CN116017748A - Flexible high-speed rail wireless access network networking method - Google Patents
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Abstract
The invention discloses a flexible high-speed rail wireless access network networking method, which deploys corresponding networking schemes according to different high-speed rail line scenes; accessing a network through a related networking scheme according to a line scene of a high-speed rail, and determining the scheduling priority of each communication service according to the high-speed rail service type and the corresponding QoS priority; according to the dispatching priority of each communication service, carrying out self-adaptive wireless access network rearrangement on each communication service; and scheduling the resources of each communication service by combining the scheduling priority of each communication service through a scheduling algorithm. The method can realize the differentiated wireless network facility deployment of different high-speed rail service areas so as to meet the service quality such as the access performance, the mobile performance, the channel maintenance performance and the like of the railway 5G private network and ensure the low-delay and high-speed communication requirements of high-speed rail users.
Description
Technical Field
The invention relates to the technical field of networks, in particular to a flexible high-speed rail wireless access network networking method.
Background
Along with the rapid development of economy and continuous progress of science and technology, the high-speed railways in China enter a new development stage, meanwhile, the business requirements of communication among the high-speed rail transit vehicles are continuously expanded, and various new business requirements such as mobile video detection control, remote real-time detection of train condition information, optimal control and automatic driving, intelligent trains, railway Internet of things, passenger services and the like are continuously emerging and increasingly urgent. The method has more stringent requirements on high reliability, low time delay, large bandwidth, mass machine communication and the like of the high-speed railway private network communication.
However, the GSM-R adopted by the railway mobile communication private network at present cannot meet the requirements of the service. The GSM-R, which is a second generation mobile communication technology, belongs to a narrow-band communication system, and mainly carries voice service and a small amount of data service, and has a low data rate, so that it is difficult to further support the increasing new service requirements, especially the high-reliability low-delay service requirements. And the fifth generation mobile communication technology 5G NR supports three application scenes by introducing large-scale MIMO (Massive MIMO), millimeter wave and other technologies: the method is high in reliability and low in time delay (uRLLC), mass connection (mMTC) and enhanced in mobile bandwidth (eMBB), and is more suitable for the requirements of the communication of the existing high-speed rail private network. Therefore, the 5G private network (5G-R) is further researched based on the 5G NR communication technology, so that the method is favorable for establishing full-scene, full-service and full-link oriented between the train and the ground, and high-speed mobile, high-speed, high-reliability, high-real-time and high-safety high-speed railway communication links are supported.
The effective application of the 5G NR communication technology in the high-speed railway can be realized through the rearrangement of the self-adaptive network structure taking the network slicing technology as a carrier, and the technology can pertinently perform the rearrangement of the self-adaptive network structure and the resource scheduling of the RB (resource block) according to different services encountered in the running process of the high-speed railway so as to realize the network access of different services with higher reliability and low time delay.
For the resource scheduling schemes in the high-speed railway scene, in the scene that the common users and the high-speed train users are served by the same base station in the cellular network (namely, the public network scene), there are a plurality of classical scheduling schemes, such as a polling method, a maximum carrier-to-interference ratio algorithm, a proportional fairness algorithm and the like, but considering that the resource scheduling schemes cannot be directly applied to the high-speed railway 5G private network, the research on the resource scheduling schemes suitable for the high-speed railway 5G private network has practical research value.
Disclosure of Invention
The invention aims to provide a flexible high-speed railway wireless access network networking method which can realize the differentiated wireless network facility deployment of different high-speed railway service areas so as to meet the service quality such as the access performance, the mobile performance, the channel maintenance performance and the like of a railway 5G private network and ensure the low-delay and high-speed communication requirements of high-speed railway users.
The invention aims at realizing the following technical scheme:
a flexible high-speed rail wireless access network networking method, comprising:
corresponding networking schemes are deployed according to different line scenes of the high-speed rail;
accessing a network through a related networking scheme according to a line scene of a high-speed rail, and determining the scheduling priority of each communication service according to the high-speed rail service type and the corresponding QoS priority;
according to the dispatching priority of each communication service, carrying out self-adaptive wireless access network rearrangement on each communication service; and scheduling the resources of each communication service by combining the scheduling priority of each communication service through a scheduling algorithm.
