JP6177933B2 - COMMUNICATION DEVICE AND COMMUNICATION CHANNEL AND SLOT ALLOCATION METHOD - Google Patents

Description

  The present invention relates to a communication device, a communication channel, and slot allocation control in a communication network system.

  Along with the spread and diversification of network usage, in systems such as AMI (Advanced Metering Infrastructure) and sensor networks, a system has been built that can accommodate multiple terminals under the gateway and collect data from these terminals. Has been. In addition, from the viewpoint of effective utilization of radio resources and cost reduction in network construction, there are examples in which a system is constructed by sharing a network of existing systems when a new system is introduced.

  When a plurality of different systems share a network, communication of one system may interfere with communication of another system, leading to a decrease in communication success rate and throughput of both systems. For this reason, when a new system is introduced while sharing the network of the existing system, it is important to consider so as not to cause interference with the communication of the existing system.

  As a technique for avoiding communication interference, TDMA (Time Division Multiple Access) is known. This technology can avoid communication interference by time-dividing a finite-length communication frame into unit time slots, and allocating dedicated slots to each terminal to schedule communication. Furthermore, when a plurality of communication channels can be used on the network, finer scheduling can be performed by combining channel division.

  As a technique that focuses on the problem of interference between terminals, a technique is known in which a network station holds a schedule of a plurality of patterns in advance and assigns any schedule to a terminal that has detected interference (Patent Document 1). ). In particular, in this technique, when a terminal detects interference even after assigning a schedule, the network station assigns another schedule to the terminal. By repeating this series of processing, it is possible to realize schedule allocation for avoiding communication interference with each terminal. This is a technology that assumes interference between terminals that use radio schemes that are close to each other in frequency bands, but a network station that holds a schedule of multiple patterns even with interference between terminals that use the same radio scheme, Alternatively, it can be applied by preparing a management device.

WO10 / 073325

  As described in Patent Document 1, when a new schedule is assigned to each terminal that detects interference, a terminal that is already operating based on a specific schedule may be forced to change the schedule. . For example, when a new system sharing a network enters, not only terminals belonging to the new system but also schedule changes of terminals belonging to the existing system may be required. In addition, when some terminals in the existing system change the schedule according to the entry of the new system, even if the terminal of the existing system does not directly interfere with the communication of the new system, the terminal whose schedule has been changed As a result, it may be necessary to change the schedule of each terminal in the entire system. In particular, in the case of a large-scale system with a large number of terminals such as AMI, the overhead of reviewing the schedule and reallocating the schedule to each terminal becomes large. Therefore, it is desirable to design the system so that it is not necessary to change the schedule of the terminals belonging to the existing system as much as possible when determining the schedule of the system newly entering the network.

  Therefore, the present invention realizes allocation of communication channels and slots by preventing interference that occurs when a new system or terminal is added to the network, and avoiding a schedule change for terminals belonging to an existing system. It is in.

The communication apparatus according to the present invention is preferably a communication apparatus that allocates a communication channel and a slot for transferring a packet from another communication apparatus on the transfer path,
A channel / slot management table for managing communication channels and slots used by the own communication device and other communication devices existing in the interference range;
When there is a request for allocation of a communication channel and slot from another communication device at the time of transfer of the packet, the channel / slot management table of the own communication device and the channel of the adjacent transfer source communication device on the transfer path A means for referring to the slot management table and extracting available channels and available slots for packet transfer;
The communication apparatus includes a communication channel and a slot that are selected from an empty channel and an empty slot according to an allowable delay time and traffic characteristics of the packet.

The communication channel and slot allocation method according to the present invention preferably includes the first system including at least a first communication device that can be connected to an application server via a network, and the first system. And a second system including at least a second communication device that can be connected to the communication device included in the communication network, the packet transferred from the second communication device of the second system, A method for assigning a communication channel and a slot of a communication device when transferring to the first communication device of a first system,
Managing communication channels and slots used by the first and second communication devices and other communication devices existing in the interference range using a channel / slot management table;
The second communication device of the second system is selected from the empty channels and empty slots of the communication devices on the path to the first communication device and the first communication device of the first system. Requesting the first communication device to allocate a communication channel and a slot for transferring a packet within an allowable delay time;
The communication device that has received the allocation request can use it for packet transfer by referring to the channel / slot management table of its own communication device and the channel / slot management table of the adjacent transfer source communication device on the path. Extracting a free channel / slot,
The communication channel and slot allocation method includes a step of allocating a communication channel and a slot selected from vacant channels and vacant slots according to the allowable delay time and traffic characteristics of the packet.

  According to the present invention, it is possible to prevent communication interference between an existing system and a new system, and to realize assignment of communication channels and slots while avoiding schedule changes for terminals belonging to the existing system.

It is a block diagram which shows a communication network system. It is a block diagram which shows a communication network system. It is a hardware block diagram of a terminal. It is a hardware block diagram of a gateway. It is a figure which shows the structural example of a channel slot management table. It is a figure which shows the format of the packet used for a communication channel and slot allocation. 4 is a flowchart illustrating a communication channel and slot allocation control operation in the first embodiment. It is a flowchart which shows the operation | movement which extracts an empty channel and an empty slot from the packet and slot management table of a packet transfer source and a transfer destination. It is a figure which shows the extraction result of a channel / slot management table and an empty channel and an empty slot. FIG. 7 is a sequence diagram illustrating operations of communication channels and slot allocation in the first embodiment. 10 is a flowchart illustrating a communication channel and slot allocation control operation in the second embodiment. FIG. 10 is a sequence diagram illustrating operations of communication channel and slot assignment in the second embodiment. FIG. 10 is a block diagram illustrating a communication network system according to a third embodiment. 10 is a flowchart illustrating a communication channel and slot allocation control operation in the third embodiment. FIG. 10 is a sequence diagram illustrating operations of communication channel and slot assignment in the third embodiment. FIG. 10 is a diagram illustrating a configuration example of a channel / slot management table and a usage time management table in the fourth embodiment. 14 is a flowchart illustrating an operation of extracting empty channels / slots from a packet transfer source / destination channel / slot management table according to the fourth embodiment.

First, an outline of a communication network system according to a preferred embodiment of the present invention will be described.
In a communication network system where an existing system and a new system share a network, when a packet generated in the new system is transferred to a higher-level application server via the gateway of the existing system, the packet is sent from the gateway of the new system to the gateway of the existing system. Allocate communication channels and slots for transferring Furthermore, since the packet has an allowable delay time Dt, the maximum delay time Tmax from the gateway of the existing system to the upper application server is within the time X defined by X = Dt−Tmax. Transfer packets from the gateway to the gateway of the existing system.

  Therefore, the gateway of the new system is used to transfer the packet within X from the empty channel / slot to the gateway of the existing system to the gateway of the existing system and the terminal on the route to the gateway. Request to allocate communication channels and slots. The terminal and the gateway manage communication channels and slots used by themselves and neighboring terminals existing within a range of interference with the terminal and the gateway in the channel / slot management table. In each link on the path from the gateway of the new system to the gateway of the existing system, the channel / slot management table of the transfer source and transfer destination on the link is referred to extract an empty channel / slot at time X. Communication channels and slots for packet transfer are allocated on each link within the range. At this time, the slot allocation order is defined according to the traffic characteristics of the existing system and the new system.

  Regarding this traffic characteristic, when the traffic load of the existing system is lower than the traffic load of the new system, it is desirable to transmit the packet as soon as possible without accumulating the packet at the gateway of the new system. Therefore, in this case, among the links on the route from the gateway of the new system to the gateway of the existing system, the communication channel and slot for transfer are secured within the range that falls within time X in order from the link close to the gateway of the new system. . At this time, the empty channel / slot slot is secured in order from the earliest slot number.

  On the other hand, if the traffic load of the existing system is higher than the traffic load of the new system, from the viewpoint of reducing bandwidth consumption by communication of the new system, packets are accumulated for as long as possible at the gateway of the new system, and more packets are stored. It is desirable to combine them into one (aggregation) and transmit them together. Therefore, in this case, among the links on the route from the gateway of the new system to the gateway of the existing system, the communication channel and slot for transfer are secured within the range that falls within time X in order from the link close to the gateway of the existing system. . At this time, the empty channel and the empty slot are secured in order from the slowest slot number.

  In a preferred example of the present invention, the communication channel and slot allocation processing is performed by autonomous distributed control between the gateway and the terminal, or centralized control by the management device. In each link on the route from the gateway of the new system to the gateway of the existing system, when the assignment of the communication channel and slot for transfer is completed, the packet regarding the new system is not interfered with the communication of the existing system and the packet is allowed. It is possible to deliver to the upper application server within the delay time.

  Hereinafter, a communication network system configuration, a terminal and a gateway, a table configuration, a packet configuration, a communication channel, and slot allocation control according to a preferred embodiment (Examples 1 to 4) will be described with reference to the drawings. The terminal and the gateway may be collectively referred to as a communication device.

  In the first embodiment, when the traffic load of the existing system is lower than the traffic load of the new system, communication channels and slot allocation are realized by autonomous distributed control between the gateway and the terminal. When it is difficult for the terminal to frequently notify the information on the channel / slot management table to the management device, such as when a multi-hop network is constructed in a narrow-band environment or when the number of terminals is large, concentration by the management device Instead of control, autonomous distributed control as in the present embodiment is effective. When the traffic load of the existing system is lower than the traffic load of the new system, it is desirable to transmit the packet as soon as possible without accumulating the packet at the gateway of the new system from the viewpoint of reducing the delay time.

