CN114666842B - Collaborative caching method based on vehicle clustering - Google Patents
Collaborative caching method based on vehicle clustering Download PDFInfo
- Publication number
- CN114666842B CN114666842B CN202210161140.1A CN202210161140A CN114666842B CN 114666842 B CN114666842 B CN 114666842B CN 202210161140 A CN202210161140 A CN 202210161140A CN 114666842 B CN114666842 B CN 114666842B
- Authority
- CN
- China
- Prior art keywords
- vehicle
- cluster
- cache
- roadside unit
- content
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 51
- 241000854291 Dianthus carthusianorum Species 0.000 claims abstract description 116
- 238000004891 communication Methods 0.000 claims abstract description 77
- 230000005540 biological transmission Effects 0.000 claims abstract description 16
- 239000003016 pheromone Substances 0.000 claims description 37
- 239000000872 buffer Substances 0.000 claims description 30
- 239000011159 matrix material Substances 0.000 claims description 21
- 230000007704 transition Effects 0.000 claims description 16
- 239000007853 buffer solution Substances 0.000 claims description 5
- 238000004364 calculation method Methods 0.000 claims description 3
- 238000005457 optimization Methods 0.000 abstract description 2
- 239000000243 solution Substances 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Abstract
The invention discloses a collaborative caching method based on vehicle clustering, which can fully utilize limited caching resources in a vehicle-mounted self-organizing network and effectively reduce time delay and cost when a vehicle requests content. The method comprises the following specific steps: firstly, clustering vehicles according to the speed and the position of the vehicles and the number of neighbor vehicles, after a mobile vehicle sends a content request, searching the content according to the sequence of a cluster head, an adjacent cluster, a roadside unit (RSU), and a non-adjacent cluster, when the local cache content is found, returning the content to the requesting vehicle according to an original transmission path, wherein the communication between the adjacent clusters is carried out in a V2V mode, and the communication between the non-adjacent clusters uses the roadside unit as a relay. And then calculating the time delay and cost required by each content acquisition mode, constructing an optimization problem of the joint minimization of the time delay and the cost, and then solving the problem by adopting an ant colony algorithm to obtain an optimal cache placement scheme.
Description
Technical Field
The invention relates to the technical field of communication, in particular to a collaborative caching method based on vehicle clustering.
Background
With the development of Intelligent Transportation Systems (ITS), drivers and passengers need not only traffic information but also more other contents such as in-car entertainment and mobile advertising, which put great stress on the in-car network. The edge caching is to deploy caching at the edge of the system, introduce edge caching technology in the vehicle-mounted network, and cache the content in the roadside units and the vehicles, so that the probability of acquiring the content from a remote content server can be reduced, the content acquisition time delay is effectively reduced, and the pressure of the vehicle-mounted network is relieved.
The traditional caching method in the vehicle-mounted network does not consider the cooperation between the mobile vehicle and the roadside units, so that the success rate of the request content of the whole network is low, and the vehicle clustering method is not considered, so that the communication link in the vehicle-mounted network is disordered. Therefore, the collaborative caching between the mobile vehicle and the roadside units is considered, and the content is allocated in the vehicle and the roadside units RSU in a collaborative manner, so that the diversity of the cached content in the network is improved, the redundancy is reduced, and the time delay and the cost for acquiring the cached content are reduced. Meanwhile, a vehicle clustering method is introduced, so that the stability of communication in the vehicle-mounted self-organizing network is improved.
Disclosure of Invention
The purpose of the invention is that: the method for collaborative caching based on vehicle clustering is characterized in that the time delay and cost of a vehicle when requesting for caching content are reduced by utilizing limited cache resources in a vehicle-mounted self-organizing network.
