Resource allocation method in centralized optical and wireless access network

Abstract

The invention relates to the technical field of centralized optical and wireless access networks, and discloses a resource allocation method in a centralized optical and wireless access network, which only acquires a cache state report of a time delay sensitive user which is successfully reported, and preferentially allocates optical and wireless resources to the time delay sensitive user; under the condition that the time delay sensitive users are preferential, the expected number of RUs and the initial number of the RUs of each TS user are calculated, the Scheduled RUs are redistributed, and after the actual number of the RUs of each TS user is obtained, the optical transmission rate and the wireless transmission rate corresponding to each TS user are calculated; according to the method, different sizes of RUs and corresponding photon carriers are flexibly allocated to the time delay sensitive users, so that different requirements of the time delay sensitive users are accurately met, and the resource utilization rate is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of centralized optical and wireless access networks, and in particular to a resource allocation method in a centralized optical and wireless access network. Background Art

[0002] Broadband services in home networks have strict requirements for large bandwidth and low latency. At present, since a single access point (AP) cannot cover multiple rooms, the quality of Wi-Fi has become an important factor restricting the quality of home broadband. Therefore, network performance is improved by networking multiple APs. Extending fiber to the room (Fibre-to-the-room, FTTR) is the main solution for the whole house gigabit experience. Among them, the integration of passive optical network (Passive optical network, PON) and Wi-Fi is an important network technology for realizing FTTR. In the FTTR scenario, the centralized optical and wireless access network architecture (Centralized Wi-Fi access network, C-WAN) can achieve centralized management and control and support collaboration between PON and Wi-Fi. In the C-WAN architecture, the orthogonal frequency division multiplexing passive optical network (OFDM-PON) is an effective solution to support C-WAN fronthaul due to its moderate cost, flexible subcarrier granularity and low latency. In the OFDM-PON-based C-WAN architecture, how to design a collaborative resource allocation mechanism between optical and Wi-Fi to meet the needs of different broadband services in FTTR scenarios requires further research.

[0003] The existing OFDM-PON-based C-WAN architecture adopts a Wi-Fi access protocol based on multi-user parallel transmission based on trigger frames. The protocol process is as follows: the main FTTR unit (Main fiber unit, MFU) sends a trigger frame, which contains knowledge information related to resource allocation, including the number of wireless resource units (Resource Unit, RU) used for random competition and the transmission duration. After the user (Station, STA) receives the trigger frame and obtains the relevant resource allocation information, it randomly selects an RU to transmit its own data through competition. When there are many users participating in the competition, collisions may occur, resulting in transmission failure.

[0004] The current OFDM-PON-based C-WAN protocol does not distinguish between service types. All types of users (STAs) in the same room’s sub-fiber unit (SFU) compete for wireless resources together, and all allocated wireless resource units (RUs) have the same size and duration, with zero padding for data frames with shorter transmission time. Figure 1As shown in the figure, it is a schematic diagram of synchronous transmission inside SFU. In addition, the current protocol and resource allocation scheme considers complete synchronization between all rooms. To maintain synchronization between FTTR units (Sub Fiber Unit, SFU) in different rooms, it is also necessary to fill zeros for data frames with shorter transmission time; Figure 2 As shown in FIG. 1 , it is a schematic diagram of synchronous transmission between SFUs; thus, a large waste of resources is caused, and the time waiting for alignment will also affect the performance such as access delay and jitter.

[0005] In summary, in the OFDM-PON-based C-WAN architecture, the existing optical and wireless collaborative resource allocation algorithm does not distinguish between service priorities and cannot guarantee the TS requirements of delay-sensitive services. In addition, all users are allocated the same RU size, which cannot meet the network requirements of different service types. The strategy is completely synchronized within the SFU and between different SFUs, that is, all start and end transmission at the same time. To maintain synchronization, data frames with short transmission time need to be padded with zeros to align the transmission time, resulting in a huge waste of optical and wireless resources. Summary of the invention

[0006] Therefore, the technical problem to be solved by the present invention is to overcome the problem that the prior art does not consider service delay sensitivity and allocates the same resources to all users, resulting in resource waste and transmission delay.

[0007] In order to solve the above technical problems, the present invention provides a method for allocating resources in a centralized optical and wireless access network, which is applied to each room in the centralized optical and wireless access network, and comprises:

[0008] Based on the cache status report of the TS user who successfully reported, the bandwidth requirements of the TS users in the room are obtained, the total wireless transmission capacity and total optical transmission capacity required by the TS users in the room are calculated, and the wireless channel width of the room is obtained;

[0009] Based on the wireless channel width and the ratio of the bandwidth requirement of each TS user to the total bandwidth requirement of the room, calculate the expected number of Schedule RUs for each TS user in the room;

[0010] Based on the expected number of RUs of each TS user and the number of wireless subcarriers in each Schedule RU, obtain the initial number of RUs allocated to each TS user in the room;

[0011] Based on the expected number of RUs and the initial number of RUs for each TS user, the scheduled RUs are reallocated to obtain the actual number of RUs for each TS user.

[0012] Based on the number of wireless subcarriers in each Scheduled RU, obtain the wireless transmission rate corresponding to the TS user;

[0013] Based on the actual number of RUs of each TS user and the number of wireless subcarriers in each scheduled RU, the number of optical subcarriers required to transmit the data of each TS user is calculated. Combined with the transmission rate of a single optical subcarrier, the optical transmission rate corresponding to each TS user is calculated.

[0014] Based on the bandwidth requirement of each TS user and the wireless transmission rate and optical transmission rate corresponding to each TS user, the wireless transmission time and optical transmission time of each TS user are calculated;

[0015] Resources are allocated based on the number of optical subcarriers, wireless transmission time, optical transmission time and preset Random RU transmission duration corresponding to each user.

[0016] Preferably, obtaining the cache status report of the TS user who successfully reported includes:

[0017] The MFU sends a cache status report polling frame to request cache status reports from all TS users;

[0018] After receiving the buffer status report polling frame, each TS user obtains the RU information that can be used for random contention access, and uses the uplink OFDMA random access mechanism to randomly select an RU to upload the buffer status report:

[0019] If the RU is selected by only one TS user, the cache status report of the TS user is successful;

[0020] If the RU is selected by multiple TS users, the cache status reports of the multiple TS users that selected the RU fail to be reported.

[0021] Preferably, calculating the total wireless transmission capacity and the total optical transmission capacity required by TS users in the room and obtaining the wireless channel width of the room includes:

[0022] Based on the total number of supported users N in each room and the bandwidth requirements of TS users in each room, the total wireless transmission capacity required by TS users in each room is calculated, which is expressed as:

[0023]

[0024] Based on the total wireless transmission capacity required by TS users in all rooms, obtain the minimum available capacity to meet the needs of each room It is expressed as:

[0025] Based on the minimum available capacity of all rooms As well as the total capacity of the OFDM passive optical network, calculate the total optical transmission capacity required by TS users in each room It is expressed as:

[0026]

[0027] Adjust the minimum available capacity to meet the needs of TS users in each room make

[0028] Based on the minimum available capacity to meet the TS user needs in each room The preset relationship table with the wireless channel width obtains the wireless channel width B corresponding to the TS user in each room i ;

[0029] in, represents the total wireless transmission capacity required by TS users in the i-th room, represents the bandwidth requirement of the jth TS STA in the i-th room, T i ′ represents the data transmission time of the i-th room in the previous round; M represents the total number of rooms supported by the centralized optical and wireless access network.

[0030] Preferably, based on the wireless channel width and the ratio of the bandwidth requirement of each TS user to the total bandwidth requirement of the room, the expected number of Schedule RUs for each TS user in the room is calculated, expressed as:

[0031]

[0032] in, represents the expected number of RUs of the jth TS STA in the i-th room, Indicates that the wireless channel width is B i The total number of RUs that can be supported; represents the bandwidth requirement of the jth TS STA in the ith room, and N represents the total number of users supported in each room.