  First, a configuration of a communication network system, a terminal, and a gateway will be described with reference to FIGS. Next, a channel / slot management table will be described with reference to FIG. 5, and a packet format will be described with reference to FIG. Thereafter, communication channel and slot allocation control and an operation example thereof will be described with reference to FIGS.

  FIG. 1 is a configuration example of a communication network system configured by one system. In FIG. 1, a communication network system 1 includes a gateway 400 connected to an application server 100 via a network and a plurality of terminals 300-a to 300-f (hereinafter collectively referred to as 300) connected hierarchically to the gateway 400. May be configured). The gateway 400 is connected to the application server 100 and some of the terminals 300-a and 300-b so as to be able to communicate wirelessly or by wire. Data collected from the terminal 300 is transmitted to the application server 100 via the gateway 400. Here, a network composed of the gateway 400 and the terminal 300 is referred to as a field area network (hereinafter referred to as FAN). In the illustrated example, the topology of the tree structure is such that the terminal 300 is connected in a form branched from the root gateway 400, but the topology may be a mesh structure or the like.

  FIG. 2 is a configuration example of a communication network system including a plurality of systems. In FIG. 2, the communication network system 2 is configured by connecting the FAN 1 of the system 31 to the application servers 201 and 202 that operate, respectively, and further connecting the FAN 1 of the system 32 to the FAN 1. Each of the systems 31 and 32 includes a gateway 400-1 and a gateway 400-2, and terminals 300-1a to 1f and terminals 300-2a to 2d that are hierarchically configured under each gateway. Data collected from the terminals 300-1a to 1f is transmitted to the application server 201 via the gateway 400-1.

  On the other hand, data collected from the terminals 300-2a to 2d belonging to the system 32 is transmitted to the gateway 400-2, and further passes through the plurality of terminals 300-1d and 300-1a belonging to the system 31 from the gateway 400-2. The data is transferred to the gateway 400-1 and transmitted to the application server 202. That is, the data transmitted from the terminals 300-2a to 2d of the system 32 is transmitted to the application server 202 in a form that shares the FAN1 of the system 31.

  In the present embodiment, a system 31 composed of an application server 201, a gateway 400-1, and terminals 300-1a to 1f exists as an existing system, and each of the terminals 300-1a to 1f is assigned to a communication channel assigned thereto. And it is assumed that communication is performed according to the slot so as not to cause interference. Then, it is assumed that a new system 32, that is, a system including the application server 202, the gateway 400-2, and the terminals 300-2a to d is newly added to the system 31.

In this embodiment, a technology for assigning communication channels and slots, which is required when the transmission data of the terminals 300-2a to 2d belonging to the system 32 is transferred from the gateway 400-2 to the gateway 400-1 in the system 31. Is described. (In the following description, the existing system 31 and the new system 32 may be called.)
In the illustrated example, the communication network system is configured by two FAN systems, but may be configured by three or more systems. Further, FAN1 and FAN2 may be configured separately by using different communication channels. However, in this case, since the gateway 400-2 belongs to both FAN1 and FAN2, the communication using FAN1 and FAN2 is performed using the communication channels used by the two FANs.

FIG. 3 shows a hardware configuration of the terminal 300.
The terminal 300 is an embedded device having a communication function with the gateway 400 or another terminal 300. The terminal 300 includes a microcomputer 301, a clock generation circuit 308, a power supply circuit 309, and a transmission / reception circuit 310. The microcomputer 301 includes a ROM 302 and a RAM 307, and is connected to the clock generation circuit 308, the power supply circuit 309, and the transmission / reception circuit 310.

  The ROM 302 is a storage device including a read-only semiconductor memory. The ROM 302 includes a central control unit 303, a communication processing unit 304, a path management unit 305, and a communication channel / slot management unit 306, and is connected to the RAM 307. The central control unit 303 controls execution of programs in the ROM 302. The central control unit 303 is connected to the communication processing unit 304, the path management unit 305, and the communication channel / slot management unit 306.

  The communication processing unit 304 performs transmission / reception processing in communication. Specifically, the communication processing unit 304 performs packet analysis processing such as packet assembly processing such as transmission destination designation at the time of transmission and determination of whether or not the packet is addressed to the own terminal at the time of reception. The route management unit 305 manages a route in communication within the network. The communication channel / slot management unit 306 has a channel / slot management table 500 (see FIG. 5), and the communication channel and slot usage status of the own channel and the communication used by the neighboring terminals existing in the range where the communication channel / slot management unit 306 interferes with itself. Manage channels and slots. The RAM 307 is a storage device such as a rewritable semiconductor memory element, and is used as a transmission / reception buffer in communication.

  The clock generation circuit 308 is connected to the power supply circuit 309, the microcomputer 301, and the transmission / reception circuit 310, and generates a clock used by the microcomputer 301 and the transmission / reception circuit 310. The power supply circuit 309 is connected to the clock generation circuit 308, the microcomputer 301, and the transmission / reception circuit 310, and supplies power to each unit. The transmission / reception circuit 310 is connected to the clock generation circuit 308, the power supply circuit 309, and the microcomputer 301, and transmits and receives signals. When performing wireless communication, the RF peripheral circuit corresponds to the transmission / reception circuit 310. Note that the terminal 300 may be an independent device instead of an embedded device.

FIG. 4 shows the hardware configuration of the gateway.
The gateway 400 communicates with the terminal 300 and the application server, and collects data from the terminal 300. The hardware configuration of the gateway 400 is the same as that of the terminal 300 except that the external network connection circuit 411 is mounted. The external network connection circuit 411 is a function for using an external network such as Ethernet (registered trademark), WiFi (registered trademark), an optical line, and a telephone network. However, it is not always necessary to mount the external network connection circuit 411 for the gateway 400-2 of FIG.

FIG. 5 shows a channel / slot management table held by the terminal and the gateway.
The channel / slot management table 500 is held in the communication channel / slot management unit 306 of the terminal 300 and the gateway 400, and is used by the neighboring terminals existing in the communication channel / slot usage status and in the range of interference with itself. Manage existing communication channels and slots.

  In the channel / slot management table 500, a communication channel 501 indicates a communication channel that can be used in the FAN to which the channel belongs, and a slot 502 indicates a slot number when a finite-length communication frame is time-divided into unit time slots. Yes. “0” is registered in the channel / slot management table 500 for an empty channel / empty slot that is not used by itself or a neighboring terminal existing in a range where it interferes with itself. For example, if the slot number Z of the communication channel Y is represented as (Y, Z), (C1, S1) is “0” in the example of FIG. Indicates that there is.

  In the channel / slot management table 500, “1” is registered in the channel / slot used by itself for transmission or reception. In the example shown in the figure, (C2, S1) is “1”, which is assigned for transmission or reception. The transmission / reception circuit 310 of FIG. 3 and FIG. 4 is separated for transmission and reception, and in a certain slot unless a special mechanism for receiving another packet at the same time is provided while transmitting a packet. When “1” is assigned, even if a frame of “0” exists in another channel of the same slot, it cannot be used by itself. Hereinafter, in the present embodiment, description will be made on the assumption that the terminal and the gateway are not provided with a mechanism for simultaneous transmission and reception.

  In the channel / slot management table 500, “2” is registered in the channel / slot used by a neighboring terminal existing in a range where it interferes with itself. In the example shown in the figure, (C3, S1) is “2”, which is a channel / slot used by a neighboring terminal, and therefore cannot be used for transmission / reception. If it is decided that a free channel / slot in which “0” has been registered so far is newly used, neighboring terminals existing in a range where it interferes with itself will not use the channel / slot. In addition, the neighboring terminal is notified of the new reservation by broadcast or multicast. The neighboring terminal that has received this notification registers “2” in the corresponding channel slot in the management table 500 held by itself. In this embodiment, the channel / slot use status is identified by the notation of “0”, “1”, “2”, but other identifiers may be used.

FIG. 6 shows a format of a packet used for communication channel and slot allocation.
The packet 600 includes a header 601 and a payload 602. The header 601 includes a destination address 603, a final destination address 604, a transmission source address 605, a transmission source address 606, a packet ID 607, a slot allocation order flag 608, an allocation range start slot number 609, an allocation range end slot number 610, and a traffic ID 611. Consists of However, if other fields such as packet length and TTL (Time To Live) are necessary, they may be added to the header as appropriate. That is, the configuration of the header is not particularly limited as long as it includes fields equivalent to the destination address 603 to the traffic ID 611. The header configuration may be a header including a MAC header and an IP header.

  A destination address 603 is a field for registering a destination address or ID in communication between links. An identifier such as an address or ID registered in this field is made to conform to the method adopted in the communication system. If the ID is identified by the IP address, MAC address or unique ID, the ID may be registered.

  The final destination address 604 is a field for registering the final destination address or ID of the packet. For example, when the gateway 400-2 in FIG. 2 requests allocation of a communication channel and a slot necessary for transferring a packet to the gateway 400-1, the address or ID of the gateway 400-1 is assigned to the final destination address 604. sign up.

