CN111432418B - Content caching method and system based on D2D communication in 5G network - Google Patents
Content caching method and system based on D2D communication in 5G network Download PDFInfo
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
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- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/02—Power saving arrangements
- H04W52/0203—Power saving arrangements in the radio access network or backbone network of wireless communication networks
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
- H04W16/22—Traffic simulation tools or models
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/02—Power saving arrangements
- H04W52/0209—Power saving arrangements in terminal devices
- H04W52/0212—Power saving arrangements in terminal devices managed by the network, e.g. network or access point is master and terminal is slave
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
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- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
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Abstract
The invention discloses a content caching method and a content caching system based on D2D communication in a 5G network, wherein in a cell with dense small base stations in the 5G network, a user acquires files cached on other user equipment through D2D communication so as to reduce energy consumption, the cache setting implementation comprises the steps of establishing a network model combining the small base stations and a macro base station, and setting the energy consumption as an optimization target, wherein the energy consumption comprises the energy consumption of the base stations and the energy consumption of the user equipment; and when a user initiates a file request, if a neighbor node caches the file, the file is transmitted through D2D communication. The invention solves the problems of mobile flow increase and huge energy consumption in the 5G network based on the factors of storage capacity limitation, mobility and the like of the equipment.
Description
Technical Field
The present invention relates to the field of communications technologies, and in particular, to a content caching method and system based on D2D communication in a 5G network.
Background
With the continuous update of mobile devices such as smart phones and the like and the mass emergence of various emerging application programs, the mobile data traffic is continuously increased, and a large burden is brought to the traditional network architecture. It is estimated that 2022 year mobile data traffic will reach 77EB per month, with video accounting for approximately four fifths, becoming the primary source of mobile data traffic. In order to meet the increasing network requirements, the next generation mobile communication network system (5G) adopts technologies such as large-scale multiple-input multiple-output, millimeter wave, small base station densification, D2D communication and the like, has the characteristics of high speed, low delay, large capacity, low energy consumption and the like, and can meet the performance requirements under different application scenarios.
The small base station is low-power cellular wireless access equipment, compared with the macro base station, the small base station is small in size and small in coverage range, can cover an area with weak signals of the macro base station so as to guarantee signal quality, and can reuse the same frequency in the same area for multiple times to fully utilize frequency spectrum resources, improve capacity and help the macro base station to shunt. The 5G network realizes the dense deployment of the small base stations, and the small base stations and the macro base stations are combined for use, so that the mobile data traffic is transferred from the macro base stations to the dense small base stations, the pressure of the macro base stations is relieved, and a large amount of energy loss is also brought.
D2D communication in a cellular network is direct communication between two user equipments without base station or core network involvement. In a conventional cellular network, all communication must pass through a base station even if both parties are within communication range of each other. When a user uses high data rate services, such as video, gaming, proximity-aware social networking, etc., the spectral efficiency of the network would be greatly improved if D2D communication could be used. Furthermore, D2D communication can also improve throughput, energy efficiency, fairness, etc. D2D communication in a cellular network is similar to, but different from, mobile ad hoc networks (MANETs) and Cognitive Radio Networks (CRNs). D2D communication in a cellular network is monitored by a central entity and D2D users may operate autonomously only when the cellular network is unavailable. The central entity is only responsible for some control signal transmission, and specific data transmission is completed among users. The participation of the cellular network on the control plane is a key characteristic of the cellular network, and solves a plurality of problems of the mobile ad hoc network and the cognitive radio network, such as blank detection, conflict avoidance and synchronization. In fact, the request repeatability of the user for the content is high, and the caching of the frequently requested content in the user equipment becomes an important means for reducing the backhaul congestion and improving the experience quality. The research of the existing D2D communication caching scheme in the prior art focuses on the design of caching content and the calculation of file popularity, neglects the energy consumption of users and base stations and the development and change of network scenes, and the influence of the energy consumption problem on the network performance in the 5G network is not neglected.
Disclosure of Invention
The invention aims to solve the problems in the prior art, and provides a content caching technical scheme based on D2D communication in a 5G network, which can effectively improve the energy consumption efficiency of the network.
