A method and system for allocating time slots for downlink transmission in an optical and wireless converged network

Abstract

The present invention relates to a method and system for allocating time slots for downlink transmission in an optical and wireless converged network, wherein the method comprises: in the optical and wireless converged network, obtaining a predicted throughput C sent by a wireless access point AP to a mobile station STA and a remaining amount B in a downlink data buffer area of ​​the wireless access point AP; constructing a downlink transmission time slot of an optical network unit ONU according to the predicted throughput C and the remaining amount B in a downlink data buffer area of ​​the wireless access point AP, wherein each of the optical network units ONU is connected to a wireless access point AP; comparing the constructed downlink transmission time slot of the optical network unit ONU with the downlink transmission time slot of the original optical network unit ONU in the optical and wireless converged network, and taking the smaller value as the final downlink transmission time slot of the optical network unit ONU. The present invention can dynamically allocate the size of the downlink time slot sent to each ONU, and can prevent downlink data from being lost in the buffer area of ​​the wireless access point AP.

Description

Technical Field

[0001] The invention relates to the technical field of wireless optical network time slot allocation, and in particular to a method and system for allocating time slots for downlink transmission in an optical and wireless fusion network. Background Art

[0002] In recent years, with the development of fiber-to-the-home (FTTR) technology, the use of Wi-Fi to access passive optical networks (PON) has been widely used. In order to meet the main features of the fifth-generation fixed network (F5G), all-optical connection, enhanced fixed broadband, and guaranteed ultimate experience (i.e., zero packet loss and microsecond latency), the Wi-Fi protocol IEEE802.11be (Wi-Fi7) is being revised, mainly introducing multi-link operation, multi-RU (Resource Unit) and other functions, aiming to provide more flexible links and bandwidth sizes than Wi-Fi6, thereby ensuring higher speed and more stable data transmission. On the other hand, the ITU-T's 50G-PON project supports a rate of up to 50Gbps per channel wavelength, which will be able to meet the large bandwidth requirements of Wi-Fi backhaul networks.

[0003] As an important technology in PON, the Time Division Multiplexing-Passive Optical Network (TDM-PON) based on time division multiplexing technology has the advantages of high bandwidth and low cost and is widely deployed. TDM-PON uses time division multiple access (TDMA) technology for uplink transmission, and can use dynamic bandwidth allocation (DBA) technology to reduce latency and improve bandwidth utilization. In downlink transmission, TDM-PON uses broadcast mode, that is, the optical line terminal (OLT) sends data frames to all optical network units (ONUs). The ONU determines whether the XGEM frame belongs to itself based on the XGEM Port-ID field in the XGEM (10-Gigabit-capable PONEncapsulation Method) header, and then decides to receive or discard it.

[0004] The highest-order modulation scheme available for IEEE 802.11ax is 1024-QAM, in which the modulation symbol carries 10 bits. In order to further increase the peak rate, IEEE 802.11be can use up to 4096-QAM, so that the modulation symbol can carry 12 bits. Therefore, at the same coding rate, its data rate can be increased by 20% compared with 1024-QAM. Multi-RU (Resource Unit) uses preamble puncturing technology to increase the transmission bandwidth and thus the transmission rate through channel bonding. Multi-link operation uses multiple access channels to coordinate switching to complete the transmission. Due to the limitation of the 6GHz frequency band, the promotion and application of Wi-Fi7 will be partially restricted. Multi-AP collaboration (MAPC) includes collaborative spatial reuse (CSR), collaborative beamforming (CBF), collaborative OFDMA (C-OFDMA), etc. Although MAPC was not ultimately included in the scope of Wi-Fi7, relevant standards will be further formulated in Wi-Fi8.

[0005] With the development of wireless communication technology, spectrum resources below 6GHz are seriously occupied. The main transmission frequency bands are 2.4GHz and 5GHz Wi-Fi, and its transmission is easily affected by channel quality. Since the media access control layer (MAC) of Wi-Fi uses the carrier sense multiple access / collision avoidance (CSMA / CA) mechanism, under this mechanism, when there is channel interference or other devices occupying the channel, its access rate will be greatly reduced, and the throughput will also decrease.

