Communication Equipment

Abstract

To correct the situation where BER is high.SOLUTION: A communication device 100 establishes a link with a communication device 200 and is capable of communicating at a plurality of communication speeds. The communication device 100 includes a link control portion 150 and a measurement control unit 160 that measures BER on the basis of a data signal transmitted by the communication device 200, and transmits a link disconnection instruction to the link control portion 150 when the BER is greater than a preset threshold, and instructs the link control portion 150 to establish a link with the communication device 200 at a communication speed lower than the current communication speed. Upon receiving the link disconnection instruction, the link control portion 150 executes link disconnection processing, and executes processing for establishing a link with the communication device 200 at a communication speed lower than the current communication speed according to the instruction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] This disclosure relates to a communication device. Place Regarding. [Background technology]

[0002] It is known that a plurality of communication devices communicate via a wired network. Among the communication devices, there are communication devices whose Ethernet (registered trademark) interface supports a plurality of communication speeds. When linking up, the communication device performs AutoNegotiation because it is unclear whether the connected communication device supports all communication speeds. This determines the communication mode, communication speed, and the like (see Non-Patent Document 1 and Non-Patent Document 2). In addition, a communication device having a Downshift function is known. In the communication device, training is performed by PBO (Power Back Off). If the training result is NG, the communication device can optimize the communication speed by lowering the communication speed of the communication standard to 10GBASE-T, 5GBASE-T, 1000BASE-T, and 100BASE-TX (see Non-Patent Document 2). Moreover, Patent Document 1 proposes a link-up method. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] IEEE802.3-2018 [Non-Patent Document 2] NBASE-T Physical Layer Specification version2.3 [Patent documents]

[0004] [Patent Document 1] JP 2004-304470 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the Downshift described above, only training by PBO is performed. Therefore, when using Cat.5e cable, which is widely used for 1000BASE-T, or when a Cat.6a or higher cable has deteriorated over time, the training result may coincidentally be OK. If the training result coincidentally turns out to be OK, a link based on a communication speed higher than the capability will be established. If this link is established, there is a problem that communication will take place in a situation where the BER (Bit Error Rate) is high.

[0006] The objective of this disclosure is to remedy high BER situations. [Means for solving the problem]

[0007] According to an embodiment of the present disclosure, there is provided a communication device capable of communicating at a plurality of communication speeds. The communication device includes a link control unit that establishes a link with a first communication device by performing AutoNegotiation and training with Power Back Off, and measures a bit error rate based on a data signal transmitted by the first communication device. The bit error rate is compared with a preset threshold value. A measurement control unit; a data generating unit that generates a link disconnection declaration frame indicating a link disconnection notice when data communication is not being performed between the communication device and the first communication device after it is determined that the bit error rate is greater than the threshold value, a data transmitting unit that transmits the link disconnection declaration frame to the first communication device, and an instruction control unit that transmits a link disconnection instruction to the link control unit when a link disconnection permission frame that is a response frame to the link disconnection declaration frame is received, and instructs the link control unit to establish a link with the first communication device at a communication speed slower than a current communication speed. When the link disconnection instruction is received, the link control unit executes a link disconnection process, and performs a process for establishing a link with the first communication device at a communication speed slower than a current communication speed in accordance with the instruction. Effect of the Invention

[0008] According to the present disclosure, high BER situations can be remedied. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 illustrates a communication system according to a first embodiment. [Diagram 2]FIG. 2 is a diagram illustrating hardware included in a communication device according to a first embodiment. [Diagram 3] 4 is a flowchart illustrating an example of processing executed by the communication device according to the first embodiment. [Figure 4] 11 is a flowchart illustrating an example of processing executed by a communication device according to a second embodiment. [Diagram 5] FIG. 11 is a block diagram showing the functions of a communication device serving as a connection source according to the third embodiment. [Figure 6] FIG. 11 is a block diagram showing the functions of a connection destination communication device according to the third embodiment. [Figure 7] 13 is a flowchart (part 1) illustrating an example of processing executed by a source communication device according to the third embodiment. [Figure 8] 13 is a flowchart (part 2) illustrating an example of the process executed by a connection source communication device according to the third embodiment. [Figure 9] 13 is a flowchart (part 3) illustrating an example of processing executed by a source communication device of the third embodiment. [Figure 10] 13 is a flowchart illustrating an example of a process executed by a destination communication device according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment will be described with reference to the drawings. The following embodiment is merely an example, and various modifications are possible within the scope of the present disclosure.

