KR20150123185A - Apparatus and method for transferring data using multipath transmission control protocol - Google Patents

Abstract

Disclosed is a method for transmitting data between a first device and a second device by using a multipath transmission control protocol (MPTCP) connection. The method includes the processes of: receiving the data which is currently in use, is to be transmitted, and includes a set of data units from the first device; and extracting priority-related information regarding the data units from the received data. Also, the method includes the processes of: processing the priority-related information in order to allocate each data unit to one of multiple sub-flows in the MPTCP connection; and using the sub-flows allocated with the data units to transmit the data units being in use to the second device through the MPTCP connection.

Description

[0001] APPARATUS AND METHOD FOR TRANSFERRING DATA USING MULTIPATH TRANSMISSION CONTROL PROTOCOL [0002]

The present invention relates to an apparatus and method for transmitting data using a Multipath TCP (MPTCP) connection.

MPTCP provides a mechanism for simultaneously using multiple interfaces to a single session while maintaining a standard Transmission Control Protocol (TCP) socket application programming interface (API) for the application. Is the evolution of TCP standardized by the Internet Engineering Task Force, which grants the use of TCP. The use of multiple interfaces to create parallel sub-flows can improve resource utilization and increase redundancy, thereby increasing the session aggregate throughput. In addition, the use of the multiple interfaces for creating the parallel sub-flows may contribute to smooth handover and to balancing the traffic load between multiple interfaces in a congested network. MPTCP is particularly useful in mobile wireless networks where mobile telephones have one or more interfaces to the Internet, as well as throughput enhancements introduced by introducing MPTCP to data centers and multihomed servers. It is common use case to use both Wi-Fi ™ and mobile network 3G / LTE (Long Term Evolution). In addition to the expected gains in throughput due to the increased aggregation bandwidth, the MPTCP can improve the robustness to disconnection due to user movement.

Figure 1 shows the client 100 (mobile handset UE) receiving data from the server 102 AS, via two interfaces Wi-Fi ™ 104 and 3G / LTE modem 106, Shows a system schematic of an exemplary MPTCP connection for uploading files, images, videos or web pages. Thus, two sub-flows, one sub-flow via Wi-Fi (TM) hotspot and the other sub-flow via E-UTRAN are created. Since the two paths are in contact with other network topologies and proceed through various middlebox constraints, the two generated sub-flows have different capabilities and Round Trip Time : RTT). Important tasks of MPTCP include how to operate based on network congestion state, route totes, receiver buffer availability space, and how much data needs to be allocated to each sub-flow.

In some applications and services, such as SPDY (TM), the data segments are prioritized in such a way that high priority data is sent first to improve the browsing experience. Pushing the prioritized data to an MPTCP buffer where the MPTCP does not recognize the significance and significance of the segment is particularly important when pushing some of the high priority segments over the lost channel Transmission can be made less efficient and the channel is able to successfully send a high priority data (such as the HTML file needed to construct the document object model (DOM) at browsing) .

For more efficient transmission, it would be advantageous for the MPTCP to be aware of the importance of the packets so that congestion control can push the higher priority packets to the more robust and less lossful sub-flows. As far as the present inventors are aware, no research in the literature has referred to this cross-layer operation and how MPTCP can classify sub-flows and offload the prioritized data to the sub-flows there was.

Embodiments of the present invention are intended to at least address some of the problems as described above. Embodiments of the present invention may provide mechanisms for MPTCP based data transmission systems that classify sub-blobs useful for reflecting switched prioritized packets from the session layer. Embodiments of the present invention may also manage the common buffer to offload the prioritized data to appropriate sub-flows.

According to a first aspect of the present invention there is provided a method of transmitting data between a first device and a second device using a Multipath Transmission Control Protocol (MPTCP) connection, the method comprising:

Receiving data to be transmitted in use, the data including a set of data units from the first device;

Extracting priority-related information for the data units from the received data;

Processing the priority-related information to assign each of the data units to one of a plurality of sub-flows of the MPTCP connection;

And transmitting the data units in use to the second device over the MPTCP connection using the assigned sub-flows.

