deactivated, the inactive TCP connections (eg 41) are terminated together when a connection or termination of another TCP connection (eg 42-43) occurs.

Referring to FIG. 3B , App-A, App-B, and App-C 10 simultaneously initiate a data synchronization operation 20 . Due to the data synchronization activation, the wireless state transitions from the idle state to the active state (71). However, due to various data transmission deactivation times, the TCP connection termination can be delayed independently.

The guard timeout value depends on each 41-43 of each TCP connection of each of applications 10. Accordingly, bundling all of the TCP connections 41-43 together prevents multiple wireless state transitions (30). For example, according to this embodiment, as shown in FIG. 2 , the number of radio state transitions over four times is reduced to two.

10A and 10B illustrate steps 1000-1 and 1000-2 performed in a bundle termination operation for delayed TCP connections according to an embodiment of the present invention. For this operation, there is some interaction between the TCP connection controller 1010 and the TCP connection monitor 1021-1023 in the application process.

As shown in Figures 10a and 10b, the TCP connection monitor 1010 and the TCP connection controller 1021-1023 interact according to the following communication steps:

a) TCP connection monitors 1021-1023 having expired guard timeout register TCP bundle termination to TCP connection controller 1010 almost simultaneously (steps 1 1000-1 and 1031-1034 of FIG. 10A ).

b) TCP connection controller 1010 waits for TCP termination or minimum server timeout (step 2 1000-2, 1035 in FIG. 10b), and once it occurs, sends a bundle termination message (1036).

c) After receiving the TCP bundle termination message from the TCP connection controller 1010, the TCP connection monitors 1021-1023 terminate the TCP connections as a bundle.

combined proactive and batching TCP connection close :

8 is a diagram for explaining a combined operation of TCP connection precedence and bundle termination according to an embodiment of the present invention.

This action includes a combination of the TCP connection preemptive termination method and the TCP connection bundle termination method. A client device terminates an inactive non-persistent TCP connection before server-initiated termination occurs, or terminates an inactive non-persistent TCP connection concurrently with the creation or termination of another TCP connection. The client device normally operates in an advance termination mode. If the radio tail is expected to be greatly extended due to the preceding termination, the client device operates in the bundled termination mode. For example, if t _GuardTimeout > t _{InactivityTimer} , the client device operates in the batch shutdown mode. As another example, when t _GuardTimeout < t _LowPower , the client device operates in the advanced shutdown mode. This embodiment corresponds to a form in which the power saving benefits of the two embodiments are fully accumulated. A predetermined guard timeout value is used for this embodiment.

11 illustrates an overall flow between a TCP connection monitor 1102 and a TCP connection controller 1104 for a TCP control method according to various embodiments of the present invention. TCP Connection Monitor 1102 performs the following steps:

1) The TCP connection monitor 1102 hooks socket application program interfaces (APIs) such as socket, connection, read, and write ( 1111 ).

2) The TCP connection monitor 1102 checks whether it is a socket for a TCP socket (1112). If so, go to step 1113, otherwise go to step 1116.

3) TCP connection monitor 1102 creates a new entry in the scope of TCP connection monitor when a socket is newly created, otherwise, it uses meta such as timestamp, guard timeout, server timeout, etc. ) is updated (1113).

The TCP connection monitor 1102 updates TCP metadata to the TCP connection controller 1104, which bundles the TCP termination (1122).

The TCP connection monitor 1102 goes to step 1114 if the connection is a server-initiated termination, otherwise it goes to step 1116.

4) The TCP connection monitor 1102 calculates a guard timeout based on the time stamp of the TCP socket read/write operation, and triggers a timer to notify the guard timeout ( 1114 ).

5) The TCP connection monitor 1102 terminates the TCP connection once the guard timeout has expired or a bundle termination notification is received from the TCP connection controller 1104 ( 1115 ).

6) The TCP connection monitor 1102 calls the corresponding LIBC (Library for C) API (1116).

TCP connection controller 1104 performs the following steps:

1) The TCP connection controller 1104 waits for a request from the TCP connection monitor 1102 (1121).