[0011] Embodiment 1 1 is a diagram showing a communication system according to the first embodiment. The communication system includes a communication device 100 and a communication device 200. The communication device 100 and the communication device 200 are connected via a wired cable. The communication device 100 is a device that executes the control method. The communication device 100 is a communication device that is capable of communicating at a plurality of communication speeds. The communication device 200 is also called a first communication device.

[0012] Here, the hardware of the communication device 100 will be described. 2 is a diagram showing hardware included in the communication device of embodiment 1. The communication device 100 includes a processor 101, a volatile storage device 102, and a non-volatile storage device 103.

[0013] The processor 101 controls the entire communication device 100. For example, the processor 101 is a central processing unit (CPU) or a field programmable gate array (FPGA). The processor 101 may be a multiprocessor. The communication device 100 may also have a processing circuit. The processing circuit may be a single circuit or a composite circuit.

[0014] The volatile storage device 102 is a main storage device of the communication device 100. For example, the volatile storage device 102 is a random access memory (RAM). The non-volatile storage device 103 is an auxiliary storage device of the communication device 100. For example, the non-volatile storage device 103 is a hard disk drive (HDD), a solid state drive (SSD), or a flash memory.

[0015] 1, a description will be given of functions of the communication device 100. The communication device 100 has a data generating unit 110, a data transmitting unit 120, a data receiving unit 130, a data processing unit 140, a link control unit 150, and a measurement control unit 160.

[0016] A part or all of the data generating unit 110, the data transmitting unit 120, the data receiving unit 130, the data processing unit 140, the link control unit 150, and the measurement control unit 160 may be realized by a processing circuit. Also, a part or all of the data generating unit 110, the data transmitting unit 120, the data receiving unit 130, the data processing unit 140, the link control unit 150, and the measurement control unit 160 may be realized as a module of a program executed by the processor 101. For example, the program executed by the processor 101 is also called a control program. For example, the control program is recorded on a recording medium.

[0017] The data generating unit 110 generates a data signal. The data generating unit 110 is also called a MAC (Media Access Controller). The data transmitting unit 120 converts the data signal into a signal suited to the communication device 200, and transmits the converted signal to the communication device 200. The data transmitting unit 120 is also called a physical layer device. The data receiving unit receives a data signal from the communication device 200. The data processing unit 140 processes the data signal received by the data receiving unit .

[0018] Link control unit 150 has an AutoNegotiation function and a Downshift function. Link control unit 150 performs a process for establishing a link. Link control unit 150 may also perform a process for disconnecting a link.

[0019] The measurement control section 160 measures the BER (i.e., bit error rate). For example, the measurement control section 160 calculates the BER based on errors in a frame check sequence included in a data signal (i.e., a frame). The measurement control section 160 may also calculate the BER using the following formula (1). α is a numerical value. α is determined depending on how many bit errors there are in one block before correction is possible.

[0020]

number

[0021] Furthermore, the measurement control section 160 may calculate the BER from the number of blocks that could not be restored to 64B based on an error in the 64B / 65B code. Furthermore, the measurement control section 160 may calculate the BER using the following formula (2).

[0022]

number

[0023] Next, the process executed by the communication device 100 will be described with reference to a flowchart. FIG. 3 is a flowchart illustrating an example of a process executed by the communication device according to the first embodiment. (Step S11) The link control unit 150 executes AutoNegotiation and performs training by PBO between the communication device 100 and the communication device 200. If the training result is NG, the link control unit 150 performs Downshift. The link is established by the processing of the link control unit 150.

[0024] (Step S12) The measurement control unit 160 measures the BER based on the data signal transmitted by the communication device 200. (Step S13) The measurement control unit 160 determines whether the BER is equal to or less than a preset threshold. If the BER is equal to or less than the threshold, the process proceeds to step S16. If the BER is greater than the threshold, the process proceeds to step S14.