[0033] Preferably, based on the expected number of RUs of each TS user and the number of wireless subcarriers in each Schedule RU, the initial number of RUs allocated to each TS user in the room is obtained, including:

[0034] Based on the expected number of RUs for the jth TS user in the i-th room Calculate the RU granularity value l of the jth TS user in the i-th room i,j , expressed as:

[0035] Calculate l of 2 i,j To obtain the initial RU number A allocated to the jth TS user in the i-th room i,j , expressed as:

[0036] Preferably, the scheduled RUs are reallocated based on the expected number of RUs and the initial number of RUs of each TS user, including:

[0037] Based on the wireless channel width and the initial number of RUs of each TS user, the total number of remaining RUs in the room is calculated, expressed as:

[0038] Calculate the difference between the expected number of RUs and the initial number of RUs for each TS user, and obtain the number of RUs to be satisfied for each TS user, expressed as:

[0039] In each room, the number of RUs to be satisfied of all TS users in the room is sorted in descending order, and based on the sorted TS users, the number of RUs to be satisfied of the TS users is calculated in order. i,j The total number of remaining RUs in the room For comparison:

[0040] like Then, the Scheduled RU is allocated to the TS user, and the total number of remaining RUs in the room is updated;

[0041] like The demand of the TS user cannot be met, and the number of RUs to be met for the next TS user is compared. i,j The total number of remaining RUs in the room

[0042] The scheduled RUs are redistributed until the total number of remaining RUs in the room reaches 0.

[0043] Preferably, based on the number of wireless subcarriers in each Scheduled RU, the wireless transmission rate corresponding to the TS user is obtained, which is expressed as:

[0044]

[0045] in, represents the wireless transmission rate of the jth TS user in the i-th room, N SS Represents the number of spatial streams; A i,j represents the actual number of RUs allocated to the jth TS user in the i-th room, x represents the number of subcarriers contained in the RU, and A i,j*x represents the total number of subcarriers allocated to a TS user; N BPSCS,U represents the modulation order, R C Indicates the bit rate; T DFT Indicates the OFDM symbol length, T GI Indicates the symbol interval.

[0046] Preferably, based on the actual number of RUs of each TS user and the number of wireless subcarriers in each Scheduled RU, the number of optical subcarriers required to transmit data in each TS user is calculated, and combined with the transmission rate of a single optical subcarrier, the optical transmission rate corresponding to each TS user is calculated, including:

[0047] Based on the actual number of RUs for each TS user and the number of radio subcarriers in each Scheduled RU, the number of optical subcarriers required to transmit the data in each TS user is calculated, expressed as:

[0048]

[0049] Based on the number of optical subcarriers required to transmit the data in each TS user and the transmission rate of a single optical subcarrier, the optical transmission rate corresponding to each TS user is calculated and expressed as:

[0050]

[0051] in, represents the number of optical subcarriers required by the jth TS user in the i-th room, A i,j represents the actual number of RUs allocated to the jth TS user in the i-th room, ρ represents the number of optical subcarriers required for the capacity provided by the wireless subcarrier of a scheduled RU, represents the optical transmission rate of the jth TS user in the ith room, and r represents the transmission rate of a single optical subcarrier.

[0052] Preferably, the acquisition of the preset Random RU transmission duration includes:

[0053] Get the number of RUs remaining in the channel after the scheduled RU allocation is completed, and use them as random RUs to allocate to TS users and NTS users who have not reported successfully.

[0054] Calculate the number of optical subcarriers, wireless transmission rate, and optical transmission rate required by each user corresponding to the Random RU;

[0055] Based on the bandwidth requirements of each user and the wireless transmission rate and optical transmission rate corresponding to each user, the wireless transmission time and optical transmission time of each user are calculated, and combined with the transmission time of the frame in the network, the Random RU transmission duration is obtained.

[0056] Preferably, calculating the number of optical subcarriers, the wireless transmission rate, and the optical transmission rate required by each user corresponding to the Random RU includes:

[0057] Calculate the number of Random RUs in the i-th room based on the wireless channel width corresponding to the i-th room and the maximum bandwidth of the wireless channel It is expressed as:

[0058]

[0059] Based on the total number of Random RUs in all rooms The total number of optical subcarriers used for scheduling access is calculated by the number of optical subcarriers required for each RU capacity, ρ It is expressed as:

[0060] Based on the total number of Schedule RUs in all rooms The total number of optical subcarriers used for random access is calculated by comparing the number of optical subcarriers required for each RU capacity, ρ. It is expressed as:

[0061] Compare whether the number of remaining photocarriers in the OFDM passive optical network, except for the photocarriers used for scheduling access, meets the total number of photocarriers used for random access:

[0062] like The remaining optical subcarriers are then allocated to users as needed;

[0063] like The remaining optical subcarriers are allocated to users in proportion; when the proportion is allocated, the number of optical subcarriers allocated to each user is

[0064] Based on the number of wireless subcarriers in each Schedule RU, the wireless transmission rate corresponding to the user is obtained; based on the actual number of RUs of each user and the number of wireless subcarriers in each Schedule RU, the number of optical subcarriers required to transmit the data of each user is calculated, and combined with the transmission rate of a single optical subcarrier, the optical transmission rate corresponding to the user is calculated;

[0065] in, Indicates the total number of RUs that can be supported when the wireless channel width is B; Indicates that the wireless channel width is B i When , the total number of RUs that can be supported; M represents the total number of rooms supported in the centralized optical and wireless access network, and N represents the total number of users supported in each room; A i,j represents the actual number of RUs allocated to the jth TS user in the i-th room, represents the number of Random RUs used for random access in the i-th room; U represents the total number of subcarriers in the orthogonal frequency division multiplexing passive optical network.

[0066] Preferably, based on the bandwidth requirement of each user and the wireless transmission rate and optical transmission rate corresponding to each user, the wireless transmission time and optical transmission time of each user are calculated, and combined with the transmission time of the frame in the network, the RandomRU transmission duration is obtained, including:

[0067] Based on the bandwidth requirement of the jth TS user in the i-th room The corresponding wireless transmission rate Calculate the wireless transmission time of the jth TS user in the i-th room It is expressed as:

[0068] Bandwidth requirement of the jth TS user in each i-th room The corresponding optical transmission rate Calculate the optical transmission time of the jth TS user in the i-th room It is expressed as:

[0069] The maximum wireless transmission time of all TS users in the i-th room Maximum light transmission time and cache status report transmission time T BSR , trigger frame transmission time T TF , processing time T Process , Time required to confirm the frame T ACK and the short interframe spacing time SIFS, calculate the maximum transmission duration T i And the maximum transmission time is used as the RandomRU transmission duration, expressed as:

[0070]

[0071] in,

[0072] Preferably, after obtaining the number of optical subcarriers, wireless transmission time, optical transmission time and RandomRU transmission duration corresponding to each user, it also includes:

[0073] Enables synchronous transmission between different users in the same room;

[0074] Between different rooms, during the transmission process of users with long transmission time, users with short transmission time are allowed to perform multiple rounds of transmission;

[0075] The transmission time T required for a new round of transmission by a user with short transmission time i ″, expressed as:

[0076] like A new round of transmission cannot be performed;

[0077] like A new round of transmission is then performed and the maximum remaining time is updated

[0078] in, Represents the maximum transmission time of a user, expressed as T i Indicates the maximum transfer duration.