The technical scheme provided by the invention can be used for distributing proper resources to users with the aim of guaranteeing the QoS (Quality of Service ) of the service under the given frequency resources, and maximizing the utilization rate of the wireless resources on the premise of meeting the quality of service of different high-speed rail services.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a flowchart of a method for networking a flexible high-speed rail wireless access network according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a high-speed rail-based station spacing arrangement according to an embodiment of the present invention;
fig. 3 is a schematic diagram of a common-cell chain coverage scheme of a baseband processing unit, a remote radio unit and a power divider provided in an embodiment of the present invention;
fig. 4 is a schematic diagram of a network structure of a high-speed rail private network based on a service provided in an embodiment of the present invention;
fig. 5 is a flowchart of an improved RAD resource scheduling algorithm according to an embodiment of the present invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to fall within the scope of the invention.
The terms that may be used herein will first be described as follows:
the term "and/or" is intended to mean that either or both may be implemented, e.g., X and/or Y are intended to include both the cases of "X" or "Y" and the cases of "X and Y".
The terms "comprises," "comprising," "includes," "including," "has," "having" or other similar referents are to be construed to cover a non-exclusive inclusion. For example: including a particular feature (e.g., a starting material, component, ingredient, carrier, formulation, material, dimension, part, means, mechanism, apparatus, step, procedure, method, reaction condition, processing condition, parameter, algorithm, signal, data, product or article of manufacture, etc.), should be construed as including not only a particular feature but also other features known in the art that are not explicitly recited.
The term "consisting of … …" is meant to exclude any technical feature element not explicitly listed. If such term is used in a claim, the term will cause the claim to be closed, such that it does not include technical features other than those specifically listed, except for conventional impurities associated therewith. If the term is intended to appear in only a clause of a claim, it is intended to limit only the elements explicitly recited in that clause, and the elements recited in other clauses are not excluded from the overall claim.
Unless specifically stated or limited otherwise, the terms "mounted," "connected," "secured," and the like should be construed broadly to include, for example: the connecting device can be fixedly connected, detachably connected or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the terms herein above will be understood by those of ordinary skill in the art as the case may be.
The research on resource scheduling in the high-speed rail scene is focused on allocating proper resources to users with the aim of guaranteeing QoS (quality of service) of service under the given frequency resource, and maximizing the utilization rate of wireless resources on the premise of meeting the quality of service of different high-speed rail services. The service in the high-speed rail communication has higher requirements on transmission delay and reliability, so that the service characteristics are considered, and QoS requirement indexes of each service of the high-speed rail are clearly known so as to reasonably allocate RB resources. Therefore, the embodiment of the invention provides a flexible high-speed railway wireless access network networking method, which firstly realizes the differentiated wireless network facility deployment of different high-speed railway service areas, and on the basis, self-adaptive network structure rearrangement and resource scheduling are purposefully carried out according to the priority of communication service so as to meet the service quality such as railway 5G private network access performance, mobility performance, channel maintenance performance and the like, and ensure the low-delay and high-speed communication requirements of high-speed railway users.
The following describes a flexible high-speed rail wireless access network networking method provided by the invention in detail. What is not described in detail in the embodiments of the present invention belongs to the prior art known to those skilled in the art. The specific conditions are not noted in the examples of the present invention and are carried out according to the conditions conventional in the art or suggested by the manufacturer. The equipment used in the examples of the present invention was not manufacturer-identified and was a conventional product commercially available.
As shown in fig. 1, a flowchart of a method for networking a flexible high-speed rail wireless access network according to an embodiment of the present invention mainly includes the following steps:
step 1, deploying corresponding networking schemes according to different line scenes of the high-speed rail.
In the embodiment of the invention, main scenes of the deployment of the high-speed railway private network, including a railway main line scene and a tunnel scene, are determined according to the main running line of the high-speed railway, and different networking deployment schemes are provided.
1) Aiming at a high-speed rail positive line scene, a networking scheme of a chain type cell continuous coverage and a common cell mode based on RRU (Remote Radio Unit ) is adopted.
When the continuous coverage of the chain type cell is adopted, the station spacing of the base station and the vertical distance of the base station are set.
When the base station spacing is set, a base station spacing calculation formula is adopted as follows:
base station inter-station distance = 2 (radius of coverage 2 -station gauge 2 ) 1/2 -overlap distance
In the above, the gauge of the station is the distance between two rails of the railway track; the coverage radius is calculated using the maximum path loss allowed by the link, specifically: the maximum allowed path loss calculation formula is: maximum allowed path loss=equivalent transmitting power+antenna gain of transmitting terminal-feeder line and joint loss of transmitting terminal-human body loss-penetration loss-sensitivity of receiving terminal+antenna gain of receiving terminal-feeder line and joint loss of receiving terminal-interference margin-fading margin, and the value of the relevant parameter when calculating maximum allowed path loss is determined according to the actual condition of planning area). The maximum coverage distance, i.e. the coverage radius, of the base station can be calculated by substituting the maximum allowed path loss into the Okumura-Hata propagation model.