In order to achieve the above functions, the invention designs a collaborative caching method based on vehicle clustering, based on caching content stored in each roadside unit RSU on a target road section or in a cluster head of each vehicle cluster in a communication coverage area of each roadside unit RSU, when a vehicle in a vehicle cluster requests caching content, the vehicle in the vehicle cluster requests the cluster head of the vehicle cluster to which the vehicle belongs, if the cluster head of the vehicle cluster to which the vehicle belongs does not have the requested content, the vehicle sends out requests to cluster heads of other vehicle clusters in the communication coverage areas of the roadside unit RSU and the roadside unit RSU, and when the vehicle sends out requests to the cluster heads of the vehicle clusters not adjacent to the vehicle cluster to which the vehicle cluster belongs, the roadside unit RSU is required to be used as a relay, the following steps are executed according to a preset period to finish the placement of caching content positions, so that the vehicle obtains caching content from the cluster head of the vehicle cluster or the roadside unit RSU, and the time delay and cost in the caching content obtaining process are minimized;
S1, dividing vehicle clusters in the communication coverage area of each roadside unit RSU according to each roadside unit RSU on a target road section, wherein the communication coverage area of each roadside unit RSU at least comprises one vehicle cluster, and each vehicle cluster at least comprises one vehicle;
s2, initializing vehicle information: for each vehicle in each vehicle cluster on a target road section, taking other vehicles in a vehicle communication range as neighbor vehicles, and acquiring the number N of the neighbor vehicles, the average distance d between the vehicles and each neighbor vehicle and the sum v d of the speed differences between the vehicles and each neighbor vehicle;
S3, respectively calculating the weight of each vehicle in the vehicle cluster to which the vehicle belongs, if the weight of the vehicle is greater than the weight of each vehicle in the vehicle cluster to which the vehicle belongs, taking the vehicle as a cluster head of the vehicle cluster, otherwise, taking the vehicle as a cluster member of the vehicle cluster;
S4, constructing a delay function for acquiring the cache content and a total cost function for acquiring the cache content according to different methods for acquiring the cache content based on a method for acquiring the cache content by a vehicle from a cluster head of a vehicle cluster or a roadside unit (RSU) of a communication range to which the vehicle belongs;
s5, constructing a delay and cache content total cost acquisition minimization objective function and constraint conditions based on the delay function and the cache content total cost acquisition function;
s6, constructing a caching scheme sample, solving a delay and cache content total cost obtaining minimization objective function by adopting an ant colony algorithm, and obtaining delay corresponding to the caching scheme sample, cache content total cost obtaining, pheromone, heuristic information and transition probability corresponding to the caching scheme sample;
S7, taking the minimum time delay and the total cost of the obtained cache content as targets, obtaining the cache scheme sample which minimizes the time delay and the total cost of the obtained cache content through the participation iteration of each cache scheme sample, and completing the placement of the cache content position based on the cache scheme sample.
As a preferred technical scheme of the invention: in the step S2, for the kth vehicle in the vehicle cluster, denoted by V k, the average distance d between the target vehicle V k and each neighboring vehicle is as follows:
Where x 1 and x k represent the abscissa of vehicle V 1 and vehicle V k, respectively, and y 1 and y k represent the ordinate of vehicle V 1 and vehicle V k, respectively;
The sum V d of the speed differences between the vehicle V k and each neighboring vehicle is as follows:
Where V 1 and V k represent the speeds of vehicle V 1 and vehicle V k, respectively.
