JP2015228589A - Communications network - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communications network capable of achieving total optimization of power consumption and throughput.SOLUTION: The communications network includes: a plurality of communication apparatuses; and a controller. A plurality of communication lines exist between communication apparatuses. The communications network includes a cooperation control function for collecting information on the amount of communication for each session from communication apparatuses for each of the plurality of communication lines, determining capacities of a plurality of links to be used by respective communication apparatuses, and performing traffic control so as to be the determined values.

Description

  The present invention relates to a communication network, and more particularly to a technique for performing communication using a plurality of communication lines between communication devices.

  As an example of communication using a plurality of communication lines, a monitoring device collects congestion information of an access point, a base station, and a network (network), and an access point or a base to be connected to a terminal accommodated based on the congestion information A method for indicating a station has been proposed (see, for example, Patent Document 1). This method aims to smooth the load on the network and improve the quality of experience in application programs and the like used in each terminal.

  In addition, a smartphone or wireless LAN router that provides a tethering function instructs the terminal to accommodate it to use a specific fixed wireless LAN depending on the situation, reducing the power consumption of the smartphone or wireless LAN router. There is a technique (see, for example, Patent Document 2).

  These techniques described in Patent Documents 1 and 2 are techniques for selecting any one of a plurality of communication lines.

  In addition, there is a communication technology defined as RFC 6824: TCP Extensions for Multiple Operation with Multiple Addresses by IETF (Internet Engineering Task Force) which is an organization that promotes standardization. This communication technique is called MPTCP, and is a technique for performing one TCP session using a plurality of communication lines and interfaces when communicating between terminals or between a terminal and a server using the Internet. MPTCP speeds up communication compared to conventional TCP, and improves reliability in unstable transmission media such as wireless communication.

  Normal TCP has means for realizing one TCP function (hereinafter referred to as TCP means) on the transmission side and reception side of the communication line. In contrast, MPTCP includes TCP means (also referred to as inner TCP means) at both ends of a plurality of communication lines, and also includes TCP means (also referred to as outer TCP means) connected to the plurality of TCP means. Yes. In this MPTCP, the inner TCP means provides highly reliable communication in each of the plurality of communication lines, and the outer TCP means performs communication by distributing packets to the plurality of communication lines.

For example, the following four methods have been proposed as a method by which the outer TCP means distributes packets (see, for example, Non-Patent Document 1).
(1) A round robin method in which a plurality of communication lines are used equally one after another. (2) A packet is distributed to a communication line having the smallest delay time (RTT), and priority is given to reducing arrival order inversion. LINUX (registered trademark) kernel implementation method (3) ATLB method that further reduces arrival order reversal by adding the value obtained by dividing the traffic accumulated in the transmission queue by the throughput to the RTT and obtaining the expected time to exit the transmission queue (4) In the ATLB system, in order to improve the accuracy of the expected time to exit the transmission queue, not only the traffic is divided by the throughput, but also the Oikawa's proposed system that considers which phase of TCP

JP 2013-179492 A JP 2013-219740 A

Oikawa Nagatoshi, Nakagawa Yasushi “Proposal of Multipath TCP Packet Distribution Method in Network with Large Delay Difference” IEICE Technical Report NS2012-106

  However, the techniques disclosed in Patent Documents 1 and 2 described above are techniques that selectively use any one of a plurality of communication lines, and cannot be used when a plurality of communication lines are used simultaneously. In addition, the above-described Patent Documents 1 and 2 and Non-Patent Document 1 are techniques in which each terminal operates individually. For this reason, there is a possibility that the overall optimization may not be achieved in terms of power consumption including the station side equipment and throughput of the entire network.

  The present invention has been made in view of the above-described problems, and an object of the present invention is a communication network in which a plurality of communication lines exist between terminals, and can achieve overall optimization of power consumption and throughput. To provide a communication network.

