WO2011135794A1 - Communication method, communication system, communication device, and management node - Google Patents

Abstract

When transmitting data from a plurality of communication devices to a data collection server via a wireless network and communicating data between the respective communication devices via the wireless network, congestion and a packet loss are reduced. By the configuration, when transmitting data from MTC devices (1A, 1B) to an MTC server (2) and communicating data between the MTC devices (1A) and (1B), an MME (5) which manages the MTC devices (1A, 1B) and the MTC server (2) allocates a first access time interval (TP1) for transmitting each data from the MTC devices (1A, 1B) to the MTC server (2) and a second access time interval (TP2) for transmitting and receiving each data between the MTC devices (1A) and (1B).

Description

Communication method, communication system, communication device, and management node

The present invention relates to a communication method, a communication system, a communication device, and a management node for transmitting data from a plurality of communication devices to a data collection server via a wireless network and communicating data between the communication devices.

Unlike communication (Human to Human (H2H), Human to Machine (H2M)), which uses a terminal equipped with a rich user interface such as a mobile phone, direct operation by the user is required. As a form of communication using a device that can operate independently (hereinafter referred to as MTC (Machine Type Communication) device), there is an inter-machine communication (called Machine Type to Machine Type Communication or Machine Type Type Communication, hereinafter referred to as M2M communication). . In M2M communication, one or more devices (hereinafter referred to as MTC devices) that are located at the end and appropriately collect necessary information operate, and are detected by sensing functions (for example, temperature, seismic intensity, and water volume) that each MTC device has. The measured information is collected in a server (hereinafter referred to as an MTC server) that manages the MTC device, and various services are provided to users (clients) based on the information. The user is provided with a service based on information notified from the MTC device via the MTC server.

As means for establishing a communication path between the MTC device and the MTC server, not only a wired network such as a telephone line or a DSL (Digital Subscriber Line) line but also a wireless network such as a cellular phone network can be used. . In particular, when wireless is used, restrictions on the installation location of the MTC device are almost eliminated, so that it is possible to install the MTC device in a wide range, and it can be said that this is a very effective communication means.

However, a wireless communication system usually used for a mobile phone or the like is optimized for a mobile phone and is not necessarily optimal for an MTC device that provides a service specialized for M2M communication. For example, in the case of a mobile phone, it is necessary to periodically check paging from the network side in order to receive an incoming voice call addressed to itself. However, if the MTC device does not have a voice call function, the paging is always performed. Since it is not necessary to be able to receive, such an operation becomes unnecessary.

In addition, since MTC devices have a wide range of installation locations and few contact with the user, there is little possibility of being placed in a state where power is always supplied. Therefore, since it is necessary to use limited electric power such as a battery or a battery, it is required to suppress power consumption as much as possible and lengthen the operation time. In particular, power consumed by a radio interface used for communication cannot be ignored, and optimizing a radio communication system for an MTC device is an indispensable problem for an MTC device using radio communication. Currently, 3GPP (3rd Generation Partnership Project) discusses optimization of the mobile phone network for M2M communication (see Non-Patent Document 1 below and Non-Patent Document 2 below).

Furthermore, it is expected that the larger the installation scale, the greater the number of MTC devices that operate. For this reason, when a large number of MTC devices are simultaneously connected to the network and data transmission / reception is started, it is expected that congestion will occur in the wireless network and the core network. For this reason, a mechanism to minimize access concentration is also necessary.

In this way, considering the reduction of power consumption, it is not realistic that the MTC device is always connected to the network and the connection with the server is ensured, so that it can be connected to the network only when necessary when necessary. It is appropriate to do. As a method for that purpose, a method (Time Control) is conceived in which a time interval for the MTC device to access the network is specified in advance, and access is controlled within the time interval. In addition, when the same time interval is specified for a plurality of MTC devices, it is also necessary to avoid congestion that occurs when a plurality of MTC devices access the network at the same time.

In the currently considered method, the MTC device receives a notification of a time interval during which access is permitted from the network or the MTC server, and connects to the network at an arbitrary timing within the specified time. Since the access timing is randomly determined by each MTC device, even when the same time interval is notified to a plurality of MTC devices, the access timing is distributed so that access is not concentrated. Yes. By this method, the network only specifies a common time interval for a plurality of MTC devices (for example, MTC devices belonging to the same group), and limits the time for the MTC devices to access the network. In addition, since the access timing is determined by the determination of each MTC device, the management cost on the network side can be reduced.

When all MTC devices communicate with only one MTC server, there is always only one communication partner for the MTC device, and one connection is sufficient, so the bandwidth and management costs used are minimal. It's all you need However, if one MTC device can communicate with another MTC device or another MTC server, it transmits data to another communication partner simultaneously with data transmission to the MTC server. Therefore, the bandwidth to be used and the processing cost of the MTC device also increase. For the MTC device, data transmission to the MTC server is one of basic operations, and is an important operation for fulfilling the function as the MTC device. For this reason, when the same time interval is allocated to each MTC device, there is a high possibility of receiving a request from another MTC device during data transmission to the MTC server.

However, an MTC device that has received a request from another MTC device needs to transmit data to both the MTC server and the requesting MTC device at the same time. The network is congested by the data that is generated. FIG. 19 is a sequence chart for explaining the problem to be solved by the present invention. In (1), the MTC devices 1A and 1B belong to the same group and are assigned the same access time interval P1. Referring to FIG. 19, (2) when the MTC device 1A communicates with the MTC server 2 at the data transmission interval P11 within the access time interval P1, (3) receives a data request from the MTC device 1B. (4) When data is transmitted to the MTC device B at the data transmission interval P12 within the access time interval P1, the interval P13 at which data transmission to the MTC server 2 and data transmission to the MTC device 1B are performed simultaneously is performed. Arise. As a result, there is a problem in that transmission data is delayed and packet loss occurs when the available bandwidth is exceeded.

In view of the above problems, the present invention reduces congestion and packet loss when data is transmitted from a plurality of communication devices to a data collection server via a wireless network and data is communicated between the communication devices. An object of the present invention is to provide a communication method, a communication system, a communication device, and a management node.

In order to achieve the above object, the present invention is a communication method for transmitting data from a plurality of communication devices to a data collection server via a wireless network and communicating data between the communication devices,
A first access time interval for transmitting each data from the plurality of communication devices to the data collection server from a management node that manages the plurality of communication devices to the plurality of communication devices, and the plurality of communication Assigning a second access time interval for transmitting and receiving each piece of data between devices;
The plurality of communication devices transmitting each piece of data to the data collection server in the assigned first access time interval;
Transmitting and receiving data between the plurality of communication devices in the allocated second access time interval; and
It was set as the structure which has.

In order to achieve the above object, the present invention is a communication system for transmitting data from a plurality of communication devices to a data collection server via a wireless network and communicating data between the communication devices,
A first access time interval for transmitting each data from the plurality of communication devices to the data collection server from a management node that manages the plurality of communication devices to the plurality of communication devices, and the plurality of communication Allocating means for allocating a second access time interval for transmitting and receiving each data between devices;
Means for the plurality of communication devices to transmit each data to the data collection server in the assigned first access time interval;
Means for transmitting and receiving data between the plurality of communication devices in the allocated second access time interval;
It was set as the structure which has.