The calculation formula of the overlapping distance is: overlap distance= (switching delay corresponding distance+switching measurement corresponding distance+time corresponding distance for performing switching) ×2. As shown in fig. 2, the rectangular box area filled with vertical lines is the switching delay corresponding distance, which is the distance required for the signal to meet the switching level hysteresis; the rectangular frame area filled by the transverse line is the corresponding distance of switching measurement, which is the reporting period of terminal measurement plus the delay of switching time; the rectangular frame area filled with oblique lines is the corresponding distance of the time for executing the switching, and the time for executing the switching comprises the execution time of the signaling plane and the data plane. Because of the bi-directional handover relationship between cells, the overlapping coverage distance setting should be 2 times the distance required to complete the handover.
When the vertical distance of the base station is set, as the penetration loss of the coverage area edge signal entering the carriage is larger when the vertical position of the base station is closer to the railway, the calculation formula of the vertical distance f of the base station is adopted as follows:
wherein S is the distance between base stations, and θ is the glancing angle.
The cell sharing mode based on the remote radio units adopts a BBU (Building Baseband Unit, baseband processing unit), the remote radio units and a power divider, as shown in fig. 3, namely, each communication tower mast is provided with a two-channel remote radio unit, is connected with two dual-polarized directional antennas through the power divider and covers railways on two sides of the communication tower mast, each communication tower mast is a substation, and the substation is connected to the baseband processing unit which is arranged in a centralized manner through an optical cable.
2) Aiming at the high-speed rail tunnel, wireless coverage is carried out by adopting a distributed base station, a leaky coaxial cable and a directional antenna, and a related networking scheme is provided. Namely, BBU stations outside railway infrared are used as information sources, and RRUs and POIs (Point of Interface, multi-system combining platforms) are arranged on a tunnel entrance highway field level or in a tunnel hole. The RRU feeds multi-system signals into the POI, the POI covers the tunnel through the leaky coaxial cable after the signals are combined, and the RRU directly covers the tunnel opening through the directional antenna at the tunnel opening. Specific:
and wireless signal coverage is carried out in the tunnel by adopting a distributed base station and leaky coaxial cable mode. Since the 5/4 'leaky cable theoretical cutoff frequency is about 3.7GHz, a 5/4' leaky cable is used to carry the 5G signal. The laying height of the leaky cable is set to be about 2m from the lower edge of the window of the high-speed train to the height of the rail surface, and the upper edge of the window is about 2.7m from the rail surface. In order to ensure the incident angle of signals, the height of the window of the high-speed railway and the height of the illumination cable are combined, the hanging heights of 2 5/4' leaky cables are respectively 2.1m and 2.55m from the rail surface, the leaky cable holes point to the window, and the leaky cables of the public network and the grotto where the equipment is located are laid on the same side.
The cable-leaking covering distance is as follows: the wireless network coverage distance L (unit: m) when both ends of the leaky cable have the information source access can be calculated by the following formula:
wherein P is t Output power (dBm) of leaky cable, N 1 For jumper splice loss (dB), N 2 Is the combiner loss (dB), L 0 To the required in-car field strength (dBm), L 1 Is the air coupling loss (dB) of the leaky cable, L 2 For the switching interval (M), M 1 For system margin (dB), M 2 Is a width factor (dB), M 3 M is the dielectric loss (dB) of the car body 4 Is human body loss (dB).
The tunnel portal adopts a distributed base station and directional antenna mode to carry out signal coverage. The site is a plateau station mode. The field level station is a simple communication base station which is built at the tunnel portal, and is generally built by adopting a holding pole, but no communication tower is built. The station equipment comprises POI, RRU, vertical light cross boxes, vertical distribution boxes, directional antennas and the like, and is provided with 2 9m steel rods, wherein the POI, RRU and directional antennas are all hung on the steel rods. The POI provides signals for leaky cables in the tunnel, and the directional antenna is directly connected with the RRU to provide signals.
And 2, accessing a network through a related networking scheme according to a line scene of the high-speed rail, and determining the scheduling priority of each communication service according to the high-speed rail service type and the corresponding QoS priority.
According to different tasks of the high-speed rail in different road sections, main communication services in the running process of the high-speed rail are mainly classified into 5 types, namely a train running control service (CBTC service), an emergency text service, a passenger information system video service (PIS service), a train state monitoring service and a video monitoring system service (IMS service). QoS requirements for different services are different, and the resource allocation manners are also different. Wherein the QoS requirements of different services determine the scheduling priority of their services and the subsequent resource allocation manner. The preferred embodiment of this step is as follows:
1) And analyzing the QoS requirements of the high-speed rail service.