  In order to achieve the above-described object, the communication network of the present invention is a communication network that includes a plurality of communication devices and a controller, and in which a plurality of communication lines exist between the communication devices. The transmission-side communication apparatus includes a plurality of packet transfer means provided for each of a plurality of communication lines for transferring packets, and a packet distribution means for distributing packets to the plurality of packet transfer means. The communication device on the receiving side confirms delivery of the received packet and requests retransmission of the packet to the packet transfer means upon non-delivery. The plurality of packet receiving means provided for each of the plurality of communication lines and the plurality of packet receiving means receive Packet aligning means for aligning the received packets. The controller collects communication volume information for each session from the communication device for each of the plurality of communication lines, determines the capacity of a plurality of links to be used by each communication device, and controls the traffic so that the determined value is obtained. It has a cooperation control function to perform.

  According to the communication network of the present invention, the cooperation control function of the controller collects information on the communication amount for each session from the communication device for each of the plurality of communication lines, and the plurality of links to be used by each communication device. Since the capacity is determined and the traffic control is performed so that the determined value is obtained, overall optimization can be realized with respect to power consumption and throughput.

It is a schematic diagram for demonstrating the structural example of a communication network. It is a schematic diagram which shows MPTCP.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the arrangement relationship of each component is merely schematically shown to the extent that the present invention can be understood. In the following, a preferred configuration example of the present invention will be described. However, numerical conditions and the like are merely preferred examples. Therefore, the present invention is not limited to the following embodiments, and many modifications can be made without departing from the scope of the configuration of the present invention.

  A configuration example of a communication network will be described with reference to FIG. FIG. 1 is a schematic diagram for explaining a configuration example of a communication network. Here, an example in which four systems of WiFi, WiMax, LTE, and 3G are used as communication lines will be described.

  This communication network includes a fronthaul network, a backhaul network, a network OpS (Operating System), a controller, the Internet, and a server.

  In the fronthaul network, an access point, a base station, or a repeater (trapon) is provided as a node to which a plurality of terminals and each terminal can be connected. A plurality of terminals and these nodes communicate with each other through any one of four systems: WiFi, WiMax, LTE, and 3G.

  The backhaul network includes an access network including an OLT-ONU transmission line, a trapon-trapon transmission line, a core network, and a WiFi, WiMax, and LTE / 3G backhaul. Each backhaul connects the node to a server in the data center and the Internet. The node may be connected to the server via the Internet. In the configuration example of FIG. 1, the WiFi backhaul connects a WiFi base station as a node to the server A and the Internet. In FIG. 1, the base station or the like is provided in the fronthaul network, but the portion on the backhaul side from the base station or the like belongs to the backhaul network.

  The network OpS includes the OpS of each communication line, and manages and operates the communication line.

  WiFiOpS manages and operates communication lines related to WiFi in the backhaul network.

  A WiFi provider installs a WiFi base station. A part of the access network is borrowed from the access network operator as a virtual access network and used as a part of the WiFi backhaul. The WiFi backhaul has an AAA (Authentication, Authorization, Accounting) function for authenticating, authorizing, and charging a terminal, and a resource allocation function for allocating communication resources (communication lines). These functions are managed and operated by WiFiOpS. The WiFi provider borrows a part of the core network from the core network provider as a virtual core network and uses it as a part of the WiFi backhaul or connects to a server. Also, the WiFi provider may provide a part of the WiFi backhaul as a virtual WiFi backhaul that other operators can operate independently.

  Since WiMax is configured in the same manner as WiFi, description thereof is omitted here. The WiMax backhaul may also be provided to other operators as a virtual WiMax backhaul that can operate a part of the WiMax backhaul independently as in the case of WiFi.

  LTE and 3G are provided by the same mobile operator.

  In the 3G service, a transmission path including ONU-OLT, which is an equipment of an access network operator, is borrowed from a 3G base station as a virtual access network. This virtual access network is directly connected to a server or other communication core network via SGSN (Serving General Packet Radio Service Support Node), S-GW (Serving Gateway), P-GW (Packet Data Network Gateway) Connected with.