In order to achieve the above object, the present invention provides a communication device in a communication system for transmitting data from a plurality of communication devices to a data collection server via a wireless network and communicating data between the communication devices. There,
A first access time interval for transmitting each data from the plurality of communication devices to the data collection server from a management node that manages the plurality of communication devices to the plurality of communication devices, and the plurality of communication Means for accepting assignment when a second access time interval for transmitting and receiving data between devices is assigned;
Means for transmitting each data to the data collection server in the assigned first access time interval;
Means for transmitting and receiving data between the other communication devices in the allocated second access time interval;
It was set as the structure which has.

In order to achieve the above object, the present invention provides a communication system in which data is transmitted from a plurality of communication devices to a data collection server via a wireless network and data is communicated between the communication devices. A management node that manages the device,
A first access time interval for transmitting each piece of data from the plurality of communication devices to the data collection server and a first number for transmitting / receiving each piece of data between the plurality of communication devices to the plurality of communication devices. Assigning means for assigning two access time intervals,
It was set as the structure which has.

With this configuration, for the plurality of communication devices, the first access time interval for transmitting each data from the plurality of communication devices to the data collection server and the first access time for transmitting / receiving each data between the plurality of communication devices. Since two access time intervals are allocated, when data is transmitted from a plurality of communication devices to the data collection server via the wireless network and data is communicated between the communication devices, congestion and packet loss are reduced. be able to.

According to the present invention, when data is transmitted from a plurality of communication devices to a data collection server via a wireless network and data is communicated between the communication devices, congestion and packet loss can be reduced. .

The block diagram which shows an example of the network structure in the 1st Embodiment of this invention Explanatory drawing which shows the communication sequence in the 1st Embodiment of this invention Explanatory drawing which shows the modification of the communication sequence of FIG. Explanatory drawing which shows the allocation sequence of the time interval of FIG.2 and FIG.3 in detail Explanatory drawing which shows the modification of the allocation sequence of FIG. The block diagram which shows in detail the structure of the data transmission source MTC device in FIG. Explanatory drawing which shows the modification of the communication sequence of FIG. The block diagram which shows the structure of the data request origin MTC device in FIG. 1 in detail The block diagram which shows the structure of MME in FIG. 1 in detail Explanatory drawing which shows the communication sequence in the 2nd Embodiment of this invention. The flowchart for demonstrating the request processing of the data transmission origin MTC device in the 2nd Embodiment of this invention The flowchart for demonstrating the data transmission process of the data transmission origin MTC device in the 2nd Embodiment of this invention Explanatory drawing which shows the communication sequence in the 3rd Embodiment of this invention. Timing chart for explaining the processing of the data transmission source MTC device in the third embodiment of the present invention The block diagram which shows in detail the structure of the data request origin MTC device in the 3rd Embodiment of this invention Explanatory drawing which shows the modification of the communication sequence in the 3rd Embodiment of this invention. The flowchart for demonstrating the data transmission process of the data transmission origin MTC device in the 3rd Embodiment of this invention Explanatory drawing which shows the modification of the communication sequence in the 3rd Embodiment of this invention. Sequence chart for explaining problems to be solved by the present invention

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
FIG. 1 is a diagram illustrating an example of a network configuration according to the first embodiment of this invention. Consider a case where the MTC device 1A and the MTC device 1B are operating as a plurality of MTC devices. These MTC devices 1A and 1B have a 3GPP interface as a radio access module, and can be connected to a network (for example, 3GPP core network) 4 via a base station (eNB: evolved Node B) 3, for example. . The network 4 includes an MME (Mobility Management Entity) 5, an S-GW (Serving Gateway) 6, and a P-GW (Packet Data Gateway) 7 that manage the MTC devices 1A and 1B and the MTC server 2. The entities 5, 6, and 7 manage the connection state of the MTC devices 1A and 1B, establish and manage connections necessary for the MTC devices 1A and 1B to access the MTC server 2, and transfer data. The MTC server 2 is a server that manages the MTC devices 1A and 1B, and provides services to the user U based on various information notified from the MTC devices 1A and 1B. The MTC device 1A and the MTC device 1B generate a connection with the MTC server 2 via the 3GPP core network 4, and notify the MTC server 2 of collected data and events. In the present embodiment, it is assumed that the MTC server 2 and the MTC device 1B require the data held by the MTC device 1A. However, both of the MTC devices (the MTC device 1B and other MTC devices ( (Not shown)) may be requested to transmit data.

In addition, as a radio | wireless access module which MTC device 1A, 1B hold | maintains, other radio | wireless systems, such as WiMAX (trademark) and WLAN, may be used, and it is not limited to a 3GPP interface. In addition, the entities 5, 6, and 7 in the core network 4 shown in FIG. 1 represent functional blocks in the case of using 3GPP LTE / SAE (Long Term Term Evolution / System Architecture) Evolution as a radio access system. However, depending on the radio access system to be used, it is replaced with an appropriate entity name having the same function. For example, when 3GPP UMTS (Universal Mobile Telecommunication System) is used, eNB 3 is RNC / BSC (Radio Network Controller / Base Station Controller), MME 5 is SGSN (Serving GPRS Support Node), and P-GW 7 is GGSN (Gateway GPRS). Support Node). Further, the MTC server 2 may be disposed in the 3GPP core network 4.

FIG. 2 is a sequence chart illustrating an example of processing when communication is performed among the MTC device 1A, the MTC server 2, and the MTC device 1B. First,
(1) The MTC device 1A and the MTC device 1B are assigned two access time intervals from the network 4 side. One is an access time interval TP1 indicating a time during which communication with the MTC server 2 is permitted, and the other is an access time interval TP2 indicating a time during which communication between the MTC devices 1A-1B is permitted. The notification method of the access time intervals TP1 and TP2 is not limited to the dynamic notification method to be described later, and the operator or the MTC server 2 and the MTC user U specify the MTC devices 1A and 1B that perform communication between MTC devices, The access time intervals TP1 and TP2 may be assigned in advance. In this case, it may be stored in advance in the subscription data of each MTC device 1A, 1B, or may be notified when each MTC device 1A, 1B is connected to the network 4. The MTC device 1A and the MTC device 1B that have been assigned the access time intervals TP1 and TP2 can recognize that they can communicate with other MTC devices in the access time interval TP2.

(2) When there is data to be notified to the MTC server 2, the MTC device 1A that has received the notification of these access time intervals TP1 and TP2 has a start time indicated by the access time interval TP1 to the MTC server 2. Then, transmission of data to the MTC server 2 is started at an arbitrary timing within the access time interval TP1 (data transmission interval TP11 ≦ TP1). Although not shown in (2), the MTC device 1B also similarly has an access time interval TP1 when there is data to be notified to the MTC server 2 when the start time indicated by the access time interval TP1 is reached. Transmission of data to the MTC server 2 is started at an arbitrary timing.
(3) On the other hand, when there is data to be acquired from the MTC device 1A, the MTC device 1B makes a data request to the MTC device 1A at an arbitrary timing after the start time indicated by the access time interval TP2 between the MTC devices. Send.
(4) When the MTC device 1A receives a data transmission request from the MTC device 1B, if the received timing is within the access time interval TP2, the MTC device 1A accepts the request and receives necessary data. Is started (data transmission interval TP21 ≦ TP2). On the other hand, when the timing at which the request from the MTC device 1B is received is within the range of the access time interval TP1 to the MTC server 2, the request is rejected and data is not transmitted.