The processing of the priority-related information may include analyzing the data units to assign one of a plurality of priority levels to each of the data units.

The method may further comprise analyzing the sub-flows of the MPTCP connection to assign one of a plurality of quality classes to each of the sub-flows.

In addition, the processing of the priority-related information may further include allocating the data units to the sub-flows so that data units having a certain priority level are allocated to sub-flows having a specific quality class have.

The method may further comprise applying a congestion control process to each of the sub-flows of the data units transmitted from the buffer. The congestion control process may include a combined MPTCP congestion control mechanism.

The processing of the priority-related information may be based on at least one data transmission quality-related factor of the sub-flows, such as loss rates and / or other parameters such as RTT and ACKs, Into the quality classes, e.g., low and high quality classes. A subflow with a high quality class may be robust but may include a non-lost subflow (e.g., with a low expected retransmission rate). A sub-flow having a lower quality class may include a sub-flow that does not require repetitive retransmission of the data units.

The processing of the priority-related information may include calculating a loss rate of a sub-flow, and allocating a quality class to the sub-flow based on the calculated loss rate. Calculating a loss rate of the sub-flow comprises:

Transmitting a plurality of data units using each sub-flow;

Recognizing the number of lost data units (e. G., Non-acknowledged data units (NACK)) within the time window T for each sub-flow;

And calculating an average loss rate LR _i within a time window for each of the sub-flows.

The process of calculating the average loss rate LR _i may use the following equation:

The classifying the sub-flows into the quality classes may include aligning the sub-flows based on the calculated average loss rate LR _i of each sub-flow. In some embodiments, a subflow having a reference value, e.g., a calculated average loss rate LR _i of less than 1%, is classified as a high quality class subflow.

The process of analyzing the subflows comprises:

Calculating an expected transfer time to transfer a plurality of high priority level data units through a plurality of combinations of subgroups of the subflows;

Classifying the sub-flows in the sub-group having the lowest expected delivery time into a high quality class.

The process of calculating the expected delivery time comprises:

Attempting delivery of the plurality of data units through a subgroup of sub-flows;

Performing repetitive transmission of the plurality of data units,

And calculating a corresponding window for each sub-flow at each round trip time (RTT).

The process of analyzing the sub-flows may be performed dynamically according to the conditions of the network used for changing the MPTCP connection.

The analyzing of the data units may include extracting priority-related information for the data units from the received data. The process of extracting the priority-related information may process cross layer information such as information on data units crossing between a session layer and a transport layer . The step of analyzing the data units may include analyzing the priority flags / signals of the data units. In some embodiments, analyzing the data units comprises analyzing the relevance order of the data units.

The data unit may include an SPDY (TM) message. The process of analyzing the data units may include assigning a high priority level to a data unit comprising a SPDY (TM) message having a SYN_STREAM or SYN_REPLY high priority identifier.

The data may comprise video data, wherein each data unit is categorized into an I-frame, a P-frame, or a B-frame. The process of analyzing the data units may include assigning a high priority level to a data unit including an I-frame, and assigning a low priority level to the data unit including the P-frame or the B-frame. .

The step of arranging the data units in the buffer includes forward loading data units having a high priority level to the buffer, and backward loading data units having a low priority level into the buffer. loading process. The step of arranging the data units in the buffer prevents further loading of the data units having the lower priority level into the buffer when the remaining space of the buffer is sufficient for loading the data units having the higher priority level Process.

The MPTCP connection may use multiple communication network interfaces. The communication networks may include wireless networks, e.g., LTE and Wi-Fi. The method may include establishing an MPTCP connection between the first device and the second device. The MPTCP connection may include multiple, e.g., two, subflows.

According to another aspect of the present invention, there is provided a system for transmitting data between a first device and a second device via a Multipath Transmission Control Protocol (MPTCP) connection, the system comprising:

A device configured to receive in-use data to be transmitted, the device comprising a collection of data units from the first device;

An analyzer configured to extract priority-related information for the data units from the received data;

A processing device configured to process the priority-related information to assign each of the data units to one of a plurality of sub-flows of the MPTCP connection;

And a data transfer device configured to transfer the in-use data units to the second device over the MPTCP connection using the assigned sub-flows.

