JP5649458B2 - Access control apparatus and program - Google Patents

Description

  The present invention relates to an access control apparatus and program, and, for example, to a random delay generation method characterized in that, in an ONU that supports multiple LLIDs, it is possible to avoid collision of Register Request frames in the discovery process and to shorten the time until communication channel establishment. It can be applied.

  In recent years, an access network called FTTH (Fiber To The Home) using an optical fiber as a transmission path has been widespread for the purpose of providing high-speed and broadband broadband services to general private homes. An optical access system called PON (Passive Optical Network) is widely used.

  As shown in FIG. 4, the PON system 6 includes one optical line terminal unit (OLT) 2 and a plurality of optical line terminal units (ONUs) 5 (5-). 1 to 5-n (n is a natural number)) is a configuration in which one optical cable 4 is branched and connected in a one-to-many manner using an optical passive element called an optical splitter (for example, an optical coupler or the like) 3. By sharing the optical fiber 4 and the transmission apparatus (not shown) among a plurality of subscribers, it is possible to provide an FTTH service economically.

  In the PON system 6, a WDM (Wavelength Division Multiplexing) method using different wavelengths is generally used for communication from the OLT 2 to the ONU 5 and communication from the ONU 5 to the OLT 2. In addition, since a single fiber 4 is shared by a plurality of ONUs 5-1 to 5-n, communication from the ONU 5 to the OLT 2 uses a TDMA (Time Division Multiple Access) method to avoid collision of signals from each ONU 5. doing.

  As an access network using a PON system, there is a network called GE-PON (Gigabit Ethernet PON) standardized as IEEE Std 802.3ah using Gigabit Ethernet as a protocol.

  GE-PON defines a control function called Multi-point MAC Control (MPCP) for the above-mentioned access control by TDMA. By transmitting and receiving a control frame called MAC Control frame between OLT 2 and ONU 5 MPCP control is realized.

  In MPCP, prior to communication between the OLT 2 and the ONU 5, a communication path is established between the OLT 2 and the ONU 5 by a procedure called a discovery process. In the discovery process, the discovery control MAC control frame is transmitted and received between the OLT 2 and the ONU 5 to establish a communication path between the OLT 2 and the ONU 5.

  First, a MAC Control frame called Discovery Gate is transmitted from OLT 2 to all ONUs 5-1 to 5-n by broadcast. When the ONU 5 whose communication path is not established receives the Discovery Gate frame, the ONU 5 transmits a MAC Control control frame called Register Request to the OLT 2 to make a request for establishment of the communication path.

  Generally, these operations are constituted by functional blocks as shown in FIG. FIG. 5 is a functional block diagram illustrating functions of the discovery process processing unit 51 included in a certain ONU 5.

  The Discovery Gate frame received by the ONU 5 is received and processed by the Discovery Gate reception processing unit 511, and the Start Time information and the Length information transmitted by the Discovery Gate frame are notified to the random delay & Start Time generation unit 512.

  The random delay & StartTime generation unit 512 generates a random delay time within a range that does not exceed the Length information value, and notifies the Register Request transmission processing unit 513 of StartTime information in which the delay time is added to the StartTime value.

  The Register Request transmission processing unit 513 transmits a Register Request frame to the OLT 2 when the transmission time reaches StartTime. In the Discovery Gate frame, there is an information area called TimeStamp for transmitting the time counter value in OLT 2 to ONU 5. Each ONU 5 performs time synchronization with the OLT 2 by loading the Time Stamp value in the received Discovery Gate frame into its own time counter value. When the Register Request frame transmission timing from each ONU 5 becomes the same, and when the Register Request frame collides and cannot be received by the OLT 2, the discovery process is performed again and repeated until successful.

  By such control, as shown in FIG. 6, even when the ONUs 5-1 to 5-3 are at the same distance from the OLT 2, the Register Request frame transmissions from the respective ONUs 5-1 to 5-3 always collide. To prevent the discovery process from failing forever.

  In the discovery process, identification information called LLID (Logical Link ID) is uniquely assigned to each ONU 5. The frames transmitted from the OLT 2 and the ONU 5 are given this LLID, and are used for identifying the frame transmission destination and the transmission source ONU 5. That is, when the destination of the frame is from OLT2 to ONU5, ONU5 checks whether the LLID value in the frame is the same as the LLID assigned to it in advance by the discovery process of OLT2, and receives the frame. When the frame destination is ONT5 to OLT2, the OLT2 compares the LLID value in the frame with the contents of the LLID list registered in the OLT2, and determines whether to receive the frame. doing.

  In general, the LLID is configured with one LLID per ONU, but there is a plurality of LLID processing apparatuses configured with a plurality of LLIDs per ONU as disclosed in Patent Document 1.