The transmission source address 605 is a field for registering the address or ID of the transmission source that relayed the packet. When a terminal or gateway as a transmission source transmits, the transmission source address or ID is registered in the transmission source address 605.
The source address 606 is a field for registering the source address or ID of the packet.

  The packet ID 607 is a field for registering an ID used for packet identification. The packet ID 607 is registered by the transmission source, and the sequence number used for the IP header corresponds to the packet ID. When the same packet with the same source address 606 and packet ID 607 is received, the packet is discarded.

  The slot allocation order flag 608 is a flag that prescribes whether to secure in order from the earliest among the empty slots or in order from the latest. “0” is registered in order from the earliest, and “1” is registered in order from the latest. The flag value to be registered is determined based on, for example, comparison of the traffic load between the existing system and the new system. If the traffic load of the existing system is lower than the traffic load of the new system as in this embodiment, the new system Since it is desirable to transmit the packet as soon as possible without accumulating the packet at the gateway, “0” is registered in the slot allocation order flag 608 so as to reserve the empty slots in order from the earliest. On the other hand, when the traffic load of the existing system is higher than the traffic load of the new system, “1” is registered in the slot allocation order flag 608, and it is defined that the empty slots are secured in order from the latest. The latter will be described in detail in Example 2.

  The allocation range start slot number 609 is a field for registering the slot number which is the start point of the slot range to which allocation is desired when a communication channel and slot allocation request is made. For example, in the channel / slot management table of FIG. 5, when allocation is desired in slots after slot number S3, “3” is registered in start slot number 609 of the allocation range.

  The allocation range end slot number 610 is a field for registering a slot number which is an end point of a slot range to be allocated when a communication channel and slot allocation request is made. For example, in the channel / slot management table of FIG. 5, when allocation is desired in a slot before slot number S10, “10” is registered in end point slot number 610 of the allocation range.

  The traffic ID 611 is a field for registering an ID used for identifying the traffic type of the packet. The traffic ID 611 is registered by the transmission source. For example, in the case of a traffic packet related to the system 32 transmitted by the terminal 300-2a in FIG. 2, “2” is registered in the traffic ID 611. However, if the allowable delay is different among the packets related to the same system and there are a plurality of traffic types, the traffic ID may be defined with a finer granularity. By providing this traffic ID 611, it becomes possible for a terminal or a gateway to manage in which communication channel / slot each traffic packet should be transferred.

  The payload 602 stores a slot / channel management table 612. In this field, information related to the slot / channel management table of the transmission source terminal is registered. However, it is not always necessary to register information regarding all slots, and in order to reduce the packet length, information on the slot / channel management table in the range specified by the start slot number 609 of the allocation range and the end slot number 610 of the allocation range You may register only. The payload 602 may store not only the slot / channel management table 612 but also application data as necessary.

Next, the communication channel and slot allocation control operation will be described with reference to FIG.
In order to transmit the packet of the new system 32 to the application server via the FAN 1 of the existing system 31, communication channels and slots are allocated in advance according to the control operation of FIG. In the communication channel and slot allocation control in the first embodiment, in order to secure in order from the earliest possible slot, among the links on the path from the gateway 400-2 of the new system 32 to the gateway 400-1 of the existing system 31, The communication channel and slot for transfer are secured in order from the link closest to the gateway of the new system. This control operation is performed by the communication channel / slot management unit 306 of the terminal 300 or the gateway 400 that has received the channel / slot allocation request packet.

  In FIG. 7, step 701 calculates the range of slots that need to be allocated when the gateway 400-2 of the new system 32 delivers a packet received from a terminal connected to the subordinate system to the application server within the allowable delay time. It is processing to do. Since there is an allowable delay time Dt until the packet is delivered to the upper application server, when the maximum delay time from the gateway 400-1 of the existing system 31 to the upper application server is Tmax, X = Dt− It is necessary to transfer the packet from the gateway of the new system to the gateway of the existing system within the time X defined by Tmax. Therefore, the communication channel / slot management unit 306 of the gateway 400-2 of the new system 32 calculates the time X based on the allowable delay time Dt and the maximum delay time Tmax, and receives a packet from a terminal connected to itself. Starting from the time, it is calculated how many slots the slot allocation needs to be requested. This slot range can be calculated with Floor (X / St) when the slot width used by the terminals belonging to the existing system 31 is St (Floor is a function that rounds off the decimal point). The gateway designates a number obtained by adding the value of Floor (X / St) to the start slot number of the allocation range as the end slot number of the allocation range. The starting slot number of the allocation range is a number obtained by adding 1 to the slot number for receiving a packet from a terminal connected to the gateway of the new system. When the gateway of the new system calculates the range of slots for which allocation is requested, the process proceeds to step 702.

  In step 702, the gateway 400-2 of the new system 32 creates a channel / slot allocation request packet according to the packet format of FIG. 6, and stores the transfer destination stored in the route management unit 305 (if the topology is a tree structure, the parent terminal ) To the created channel / slot allocation request packet.

  Regarding the creation of the channel / slot allocation request packet, first, the address or ID of the packet transfer destination is registered in the destination address 603. For example, the address or ID of the terminal 300-1d is registered. Next, in the final destination address 604, the address or ID of the gateway 400-1 of the existing system 31 is registered. In the transmission source address 605 and the transmission source address 606, the address or ID of the gateway 400-2 of the new system 32 is registered. A unique packet ID is registered in the packet ID 607. “0” is registered in the slot allocation order flag 608. In the allocation range start slot number 609 and the allocation range end slot number 610, the start point and end point slot numbers calculated in step 701 are registered. In the traffic ID 611, an ID indicating a traffic type of a packet to be transmitted after assignment of a communication channel and a slot is registered. Then, the slot / channel management table of the gateway 400-2 of the new system 32 is registered in the slot / channel management table 612. At this time, as described above, only the slot / channel management table in the range designated by the start slot number 609 of the allocation range and the end slot number 610 of the allocation range may be registered. When this channel / slot allocation request packet is created, the packet is transmitted and the process proceeds to step 703.

  In step 703, the communication channel / slot management unit 306 of the terminal or gateway that has received the channel / slot allocation request packet refers to the transmission source of the packet and its own channel / slot management table to determine the requested slot range. It is a process which extracts an empty channel and an empty slot. In this process, a communication channel and slot that can be secured are extracted from the transmission source of the channel / slot allocation request packet to the receiving terminal or gateway of the packet. A specific extraction method will be described later with reference to FIG. When this process ends, the process proceeds to step 704.

  Step 704 is a process of determining whether or not there is an empty channel / empty slot within the requested slot range as a result of the process of step 703. As a result of the determination, if an empty channel / slot exists (YES), the process proceeds to step 705. If not (NO), the process proceeds to step 707.

  Step 705 is a process of securing the one with the earliest slot number from the empty channels and empty slots in the requested slot range. Specifically, the communication channel / slot management unit 306 of the terminal or gateway that has received the channel / slot allocation request packet confirms that “0” is registered in the slot allocation order flag 608 of the packet, and It is determined that it is necessary to secure the one with the earliest slot number from the empty channels and empty slots in the requested slot range. If a slot with this number can be secured in a plurality of channels, one of the communication channels is selected. What is secured here is a communication channel and a slot for transferring the packet from the transmission source of the channel / slot allocation request packet to the receiving terminal or gateway of the packet. When this process ends, the process proceeds to step 706.

  Step 706 is processing to notify the transmission source of the channel / slot allocation request packet of the communication channel and slot secured in step 705, and both the transmission source and itself update the channel / slot management table. Specifically, “1” is registered in the communication channel and slot portion secured in step 705 in the channel / slot management table. When this process ends, the process proceeds to step 708.

  Step 707 is a process of notifying the gateway 400-2 of the new system 42 that allocation is not possible when there is no empty channel / slot within the requested slot range as a result of the process of step 703. . This notification is transmitted to the gateway of the new system by relaying some terminals on the route from the gateway of the new system to the gateway 400-1 of the existing system 31, and among the terminals that relayed this notification, the step For the terminal whose channel / slot management table has been updated in 706, the portion where “1” is registered in step 706 is returned to “0”, and the reserved communication channel and slot are released. The same applies to the gateway of the new system that has received this notification, and the flowchart of FIG. 7 ends after this processing. At this time, the gateway of the new system may change the packet transfer destination as necessary, and try to allocate a communication channel and slot to another path.

  Step 708 is a process for determining whether or not it is the gateway 400-1 of the existing system 31 that has received the channel / slot allocation request packet. If it is the gateway of the existing system (YES), the assignment of the communication channel and the slot for transferring the packet from the gateway 400-2 of the new system 32 to the gateway of the existing system is completed. Proceed to On the other hand, if it is not the gateway of the existing system (NO), since the allocation of the communication channel and the slot is not completed, the process proceeds to step 709.

  Step 709 is processing in which the terminal that has received the channel / slot allocation request packet updates the packet and transmits it to the next transfer destination. Specifically, the destination address 603 in the channel / slot allocation request packet is updated to the transfer destination address or ID stored in the path management unit 305. The source address 605 is updated to its own address or ID. Also, the start slot number 609 of the allocation range is updated to a value obtained by adding 1 to the slot number secured in step 705. The slot / channel management table 612 of the packet is updated to its own slot / channel management table. The other fields are not updated. However, if there are additional fields in the channel / slot allocation request packet in addition to the registered fields, these may be updated as appropriate. Thereafter, the updated channel / slot allocation request packet is transmitted to the next transfer destination, and the process returns to step 703.