As a preferred technical scheme of the invention: in the step S3, the weight calculation method of each vehicle in the vehicle cluster to which the vehicle V k belongs is as follows:
wherein, w 1、w2、w3 has the following relation:
w1+w2+w3＝1
Wherein w is the weight of the vehicle, w 1 is the weight factor of the number of neighbor vehicles, w 2 is the weight factor of the average distance between the vehicle V k and each neighbor vehicle, and w 3 is the weight factor of the sum of the speed differences between the vehicle V k and each neighbor vehicle;
as a preferred technical scheme of the invention: the step of constructing the delay function for obtaining the cache content and the step of obtaining the total cost function of the cache content in the step S4 are as follows:
s41: for any vehicle in any vehicle cluster in the communication coverage area of each roadside unit RSU on the target road section, constructing a delay function T 1 for the vehicle to acquire cache contents from a cluster head of the vehicle cluster to which the vehicle belongs:
Wherein V i,j,k is the kth vehicle in the jth vehicle cluster in the communication coverage of the ith roadside unit RSU on the target road section, V i,j,1 is the cluster head of the vehicle cluster to which the vehicle V i,j,k belongs, and i epsilon {1,2,3, …, N R},NR are the total number of the roadside units RSU on the target road section; j epsilon {1,2,3, …, N C},NC is the total number of vehicle clusters in the communication coverage of the i-th roadside unit RSU; k is {1,2,3, …, n }, n being the total number of vehicles in the jth vehicle cluster; q is the number of the cache content requested by the vehicle in the cache content set, Q is {1,2,3, …, Q }, Q is the total number of the cache content in the cache content set; s q is the ziff distribution parameter of the qth cache content in the cache content set, For the bandwidth between the vehicle V i,j,k and the cluster head V i,j,1 of the vehicle cluster to which it belongs,The signal-to-interference-and-noise ratio between the vehicle V i,j,k and the cluster head V i,j,1 of the vehicle cluster to which the vehicle V i,j,k belongs;
Wherein, The formula is as follows:
In the method, in the process of the invention, For the transmit power of the cluster head V i,j,1,For the channel power gain between the vehicle V i,j,k and the cluster head V i,j,1 of the vehicle cluster to which it belongs, m is the mth vehicle in the vehicle cluster to which the vehicle V i,j,k belongs,To represent the coefficients of interference of communication between the cluster head V i,j,1 and the vehicle V i,j,k by other vehicles in the vehicle cluster to which the vehicle V i,j,k belongs,Indicating that there is an interference present and,Sigma 2 is the noise power, which indicates that no interference exists;
S42: when the vehicle V i,j,k acquires the cache content from the adjacent vehicle cluster in the communication coverage of the roadside unit RSU of the communication range for any one vehicle V i,j,k in the communication coverage of the roadside unit RSU of the target road segment, communication connection is established among the vehicle V i,j,k, the cluster head V i,j,1 of the vehicle cluster to which the vehicle V i,j,k belongs, and the cluster head of the adjacent vehicle cluster of the vehicle V i,j,k, the cache content is transmitted from the cluster head of the adjacent vehicle cluster of the vehicle V i,j,k, through the cluster head V i,j,1 of the vehicle cluster to which the vehicle V i,j,k belongs, to the vehicle V i,j,k, and the time delay function T 2 of the vehicle V i,j,k acquiring the cache content from the cluster head of the adjacent vehicle cluster is constructed:
where o is the adjacent vehicle cluster of vehicle cluster j, V i,o,1 is the cluster head of vehicle cluster o, For the bandwidth between the cluster head V i,j,1 of the vehicle cluster j and the cluster head V i,o,1 of the vehicle cluster o,Is the signal-to-interference-and-noise ratio between the cluster head V i,j,1 and the cluster head V i,o,1;
Wherein, The formula is as follows:
In the method, in the process of the invention, For the transmit power of the cluster head V i,o,1,Channel power gain between cluster head V i,j,1 and cluster head V i,o,1;