The technical scheme of the invention is a content caching method based on D2D communication in a 5G network, in a cell with dense small base stations in the 5G network, a user acquires files cached on other user equipment through D2D communication so as to reduce energy consumption, and the cache setting implementation process comprises the following steps:
step 1, establishing a network model combining a small base station and a macro base station, wherein the network model comprises a macro base station, a plurality of small base stations and a plurality of user equipment which are respectively m and n in number, the user equipment sends a file request in the random moving process, when the user equipment requests a file, the file with higher popularity is repeatedly requested, the popularity distribution of the file is assumed to obey the zifff law, z files are arranged in a file set F, the files in the set are sequentially in a descending order based on popularity, and the size of the F file is set as SfEach user device independently and randomly accesses the file, and the probability that a certain user device requests the file f is recorded as Pf；
Step 2, setting energy consumption as an optimization target, wherein the energy consumption comprises base station energy consumption and user equipment energy consumption, and the base station energy consumption comprises fixed energy consumption and adaptive energy consumption;
step 3, establishing a user movement model by using a Markov chain, wherein the interior of a cell is divided into m clusters according to the number m of small base stations and the coverage area, and each small base station corresponds to one cluster; modeling the movement of the user equipment among the clusters by using a Markov chain, wherein each state in a corresponding state space represents a cluster which can be reached by a user; let a user equipment have w possible routes in k time slots, which are respectively marked as R1,R2,…,RwThe set R ═ R1,R2,…,Rw-ordering the elements in the set R such that
Wherein the content of the first and second substances,
indicating user equipment performing RvThe probability of the route is obtained according to the probability of moving between two clusters in k continuous time slots;
setting the cache matrix of small base station as X and the cache matrix of user equipment as Y, when the user equipment a requests file f, the communication probability of it and at least one neighbor user containing file f is paf；
Step 4, establishing a total energy consumption model based on the probability Pf、
And pafSolving and calculating the energy consumption value according to a branch and bound method to obtain a cache scheme on the base station and the user equipment,
when a user initiates a file request, if a neighbor node caches the file, the file is transmitted through D2D communication; otherwise, if the small base station caches the file, the file is transmitted through the small base station, and if the small base station and the neighbor node do not cache the file, the file is downloaded through the macro base station.
Furthermore, in step 1, the probability P that a certain user equipment requests the file ffThe definition is as follows,
wherein α is a Zipf index.
Furthermore, in step 2, defining the energy consumption efficiency W of the base station according to the energy consumption of the base stationBSObtaining the energy consumption efficiency W of D2D communication according to the energy consumption of the user equipmentD2D。
Furthermore, in step 3, the communication probability pafThe definition is as follows,
wherein e represents a mathematical constant, ybfIndicating whether user equipment b caches file f, lambdaabA parameter indicating a connection time of the user equipment a and the user equipment b.
Furthermore, in the step 4, the step of,
the total energy consumption model is as follows,
E＝EMBS+ESBS+ED2D
the energy consumption of the D2D communication is
Energy consumption of small base station communication is
The energy consumption of macro base station communication is
In summary, the total energy consumption in the cell is
Where N represents the set of all users in a cell, WMBSAnd WSBSRespectively representing the energy consumption efficiency s ∈ R of the macro base station and the small base stationvRepresents route RvThe small base station s through which it passes.
Moreover, the total calculation energy is time consuming, constrained by the storage capacity of the small base station and the storage capacity of the user equipment.
The invention also provides a content caching system based on D2D communication in the 5G network, which is used for executing the content caching method based on D2D communication in the 5G network.
The invention provides a content caching technical scheme based on D2D for a 5G network from the energy consumption perspective, and the user equipment acquires files in a four-layer structure sequence of local equipment, neighbor equipment, a small base station and a macro base station, adds the limitation of the mobility and the storage capacity of the user in a real scene, is more beneficial to practice, and can reduce the transmission delay and save the energy consumption. Compared with the prior art only considering the cache content, the method and the device fully consider the limiting conditions in the actual scene, and solve the problems of rapid increase of mobile flow and huge energy consumption in the 5G network.