In addition, when the MTC device 1A transmits data in response to a request from the MTC server 2, the MTC device 1A starts data transmission when the timing at which the request from the MTC server 2 is received is within the access time interval TP1. However, data transmission is not performed when it is within the range of the access time interval TP2. Even when the timing of receiving the request is the access time interval TP2, the request may be set to be accepted if the request is from the MTC server 2. That is, TP1 and TP2 are effective access time intervals for communication with the server 2, and TP2 is set as an effective access time interval for communication between the MTC devices 1A-1B.

As described above, when the MTC device 1A communicates not only with the MTC server 2, but also with another MTC device 1B, an access time interval TP1 that permits communication between the MTC devices 1A, 1B and the MTC server 2 and the MTC device 1A By separately assigning the access time interval TP2 that permits communication between -1B, it is possible to prevent the data transmission to the MTC server 2 and the data transmission to the MTC devices 1A and 1B from being performed simultaneously. Note that the MTC devices 1A and 1B may not be connected to the network 4 after acquiring the access time intervals TP1 and TP2 until an arbitrary time within the designated access time intervals TP1 and TP2. That is, the MTC device 1A does not need to be connected to the network 4 until data transmission to the MTC server 2 is performed. Further, the MTC device 1B does not need to be connected to the network 4 until a data request is transmitted to the MTC device 1A.

In FIG. 2, the access time interval TP2 assigned to communication with other MTC devices is arranged after the access time interval TP1 assigned to communication with the MTC server 2, but instead, FIG. As shown in FIG. 5, the access time interval TP2 may be arranged before the access time interval TP1. In this case, since the MTC device 1B can transmit data to the MTC server 2 after acquiring information from the MTC device 1A, the MTC device 1B notifies the MTC server 2 of data considering the information acquired from the MTC device 1A. be able to. When the MTC device 1B transmits to the MTC server 2 including the data acquired from the MTC device 1A, the MTC device 1A determines that the data transmitted to the MTC device 1B does not need to be transmitted to the MTC server 2. May be. Thereby, the traffic and load which generate | occur | produce when MTC device A transmits data to the MTC server 2 can be reduced.

FIG. 4 is an example of a sequence chart showing how access time intervals TP1 and TP2 are dynamically allocated to the MTC device 1A and the MTC device 1B. (1) In assigning time intervals,
(11) When the MTC device 1B wants to communicate with the MTC device 1A, the MTC device 1B first transmits to the MME 5 (or the MTC server 2) an MTC device communication request indicating that communication with the MTC device 1A is performed.
(12) (13) When the MME 5 receives the communication request between the MTC devices, the MME 5 prevents the access to the MTC device 1A by the MTC device 1B from affecting the communication with the MTC server 2 by the MTC device 1A. The access time intervals TP1 and TP2 are both assigned to the MTC device 1B and the MTC device 1A.

Here, it is assumed that the MTC device 1A and the MTC device 1B are managed by the same MME 5, but if the MTC devices 1A and 1B are managed by different MMEs, the MTC device 1B to the MTC device Access time intervals TP1 and TP2 are determined by exchanging messages between the MME that has received the inter-communication request and the MME that manages the MTC device 1A. Further, when the MTC server 2 holds the function of the MME 5 in the first embodiment of the present invention, the MTC device 1B transmits an inter-MTC device communication request to the MTC server 2. In this case, the MTC server 2 determines appropriate access time intervals TP1 and TP2 and assigns them to the respective MTC devices 1A and 1B. When each MTC device 1A, 1B is managed by a different MTC server, between the MTC server that has received the MTC device communication request from the MTC device 1B and the MTC server that manages the MTC device 1A. Access time intervals TP1 and TP2 are determined by exchanging messages.

The MTC device A and the MTC device B that have received notification of these access time intervals TP1 and TP2 recognize that communication between devices is possible in the access time interval TP2. It is desirable that the MTC device 1A obtains information (ID or IP address of the MTC device 1B) indicating the communication partner to which access is permitted (communication partner who has requested access) together with the access time intervals TP1 and TP2. As a result, the MTC device 1A can recognize that an access request comes from the MTC device 1B within the access time interval TP2, and at the same time, can reject an access request from an MTC device other than the MTC device 1B. After receiving the notification of the access time intervals TP1 and TP2 based on FIG. 4, each of the MTC devices 1A and 1B transmits and receives data as shown in the processes (2), (3), and (4) described with reference to FIG. Do.

In (1) time interval allocation, as shown in FIGS. 5 (11), (12), and (13), the MTC device communication request indicating that the MTC device 1A communicates with the MTC device 1B instead. May be sent. In this case, when it is determined that there is data to be transmitted to the MTC device 1B, the MTC device 1A transmits a communication request between MTC devices. As a result, the access time interval TP2 for inter-device communication can be assigned only when the MTC device 1A that actually transmits data determines that inter-device communication is necessary. It is desirable that the MTC device 1B obtains information (ID and IP address of the MTC device 1A) indicating the communication partner permitted to access, together with the access time intervals TP1 and TP2. As a result, the MTC device 1B can recognize that it can access the MTC device 1A within the access time interval TP2, and at the same time, rejects an access request from an MTC device other than the MTC device 1A. can do. After receiving the notification of the access time intervals TP1 and TP2 based on FIG. 5, each of the MTC devices 1A and 1B transmits and receives data as shown in the processes (2), (3), and (4) described with reference to FIG. Do.

When it is desired to receive the allocation of the access time intervals TP2 and TP1 in the order (TP2 → TP1) as shown in FIG. 3, the MTC device 1B in FIG. 4 and the MTC device 1A in FIG. May include explicit information (for example, a flag) requesting that the access time interval TP2 be allocated before the access time interval TP1. Further, instead of including explicit information, the MME 5 that has received the communication request between MTC devices transmits the communication request between the MTC devices 1B or 1A from other MTC devices in order to generate its own transmission data. When it is determined that the information is an MTC device that requires this information, the access time interval TP2 may be assigned before the access time interval TP1.

In addition, the MTC device 1B in FIG. 4 and the MTC device 1A in FIG. 5 do not include the ID of the MTC device that is the communication partner in the communication request between MTC devices, but the MME 5 that has received the communication request between MTC devices is appropriate communication. You may select a partner. In this case, information (MTC device ID and IP address) indicating the MTC device requesting the data is notified to the communication partner selected by the MME 5 together with the access time intervals TP1 and TP2. On the other hand, information on the selected communication partner (ID and IP address of the MTC device) is also notified to the requesting MTC device together with the access time intervals TP1 and TP2. As a method when the MME 5 selects an appropriate communication partner, an MTC device holding the information requested by the communication request between MTC devices may be selected. In this case, the MTC device that transmits the communication request between MTC devices includes an identifier indicating the type of information desired to be acquired in the message.

Further, the function of the MME 5 that processes the communication request between the MTC devices may be held by the MTC server 2 or other entities (P-GW 7, S-GW 6) in the network 4. In this case as well, as in the case of FIGS. 4 and 5, the MTC device that requests data does not include the ID of the MTC device that is the communication partner in the communication request between MTC devices, but receives the request. The MTC server 2 may select an appropriate communication partner. In this case, the access time intervals TP1 and TP2 are notified to the communication partner selected by the MTC server 2, and information related to the selected communication partner is notified to the MTC device that is the request source and the request destination. .