[0006] In terms of PON, downstream transmission is different from upstream transmission. Upstream transmission has dynamic bandwidth allocation to improve bandwidth utilization and reduce latency. Downstream transmission uses the idea of ​​full-frame transmission, that is, when the amount of data reaching the OLT can form a 125-microsecond GTC frame, the GTC frame will be sent. Although this can ensure low-latency transmission in the downstream, it ignores whether the AP mounted after the ONU can send the data in its data cache to the corresponding mobile station (STA) through the Wi-Fi channel in time.

[0007] With the gradual commissioning of 50G-PON, the transmission resources in the optical network still have redundant bandwidth resources while ensuring high-speed data transmission. This causes a mismatch between optical transmission resources and wireless transmission resources, resulting in overflow of the data buffer of the AP mounted behind the ONU (that is, the AP has not yet sent the data in the buffer through the air interface, and the new packet has to be discarded because the data buffer is full), causing data packet loss. Since PON has no retransmission mechanism, the lost data will not be resent, and by the time the user requests data again from the upper layer of the STA, it has caused an unbearable delay. Therefore, a method that can dynamically adjust the time slot allocation based on the AP buffer status and throughput prediction is needed in the passive optical network accessed by Wi-Fi. Summary of the invention

[0008] To this end, the technical problem to be solved by the present invention is to overcome the mismatch between optical transmission resources and wireless transmission resources in the prior art, which causes the data buffer area of ​​the AP (i.e., wireless access point) mounted behind the ONU to overflow, resulting in packet loss.

[0009] In order to solve the above technical problems, the present invention provides a time slot allocation method for downlink transmission in an optical and wireless converged network, comprising:

[0010] Step S1: in the optical and wireless converged network, obtaining the predicted throughput C sent by the wireless access point AP to the mobile station STA and the remaining amount B in the downlink data buffer area of ​​the wireless access point AP;

[0011] Step S2: constructing a downlink transmission time slot of an optical network unit ONU according to the predicted throughput C and the remaining amount B of the downlink data buffer area of ​​the wireless access point AP, wherein each of the optical network units ONU is connected to a wireless access point AP;

[0012] Step S3: compare the constructed downlink transmission time slot of the optical network unit ONU with the downlink transmission time slot of the original optical network unit ONU in the optical and wireless converged network, and take the smaller value as the final downlink transmission time slot of the optical network unit ONU.

[0013] In one embodiment of the present invention, the expression of the predicted throughput C in step S1 is:

[0014]

[0015] in, The predicted throughput of voice calls in the wireless access control server AC is the predicted throughput of voice services in the wireless access controller. represents the predicted throughput of the wireless access controller for the video service access category, It indicates the predicted throughput of the wireless access controller with the access category of best effort transmission. Indicates the predicted throughput of background traffic in the wireless access controller.

[0016] In one embodiment of the present invention, the expression of the remaining amount B of the downlink data buffer area of ​​the wireless access point AP in step S1 is:

[0017] B=[B AC_VO B AC_VI B AC_BE B AC_BK ]

[0018] Among them, B AC_VO Indicates the remaining amount of downlink data buffer in the wireless access controller with access category of voice service, B AC_VI Indicates the remaining amount of downlink data buffer in the wireless access controller with access category of video service, B AC_BE Indicates the remaining amount of downlink data buffer in the wireless access controller with the access category of best effort transmission, B AC_BK Indicates the remaining amount of downlink data buffer in the wireless access controller with access category of background traffic.

[0019] In one embodiment of the present invention, in step S2, the downlink transmission time slot of the optical network unit ONU is constructed according to the predicted throughput C and the remaining amount B of the downlink data buffer area of ​​the wireless access point AP, and the method includes:

[0020] The downlink data volume D of the ac-th AP access category of the i-th optical network unit ONU is constructed according to the predicted throughput C and the remaining amount B of the downlink data buffer area of ​​the wireless access point AP i,ac The conditional formula is optimized to obtain the downstream data volume D of the ac-th AP access category of the i-th optical network unit ONU i,ac The optimization formula of

[0021] According to the downlink data volume D of the ac-th AP access category of the i-th optical network unit ONU i,ac The optimization formula is used to construct the downlink transmission time slot of the optical network unit ONU.