[0079] The above technical solution of the present invention has the following beneficial effects compared with the prior art:

[0080] The resource allocation method in the centralized optical and wireless access network described in the present invention only obtains the cache status report of the delay-sensitive user who has successfully reported, and allocates optical and wireless resources to the delay-sensitive users first; when the delay-sensitive users are given priority, RU is initially allocated and reallocated for each user based on the bandwidth demand corresponding to the user, and the optical subcarrier is matched at the same time. By flexibly allocating RUs of different sizes and corresponding optical subcarriers to the delay-sensitive users, the different needs of the delay-sensitive users are accurately met, and the resource utilization rate is greatly improved.

[0081] During the reporting phase, the present invention only allows delay-sensitive (TS) users to report cache status reports. By limiting the competition of non-delay-sensitive (NTS) users, the probability of successful reporting by delay-sensitive users is greatly improved, so that optical and wireless resources can be allocated to delay-sensitive users in priority in the future, effectively reducing the access delay of delay-sensitive users.

[0082] The present invention adopts a strategy of synchronization within the room and asynchrony between rooms. During the transmission process in the room with a long transmission time, multiple rounds of transmission are allowed in the room with a short transmission time, thereby reducing the resource waste caused by zero padding for synchronization alignment, effectively reducing the access delay and jitter of delay-sensitive services, and significantly improving resource utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0084] Figure 1 This is a schematic diagram of internal synchronous transmission in SFU;

[0085] Figure 2 It is a schematic diagram of synchronous transmission between SFUs;

[0086] Figure 3 It is a flow chart of the steps of the resource allocation method in the centralized optical and wireless access network provided by the present invention;

[0087] Figure 4 A flow chart of a priority-based access protocol for delay-sensitive services provided by the present invention;

[0088] Figure 5 Schematic diagram of the reporting process for TS users;

[0089] Figure 6 It is a schematic diagram of asynchrony between SFUs;

[0090] Figure 7 (a) is a schematic diagram showing the comparison of access delays of the present invention and the comparative solution. Figure 7 (b) is a schematic diagram showing the comparison results of access jitter between the present invention and the comparative solution. Figure 7 (c) is a schematic diagram showing the comparison results of wireless resource utilization between the present invention and the comparative solution. DETAILED DESCRIPTION

[0091] 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.

[0092] Reference Figure 3 As shown, the step flow chart of the resource allocation method in the centralized optical and wireless access network provided by the present invention is applied to each room in the centralized optical and wireless access network, including:

[0093] S101: based on the cache status report of the TS user who successfully reported, the bandwidth demand of the TS user in the room is obtained, the total wireless transmission capacity and the total optical transmission capacity required by the TS user in the room are calculated, and the wireless channel width of the room is obtained;

[0094] S102: Calculate the expected number of Schedule RUs for each TS user in the room based on the wireless channel width and the ratio of the bandwidth demand of each TS user to the total bandwidth demand of the room;

[0095] S103: based on the expected number of RUs of each TS user and the number of wireless subcarriers in each Schedule RU, obtain the initial number of RUs of Schedule RUs allocated to each TS user in the room;

[0096] S104: based on the expected number of RUs and the initial number of RUs of each TS user, the scheduled RUs are reallocated to obtain the actual number of RUs of each TS user;

[0097] S105: based on the number of wireless subcarriers in each Scheduled RU, obtain the wireless transmission rate corresponding to the TS user;

[0098] S106: Based on the actual number of RUs of each TS user and the number of wireless subcarriers in each Scheduled RU, the number of optical subcarriers required to transmit data in each TS user is calculated, and the optical transmission rate corresponding to each TS user is calculated in combination with the transmission rate of a single optical subcarrier;

[0099] S107: Calculate the wireless transmission time and optical transmission time of each TS user based on the bandwidth requirement of each TS user and the wireless transmission rate and optical transmission rate corresponding to each TS user;

[0100] S108: Allocate resources based on the number of optical subcarriers, wireless transmission time, optical transmission time and preset Random RU transmission duration corresponding to each user.

[0101] Specifically, in step S101, obtaining the cache status report of the TS user that has successfully reported includes:

[0102] The MFU sends a cache status report polling frame to request cache status reports from all TS users;

[0103] After receiving the buffer status report polling frame, each TS user obtains the RU information that can be used for random contention access, and uses the uplink OFDMA random access mechanism to randomly select an RU to upload the buffer status report:

[0104] If the RU is selected by only one TS user, the cache status report of the TS user is successful;

[0105] If the RU is selected by multiple TS users, the cache status reports of the multiple TS users that selected the RU fail to be reported.

[0106] During the reporting phase, the present invention only allows delay-sensitive (TS) users to report cache status reports. By limiting the competition of non-delay-sensitive (NTS) users, the probability of successful reporting by delay-sensitive users is greatly improved, so that optical and wireless resources can be allocated to delay-sensitive users in priority in the future, effectively reducing the access delay of delay-sensitive users.

[0107] Specifically, in step S101, the total wireless transmission capacity and the total optical transmission capacity required by the TS users in the room are calculated, and the wireless channel width of the room is obtained, including:

[0108] S101-1: Based on the total number of supported users N in each room and the bandwidth requirements of the TS users in each room, the total wireless transmission capacity required by the TS users in each room is calculated, which is expressed as:

[0109]

[0110] S101-2: Based on the total wireless transmission capacity required by TS users in all rooms, obtain the minimum available capacity that meets the needs of each room It is expressed as:

[0111] S101-3: Based on the minimum available capacity of all rooms As well as the total capacity of the OFDM passive optical network, calculate the total optical transmission capacity required by TS users in each room It is expressed as:

[0112]

[0113] S101-4: Adjust the minimum available capacity to meet the needs of TS users in each room make

[0114] S101-5: Minimum available capacity based on meeting TS user needs in each room The preset relationship table with the wireless channel width obtains the wireless channel width B corresponding to the TS user in each room i ;

[0115] in, represents the total wireless transmission capacity required by TS users in the i-th room, represents the bandwidth requirement of the jth TS STA in the i-th room, T i ′ represents the data transmission time of the i-th room in the previous round; M represents the total number of rooms supported by the centralized optical and wireless access network.

[0116] Specifically, in step S102, the expected number of Schedule RUs for each TS user in the room is calculated, which is expressed as:

[0117] in, represents the expected number of RUs of the jth TS STA in the i-th room, Indicates that the wireless channel width is B i The total number of RUs that can be supported; represents the bandwidth requirement of the jth TS STA in the ith room, and N represents the total number of users supported in each room.

[0118] Specifically, in step S103, the initial number of Schedule RUs allocated to each TS user in the room is obtained, including:

[0119] Based on the expected number of RUs for the jth TS user in the i-th room Calculate the RU granularity value l of the jth TS user in the i-th room i,j , expressed as:

[0120] Calculate l of 2 i,j To obtain the initial RU number A allocated to the jth TS user in the i-th room i,j , expressed as:

[0121] Specifically, in step S104, the scheduled RUs are reallocated based on the expected number of RUs and the initial number of RUs of each TS user, including:

[0122] Based on the wireless channel width and the initial number of RUs of each TS user, the total number of remaining RUs in the room is calculated, expressed as:

[0123] Calculate the difference between the expected number of RUs and the initial number of RUs for each TS user, and obtain the number of RUs to be satisfied for each TS user, expressed as:

[0124] In each room, the number of RUs to be satisfied of all TS users in the room is sorted in descending order, and based on the sorted TS users, the number of RUs to be satisfied of the TS users is calculated in order. i,j The total number of remaining RUs in the room For comparison:

[0125] like Then, the Scheduled RU is allocated to the TS user, and the total number of remaining RUs in the room is updated;

[0126] like The demand of the TS user cannot be met, and the number of RUs to be met for the next TS user is compared. i,j The total number of remaining RUs in the room

[0127] The scheduled RUs are redistributed until the total number of remaining RUs in the room reaches 0.