Drawings
Fig. 1 is a schematic diagram of a network model for D2D communication according to an embodiment of the present invention.
Fig. 2 is a flow chart of a method of an embodiment of the present invention.
FIG. 3 is a flow chart of a file request according to an embodiment of the present invention.
Detailed Description
In the invention, under the 5G network environment, the mobility of the user equipment and the limitation of the storage capacity are fully considered, the small base stations and the caching method on the user equipment are set by taking energy saving as an optimization target, and in the small base station intensive cell in the 5G network, the user acquires files cached on other user equipment through D2D communication. The result obtained by the method is more scientific and more accurate. Based on the above, the present invention provides a content caching method in D2D communication, which includes the following steps:
firstly, a network model is established, the invention takes a small base station intensive cell in a 5G network as a research object, secondly, the energy consumption problems of users and a base station are considered, the base station energy consumption comprises two parts of fixed energy consumption and self-adaptive energy consumption, and the energy consumption of user equipment is generated by channel fading during transmission. Then modeling is carried out on the mobility of the user, corresponding mobile models are obtained respectively through analysis of the influence of the mobility on base station communication and D2D communication and Markov chain modeling, and finally the energy consumption problem is converted into an integer planning problem in an operational research theory, so that an automatic solution of the technical problem is realized.
As shown in fig. 2, a content caching method based on D2D communication in a 5G network according to an embodiment of the present invention is implemented by the following specific steps:
step 1: establishing a network model combining a small base station and a macro base station, namely a single-cell network model: as shown in fig. 1, a macro base station, a plurality of small base stations and a plurality of user equipments are located in a cell, and the number of the small base stations and the number of the users are m and n, respectively. The user equipment sends a file request during the random move. When the user equipment requests the file, the file with higher popularity is repeatedly requested, the popularity distribution of the file is assumed to obey zigh law, z files in the file set F are considered, and each user equipment independently and randomly accesses the file.
The specific setup procedure of the embodiment is illustrated as follows:
let there be z files F in the file set F1,F2,…,FzAnd is denoted as F ═ F1,F2,…,FzThe files in the set are in descending order based on popularity, and the F-th file F is setf(hereinafter abbreviated as document f) has a size Sf. Probability P of each user equipment independently and randomly accessing the file, and a certain user equipment requesting the file ffComprises the following steps:
wherein alpha is a Zipf index, and controls the distribution of content popularity. The popularity distribution of the content is different for different Zipf distribution indices. The larger the Zipf index, the greater the probability that the content will be reused.
The file acquisition in the network model of the present invention is divided into three methods, as shown in fig. 3:
when a user initiates a file request, firstly judging whether a neighbor user caches a file, if so, acquiring the file through D2D communication, if not, judging whether the small base station caches the file,
if yes, the small base station and the user communicate to obtain a file;
and if not, acquiring the file through the core network.
Assuming that user a requests file 1, if there is a device caching file 1 within its communication range, the file is directly acquired through D2D communication. If the device without the cache file 1 requests the small base station 1 to which the user A belongs, and if the small base station 1 caches the file 1, the file is directly obtained through small base station-user communication. If the small cell does not cache the file 1, the file 1 needs to be requested to the core network through the macro cell.
Step 2: energy consumption is a key problem in the 5G network, so in addition to considering time delay, throughput and other factors, the energy consumption can be used as an optimization target in the D2D communication in the 5G network. Generally, the energy consumption includes base station energy consumption and user equipment energy consumption.
1) The energy consumption of the base station can be divided into two parts of fixed energy consumption and self-adaptive energy consumption:
EBS＝Efixed+Ead
wherein EBSFor base station energy consumption, EfixedFor a fixed energy consumption, caused by station heat dissipation and other functions, EadFor adaptive energy consumption, depending on the traffic load of the base station, in relation to the transmission power, a linear approximation can be used to model the adaptive energy consumption as:
Ead＝eslope·p
wherein eslopeIs the slope of the "load-energy consumption" of a certain base station, e for different types of base stationsslopeThe values of the small base station and the macro base station are respectively 2.6 and 4.7. p is the transmission power of the base station. Furthermore, the energy consumption efficiency of the base station is defined as follows:
wherein WBSAnd the energy consumption efficiency of the base station is expressed by taking J/bit as a unit. DBSIndicating the amount of data that the base station transmits the file. EBSRepresenting the energy consumption of the base station.