[0025] (Step S14) The measurement control unit 160 transmits a link disconnection instruction to the link control unit 150. Furthermore, the measurement control unit 160 instructs the link control unit 150 to establish a link with the communication device 200 at a communication speed slower than the current communication speed.

[0026] (Step S15) The link control unit 150 executes a link disconnection process. As a result, the link between the communication device 100 and the communication device 200 is disconnected. Then, the process proceeds to step S11. In step S11, the link control unit 150 performs a process for establishing a link with the communication device 200 at a communication speed slower than the current communication speed in accordance with the instruction. As a result, communication is performed at a slow communication speed in the next established link. Therefore, the high BER situation is corrected. (Step S16) The connection state between communication device 100 and communication device 200 is maintained.

[0027] According to the first embodiment, when the BER is greater than the threshold, the communication device 100 executes a link disconnection process. Then, the communication device 100 re-establishes the link. The link is established at a communication speed slower than the current communication speed. Therefore, the high BER situation is corrected. Therefore, the communication device 100 can correct the high BER situation.

[0028] Embodiment 2 Next, a description will be given of embodiment 2. In embodiment 2, differences from embodiment 1 will be mainly described. In embodiment 2, descriptions of matters common to embodiment 1 will be omitted. In the first embodiment, a case where a high BER is corrected immediately after a link is established is described. There is a high possibility that the wired cable between the communication device 100 and the communication device 200 will deteriorate over time. In the second embodiment, a method for dealing with such a case is described.

[0029] Next, the process executed by the communication device 100 will be described with reference to a flowchart. Fig. 4 is a flowchart showing an example of a process executed by the communication device of the second embodiment. The process in Fig. 4 differs from the process in Fig. 3 in that step S17 is executed. Therefore, step S17 will be described in Fig. 4. Descriptions of the processes other than step S17 will be omitted. (Step S17) The measurement control unit 160 waits for a preset time. Then, the process proceeds to step S12. In this way, the communication device 100 periodically monitors the BER.

[0030] As described above, when the BER is equal to or less than the threshold, the measurement control section 160 measures the BER again based on the data signal transmitted by the communication device 200 after a preset time has elapsed.

[0031] According to the second embodiment, the communication device 100 can correct a high BER situation caused by deterioration of the wired cable by repeating the measurement of the BER.

[0032] Furthermore, the measurement control unit 160 may transmit a link disconnection instruction to the link control unit 150 when the number of times the BER is equal to or less than the threshold is equal to or greater than a preset numerical value. Furthermore, the measurement control unit 160 instructs the link control unit 150 to establish a link with the communication device 200 at a communication speed higher than the current communication speed. The link control unit 150 executes a link disconnection process. Then, the link control unit 150 performs a process for establishing a link with the communication device 200 at a communication speed (e.g., a communication speed of 10GBASE-T) higher than the current communication speed (e.g., a communication speed of 5GBASE-T) according to the instruction. As a result, communication is performed at the higher communication speed in the next established link. Thus, the communication device 100 can communicate with the communication device 200 at an optimal communication speed.

[0033] Embodiment 3 Next, a description will be given of embodiment 3. In embodiment 3, differences from embodiment 2 will be mainly described. Furthermore, in embodiment 3, descriptions of matters common to embodiment 2 will be omitted. In the second embodiment, a method for correcting a situation in which the BER is high after a certain amount of time has passed is described. In the third embodiment, a method for correcting a situation in which the BER is high and no data communication is being performed is described.

[0034] Fig. 5 is a block diagram showing the functions of a connection source communication device of embodiment 3. The components in Fig. 5 that are the same as those in Fig. 1 are assigned the same reference numerals as those in Fig. 1. The communication device 100a has a transmission counter unit 170, a reception counter unit 180, and an instruction control unit 190.

[0035] The transmission counter unit 170, the reception counter unit 180, and the instruction control unit 190 may be partly or entirely realized by a processing circuit. Also, the transmission counter unit 170, the reception counter unit 180, and the instruction control unit 190 may be partly or entirely realized as a program module executed by the processor 101.

[0036] The transmission counter unit 170 counts the number of transmission frames that are transmitted to the communication device 200a. The reception counter unit 180 counts the number of reception frames, which is the number of reception frames received from the communication device 200a. The function of the instruction control unit 190 will be explained later.