[0128] Specifically, in step S105, based on the number of wireless subcarriers in each Scheduled RU, the wireless transmission rate corresponding to the TS user is obtained, which is expressed as:

[0129]

[0130] in, represents the wireless transmission rate of the jth TS user in the i-th room, N SS Represents the number of spatial streams; A i,j represents the actual number of RUs allocated to the jth TS user in the i-th room, x represents the number of subcarriers contained in the RU, and A i,j *x represents the total number of subcarriers allocated to a TS user; N BPSCS,U represents the modulation order, R C Indicates the bit rate; T DFT Indicates the OFDM symbol length, T GI Indicates the symbol interval.

[0131] Specifically, in step S106, the optical transmission rate corresponding to each TS user is calculated, including:

[0132] Based on the actual number of RUs for each TS user and the number of radio subcarriers in each Scheduled RU, the number of optical subcarriers required to transmit the data in each TS user is calculated, expressed as:

[0133]

[0134] Based on the number of optical subcarriers required to transmit the data in each TS user and the transmission rate of a single optical subcarrier, the optical transmission rate corresponding to each TS user is calculated and expressed as:

[0135] in, represents the number of optical subcarriers required by the jth TS user in the i-th room, A i,j represents the actual number of RUs allocated to the jth TS user in the i-th room, ρ represents the number of optical subcarriers required for the capacity provided by the wireless subcarrier of a scheduled RU, represents the optical transmission rate of the jth TS user in the ith room, and r represents the transmission rate of a single optical subcarrier.

[0136] In this embodiment, after allocating the Scheduled RU, the following steps are also included:

[0137] Get the number of RUs remaining in the channel after the scheduled RU allocation is completed, and use them as random RUs to allocate to TS users and NTS users who have not reported successfully.

[0138] Calculate the number of optical subcarriers, wireless transmission rate, and optical transmission rate required by each user corresponding to the Random RU;

[0139] Based on the bandwidth requirements of each user and the wireless transmission rate and optical transmission rate corresponding to each user, the wireless transmission time and optical transmission time of each user are calculated, and combined with the transmission time of the frame in the network, the Random RU transmission duration is obtained.

[0140] Specifically, the number of optical subcarriers, wireless transmission rate, and optical transmission rate required by each user corresponding to the Random RU are calculated, including:

[0141] Calculate the number of Random RUs in the i-th room based on the wireless channel width corresponding to the i-th room and the maximum bandwidth of the wireless channel It is expressed as:

[0142] Based on the total number of Random RUs in all rooms The total number of optical subcarriers used for scheduling access is calculated by the number of optical subcarriers required for each RU capacity, ρ It is expressed as:

[0143] Based on the total number of Schedule RUs in all rooms The total number of optical subcarriers used for random access is calculated by comparing the number of optical subcarriers required for each RU capacity, ρ. It is expressed as:

[0144] Compare whether the number of remaining photocarriers in the OFDM passive optical network, except for the photocarriers used for scheduling access, meets the total number of photocarriers used for random access:

[0145] like The remaining optical subcarriers are then allocated to users as needed;

[0146] like The remaining optical subcarriers are allocated to users in proportion; when the proportion is allocated, the number of optical subcarriers allocated to each user is

[0147] Based on the number of wireless subcarriers in each Schedule RU, the wireless transmission rate corresponding to the user is obtained; based on the actual number of RUs of each user and the number of wireless subcarriers in each Schedule RU, the number of optical subcarriers required to transmit the data of each user is calculated, and combined with the transmission rate of a single optical subcarrier, the optical transmission rate corresponding to the user is calculated;

[0148] in, Indicates the total number of RUs that can be supported when the wireless channel width is B; Indicates that the wireless channel width is B i When , the total number of RUs that can be supported; M represents the total number of rooms supported in the centralized optical and wireless access network, and N represents the total number of users supported in each room; A i,j represents the actual number of RUs allocated to the jth TS user in the i-th room, represents the number of Random RUs used for random access in the i-th room; U represents the total number of subcarriers in the orthogonal frequency division multiplexing passive optical network.

[0149] Specifically, obtain the Random RU transmission duration, including:

[0150] Based on the bandwidth requirement of the jth TS user in the i-th room The corresponding wireless transmission rate Calculate the wireless transmission time of the jth TS user in the i-th room It is expressed as:

[0151] Bandwidth requirement of the jth TS user in each i-th room The corresponding optical transmission rate Calculate the optical transmission time of the jth TS user in the i-th room It is expressed as:

[0152] The maximum wireless transmission time of all TS users in the i-th room Maximum light transmission time and cache status report transmission time T BSR , trigger frame transmission time T TF , processing time T Process , Time required to confirm the frame T ACKand the short interframe spacing time SIFS, calculate the maximum transmission duration T i And the maximum transmission time is used as the RandomRU transmission duration, expressed as:

[0153]

[0154] in,

[0155] In this embodiment, after the Schedule RU and the Random RU are allocated, the following steps are also included:

[0156] Enables synchronous transmission between different users in the same room;

[0157] Between different rooms, during the transmission process of users with long transmission time, users with short transmission time are allowed to perform multiple rounds of transmission;

[0158] The transmission time T required for a new round of transmission by a user with short transmission time i ″, expressed as:

[0159] like A new round of transmission cannot be performed;

[0160] like A new round of transmission is then performed and the maximum remaining time is updated

[0161] in, Represents the maximum transmission time of a user, expressed as T i Indicates the maximum transfer duration.

[0162] The present invention adopts a strategy of synchronization within the room and asynchrony between rooms. During the transmission process in the room with a long transmission time, multiple rounds of transmission are allowed in the room with a short transmission time, thereby reducing the resource waste caused by zero padding for synchronization alignment, effectively reducing the access delay and jitter of delay-sensitive services, and significantly improving resource utilization.

[0163] Based on the above embodiments, in an embodiment of the present invention, resource allocation is performed using the resource allocation method in a centralized optical and wireless access network proposed by the present invention, which can be specifically explained in two parts: one part is a priority-based access protocol for delay-sensitive services, which is used to obtain TS users who have reported successfully; the other part is a priority-based optical and wireless collaborative resource allocation algorithm.

[0164] 1. Priority-based access protocol for delay-sensitive services;

[0165] The embodiment of the present invention makes the following modifications to the original Wi-Fi access protocol based on buffer status report (BSR), including:

[0166] ① In the centralized C-WAN architecture, the buffer status report poll (BSRP) and trigger frame (TF) will contain the allocation information of optical subcarrier resources and wireless RUs; specifically, the size, number, and transmission time of RUs used for designated access and random access, as well as the number of optical subcarriers and transmission duration required to match the data transmitted by the RUs.

[0167] ② In the reporting phase, the BSRP frame contains indication information. When the TS STA receives the BSRP, it will respond and send its buffer status report BSR to the uplink. However, when the NTS STA receives the BSRP, it will not respond, will not participate in the competition in the reporting phase, and will not send the BSR to the uplink. In the reporting phase, only the TS STA is allowed to send its buffer status report BSR.

[0168] ③ In the data transmission phase, the media access control layer MAC at the main FTTR unit MFU allocates resources based on the information obtained in the reporting phase and saves the result of resource allocation in the frame header of the TF trigger frame.

[0169] All radio resource units are divided into two categories: one is RU for scheduled access, which is allocated to a specific TSSTA and has different sizes and transmission times according to the traffic demand of the TS STA; the other is RU for random access, which has the same size and transmission time and is used for users with unknown traffic demand information to compete. According to the allocation results of the radio RU resources, the number of optical subcarrier resources and the transmission time required are calculated.