S43: when the vehicle V i,j,k acquires the cache content from the roadside unit RSU for any vehicle V i,j,k in any one of the communication coverage areas of the roadside unit RSUs on the target road segment, communication connection is established between the vehicle V i,j,k, the cluster head V i,j,1 of the vehicle cluster to which the vehicle V i,j,k belongs, and the roadside unit RSUs, the cache content is transmitted from the roadside unit RSUs to the vehicle V i,j,k through the cluster head V i,j,1 of the vehicle cluster to which the vehicle V i,j,k belongs, and a time delay function T 3 for the vehicle V i,j,k to acquire the cache content from the roadside unit RSUs is constructed:
Wherein R i represents an i-th roadside unit RSU on the target road section, For the bandwidth between cluster head V i,j,1 and roadside unit RSUR i,Is the signal-to-interference-and-noise ratio between the cluster head V i,j,1 and the roadside unit RSUR i;
Wherein, The formula is as follows:
In the method, in the process of the invention, For the transmission power of the roadside unit RSUR i,Channel gain between cluster head V i,j,1 and roadside unit RSUR i;
S44: aiming at a vehicle V i,j,k in a vehicle cluster in the communication coverage area of a roadside unit RSU on a target road section, when the vehicle V i,j,k acquires cache contents from non-adjacent vehicle clusters in the communication coverage area of the roadside unit RSU in the communication range, the vehicle V i,j,k completes communication through the relay of the roadside unit RSU, and a delay function T 4 of acquiring the cache contents from the non-adjacent vehicle clusters through the roadside unit RSU is constructed by the vehicle V i,j,k:
Where ρ 1 represents a vehicle cluster that is not adjacent to the vehicle cluster j, A cluster head representing a vehicle cluster ρ 1,Is a cluster headThe bandwidth between the road side unit RSUR i,Is a cluster headSignal-to-interference-and-noise ratio with roadside unit RSUR i;
S45: based on the cache cost C C of each cache content and the transmission cost C T of the cache content, constructing a cache content total cost function C as follows:
C＝CC+CT
wherein, the cache cost C C of the cache content is as follows:
CC＝CRSU·CSR+CV·CSV
Wherein, C RSU is the initial cache content capacity of the RSU of the preset roadside unit, C V is the initial cache content capacity of the preset vehicle, C SV is the cache content cost of the preset vehicle, and C SR is the cache content cost of the RSU of the preset roadside unit;
Wherein, the transmission cost C T of the cache content is as follows:
CT＝CqR·CRR+CqV·CVV
Wherein, C RR is the transmission cost of a buffer content transmitted by the RSU, C VV is the transmission cost of a buffer content transmitted by the vehicle, C qR is the total number of buffer contents transmitted by the RSU, and C qV is the total number of buffer contents transmitted by the vehicle.
As a preferred technical scheme of the invention: the steps of minimizing the objective function and the constraint condition by time delay and obtaining the total cost of the cache content in the step S5 are as follows:
s51: respectively constructing a cache placement matrix based on each cache content and the placement mode of the cache content The formula is as follows:
In the cache placement matrix Lines 1 to Q of (1) respectively represent 1 st to Q th cache contents, and cache placement matrixWherein the 1 st column represents a roadside unit (RSU), and the 2 nd to N C +1 st columns represent 1 st to N C th vehicle clusters, respectively; matrix placement for cacheEach node in (a)When the node is located, the cache content corresponding to the line of the node is stored in the cache position corresponding to the column of the node,When the cache content corresponding to the line where the node is located is not stored in the cache position corresponding to the column where the node is located;
s52: based on time delay function for obtaining cache content, total cost function for obtaining cache content and cache placement matrix The minimum objective function P 1 for constructing the delay and obtaining the total cost of the cache contents is as follows:
Wherein W T is a weight coefficient for time delay, T is a time delay function corresponding to a mode of acquiring cache contents according to a vehicle, and W C is a weight coefficient for cost;
the constraint that the delay and the total cost of obtaining the cache contents minimize the objective function is as follows:
(1)
(2)
(3)
(4)
in the formula, x represents a cache placement matrix One of 1 st to N C +1 st columns, y represents a cache placement matrixOne of the 2 nd to N C +1 th columns, S RSU is a preset roadside unit (RSU) storage capacity, and S V is a preset vehicle storage capacity.