  LTE virtually transmits a transmission path including an antenna, an ONU-OLT that is an equipment of an access network operator, from a base station indicated by eNb in the figure, which is composed of an RRH (Remote Radio Head) and a BBU (Base Band Unit). Borrowed as an access network. An LTE base station is connected to a server or another communication line directly or via a virtual core network via MME (Mobility Management Entity), S-GW, or P-GW.

  PCRF (Policy and Charge Rules Function) manages resource allocation and policy in LTE / 3G backhaul, and is managed and operated by mobile OpS including HSS (Home Subscriber Server) which is a database.

  Terminals and servers include application software for providing or enjoying communication services and network grasping / control functions, including functions for monitoring communication status and arbitrarily determining the proportion of resources to be used. It is. Note that some or all of the network grasping / control functions may not be included in the terminal or server.

  The controller includes a linkage control function. This cooperation control function can issue instructions to some or all of the WiFi, WiMax, LTE, 3G, OpS of the core network and the access network, and the network grasping / control function of the terminal and the server.

(Operation)
A case where the mobile operator optimizes the communication of the terminal will be described. The mobile operator has an LTE / 3G backhaul, an LTE / 3G base station and a mobile OpS. Then, the mobile operator borrows WiMax or WiFi base stations, traps, backhauls, access networks, and core networks from each operator and virtually uses them as their own networks.

(First embodiment)
With reference to FIG. 2, the operation of the first embodiment when the terminal can measure and control the state of the network will be described. FIG. 2 is a schematic diagram showing MPTCP. MPTCP includes TCP means (also referred to as inner TCP means) at both ends of a plurality of communication lines, and also includes TCP means (also referred to as outer TCP means) connected to the plurality of TCP means. In this MPTCP, the inner TCP means provides highly reliable communication in each of the plurality of communication lines, and the outer TCP means performs communication by distributing packets to the plurality of communication lines. More specifically, the packet distribution unit that is the outer TCP unit of the transmission side communication device distributes the packet to the plurality of inner TCP units. Packet transfer means, which is an inner TCP means of the communication device on the transmission side, is provided for each of a plurality of communication lines and transfers packets. The packet receiving means, which is the inner TCP means of the receiving side communication device, is provided for each of the plurality of communication lines, and makes a packet retransmission request to the packet transfer means upon confirmation of delivery of the received packet and non-delivery. The packet aligning means, which is the outer TCP means of the receiving side communication device, aligns the packets received by the plurality of packet receiving means.

  In the first embodiment, the terminal has means for measuring power consumption, and notifies the controller of this power consumption. Further, the terminal measures the delay time and available bandwidth when transmitting to the server for each communication line, and sends the information to the cooperation control function of the controller. The cooperation control function performs optimal resource allocation based on information collected from each terminal and notifies the result to each terminal. Each terminal performs bandwidth control of each communication line based on the resource allocation result sent from the cooperation control function. In this case, one TCP session may be divided and communicated over a plurality of communication lines. The resource allocation performed by the cooperation control function will be described later.

  The upstream signal from the terminal to the server is distributed to each of a plurality of lines by the outer TCP means in response to an instruction from the cooperation control function in the terminal on the transmission side. On the other hand, the bandwidth of the downlink signal from the server to the terminal can be controlled by controlling the transmission timing of the reception acknowledgment (ACK) in the terminal on the receiving side.

  Here, the case where the terminal can measure and control the state of the network in communication between the terminal and the server has been described, but the server may measure and control the state of the network. .

  In this case, the server measures the delay time and available bandwidth when transmitting to the terminal for each communication line, and sends the information to the cooperation control function of the controller. The cooperation control function performs optimal resource allocation based on information collected from the server, and notifies the server of the result. The server performs bandwidth control of each communication line based on the resource allocation result sent from the cooperation control function.