[0037] 6 is a block diagram showing functions of a communication device to which a connection is made in the third embodiment. The communication device 200a includes a data receiving unit 210, a data processing unit 220, an instruction control unit 230, a data generating unit 240, and a data transmitting unit 250. The communication device 200a is also referred to as a first communication device.

[0038] A part or all of the data receiving unit 210, the data processing unit 220, the instruction control unit 230, the data generating unit 240, and the data transmitting unit 250 may be realized by a processing circuit included in the communication device 200a. Also, a part or all of the data receiving unit 210, the data processing unit 220, the instruction control unit 230, the data generating unit 240, and the data transmitting unit 250 may be realized as a program module executed by a processor included in the communication device 200a.

[0039] The functions of the data receiving unit 210, the data processing unit 220, the instruction control unit 230, the data generating unit 240, and the data transmitting unit 250 will be described later.

[0040] Next, the process executed by the communication device 100a will be described with reference to a flowchart. FIG. 7 is a flowchart (part 1) illustrating an example of processing executed by a source communication device according to the third embodiment. (Step S21) The link control unit 150 executes AutoNegotiation between the communication device 100a and the communication device 200a, and also executes training by PBO. If the training result is NG, the link control unit 150 executes Downshift. The link is established by the processing of the link control unit 150.

[0041] (Step S22) The instruction control unit 190 determines whether or not data transmission to the communication device 200a has been stopped. There is a possibility that data transmission to the communication device 200a has been stopped by step S41, which will be described later. Therefore, step S22 is performed. If the data transmission has been stopped, the process proceeds to step S23. If the data transmission has not been stopped, the process proceeds to step S24.

[0042] (Step S23) The instruction control unit 190 instructs the data transmission unit 120 to start data transmission. This starts data transmission. (Step S24) The measurement control unit 160 measures the BER based on the data signal transmitted by the communication device 200a.

[0043] (Step S25) The measurement control unit 160 determines whether or not the BER is equal to or less than a preset threshold. If the BER is equal to or less than the threshold, the process proceeds to step S26. If the BER is greater than the threshold, the process proceeds to step S31. (Step S26) The measurement control unit 160 waits for a preset time. Then, the process proceeds to step S24. In this manner, the communication device 100a periodically monitors the BER.

[0044] FIG. 8 is a flowchart (part 2) illustrating an example of the process executed by the source communication device according to the third embodiment. (Step S31) The transmission counter unit 170 counts the number of transmission frames at n1 second intervals. Here, "n1", "n2" and "n3" described later are arbitrary numerical values ​​and are preset numerical values. (Step S32) The instruction control unit 190 determines whether or not the transmission count number of the transmission counter unit 170 has been zero n2 consecutive times. If the transmission count number has been zero n2 consecutive times, the process proceeds to step S34. If the transmission count number has not been zero n2 consecutive times, the process proceeds to step S33.

[0045] (Step S33) The transmission counter unit 170 waits for n3 seconds. Then, the process proceeds to step S31. (Step S34) The reception counter unit 180 counts the number of received frames at intervals of n1 seconds.

[0046] (Step S35) The instruction control unit 190 determines whether the reception count number of the reception counter unit 180 has been zero n2 consecutive times. If the reception count number is not zero n2 consecutive times, the process proceeds to step S33. If the reception count number is zero n2 consecutive times, the instruction control unit 190 determines that data communication is not taking place between the communication device 100a and the communication device 200a. The instruction control unit 190 instructs the data generation unit 110 to generate a link disconnection declaration frame that indicates a notice of link disconnection. Then, the process proceeds to step S36.

[0047] (Step S36) The data generator 110 generates a link disconnection declaration frame. (Step S37) The data transmitting unit 120 transmits a link disconnection declaration frame to the communication device 200a. (Step S38) The instruction control unit 190 determines whether the data receiving unit 130 has received a link disconnection permission frame from the communication device 200a. The link disconnection permission frame is a response frame to the link disconnection declaration frame. If the link disconnection permission frame has been received, the process proceeds to step S41. If the link disconnection permission frame has not been received, the process ends.