<Configuration of MTC device 1A>
FIG. 6 is a block diagram showing an example of the configuration of the data transmission source MTC device 1A that receives a request from the data request source MTC device 1B and transmits data to the MTC device 1B in the first embodiment of the present invention. It is. The MTC device 1A illustrated in FIG. 6 includes an interface 101, a setting information acquisition unit 102, a request processing unit 103, a network connection unit 104, an information holding unit 105, and a connection time determination unit 106. . The interface 101 includes lower layer protocol modules directly related to the interface 101 of the MTC device 1A itself. This lower layer protocol module has functions necessary for basic data communication, including mechanisms such as signal modulation, encoding compression, media access control, link layer control, and functions of the entire physical layer and data link layer. Has been implemented.

Also, the setting information acquisition unit 102 has a function for acquiring necessary setting information from the MME 5 when connected to the network 4, and acquires TP1 and TP2 assigned by the MME 5 as access time intervals. When the access time interval TP1 assigned for communication with the MTC server 2 has already been assigned, only the access time interval TP2 assigned for communication with the other MTC device 1B needs to be notified. In addition, an MTC device that does not require assignment of the access time interval TP1 may assign only the access time interval TP2. For example, when the counterpart MTC device 1B does not communicate with the MTC server 2 and communicates only with the MTC device 1A itself, only the access time interval TP2 needs to be assigned to the counterpart MTC device 1B. As another example, when the MTC device 1A itself does not communicate with the MTC server 2 and communicates only with the counterpart MTC device 1B, only the access time interval TP2 needs to be assigned to the MTC device 1A. .

The access time intervals TP1 and TP2 are obtained by a method in which the network 4 side assigns both access time intervals TP1 and TP2 in advance when the MTC device 1A and the MTC device 1B are connected to the network, and the network 4 side is the MTC device 1A. There is a method of assigning in response to a request from 1B. In the former case, the MTC devices 1A and 1B are assigned access time intervals TP1 and TP2 when they first connect to the network 4 or when they first access the MTC server 2. On the other hand, in the latter case, the setting information acquisition unit 102 recognizes that communication with the counterpart MTC device 1B is necessary as shown in FIGS. 5 (11) and 12 (12). A communication request is transmitted to MME 5 to request assignment of access time interval TP2 for communication between MTC devices, and to instruct information holding unit 105 to hold acquired access time intervals TP1 and TP2. The information holding unit 105 has a function of holding information acquired from the MTC server 2 and the MME 5 in addition to the time intervals TP1 and TP2 that can access the network 4, the next connection time determined by the connection time determination unit 106, and the like. Have.

Moreover, the request processing unit 103 has a function of processing an access request received from the MTC server 2 or another MTC device 1B. When a data transmission request is received, it is determined whether the transmission source of the request is the MTC server 2 or the MTC device 1B. If the request source is the MTC server 2, if the timing of receiving the request is within the access time interval TP1 assigned to the communication with the MTC server 2, the request is accepted and responded. On the other hand, if the request source is the MTC device 1B, the request is rejected if the request is received within the access time interval TP1. When the timing of receiving the request is within the access time interval TP2 allocated for communication with the other MTC device 1B, the request is accepted and responded.

As shown in FIG. 3, when the access time interval TP2 is assigned before the access time interval TP1, the request processing unit 103 sends the data requested from the counterpart MTC device 1B to the MTC server 2. May not be transmitted at the access time interval TP1. This is because when the counterpart MTC device 1B transmits to the MTC server 2 data generated in consideration of data acquired from the MTC device 1A, or data including data acquired from the MTC device 1A itself, the MTC device 1A. Can avoid unnecessary data or duplicate transmission of the same data, thereby reducing traffic.

Further, when the access time interval TP2 is assigned before the access time interval TP1, as shown in FIG. 7, the MTC device 1A has all the information held by the MTC device 1A itself in the access time interval TP2. In the case of transmission to the MTC device 1B, it can be determined that it is not necessary to transmit data to the MTC server 2 in the subsequent access time interval TP1 ((4) No data transmission shown in FIG. 3 in FIG. 7). . In these cases, the counterpart MTC device 1B does not need to transmit data to the MTC server 2 in the subsequent access time interval TP1 in the data request transmitted to the MTC device 1A in the access time interval TP2. Information (for example, a flag) may be included. When this information is included in the data request, the MTC device 1A does not need to transmit the data transmitted to the counterpart MTC device 1B in the access time interval TP2 to the MTC server 2 in the subsequent access time interval TP1. to decide. Then, it is determined that only data that has not been transmitted to the counterpart MTC device 1B is transmitted to the MTC server 2. Note that the MTC device 1B may include an identifier representing the type of data requested in the data request.

Further, the connection time determination unit 106 has a function of determining a time (next connection time) at which the MTC device 1A itself connects to the network 4 next time. When the access time interval TP1 is assigned, the MTC device 1A can be disconnected from the network 4 after the communication with the MTC server 2 is completed within the access time interval TP1. Further, when the access time interval TP2 is assigned, it is necessary to accept an access request from another MTC device 1B, so the start time of the access time interval TP2 becomes the next connection time.

In addition, the network connection unit 104 executes processing for newly connecting to the network 4 using the interface 101 and connection processing performed when connecting to the network 4 at the next connection time determined by the connection time determination unit 106. It has a function to do. Further, processing for disconnecting from the network 4 is performed according to an instruction from the connection time determination unit 106.

<Configuration of MTC device 1B>
FIG. 8 is a block diagram showing an example of the configuration of the data request source MTC device 1B that transmits a data request to the data transmission source MTC device 1A and receives data from the MTC device 1A in the first embodiment of the present invention. FIG. The MTC device 1B illustrated in FIG. 8 includes an interface 101, a setting information acquisition unit 102, a data acquisition unit 107, a network connection unit 104, an information holding unit 105, and a connection time determination unit 106. . Since the interface 101 and the setting information acquisition unit 102 are the same as those in the case of the MTC device 1A, description thereof is omitted. As a setting information acquisition method, the setting information acquisition unit 102 recognizes that communication with the counterpart MTC device 1A is necessary as shown in FIGS. 4 (11) and 12 (12). An MTC inter-device communication request is transmitted to the MME 5 to request assignment of an access time interval TP2 for MTC device communication, and to instruct the information holding unit 105 to hold the acquired access time intervals TP1 and TP2.

The connection time determination unit 106 has a function of determining a time (next connection time) when the MTC device 1B itself connects to the network 4 next time. When the access time interval TP1 is assigned, if communication (for example, data transmission) with the MTC server 2 is required, the access time interval TP1 is performed within the access time interval TP1. At this time, within the access time interval TP1, the MTC device 1B can be disconnected from the network 4 after the communication with the MTC server 2 is completed. Further, when the access time interval TP2 for communication between the MTC devices is assigned, it is possible to transmit an access request to the other MTC device 1A, so the next connection within the access time interval TP2 is possible. Determine the time.

In response to the completion of the connection processing from the network connection unit 104 to the network 4, the data acquisition unit 107 refers to the information holding unit 105, and the counterpart MTC device 1 A that is permitted to access within the access time interval TP 2. An access request message (data transmission request) is transmitted. As shown in FIG. 3, when the access time interval TP2 is assigned before the access time interval TP1, the data acquisition unit 107 considers the data acquired from the counterpart MTC device 1A and sends it to the MTC server 2. Data to be transmitted may be generated. For example, when the MTC device 1B is an MTC device having a role of transmitting data to the MTC server 2 instead of the counterpart MTC device 1A, the data including the data acquired from the counterpart MTC device 1A is stored in the MTC server 2 Send to.