As a preferred technical scheme of the invention: in the step S6, a caching scheme sample is constructed, an ant colony algorithm is adopted to solve a delay and obtaining a caching content total cost minimization objective function, and a specific method for obtaining the delay and obtaining the caching content total cost corresponding to the caching scheme sample, and the pheromone, heuristic information and transition probability corresponding to the caching scheme sample is as follows:
S61, respectively using buffer storage placement matrixes corresponding to different buffer storage placement modes Constructing a buffer placement scheme sample, wherein one buffer placement scheme sample corresponds to one ant in the ant colony algorithm, different buffer placement scheme samples participate in iteration in the ant colony algorithm, and the pheromone of each ant in the iteration is calculated, wherein the pheromone of the t iteration of the b-th ant is τ b (t), and the pheromone of the t+1st iteration is τ b (t+1) as follows:
τb(t+1)＝(1-ρ2)·τb(t)+Xb
Wherein ρ 2 is a pheromone attenuation coefficient, 1- ρ 2 represents the volatilization condition of the pheromone after one iteration, χ b is the pheromone left by the cache placement scheme sample corresponding to the b-th ant, and χ b is as follows:
Wherein T (b) is a time delay function of a buffer solution sample corresponding to the b-th ant, and C (b) is a total cost function of buffer contents of the buffer solution sample corresponding to the b-th ant;
s62, based on an ant colony algorithm, heuristic information of each ant in iteration is calculated as follows:
wherein α b is heuristic information of the b-th ant, β (b) represents uniformity of caching content in the vehicle and the roadside unit RSU, and β (b) is as follows:
Wherein, C RSU (b) is the initial cache content capacity of the preset roadside unit RSU of the cache scheme sample corresponding to the b-th ant, and C V (b) is the preset vehicle cache content cost of the cache scheme sample corresponding to the b-th ant;
s63, calculating the transition probability of each ant based on pheromone and heuristic information of each ant in iteration, wherein the transition probability is as follows:
Wherein P (b) is the transition probability of the b-th ant, u is the influence coefficient of the pheromone on the selected cache placement scheme, v is the influence coefficient of heuristic information on the selected cache placement scheme, For the pheromone of the b-th ant based on the influence coefficient u,For heuristic information of the b-th ant based on the influence coefficient v, c is another ant,Based on the pheromone of the c-th ant affecting the coefficient u,Is heuristic information of the c-th ant based on the influence coefficient v.
As a preferred technical scheme of the invention: and step S7, constructing a cache placement scheme in the next iteration based on the transition probability, updating pheromone, heuristic information and the transition probability, stopping iteration when the iteration number reaches the preset maximum iteration number, recording the time delay and the total cost of the requested content corresponding to the cache placement scheme by taking the cache placement scheme corresponding to the last iteration as the cache placement scheme with the minimum time delay and the minimum total cost of the requested content, and finishing placement of the cache content position.
The beneficial effects are that: the advantages of the present invention over the prior art include:
1. the invention optimizes the cache placement scheme by taking the minimum objective function of delay and acquisition of the total cost of the cache content as an optimization target and adopting the thought of an ant colony algorithm so as to obtain the cache content placement scheme with minimum delay and request content total cost.
2. The invention introduces the vehicle clustering method and improves the stability of the communication link in the vehicle-mounted self-organizing network.
3. The invention provides a collaborative caching method, which is used for collaborative caching of content in a mobile vehicle and a roadside unit (RSU), wherein the vehicle can acquire cached content from a cluster head or the RSU, adjacent vehicle clusters communicate in a V2V mode, and the roadside unit RSU is used as a relay for communication between non-adjacent vehicle clusters, so that the time delay and cost for acquiring the content are effectively reduced.
Drawings
FIG. 1 is a schematic diagram of a system model of a collaborative caching method based on vehicle clustering according to an embodiment of the present invention;
Fig. 2 is a flowchart of a collaborative caching method based on vehicle clustering according to an embodiment of the present invention.
Detailed Description
The invention is further described below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical aspects of the present invention, and are not intended to limit the scope of the present invention.