2) The energy consumption of the user equipment is divided into large-scale fading channel energy consumption and small-scale fading channel energy consumption according to the channel model. The transmission path loss model of a large-scale fading channel is d-AD is the communication distance, A is the path loss index, the small-scale fading channel uses the Rayleigh fading channel model, and the channel gain is h; signal-to-noise ratio, SINR, when user equipment a and user equipment b are in D2D communicationabComprises the following steps:
wherein P isdAnd PcRepresenting the transmission power, h, of the D2D user and the cellular user, respectivelydAnd hcRespectively representing the channel gains, D, of the small-scale fading channels of the D2D user and the cellular userabIs the communication distance between a and b, δ2Is the mean of white Gaussian noise, duRepresenting the communication distance of the cellular user. According to the Shannon formula, B is the D2D communication bandwidth, and the energy consumption efficiency W of each single-hop D2D communicationD2DComprises the following steps:
the examples are specifically illustrated below:
the network model is a single cell distributed with a macro base station, a plurality of small base stations and a plurality of users, the cell is a circular area with the radius of 500 meters and the macro base station as a circular point, 20 small base stations and 200 users are arranged in the cell, 500 files are arranged in a file set, and the size of each file is 50 MB. The exponent α of the Zipf distribution is 0.7, the range over which a D2D user can communicate is 30 meters, the user equipment transmit power is 200mW, and the communication bandwidth of the D2D user is 20 MHz. The channel model comprises small-scale Rayleigh fading and large-scale path loss, wherein the path loss factor A is 4, and the mean value delta of white Gaussian noise2Is-174 dBm.
And step 3: user mobility models are built using markov chains: because of the mobility of the user, the invention divides the cell interior into m clusters according to the number m of the small base stations and the coverage area, namely, each small base station corresponds to one cluster, the movement of the user equipment among the clusters is modeled by using a Markov chain, and each state in the state space represents the cluster which can be reached by the user. The inter-cluster movement of a user consists of k steps on a markov chain over k time slots. Order to
Indicating that the user equipment is currently in the cluster ciThe probability of (1) is the same as the initial probability of the Markov chain. Will be provided with
Is defined as state ciAnd cjBetween the twoRate, corresponding to the user in the network scenario, from cluster c in two consecutive time slotsiMove to cluster cjThe probability of (c). When two of the clusters are adjacent to each other,
the value is higher, when the two clusters are farther apart,
smaller, or even zero. Let a user equipment have w possible routes in k time slots, which are respectively marked as R1,R2,…,RwThe set R ═ R1,R2,…,RwDenotes a set of routes for all k steps, the elements in the set R being ordered such that
Wherein the content of the first and second substances,
indicating user equipment performing RvThe probability of the route is determined by the probability of the route,
indicating user equipment performing Rv+1The probability of the route. Wherein a certain element Rv＝{S1,S2,…,SkIs the route RvThe k clusters passed by in the process of the small base station S1,S2,…,SkIn chronological order. For static users, set RvAre always the same. And the user equipment route is RvProbability of (2)
Consists of the probability of moving between two clusters at a time in k consecutive time slots, and the formula is as follows:
wherein
Is the initial probability of the markov chain,
from cluster c in two consecutive time slots for a userjMove to cluster cj+1The probability of (c).
The cache matrix of the small base station is a 0-1 matrix X with m multiplied by z dimensions, wherein m represents the number of the small base stations, and z represents the number of files. Some element X in the matrix Xsf0, meaning that the small base station s does not have the cache file f, xsf1, indicates that the small base station s buffers the file f. When the user equipment requests the files stored on the small base station in the random moving process, the service can be provided through the cache on the small base station.