[0022] In one embodiment of the present invention, the amount of downlink data D of the ac-th AP access category of the i-th optical network unit ONU is i,ac The conditional formula is expressed as:

[0023]

[0024] Where, τ is the MAC layer interaction delay between AP and OLT, C i,acis the throughput of the ac-th AP access category of the i-th ONU, B i,ac is the remaining size of the buffer area of ​​the ac-th AP access category of the i-th ONU, and T is the period of the MAC layer interaction delay arrival.

[0025] In one embodiment of the present invention, the conditional formula is optimized to obtain the downlink data volume D of the ac-th AP access category of the i-th optical network unit ONU: i,ac The optimization formula is expressed as:

[0026]

[0027] In one embodiment of the present invention, according to the ac-th AP access category downlink data volume D of the i-th optical network unit ONU, i,ac The optimization formula of constructing the downlink transmission time slot of the optical network unit ONU includes:

[0028] Set up a matrix A with N*AC elements all set to 1 N×AC , the wireless access control server AC classifies the access in each wireless access point AP, including four ac classes: AC_VO, AC_VI, AC_BE, and AC_BK;

[0029] In the period T, at the current time step, if the amount of data of ac classes sent to the i-th wireless access point AP satisfies the optimization formula, let the matrix A N×AC The corresponding element A in i,ac It still remains at 1, indicating that the buffer area in the corresponding wireless access point AP is not full, and the optical line terminal OLT is based on the corresponding element A i,ac If it still remains at 1, the optical line terminal OLT continues to send the data of the access category of the ac-th wireless access point AP to the i-th optical network unit ONU;

[0030] In the period T, at the next time step, continue to determine whether the amount of data of the ac classes sent to the i-th wireless access point AP satisfies the optimization formula. If it does not satisfy the optimization formula, let the matrix A N×AC The corresponding element A in i,ac = 0, indicating that the cache area of ​​the ac class in the wireless access point AP is full, and the optical line terminal OLT is based on the corresponding element A i,ac If it is 0, the optical line terminal OLT is stopped from sending the data of the access category of the ac-th wireless access point AP to the i-th optical network unit ONU; when the accumulated time step reaches the period T, the loop is exited;

[0031] The downlink transmission time slot sent by OLT to the i-th optical network unit ONU in period T is expressed as:

[0032]

[0033] Here, Rate represents the rate of downlink transmission in the passive optical network.

[0034] In order to solve the above technical problems, the present invention provides a time slot allocation system for downlink transmission in an optical and wireless converged network, comprising:

[0035] Acquisition module: used to obtain the predicted throughput C sent by the wireless access point AP to the mobile station STA and the remaining amount B of the downlink data buffer area of ​​the wireless access point AP in the optical and wireless converged network;

[0036] A construction module: used to construct a downlink transmission time slot of an optical network unit ONU according to the predicted throughput C and the remaining amount B of the downlink data buffer area of ​​the wireless access point AP, wherein each of the optical network units ONU is connected to a wireless access point AP;

[0037] Time slot allocation module: used to compare the constructed optical network unit ONU's downlink transmission time slot with the original optical network unit ONU's downlink transmission time slot in the optical and wireless converged network, and take the smaller value as the final optical network unit ONU's downlink transmission time slot.

[0038] To solve the above technical problems, the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the time slot allocation method for downlink transmission in the above optical and wireless converged network are implemented.

[0039] To solve the above technical problems, the present invention provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the time slot allocation method for downlink transmission in the above optical and wireless converged network are implemented.