Referring to fig. 1, in the collaborative caching method based on vehicle clustering provided by the embodiment of the invention, a target road section is a unidirectional road with a length of 10km, roadside units RSUs on the target road section are uniformly distributed, vehicles are randomly distributed, cache contents are stored in each roadside unit RSU on the target road section or cluster heads of each vehicle cluster in a communication coverage area of each roadside unit RSU, each roadside unit RSU corresponds to a preset vehicle storage capacity, each vehicle corresponds to a preset vehicle storage capacity, clustering is performed on each vehicle, each vehicle can request cache contents in a V2V or V2R mode, namely, when a vehicle in a vehicle cluster requests cache contents, firstly requests a cluster head of the vehicle cluster to which the vehicle cluster belongs, if no requested contents are in the cluster heads of the vehicle cluster to which the vehicle cluster belongs, requests the cluster heads of other vehicle clusters in a communication coverage area of the roadside unit RSU or the roadside unit RSU, when the vehicle requests the cluster heads of the vehicles not adjacent to the vehicle cluster to which the vehicle cluster belongs, the vehicle RSU needs to use the roadside unit RSU as a relay, and when the vehicle cluster heads of the roadside unit RSU and the vehicle cluster heads need to acquire no remote service contents from the cluster heads of the vehicle cluster heads;
referring to fig. 2, the following steps are performed according to a preset period to finish the placement of the cache content position, so that the vehicle acquires the cache content from the cluster head or the roadside unit RSU of the vehicle cluster, and the time delay and the cost in the process of acquiring the cache content are minimized;
s1, respectively aiming at each roadside unit RSU on a target road section, dividing vehicle clusters in the communication coverage area of each roadside unit RSU, wherein the communication coverage area of each roadside unit RSU at least comprises one vehicle cluster, and each vehicle cluster at least comprises one vehicle.
S2, initializing vehicle information: and respectively aiming at each vehicle in each vehicle cluster on the target road section, taking other vehicles in the vehicle communication range as neighbor vehicles, and acquiring the number N of the neighbor vehicles, the average distance d between the vehicles and each neighbor vehicle and the sum v d of the speed differences between the vehicles and each neighbor vehicle.
For the kth vehicle in the vehicle cluster, denoted by V k, the average distance d of the target vehicle V k from each neighboring vehicle is as follows:
Where x 1 and x k represent the abscissa of vehicle V 1 and vehicle V k, respectively, and y 1 and y k represent the ordinate of vehicle V 1 and vehicle V k, respectively;
The sum V d of the speed differences between the vehicle V k and each neighboring vehicle is as follows:
Where V 1 and V k represent the speeds of vehicle V 1 and vehicle V k, respectively.
S3, calculating the weight of each vehicle in the vehicle cluster to which the vehicle belongs, if the weight of the vehicle is larger than the weight of each vehicle in the vehicle cluster to which the vehicle belongs, taking the vehicle as a cluster head of the vehicle cluster, otherwise, taking the vehicle as a cluster member of the vehicle cluster, and finishing clustering when the number of the vehicles in the vehicle cluster reaches a preset threshold value.
The number of neighbor vehicles around the vehicle represents the number of other vehicles in the communication range of the vehicle, the average distance between the vehicle and the neighbor represents the average Euclidean distance between the vehicle and the other vehicles in the communication range of the vehicle, and the more the neighbor vehicles of the vehicle are, the smaller the average distance between the neighbor vehicles is, so that the vehicle is more suitable for being selected as a cluster head. The speed difference between the vehicle and the neighbor vehicle can be used for evaluating the stability of the cluster, and the closer the speed between the cluster head and the cluster member is, the longer the time of the cluster member in the vehicle cluster is, and the higher the success rate of communication is. The smaller the sum of the speed differences between the vehicle and the neighbors, the more suitable the vehicle is for being selected as a cluster head;
the weight calculation method of each vehicle in the vehicle cluster to which the vehicle V k belongs is as follows:
wherein, w 1、w2、w3 has the following relation:
w1+w2+w3＝1
Wherein w is the weight of the vehicle, w 1 is the weight factor of the number of neighbor vehicles, w 2 is the weight factor of the average distance between the vehicle V k and each neighbor vehicle, and w 3 is the weight factor of the sum of the speed differences between the vehicle V k and each neighbor vehicle;
S4, constructing a delay function for acquiring the cache contents and a total cost function for acquiring the cache contents according to different methods for acquiring the cache contents based on a method for acquiring the cache contents by the vehicle from a cluster head of a vehicle cluster or a roadside unit (RSU) of a communication range to which the vehicle belongs.