2) When a request is received from the TCP connection monitor 1102, the TCP connection controller 1104 creates a memory entry of the TCP connection monitor 1102 or updates an existing entry (1122).

3) The TCP connection controller 1104 determines a bundle termination approach method, and multicasts a TCP termination notification to the TCP connection monitor 1102 ( 1115 ).

12 illustrates a flow 1200 of an operation for calculating a data transmission inactivity time or guard timeout, according to an embodiment of the present invention. For example, this flow may be performed by the TCP connection monitor 1102 and the TCP connection controller 1104 shown in FIG.

1) In step 1210, socket APIs such as socket, connection, lead, and light are hooked.

2) In step 1220, it is checked whether the socket is a TCP socket. If the TCP socket is verified, proceed to step 1230, otherwise go to step 1260.

3) In step 1230, TCP meta information such as server IP, port, domain name, and server timeout is created/updated.

4) In step 1240, a guard timeout is calculated based on the time stamp of the TCP socket read/write operation.

5) In step 1250, the TCP connection meta, that is, the guard timeout in the local cache is updated.

6) In step 1260, the corresponding LIBC API is called.

13 shows an operational flow 1300 of TCP control for a method for proactively terminating an inactive, non-persistent TCP connection, according to an embodiment of the present invention. For example, this flow may be performed by the TCP connection monitor 1102 and the TCP connection controller 1104 shown in FIG.

1) In step 1310, a guard timeout is dynamically calculated based on a TCP socket read/write operation, and a timer is set to notify the expiration of the guard timeout.

2) In step 1310, if the socket read/write occurs in the middle, the timer is reset.

3) In step 1320 , expiration of the guard timeout is queued.

4) In step 1330, the TCP connection is terminated.

FIG. 14 shows an operational flow 1400 of TCP control for a bundle termination method for an inactive, non-persistent TCP connection, according to an embodiment of the present invention. For example, this flow may be performed by the TCP connection monitor 1102 and the TCP connection controller 1104 shown in FIG.

1) In step 1410, a guard timeout is dynamically calculated based on the TCP socket read/write operation, and a timer is set to notify the expiration of the guard timeout.

2) In step 1410, if it occurs in the middle of the socket read/write, the timer is reset.

3) In step 1420, expiration of the guard timeout is queued.

4) In step 1430, if the guard timeout is longer than the normal value or the reference value, the bundle termination is registered together with the data packet or control packet from another TCP connection.

5) In step 1440, a notification to end the bundle processing from the TCP connection controller 1104 is queued.

6) In step 1450, when a bundle termination notification is received from the TCP connection controller 1102, the TCP connection monitor 1102 terminates the TCP connection.

15 illustrates an operational flow 1500 of TCP control for combined methods including proactive and bundle termination for inactive, non-persistent TCP connections, according to an embodiment of the present invention. For example, this flow may be performed by the TCP connection monitor 1102 and the TCP connection controller 1104 shown in FIG.

a) In step 1510, the guard timeout for the TCP connection is updated in the TCP connection monitor 1102.

b) After the guard timeout expires in step 1520, the guard timeout value is compared with a predetermined reference time or a network inactivation timer value in step 1530. Expiration of the guard timeout is assumed to be the beginning of network inactivity.

c) If the guard timeout is less than a predetermined threshold, a proactive TCP connection termination operation is performed in step 1560 .

d) If the guard timeout is greater than the predetermined threshold, in step 1540, for other in-progress connections, a bundling request is registered with the TCP connection controller 1104 .

e) In step 1540, a notification of ending the bundle processing from the TCP connection controller 1104 is awaited.

f) In step 1550, when a bundle termination notification is received from the TCP connection controller 1102, the TCP connection monitor 1102 terminates the TCP connection.

16A and 16B show test results 1610 and 1620 in terms of power saving for a low power transmission control protocol (LPTCP) termination operation according to various embodiments of the present disclosure.