According to 3GPPTS23.203, the QoS requirement analysis of the high-speed rail main 5-class traffic is presented as table 1.
Table 1: qoS index feature of high-speed rail main communication service
| Service type | QCI | Resource type | Priority level | Bao Yanshi | Packet loss rate | Transmission rate |
| CBTC service | 1 | |
2 | 150ms | 10 -2 | 100kbps |
| Emergency |
2 | GBR | 4 | 150ms | 10 -3 | 100kbps |
| PIS service | 6 | Non-GBR | 6 | 300ms | 10 -6 | 2-6Mbps |
| Train |
2 | GBR | 4 | 150ms | 10 -3 | 100kbps |
| IMS services | 6 | Non-GBR | 6 | 300ms | 10 -6 | 1-2Mbps |
Wherein QCI (QoS Class Identifier) is a QoS class indication, and one QCI value corresponds to a corresponding QoS attribute, and includes indexes such as a resource type (GBR or non-GBR), a priority (priority, the smaller the value is, the higher the priority), bao Yanshi (Packet Delay Budget), and a Packet Loss Rate (Packet Loss Rate), and 9 different QCI values are specified in the protocol. Table 1 lists QCI indicators for the most advanced 5-class traffic, with the addition of non-QCI indicator types and transmission rate indicators.
2) After the QoS index of the traffic is obtained, the scheduling priority of the communication traffic may be measured.
In the embodiment of the invention, an MSPF (Multi-service Proportional Fairness, multi-service proportional Fair scheduling) algorithm is adopted, so that a measurement based on scheduling priority can be carried out on different communication services.
Firstly, calculating the rate requirement weight of the communication service and the QoS requirement weight of the communication service, wherein the calculation formula is as follows:
wherein r is k，j The minimum required rate for traffic j representing high-speed railway k (the lower limit of the transmission rate of table 1 can be used as a standard),
the average rate of the high-speed railway k-representing service j from the beginning of the high-speed railway dispatch to the time t is calculated by the following method
R k，i，j (T) is the actual obtained rate on the subcarrier at time T for traffic j of high-speed rail k, T w For a defined size of the time window; w (W) r (t) represents the rate requirement weight of the high-speed railway k service j at the time t, and is a weight term defined for the service with the rate requirement (GBR service); d (D) k，j (T) current buffer queue delay, T, for high-speed rail k traffic j k . j (t) traffic representing high-iron kj (packet delay of table 1 can be used as standard, e.g. 150ms or 300 ms), lambda k，j QoS priority parameter of high-speed railway business i (priority index of table 1 can be used as standard), mu represents speed factor control parameter (which can be adjusted according to actual condition, value range is 0-1, and no requirement is made for speed control when value is 0); alpha and beta are control parameters of QoS requirement weight, and alpha controls sensitivity of packet delay requirement, and the value is 0<Alpha is less than or equal to 1, the value of alpha is not 0, the judgment of the priority of the user and the service is required to always consider the packet delay, and beta controls the relative priority of the service, and the value of alpha is a positive integer including 0; w (W) n And (t) represents the QoS requirement weight of the high-speed rail k service j at the moment t, and the QoS requirements of different services are defined, wherein the QoS requirements comprise the packet delay requirement of the service and the QoS relative priority requirement of the service.
The scheduling priority of each communication service is calculated, and the calculation formula is as follows:
wherein m is k，i，j (t) represents the scheduling priority of traffic j of high-speed rail k on subcarrier i at time t.
By the method, the scheduling priority of each service at each moment in the running process of each high-speed rail can be calculated, and after the scheduling priority is obtained, the subsequent resource allocation process can be padded.
After the scheduling priority of each communication service is obtained in the aforementioned step 2, adaptive wireless access network rearrangement and resource scheduling can be performed.
1) Adaptively radio access network reordering.
In the embodiment of the invention, the rearrangement of the network structure based on the service is the network slice switching process which is responsible for different services, and the network structures of different slices are different. The aforementioned 5-class communication traffic is classified into the two classes of ul lc (Ultra Reliable Low Latency Communications, high reliability low latency) traffic and eMBB (Enhanced Mobile Broadband, enhanced mobile bandwidth) traffic according to QoS requirements of different traffic. The eMBB service needs high throughput rate scheduling, the ul lc service needs ultra-low time delay and ultra-high reliability guarantee, and according to 3gpp ts23.502, train operation control service (CBTC service), emergency text service, and train status monitoring service are assigned to the ul lc service, and passenger information system video service (PIS service) and video monitoring system service (IMS service) are assigned to the eMBB service.