  Step 710 is processing to notify the gateway of the new system from the gateway of the existing system that the assignment of communication channels and slots for transferring packets from the gateway of the new system to the gateway of the existing system has been completed. With this processing, a series of communication channel and slot allocation control operations are completed.

  When the channel / slot management table is updated in step 706, it is necessary to notify the neighboring terminal that a new communication channel and slot have been reserved. This notification is performed at the timing of step 706. However, it may be after receiving the assignment completion notification transmitted in step 710.

Next, with reference to FIG. 8, the processing of step 703 in FIG. 7, that is, the processing of extracting empty channels and empty slots will be described.
Step 801 is processing in which the terminal or gateway that has received the channel / slot allocation request packet uses the variable i as the starting slot number of the allocation range. After this processing, the process proceeds to step 802.

  Step 802 compares the channel / slot management table of the transmission source obtained in the received channel / slot allocation request packet with the channel / slot management table of its own (the terminal or gateway that received the allocation request), and at least one of them The process determines whether “1” is registered in the i-th slot of any channel. As a result of the determination, if “1” is registered (YES), the process proceeds to step 803, and if not registered (NO), the process proceeds to step 804.

  Step 803 is a process for determining that the i-th slot is unusable in all channels, that is, the i-th slot is empty. As described above, unless a special mechanism for simultaneous transmission and reception is provided in the terminal and the gateway, if “1” is assigned to a slot, the slot cannot be used. This determination will be made. However, this does not apply when a mechanism that enables simultaneous transmission and reception is provided. After this processing, the process proceeds to step 806.

  Step 804 compares the channel / slot management table of the transmission source obtained in the received channel / slot allocation request packet with the channel / slot management table of its own, and at least one of the i-th slot of any channel Is a process for determining whether or not “2” is registered. As a result of the determination, if “2” is registered (YES), the process proceeds to step 805, and if not registered (NO), the process proceeds to step 806.

  Step 805 is processing for determining that the i-th slot is unusable in the communication channel in which “2” is confirmed to be registered in step 804. As a result of the determination, if “2” is registered, it is determined that a neighboring terminal existing within a range that causes interference with the transmission source of the channel / slot allocation request packet or itself performs communication using the channel and the slot. It cannot be used because it is shown. After this processing, the process proceeds to step 806.

  Step 806 is processing for determining whether or not the i-th slot matches the end slot number of the allocation range. As a result of the determination, if they match (YES), the flowchart of FIG. 8 is terminated, and if they do not match (NO), the process proceeds to step 807. Step 807 is a process of adding 1 to i, and returns to step 802 after this process.

  Through the process shown in FIG. 8, communication channels and slots that have not been determined to be unusable are extracted as empty channels and empty slots. That is, it is possible to determine that any of these empty channels / slots can be used when the transmission source of the channel / slot allocation request packet is transferred to the own terminal or the own gateway.

  FIG. 9 shows an example of a channel / slot management table and an extraction result of empty channels / slots. Here, it is assumed that a communication channel and a slot for transferring a packet from the gateway 400-2 of the new system 32 to the gateway 400-1 of the existing system 31 are allocated in the range of slots S1 to S10. Here, 500A to 500D show examples of channel / slot management tables in the range of slots S1 to S10 held by the gateway 400-1, the terminal 300-1a, the terminal 300-1d, and the gateway 400-2.

  Based on the channel / slot management table of 500A and 500B, the result of extracting empty channels / slots that can be used for packet transfer from the terminal 300-1a to the gateway 400-1 according to the processing of FIG. 8 is shown in 900A. In 900A, a communication channel and a slot registered with a cross are determined to be unusable, and a portion where nothing is registered is an empty channel / slot.

  Similarly, 900B and 900C show the results of empty channels and empty slots extracted based on the channel and slot management tables of 500B and 500C and the channel and slot management tables of 500C and 500D, respectively.

  An operation example of communication channel and slot allocation according to the first embodiment will be described with reference to the sequence diagram of FIG. In this operation example, communication channels and slots for transferring packets from the gateway 400-2 of the new system 32 to the gateway 400-1 of the existing system 31 in the communication network system of FIG. Assume to assign.

  First, the gateway 400-2 calculates a slot range for which allocation is requested in step 1001. Thereafter, in step 1002, a channel / slot allocation request packet is created and transmitted to the terminal 300-1d as the next transfer destination.

  Next, when the terminal 300-1d receives the channel / slot allocation request packet in step 1003, the terminal 300-1d extracts an empty channel / slot in step 1004, and selects the one having the earliest slot number in the range of S1 to S10. Secure. Specifically, 900C in FIG. 9 is the result of the empty channel / empty slot extracted, and the earliest slot (C2, S1) is secured. Thereafter, in step 1005, the gateway 400-2 is notified that (C2, S1) has been secured for packet transfer from the gateway 400-2 to the terminal 300-1d, and in step 1006, the channel slot of the terminal 300-1d Update the management table. When the gateway 400-2 receives the notification at step 1007, it updates its channel / slot management table at step 1008. The terminal 300-1d updates the channel / slot allocation request packet in step 1009 and transmits it to the terminal 300-1a. At this time, since terminal 300-1d has secured (C2, S1), the slot to be allocated is updated to S2 to S10.

  Next, when the terminal 300-1a receives the channel / slot allocation request packet in step 1010, the terminal 300-1a extracts an empty channel / slot in step 1011 and selects the one having the earliest slot number in the range of S2 to S10. Secure. Specifically, 900B in FIG. 9 is the result of the empty channel / empty slot extracted, and S3 which is the earliest slot is secured. Here, either (C1, S3) or (C2, S3) can be selected, but (C1, S3) is secured this time. Thereafter, in step 1012, the terminal 300-1d is notified that (C1, S3) has been secured for packet transfer from the terminal 300-1d to the terminal 300-1a, and in step 1013 the channel of the terminal 300-1a -Update the slot management table. Also, when the terminal 300-1d receives the notification in step 1014, it updates its own channel / slot management table in step 1015. The terminal 300-1a then updates the channel / slot allocation request packet in step 1016 and transmits it to the gateway 400-1. At this time, since the terminal 300-1a has secured (C1, S3), the slot that becomes the allocation range is updated to S4 to S10.

  Upon receiving the channel / slot allocation request packet in step 1017, the gateway 400-1 extracts an empty channel / slot in step 1018, and secures the one with the earliest slot number in the range of S4 to S10. Specifically, 900A in FIG. 9 is the result of the empty channel / empty slot extracted, and S5 which is the earliest slot is secured. (Slot S2 is also vacant, but is excluded because the slot allocation target range is S4 to S10.) Here, either (C1, S5) or (C2, S5) can be selected. This time, secure (C1, S5). Thereafter, in step 1019, the terminal 300-1a is notified that (C1, S5) has been secured for packet transfer from the terminal 300-1a to the gateway 400-1, and in step 1020 the channel of the gateway 400-1 -Update the slot management table. Also, when the terminal 300-1a receives the notification in step 1021, it updates its own channel / slot management table in step 1022.

  In step 1023, the gateway 400-1 creates a notification packet indicating that the communication channel and slot allocation within the requested range has been completed, and transmits the notification packet to the terminal 300-1a with the gateway 400-2 as the final destination. To do. Upon receiving the channel / slot allocation completion notification in step 1024, the terminal 300-1a transfers it to the terminal 300-1d. Similarly, upon receiving the channel / slot assignment completion notification in step 1025, the terminal 300-1d transfers the notification to the gateway 400-2. When gateway 400-2 receives the channel / slot allocation completion notification in step 1026, the control relating to the communication channel and slot allocation is completed.

  Thereafter, the packet related to the new system 32 received by the gateway 400-2 is transferred to the gateway 400-1 using the communication channels and slots secured through the sequence of FIG. 10, and finally the application server 202 of the system 32. Sent to. In the sequence of FIG. 10, the registration of the process for notifying the neighboring terminals of the communication channel and slot reservation is omitted, but this process is the timing when the own channel / slot management table is updated, or the channel -It can be performed at any timing when the slot allocation completion notification is received.

  As described above, according to the first embodiment, it is possible to perform communication channel and slot allocation control by the terminal existing on the route from the gateway of the new system 32 to the gateway of the existing system 31 and the autonomous distributed control of the gateway. Such a configuration or control operation eliminates the need to change the schedule of terminals belonging to the existing system. In addition, the terminal and gateway on the route from the gateway of the new system to the gateway of the existing system secure the new channel and slot from the empty channel / slot without interfering with the communication of the existing system, Packets related to the new system can be transmitted to the host application server.

  Also, by defining the slot allocation order according to the traffic load relationship between the existing system and the new system, it is possible to effectively use the bandwidth according to the traffic characteristics. In other words, when the traffic load of the existing system is lower than the traffic load of the new system, the allowable delay of the packet is ensured by securing the slot numbers in order from the empty channel / slot slot within the time X range. The packet can be delivered to the upper application server with a delay time as short as possible.