The mobility of the user equipment also influences the contact time between the devices in the D2D communication, and if the user equipment a can be connected with the user equipment b, the user equipment a and the user equipment b can carry out file transmission through D2D communication, and the connection time between the user equipment a and the user equipment b is subject to the parameter lambdaabOf (d) exponential distribution, λabThe value settings are subject to a continuous probability function Γ (4.43, 1/1088). The cache matrix of the user equipment is a 0-1 matrix Y with n multiplied by z dimensions, wherein n represents the number of the user equipment, and z represents the number of files. Wherein y isafWhen the value is 0, the user equipment a is indicated to have the cache file f, and when the value is yafWhen 1, it indicates that the user equipment a caches the file f. When the user equipment a requests the file f, the communication probability of the user equipment a and at least one neighbor user containing the file f is as follows:
wherein e represents a mathematical constant, ybfIndicating whether user equipment b caches file f, lambdaabA parameter indicating a connection time of the user equipment a and the user equipment b.
The specific implementation process of the embodiment is as follows:
setting the slot length equal to 40 secondsK is set to 3, i.e., the file transfer is completed within 120 seconds. The storage capacity of the small base station is 1G, and the storage capacity of the user equipment is 200M. The mobile user can carry out the communication between the devices when in the transmission range, and the file transmission can be carried out when the two user devices are in the communication time. In particular, in a network of n user devices, the location of any two user a and b communication times can be modeled as having an intensity of λabThe poisson process of (a). To simplify the processing, let λ be the sum of the timelines of the different pairs of devices, assuming that they are independentabReferred to as the communication rate between users a and b, which can be estimated from historical data, the results of the present invention are tested on a real data set.
And 4, step 4: the cache is divided into three parts according to the cache position, and when a user initiates a file request, if a neighbor node caches the file, the file is transmitted through D2D communication. Otherwise, if the small base station caches the file, the file is transmitted through the small base station, and if the small base station and the neighbor node do not cache the file, the file is downloaded through the macro base station. Thus, the total energy consumption formula is as follows:
E＝EMBS+ESBS+ED2D
based on the above analysis, the energy consumption of D2D communication is
Energy consumption of small base station communication is
The energy consumption of macro base station communication is
In summary, the total energy consumption in the cell is
Where N represents the set of all users in a cell, WMBSAnd WSBSThe energy consumption efficiency of the macro base station and the small base station are respectively expressed, which can be seen in the above WBSObtaining by calculation; wD2DFor the energy consumption efficiency of D2D communication, see step 1; pfIndicating the probability that file f is requested, SfRepresenting the file size, see step 1; s is formed by RvRepresents route RvPassing small base station s, Rve.R represents a certain route R in the route set Rv。
In addition, there is a constraint condition for calculating total energy consumption, and because the storage capacity of the equipment is limited in practical situations, the invention considers that the buffer space of the small base stations and the user equipment is limited, and the total amount of buffer contents in each small base station cannot exceed the storage capacity of the small base station. Similarly, the total amount of cache content per user device cannot exceed the storage capacity of the device. The following two formulas are constraints in calculating total energy consumption:
wherein M isSBSRepresenting the buffer capacity, M, of a single small base stationuserRepresenting the buffer capacity of a single user equipment.
The specific implementation process of the embodiment is as follows:
according to the formula of total energy consumption in a cell, variable value ranges in the formula are all integers, so that the method is a typical integer programming problem, and after basic data are input, the energy consumption value is solved and calculated according to a branch and bound method to obtain cache schemes X and Y on a base station and user equipment. The method comprises the following specific steps:
1) and (3) ignoring the constraint condition, starting traversing all values of the matrix X and the matrix Y, and taking the values of the elements of the matrix X and the matrix Y as 0 or 1.
2) And calculating the traversed energy consumption value.
If the energy consumption value is less than that of the existing feasible solution or no feasible solution exists, executing 3);
if the energy consumption value is larger than or equal to the energy consumption value of the existing feasible solution, pruning is carried out, namely, the following steps are not continuously executed, the traversal is continuously carried out, and the step 2) is executed.