The analyzer may be logically located within the Android framework and the processing device may be logically located within the Linux kernel.

The MPTCP connection may use at least one wireless network, for example a 3G / LTE or Wi-Fi ™ network.

According to yet another aspect of the present invention there is provided a computer readable medium storing a computer program that substantially operates the method described herein.

According to yet another aspect of the present invention, there is provided a method of transmitting data between a first device and a second device using an MPTCP connection, the method comprising:

Receiving data to be transmitted in use, the data including a set of data units from the first device;

Analyzing the data units to assign one of a plurality of priority levels to each of the data units;

Analyzing the sub-flows of the MPTCP connection to assign one of a plurality of quality classes to each sub-flow;

Assigning the data units to the sub-flows to allow data units having a certain priority level to be assigned to a sub-flow having a corresponding quality class;

Arranging the data units in the buffer of the MPTCP connection according to the assigned priority levels of the data units;

And transmitting the arranged data units in use from the buffer to the second device using the allocated sub-flows.

The processing of the priority-related information comprises:

Determining from the priority-related information whether the data unit has a low priority level or a high priority level;

Assigning the data unit having the low priority level to a subflow having a high priority data transmission classification;

And allocating the data unit having the high priority level to a subflow having a low priority data transmission classification.

The method may further include classifying the sub-flows of the MPTCP connection into sub-flows having a high-quality data transmission class, or classifying them into sub-flows having a low-quality data transmission class.

According to the present invention, a method, an apparatus and a system as described in the appended claims are provided. Other features of the invention will be apparent from the dependent claims and the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the present invention and to show how embodiments of the invention may be effected, reference will now be made, by way of example, to the accompanying diagrammatic drawings in which:
Brief Description of the Drawings Figure 1 shows a system schematic of an example MPTCP connection being used for data transmission from a server to a client;
Figure 2 is a timeline illustrating data transmission from a server to a client over an MPTCP connection in accordance with an embodiment of the data transfer method of the present invention;
Figure 3 illustrates the architecture of an example MPTCP prioritized data offload mechanism deployed in a mobile device according to one embodiment of the data transfer method;
Figure 4 graphically illustrates buffer management according to one embodiment of the data transfer method;
Figure 5 graphically illustrates an important categorization of video frames according to one embodiment of the data transfer method.

Embodiments of the present invention include a packet / segment analyzer 304, a subflow coordinator 306, a buffer manager 308, and a dual congestion control 310 in the MPTCP offloading mechanism And introduces new procedures that can be FIG. 2 is a timeline diagram of the introduced procedures as the MPTCP transmission progresses between the server 300 and the client 302. FIG. It will be appreciated that the steps of FIG. 2 are exemplary only, and that in other embodiments at least some of the steps may be reordered or omitted, and / or that additional steps may also be performed.

This procedure assumes that the MTCP connection is established between a mobile handset (client 302) and a transmitter (server 300) using a plurality of activated sub-flows. Cross layer information information exchange occurs between the session layer and the transport layer to determine the prioritization level of the packets / segments and which packets / segments of the packets / segments correspond to high priority critical tasks (e.g., It will be appreciated that segments related to constructing the DOM at browsing, or I-frames at the time of video transmission, but the method may also be applied to other types of data units that may be prioritized in various manners The Packet Analyzer (PA) 304 receives the MPTCP from the segment / packets In the exemplary embodiment, the classes are classified into priority level classes based on the information to be exchanged (e.g., the priority of a segment when assuming an SPDY ™ service) : HPC) and a low priority class (LPC). However, it will be appreciated that in other embodiments, other types and / or multiple priority level classes may be used.