  The first embodiment is an example in which the traffic load of the existing system is lower than the traffic load of the new system, whereas the second embodiment is a case in which the traffic load of the existing system is higher than the traffic load of the new system. It is an example. In this case, from the viewpoint of reducing bandwidth consumption by communication of the new system, it is desirable to accumulate packets for as long a time as possible in the gateway of the new system, combine more packets into one, and transmit them together. In other words, in the second embodiment, the slots within the range within the time X are secured in order from the latest. Also in the second embodiment, communication channel and slot allocation are realized by autonomous distributed control between the gateway and the terminal. A communication channel and slot allocation method according to the second embodiment and an operation example thereof will be described with reference to FIGS. 11 and 12.

  The configuration of the communication network system according to the second embodiment (FIG. 2), the hardware configuration of the terminal and the gateway (FIGS. 3 and 4), the configuration of the channel / slot management table (FIG. 5), the communication channel and the slot allocation The packet format (FIG. 6) used and the empty channel / slot extraction method (FIG. 8) are the same as in the first embodiment.

The communication channel and slot allocation control according to the second embodiment will be described with reference to FIG.
In order to transmit the packet of the new system 32 to the application server via the FAN of the existing system 31, the communication channel and the slot are allocated in advance according to the process of FIG. In the communication channel and slot allocation control according to the second embodiment, in order to secure the slots in order from the slowest possible slot within the time X range, the existing system among the links on the path from the gateway of the new system to the gateway of the existing system. The communication channel and slot for transfer are secured in order from the link closest to the gateway.

  In FIG. 11, step 1101 is a process in which the gateway of the new system calculates the slot range that needs to be allocated in order to transmit the packet received from the terminal connected to the subordinate system to the application server 202 within the allowable delay time. It is. The calculation method is the same as step 701 in FIG. After this processing, the process proceeds to step 1102.

  In step 1102, the gateway of the new system creates a channel / slot allocation request packet in accordance with the packet format of FIG. 6, and transfers it to the transfer destination (the parent terminal when the topology is a tree structure) stored in the route management unit 305 of the gateway 400. On the other hand, it is a process of transmitting the created channel / slot allocation request packet. This process is the same as step 702 in FIG. 7 except that “1” is registered in the field of the slot allocation order flag 608 when creating the channel / slot allocation request packet. After this processing, the process proceeds to step 1103.

  Step 1103 is a process for determining whether or not the channel / slot allocation request packet transmitted in step 1102 or step 1104 described later is the gateway of the existing system. As a result of the determination, if it is a gateway of the existing system (YES), the process proceeds to step 1105, and if it is not the gateway of the existing system (NO), the process proceeds to step 1104.

  Step 1104 is a process in which the terminal that receives the channel / slot allocation request packet updates the packet and transmits it to the next transfer destination. Specifically, in the channel / slot allocation request packet, the destination address 603 is updated to the transfer destination address or ID stored in the route management unit 305 of the terminal 300. The source address 605 is updated to its own address or ID. The slot / channel management table 612 is updated to its own slot / channel management table. The other fields are not updated. However, if there are fields added in addition to the registered fields in FIG. 6, these may be updated as appropriate. Thereafter, the updated channel / slot allocation request packet is transmitted to the next transfer destination, and the processing returns to step 1103.

  In step 1105, the gateway that has received the channel / slot allocation request packet refers to the transmission source of the packet and its own channel / slot management table, and extracts an empty channel / slot within the requested slot range. It is processing. Extraction of empty channels and empty slots is performed according to the flowchart of FIG. When this process ends, the process proceeds to step 1106.

  Step 1106 is a process for determining whether or not an empty channel / slot exists within the requested slot range as a result of the process of step 1105. As a result of the determination, if an empty channel / slot exists (YES), the process proceeds to step 1107, whereas if it does not exist (NO), the process proceeds to step 1109.

  Step 1107 is a process of securing the one with the slowest slot number from the empty channels and empty slots in the requested slot range. Specifically, the terminal or gateway that has received the channel / slot allocation request packet refers to the slot allocation order flag 608 of the packet and confirms that “1” is registered, thereby requesting the requested slot. It is determined that it is necessary to secure the slot with the slowest slot number from the empty channels and empty slots within the range. If a slot with this number can be secured in a plurality of channels, one of the communication channels is selected. What is secured here is a communication channel and a slot for transferring the packet from the transmission source of the channel / slot allocation request packet to the receiving terminal or gateway of the packet. When this process ends, the process proceeds to step 1108.

  Step 1108 is a process of notifying the transmission source of the channel / slot allocation request packet of the communication channel and slot secured in step 1107, and both the transmission source and itself update the channel / slot management table. Specifically, “1” is registered in the communication channel and slot portion secured in step 1107 in the channel / slot management table. When this process ends, the process proceeds to step 1110.

  Step 1109 notifies the new system gateway and the existing system gateway that allocation is not possible when there is no empty channel / slot within the requested slot range as a result of the processing of step 1105. It is processing to do. This notification is transmitted by relaying some terminals on the route from the gateway of the new system to the gateway of the existing system. Of the terminals that relayed this notification, the channel / slot management table is updated in step 1108. For the terminal, the part where “1” is registered in step 1108 is returned to “0”, and the reserved communication channel and slot are released. The same applies to the gateway of the existing system that has received this notification, and the series of processing in FIG. 11 ends after this processing. At this time, the gateway of the new system may change the packet transfer destination as necessary, and try to allocate a communication channel and slot to another path.

  Step 1110 is processing for determining whether or not the notification transmitted in Step 1108 is received by the gateway of the new system. If the result of the determination is that the gateway is a new system (YES), the assignment of communication channels and slots for transferring packets from the new system gateway to the existing system gateway has been completed. The process ends. Unlike the first embodiment, since the gateway of the new system receives the notification transmitted in step 1108, it can be determined that a series of communication channels and slot assignments have been completed. There is no need to send an assignment completion notification. However, it may be separately notified to the gateway of the existing system or the terminal on the transfer route that the allocation is completed.

  On the other hand, if it is determined in step 1111 that the notification transmitted in step 1108 is not the gateway of the new system (NO), it is necessary to transfer a packet from the gateway of the new system to the gateway of the existing system. Since allocation of communication channels and slots is incomplete, the process proceeds to step 1111.

  Step 1111 is a process in which the terminal that has received the notification of Step 1108 refers to the transmission source of the channel / slot allocation request packet and refers to its own channel / slot management table to extract an empty channel / slot. In this case, empty channels and empty slots are extracted according to the processing shown in FIG. 8, but the end point slot number of the allocation range is one before the slot number notified in step 1108. For example, when it is notified in step 1108 that the slot number S8 is secured, the end point slot number when extracting the empty channel / empty slot is S7. That is, when an empty channel / empty slot is extracted in step 1111, it is determined in step 806 in FIG. 8 whether the slot number notified in step 1108 is the i-th previous slot number. When the process of step 1111 is completed, the process returns to step 1106.

  When the channel / slot management table is updated in step 1108, it is necessary to notify the neighboring terminal that a new communication channel and slot have been secured. However, the notification may be made at the timing of step 1108. . On the other hand, when the communication channel and slot allocation completion is notified from the gateway of the new system, it may be notified to the neighboring terminal after receiving the allocation completion notification.

  Next, the operation of communication channel and slot allocation according to the second embodiment will be described with reference to FIG. In the following description, it is assumed that communication channels and slots for transferring packets from the gateway 400-2 of the new system 32 to the gateway 400-1 of the existing system 31 are allocated in the range of slots S1 to S10.

First, the gateway 400-2 calculates a slot range for which allocation is requested in step 1201. Thereafter, in step 1202, a channel / slot allocation request packet is created and transmitted to the terminal 300-1d as the next transfer destination.
Next, when the terminal 300-1d receives the channel / slot allocation request packet in step 1203, it updates the packet and transfers it to the terminal 300-1a. Similarly, when the terminal 300-1a receives the channel / slot allocation request packet in step 1204, the terminal 300-1a updates the packet and transfers it to the gateway 400-1.

  Subsequently, when the gateway 400-1 receives the channel / slot allocation request packet in step 1205, in step 1206, the gateway 400-1 refers to the transmission source of the allocation request packet (terminal 300-1a) and its own channel / slot management table. Channels and empty slots are extracted, and the one with the slowest slot number in the range of S1 to S10 is secured. Specifically, 900A in FIG. 9 is the result of the empty channel / empty slot extracted, and the slowest slot (C2, S10) is secured. Thereafter, in step 1207, the terminal 300-1a is notified that (C2, S10) has been secured for packet transfer from the terminal 300-1a to the gateway 400-1, and in step 1208, the channel of the gateway 400-1 Update the slot management table.

  Upon receiving the communication channel and slot reservation notification in step 1209, the terminal 300-1a updates its channel / slot management table in step 1210. Thereafter, in step 1211, the channel (slot allocation request packet) received in step 1204 (terminal 300-1d) is extracted with reference to its own channel / slot management table, and in step 1209, the channel / slot allocation request packet is extracted. The slot number which is the latest slot number in the range from S1 to S9 is secured before the slot number notified of securing. Specifically, 900B in FIG. 9 is the result of the empty channel / empty slot extracted, and S9 which is the slowest slot is secured. Here, either (C1, S9) or (C3, S9) can be selected, but (C1, S9) is secured this time. Thereafter, in step 1212, the terminal 300-1d is notified that (C1, S9) has been secured for packet transfer from the terminal 300-1d to the terminal 300-1a. In step 1213, the channel / slot of the terminal 300-1a is notified. Update the management table.