The steps of constructing a delay function for obtaining the cache content and a total cost function for obtaining the cache content are as follows:
S41: aiming at any vehicle in any vehicle cluster in the communication coverage area of each roadside unit RSU on a target road section, the cache content requested by the vehicle follows ziff distribution, and the request probability P q of each cache content is as follows:
wherein S is a ziff distribution parameter, Q is the number of the cache content requested by the vehicle in the cache content set, Q epsilon {1,2,3, …, Q }, Q is the total number of the cache content in the cache content set, The q-th cache content request times are distributed for the base Yu Jifu, the higher the S is, the higher the probability of occurrence of popular cache content is indicated, the higher the corresponding request frequency is, and the higher the probability of caching the cache content is;
When a vehicle acquires cache contents from a cluster head of a vehicle cluster to which the vehicle belongs from the vehicle, communication connection is only required to be established between the vehicle and the cluster head of the vehicle cluster to which the vehicle belongs, and the cluster head of the vehicle cluster acquires a delay function T 1 of the cache contents:
Wherein V i,j,k is the kth vehicle in the jth vehicle cluster in the communication coverage of the ith roadside unit RSU on the target road section, V i,j,1 is the cluster head of the vehicle cluster to which the vehicle V i,j,k belongs, and i epsilon {1,2,3, …, N R},NR are the total number of the roadside units RSU on the target road section; j epsilon {1,2,3, …, N C},NC is the total number of vehicle clusters in the communication coverage of the i-th roadside unit RSU; k is {1,2,3, …, n }, n being the total number of vehicles in the jth vehicle cluster; s q is the ziff distribution parameter of the qth cache content in the cache content set, For the bandwidth between the vehicle V i,j,k and the cluster head V i,j,1 of the vehicle cluster to which it belongs,The signal-to-interference-and-noise ratio between the vehicle V i,j,k and the cluster head V i,j,1 of the vehicle cluster to which the vehicle V i,j,k belongs;
Wherein, The formula is as follows:
In the method, in the process of the invention, For the transmit power of the cluster head V i,j,1,For the channel power gain between the vehicle V i,j,k and the cluster head V i,j,1 of the vehicle cluster to which it belongs, m is the mth vehicle in the vehicle cluster to which the vehicle V i,j,k belongs,To represent the coefficients of interference of communication between the cluster head V i,j,1 and the vehicle V i,j,k by other vehicles in the vehicle cluster to which the vehicle V i,j,k belongs,Indicating that there is an interference present and,Sigma 2 is the noise power, which indicates that no interference exists;
S42: when the vehicle V i,j,k acquires the cache content from the adjacent vehicle cluster in the communication coverage of the roadside unit RSU in the communication coverage of the target road section, communication connection is established among the vehicle V i,j,k, the cluster head V i,j,1 of the vehicle cluster to which the vehicle V i,j,k belongs and the cluster head of the adjacent vehicle cluster of the vehicle V i,j,k, the cache content is transmitted from the cluster head of the adjacent vehicle cluster of the vehicle V i,j,k to the vehicle V i,j,k through the cluster head V i,j,1 of the vehicle cluster to which the vehicle V i,j,k belongs, and communication between the cluster heads of the two vehicle clusters is not affected by cluster members;
The construction vehicle V i,j,k obtains a delay function T 2 of cache contents from cluster heads of adjacent vehicle clusters:
where o is the adjacent vehicle cluster of vehicle cluster j, V i,o,1 is the cluster head of vehicle cluster o, For the bandwidth between the cluster head V i,j,1 of the vehicle cluster j and the cluster head V i,o,1 of the vehicle cluster o,Is the signal-to-interference-and-noise ratio between the cluster head V i,j,1 and the cluster head V i,o,1;
Wherein, The formula is as follows:
In the method, in the process of the invention, For the transmit power of the cluster head V i,o,1,Channel power gain between cluster head V i,j,1 and cluster head V i,o,1;