3) And checking whether the existing caching method meets all the constraint conditions.
If a constraint condition is not met, continuous inspection is not needed, the current cache method is not feasible, and traversal is continued;
if all constraints are met, the caching method and energy consumption value are updated. If some bits of X or Y in the current solution are changed from 0 to 1, the target value is certainly larger than that of the feasible solution, pruning is carried out, and traversal is continued.
In specific implementation, the method provided by the invention can realize automatic operation flow based on software technology. System devices for operating the process flow are also intended to be within the scope of the invention.
The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.
Claims (5)
1. A content caching method based on D2D communication in a 5G network is characterized in that: in a cell with dense small base stations in a 5G network, a user acquires files cached on other user equipment through D2D communication so as to reduce energy consumption, and the cache setting implementation process comprises the following steps,
step 1, establishing a network model combining a small base station and a macro base station, wherein the network model comprises a macro base station, a plurality of small base stations and a plurality of user equipment which are arranged in a cell, the number of the small base stations and the number of the users are m and n respectively, the user equipment sends a file request in a random moving process, and the user equipment requests a fileWhen the file with higher popularity is requested repeatedly, the popularity distribution of the file is assumed to obey the zigh law, z files exist in a file set F, the files in the set are sequentially in a descending order based on the popularity, and the size of the F-th file is set as SfEach user device independently and randomly accesses the file, and the probability that a certain user device requests the file f is recorded as Pf；
Step 2, setting energy consumption as an optimization target, wherein the energy consumption comprises base station energy consumption and user equipment energy consumption, the base station energy consumption comprises fixed energy consumption and adaptive energy consumption, and the expression is as follows,
EBS＝Efixed+Ead
wherein EBSFor base station energy consumption, EfixedFor a fixed energy consumption, caused by station heat dissipation and other functions, EadFor adaptive energy consumption, depending on the traffic load of the base station, related to the transmission power, the adaptive energy consumption is modeled as:
Ead＝eslope·p
wherein eslopeIs the slope of the "load-energy consumption" of a certain base station, p is the transmission power of the base station;
the energy consumption efficiency of the base station is defined as follows:
wherein WBSRepresenting the energy consumption efficiency of the base station, DBSIndicating the amount of data of the file transmitted by the base station, EBSRepresents the energy consumption of the base station;
step 3, establishing a user movement model by using a Markov chain, wherein the interior of a cell is divided into m clusters according to the number m of small base stations and the coverage area, and each small base station corresponds to one cluster; modeling the movement of the user equipment among the clusters by using a Markov chain, wherein each state in a corresponding state space represents a cluster which can be reached by a user; let a user equipment have w possible routes in k time slots, which are respectively marked as R1,R2,…,RwThe set R ═ R1,R2,…,Rw-ordering the elements in the set R such that
Wherein the content of the first and second substances,
indicating user equipment performing RvThe probability of the route is obtained according to the probability of moving between two clusters in k continuous time slots;
setting the cache matrix of small base station as X and the cache matrix of user equipment as Y, when the user equipment a requests file f, the communication probability of it and at least one neighbor user containing file f is paf；
The cache matrix of the small base station is a 0-1 matrix X with m multiplied by z dimensionality, m represents the number of the small base stations, and z represents the number of files; some element X in the matrix Xsf0, meaning that the small base station s does not have the cache file f, xsf1, the small base station s caches the file f;
the cache matrix of the user equipment is a 0-1 matrix Y with n multiplied by z dimensionality, wherein n represents the number of the user equipment, and z represents the number of files; some element Y of the matrix YafWhen the value is 0, the user equipment a is indicated to have the cache file f, and when the value is yafWhen the value is 1, the file f is cached by the user equipment a;
step 4, establishing a total energy consumption model based on the probability Pf、
And pafSolving and calculating the energy consumption value according to a branch and bound method to obtain a cache scheme on the base station and the user equipment,
when a user initiates a file request, if a neighbor node caches the file, the file is transmitted through D2D communication; otherwise, if the small base station caches the file, the small base station transmits the file, and if the small base station and the neighbor node do not cache the file, the macro base station downloads the file;
the total energy consumption model is as follows,
E＝EMBS+ESBS+ED2D
the energy consumption of the D2D communication is
Energy consumption of small base station communication is
The energy consumption of macro base station communication is
In summary, the total energy consumption in the cell is
Where N represents the set of all users in a cell, WMBSAnd WSBSRespectively representing the energy consumption efficiency s ∈ R of the macro base station and the small base stationvRepresents route RvThe small base station s through which it passes.