[0170] Based on the above modifications, refer to Figure 4 As shown, it is a flow chart of the priority-based access protocol for delay-sensitive services provided by the present invention, which specifically includes:

[0171] ①Reporting stage:

[0172] In the downlink direction, the Wi-Fi MAC in the MFU sends BSRP frames to request TS STAs to report their buffer status reports BSP. At this time, NTS STAs cannot compete with TS STAs for wireless resources, so the probability of TS STAs successfully reporting their buffer status information can be increased.

[0173] In the uplink direction, when TS STAs receive the BSRP frame, they obtain the RU information that can be used for random contention access and use the Uplink OFDMA Random Access (UORA) mechanism to randomly select an RU to upload its cache status information.

[0174] Reference Figure 5 The figure shows a schematic diagram of the TS user reporting process; when multiple TS STAs select the same RU to report status information, a collision will occur, resulting in reporting failure.

[0175] ②Data transmission stage:

[0176] In the downlink direction, the WiFi-MAC in the MFU allocates optical and wireless resources using a priority-based optical and wireless collaborative resource allocation algorithm based on the bandwidth request information of TS STAs collected during the reporting phase.

[0177] Among them, the Wi-Fi MAC in the MFU collects the BSR frames of TS STAs. The BSR frames contain the cached data amount information, that is, the cache size; the Wi-Fi MAC in the MFU can determine the bandwidth request situation based on the cache size.

[0178] Among them, the allocated wireless RU resources are divided into two categories, one is the RU for scheduled access (Scheduled RUs), and the other is the RU for random access (Random RUs); Scheduled RUs dynamically allocate RUs of different sizes to TS STAs that successfully compete in the reporting phase according to the bandwidth request information. When allocating, they are specially designated to be allocated to the corresponding TS STAs according to the indication of the AID field in the TF, and no collision will occur. Random RU is the remaining RU except the RU specifically used for scheduling. It is used for random access of users with unknown status information, and there may be collisions. Among them, users with unknown status information include TS STAs that did not successfully compete in the first stage and did not report cache status information, as well as all NTS STAs.

[0179] According to the allocation results of RU, WiFi-MAC in MFU will also allocate the corresponding number of optical subcarriers to each SFU and calculate the transmission duration respectively. The results of the allocated optical and wireless resources are saved in the TF trigger frame. When the TF trigger frame sent by MFU MAC reaches SFU, SFU will adjust the subcarrier according to the optical subcarrier allocation information in the frame header of the trigger frame to facilitate the subsequent uplink data transmission. When the TF trigger frame further reaches the user STA, different types of STAs select the corresponding RU for wireless segment data transmission according to the indication information in the trigger frame.

[0180] In the uplink direction, the Wi-Fi physical layer data frames (Wi-Fi PHY frames) of each STA are transmitted in the wireless segment in the allocated RU. When the data frame reaches the SFU, it is first decapsulated into a Wi-Fi MAC frame, and then enters G.fin (the optical fiber indoor communication network between the MFU and the SFU) through the Ethernet access port. It is first encapsulated into a MAC frame at the MAC layer, and then encapsulated into a physical layer PHY frame, and then enters the OFDM-PON optical link for uplink transmission to the MFU. When the Wi-Fi MAC in the MFU successfully receives and parses the data sent by the user, it will send an ACK confirmation frame to the downlink.

[0181] 2. Priority-based optical and wireless collaborative resource allocation algorithm;

[0182] Based on the above embodiment, the embodiment of the present invention further provides a priority-based optical and wireless collaborative resource allocation algorithm. The Wi-Fi MAC in the MFU allocates optical and wireless resources to two types of users according to the cache status information of some TS STAs obtained in the reporting phase, sets the corresponding transmission duration, and saves the allocation information in the trigger frame. The specific allocation process includes:

[0183] S201. Selection of optical and wireless channel capacity for delay-sensitive services:

[0184] Wi-Fi 6 (802.11ax) supports multiple channel bandwidths to adapt to different network requirements. Choosing the right channel width depends on many factors, including the network's interference environment, bandwidth requirements, number of devices, traffic density, and the capacity of the fronthaul optical network.

[0185] Assume that M represents the number of room SFUs supported in the C-WAN architecture, and N represents the number of user STAs supported by the SFU in each room. According to the first reporting stage BSRP-BSR process, the bandwidth requirements of most TS STAs in each room can be obtained. Calculate the wireless transmission capacity for latency-sensitive services in each room It is expressed as:

[0186] in, Indicates the traffic size requested by the jth TS STA in the i-th room, in bits; T i ′ represents the transmission time of the i-th room in the previous cycle.

[0187] Therefore, according to the wireless channel width table, the current SFU can be obtained. Minimum capacity required The corresponding wireless channel width B i ,Require

[0188] Then calculate the OFDM-PON transmission capacity required for each SFU The OFDM-PON optical resources in each room need to be able to carry the data transmitted by the wireless channel to avoid the situation where the SFU receives the data from the STAs and fails to transmit, loses packets and waits for retransmission due to insufficient optical capacity. When the wireless capacity requirements of all SFUs are not greater than the total OFDM-PON capacity C, the capacity requested by the wireless part Allocate light capacity If it exceeds the limit, the light resources of each room will be allocated according to the proportion of traffic demand. Then adjust the wireless transmission capacity that can be carried by the optical capacity of each SFU. Ensure that the optical subcarrier allocated in the current SFU can carry all the data transmitted wirelessly, that is According to Table 1, the available wireless channel width B can be obtained. i .

[0189] Among them, the OFDM-PON transmission capacity required by each SFU It is expressed as:

[0190]

[0191] in, represents the minimum capacity that meets the needs of the i-th room, and C represents the total capacity of OFDM-PON.

[0192] Table 1 Wireless channel bandwidth and peak rate under single antenna

[0193]

[0194] Through the above process, it can be calculated that in the reporting phase, the total optical and wireless capacity required by most TS STAs in each SFU to successfully transmit cache status information is

[0195] S202, RU allocation of Wi-Fi segment:

[0196] S202-1: Scheduled RU initial allocation;

[0197] In IEEE 802.11ax (Wi-Fi 6), different channel widths can support different numbers and granularities of RUs, including 26-tone RU, 52-tone RU, 106-tone RU, 242-tone RU, 484-tone RU, and 996-tone RU. For the convenience of calculation, when the MCS and other conditions are the same, it can be approximately considered that the transmission rate of the Wi-Fi segment is only related to the RU size, and all RUs of different sizes can be regarded as a combination of multiple 26-tone RUs. In particular, a large RU can be regarded as composed of 2 small RUs, so each granularity of RU can be regarded as composed of 2 26-tone RUs.

[0198] In the initial stage, the bandwidth request of TS STAs users is Perform initial allocation according to the ratio and calculate the number of 26-tone RUs that the j-th TS STAs user in the i-th room expects to be allocated It is expressed as:

[0199] in, Indicates that the current room channel width is B i The total number of 26-tone RUs that can be supported. Indicates the number of 26-tone RUs that the user expects to obtain, but It may not meet the above RU specification requirements, so the calculation is less than or equal to The largest RU type that meets the specification requirements.

[0200] Assume that l represents the type of RU allocated to the user, l = 0 means that the RU type is 26-tone, and so on, l = 5 means that the RU type is 996-tone. 5 26-tone RUs. We can first calculate the number of RUs less than or equal to the jth user. Maximum RU type l i,j , thereby calculating the number of 26-tone RUs initially allocated A i,j , expressed as:

[0201] S202-2: Scheduled RU adjustment allocation:

[0202] After the initial allocation, when there are remaining 26-tone RUs, the allocation results are adjusted according to the size and number limit of each type of RU, and the allocation quantity of some users is gradually increased to ensure that the unlimited resources are used as fully as possible.