Meanwhile, the sub-flow coordinator (SC) 306 may calculate the useful sub-flows based on data transmission quality factors such as the loss rate of the useful sub-flows and / or other parameters such as RTT and / or ACKs Quality classes. Examples of the above classification procedures that can be performed by the SC are described below. The classification is performed dynamically and allows continuous and rapid rebalancing for short periods of time, e.g., based on client settings, e.g., network / wireless condition changes. In the example embodiment, two quality classes of subflows are provided. The sub-flow classes are then mapped to the HPC and LPC segments / fragments performed by the PA 304. An example mechanism for performing the above classification will be described below. In other embodiments, other types and / or multiple quality classes may be used. The data unit priority level classes, the subflow quality classes and / or the number of network interfaces associated with the MPTCP connection do not necessarily correspond to each other.

After calculating the aggregate useful subflow windows for each class, which may include assigning a specific number of high priority packets and a specific number of low priority packets contained in each window, the buffer manager The buffer manager (BM) 308 rearranges the classified packets in a common buffer of the server 300 so that the useful buffer space can be allocated to HPC and / or HPC in a fair and opportunistic manner for better buffer utilization efficiency. Lt; RTI ID = 0.0 > LPC < / RTI > segments / packets. An example of such an assignment will be described below.

Finally, two separate congestion controls 310 may be applied to each quality class as described above, and the packets may be assigned to the sub-flows according to the computed classifications. Each congestion control process may be a basic coupled MPTCP congestion control mechanism even though the two controls are not explicitly coupled and operate independently. However, since the sub-flow classification is dynamic, the sub-flows can be re-allocated regularly to other sub-flows ensuring classification of the indirect coupling between the two mechanisms.

In order for the data to be transmitted from the server 300 to the client 302, the packets are sent to the flow controller 312 of the client device, Indicating whether the space is useful for receiving the data.

The block architecture and the deployment of an example MPTCP flow control mechanism in an Android ™ mobile phone is shown in FIG. The example MPTCP flow control mechanism is implemented using two network tokens: LTE and Wireless Local Area Network (WLAN). The architecture maintains the regular MPTCP / TCP socket API 501 (assuming an established MPTCP connection between the server / transmitter and the client where two subflows are already present) A packet analyzer (PA) 304 and a subflow coordinator (SC) 306, which are located in different layers, are introduced, but using an intersection layer channel between the session and transport layers And exchanges prioritization control signals. It will be appreciated that in other embodiments, other types of networks, interfaces, transmit / receive devices may be used.

The packet analyzer (PA) 304 is introduced at the interface between the session / application layer 502 and the transport layer (and thus is logically located within the Android framework in the illustrated embodiment) do). Data relating to the priority levels of the data units to be transmitted are received and processed by the PA 304. [ An important role of the packet analyzer is to classify packets based on priority flags / signals of the exchanged packets (e.g., a high priority class (HPC) and a low priority class : LPC)). As an example, in the case of the SPDY (TM) service, the PA refers to group flags or related sequences of segments before classifying the segments.

The subflow coordinator (SC) 306 and the buffer manager (BM) 308 are coupled to the MPTCP 306, which is logically located in the Linux ™ kernel in the illustrated embodiment. Connection 504, TCPs 505A and 505B, and an IP routing component 506. As shown in FIG. The SC 306 may dynamically determine the useful sub-flows (e.g., 508A, 508B) based on quality-related factors such as the loss rate of the useful sub-flows and / or other parameters such as RTT and ACKs Quality classes, for example, HPC and LPC. In other embodiments, the data from the flow control window can be used to assign quality classes, and in general any information exchanged during transmission can be based on the classification. It will also be appreciated that other mechanisms may be used to perform the classification process.

The first example classification process is a simple classification process based on calculating the loss rate of each sub-flow. When using this example classification procedure, at the start, all sub-flows, i = 1: N sub-flows, are classified by the SC 306 into the HPC class. The SC 306 then recognizes the number of the non-acknowledged packets (NACK) within a certain time window T: typically within several RTTs for each sub-flow, The average loss rate LR _i in this time window is calculated as: < RTI ID = 0.0 >

인 서브 플로우는 HPC로 분류되고, 상기 조건에 부합되지 못하는 서브 플로우에는 상기 LPC 클래스로 할당된다.