  Next, upon receiving the communication channel and slot reservation notification in step 1214, the terminal 300-1d updates its channel / slot management table in step 1215. Thereafter, in step 1216, the channel (slot allocation request packet) received in step 1203 (gateway 400-2) and its own channel / slot management table are referenced to extract an empty channel / slot, and in step 1214 The slot number which is the latest slot number in the range from S1 to S8 is secured before the slot number notified of securing. Specifically, 900C in FIG. 9 is the result of the empty channel / empty slot extracted, and S7 which is the slowest slot is secured. (Slot S9 is also vacant, but is excluded because the target range for slot allocation is S1 to S8.) Here, either (C1, S7) or (C3, S7) can be selected, This time, secure (C1, S7). Thereafter, in step 1217, the gateway 400-2 is notified that (C1, S7) has been secured for packet transfer from the gateway 400-2 to the terminal 300-1d, and in step 1218, the channel slot of the terminal 300-1d Update the management table.

  Upon receiving the communication channel and slot reservation notification in step 1219, the gateway 400-2 updates its channel / slot management table in step 1220. When the step 1220 is completed, the control relating to the communication channel and the slot assignment is completed, and the packet relating to the system 32 received by the gateway 400-2 thereafter uses the communication channel and the slot secured through the sequence of FIG. The data is transferred to the gateway 400-1 and finally transmitted to the application server 202 of the system 32. Note that the gateway 400-2 may notify the terminal 300-1d, the terminal 300-1a, and the gateway 400-1 of the completion of channel / slot allocation separately at the timing when the step 1220 is completed. Further, in the sequence of FIG. 12, the description of the process of notifying the neighboring terminal of the communication channel and slot reservation is omitted, but this process is the timing when the own channel / slot management table is updated, or the channel -It may be performed at any timing when the slot allocation completion notification is received.

  As described above, as in the first embodiment, it is possible to eliminate the necessity of changing the schedule of the terminals belonging to the existing system, and further, the packets related to the new system can be transferred to the upper application server without interfering with the communication of the existing system. It becomes possible to deliver. Further, in the second embodiment, when the traffic load of the existing system is higher than the traffic load of the new system, the reservation is performed in the order of the slot number from the free channel / empty slot within the range within the time X, in order of increasing slot number. In order to reduce the amount of bandwidth consumed by communication of the new system, the packets can be accumulated in the gateway of the new system as long as possible while the allowable delay of the packet is satisfied, and a plurality of packets are combined into one. It becomes possible.

  In the first and second embodiments, the route is configured by one route from the gateway of the new system to the gateway of the existing system. However, if the gateway of the new system has multiple routes with respect to the gateway of the existing system, a communication channel and slot allocation request is made for each route, for example, with the shortest delay time among them. You may make it select the path | route which can implement | achieve the packet transfer with respect to the gateway of a system.

  In the first and second embodiments, the description has been made on the assumption that communication channels and slots are allocated for a new system. However, when a terminal belonging to an existing system is newly added, communication for the terminal to perform communication is performed. When assigning channels and slots, the above embodiment can be applied. Specifically, the terminal performs the processing performed by the gateway of the new system in step 701 and step 702 in FIG. 7, and step 1101 and step 1102 in FIG. 11, and the step 707 and step 710 in FIG. This can be realized by replacing the final destination of the notification transmitted in 1109 with the terminal, and replacing the determination criterion regarding the destination in step 1110 of FIG. 11 from the gateway of the new system to the terminal.

  While the first and second embodiments are examples in which communication channel and slot allocation control is performed by autonomous distributed control of a gateway, the third embodiment is a channel / slot management table of a terminal on a communication network system and a gateway. This is an example in which communication channels and slot allocation are realized by centralized control of a management device that manages the communication. When the gateway or terminal can notify the management device of the information in the channel / slot management table every time it is updated, such as in a broadband environment or when the number of terminals is small, centralized control by the management device can be realized. When centralized control is performed by the management device, it is possible to determine whether or not communication channels and slots can be allocated collectively by the management device, and when the gateway of the new system holds multiple paths to the gateway of the existing system The management device calculates the communication channels and slots that can be assigned in each route, so that processing such as notifying the best route to the gateway of the new system becomes possible.

  Hardware configuration (FIGS. 3 and 4) of terminal and gateway according to embodiment 3, configuration of channel / slot management table (FIG. 5), format of communication channel and packet used for slot allocation (FIG. 6), free channel The method for extracting empty slots (FIG. 8) is the same as in the first and second embodiments.

  The communication network system shown in FIG. 13 has the same configuration as that of the communication network system in FIG. 2 except that the management apparatus 1300 is connected to the network. The management apparatus 1300 collects channel / slot management table information of terminals and gateways on the communication network system using wired or wireless communication, and centrally manages these information. Therefore, each terminal and each gateway notify the management apparatus 1300 of its channel / slot management table when the management apparatus 1300 can manage these pieces of information as needed. When the management device 1300 receives the channel / slot allocation request packet, the management device 1300 refers to the channel / slot management table of each terminal and each gateway, extracts a free channel / slot, and assigns a communication channel / slot. Mount.

  Next, communication channel and slot allocation control according to the third embodiment will be described with reference to FIG. Here, when the packet of the new system 32 is transmitted to the application server 202 via the FAN of the existing system 31, communication channels and slots are allocated by the processing of FIG. 14.

  In FIG. 14, Step 1401 is a range of slots that need to be allocated in order for the gateway 400-2 of the new system 32 to transmit a packet received from a terminal connected thereto to the application server 202 within the allowable delay time. Is a process for calculating. The calculation method is the same as step 701 in FIG. After this processing, the process proceeds to step 1402.

In step 1402, the gateway of the new system creates a channel / slot allocation request packet in accordance with the packet format of FIG. 6, and the transfer destination stored in the route management unit 305 of the gateway 400-2 (if the topology is a tree structure, the parent terminal ) To the created channel / slot allocation request packet.
To create a channel / slot allocation request packet, first, the packet transfer destination address or ID is registered in the destination address 603. In the example of FIG. 13, the address or ID of the terminal 300-1d is registered. Next, the address or ID of the management apparatus 1300 is registered in the final destination address 604. In the transmission source address 605 and the transmission source address 606, the address or ID of the gateway 400-2 of the new system 32 is registered. A unique packet ID is registered in the packet ID 607. In the slot allocation order flag 608, “0” is registered when the traffic load of the existing system 31 is lower than the traffic load of the new system 32, and “1” is registered when it is higher. In the allocation range start slot number 609 and the allocation range end slot number 610, the start point and end point slot numbers calculated in step 1401 are registered. In the traffic ID 611, an ID indicating a traffic type of a packet to be transmitted after assignment of a communication channel and a slot is registered. Regarding the slot / channel management table 612, since the information is grasped and managed by the management apparatus 1300, it is not necessary to register the information. When this channel / slot allocation request packet is created, the packet is transmitted, and the process proceeds to Step 1403.

  Step 1403 is a process for determining whether or not the channel / slot allocation request packet transmitted in step 1402 or step 1404 described later is the gateway of the existing system. As a result of the determination, if it is a gateway of the existing system (YES), the process proceeds to step 1405, and if it is not the gateway of the existing system (NO), the process proceeds to step 1404.

  Step 1404 is a process in which the terminal or gateway that has received the channel / slot allocation request packet updates the packet and transmits it to the next transfer destination. Specifically, in the channel / slot allocation request packet, the destination address 603 is updated to the transfer destination address or ID stored in the route management unit 305 of the terminal 300. The source address 605 is updated to its own address or ID. The other fields are not updated. Thereafter, the updated channel / slot allocation request packet is transmitted to the next transfer destination, and the process returns to Step 1403.

  Step 1405 is a process in which the management apparatus 1300 that has received the channel / slot allocation request packet determines whether the value registered in the slot allocation order flag 608 of the allocation request packet is “0”. If the determination result is “0” (YES), the process proceeds to step 1406, and if it is not “0”, that is, “1” (NO), the process proceeds to step 1410.

  Step 1406 is a process in which the management device extracts empty channels and empty slots in order from the link closest to the gateway of the new system in the path from the gateway of the new system to the gateway of the existing system. In the example of FIG. 13, the available space for packet transfer in each link in the order of gateway 400-2 to terminal 300-1d, terminal 300-1d to terminal 300-1a, and terminal 300-1a to gateway 400-1. Extract channels and empty slots. When the extraction for one link is completed, the process proceeds to step 1407. Extraction of empty channels / slots is performed according to the flowchart of FIG. 8, but in steps 802 and 804, determination is made with reference to two channel / slot management tables of the transfer source and transfer destination on the link.

  Step 1407 is a process for determining whether or not there is an empty channel / empty slot within the allocation range as a result of the process of step 1406. As a result of the determination, if an empty channel / slot exists (YES), the process proceeds to step 1408, and if not (NO), the process proceeds to step 1414.

  Step 1408 is a process of securing the one with the earliest slot number from the empty channels / slots within the allocation range. If a slot with the same number can be secured in a plurality of channels, one of the communication channels is selected. When the slot number to be secured is determined, the starting slot number of the allocation range is updated to a value obtained by adding 1 to the secured slot number. When this process ends, the process proceeds to step 1409.