[0203] First calculate the total number of remaining unallocated 26-tone RUs And the difference D between the number of 26-tone RUs expected by each user and the number of 26-tone RUs initially allocated i,j , expressed as:

[0204]

[0205] In order to meet the quality of service (QoS) requirements of different users as much as possible, users with higher bandwidth requirements are given priority so that the number of resources allocated to them is closer to their expected number of resources. Therefore, the demand difference D i,j Sort in descending order; then adjust D i,j , put all TS STAs in front of NTS STAs in the allocation order, so that users with large bandwidth requirements in TS STA can be given priority. For the jth user who needs to continue to be allocated, the number of 26-tone RUs required is calculated as A i,j If the remaining total number of RUs is greater than the required total number of RUs, that is Then you can allocate as needed and adjust A i,i and Expressed as: A i,j =A i,j *2;

[0206] like This means that the remaining wireless resources cannot meet the needs of the current user, and then continue to determine whether the needs of the next user can be met.

[0207] Through the above method, the number of 26-tone RUs allocated to the scheduled access TS STAs can be finally obtained, and the number and position restrictions of RUs of different granularities can be met.

[0208] S202-3: Random RUs allocation:

[0209] When the scheduled RUs for scheduled access are allocated, all the remaining RUs in the Wi-Fi channel are used for random access of all other users. Since the buffer status reports of all other users are not obtained, i th The number of all 26-tone RUs used for random access in the room, expressed as:

[0210]

[0211] Where B represents the maximum bandwidth of the wireless channel, B i Indicates the maximum bandwidth required by TSSTAs to successfully report cache status information in the first phase.

[0212] S203, subcarrier allocation of OFDM-PON;

[0213] S203-1: For the Scheduled RUs for the specified allocation, the optical and wireless capacity selection for the TS STAs that successfully report the buffer status information in step S201 ensures that the optical subcarrier is sufficient to transmit the data carried by the Scheduled RUs. When the MCS setting is known, its wireless data transmission rate is also fixed, which is expressed as: Among them, N SS Represents the number of spatial streams, N BPSCS,U represents the modulation order, R C Indicates the bit rate, A i,j *26 indicates the number of subcarriers contained in one RU, T DFT Indicates the OFDM symbol length, T GI Indicates the symbol interval.

[0214] When the modulation information is determined, the data transmission rate of an RU is related to the number of subcarriers it contains. i,j Calculate the number of optical subcarriers required to transmit the data in the RU and data transfer rates It is expressed as: Where ρ is the number of optical subcarriers required for a 26-tone RU capacity; r is the data transmission rate of an optical subcarrier.

[0215] S203-2: For Random RUs used for random access, it is necessary to calculate whether the remaining optical subcarriers are sufficient to carry the data of all Random RUs.

[0216] Calculate the total number of RUs used for random access in all rooms, expressed as:

[0217] Calculate the total number of RUs used for scheduling access in all rooms, expressed as:

[0218] Therefore, the number of optical subcarriers corresponding to random access and scheduled access can be expressed as:

[0219] Assuming that the total number of subcarriers in OFDM-PON is U, if the system has enough subcarriers to meet the requirements of random access RU except for the subcarriers used for special scheduling, that is, Then just allocate as needed;

[0220] Otherwise, all remaining optical subcarriers need to be allocated to each SFU according to the expected ratio, expressed as: This in turn adjusts the number of 26-tone Random RUs that can be used for random access in the SFU. Calculate the rate of the RU and the rate of the corresponding required optical subcarrier group.

[0221] S204, optical and wireless transmission time:

[0222] S204-1: Synchronous transmission within SFU:

[0223] Due to the synchronization requirements of parallel transmission in the 802.11ax protocol, the data transmitted in parallel needs to start and end at the same time. If a TS STA reports successfully in the first phase of the SFU, the specific time required for optical and wireless transmission for each successful TS STA can be calculated, expressed as:

[0224]

[0225] The transmission duration of the room is taken as the maximum time required for a successful TS STA, which is also set to the transmission duration of Random RUs, expressed as:

[0226]

[0227]

[0228] Among them, T BSR Indicates the time required to transmit the buffer status report frame, T TF Indicates the time required to transmit the trigger frame, T Process Represents the total processing time of MFU and SFU, T ACK It indicates the time required to confirm a frame, and SIFS indicates the short inter-frame space time.

[0229] If no TS STA reports successfully in the first phase of the SFU, all RUs are used for random access, and the transmission duration of all RUs is set to a fixed value, expressed as: The transmission duration of all optical subcarriers will also be set to a fixed value, expressed as:

[0230] S204-2: Asynchronous between SFUs:

[0231] Reference Figure 6As shown, it is a schematic diagram of the asynchrony between SFUs. During the transmission process of SFUs with long transmission time, SFUs with a transmission time period are allowed to perform multiple rounds of transmission. The longest transmission time of all SFUs is:

[0232] When some SFUs complete the transmission of this round first, they can continue the next round of transmission. After the above scheduling process, the total time T required for the new round can be calculated. i ′, expressed as:

[0233]

[0234] If T i 'Exceeds the maximum remaining time of the previous round The transmission can then be continued according to the estimated time, and after the transmission is completed, it can be determined whether the next round of transmission can be performed.

[0235] In summary, the service priority-based access protocol of the present invention can increase the probability that users of delay-sensitive services report their cache status report frames, thereby allowing the subsequent resource allocation algorithm to perform optical and wireless resource allocation based on the obtained status information, giving priority to meeting the needs of delay-sensitive services. The optical and wireless collaborative resource allocation algorithm of the present invention can flexibly allocate RUs of different sizes and corresponding optical subcarriers to users of delay-sensitive services to meet the different needs of delay-sensitive services; at the same time, a strategy of synchronization within the room and asynchrony between rooms is adopted, allowing multiple rounds of transmission in rooms with short transmission times during transmission in rooms with long transmission times, thereby reducing the waste of resources caused by zero padding for synchronization alignment.

[0236] In order to verify the performance of the resource allocation algorithm based on the proposed protocol, this case was simulated on PYTHON. In the simulation, the uplink and downlink rates of OFDM-PON were 10Gb / s respectively, and the distance between the optical line terminal (OLT) (i.e., M-FIN) and each optical network unit (ONU) (i.e., S-FIN) was within 100 meters.

[0237] One SFU is configured in each room, and it is assumed that there is no wireless interference between these SFUs. In the wireless part, the distance between SFU and STA is within 10 meters. The wireless channel bandwidth of an SFU is 160MHz, supporting up to 74 26-tone RUs, and the data rate supported by each 26-tone RU is 11.1Mbit / s. Each STA generates data frames according to Poisson distribution, with an arrival rate of 200 frames per second. The size of each data frame arriving at TS and NTS STAs is 200 bytes and 1500 bytes respectively.

[0238] In the uplink process, after the physical layer frame of Wi-Fi reaches SFU, it is decapsulated into MAC frame, and then enters S-FTR through Ethernet interface, first encapsulated into FEM frame, then encapsulated into PON MAC frame by MAC layer, and then further encapsulated into physical frame to enter optical link for uplink transmission. The overhead in this process includes the overhead of data frame encapsulation, forward error correction coding of physical layer, cyclic prefix and preamble overhead. OFDM-PON system is configured with 1024 subcarriers, each with a rate of 9.7Mbit / s; considering the above overhead, 2 optical subcarriers are sufficient to carry the payload of a single 26-tone RU. Four SFUs are set in the simulation process, and each STA user carries one service, TS or NTS service; the proportion of TS users to the total number of users in each SFU varies randomly between 0.1 and 0.3; the comparison scheme adopted in the simulation is an access scheme based on trigger frame that does not distinguish between service types. The trigger frame of the comparison scheme contains all RU numbers and duration information used for random access. Since the user's cache status information is not obtained a priori through the BSRP-BSR mechanism, all RUs used for random access are set to the same size, all rooms are fully synchronized, and the same transmission duration is set.