의 대표적인 예제 값은 1%이다. After calculating all LR _i i = 1: N, the SC 306 aligns all of the sub-flows based on the loss rates of all the sub-flows. Basically,

Is classified as HPC, and a subflow that does not meet the above condition is assigned to the LPC class.

A typical example value is 1%.

An example of a more complex but more efficient classification procedure that can be performed by the SC 306 is based on calculating the expected time to deliver M high priority packets of all possible subgroups of subflows do. For each sub-flow, the SC 306 attempts to deliver M packets through the sub-group of sub-flows that each sub-flow originates from the actual state / current state of the MPTCP congestion control mechanism And then operates iterative transmission of the packets and calculates the corresponding window for each sub-flow in each RTT based on known congestion control algorithms.

In one embodiment, the buffer manager (BM) 308 allocates the classified packets to the common buffer so that HPC packets are located starting from the beginning of the common buffer, (Forward loading, LPC packets starting from the end and loading from right to left. It will be appreciated that this is only one possible buffer management example, and that other sharing mechanisms may be used. Graphically illustrates buffer management according to this method. One important aspect is that the HPC data is stored in a buffer that is loaded with no further loading of the LPC when the useful memory space is needed for HPC transmission In the case, you can always have priority.

Another embodiment is configured to process SPDY (TM) segments. SPDY (TM) divides the HTTP communication into small individual frames, which are mapped to messages in the logical stream. The stream is a virtual channel carrying bi-directional messages. Each stream has a unique integer identifier (1, 2, ..., S). Unlike HTTP 1.x, in SPDY ™, all communications are performed within a single TCP connection. To further improve SPDY ™ performance, each stream is assigned a 31-bit priority value:

. 0 represents the highest priority stream.

. 2 ³¹ -1 represents the lowest priority stream.

When rendering a page in the browser, the HTML document itself is important to the construction of the DOM because not all resources have the same priority: the Cascading Style Sheets (CSS) It is necessary to construct the CSS Object Model; Both the DOM and CSS object model configurations can be blocked in JavaScript (TM) resources, and other resources such as images are usually fetched at a lower priority. Using the priorities in space, the client and server apply various techniques to process the individual streams, messages, and frames in an optimal order by controlling the allocation of the resources (CPU, memory, bandwidth) If the response data is useful, it prioritizes delivery of high-priority frames to the client.

However, SPDY ™ is designed to fetch all segments into a single TPC connection, and is not designed for MPTCP. Implementing SPDY ™ on native MPTCP will not be optimal because it does not consider mapping prioritized segments to one or more TCP subflows. However, the inventors have developed an embodiment of the mechanism described herein to ensure that a high priority is transmitted through the set of best sub-flows as soon as possible, and the low priority segments are sent to the lost sub- By allocating, you can provide an improved mapping that can further improve SPDY ™ performance.

Priority identifiers such as SYN_STREAM and SYN_REPLY in the SPDY (TM) messages may be exchanged with the MPTCP packet analyzer 304 to classify the priority levels of the segments. The procedure as described above may then be followed by the classification process.

Other embodiments may classify the video packets based on the priority of the video packets. Video content is differentiated from generic data because encoded video packets are temporarily correlated with previously encoded video packets and the previously encoded video packets introduce interdependencies between the packets. In addition, the video packets are self-decodable or dependent-decodable depending on the capabilities of the video packets and classified into three main categories. Video packets / frames are divided into three categories: I-frames, P-frames, B-frames,

- I-frames are the least compressible frames and are not based on other video frames to be decoded

- P-frames require data from previous frames to be decoded and can achieve better compression than I-frames

Although the B-frames use previous and subsequent frames for encoding to achieve a high level of compression, the decoding process of the B-frames is based heavily on the success of decoding the packets on which the B-frames are based .

Considering this categorization, the present inventors have proposed prioritization (shown in FIG. 5) of the frames to be more important or less important based on the independence and self-decoding capability of the frames :

- I-frames may be considered more important than P-frames or B-frames because the I-frames are self-decodable and do not require any reference frames. P-frames and B-frames require I-frames to be decoded.