The multiple LLID processing apparatus is characterized in that a layer lower than the RS layer is shared, and more layers are individually provided for each LLID. Therefore, the MPCP layer is also individually provided for each LLID, and as shown in FIG. 7, the discovery process processing unit 51 is also provided for each LLID. In the discovery process, each reception of the Discovery Gate frame is performed. A Register Request frame is transmitted for each LLID.

JP 2007-74256 A

  In the multiple LLID processing devices as described above, a Register Request frame is transmitted at a StartTime with a random delay added to each LLID. However, since a delay is randomly generated, there is a case where a Register Request frame collides with a certain probability. is there. When a collision occurs, the discovery process at that time of the corresponding LLID fails and re-execution is performed in the next discovery process, so that it takes time to establish a communication path.

  Also, when realizing a plurality of LLID processing devices, it is conceivable that functional parts that are also layers above the RS layer can be made more efficient by sharing a circuit, and at that time, there is a collision of Register Request frame transmission of each LLID. Occurrence may cause a failure in the function of the common circuit portion.

  Therefore, the present invention has been made to cope with the above situation, and in a user terminal unit (ONU) corresponding to access control using a plurality of identification information (LLID), a communication path establishment request frame related to access control. To provide an access control device and a program capable of avoiding a collision of (for example, a Register Request frame) and shortening a time until establishing a communication path, and avoiding a functional failure of a common circuit portion of a user-side terminal device With the goal.

In order to solve such a problem, an access control device according to a first aspect of the present invention is provided in a user-side termination device facing a station-side termination device that constitutes an optical communication network, and is connected to the station-side termination device. In the access control device that transmits and receives a control frame related to access control with the station-side terminal device and performs synchronization with the station-side terminal device for each identification information using a plurality of identification information assigned to the communication of (1) control frame receiving means for receiving a control frame related to access control from the station-side terminal device; and (2) one random delay value for each user-side terminal device when a communication path search frame is received by the control frame receiving means. (3) The frame transmission time necessary for transmission of the communication path establishment request frame is sequentially added to the generated random delay value. Periodically, a frame transmission timing generating means for determining a transmission timing of each communication path establishment request frame, (4) based on each transmit timing determined for each identification information by the frame transmission timing generating unit, the communication path establishment request Control frame transmission means for transmitting the frame to the station- side terminal device.

An access control program according to a second aspect of the present invention is provided in a user-side terminal device facing a station-side terminal device that constitutes an optical communication network, and includes a plurality of communication programs assigned to the station-side terminal device. In the access control program that uses the identification information to transmit / receive a control frame related to access control to / from the station-side terminator and synchronizes with the station-side terminator for each identification information, Control frame receiving means for receiving a control frame related to access control from a terminal device; (2) random delay generation for generating one random delay value for the user side terminal device when a communication path search frame is received by the control frame receiving means; (3) The frame transmission time necessary for transmission of the communication path establishment request frame is sequentially added to the generated random delay value. Can, frame transmission timing generating means for determining a transmission timing of each communication path establishment request frame, the (4) based on each transmit timing determined for each identification information by the frame transmission timing generating unit, the communication path establishment request frame to function as a control frame transmitting means for transmitting to the station side terminating device and said Rukoto.

  According to the present invention, it is possible to avoid collision of communication channel establishment request frames related to access control and shorten the time until communication channel establishment, and to avoid a functional failure of the common circuit portion of the user side termination device. .

It is a functional block diagram which shows the structure of the discovery process of ONU which concerns on embodiment. It is explanatory drawing explaining the random delay production | generation method which concerns on embodiment. It is explanatory drawing which shows the Register Request frame transmission time relationship which concerns on embodiment. It is a block diagram which shows the structure of a PON system. It is a functional block diagram which shows the structure of the discovery process of the conventional ONU. It is explanatory drawing which shows the conventional Register Request frame transmission time relationship. It is a functional block diagram which shows the discovery process of the conventional ONU corresponding to multiple LLIDs.

(A) Embodiment Hereinafter, an embodiment of an access control apparatus and program of the present invention will be described with reference to the drawings.

(A-1) Configuration of Embodiment In the following embodiment, one OLT (station-side terminal device) and a plurality of ONUs (subscriber-side terminal devices) are branched using an optical splitter. An example in which the present invention is applied to each ONU of a PON system that is connected in a one-to-many manner is illustrated. Note that the configuration of the PON system is the same as that of the prior art, and will be described with reference to FIG.

  The PON system 6 can apply GE-PON, for example, and exemplifies a case where access control between the OLT 2 and the ONU is performed by MPCP control.

  FIG. 1 is a functional block diagram of a discovery process of the ONU 1 according to the embodiment. As shown in FIG. 1, the ONU 1 includes a discovery process processing unit 11 and a MUX / DEMUX unit 12 as a discovery process function.