[0239] Figure 7 (a) is a schematic diagram of the comparison results of the access delay of the present invention and the comparative scheme. As the number of STAs accessed in each SFU increases, the access delay of the comparative scheme also increases. This is because a large number of STAs competing for access to the wireless channel will cause collisions. The more users compete, the more intense the collisions will be. Transmission failures require waiting for the next round of competition, which affects the access delay of the overall user. The access delay of TS users in all schemes remains basically unchanged and is maintained at a low level below 5ms. Although the delay of NTS users increases with the increase in the number of users in the room, it is still lower than the comparative scheme. This is because the proposed priority-based access protocol increases the probability of successful reporting by TS users in the first phase, so that most TS users obtain dedicated resources in the second phase and do not need to compete with other users for access in the second phase. For NTS users, most TS users do not participate in the competition in the second phase, which also increases the probability of some NTS users successfully accessing the channel. The proposed scheme also adopts a collaborative resource allocation algorithm, which can dynamically allocate optical and wireless resources of different sizes to TS users according to their different traffic requirements, and allow rooms with fast transmission to flexibly perform multiple transmissions in a large transmission cycle without waiting for data from other rooms to be transmitted before transmitting again, thus reducing the waiting time due to synchronization and lowering the access delay. Figure 7(b) shows a schematic diagram of the comparison results of the access jitter of the present invention and the comparative solution. Jitter reflects the stability of access and can be calculated by the mean square error of access delay. The access jitter of the two service users of the proposed solution is lower than that of the comparative solution, which reflects the superiority of the proposed solution in access delay and jitter. Figure 7 (c) shows a schematic diagram of the comparison results of wireless resource utilization between the present invention and the comparative solution, which is calculated by dividing the bandwidth size of actual data transmission by the bandwidth size allocated to the user, wherein the unutilized portion of resources is a waste of resources due to the transmission of null values ​​due to the synchronous zero-padding requirement.

[0240] In the comparison scheme, since the service type is not distinguished and the traffic requirements of different services are not obtained a priori, the RU resource size and transmission time allocated to all users are fixed, which will result in a large degree of resource waste. This embodiment obtains the traffic requirements of most TS users in the first reporting stage, and dynamically allocates optical and wireless resources to TS users through a collaborative algorithm. There is no need for synchronous waiting between SFUs in different rooms, and asynchronous transmission also improves transmission efficiency and the utilization rate of resources allocated to TS users, reducing resource waste caused by zero padding. For NTS users, this embodiment fails to obtain their traffic bandwidth requirements, so it allocates fixed-size RUs and transmission times to them, so their resource utilization is similar to that of the comparison scheme. In summary, the present invention reduces the access delay and jitter of users of the two services, and significantly improves the resource utilization of TS users.

[0241] The resource allocation method in the centralized optical and wireless access network described in the present invention only obtains the cache status report of the delay-sensitive user who has successfully reported, and prioritizes the allocation of optical and wireless resources to the delay-sensitive user; when the delay-sensitive user is prioritized, the RU is initially allocated and redistributed for each user based on the bandwidth demand corresponding to the user, and the optical subcarrier is matched at the same time. By flexibly allocating RUs of different sizes and corresponding optical subcarriers to the delay-sensitive user, the different needs of the delay-sensitive user are accurately met, and the resource utilization rate is greatly improved. In the reporting stage, the present invention only allows delay-sensitive (TS) users to report cache status reports, and by limiting the competition of non-delay-sensitive (NTS) users, the probability of delay-sensitive users reporting successfully is greatly improved, so that the delay-sensitive user can be allocated optical and wireless resources preferentially in the future, effectively reducing the access delay of delay-sensitive users. The present invention adopts a strategy of synchronization within the room and asynchronism between rooms. During the transmission process in the room with a long transmission time, the room with a short transmission time is allowed to perform multiple rounds of transmission, reducing the waste of resources caused by synchronization alignment and zero padding, effectively reducing the access delay and jitter of delay-sensitive services, and significantly improving resource utilization.

[0242] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0243] 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.

[0244] 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.

[0245] 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 in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0246] Obviously, the above embodiments are merely examples for the purpose of 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 therefrom are still within the scope of protection of the present invention.

Claims

1. A method for allocating resources in a centralized optical and wireless access network, characterized in that: Applied in every room of the centralized optical and wireless access network, including: Based on the cache status report of the TS user who successfully reported, the bandwidth requirements of the TS users in the room are obtained, the total wireless transmission capacity and total optical transmission capacity required by the TS users in the room are calculated, and the wireless channel width of the room is obtained; Based on the wireless channel width and the ratio of the bandwidth requirement of each TS user to the total bandwidth requirement of the room, calculate the expected number of Schedule RUs for each TS user in the room; Based on the expected number of RUs of each TS user and the number of wireless subcarriers in each Schedule RU, obtain the initial number of RUs allocated to each TS user in the room; Based on the expected number of RUs and the initial number of RUs for each TS user, the scheduled RUs are reallocated to obtain the actual number of RUs for each TS user. Based on the number of wireless subcarriers in each Scheduled RU, obtain the wireless transmission rate corresponding to the TS user; Based on the actual number of RUs of each TS user and the number of wireless subcarriers in each scheduled RU, the number of optical subcarriers required to transmit the data of each TS user is calculated. Combined with the transmission rate of a single optical subcarrier, the optical transmission rate corresponding to each TS user is calculated. Based on the bandwidth requirement of each TS user and the wireless transmission rate and optical transmission rate corresponding to each TS user, the wireless transmission time and optical transmission time of each TS user are calculated; Resources are allocated based on the number of optical subcarriers, wireless transmission time, optical transmission time and preset Random RU transmission duration corresponding to each user.

2. The method for allocating resources in a centralized optical and wireless access network according to claim 1, characterized in that: Report the acquisition of the cache status report of the successful TS user, including: The MFU sends a cache status report polling frame to request cache status reports from all TS users; After receiving the buffer status report polling frame, each TS user obtains the RU information that can be used for random contention access, and uses the uplink OFDMA random access mechanism to randomly select an RU to upload the buffer status report: If the RU is selected by only one TS user, the cache status report of the TS user is successful; If the RU is selected by multiple TS users, the cache status reports of the multiple TS users that selected the RU fail to be reported.

3. The method for allocating resources in a centralized optical and wireless access network according to claim 1, characterized in that: Calculate the total wireless transmission capacity and total optical transmission capacity required by TS users in the room, and obtain the wireless channel width of the room, including: Based on the total number of supported users N in each room and the bandwidth requirements of TS users in each room, the total wireless transmission capacity required by TS users in each room is calculated, which is expressed as: Based on the total wireless transmission capacity required by TS users in all rooms, obtain the minimum available capacity to meet the needs of each room It is expressed as: Based on the minimum available capacity of all rooms As well as the total capacity of the OFDM passive optical network, calculate the total optical transmission capacity required by TS users in each room It is expressed as: Adjust the minimum available capacity to meet the needs of TS users in each room make Based on the minimum available capacity to meet the TS user needs in each room The preset relationship table with the wireless channel width obtains the wireless channel width B corresponding to the TS user in each room i ; in, represents the total wireless transmission capacity required by TS users in the i-th room, represents the bandwidth requirement of the jth TS STA in the i-th room, T i ′ represents the data transmission time of the i-th room in the previous round; M represents the total number of rooms supported by the centralized optical and wireless access network.