[0048] FIG. 9 is a flowchart (part 3) illustrating an example of the process executed by the source communication device according to the third embodiment. (Step S41) The instruction control unit 190 instructs the data transmission unit 120 to stop data transmission. (Step S42) The instruction control unit 190 transmits a link disconnection instruction to the link control unit 150. Furthermore, the instruction control unit 190 instructs the link control unit 150 to establish a link with the communication device 200a at a communication speed slower than the current communication speed.

[0049] (Step S43) The link control unit 150 executes a link disconnection process. As a result, the link between the communication device 100a and the communication device 200a is disconnected. Then, the process proceeds to step S21. In step S21, the link control unit 150 performs a process for establishing a link with the communication device 200a at a communication speed slower than the current communication speed in accordance with the instruction. As a result, communication is performed at a slow communication speed in the next established link. Therefore, the high BER situation is corrected.

[0050] Next, the process executed by the communication device 200a will be described with reference to a flowchart. FIG. 10 is a flowchart illustrating an example of a process executed by a destination communication device according to the third embodiment. (Step S51) The data receiving unit 210 receives a link disconnection declaration frame from the communication device 100a. The instruction control unit 230 detects that the link disconnection declaration frame has been received via the data processing unit 220. The instruction control unit 230 instructs the data generating unit 240 to generate a link disconnection permission frame.

[0051] (Step S52) The data generator 240 generates a link disconnection permission frame. (Step S53) The data transmitting unit 250 transmits a link disconnection permission frame to the communication device 100a. (Step S54) The instruction control unit 230 instructs the data transmission unit 250 to stop data transmission. If a link is established again after step S54, the communication device 200a starts communication with the communication device 100a.

[0052] According to the third embodiment, the communication device 100a confirms that data communication is not being performed between the communication device 100a and the communication device 200a, and when the communication device 100a receives a link disconnection permission frame, the communication device 100a disconnects the link. Therefore, the communication device 100a can prevent the communication device 100a from unilaterally disconnecting the link while data communication is being performed.

[0053] The features of each of the embodiments described above can be combined with each other as appropriate. [Explanation of symbols]

[0054] 100 communication device, 100a communication device, 101 processor, 102 volatile memory device, 103 non-volatile memory device, 110 data generation unit, 120 data transmission unit, 130 data reception unit, 140 data processing unit, 150 link control unit, 160 measurement control unit, 170 transmission counter unit, 180 reception counter unit, 190 instruction control unit, 200 communication device, 200a communication device, 210 data reception unit, 220 data processing unit, 230 instruction control unit, 240 data generation unit, 250 data transmission unit.

Claims

1. A communication device capable of communicating at a plurality of communication speeds, a link control unit that establishes a link with the first communication device by executing AutoNegotiation and performing training with Power Back Off; a measurement control unit that measures a bit error rate based on a data signal transmitted by the first communication device and compares the bit error rate with a preset threshold value; a data generating unit that generates a link disconnection declaration frame indicating a link disconnection notice when data communication is not being performed between the communication device and the first communication device after it is determined that the bit error rate is greater than the threshold value; a data transmission unit that transmits the link disconnection declaration frame to the first communication device; an instruction control unit that, when receiving a link disconnection permission frame that is a response frame to the link disconnection declaration frame, transmits a link disconnection instruction to the link control unit and instructs the link control unit to establish a link with the first communication device at a communication speed slower than a current communication speed; having the link control unit, when receiving the link disconnection instruction, executes a link disconnection process, and performs a process for establishing a link with the first communication device at a communication speed slower than a current communication speed in accordance with the instruction. Communications equipment.

2. When the bit error rate is equal to or less than the threshold value, the measurement control unit measures the bit error rate again after a preset time has elapsed based on the data signal transmitted by the first communication device. The communication device according to claim 1 .

3. When the number of times that the bit error rate is equal to or less than the threshold is equal to or greater than a preset value, the measurement control unit transmits the link disconnection instruction to the link control unit and instructs the link control unit to establish a link with the first communication device at a communication speed faster than a current communication speed; the link control unit, when receiving the link disconnection instruction, executes a link disconnection process, and performs a process for establishing a link with the first communication device at a communication speed higher than a current communication speed in accordance with the instruction. The communication device according to claim 2 .

Images