<Configuration of MME>
FIG. 9 is a block diagram illustrating an example of the configuration of the MME 5 according to the first embodiment of this invention. The setting information notification unit 502 has a function of assigning access time intervals TP1 and TP2 to the MTC devices 1A and 1B, and when receiving a communication request between MTC devices from the MTC device 1A or MTC device 1B, The access time intervals TP1 and TP2 are determined and notified to the requesting MTC device 1A and the MTC device 1B as the communication counterpart of the MTC device 1A via the interface 501 and held in the information holding unit 503, for example. .

As described above, according to the first embodiment of the present invention, the MTC device 1A and the MTC device 1B are connected between the MTC devices separately from the access time interval TP1 used for communication with the MTC server 2. By assigning the access time interval TP2 used for communication, it is possible to avoid a situation in which communication with another MTC device must be performed simultaneously with communication with the MTC server 2, thereby reducing congestion and packet loss. It becomes possible to make it.

(Second Embodiment)
The network configuration of the second embodiment of the present invention is the same as that of the first embodiment described with reference to FIG. Processing in the second exemplary embodiment of the present invention will be described with reference to FIG. FIG. 10 is a sequence chart illustrating an example of processing when the MTC device 1A, the MTC server 2, and the MTC device 1B perform communication in the second embodiment of the present invention. In the second embodiment, a data transmission request between the MTC devices 1A-1B is made within the access time interval TP1 used for communication with the MTC server 2.
(1) The MTC device 1A and the MTC device 1B receive assignment of access time intervals TP1 and TP2 from the MME 5. The allocated access time intervals TP1 and TP2 are the same as those described in the first embodiment of the present invention.
(2) The MTC device 1A transmits data to the MTC server 2 at the data transmission interval TP11 within the access time interval TP1.

(3) On the other hand, the MTC device 1B sends a data transmission request to the MTC device 1A in the access time interval TP1. When the MTC device 1A receives a data transmission request from another MTC device 1B in the access time interval TP1, it returns only a response message, and does not transmit data in the access time interval TP1. The response message notifies the MTC device 1B that the data request has been accepted, and recognizes that the actual data transmission is performed at the access time interval TP2.
(4) The MTC device 1A performs data transmission for the data request received in the access time interval TP1 in the data transmission interval TP21 within the access time interval TP2. The timing for starting data transmission in the access time interval TP2 can be determined by the MTC device 1A arbitrarily determining. For example, when it is necessary to send data to an MTC device (not shown) other than the MTC device 1B, the MTC device 1A gives priority to the data transmission and then starts data transmission to the MTC device 1B. can do.

<Configuration and Processing of MTC Device 1A>
The configuration of the MTC device 1A according to the second embodiment of the present invention will be described with reference to FIG. The request processing unit 103 has a function of processing an access request received from the MTC server 2 or another MTC device 1B. FIG. 11 is a flowchart showing an example of processing performed by the request processing unit 103 of the MTC device 1A itself in the access time interval TP1 (step S1). If the request is not received within the access time interval TP1 (NO in step S2), the request processing unit 103 ends without doing anything (step S2 → S6). On the other hand, when a request for data transmission is received within the access time interval TP1 (YES in step S2), the request processing unit 103 determines whether the transmission source of the request is the MTC server 2 or the MTC device 1B. (Step S3). If the request source is the MTC server 2 (NO in step S3), the request is accepted and responded, and data transmission is started (step S7).

On the other hand, if the request source is the MTC device 1B (YES in step S3), the request is accepted and a response is returned, but no data is transmitted within the access time interval TP1 (step S4). Further, in this case, the information holding unit 105 is instructed to hold information related to the data transmission request received from the MTC device 1B (step S5). The information held includes the ID and IP address of the MTC device 1B, the type of requested data, and the like. Further, when receiving a request from a plurality of MTC devices, the request processing unit 105 instructs the information holding unit 105 to hold information regarding each request. Note that the request processing unit 103 may include information related to the time to start data transmission in the access time interval TP2 in the response message transmitted to the requesting MTC device 1B. As a result, the requesting MTC device 1B has only to connect to the network 4 immediately before the data transmission from the MTC device 1A is started in the access time interval TP2, so that it connects to the network 4 more than necessary and power consumption increases. Can be prevented.

Further, the request processing unit 103 may include a time interval TP2 in which data transmission is possible in the response message transmitted to the requesting MTC device 1B. That is, the MTC device 1B connects to the network 4 within the accessible time TP1 allocated in advance from the network, and transmits a request message to the MTC device 1A. In this case, the MTC device 1B receives the notification of the access time interval TP2 not from the MME 5 but from the MTC device 1A. Further, the MTC device 1B may transmit a request message to the MTC device 1A via the MTC server 2. The MTC server 2 transfers the request message received from the MTC device 1B to the MTC device 1A. However, when the MTC server 2 receives the request message from the MTC device 1B and the MTC device 1A is not connected to the network 4, the MTC server 2 requests the request after the MTC device 1A connects to the network 4. Forward the message.

Note that the access time interval notified from the MTC device 1A may be the TP2 itself or an arbitrary time interval within the range of the TP2. In the latter case, the MTC device 1A can be divided into a time interval used for communication with the MTC device 1B and a time interval used for communication with the MTC server 2 and other MTC devices. Receiving the notification of the access time interval TP2 from the MTC device 1A, the MTC device 1B connects to the network 4 at the start time of TP2, and waits for data transmission from the MTC device 1A. Alternatively, a request message for requesting data transmission to the MTC device 1A is transmitted again at an arbitrary timing in TP2. Which of these is executed can be instructed by the MTC device 1A. For example, when the MTC device 1A wants to arbitrarily determine the time to communicate with the MTC device 1B in the access time interval TP2, it instructs the MTC device 1B to wait for data from the MTC device 1A. Further, when it is not necessary for the MTC device 1A to specify the time for communication with the MTC device 1B in the access time interval TP2, the MTC device 1A transmits a request to the MTC device 1B at an arbitrary timing in the TP2. Instruct.

Further, the connection time determination unit 106 in FIG. 6 refers to the information holding unit 105 to confirm whether communication with the MTC server 2 or another MTC device 1B is necessary for data transmission or the like. If there is, the MTC device 1A itself has a function of determining the time to connect to the next network (next connection time) and the timing to disconnect. When it is necessary to communicate with the MTC server 2, the allocated access time interval TP1 is confirmed, and an arbitrary timing within the access time interval TP1 is determined as the connection time. At that timing, the network connection unit 104 is instructed to connect to the network 4, and communication with the MTC server 2 is started. If communication is still within the access time interval TP1 after the communication with the MTC server 2 ends, the network connection unit 104 is instructed to disconnect from the network 4. In addition, when communication with other MTC servers other than MTC server 2 is required, after communication with another MTC server is complete | finished, when it is still in access time interval TP1, it will disconnect from the network 4.