[0040] The above technical solution of the present invention has the following advantages compared with the prior art:

[0041] The present invention matches optical transmission resources with wireless transmission resources without affecting the original downlink mechanism and efficiency, thereby reducing the overflow of the downlink data buffer area of ​​the wireless access point AP as much as possible;

[0042] The OLT of the present invention can dynamically allocate the size of the downlink time slot sent to each ONU according to the throughput prediction information and the buffer status report transmitted by the AP, and can prevent the downlink data from being lost in the buffer area of ​​the wireless access point AP and reduce the delay as much as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0044] Figure 1 is a flow chart of the method of the present invention;

[0045] Figure 2 is a schematic diagram of an optical and wireless fusion network in an embodiment of the present invention;

[0046] Figure 3 is a flow chart of a time slot allocation algorithm for downlink transmission in an embodiment of the present invention;

[0047] Figure 4 It is a schematic diagram of packet loss reduction brought about by the time slot allocation algorithm in an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0049] Embodiment 1

[0050] Reference Figure 1 The present invention relates to a time slot allocation method for downlink transmission in an optical and wireless converged network, comprising:

[0051] Step S1: in the optical and wireless converged network, obtaining the predicted throughput C sent by the wireless access point AP to the mobile station STA and the remaining amount B in the downlink data buffer area of ​​the wireless access point AP;

[0052] Step S2: constructing a downlink transmission time slot of an optical network unit ONU according to the predicted throughput C and the remaining amount B of the downlink data buffer area of ​​the wireless access point AP, wherein each of the optical network units ONU is connected to a wireless access point AP;

[0053] Step S3: Compare the constructed downlink transmission time slot of the optical network unit ONU with the downlink transmission time slot of the original optical network unit ONU in the optical and wireless converged network, and take the smaller value as the final downlink transmission time slot of the optical network unit ONU

[0054] The optical line terminal OLT is connected to a number of optical network units ONU, each of the optical network units ONU is connected to a wireless access point AP, and the wireless access point AP is connected to a mobile station STA.

[0055] The following is a detailed introduction to this embodiment:

[0056] The present invention designs a time slot allocation algorithm for downlink transmission executed by a downlink traffic scheduler in an OLT, which aims to reduce the overflow of the downlink data buffer area of ​​some APs of Wi-Fi as much as possible without affecting the original downlink mechanism and efficiency.

[0057] The predicted throughput matrix (i.e., the throughput between the wireless access point AP and the mobile station STA) to be reported to the OLT can be written as:

[0058]

[0059] in, The predicted throughput of voice calls in the wireless access control server (AC) is the predicted throughput of voice services in the wireless access controller. represents the predicted throughput of the wireless access controller for the video service access category, It indicates the predicted throughput of the wireless access controller with the access category of best effort transmission. Indicates the predicted throughput of background traffic in the wireless access controller.

[0060] The remaining amount of the AP downlink data buffer reported to the OLT is recorded as:

[0061] B=[B AC_VO B AC_VI B AC_BE B AC_BK ]

[0062] Among them, B AC_VO Indicates the remaining amount of downlink data buffer in the wireless access controller with access category of voice service, B AC_VI Indicates the remaining amount of downlink data buffer in the wireless access controller with access category of video service, B AC_BE Indicates the remaining amount of downlink data buffer in the wireless access controller with the access category of best effort transmission, B AC_BK Indicates the remaining amount of the downlink data buffer in the wireless access controller with access category as background traffic. Through information exchange, the information including the remaining capacity of the AP buffer and the downlink throughput is sent to the downlink traffic scheduler of the OLT, and the MAC layer (corresponding to AP) and OLT are recorded. Figure 2 The interaction delay between the service adaptation sublayer and the GTC framing sublayer is τ, which is related to the actual uplink scheduling mode of the PON and is in the order of microseconds. Let the number of ONUs be N, then the throughput of the ac-th AP access category of the i-th ONU can be expressed as C i,ac , the remaining size of the buffer area of ​​the ac-th AP access category of the i-th ONU is B i,ac , let the period of MAC layer interaction delay arrival be T, then the amount of downlink data of the ac-th AP access category of the i-th ONU is D i,ac (i.e. the amount of data sent by the AP to the STA) needs to meet the following requirements:

[0063]

[0064] Since the reported throughput is a real number and can be considered a constant in one cycle, the above formula can be rewritten as an optimization formula:

[0065]