Fig. 4 is a schematic diagram of a service-based high-speed rail private network structure, and fig. 4 shows the structures of the ul lc slice and the eMBB slice. The uRLLC service and the eMBB service are respectively responsible for a uRLLC slice and an eMBB slice, and the bottom physical resources used by the two slices are the same and mainly comprise the resources of calculation, storage and network transmission of the whole high-speed railway private network; the network structure of the two slices is different, and the specific differences are as follows:
aiming at uRLLC slicing, a method of combining a macro base station and a micro base station is adopted, wherein the macro base station is responsible for communication (control plane) related to high-speed railway running control, processes all configuration of a high-speed railway train based on RRC (Radio Resource Control ) layers, and is responsible for communication (user plane) related to high-speed railway user service, deployed in the coverage area of the macro base station and used for providing user scheduling service and user communication service for the high-speed railway train; the combination of the macro base station and the micro base station can effectively eliminate signal blind areas, improve communication quality, improve transmission reliability, meanwhile, clear signal processing division can improve information processing efficiency and reduce transmission delay.
Aiming at eMBB slicing, a network base station is deconstructed into a composition mode of a base band processing unit pool and a radio remote unit, the base band processing unit pool and the radio remote unit are connected through a high-capacity optical fiber, the base band processing unit pool is composed of a plurality of processors, a base band processing function is executed, the radio remote unit is located at an antenna of a far base station, and the antenna is controlled by a virtual base station in the base band processing unit pool to provide wireless signal coverage for a high-speed railway train. The deployment mode can realize networking with the high-speed railway users as the center, and improves the transmission rate and the network capacity of the users by utilizing centralized signal processing and resource scheduling.
2) And (5) scheduling resources.
After the scheduling priority of different communication services is obtained, the resource scheduling can be realized by carrying out RB (resource block) allocation on the different communication services based on the scheduling priority. The present invention uses an improved directed acyclic graph Routing (RAD) resource scheduling algorithm, a specific flow diagram is shown in fig. 5.
Some descriptions are made before resource scheduling: 1) Determining the resource types of each communication service, wherein the resource types comprise GBR and Non-GBR, different communication services encountered at the same time in the high-speed rail are divided into two types according to the resource types, one type is GBR service, and the other type is Non-GBR service; wherein GBR (Guaranteed Bit Rate bit rate) represents a guaranteed bit rate and Non-GBR represents a Non-guaranteed bit rate; before each scheduling period, checking whether GBR service exists in the service buffer queue, if so, executing resource scheduling on the corresponding GBR service according to the corresponding scheduling priority, and then executing resource scheduling of Non-GBR service; and if not, directly executing the resource scheduling of the Non-GBR service. Fig. 5 shows a flow of scheduling resources of GBR traffic first and then Non-GBR traffic when GBR traffic is present, and when GBR traffic is not present, scheduling resources of Non-GBR traffic directly using the flow shown in the lower right corner of fig. 5.
2) Setting a scheduling period to 1 TTI (1 ms), and simultaneously carrying out wireless resource allocation by taking a resource block pair (Resource Block Pairs, RBP) formed by two resource blocks as a unit, wherein the subcarrier frequencies of the two resource blocks in the resource block pair are limited to be the same; 3) The same resource block pair is allocated to the same communication service of the same high-speed rail only, namely if one resource block in the resource block pair has partial vacant resource blocks, the partial vacant resource blocks can not participate in allocation, and if only 1 resource block in one resource block pair is occupied by data of a certain service of the high-speed rail, the rest other resource block pair can be allocated.
The following description will be made with respect to the resource allocation of GBR service and the resource allocation of Non-GBR service.
A) Resource allocation for GBR traffic.
A1 All GBR services needing to be subjected to resource scheduling are determined to form a GBR group, and the GBR services in the GBR group are ordered according to the descending order of the scheduling priority values of the GBR services (the ordered result is the sequence of resource scheduling). The smaller the value, the higher the priority, the higher the ranking.
A2 Respectively calculating the number of pairs of resource blocks required by each GBR service at t time in the scheduling period, and counting the total number N of the pairs of resource blocks required by the GBR group GBR 。
The formula of the number of resource block pairs N [ N ] [ t ] required by each GBR service N at the time t is as follows:
wherein, WCQI is coding efficiency; cqimodulion represents CQI (Channel Quality lndicator, channel quality indication) modulation order; RENum is the number of REs (Resource Element) in one Resource block (typically 12 in size); RI is rank indication information;
the bit number still to be transmitted at time t in the scheduling period is represented by the following formula:
wherein CurrentTTI represents the current TTI number (i.e. the number of the current period); serviceBeginTTI represents service initiation time; the PHYCorrectReieivebits represents the number of correctly transmitted MAC layer bits; GBR is a transmission rate that GBR traffic needs to satisfy, and the transmission rate index of table 1 may be used as a standard.