  Step 1409 is processing for determining whether or not assignment of communication channels and slots has been completed in all links on the route from the gateway of the new system to the gateway of the existing system. If completed (YES), the process proceeds to step 1415, and if not completed (NO), the process returns to step 1406.

  Step 1410 is a process in which the management device extracts empty channels and empty slots in order from the link closest to the gateway of the existing system, among the paths from the gateway of the new system to the gateway of the existing system. In the example of FIG. 13, the available space for packet transfer in each link in the order of terminal 300-1a to gateway 400-1, terminal 300-1d to terminal 300-1a, gateway 400-2 to terminal 300-1d. Extract channels and empty slots. When the extraction for one link is completed, the process proceeds to step 1411. The extraction of the empty channel / empty slot is performed according to the flowchart of FIG. 8, but in the same manner as in step 1406, in step 802 and step 804, determination is made by referring to the two channel / slot management tables of the transfer source and transfer destination on the link. I do.

  Step 1412 is a process for determining whether or not there is an empty channel / slot within the allocation range as a result of the process of step 1411. As a result, if it exists (YES), the process proceeds to step 1412. If it does not exist (NO), the process proceeds to step 1414.

  Step 1412 is a process of securing the one with the slowest slot number from the empty channels / slots within the allocation range. If a slot with the same number can be secured in a plurality of channels, one of the communication channels is selected. When the slot number to be secured is determined, the end point slot number of the allocation range is updated to a value obtained by subtracting 1 from the secured slot number. When this process ends, the process proceeds to step 1413.

  Step 1413 is processing for determining whether or not assignment of communication channels and slots has been completed in all links on the route from the gateway of the new system to the gateway of the existing system. If the determination is completed (YES), the process proceeds to step 1415. If the determination is not completed (NO), the process returns to step 1410.

  Step 1414 is a process of notifying that the allocation is impossible to the gateway of the new system when there is no empty channel / slot within the allocation range as a result of the process of Step 1406 or Step 1410. After this processing, the flowchart of FIG. 14 ends.

  Step 1415 is a process of notifying the communication channel and slot secured in Step 1408 and Step 1412 to the gateway of the new system, the gateway of the existing system, and the terminals existing on the routes of both gateways. In addition, the terminal and the gateway that have received this notification update their channel / slot management table for the communication channel and slot that have been notified of the reservation, and notify the neighboring terminals of the update. After this processing, a series of processing ends.

  Next, an operation example of communication channel and slot allocation according to the third embodiment will be described with reference to FIG. In this operation example, it is assumed in FIG. 13 that communication channels and slots for transferring packets from the gateway 400-2 of the new system to the gateway 400-1 of the existing system are allocated in the range of slots S1 to S10. . Further, the case where the traffic load of the existing system is lower than the traffic load of the new system will be described.

  First, the gateway 400-2 calculates a slot range for which allocation is requested in step 1501. Thereafter, in step 1502, a channel / slot allocation request packet is created and transmitted to the terminal 300-1d as the next transfer destination.

  Next, when terminal 300-1d receives the channel / slot allocation request packet in step 1503, it updates the packet and transfers it to terminal 300-1a. Similarly, when the terminal 300-1a receives the channel / slot allocation request packet in step 1504, it updates the packet and transfers it to the gateway 400-1. When the gateway 400-1 also receives the channel / slot allocation request packet in step 1505, it updates the packet and transfers it to the management apparatus 1300.

  Upon receiving the channel / slot allocation request packet in step 1506, the management apparatus 1300 extracts an empty channel / slot for transferring the packet from the gateway 400-2 to the terminal 300-1d in step 1507, and from among these, The slot with the earliest slot number in the range of S1 to S10 is secured. Specifically, 900C in FIG. 9 is the result of the empty channel / empty slot extracted, and the earliest slot (C2, S1) is secured.

  Subsequently, in step 1508, empty channels / slots for transferring packets from the terminal 300-1d to the terminal 300-1a are extracted, and the one with the earliest slot number in the range of S2 to S10 is secured. To do. Specifically, 900B in FIG. 9 is the result of the empty channel / empty slot extracted, and S3 which is the earliest slot is secured. Here, either (C1, S3) or (C2, S3) can be selected, but (C1, S3) is secured this time.

  In step 1509, empty channels and empty slots for transferring packets from the terminal 300-1a to the gateway 400-1 are extracted, and the one with the earliest slot number in the range from S4 to S10 is secured. Specifically, 900A in FIG. 9 shows the result of the empty channel / empty slot extracted, and S5 which is the earliest slot is secured. Here, either (C1, S5) or (C2, S5) can be selected, but (C1, S5) is secured this time. (Slot S2 is also vacant, but is excluded because the target range of slot allocation is S4 to S10.) Thereafter, in step 1510, management device 1300 is gateway 400-2, terminal 300-1d, and terminal 300-1a. The gateway 400-1 is notified of the reserved communication channel and slot.

  Upon receiving the notification of the reserved communication channel and slot in step 1511, the gateway 400-1 transfers the notification to the terminal 300-1a, and updates the channel / slot management table and updates to the neighboring terminal in step 1512. Make a notification.

  When terminal 300-1a receives the notification of the reserved communication channel and slot in step 1513, terminal 300-1a transfers the notification to terminal 300-1d, and updates the channel / slot management table and updates to the neighboring terminal in step 1514. Make a notification. Similarly, when the terminal 300-1d receives the notification of the reserved communication channel and slot in step 1515, the terminal 300-1d transfers the notification to the gateway 400-2, updates the channel / slot management table in step 1516, and the neighboring terminal. Update notification to.

  Finally, upon receiving notification of the reserved communication channel and slot at step 1517, the gateway 400-2 performs update of the channel / slot management table and update notification to neighboring terminals at step 1518. At the end of step 1518, the control relating to the communication channel and slot assignment is completed, and the packet relating to the system 32 received by the gateway 400-2 thereafter uses the communication channel and slot secured through the sequence of FIG. The data is transferred to the gateway 400-1 and finally transmitted to the application server 202 of the system 32.

  As described above, in the third embodiment, when performing communication channel and slot assignment control by centralized control of the management apparatus, the channel / slot management table held by the management apparatus reaches from the gateway of the new system to the gateway of the existing system. An empty channel / slot is extracted from a link on the route, and a communication channel and a slot are secured from that. By controlling in this way, as in the first and second embodiments, the necessity of changing the schedule of the terminals belonging to the existing system is eliminated, and packets related to the new system are transmitted to the upper application without interfering with the communication of the existing system. It can be delivered to the server. Furthermore, by defining the slot allocation order according to the traffic characteristics of the existing system and the new system, the bandwidth corresponding to the traffic characteristics can be effectively utilized even in the case of centralized control in the management apparatus.

  In the third embodiment, the example of the centralized control by the management apparatus has been described. However, when the gateway has a sufficient storage capacity and can manage the channel / slot management table of the terminal on the communication network system and other gateways, Centralized control by a gateway may be performed. In this case, it is possible to reduce the time required for allocation of communication channels and slots as compared with the centralized control by the management apparatus.

Also in the third embodiment, the description has been made assuming that only one path from the gateway of the new system to the gateway of the existing system is constructed. However, as in the first and second embodiments, when the gateway of the new system holds a plurality of routes with respect to the gateway of the existing system, the management device performs communication channel and slot assignment processing in each route, It is possible to select a route that can secure the best communication channel and slot, and notify the gateway of the new system to use the route.
Further, as in the first and second embodiments, the third embodiment can be applied as communication channel and slot allocation when a terminal belonging to an existing system is newly added.

  In the first to third embodiments, when a vacant channel / slot is extracted, if a neighboring terminal existing in a range that interferes with itself or itself has already used a certain communication channel and slot for transmission or reception, It is an example which determines that is unusable. In this case, these slots may be used only partly for the slot width. For example, if each slot width is designed with 50 milliseconds, there may be slots where only the first 30 milliseconds are used to transmit or receive a packet. At this time, when trying to allocate a communication channel and a slot necessary for transferring a packet that can be transmitted or received within 20 milliseconds, the slot that is actually used only for 30 milliseconds is also an empty slot. Can be used as Thus, an example will be described in which empty channels / slots are extracted with finer granularity by referring to the time used for transmission or reception in each slot. In the fourth embodiment, the time length used for transmission or reception in each slot by the channel / slot management table held by the terminal, gateway, and management device on the communication network system described in the first to third embodiments. Manage.

  Configuration of communication network system according to Embodiment 4 (FIGS. 2 and 13), hardware configuration of terminals and gateways (FIGS. 3 and 4), format of packets used for communication channel and slot allocation (FIG. 6), communication Channel and slot allocation control (FIGS. 7, 11, and 14) is the same as in the first to third embodiments.