[0066] Specifically, in this embodiment, a matrix A is set with all N*AC elements (i.e., the buffer overflow flag) set to 1. N×AC (AC is the access classification in each AP, including four AC classes: AC_VO, AC_VI, AC_BE, and AC_BK). Figure 3 As shown, within the period T, at the current time step (a time step is t1), if the amount of data of ac classes sent to the i-th wireless access point AP satisfies the optimization formula (*), let the matrix A N×AC The corresponding element A in i,ac It still remains at 1, which means that the buffer area in the corresponding wireless access point AP is not full, and the optical line terminal OLT is based on the corresponding element A i,ac If it remains at 1, the OLT continues to send the access category data of the corresponding AP to the ONU. In the period T, at the next time step, continue to determine whether the optimization formula (*) is satisfied. Each time, only Figure 3 Is the cache full at time t1? If not, let matrix A N×AC Element A in i,ac = 0, indicating that the cache area of ​​the ac class in the AP is full, and the optical line terminal OLT is based on the corresponding element A i,ac If it is 0, the optical line terminal OLT is stopped from sending data of the ac-th AP access category to the i-th ONU.

[0067] The downlink transmission time slot sent by OLT to the i-th optical network unit ONU in period T is expressed as:

[0068]

[0069] Here, Rate represents the rate of downlink transmission in the passive optical network.

[0070] In this embodiment, the optical line terminal OLT encapsulates the received data into an XGEM frame, and further encapsulates it into a physical layer (PHY) frame with a length of 125 microseconds and sends it to the ONU frame. The ONU receives its own frame according to the information in the XGEM frame header, and then sends the received data to the wireless access point AP. The wireless access point AP stores the received data in the cache area of ​​the ac class.

[0071] Then, together with the originally allocated time slot g i,ac Compare and take the smaller value as the final time slot allocation, that is:

[0072]

[0073] In a 50G-PON, 25 ONUs are mounted, and their downstream rates are all 50Gbps. Each ONU is connected to a Wi-Fi access point used in the FTTR scenario. Under normal conditions, the modulation code scheme (MCS) of each Wi-Fi access point selects 11, corresponding to 802.11ax (Wi-Fi6) OFDM downstream transmission, with 2 spatial streams, 1024-QAM modulation, and 5 / 6 bit rates. Under a bandwidth of 160MHz, the number of subcarriers is 1960. According to the calculation formula of the data rate (the rate sent by the AP to the STA):

[0074]

[0075] Among them, N SD,U Indicates the number of subcarriers per RU, N BPSCS,U Indicates the number of codes per subcarrier per spatial stream per RU, R represents the code rate, N SS represents the number of spatial streams, T DFT Indicates the OFDM symbol length, T GI Indicates the length of the guard interval. The symbol length of OFDM is 12.8 microseconds, and the guard interval here is 0.8 microseconds. The data rate calculated is 2402Mbps, which is only the theoretical maximum value and does not take into account the redundant overhead such as the training sequence included in the PPDU frame format. Assuming that in this case the maximum downlink rate of Wi-Fi is basically matched with the downlink rate of PON, a common buffer size of 2-4MB is selected, and there will be no buffer overflow.

[0076] However, when the device is moving (such as when a person is walking with a mobile phone in hand) or there is interference from other devices in the Wi-Fi basic service set, the signal-to-noise interference ratio (SINR), a key indicator affecting the MCS, will decrease. This embodiment assumes that MCS selects 8 when interference is received, the spatial streams are still 2, the modulation mode is reduced to 256-QAM, the code rate is reduced to 3 / 4, the bandwidth is limited to 80MHz, and the protection interval time remains unchanged. The calculated data rate is 864.7Mbps. In this scenario, the downlink rate that Wi-Fi can transmit is much lower than the downlink rate from PON, and the mobile device's request for traffic will not be reduced due to the influence of channel interference. Therefore, a downlink transmission time slot allocation algorithm is required to prevent AP buffer data overflow.

[0077] The downstream traffic scheduler calculates the amount of data that can be transmitted in each step based on the AP's throughput prediction and the remaining information in the buffer area, and allocates the downstream transmission time slot of each ONU accordingly, thereby controlling the AP's downstream data buffer area and effectively preventing it from overflowing.