  The downstream signal from the server to the terminal is distributed to each of a plurality of lines by the outer TCP unit in response to an instruction from the cooperation control function in the server which is a communication device on the transmission side. On the other hand, the bandwidth of the uplink signal from the terminal to the server can be controlled by controlling the transmission timing of ACK in the server which is the communication device on the receiving side.

  The traffic [bit / sec] for each communication resource is given by, for example, transmission window size [Byte] × 8 / round trip delay time [sec]. The power consumption information can also be estimated from the received power of the communication interface of the terminal body and the round trip delay time. This estimated power consumption information is notified to the controller.

  Further, when the terminal can measure or control the state of the network, this control can also be performed by communication between the terminal and the terminal. In this case, for the transmission from the first terminal to the second terminal, the first terminal performs packet distribution, and for the communication from the second terminal to the first terminal, the second terminal It may be configured to distribute packets.

(Second embodiment)
Next, a case where measurement / control is impossible in a terminal or server will be described. In this case, information on which traffic of which terminal is flowing through which communication line is necessary. This information can be known by using charging information measured by the AAA function in each backhaul by one or more nodes provided between the communication devices. Further, the power consumption can be estimated from the radio wave intensity and error rate at the base station based on the transmission intensity of the terminal. Information such as billing information, radio wave intensity, and error rate is sent to the cooperation control function of the controller. The cooperation control function calculates an optimum resource allocation based on the received information, and realizes a desired operation by controlling the backhaul bandwidth allocation function and the PCRF function according to the result. The traffic may be controlled by transmitting a Pause frame from the node facing the transmitting terminal to the transmitting terminal so as to suppress transmission from the transmitting terminal to the line.

(Optimization method for the entire system)
A method for optimizing the entire system will be described. Here, three terminals, terminals 1, 2 and 3, use four communication lines, communication line 1 (WiMax), communication line 2 (WiFi), communication line 3 (LTE), and communication line 4 (3G). A case will be described as an example. Note that numbers such as the number of terminals, power consumption, and bandwidth are merely examples.

  Table 1 shows transmission resources (unit: Mb / s) required for each of the terminals 1, 2, and 3, the respective bands (unit: Mb / s) of WiMax, WiFi, LTE, and 3G, and the terminals. Power consumption (unit: μWh). The power consumption of each terminal differs depending on the line because, for example, the radio wave intensity to be output differs depending on the distance between the base station and the terminal and the presence or absence of an obstacle. Further, the plurality of resources do not necessarily need to be a plurality of wireless communication schemes, and may be, for example, two communication units, WiFi1 and WiFi2.

  Table 2 shows an example in which each terminal uses resources with less power consumption in order, without performing optimization in the entire system. As shown in Table 1, each terminal consumes the least power when using the communication line 2 (WiFi). Therefore, the WiFi bandwidth of 6 Mb / s is used equally by 3 terminals at 2 Mb / s. Next, since the resource with low power consumption is the communication line 1 (WiMax), the WiMax bandwidth 3 Mb / s is used equally by the three terminals at 1 Mb / s. Next, since the resource with low power consumption is the communication line 3 (LTE), the LTE band 3 Mb / s is equally used by the three terminals 1 Mb / s at a time. As a result, since all the transmission resources 4Mb / s necessary for each terminal are allocated to the communication lines 1 to 3, the communication line 4 (3G) having the largest power consumption is not used.

  In this case, the total power consumption of each terminal is 39 μWh for terminal 1, 25 μWh for terminal 2, and 27 μWh for terminal 3, so that the power consumption of the entire system is 91 μWh.

  Table 3 shows a resource allocation method that minimizes power consumption in the entire system. Here, the communication line 2 is preferentially allocated to the terminal 2 and the terminal 3 with low power consumption for the communication line 2, and the terminals 2 and 3 use 3 Mb / s each. Thereafter, the communication line 1 is equally assigned to the three terminals by 1 Mb / s, and the remaining 3 Mb / s for the terminal 1 is assigned to the communication line 3. In this case, the communication line 1 is 43 μWh, and the power consumption is larger than that in Table 2. However, since the terminal 2 is 16 μWh and the terminal 3 is 19 μWh, the power consumption of the entire system is 78 μWh, and power saving can be achieved as compared with Table 2.