The channel / slot management table and the usage time management table according to the fourth embodiment will be described with reference to FIG.
As in FIG. 5, the channel / slot management table 1600A indicates “0” for each channel / slot, which is a channel / slot that is not used by itself or a neighboring terminal or gateway existing in a range where it interferes with itself. “1” is registered in the channel / slot used for transmission or reception by itself, and “2” is registered in the channel / slot used for transmission by a neighboring terminal or gateway existing in the range of interference with itself. However, in the fourth embodiment, there is a case where a plurality of packets are transmitted and received within one slot. Therefore, the channel / slot used by itself for transmission or reception is managed together with the traffic type of the packet transmitted / received in each slot. For example, in the illustrated management table 1600A, packet type information is stored in parentheses. Thereby, in the example shown in the figure, it can be understood that (C2, S1) is used for type 1 packets and (C1, S3) is used for type 1 and type 2 packets. Here, the traffic type is the same as the type information stored in the traffic ID 611 in FIG.

  Next, the usage time management table 1600B is similarly held by the terminal and the gateway or the management apparatus. The usage time management table is a table for managing the time used for transmission / reception for each channel / slot in which “1” or “2” is registered in the channel / slot management table 1600A. Is stored. That is, in the example shown in the figure, it can be seen that 30 milliseconds are used for (C2, S1) and 45 milliseconds are used for transmission / reception in (C1, S3). Here, the unit of time to be described is assumed to be milliseconds, but the unit may be microseconds or seconds according to the throughput or packet size of the network. As described above, the usage time management table 1600B also manages how much time is used for transmission / reception by neighboring terminals and gateways existing in a range where they interfere with each other in each slot. Therefore, in order to realize this, when a channel / slot is newly secured in the first to third embodiments, the channel / slot information is notified to neighboring terminals and gateways. In the fourth embodiment, the usage time is also notified. Shall.

Next, with reference to FIG. 17, the empty channel / empty slot extraction operation according to the fourth embodiment will be described.
First, Step 1701 is processing for setting the variable i as the start slot number of the allocation range, as in Step 801 of FIG. After this processing, the process proceeds to step 1702.
As in step 802 of FIG. 8, step 1702 also compares two channel / slot management tables and determines whether “1” is registered in the i-th slot of any channel in at least one of them. It is. If “1” is registered as a result of the determination (YES), the process proceeds to step 1703, and if not registered (NO), the process proceeds to step 1705.

  In step 1703, a free time for transmitting or receiving a desired packet is compared with the time length already known to be used for transmission or reception in the slot in which “1” is registered in step 1702. This is a process for determining that it does not remain. Specifically, the usage time of the corresponding slot is confirmed with reference to the usage time management table. At this time, the time obtained by subtracting the usage time from the slot width is the slot free time. For example, when the slot width is 50 milliseconds and the value registered in the usage time management table is 30 milliseconds, the free time of the slot is determined to be 20 milliseconds. As a result of the determination, if there is no free time remaining (YES), the process proceeds to step 1704, and if there is remaining free time (NO), the process proceeds to step 1705.

  Step 1704 is processing for determining that the i-th slot is unusable in all channels, that is, there is no vacancy in the i-th slot, as in step 803 of FIG. As described above, unless a special mechanism for transmitting and receiving at the same time is provided in the terminal and the gateway, if “1” is assigned to a slot, the slot cannot be used. Judgment will be made. After this processing, the process proceeds to step 1708.

  Step 1705 is a process of comparing two channel / slot management tables and determining whether “2” is registered in the i-th slot of any channel at least on one side, as in step 804 of FIG. is there. If the determination result “2” is registered (YES), the process proceeds to step 1706, and if not registered (NO), the process proceeds to step 1708.

  In step 1706, in the slot in which “2” is registered in step 1705, a free time for transmitting or receiving a desired packet is already obtained for a time length already known to be used for transmission or reception. This is a process for determining that it does not remain. Here, as in step 1703, the available time of the corresponding slot is calculated by referring to the usage time management table. As a result of the determination, if there is no free time remaining (YES), the process proceeds to step 1707, and if there is free time remaining (NO), the process proceeds to step 1708.

  Step 1704 confirms that “2” is registered in Step 1705 and confirms that there is no remaining time for transmitting or receiving a desired packet in Step 1706. This is a process for determining that the slot is unavailable. After this processing, the process proceeds to step 1708.

Step 1708 is a process for determining whether or not the i-th slot matches the end slot number of the allocation range, similar to step 806 in FIG. If the determination results in a match (YES), the flowchart of FIG. 17 is terminated. If the determination does not match (NO), the process proceeds to step 1709.
Step 1709 is a process of adding 1 to i, similar to step 807 of FIG. 8, and returns to step 1702 after this process.

  Through the above processing, communication channels and slots that have not been determined to be unusable are extracted as empty channels and empty slots. In this way, by referring to the time used for transmission or reception in each slot, it is determined whether or not there is a free time necessary for transmitting or receiving a desired packet. It can be used more effectively.

31, 32: System 201, 202: Application server 300: Terminal 304: Communication processing unit 305: Path management unit 306: Communication channel / slot management unit 400: Gateway 500: Channel / slot management table 501: Communication channel 502: Slot 600 : Channel / slot allocation request packet 601: Header 602: Payload 1300: Management device

Claims (9)

A communication device that assigns a communication channel and a slot to transfer a packet from another communication device on the transfer path,
A channel / slot management table for managing communication channels and slots used by the own communication device and other communication devices existing in the interference range;
When there is a request for allocation of a communication channel and slot from another communication device at the time of transfer of the packet, the channel / slot management table of the own communication device and the channel of the adjacent transfer source communication device on the transfer path An extraction means for referring to the slot management table and extracting available channels and available slots for packet transfer;
Allocating means for allocating a communication channel and a slot selected from an empty channel and an empty slot according to an allowable delay time and traffic characteristics of the packet;
Means for calculating a slot range that needs to be allocated to satisfy an allowable delay of a packet when a communication channel and a slot for packet transfer are needed;
Means for determining whether to allocate from an early slot or a later slot within the slot range based on traffic characteristics;
Means for requesting allocation of a communication channel and a slot for transferring the packet to another communication device existing on the transfer path;
A communication apparatus comprising: Upon receiving a communication channel and slot allocation request from the allocating means and newly allocating a communication channel and slot from among empty channels and empty slots, update the channel and slot management table of the own communication device, Notifying other communication devices existing in the interference range that the communication channel and slot have been newly allocated,
The communication apparatus according to claim 1. When receiving a notification that a communication channel and a slot are newly allocated from another communication device existing in the interference range, update the channel / slot management table of the communication device.
The communication apparatus according to claim 1. The channel / slot management table manages the length of time used for transmission or reception in each slot;
Referring to the channel / slot management table, when extracting available channels / slots that can be used for packet transfer, even if a slot has been used by any communication device, other packets are communicated. If there is remaining free time, assign the slot,
The communication apparatus according to any one of claims 1 to 3 . The packet includes a destination address, a final destination address, a source address, a source address, a header including a packet ID,
It has a payload including information on the channel / slot management table of the communication device as a transmission source,
The extraction means refers to information relating to the channel / slot management table of the communication apparatus that is a transmission source of the packet, and extracts an empty channel / empty slot within a requested slot range. 4. The communication device according to any one of items 4 . The header of the packet specifies a flag that specifies whether to secure in order from the earliest one of the empty slots, or in order from the latest one, and
The communication apparatus according to claim 5 , comprising a communication channel and a slot number that is a start point and an end point indicating a slot range in which slot allocation is desired. A first system including at least a first communication device that can be connected to an application server via a network, and at least a second communication device that can be connected to a communication device included in the first system In a communication network system having a second system, a communication device for transferring a packet transferred from the second communication device of the second system to the first communication device of the first system A method for assigning communication channels and slots,
Managing communication channels and slots used by the first communication device, the second communication device, and other communication devices existing in the interference range using a channel / slot management table;
The second communication device of the second system is selected from the empty channels and empty slots of the communication devices on the path to the first communication device and the first communication device of the first system. Sending an allocation request for requesting the first communication device to allocate a communication channel and slot for transferring a packet within an allowable delay time;
The communication device that has received the allocation request can use it for packet transfer by referring to the channel / slot management table of its own communication device and the channel / slot management table of the adjacent transfer source communication device on the path. Extracting a free channel / slot,
Possess assigning a communication channel and slots selected from among the idle channel idle slot in response to the allowable delay time and the traffic characteristics of the packet, and
When the traffic load of the first system is lower than the traffic load of the second system (first case), the second communication device of the second system sends the second system traffic to the first system. Securing a communication channel and a slot for transfer within a range that falls within an allowable delay time in order from a link close to the second communication device of the second system among links on a route to one communication device;
When the traffic load of the first system is higher than the traffic load of the second system (second case), the second communication device of the second system sends the second traffic of the first system. A communication channel and a slot for transfer are secured within a range that falls within an allowable delay time in order from a link close to the first communication device of the first system among links on a route to one communication device.
A method for assigning communication channels and slots. In the first case, in order from the empty slot / empty slot managed by the channel / slot management table in the order of the earliest slot number,
In the second case, the channel number is allocated in order from the slowest slot number among the empty channels and empty slots managed by the channel and slot management table.
The communication channel and slot allocation method according to claim 7 . The communication network system includes a management device that centrally manages the channel / slot management table of the communication device included in the first system and the second system,
The communication device that has received the allocation request transfers the allocation request to the management device,
The management device refers to a channel / slot management table of a transfer source communication device adjacent to a communication device on the path, and extracts a free channel / empty slot that can be used for packet transfer.
The communication channel and slot allocation method according to claim 7 .

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