[0078] like Figure 4 As shown in the left figure, assuming that the 4MB buffer is initially empty, if this method is not used, the buffer will be full after 20 milliseconds, and the downlink data arriving thereafter will be discarded, causing an unbearable delay when the user requests again. Figure 4 The right figure in FIG. 1 uses the downlink transmission time slot allocation algorithm proposed by the present invention. It can be seen that the downlink data from the PON quickly fills up the buffer area in the first 20 milliseconds, but after 20 milliseconds, the proposed algorithm controls the downlink data in the OLT queue, so that the downlink data volume is released according to the set step size. Figure 4 In the right figure, y1 represents the amount of data transmitted from PON to AP, the solid line y2 represents the amount of data sent by AP to STA through the air interface, and y3 represents the maximum amount of data that the buffer can accommodate.

[0079] One of the reasons why this method can be implemented is that Wi-Fi, as a common access network, is usually used indoors, that is, people's movement speed is not too fast, so the scheduling period of 500ms is more reasonable and can also be adjusted according to actual needs. The time for uplink and downlink interaction in PON is microseconds. Considering the time overhead of information interaction, the final information interaction time is still much less than the scheduling period of 500 milliseconds. The present invention reduces the packet loss rate at Wi-Fi by adding some interaction overhead in Wi-Fi and PON, avoiding the unbearable delay caused by retransmission.

[0080] Embodiment 2

[0081] This embodiment provides a time slot allocation system for downlink transmission in an optical and wireless converged network, including:

[0082] Acquisition module: used to obtain the predicted throughput C sent by the wireless access point AP to the mobile station STA and the remaining amount B of the downlink data buffer area of ​​the wireless access point AP in the optical and wireless converged network;

[0083] A construction module: used to construct a downlink transmission time slot of an optical network unit ONU according to the predicted throughput C and the remaining amount B of the downlink data buffer area of ​​the wireless access point AP, wherein each of the optical network units ONU is connected to a wireless access point AP;

[0084] Time slot allocation module: used to compare the constructed optical network unit ONU's downlink transmission time slot with the original optical network unit ONU's downlink transmission time slot in the optical and wireless converged network, and take the smaller value as the final optical network unit ONU's downlink transmission time slot.

[0085] Embodiment 3

[0086] This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method for allocating time slots for downlink transmission in an optical and wireless converged network described in Embodiment 1 are implemented.

[0087] Embodiment 4

[0088] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for allocating time slots for downlink transmission in an optical and wireless converged network described in the first embodiment are implemented.