4. The method for allocating resources in a centralized optical and wireless access network according to claim 1, characterized in that: Based on the wireless channel width and the ratio of the bandwidth requirement of each TS user to the total bandwidth requirement of the room, the expected number of Schedule RUs for each TS user in the room is calculated, which is expressed as: in, represents the expected number of RUs of the jth TS STA in the i-th room, Indicates that the wireless channel width is B i The total number of RUs that can be supported when represents the bandwidth requirement of the jth TS STA in the ith room, and N represents the total number of users supported in each room.

5. The method for allocating resources in a centralized optical and wireless access network according to claim 1, characterized in that: Based on the expected number of RUs for each TS user and the number of wireless subcarriers in each Schedule RU, the initial number of Schedule RUs allocated to each TS user in the room is obtained, including: Based on the expected number of RUs for the jth TS user in the i-th room Calculate the RU granularity value l of the jth TS user in the i-th room i,j , expressed as: Calculate l of 2 i,j To obtain the initial RU number A allocated to the jth TS user in the i-th room i,j , expressed as:

6. The method for allocating resources in a centralized optical and wireless access network according to claim 1, characterized in that: Based on the expected number of RUs and the initial number of RUs for each TS user, the scheduled RUs are reallocated, including: Based on the wireless channel width and the initial number of RUs of each TS user, the total number of remaining RUs in the room is calculated, expressed as: Calculate the difference between the expected number of RUs and the initial number of RUs for each TS user, and obtain the number of RUs to be satisfied for each TS user, expressed as: In each room, the number of RUs to be satisfied of all TS users in the room is sorted in descending order, and based on the sorted TS users, the number of RUs to be satisfied of the TS users is calculated in order. i,j The total number of remaining RUs in the room For comparison: like Then, the Scheduled RU is allocated to the TS user, and the total number of remaining RUs in the room is updated; like The demand of the TS user cannot be met, and the number of RUs to be met for the next TS user is compared. i,j The total number of remaining RUs in the room The scheduled RUs are redistributed until the total number of remaining RUs in the room reaches 0.

7. The method for allocating resources in a centralized optical and wireless access network according to claim 1, characterized in that: Based on the number of wireless subcarriers in each Scheduled RU, the wireless transmission rate corresponding to the TS user is obtained, which is expressed as: in, represents the wireless transmission rate of the jth TS user in the i-th room, N SS Represents the number of spatial streams; A i,j represents the actual number of RUs allocated to the jth TS user in the i-th room, x represents the number of subcarriers contained in the RU, and A i,j *x represents the total number of subcarriers allocated to a TS user; N BPSCS,U represents the modulation order, R C Indicates the bit rate; T DFT Indicates the OFDM symbol length, T GI Indicates the symbol interval.

8. The method for allocating resources in a centralized optical and wireless access network according to claim 1, characterized in that: Based on the actual number of RUs of each TS user and the number of wireless subcarriers in each scheduled RU, the number of optical subcarriers required to transmit the data of each TS user is calculated. Combined with the transmission rate of a single optical subcarrier, the optical transmission rate corresponding to each TS user is calculated, including: Based on the actual number of RUs for each TS user and the number of radio subcarriers in each Scheduled RU, the number of optical subcarriers required to transmit the data in each TS user is calculated, expressed as: Based on the number of optical subcarriers required to transmit the data in each TS user and the transmission rate of a single optical subcarrier, the optical transmission rate corresponding to each TS user is calculated and expressed as: in, A represents the number of optical subcarriers required by the jth TS user in the i-th room. i,j represents the actual number of RUs allocated to the jth TS user in the i-th room, ρ represents the number of optical subcarriers required for the capacity provided by the wireless subcarrier of a scheduled RU, represents the optical transmission rate of the jth TS user in the ith room, and r represents the transmission rate of a single optical subcarrier.

9. The method for allocating resources in a centralized optical and wireless access network according to claim 1, characterized in that: Get the preset Random RU transmission duration, including: Get the number of RUs remaining in the channel after the scheduled RU allocation is completed, and use them as random RUs to allocate to TS users and NTS users who have not reported successfully. Calculate the number of optical subcarriers, wireless transmission rate, and optical transmission rate required by each user corresponding to the Random RU; Based on the bandwidth requirements of each user and the wireless transmission rate and optical transmission rate corresponding to each user, the wireless transmission time and optical transmission time of each user are calculated, and combined with the transmission time of the frame in the network, the Random RU transmission duration is obtained.

10. The method for allocating resources in a centralized optical and wireless access network according to claim 9, characterized in that: Calculate the number of optical subcarriers, wireless transmission rate, and optical transmission rate required by each user corresponding to the Random RU, including: Based on the wireless channel width corresponding to the i-th room and the maximum bandwidth of the wireless channel, calculate the number of RandomRU in the i-th room It is expressed as: Based on the total number of Random RUs in all rooms The total number of optical subcarriers used for scheduling access is calculated by the number of optical subcarriers required for each RU capacity, ρ It is expressed as: Based on the total number of Schedule RUs in all rooms The total number of optical subcarriers used for random access is calculated by comparing the number of optical subcarriers required for each RU capacity ρ It is expressed as: Compare whether the number of remaining photocarriers in the OFDM passive optical network, except for the photocarriers used for scheduling access, meets the total number of photocarriers used for random access: like The remaining optical subcarriers are then allocated to users as needed; like The remaining optical subcarriers are allocated to users in proportion; when the proportion is allocated, the number of optical subcarriers allocated to each user is Based on the number of wireless subcarriers in each Schedule RU, the wireless transmission rate corresponding to the user is obtained; based on the actual number of RUs of each user and the number of wireless subcarriers in each Schedule RU, the number of optical subcarriers required to transmit the data of each user is calculated, and combined with the transmission rate of a single optical subcarrier, the optical transmission rate corresponding to the user is calculated; in, Indicates the total number of RUs that can be supported when the wireless channel width is B; Indicates that the wireless channel width is B i When , the total number of RUs that can be supported; M represents the total number of rooms supported in the centralized optical and wireless access network, and N represents the total number of users supported in each room; A i,j represents the actual number of RUs allocated to the jth TS user in the i-th room, represents the number of Random RUs used for random access in the i-th room; U represents the total number of subcarriers in the orthogonal frequency division multiplexing passive optical network.

11. The method for allocating resources in a centralized optical and wireless access network according to claim 9, characterized in that: Based on the bandwidth requirements of each user and the wireless transmission rate and optical transmission rate corresponding to each user, the wireless transmission time and optical transmission time of each user are calculated, and combined with the transmission time of the frame in the network, the Random RU transmission duration is obtained, including: Based on the bandwidth requirement of the jth TS user in the i-th room The corresponding wireless transmission rate Calculate the wireless transmission time of the jth TS user in the i-th room It is expressed as: Bandwidth requirement of the jth TS user in each i-th room The corresponding optical transmission rate Calculate the optical transmission time of the jth TS user in the i-th room It is expressed as: Based on the maximum wireless transmission time T of all TS users in the i-th room i W Maximum light transmission time and cache status report transmission time T BSR , trigger frame transmission time T TF , processing time T Process , Time required to confirm the frame T ACK and the short interframe spacing time SIFS, calculate the maximum transmission duration T i , and use the maximum transmission time as the Random RU transmission duration, expressed as: in, 12. The method for allocating resources in a centralized optical and wireless access network according to claim 11, characterized in that: After obtaining the number of optical subcarriers, wireless transmission time, optical transmission time and Random RU transmission duration corresponding to each user, it also includes: Enables synchronous transmission between different users in the same room; Between different rooms, during the transmission process of users with long transmission time, users with short transmission time are allowed to perform multiple rounds of transmission; The transmission time T required for a new round of transmission by a user with short transmission time i ″, expressed as: like A new round of transmission cannot be performed; like A new round of transmission is then performed and the maximum remaining time is updated in, Represents the maximum transmission time of a user, expressed as T i Indicates the maximum transfer duration.

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