Further, when the connection time determination unit 106 confirms that the data transmission request from the MTC device 1B is received in the access time interval TP1 with reference to the information holding unit 105, the connection time determination unit 106 connects to the network in the access time interval TP2. Judge that it is necessary to send data. FIG. 12 is a flowchart illustrating an example of processing performed by the connection time determination unit 106 of the MTC device 1A that has been assigned the access time intervals TP1 and TP2 in the second embodiment of this invention. In FIG. 12, the connection time determination unit 106 refers to the information holding unit 105 at the end of the access time interval TP1, and confirms whether a data transmission request from the MTC device has been received within the access time interval TP1 (step S11, S12). If a data transmission request has not been received (NO in step S12), it is determined that there is no need to connect to the network at the access time interval TP2, and no connection is made to the network at the access time interval TP2 (step S13). If a data transmission request has been received (YES in step S12), an arbitrary timing of the access time interval TP2 is determined as a connection time, and the network connection unit 104 is instructed to connect to the network at that timing (step) S12 → S15), communication with the MTC device 1B is started (step S16). If a data transmission request has been received from another MTC device other than the MTC device 1B, the connection time is determined for each communication partner, and then the data transmission request is first sent to the network. Instruct to connect.

When the connection time determination unit 106 refers to the information holding unit 105 at the end of the access time interval TP1 and confirms that requests are received from a plurality of MTC devices in the access time interval TP1, the access time interval TP2 The order in which data transmission is started can be arbitrarily determined. For example, by confirming the type of requested data and starting data transmission to an MTC device that is requesting high priority data, high priority data can be delivered first. When there is no priority or when the same type of data is requested, data transmission may be started in the order in which the requests are received, or the order may be determined randomly. Also, by starting data transmission first from an MTC device with a large amount of data to be transmitted, even if there is data that takes time to complete transmission, it is possible to control data transmission to be completed within an access time interval. it can.

In addition, the connection time determination unit 106 refers to the information holding unit 105 at the end of the access time interval TP1, and determines that an MTC device that has not received a request in the access time interval TP1 (for example, to transmit data in advance). When there is a transmission partner), it may be determined that data should be transmitted before the MTC device that has received the request. For example, when the time for starting data transmission with the communication partner is already determined in the access time interval TP2, priority is given to transmission to the MTC device, and after the end of the communication, the access time interval TP1 Data transmission to the MTC device that has received the request may be started.

<Configuration and Processing of MTC Device 1B>
The configuration of the MTC device 1B in the second embodiment of the present invention will be described with reference to FIG. The connection time determination unit 106 has a function of determining a time (next connection time) when the MTC device 1B is connected to the network 4 next time. When the access time interval TP1 is assigned, if communication (for example, data transmission) with the MTC server 2 is required, the access time interval TP1 is performed within the access time interval TP1. The connection time determination unit 106 also refers to the information holding unit 105, and when it is confirmed that communication described later with the MTC device 1A is performed in the access time interval TP2, the network time 4 is set at the start time of the access time interval TP2. The network connection unit 104 is instructed to connect to the network. When the MTC device 1A receives a notification of the time when the MTC device 1A starts data transmission to the MTC device 1B, the MTC device 1A instructs the connection unit 104 to connect to the network 4 before that time. Further, as described above, the access time interval TP2 in which data transmission with the MTC device 1A can be performed may be directly notified from the MTC device 1A.

If the data acquisition unit 107 refers to the information holding unit 105 and determines that communication with the counterpart MTC device 1A is necessary, the data acquisition unit 107 transmits a data request to the counterpart MTC device 1A at the access time interval TP1. To do. When receiving a response to the transmitted data request, the information holding unit 105 holds information indicating that communication with the counterpart MTC device 1A is performed in the access time interval TP2. In response to the completion of the connection processing from the network connection unit 104 to the network 4, the data acquisition unit 107 refers to the information holding unit 107 and is permitted to access within the access time interval TP 2. An access request message (data transmission request) is transmitted to 1A.

As described above, according to the second embodiment of the present invention, when the MTC device 1B requests data transmission to the MTC device 1A, it is within the access time interval TP1 used for communication with the MTC server 2. Therefore, the MTC device 1A can determine whether or not it is necessary to connect to the network 4 in the access time interval TP2 used for communication between the MTC devices 1A-1B. As a result, when there is no request from the MTC device 1B, the MTC device 1A does not need to be connected to the network 4 at the access time interval TP2, so that power consumption can be reduced.

(Third embodiment)
Processing in the third exemplary embodiment of the present invention will be described with reference to FIG. FIG. 13 is a sequence chart showing an example of processing when the MTC device 1A, the MTC server 2, and the MTC device 1B perform communication in the third embodiment of the present invention, and FIG. It is a timing chart for explaining processing. In the third embodiment, after the communication with the MTC server 2 is completed in the middle of the access time interval TP1, the MTC device 1A is idle in order to suppress power consumption in the remaining interval of the access time interval TP1. Transition to mode. Further, when another MTC device transmits a request message, the MTC device that is the transmission source can be specified at the paging reception timing, so even if paging is received, connection to the network 4 (transition to the connected mode) is possible. do not have to.

(1) The MTC device 1A and the MTC device 1B receive assignment of access time intervals from the MME 5 (or eNB 3). The allocated time intervals are the paging reception time interval TP1-1 based on the request from the MTC server 2, the paging reception time interval TP1-2 based on the request from the MTC device 2, and the first embodiment of the present invention. There are three access time intervals TP2 described. Note that the paging reception time intervals TP1-1 and TP1-2 are included in the access time interval TP1 described in the first embodiment of the present invention (TP1 = TP1-1 + TP1-2). The paging reception time interval TP1-2 is associated with information related to the MTC device 1B, and indicates a time interval for receiving a request from the MTC device 1B. The allocation method is the same as that described with reference to FIG. 4 and FIG. 5 in the first embodiment of the present invention, and thus the description thereof is omitted.

Further, as described in the second embodiment of the present invention, the MTC device 1B transmits a request message to the MTC device 1A and acquires the paging reception time interval TP1-2 using the response message. Good. In this case, only TP1 or TP1 and TP1-1 are notified to the MTC device 1B, and the MTC device 1B transmits a request message at an arbitrary time in the TP1 or TP1-1. Then, the request message is transmitted again within the paging reception time interval TP1-2 notified by the response message. That is, the MTC device 1A that has received the request message from the MTC device 1B designates the paging reception time interval for the MTC device 1B within the range of the access time interval TP1, and performs manual notification.

13 and 14,
(2) The MTC device 1A transmits data to the MTC server 2 at the transmission interval TP11 within the access time interval TP1.
(3) Then, after the communication with the MTC server 2 is completed in the middle of the access time interval TP1, in order to reduce power consumption in the remaining interval (= TP1-TP11) of the access time interval TP1, the idle mode is entered. Transition.
(4) On the other hand, when MTC device B needs to access MTC device 1A, it sends a data transmission request to MTC device 1A at paging reception time interval TP1-2 within access time interval TP1. .
(5) (6) On the other hand, when the MTC device 1A has received paging in the paging reception time interval TP1-2, the paging is recognized as paging from the MTC device 1B, and from the idle mode in the access time interval TP2. After returning, data transmission to the MTC device 1B is started (transmission interval P21). If paging is not received in the paging reception time interval TP1-2, the connection state is not connected to the network 4 in the access time interval TP2.

<Configuration and Processing of MTC Device 1A>
FIG. 15 is a block diagram showing an example of the configuration of the MTC device 1A according to the third embodiment of the present invention. The MTC device 1A illustrated in FIG. 15 includes an interface 101, a setting information acquisition unit 102, a paging reception unit 108, a network connection unit 104, an information holding unit 105, and a connection time determination unit 106. . The interface 101 includes lower layer protocol modules that are directly related to the interface of the MTC device 1A. This lower layer protocol module has functions necessary for basic data communication, including mechanisms such as signal modulation, encoding compression, media access control, link layer control, and functions of the entire physical layer and data link layer. Has been implemented.