  Although not shown in FIG. 1, the ONU 1 includes functional units that function as a PMD (Physical Medium Dependent) layer, a PMA (Physical Medium Attachment) layer, an FEC (Forward Error Correction) layer, and a PCS (Physical Coding Sublayer) layer. The ONU 1 includes these functional units as common functional units.

  The MUX / DEMUX unit 12 transfers the Discovery Gate frame transmitted from the OLT 2 to the discovery process processing unit 11. The MUX / DEMUX unit 12 multiplexes the Register Request frame output from the discovery process processing unit 11 and transmits it to the OLT 2.

  The discovery process processing unit 11 includes a DiscoveryGate reception processing unit 111, a random delay & StartTime generation unit 112, and RegisterRequest transmission processing units 113-1 to 113-N (N is a natural number).

  The DiscoveryGate reception processing unit 111 receives the Discovery Gate frame transferred from the MUX / DEMUX unit 12, and notifies the random delay & starttime generation unit 112 of the StartTime information and the Length information in the Discovery Gate frame.

  The random delay & StartTime generation unit 112 describes the StartTime value (for example, StartTime [1], StartTime [2],..., StartTime [N]) of each LLID from the StartTime value and the Length value received from the DiscoveryGate reception processing unit 111. ) Is calculated and notified to the Register Request transmission processing units 113-1 to 113-N of each LLID.

  Each Register Request transmission processing unit 113-k (1 ≦ k ≦ N) transmits a Register Request frame when the transmission time reaches StartTime.

(A-2) Operation of Embodiment In order to establish a communication path between the OLT 2 and each ONU 1, a discovery process is performed.

  First, the OLT 2 transmits a Discovery Gate frame to each ONU 1 before starting communication.

  Each ONU 1 receives the Discovery Gate frame transmitted from the OLT 2 by the MUX / DEMUX unit 12. Then, the MUX / DEMUX unit 12 transfers the received Discovery Gate frame to the Discovery Gate reception processing unit 111.

  The DiscoveryGate reception processing unit 111 receives the Discovery Gate frame transferred from the MUX / DEMUX unit 12, and extracts StartTime information and Length information in the Discovery Gate frame. Then, the value of each extracted information (StartTime value and Length value) is notified to the random delay & StartTime generation unit 112.

  FIG. 2 is an explanatory diagram illustrating a process of generating a random delay by the random delay & StartTime generating unit 112.

  In FIG. 2, the random delay & StartTime generation unit 112 obtains a maxDelay value obtained by subtracting the time corresponding to the number of Register Request frames x LLIDs from the Length value. The reason for subtracting this value is to prevent the transmission time of a plurality of LLID Register Request frames combined with a random delay from exceeding the Length value.

  Next, the random delay & StartTime generating unit 112 randomly generates a value less than the maxDelay value, and sets the value as randomDelay. Here, the random delay & StartTime generation unit 112 generates one random Delay. The value of randomDelay can be obtained, for example, using a predetermined function formula that randomly obtains the value of randomDelay. For example, in the case of FIG. 2, a function formula that is randomly determined from a value of 0 or more and less than r (r is arbitrary) in the range of the value of maxDelay is used. Thereby, the value of randomDelay can be generated from the range of the value of maxDelay.

  Next, the random delay & StartTime generation unit 112 adds a randomDelay value to the StartTime value in the Discovery Gate frame, and further generates a StartTime value (StartTime [1]) of LLID # 1.

  Further, the random delay & StartTime generation unit 112 generates a value obtained by adding the time corresponding to one frame of Register Request to StartTime [1] as a StartTime value (StartTime [2]) of LLID # 2.

  Thereafter, the random delay & StartTime generation unit 112 generates StartTime values up to the maximum number of LLIDs (N) in the same manner as the StartTime [2] generation.

  Note that the random delay & StartTime generation unit 112 may generate a StartTime value after LLID # 2 and add a time corresponding to one or more Register Request frames.

  In this manner, by sequentially adding the transmission times of the Register Request frames of the LLIDs so as not to overlap, it is possible to prevent the collision of the Register Request frames. Further, only one random delay needs to be generated for one ONU 1. For this reason, there is no need to generate a random delay for all LLIDs as in the prior art, and therefore the time to establish a communication path can be shortened.

  When all the StartTime values are obtained, StartTime [1] is sent to the RegisterRequest transmission processing unit 113-1, StartTime [2] is sent to the RegisterRequest transmission processing unit 113-2,..., StartTime [N] is sent to the RegisterRequest transmission processing unit 113-. N is notified.

  Each Register Request transmission processing unit 113-1 to 113-N transmits a Register Request frame when the transmission time reaches StartTime.