Adding the number of the resource block pairs required in the GBR group to obtain the total number N of the resource block pairs required by the GBR service GBR Expressed as:
where GBRList denotes the GBR traffic list in the GBR group.
A3 According to N GBR Whether or not it is greater than a threshold value N m ＝[μ m ·N RBP ]The resource allocation of GBR traffic is divided into two cases. N (N) RBP Mu, the number of resource block pairs (RB pairs) in one scheduling period m Is a custom scale value.
If N GBR ≥N m Indicating that the GBR service expects that the amount of radio resources required in one scheduling period is large, and the resource block pairs cannot be allocated to all GBR services, allocating N according to the ordered result m And the GBR services of the unassigned resource block pairs are subjected to resource allocation in the next scheduling period, namely the GBR services are put into the next scheduling period and are subjected to resource allocation again together with the services in the next scheduling period.
If N GBR <N m Sequentially distributing needed resource block pairs for all GBR services of the GBR group according to the sequencing result; in this case, it is explained that the GBR traffic expects not much radio resource to be required in one scheduling period, and there are remaining resource block pairs that can satisfy the requirements of all GBR traffic, and the remaining RBPs will be allocated to Non-GBR group traffic for demand allocation.
B) Resource allocation for Non-GBR traffic.
Counting available wireless resources, determining available resource block pairs, and then utilizing the available resource block pairs to carry out resource scheduling of Non-GBR service; the remaining resource block pairs after GBR service resource allocation include the following three cases:
case one: and if the resource block pair is not allocated and occupied at all, recalculating the scheduling priority of each Non-GBR service, and allocating the whole resource block pair to a certain Non-GBR service.
And a second case: and if only 1 resource block is allocated and occupied by two resource blocks in the resource block pair, recombining the unallocated resource blocks in different resource block pairs into a resource block pair to participate in the allocation of Non-GBR service.
Case three: both resource blocks in the resource block pair are allocated and occupied, and although one of the resource blocks still has partial spare resources unused, the same resource block can only be allocated to the same service of the same high-speed rail, so that the allocation is not performed any more.
I.e. the resource block pairs in the aforementioned case one and case two belong to the available resource block pairs.
The resource scheduling mode of Non-GBR service is as follows:
b1 Determining all Non-GBR services needing to be subjected to resource scheduling to form a Non-GBR group, recalculating the scheduling priority of each Non-GBR service, and sequencing the Non-GBR services in the Non-GBR group according to the scheduling priority of each Non-GBR service from small to large, wherein the sequencing result is the sequence of resource scheduling.
The high-speed railway communication service belonging to Non-GBR service comprises PIS service and IMS service, and because both are Non-real-time service, the formula W r The μ value in (t) is 0, the rate requirement weight is a fixed value 1, and the scheduling priority formula of updating Non-GBR service is:
and (3) recalculating the scheduling priority of Non-GBR service (i.e. PIS service and IMS service) on the subcarrier i at the time t in the scheduling period by the aid of the method.
B2 The number of pairs of resource blocks required by each Non-GBR service in the current scheduling period is calculated respectively.
The number of the allocated resource block pairs of the Non-GBR service is related to the buffer capacity of the service accumulated in the current scheduling period, and is in direct proportion to the proportion of the buffer capacity occupied by the service, the more the buffer capacity is, the more the allocated resource block pairs are, and the calculation formula is as follows:
wherein, currentbuffer k，j Sigma currentbuffer, which is the accumulated buffer amount of Non-GBR traffic j of high-speed rail k in the current scheduling period k The cumulative buffer size of the total Non-GBR traffic for the high-speed rail k in the current scheduling period.
B3 After the scheduling priority of each Non-GBR service and the number of RBPs to be allocated are obtained, the Non-GBR service can be allocated according to three conditions of the resource block at the moment: for the resource block pair of the first case, two resource blocks of the resource block pair are allocated to Non-GBR service with higher priority (namely, are sequentially allocated according to the priority order); for the second case, the resource block pair is formed by recombining the unassigned resource blocks in different resource block pairs, and the unassigned resource blocks are also assigned in sequence according to the priority order, namely assigned to Non-GBR service with higher priority; the RBP of the third case does not participate in calculation; non-GBR traffic not allocated to the resource block pair is delayed until the next scheduling period, and the scheduling of the resources of the Non-GBR traffic in the next scheduling period is participated.