  Table 4 shows a resource allocation method for minimizing the power consumption of the terminal having the maximum power consumption. Here, the communication line 2 is preferentially assigned to the terminal 1, the terminal 1 uses 4 Mb / s, and the terminals 2 and 3 use 1 Mb / s. The terminal 2 uses 1 Mb / s and the terminal 3 uses 2 Mb / s of the communication line 1. Further, the terminal 2 uses 2 Mb / s and the terminal 3 uses 1 Mb / s for the communication line 3. In this case, since the terminal 1 is 36 μWh, the terminal 2 is 34 μWh, and the terminal 3 is 34 μWh, the power consumption of the entire system is 104 μWh, which is larger than those in Tables 2 and 3. However, the power consumption of the terminal 1 which is the terminal with the largest power consumption is 36 μWh, and the power consumption of the terminal with the largest power consumption is the smallest. This is the control for delaying the time when the terminal that runs out of battery earliest occurs. Further, the difference in power consumption between the terminals 1 to 3 is 2 μWh at the maximum, which is smaller than Tables 2 and 3 which are 14 μWh and 27 μWh, respectively, and can improve fairness from the viewpoint of power consumption.

  According to the present invention, each terminal uses resources (communication lines) with low power consumption preferentially as fairly as possible, minimizes the overall power consumption, minimizes the difference in total power consumption of each terminal, When at least one of the terminals is operated by a battery, a terminal with a low remaining battery level preferentially uses a resource with low power consumption, and minimizes the difference in power consumption for a predetermined period for each communication device Can be controlled according to the schedule and network policy, and as a result, overall optimization can be realized.

Claims (6)

A communication network including a plurality of communication devices and a controller, and having a plurality of communication lines between the communication devices,
The communication device on the sending side
A plurality of packet transfer means provided for each of the plurality of communication lines for transferring packets;
Packet distribution means for distributing packets to the plurality of packet transfer means,
The communication device on the receiving side
A plurality of packet receiving means provided for each of the plurality of communication lines, which performs a packet retransmission request to the packet transfer means upon receipt confirmation and non-delivery of the received packet;
Packet alignment means for aligning packets received by the plurality of packet receiving means,
The controller is
Collecting information on the traffic for each session from the communication device for each of the plurality of communication lines,
Determine the capacity of multiple links that each communication device should use,
A communication network having a cooperative control function for performing traffic control so that the determined value is obtained. The distribution of packets by the traffic control is as follows:
Distribution that preferentially uses communication lines with low power consumption,
Distribution that minimizes overall power consumption,
When at least one of the communication devices is operated by a battery, a communication device with a low remaining battery capacity is preferentially using a communication line with low power consumption, and communication of power consumption for a predetermined period. The communication network according to claim 1, wherein the communication network is one of distributions that minimizes a difference between devices. The communication device is
Means for measuring power consumption, or means for predicting power consumption from transmission strength, error rate, and traffic;
The communication network according to claim 2, further comprising means for notifying the controller of the power consumption. One or more nodes are provided between the communication devices,
The communication node according to claim 2, wherein the node has a function of predicting power consumption from transmission intensity, error rate, and traffic. The traffic control is
Performed in response to an instruction from the controller,
Control for packet distribution by the packet distribution means of the communication device on the transmission side,
Control for adjusting the timing of delivery confirmation sent by the packet receiving means of the communication device on the reception side to the communication device on the transmission side;
The communication network according to claim 1, wherein the communication network is any one of the above. One or more nodes are provided between the communication devices,
The traffic control is
Control by which the node coordinates traffic according to a schedule or network policy;
5. The control device according to claim 1, wherein a node facing the communication device on the transmission side among the nodes is any one of the controls for sending a Pause frame to the communication device on the transmission side. The communication network described in 1.

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