- P-frames may be considered more important than B-frames because the P-frames require prior successful decoding of the reference frame / packet to decode the P-frames themselves. In addition, P-frames can be used as a reference frame for encoding B-frames, so that B-frames are based on the P-frames when the B-frames refer to the P-frames.

- B-frames require previous successful decoding of the reference frames of the B-frames (which may be I-frames or P-frames) for decoding of the B-frames themselves (Or in terms of self-decoding capability) since it is less important than P-frames or I-frames.

(E.g., in one embodiment, only I-frames are considered to be significant and high priority, and both B-frames and P-frames have a low priority , The PA can classify the corresponding frames into HPC or LHC classes. The process as described above may then be allowed to complete the transmission process.

Meanwhile, although not shown in separate drawings, in one embodiment of the present invention, a server may include a transmitter, a controller, a receiver, and a storage unit.

First, the controller controls the overall operation of the server. The controller controls the server to perform the overall operation related to the operation of transmitting data using the MPTCP connection according to an embodiment of the present invention. Here, since the overall operation related to the operation of transmitting data using the MPTCP connection according to the embodiment of the present invention is the same as that described with reference to FIG. 2 to FIG. 5, detailed description thereof will be omitted.

The transmitter transmits various signals and various messages to another entity, e.g., a client, under the control of the controller. Here, various signals and various messages transmitted by the transmitter are the same as those described with reference to FIGS. 2 to 5, and a detailed description thereof will be omitted.

In addition, the receiver receives various signals and various messages from other entities, for example, clients, under the control of the controller. Here, various signals and various messages received by the receiver are the same as those described with reference to FIG. 2 to FIG. 5, and a detailed description thereof will be omitted.

The storage unit stores information related to the overall operation related to the operation of transmitting data using the MPTCP connection according to an embodiment of the present invention, such as programs and various data necessary for the operation of the server. In addition, the storage unit stores various signals and various messages received by the receiver.

In the above description, the server is implemented as separate units such as the transmitter, the controller, the receiver, and the storage unit. However, the server may include the transmitter, the controller, the receiver, It should be understood that at least two units may be integrated into one unit.

Also, although not shown in separate drawings, in one embodiment of the present invention, the client may include a transmitter, a controller, a receiver, and a storage unit.

First, the controller controls the overall operation of the client. The controller controls the client to perform the overall operation related to the operation of transmitting data using the MPTCP connection according to an embodiment of the present invention. Here, since the overall operation related to the operation of transmitting data using the MPTCP connection according to the embodiment of the present invention is the same as that described with reference to FIG. 2 to FIG. 5, detailed description thereof will be omitted.

The transmitter transmits various signals and various messages to another entity, e.g., a server, under the control of the controller. Here, various signals and various messages transmitted by the transmitter are the same as those described with reference to FIGS. 2 to 5, and a detailed description thereof will be omitted.

In addition, the receiver receives various signals and various messages from another entity, e.g., a server, under the control of the controller. Here, various signals and various messages received by the receiver are the same as those described with reference to FIG. 2 to FIG. 5, and a detailed description thereof will be omitted.

The storage unit stores information related to an overall operation related to an operation of transmitting data using an MPTCP connection according to an embodiment of the present invention, such as programs and various data necessary for the operation of the client. In addition, the storage unit stores various signals and various messages received by the receiver.

In the above description, the client is implemented as separate units such as the transmitter, the controller, the receiver, and the storage unit. However, the client includes the transmitter, the controller, the receiver, It should be understood that at least two units may be integrated into one unit.

Embodiments of the present invention may provide an efficient MPTCP transmission scheme in which priorities of data units, such as packets to be transmitted, are reflected in the offload mechanism for more optimized services. The additional flexibility in the MPTCP offloading mechanism can satisfy the settings of higher layers and the settings of the higher layers can be achieved by introducing the cross layer visibility.