  FIG. 3 is an explanatory diagram for explaining the time relationship of Register Request frame transmission of each LLID in the case of three LLIDs.

  As shown in FIG. 3, the Register Request frame of LLID # 1 is transmitted at the time StartTime [1], and the Register Request frame of LLID # 2 is transmitted at the time StartTime [2] at which the Register Request frame of LLID # 1 has been transmitted. Sent.

  In addition, the Register Request frame with LLID # 3 is transmitted at the time StartTime [3] when the Register Request frame with LLID # 2 has been transmitted. Therefore, it is possible to prevent a collision of Register Request frames among a plurality of LLIDs.

(A-3) Effect of Embodiment As described above, according to this embodiment, a random delay at the time of register request frame transmission in a plurality of LLID-compatible ONUs is generated per ONU instead of individually generating a plurality of LLIDs. One is generated, and the start time of each LLID is generated in order so that the Register Request frames do not overlap with each other based on the random delay value, so that collision of Register Request frames can be prevented. It is possible to shorten the time until the route is established.

(B) Other Embodiments (B-1) In the above-described embodiment, an embodiment applied to a GE-PON system using Gigabit Ethernet as a protocol of the PON system is shown. However, the embodiment is particularly limited to the GE-PON system. Even if the present invention is applied to another PON system that performs the same discovery process, the same effect can be obtained. In the above-described embodiment, the case of three LLIDs has been exemplified. However, the number of LLIDs is not particularly limited, and the same effect can be obtained even when the number of LLIDs is more than that.

(B-2) As a modified embodiment of the method for obtaining the transmission timing of the Register Request frame using each LLID, in the above-described embodiment, the RandomDelay value is added to the StartTime value so that the transmission times of the frames of each LLID do not overlap. However, a predetermined time may be inserted between the frame transmission time and the next frame transmission time to be added. For example, the insertion time value may be set in advance, or the insertion time may be determined according to the number of LLIDs from the time obtained by subtracting randomDelay from maxDelay.

(B-3) In the above-described embodiment, the processing in the ONU 1 can be realized by so-called software processing. In this case, for example, the ONU 1 has a CPU, ROM, RAM, EEROM or the like as a hardware configuration, and the CPU executes the processing program stored in the storage means such as the ROM using the data. .

DESCRIPTION OF SYMBOLS 1 ... ONU, 11 ... Discovery process processing part, 12 ... MUX / DEMUX part,
111 ... DiscoveryGate reception processing unit, 112 ... Random delay & StartTime generation unit, 113 ... ResisterRequest transmission processing unit,
2 ... OLT, 3 ... optical splitter, 4 ... optical cable.

Claims (3)

A user-side terminal device facing a station-side terminal device that constitutes an optical communication network is equipped with a plurality of pieces of identification information assigned to communication with the station-side terminal device, and relates to access control. In an access control device that transmits and receives a control frame to and from the station-side terminal device and performs synchronization with the station-side terminal device for each identification information,
Control frame receiving means for receiving a control frame for access control from the station-side terminal device;
When receiving the communication path search frame by the control frame receiving means, random delay generating means for generating one random delay value for the user side termination device;
The generated said random delay value, continue sequentially adding the frame transmission time required to transmit the communication path establishment request frame, the frame transmission timing generating means for determining a transmission timing of each communication path establishment request frame,
Based on the signal timing transmission each said determined for each of the identification information by the frame transmission timing generating means, characterized in that it comprises a control frame transmitting means for transmitting each communication channel establishment request frame to the station side terminating device Access control device.   The frame transmission timing generation means secures a maximum delay time that does not exceed the allowable time managed by the station-side terminal device, and the transmission time of all the communication path establishment request frames is determined from the start time of the maximum delay time. 2. The access control apparatus according to claim 1, wherein the frame transmission times of the communication path establishment request frames are sequentially added at the time when the random delay value is added. A user-side terminal device facing a station-side terminal device that constitutes an optical communication network is equipped with a plurality of pieces of identification information assigned to communication with the station-side terminal device, and relates to access control. In an access control program that transmits and receives a control frame to and from the station-side terminal device and performs synchronization with the station-side terminal device for each identification information,
Computer
Control frame receiving means for receiving a control frame related to access control from the station-side terminal device;
Random delay generating means for generating one random delay value for the user terminal device when receiving the communication path search frame by the control frame receiving means;
The generated said random delay value, continue sequentially adding the frame transmission time required to transmit the communication path establishment request frame, the frame transmission timing generating means for determining a transmission timing of each communication path establishment request frame,
Based on the signal timing transmission each said determined for each of the identification information by the frame transmission timing generating unit, a Rukoto the respective communication path establishment request frame to function as a control frame transmitting means for transmitting to said station side terminating device Feature access control program.

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