2. The content caching method based on D2D communication in the 5G network according to claim 1, wherein: in step 1, the probability P of a certain user equipment requesting a file ffThe definition is as follows,
wherein α is a Zipf index.
3. The content caching method based on D2D communication in the 5G network according to claim 2, wherein the method comprisesIs characterized in that: in step 2, defining the energy consumption efficiency W of the base station obtained according to the energy consumption of the base stationBSObtaining the energy consumption efficiency W of D2D communication according to the energy consumption of the user equipmentD2D；
The energy consumption efficiency of the base station is defined as follows:
wherein WBSRepresenting the energy consumption efficiency of the base station, DBSIndicating the amount of data of the file transmitted by the base station, EBSRepresents the energy consumption of the base station;
energy consumption efficiency W of D2D communicationD2DComprises the following steps:
wherein P isdDenotes the transmission power of D2D user, B is D2D communication bandwidth, SINRabIs the signal-to-noise ratio when user equipment a and user equipment b are in D2D communication.
4. The content caching method based on D2D communication in the 5G network according to claim 3, wherein: in step 3, the communication probability pafThe definition is as follows,
wherein e represents a mathematical constant, ybfIndicating whether user equipment b caches file f, lambdaabA parameter indicating a connection time of the user equipment a and the user equipment b.
5. Content caching method based on D2D communication in a 5G network according to claim 1 or 2 or 3 or 4, wherein: and calculating the total energy consumption by taking the storage capacity of the small base station and the storage capacity of the user equipment as constraints.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108471609A (en) * | 2018-03-17 | 2018-08-31 | 西南大学 | Caching dispositions method based on D2D cognition wireless networks |
| CN109511137A (en) * | 2018-11-29 | 2019-03-22 | 哈尔滨工程大学 | A kind of big flow communication information interaction processing method based on D2D caching |
| WO2020053781A1 (en) * | 2018-09-12 | 2020-03-19 | Telefonaktiebolaget Lm Ericsson (Publ) | Online power control in d2d networks |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102244900B (en) * | 2011-07-15 | 2014-01-22 | 上海华为技术有限公司 | Method, device and system for synchronizing cached data heat value, and distributed caching method |
| GB2537623A (en) * | 2015-04-20 | 2016-10-26 | Fujitsu Ltd | Content delivery over D2D links |
| WO2017063670A1 (en) * | 2015-10-13 | 2017-04-20 | Huawei Technologies Co., Ltd. | A base station and a method for managing the distribution of a plurality of files to a user equipment |
| CN107295619B (en) * | 2017-08-10 | 2020-01-10 | 北京邮电大学 | Base station dormancy method based on user connection matrix in edge cache network |
| CN109587776B (en) * | 2018-12-07 | 2021-03-30 | 东南大学 | D2D-assisted joint optimization method for base station dormancy and cooperative caching in ultra-dense network |
| CN109714790A (en) * | 2019-01-23 | 2019-05-03 | 南京邮电大学 | A kind of edge cooperation caching optimization method based on user mobility prediction |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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| WO2020053781A1 (en) * | 2018-09-12 | 2020-03-19 | Telefonaktiebolaget Lm Ericsson (Publ) | Online power control in d2d networks |
| CN109511137A (en) * | 2018-11-29 | 2019-03-22 | 哈尔滨工程大学 | A kind of big flow communication information interaction processing method based on D2D caching |
Non-Patent Citations (1)
| Title |
|---|
| "多缓存容量场景下的D2D内容缓存布设优化方案";龙彦汕等;《计算机应用》;20180108;全文 * |
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