[0089] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of complete hardware embodiment, complete software embodiment, or the embodiment in combination with software and hardware. Moreover, the present application can adopt the form of the computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiment of the present application can adopt various computer languages ​​to realize, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0090] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0091] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0092] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0093] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0094] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A method for allocating time slots for downlink transmission in an optical and wireless converged network, characterized in that: include: Step S1: in the optical and wireless converged network, obtaining the predicted throughput C sent by the wireless access point AP to the mobile station STA and the remaining amount B in the downlink data buffer area of ​​the wireless access point AP; The expression of the predicted throughput C in step S1 is: in, It indicates the predicted throughput of the wireless access controller for voice service. represents the predicted throughput of the wireless access controller for the video service access category, It indicates the predicted throughput of the wireless access controller with the access category of best effort transmission. It indicates the predicted throughput of the access category of background traffic in the wireless access controller; The expression of the remaining amount B of the downlink data buffer area of ​​the wireless access point AP in step S1 is: B=[B AC_VO B AC_VI B AC_BE B AC_BK ] Among them, B AC_VO Indicates the remaining amount of downlink data buffer in the wireless access controller with access category of voice service, B AC_VI Indicates the remaining amount of downlink data buffer in the wireless access controller with access category of video service, B AC_BE Indicates the remaining amount of downlink data buffer in the wireless access controller with the access category of best effort transmission, B AC_BK Indicates the remaining amount of downlink data buffer in the wireless access controller with access category as background traffic; Step S2: constructing a downlink transmission time slot of an optical network unit ONU according to the predicted throughput C and the remaining amount B of the downlink data buffer area of ​​the wireless access point AP, wherein each of the optical network units ONU is connected to a wireless access point AP; In the step S2, the downlink transmission time slot of the optical network unit ONU is constructed according to the predicted throughput C and the remaining amount B of the downlink data buffer area of ​​the wireless access point AP, and the method includes: The downlink data volume D of the ac-th AP access category of the i-th optical network unit ONU is constructed according to the predicted throughput C and the remaining amount B of the downlink data buffer area of ​​the wireless access point AP i,ac The conditional formula is optimized to obtain the downstream data volume D of the ac-th AP access category of the i-th optical network unit ONU i,ac The optimization formula of According to the downlink data volume D of the ac-th AP access category of the i-th optical network unit ONU i,ac The optimization formula is used to construct the downlink transmission time slot of the optical network unit ONU; The amount of downlink data D of the ac-th AP access category of the i-th optical network unit ONU i,ac The conditional formula is expressed as: Where, τ is the MAC layer interaction delay between AP and OLT, C i,ac is the throughput of the ac-th AP access category of the i-th ONU, B i,ac is the remaining size of the buffer of the ac-th AP access category of the i-th ONU, and T is the period of arrival of the MAC layer interaction information; The conditional formula is optimized to obtain the downstream data volume D of the ac-th AP access category of the i-th optical network unit ONU i,ac The optimization formula is expressed as: According to the downlink data volume D of the ac-th AP access category of the i-th optical network unit ONU i,ac The optimization formula of constructing the downlink transmission time slot of the optical network unit ONU includes: Set up a matrix A with N*AC elements all set to 1 N×AC ,The wireless access control server AC is an access classification for each wireless access point AP, including four: AC_VO, AC_VI, AC_BE, and AC_BK; In the period T, at the current time step, if the amount of data of ac classes sent to the i-th wireless access point AP satisfies the optimization formula, let the matrix A N×AC The corresponding element A in i,ac It still remains at 1, indicating that the buffer area in the corresponding wireless access point AP is not full, and the optical line terminal OLT is based on the corresponding element A i,ac If it still remains at 1, the optical line terminal OLT continues to send the data of the access category of the ac-th wireless access point AP to the i-th optical network unit ONU; In the period T, at the next time step, continue to determine whether the amount of data of the ac classes sent to the i-th wireless access point AP satisfies the optimization formula. If it does not satisfy the optimization formula, let the matrix A N×AC The corresponding element A in i,ac = 0, indicating that the cache area of ​​the ac class in the wireless access point AP is full, and the optical line terminal OLT is based on the corresponding element A i,ac If it is 0, the optical line terminal OLT is stopped from sending the data of the access category of the ac-th wireless access point AP to the i-th optical network unit ONU; when the accumulated time step reaches the period T, the loop is exited; The downlink transmission time slot sent by OLT to the i-th optical network unit ONU in period T is expressed as: Among them, Rate represents the rate of downstream transmission in the passive optical network; Step S3: compare the constructed downlink transmission time slot of the optical network unit ONU with the downlink transmission time slot of the original optical network unit ONU in the optical and wireless converged network, and take the smaller value as the final downlink transmission time slot of the optical network unit ONU.