From the description of the above embodiments, it will be apparent to those skilled in the art that the above embodiments may be implemented in software, or may be implemented by means of software plus a necessary general hardware platform. With such understanding, the technical solutions of the foregoing embodiments may be embodied in a software product, where the software product may be stored in a nonvolatile storage medium (may be a CD-ROM, a U-disk, a mobile hard disk, etc.), and include several instructions for causing a computer device (may be a personal computer, a server, or a network device, etc.) to perform the methods of the embodiments of the present invention.
The foregoing is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions easily contemplated by those skilled in the art within the scope of the present invention should be included in the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.
Claims (10)
1. A flexible high-speed rail wireless access network networking method, comprising:
corresponding networking schemes are deployed according to different line scenes of the high-speed rail;
accessing a network through a related networking scheme according to a line scene of a high-speed rail, and determining the scheduling priority of each communication service according to the high-speed rail service type and the corresponding QoS priority;
according to the dispatching priority of each communication service, carrying out self-adaptive wireless access network rearrangement on each communication service; and scheduling the resources of each communication service by combining the scheduling priority of each communication service through a scheduling algorithm.
2. The flexible high-speed rail wireless access network networking method according to claim 1, wherein the deploying the corresponding networking scheme according to different high-speed rail line scenes comprises:
aiming at a high-speed rail positive line scene, adopting a networking scheme of a chain type cell continuous coverage and a cell sharing mode based on a remote radio unit;
aiming at a high-speed railway tunnel, wireless coverage is carried out by adopting a distributed base station, a leaky coaxial cable and a directional antenna, a related networking scheme is provided, wherein wireless signal coverage is carried out in the tunnel by adopting the distributed base station and the leaky coaxial cable, and signal coverage is carried out at a tunnel opening by adopting the distributed base station and the directional antenna.
3. A flexible high-speed rail wireless access network networking method as defined in claim 2, wherein,
when adopting the continuous coverage of the chain type cell, setting the station spacing of the base station and the vertical distance of the base station;
when the base station spacing is set, a base station spacing calculation formula is adopted as follows:
base station inter-station distance = 2 (radius of coverage 2 -station gauge 2 ) 1/2 -overlap distance
In the above, the coverage radius is calculated by using the maximum path loss allowed by the link, and the station gauge is the distance between two rails of the railway track; the calculation formula of the overlapping distance is: overlap distance= (switching delay corresponding distance+switching measurement corresponding distance+time corresponding distance for performing switching) ×2;
when the vertical distance of the base station is set, a calculation formula of the vertical distance d of the base station is adopted as follows:
wherein S is the distance between base stations, and θ is the glancing angle.
4. The method for networking a flexible high-speed rail wireless access network according to claim 2, wherein the common cell mode based on the remote radio units is a common cell mode of adopting a baseband processing unit, the remote radio units and a power divider, namely, each communication tower mast is provided with a dual-channel remote radio unit, is connected with two dual-polarized directional antennas through the power divider, covers railways on two sides of the communication tower mast, each communication tower mast is a substation, and the substation is connected to the baseband processing unit which is arranged in a centralized manner through an optical cable.
5. The method for flexible high-speed rail wireless access network networking according to claim 1, wherein determining the scheduling priority of each communication service according to the high-speed rail service type and the QoS class comprises:
calculating the rate requirement weight of the communication service and the QoS requirement weight of the communication service, wherein the calculation formula is as follows:
wherein r is k,j Representing the minimum required rate for high-k traffic j,
representing the average rate, W, of high-speed rail k traffic j from the start of high-speed rail schedule to time t r (t) represents the rate requirement weight of the high-speed rail k service j at the time t; d (D) k,j (T) current buffer queue delay, T, for high-speed rail k traffic j k,j (t) tolerance threshold, lambda, for packet delay of high-speed rail k traffic j k,j QoS priority parameter of high-speed railway k service j, mu represents rate factor control parameter, alpha and beta are control parameters of QoS requirement weight, W n (t) represents the QoS requirement weight of the high-speed rail k service j at the time t;
adopting a multi-service proportional fair scheduling algorithm to calculate the scheduling priority of each communication service, wherein the calculation formula is as follows:
wherein m is k,i,j (t) represents the scheduling priority of traffic j of high-speed rail k on subcarrier i at time t.