The setting information acquisition unit 102 has a function for acquiring necessary setting information from the MME 5 when connected to the network 4. Here, the access time interval TP1 (= paging reception time interval TP1-1 + TP1-2) and the access time interval TP2 assigned by the MME 5 are acquired as the access time interval. If the access time interval TP1 is already assigned, only the paging reception time intervals TP1-1 and TP1-2 and the access time interval TP2 need be notified. As an acquisition method, there are a method in which the network 4 side allocates these time intervals in advance and a method in which the network 4 side allocates a request from the MTC devices 1A and 1B. In the former case, the MTC devices 1A and 1B are assigned these time intervals when connected to the network 4 and when accessing the MTC server 2.

On the other hand, in the latter case, the setting information acquisition unit 102 performs (1) time interval allocation shown in FIG.
(11) When recognizing that communication with the MTC device 1B is necessary, a communication request between MTC devices is transmitted to the MME 5, and an allocation of an access time interval for communication between MTC devices is requested.
(12) Then, the information holding unit 105 is instructed to hold the access time interval TP1 (= paging reception time interval TP1-1 + TP1-2) and the access time interval TP2 acquired from the MME 5. The notified paging reception time interval is associated with information on the corresponding MTC device (ID or IP address of the MTC device), and the information holding unit 105 holds information on the MTC device corresponding to the paging time interval. Is done. In addition to these time intervals, the information holding unit 105 has a function of holding information acquired from the MTC server 2 and the MME 5, the next connection time determined by the connection time determination unit 106, and the like.
(13) In addition, the MTC device 1B instructs the information holding unit 105 to hold the access time intervals TP1 and TP2 acquired from the MME 5.
Here, procedures (2) to (6) in FIG. 16 are the same as procedures (2) to (6) shown in FIG.

Returning to FIG. 15, when the paging reception unit 108 receives the paging transmitted from the MME 5, if the received timing is within the paging reception time interval TP1-2, the access request from the counterpart MTC device 1B Therefore, the information holding unit 105 holds information indicating that the data request is transmitted from the counterpart MTC device 1B.

In addition, the connection time determination unit 106 refers to the information holding unit 105 and confirms whether communication with the MTC server 2 or another MTC device 1B is necessary for data transmission or the like. Has a function of determining the time when the MTC device 1A itself connects to the network 4 next time (next connection time) and the timing of disconnection. When it is necessary to communicate with the MTC server 2, the allocated access time interval TP1 is confirmed, and an arbitrary timing within the access time interval TP1 is determined as the connection time. At that timing, the network connection unit 104 is instructed to connect to the network 4, and communication with the MTC server 2 is started. After the communication with the MTC server 2 is completed, if it is still within the time interval of the access time interval TP1, the network connection unit 104 is instructed to shift to the idle mode.

When the connection time determination unit 106 refers to the information holding unit 105 and confirms that paging is received at the paging reception time interval TP1-2, the connection time determination unit 106 connects to the network 4 at the access time interval TP2, and It is determined that it is necessary to transmit data to the destination MTC device 1B. FIG. 17 shows an example in which the MTC device 1A assigned the access time interval TP1 (= paging reception time interval TP1-1 + TP1-2) and the access time interval TP2 in the third embodiment of the present invention It is a flowchart which shows an example of the process performed when TP1 is complete | finished (step S11).

In FIG. 17, the connection time determination unit 106 refers to the information holding unit 105 at the end of the access time interval TP1, and confirms whether or not paging has been received within the paging reception time interval TP1-2 (step S12a). If not (NO in step S12a), it is determined that it is not necessary to connect to the network 4 in the access time interval TP2, and the network is not connected in the access time interval TP2 (steps S13 and S14). If there is (YES in step S12a), an arbitrary timing of the access time interval TP2 is determined as a connection time (step S15), the network connection unit 104 is instructed to connect to the network 4 at that timing, and paging reception is performed. Communication with the counterpart MTC device 1B corresponding to the time interval TP1-2 is started (step S16).

In addition, the network connection unit 104 executes processing for newly connecting to the network 4 using the interface 101 and connection processing performed when connecting to the network 4 at the next connection time determined by the connection time determination unit 106. It has a function to do. Further, according to an instruction from the connection time determination unit 106, processing for disconnecting from the network 4 and processing for transitioning to the idle mode are performed.

<Configuration and Processing of MTC Device 1B>
The configuration of the MTC device 1B according to the third embodiment of the present invention will be described with reference to FIG. The connection time determination unit 106 has a function of determining a time (next connection time) when the MTC device 1B itself connects to the network 4 next time. When the access time interval TP1 is assigned, if communication (for example, data transmission) with the MTC server 2 is required, the access time interval TP1 is performed within the access time interval TP1. In addition, the connection time determination unit 106 refers to the information holding unit 105, and when it is confirmed that communication described later with the counterpart MTC device 1A is performed in the access time interval TP2, the start time of the access time interval TP2 The network connection unit 106 is instructed to connect to the network 4.

If the data acquisition unit 108 refers to the information holding unit 105 and determines that communication with the counterpart MTC device 1A is necessary, the data acquisition unit 108 transmits data addressed to the counterpart MTC device 1A at the paging reception time interval TP1-2. Send a request. Further, although the response to the transmitted data request is not received, information indicating that communication with the counterpart MTC device 1A is performed in the access time interval TP2 is held in the information holding unit 105.

Note that the MTC device 1B according to the third embodiment of the present invention does not recognize the paging reception time intervals TP1-1 and TP1-2 like the MTC device 1B according to the second embodiment of the present invention. When only the access time interval TP1 is recognized, the request transmitted by the MTC device 1B itself may reach the MTC device 1A within the paging reception time interval TP1-1 from the MTC server 2. In this case, the MTC device 1A misrecognizes paging by a request from the MTC device B as paging by a request from the MTC server 2.

The procedures (11), (12), and (13) in (1) time interval allocation shown in FIG. 18 are the same as the procedures (11), (12), and (13) described in FIG.
(11) When the MTC device 1B wants to communicate with the MTC device A, the MTC device 1B first transmits to the MME 5 (or the MTC server 2) an inter-MTC device communication request indicating communication with the MTC device 1A.
(12) (13) When the MME 5 receives the communication request between the MTC devices, the MME 5 prevents the access to the MTC device 1A by the MTC device 1B from affecting the communication with the MTC server 2 by the MTC device 1A. The access time intervals TP1 and TP2 are both assigned to the MTC device 1B and the MTC device 1A.
In addition, procedures (2) to (6) in FIG. 18 are the same as procedures (2) to (6) shown in FIG.

Therefore, this problem can be solved by transferring the request message for data transmission between the MTC devices 1A and 1B via the MTC server 2. Assume that the MTC device 1B transmits a request message for the MTC device 1A to the MTC server 2 within the access time interval TP1. When the MTC server 2 receives the request message within the paging reception time interval TP1-1, the request message is not immediately transferred to the MTC device 1A, but the range of the paging reception time interval TP1-2 from the MTC device. Then, the data is transferred to the MTC device 1A. Thereby, the MTC device 1A can reliably receive the paging by the request message from the MTC device 1B within the range of the paging reception time interval TP1-2.