16A and 16B , it can be seen that the LPTCP termination operation according to various embodiments of the present invention saves about 17% of power in a mobile terminal such as a smart phone compared to the conventional TCP operation.

17 illustrates test results 1710 and 1720 in terms of network signaling reduction for a TCP control operation according to various embodiments of the present disclosure. This test result is the result obtained through the connection analyzer (connection analyzer) 1700.

Referring to FIG. 17 , according to the LPTCP termination operation according to various embodiments of the present invention, the signaling load 1710 is reduced by 16.2% (136 --> 114), and the time 1720 in the connected state is 25.8% (29 minutes 32 minutes) Seconds --> 21 minutes 54 seconds) is decreased.

As described above, various embodiments of the present invention provide a longer idle time without deteriorating user experience or affecting application functions without the need to change application software in a client device such as a smartphone terminal. to help achieve higher battery life.

Meanwhile, although specific embodiments have been described in the detailed description of the present invention, various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments and should be defined by the claims described below as well as the claims and equivalents.

Claims (24)

delete delete delete delete In a method of operating a client in a wireless communication system:
A process of identifying a first transmission control protocol (TCP) connection and a second TCP connection established by the client, wherein the first TCP connection is a connection different from the second TCP connection,
identifying the initiation of a close for the first TCP connection, the first TCP connection being maintained in response to the initiation of the close for the first TCP connection;
identifying the initiation of a close for the second TCP connection during the maintenance of the first TCP connection after the initiation of the close of the first TCP connection;
and closing both the first TCP connection and the second TCP connection in response to the initiation of the close for the second TCP connection.
6. The method of claim 5, wherein a guard time period of the first TCP connection is greater than a predetermined reference time.
The method according to claim 5, wherein the process of identifying the first TCP connection comprises:
and identifying the first TCP connection in response to receiving a close message from a server.
delete The method according to claim 5, wherein when a guard time period of the first TCP connection is not greater than a predetermined reference time, the first TCP connection is terminated at the end of the guard time period. A method that further includes the process of
The method according to claim 6 or 9, wherein the guard time period is determined based on a first time period and a second time period,
The first time interval is a time period from a transmission time of a request to a reception time of a response corresponding to the request,
The second time interval is a time interval from the reception time of the response to a transmission time of a next request.
The method according to claim 6 or 9, wherein the guard time period (guard time period),
A method earlier than an end point for the first TCP connection initiated by the server.
12. The method of claim 11, wherein the termination for the first TCP connection initiated by the server comprises:
A method performed in response to receiving a message indicating termination of the first TCP connection from the server.
delete delete delete delete In a client of a wireless communication system,
A controller comprising: the controller
Identifies a first transmission control protocol (TCP) connection and a second TCP connection established by the client, wherein the first TCP connection is a connection different from the second TCP connection,
identify initiation of a close for the first TCP connection, wherein the first TCP connection is maintained in response to the initiation of the close for the first TCP connection;
identify the initiation of a close for the second TCP connection during the maintenance of the first TCP connection after the initiation of the close of the first TCP connection;
and closing both the first TCP connection and the second TCP connection in response to the initiation of the close for the second TCP connection.
18. The method of claim 17,
A guard time period of the first TCP connection is greater than a predetermined reference time.
The method according to claim 17, The controller,
A client identifying the first TCP connection in response to receiving a close message from a server.
delete The method according to claim 17, The controller,
When a guard time period of the first TCP connection is not greater than a reference time, the client further performs the operation of terminating the first TCP connection at the end of the guard time period.
22. The method of claim 18 or 21,
The guard time period is determined based on a first time period and a second time period,
The first time interval is a time period from a transmission time of a request to a reception time of a response corresponding to the request,
The second time interval is a time interval from the reception time of the response to a transmission time of a next request.
The method according to claim 18 or 21, wherein the guard time period (guard time period),
A client earlier than the end time for the first TCP connection initiated by the server.
24. The method of claim 23, wherein the termination for the first TCP connection initiated by the server comprises:
A client performed in response to receiving a message indicating termination of the first TCP connection from the server.

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