6. The method for forming a flexible high-speed rail wireless access network according to claim 1, wherein said adaptively reordering each communication service according to a scheduling priority of each communication service comprises:
communication services are divided into a uRLLC service and an eMBB service, and are respectively controlled and managed by a uRLLC slice and an eMBB slice; wherein uRLLC represents high reliability low latency, eMBB represents enhanced mobile bandwidth;
aiming at uRLLC slicing, a method of combining a macro base station and a micro base station is adopted, the macro base station is responsible for communication related to high-speed railway running control, all configurations of a high-speed railway train based on a radio resource control layer are processed, and the micro base station is responsible for communication related to high-speed railway user service and is deployed in a coverage area of the macro base station and used for providing user scheduling service and user communication service for the high-speed railway train;
aiming at eMBB slicing, a network base station is deconstructed into a composition mode of a base band processing unit pool and a radio remote unit, the base band processing unit pool and the radio remote unit are connected through a high-capacity optical fiber, the base band processing unit pool is composed of a plurality of processors, a base band processing function is executed, the radio remote unit is located at an antenna of a far base station, and the antenna is controlled by a virtual base station in the base band processing unit pool to provide wireless signal coverage for a high-speed railway train.
7. The method for networking a flexible high-speed rail wireless access network according to claim 1, wherein the scheduling of resources for each communication service by a scheduling algorithm in combination with a scheduling priority of each communication service comprises:
determining the resource types of each communication service, wherein the resource types comprise GBR and Non-GBR, different communication services encountered at the same time in the high-speed rail are divided into two types according to the resource types, one type is GBR service, and the other type is Non-GBR service; wherein GBR represents guaranteed bit rate and Non-GBR represents Non-guaranteed bit rate; before each scheduling period, checking whether GBR service exists in the service buffer queue, if so, performing resource allocation on the corresponding GBR service according to the corresponding scheduling priority, and then executing resource scheduling of Non-GBR service; if not, directly executing the resource scheduling of the Non-GBR service;
each scheduling period is characterized in that resource allocation is carried out by taking a resource block pair consisting of two resource blocks as a unit, and the subcarrier frequencies of the two resource blocks in the resource block pair are the same; the resource block pairs are allocated, and the same resource block is only allocated to the same communication service of the same high-speed rail.
8. The method for flexible high-speed rail wireless access network networking according to claim 7, wherein the scheduling of resources for the GBR traffic according to the corresponding scheduling priority comprises:
determining all GBR services needing to be subjected to resource scheduling to form a GBR group, and sequencing the GBR services in the GBR group according to the sequence from small to large of scheduling priority of each GBR service, wherein the sequencing result is the sequence of resource scheduling;
respectively calculating the number of the resource block pairs required by each GBR service at the t time in the scheduling period, and counting the total number N of the resource block pairs required by the GBR group GBR ；
If N GBR ≥N m Then N is allocated according to the ordered result m The GBR service of the unassigned resource block pair performs resource allocation in the next scheduling period; wherein N is m Is a set threshold value;
if N GBR ＜N m And sequentially distributing the needed resource block pairs for all GBR services of the GBR group according to the sequencing result.
9. The flexible high-speed rail wireless access network networking method of claim 7, wherein the performing the scheduling of the resources of Non-GBR traffic comprises:
determining available resource block pairs, and reusing the available resource block pairs to perform resource scheduling of Non-GBR service; the remaining resource block pairs after GBR service resource allocation include the following three cases:
case one: if the resource block pair is not allocated and occupied at all, recalculating the scheduling priority of each Non-GBR service, and allocating the whole resource block pair to a certain Non-GBR service;
and a second case: only 1 resource block is allocated and occupied by two resource blocks in the resource block pair, and then the unallocated resource blocks in different resource block pairs are recombined into a resource block pair to participate in the allocation of Non-GBR service;
case three: and if both resource blocks in the resource block pair are allocated and occupied, no allocation is performed.
10. The method for networking a flexible high-speed rail wireless access network according to claim 9, wherein the Non-GBR service resource scheduling method is as follows:
determining all Non-GBR services needing to be subjected to resource scheduling to form a Non-GBR group, recalculating the scheduling priority of each Non-GBR service, and sequencing the Non-GBR services in the Non-GBR group according to the sequence from small to large of the scheduling priority of each Non-GBR service, wherein the sequencing result is the sequence of resource scheduling;
respectively calculating the number of pairs of resource blocks required by each Non-GBR service in the current scheduling period;
and for the resource block pairs in the first case and the resource block pairs which are formed by recombining the unassigned resource blocks in the different resource block pairs, sequentially assigning the unassigned resource blocks to the corresponding Non-GBR service according to the priority order, delaying the Non-GBR service which is unassigned to the resource block pairs to the next scheduling period, and participating in the resource scheduling of the Non-GBR service in the next scheduling period.
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