As described above, according to the third embodiment of the present invention, when the MTC device 1B makes a data request to the MTC device 1A, the transmission source can be specified based on the timing of receiving the paging. Therefore, the MTC device 1A can make a transition to the idle mode immediately after the communication with the MTC server 2 is completed, and the power consumption can be suppressed.

Each functional block used in the description of the above embodiment is typically realized as an LSI that is an integrated circuit. These may be individually made into one chip, or may be made into one chip so as to include a part or all of them. Although referred to as LSI here, it may be referred to as IC, system LSI, super LSI, or ultra LSI depending on the degree of integration. Further, the method of circuit integration is not limited to LSI's, and implementation using dedicated circuitry or general purpose processors is also possible. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI, or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used. Further, if integrated circuit technology comes out to replace LSI's as a result of the advancement of semiconductor technology or a derivative other technology, it is naturally also possible to carry out function block integration using this technology. For example, biotechnology can be applied.

The present invention has an effect of reducing congestion and packet loss when data is transmitted from a plurality of communication devices to a data collection server via a wireless network and data is communicated between the communication devices. It can be used for 3GPP (3rd Generation Partnership Project) MTC (Machine Type Communication).

Claims (19)

1. A communication method for transmitting data from a plurality of communication devices to a data collection server via a wireless network and communicating data between the communication devices,
   A first access time interval for transmitting each data from the plurality of communication devices to the data collection server from a management node that manages the plurality of communication devices to the plurality of communication devices, and the plurality of communication Assigning a second access time interval for transmitting and receiving each piece of data between devices;
   The plurality of communication devices transmitting each piece of data to the data collection server in the assigned first access time interval;
   Transmitting and receiving data between the plurality of communication devices in the allocated second access time interval; and
   Communication method having.
2. The assigning step dynamically sets the first and second access time intervals when there is a request from the plurality of communication devices to transmit / receive each data between the plurality of communication devices. 2. The communication method according to claim 1, wherein the communication method is assigned to the plurality of communication devices.
3. 3. The communication method according to claim 1, wherein the assigning step assigns the second access time interval ahead of the first access time interval.
4. The communication device of the data request source transmits a data transmission request to the communication device of the data transmission source in the first access time interval;
   The communication method according to claim 1, wherein the data transmission source communication device transmits data to the data request source communication device in the second access time interval.
5. In the allocation step, the management node sets the first access time interval, the management node calls the communication device that is the data transmission source, and the communication device that is the data request source transmits the data. Dividing into a second paging time interval for calling the communication device of the transmission source and assigning to the plurality of communication devices;
   When the communication device that transmits data to the data collection server ends the data transmission in the middle of the first access time interval, the communication device enters the idle mode in the remaining time interval within the first access time interval. And when the data request is received from the data requesting communication device in the second paging time interval, the data request source data is returned from the idle mode in the second access time interval. The communication method according to claim 1, wherein data is transmitted to the communication device.
6. A communication system for transmitting data to a data collection server from a plurality of communication devices via a wireless network and communicating data between the communication devices,
   A first access time interval for transmitting each data from the plurality of communication devices to the data collection server from a management node that manages the plurality of communication devices to the plurality of communication devices, and the plurality of communication Allocating means for allocating a second access time interval for transmitting and receiving each data between devices;
   Means for the plurality of communication devices to transmit each data to the data collection server in the assigned first access time interval;
   Means for transmitting and receiving data between the plurality of communication devices in the allocated second access time interval;
   Communication system having.
7. The allocating unit dynamically sets the first and second access time intervals when the management node makes a request to transmit / receive data between the plurality of communication devices from the plurality of communication devices. The communication system according to claim 6, wherein the communication system is assigned to the plurality of communication devices.
8. The communication system according to claim 6 or 7, wherein the assigning means assigns the second access time interval before the first access time interval.
9. The communication device of the data request source transmits a data transmission request to the communication device of the data transmission source in the first access time interval;
   The communication system according to claim 6 or 7, wherein the data transmission source communication device transmits data to the data request source communication device in the second access time interval.
10. The assigning means includes: a first access time interval for the management node; a first paging time interval for the management node to call the communication device that is a data transmission source; Dividing into a second paging time interval for calling the communication device of the transmission source and assigning to the plurality of communication devices;
    When the communication device that transmits data to the data collection server ends the data transmission in the middle of the first access time interval, the communication device enters the idle mode in the remaining time interval within the first access time interval. And when the data request is received from the data requesting communication device in the second paging time interval, the data request source data is returned from the idle mode in the second access time interval. The communication system according to claim 6, wherein data is transmitted to the communication device.
11. The communication device in a communication system that transmits data to a data collection server from a plurality of communication devices via a wireless network and communicates data between the communication devices,
    A first access time interval for transmitting each data from the plurality of communication devices to the data collection server from a management node that manages the plurality of communication devices to the plurality of communication devices, and the plurality of communication Means for accepting assignment when a second access time interval for transmitting and receiving data between devices is assigned;
    Means for transmitting each data to the data collection server in the assigned first access time interval;
    Means for transmitting and receiving data between the other communication devices in the allocated second access time interval;
    Having a communication device.
12. Means for transmitting a request to transmit / receive each data among the plurality of communication devices to the management node;
    Means for accepting the assignment when the first and second access time intervals are dynamically assigned by the management node in response to the request;
    The communication device according to claim 11, further comprising:
13. When the second access time interval is assigned to be earlier than the first access time interval, data is transmitted to the other communication device in the second access time interval assigned earlier. 13. The method according to claim 11, further comprising determining whether or not it is necessary to transmit data to the server in the first access time interval assigned later and not transmitting the data when it is unnecessary. Communication device.
14. When the communication device is a data requesting source, a data request for the communication device of a data transmission source is transmitted in the first access time interval,
    13. The communication device according to claim 11, wherein when the communication device is the data transmission source communication device, data is transmitted to the data request source communication device in the second access time interval.
15. The management node uses the first access time interval, the management node calls the communication device that is the data transmission source, the first paging time interval, and the communication device that is the data request source uses the communication that is the data transmission source. Accepting the assignment when assigned to the plurality of communication devices divided into second paging time intervals for calling the device;
    In the case of the communication device that transmits data to the data collection server, when the data transmission is terminated in the middle of the first access time interval, the remaining time interval within the first access time interval. When transitioning to the idle mode and receiving a data request from the communication device that is a data transmission request source in the second paging time interval, the data is returned from the idle mode in the second access time interval and data is transferred to the data The communication device according to claim 11, wherein the communication device transmits data to a communication device that is a transmission request source.
16. A management node for managing the plurality of communication devices in a communication system for transmitting data from a plurality of communication devices to a data collection server via a wireless network and communicating data between the communication devices;
    A first access time interval for transmitting each piece of data from the plurality of communication devices to the data collection server and a first number for transmitting / receiving each piece of data between the plurality of communication devices to the plurality of communication devices. Assigning means for assigning two access time intervals,
    Management node that has.
17. The assigning means dynamically assigns the first and second access time intervals when there is a request from the plurality of communication devices to transmit / receive data between the plurality of communication devices. The management node according to claim 16, wherein the management node is assigned to the management node.
18. The management node according to claim 16 or 17, wherein the assigning means assigns the second access time interval before the first access time interval.
19. The assigning means includes the first access time interval, a first paging time interval for the management node to call the communication device that is a data transmission source, and the communication device that is a data request source is the data transmission source. The management node according to claim 16 or 17, wherein the management node is divided into second paging time intervals for calling a communication device and assigned to the plurality of communication devices.

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