Currently, clients can periodically select the best interface using heuristics, and switch every time they terminate existing connections and re-establish new connections. Embodiments of the MPTCP prioritized data offloading mechanism described herein may avoid the need to make such binary decisions and instead use continuous and fast rebalancing in a short period of time, (rebalancing).

The embodiments may not be completely visible to the middleboxes because no control signals or flags need to be generated or exchanged without changing the MPTCP transmission protocol. Also, since only cross-layer information is exchanged, no additional overhead or control data needs to be transmitted over the network.

It will be appreciated that, in accordance with a preferred embodiment of the present invention, there is provided a computer readable medium storing a computer program for operating a method according to the above embodiments.

All documents and documents filed concurrently with or in connection with this application or which have been previously filed and which are disclosed to the public within this disclosure and the contents of all such documents and documents are hereby incorporated by reference It should be noted.

All features disclosed in this specification (including any accompanying claims, abstract, drawings), and / or all steps of a method or processor disclosed in the above description may be combined with at least some of the features, and / May be combined in any combination, except for those that are mutually excluded.

Each feature disclosed in this specification (including any accompanying claims, abstract, drawings) may be replaced by other features that serve the same, equivalent, or similar purpose, unless specifically stated otherwise. Thus, unless stated otherwise, each feature disclosed is but one example of a generic series of equivalent or similar features.

The present invention is not limited to the specific details of the above-described embodiment (s). It is intended that the present invention not be limited to the novel features or novel combinations of features disclosed in this specification (including any accompanying claims, abstract and drawings), or to novel steps or steps of the method or process disclosed hereinabove, Lt; / RTI >

Claims (27)