2. A time slot allocation system for downlink transmission in an optical and wireless converged network, characterized in that: include: Acquisition module: used to obtain the predicted throughput C sent by the wireless access point AP to the mobile station STA and the remaining amount B of the downlink data buffer area of ​​the wireless access point AP in the optical and wireless converged network; The expression of the predicted throughput C in the acquisition module is: in, It indicates the predicted throughput of the wireless access controller for voice service. represents the predicted throughput of the wireless access controller for the video service access category, It indicates the predicted throughput of the wireless access controller with the access category of best effort transmission. It indicates the predicted throughput of the access category of background traffic in the wireless access controller; The expression of the remaining amount B of the downlink data buffer area of ​​the wireless access point AP in the acquisition module is: B=[B AC_VO B AC_VI B AC_BE B AC_BK ] Among them, B AC_VO Indicates the remaining amount of downlink data buffer in the wireless access controller with access category of voice service, B AC_VI Indicates the remaining amount of downlink data buffer in the wireless access controller with access category of video service, B AC_BE Indicates the remaining amount of downlink data buffer in the wireless access controller with the access category of best effort transmission, B AC_BK Indicates the remaining amount of downlink data buffer in the wireless access controller with access category as background traffic; A construction module: used to construct a downlink transmission time slot of an optical network unit ONU according to the predicted throughput C and the remaining amount B of the downlink data buffer area of ​​the wireless access point AP, wherein each of the optical network units ONU is connected to a wireless access point AP; In the construction module, a downlink transmission time slot of an optical network unit ONU is constructed according to the predicted throughput C and the remaining amount B of the downlink data buffer area of ​​the wireless access point AP, and the method includes: The downlink data volume D of the ac-th AP access category of the i-th optical network unit ONU is constructed according to the predicted throughput C and the remaining amount B of the downlink data buffer area of ​​the wireless access point AP i,ac The conditional formula is optimized to obtain the downstream data volume D of the ac-th AP access category of the i-th optical network unit ONU i,ac The optimization formula of According to the downlink data volume D of the ac-th AP access category of the i-th optical network unit ONU i，ac The optimization formula is used to construct the downlink transmission time slot of the optical network unit ONU; The amount of downlink data D of the ac-th AP access category of the i-th optical network unit ONU i，ac The conditional formula is expressed as: Where, T is the MAC layer interaction delay between AP and OLT, C i,ac is the throughput of the ac-th AP access category of the i-th ONU, B i,ac is the remaining size of the buffer of the ac-th AP access category of the i-th ONU, and T is the period of arrival of the MAC layer interaction information; The conditional formula is optimized to obtain the downstream data volume D of the ac-th AP access category of the i-th optical network unit ONU i，ac The optimization formula is expressed as: D i，ac ≤(t+τ)C i,ac +B i,ac ,Vt∈[0,T] According to the downlink data volume D of the ac-th AP access category of the i-th optical network unit ONU i，ac The optimization formula of constructing the downlink transmission time slot of the optical network unit ONU includes: Set up a matrix A with N*AC elements all set to 1 N×AC ,The wireless access control server AC is an access classification for each wireless access point AP, including AC_V0, AC_VI, AC_BE, and AC_BK; In the period T, at the current time step, if the amount of data of ac classes sent to the i-th wireless access point AP satisfies the optimization formula, let the matrix A N×AC The corresponding element A in i，ac Still maintains 1, indicating that the buffer area in the corresponding wireless access point AP is not full, and the optical line terminal OLT is based on the corresponding element A i，ac If it remains at 1, the optical line terminal OLT continues to send data of the ac-th wireless access point AP access category to the i-th optical network unit ONU; In the period T, at the next time step, continue to determine whether the amount of data of the ac classes sent to the i-th wireless access point AP satisfies the optimization formula. If it does not satisfy the optimization formula, let the matrix A N×AC The corresponding element A in i，ac = 0, indicating that the cache area of ​​the ac class in the wireless access point AP is full, and the optical line terminal OLT is based on the corresponding element A i,ac If it is 0, the optical line terminal OLT is stopped from sending the data of the access category of the ac-th wireless access point AP to the i-th optical network unit ONU; when the accumulated time step reaches the period T, the loop is exited; The downlink transmission time slot sent by OLT to the i-th optical network unit ONU in period T is expressed as: Among them, Rate represents the rate of downstream transmission in the passive optical network; Time slot allocation module: used to compare the constructed optical network unit ONU's downlink transmission time slot with the original optical network unit ONU's downlink transmission time slot in the optical and wireless converged network, and take the smaller value as the final optical network unit ONU's downlink transmission time slot.

3. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method for allocating time slots for downlink transmission in an optical and wireless converged network as claimed in claim 1 are implemented.

4. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for allocating time slots for downlink transmission in an optical and wireless converged network as claimed in claim 1 are implemented.

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