A method for transmitting data between a first device and a second device using a Multipath Transmission Control Protocol (MPTCP) connection, the method comprising:
Receiving data to be transmitted in use, the data including a set of data units from the first device;
Extracting priority-related information for the data units from the received data;
Processing the priority-related information to assign each of the data units to one of a plurality of sub-flows of the MPTCP connection;
And transmitting the data units in use to the second device over the MPTCP connection using the assigned sub-flows. The method of claim 1, further comprising transmitting data between the first device and the second device using an MPTCP connection How to.
The method according to claim 1,
Wherein the processing of the priority-related information comprises analyzing the data units to assign one of a plurality of priority levels to each of the data units. ≪ RTI ID = 0.0 > And transferring data between the first device and the second device.
3. The method of claim 2,
Further comprising analyzing the sub-flows of the MPTCP connection to assign one of a plurality of quality classes to each of the sub-flows, using the MPTCP connection. How to transfer data.
The method of claim 3,
Wherein the step of processing the priority-related information comprises the step of allocating the data units to the sub-flows and allocating the data units having a certain priority level to the sub-flows having a corresponding quality class The method comprising: transmitting data between a first device and a second device using an MPTCP connection.
5. The method of claim 4,
Arranging the data units in a buffer according to the assigned priority levels of the data units;
And transferring the in-use arranged data units from the buffer to the second device using the allocated sub-flows. The method of claim 1, further comprising: transmitting data between the first device and the second device using the MPTCP connection How to transfer.
6. The method according to any one of claims 1 to 5,
Further comprising applying a separate congestion control process to each of the sub-flows. ≪ Desc / Clms Page number 21 >
The method according to claim 6,
Wherein the congestion control process comprises a combined MPTCP congestion control mechanism. ≪ Desc / Clms Page number 21 >
The method of claim 3,
Wherein the step of analyzing the sub-flows comprises classifying the sub-flows into quality classes based on at least one data transmission quality-related factor of the sub-flows. Thereby transferring data between the first device and the second device.
The method of claim 3,
The process of analyzing the sub-flows may include calculating a loss rate of the sub-
And allocating the quality class to the sub-flow based on the calculated loss rate. The method of claim 1, wherein the quality class is allocated to the sub-flow.
10. The method of claim 9,
Calculating a loss rate of the sub-flow comprises:
Transmitting a plurality of data units using each sub-flow;
Recognizing the number of lost data units in a time window for each sub-flow;
And calculating an average loss rate within a time window for each sub-flow. ≪ Desc / Clms Page number 21 >
11. The method of claim 10,
Wherein the sub-flow having a calculated average loss rate less than a reference value is classified as a high quality class sub-flow.
The method of claim 3,
The process of analyzing the subflows comprises:
Calculating an expected transfer time to transfer a plurality of high priority level data units through a plurality of combinations of subgroups of the subflows;
Classifying the sub-flows of the sub-group having the lowest expected delivery time into a high-quality class.
13. The method of claim 12,
The process of calculating the expected delivery time comprises:
Attempting delivery of the plurality of data units through a subgroup of sub-flows;
And performing repetitive transmission of the plurality of data units to calculate the expected delivery time. ≪ Desc / Clms Page number 19 >
The method of claim 3,
Wherein the step of analyzing the sub-flows is performed dynamically in response to a condition of a network used for the MPTCP connection change. A method of transmitting data between a first device and a second device using an MPTCP connection .
The method according to claim 1,
Wherein the step of extracting the priority-related information comprises processing cross layer information. ≪ Desc / Clms Page number 19 >
16. The method of claim 15,
Wherein the intersection layer information includes information on data units crossing between a session layer and a transport layer, wherein the data between the first device and the second device using the MPTCP connection Lt; / RTI >
17. A method according to any one of claims 1 to 5 and 7 to 16,
Wherein the processing of the priority-related information comprises analyzing priority flags / signals of the data units. The method of claim 1, wherein the processing of the priority-related information comprises analyzing the priority flags / How to transfer.
17. A method according to any one of claims 1 to 5 and 7 to 16,
Wherein the step of processing the priority-related data comprises the step of analyzing a relevance order of the data units. The method of transmitting data between a first device and a second device using an MPTCP connection .
17. The method according to any one of claims 1 to 16,
The data unit may include a SPDY ™ message and the process of processing the priority-related data may include assigning a high priority level to a data unit including a SPDY ™ message having a SYN_STREAM or SYN_REPLY high priority identifier Wherein the MPTCP connection is used to transmit data between the first device and the second device.
17. The method according to any one of claims 1 to 16,
Wherein the data comprises video data, each data unit being categorized as an I-frame, a P-frame, or a B-frame, the processing of the priority- Assigning a higher priority level to the data unit including the P-frame or the B-frame, and assigning a lower priority level to the data unit including the P-frame or the B-frame. A method for transmitting data between two devices.
6. The method of claim 5,
The step of arranging the data units in the buffer includes forwarding data units having a high priority level to the buffer,
And backward loading data units having a lower priority level into the buffer. The method of claim 1, wherein the data is transmitted to the first device via the MPTCP connection.
22. The method of claim 21,
The step of arranging the data units in the buffer is to prevent further loading of data units having a low priority level into the buffer when the remaining space of the buffer is sufficient for loading data units having a high priority level Wherein the MPTCP connection is used to transmit data between the first device and the second device.
A system for transmitting data between a first device and a second device via a Multipath Transmission Control Protocol (MPTCP) connection, the system comprising:
A device configured to receive in-use data to be transmitted, the device comprising a collection of data units from the first device;
An analyzer configured to extract priority-related information for the data units from the received data;
A processing device configured to process the priority-related information to assign each of the data units to one of a plurality of sub-flows of the MPTCP connection;
And a data transfer device configured to transfer the in-use data units to the second device over the MPTCP connection using the assigned sub-flows. A system for transmitting data.
24. The method of claim 23,
Wherein the analyzer is logically located within an Android framework and the processing device is logically located within a Linux kernel and wherein data is transferred between the first device and the second device via an MPTCP connection, System.
25. The method according to claim 23 or 24,
Wherein the MPTCP connection uses at least one wireless network, and wherein data is transmitted between the first device and the second device through an MPTCP connection.
26. The method of claim 25,
Wherein the at least one wireless network comprises a 3G / LTE or Wi-Fi < (TM) > network.
A computer readable medium storing a computer program for operating a method according to any one of the preceding claims.

Images