S43: when the vehicle V i,j,k acquires the cache content from the roadside unit RSU for any vehicle V i,j,k in any one of the communication coverage areas of the roadside unit RSUs on the target road segment, communication connection is established between the vehicle V i,j,k, the cluster head V i,j,1 of the vehicle cluster to which the vehicle V i,j,k belongs, and the roadside unit RSUs, the cache content is transmitted from the roadside unit RSUs to the vehicle V i,j,k through the cluster head V i,j,1 of the vehicle cluster to which the vehicle V i,j,k belongs, and a time delay function T 3 for the vehicle V i,j,k to acquire the cache content from the roadside unit RSUs is constructed:
Wherein R i represents an i-th roadside unit RSU on the target road section, For the bandwidth between cluster head V i,j,1 and roadside unit RSUR i,Is the signal-to-interference-and-noise ratio between the cluster head V i,j,1 and the roadside unit RSUR i;
Wherein, The formula is as follows:
In the method, in the process of the invention, For the transmission power of the roadside unit RSUR i,For the channel gain between the cluster head V i,j,1 and the roadside unit RSUR i, neglecting the interference of other vehicles on the communication between the cluster head and the roadside unit RSU;
S44: aiming at a vehicle V i,j,k in a vehicle cluster in the communication coverage area of a roadside unit RSU on a target road section, when the vehicle V i,j,k acquires cache contents from an nonadjacent vehicle cluster in the communication coverage area of the roadside unit RSU in the communication range, the vehicle V i,j,k completes communication through the relay of the roadside unit RSU, and cluster heads of the nonadjacent vehicle cluster communicate, if the communication is directly carried out in a V2V mode, higher time delay and communication resource waste are generated, the communication link is unstable, and the relay communication of the roadside unit RSU is adopted, so that the time delay can be reduced, and the success rate of delivering the cache contents of the vehicle in the communication coverage area of the roadside unit RSU is improved;
constructing a delay function T 4 for a vehicle V i,j,k to acquire cache contents from non-adjacent vehicle clusters through a roadside unit RSU:
Where ρ 1 represents a vehicle cluster that is not adjacent to the vehicle cluster j, A cluster head representing a vehicle cluster ρ 1,Is a cluster headThe bandwidth between the road side unit RSUR i,Is a cluster headSignal-to-interference-and-noise ratio with roadside unit RSUR i;
S45: based on the cache cost C C of each cache content and the transmission cost C T of the cache content, constructing a cache content total cost function C as follows:
C＝CC+CT
wherein, the cache cost C C of the cache content is as follows:
CC＝CRSU·CSR+CV·CSV
Wherein, C RSU is the initial cache content capacity of the preset roadside unit RSU, C V is the initial cache content capacity of the preset vehicle, C SV is the cache content cost of the preset vehicle, C SR is the cache content cost of the preset roadside unit RSU, wherein, C RSU satisfies the condition C RSU≤SRSU,SRSU as the storage capacity of the preset roadside unit RSU, and C V≤SV,SV is the storage capacity of the preset vehicle;
Wherein, the transmission cost C T of the cache content is as follows:
CT＝CqR·CRR+CqV·CVV
Wherein, C RR is the transmission cost of transmitting a buffer content by the RSU, C VV is the transmission cost of transmitting a buffer content by the RSU, C VV≤CRR,CqR is the total number of buffer contents transmitted by the RSU, and C qV is the total number of buffer contents transmitted by the RSU.
S5, constructing a delay and cache content total cost acquisition minimization objective function and constraint conditions based on the delay function and the cache content total cost acquisition function.
The steps of minimizing the objective function and the constraint condition for the delay and obtaining the total cost of the cache content are as follows:
S51: in order to avoid the cache redundancy, the same cache content cannot be cached repeatedly, namely, each cache content can only be cached once in the caching process of all the roadside units (RSUs) and vehicles, and a cache placement matrix is constructed based on each cache content and the placement mode of the cache content The formula is as follows:
In the cache placement matrix Lines 1 to Q of (1) respectively represent 1 st to Q th cache contents, and cache placement matrixWherein the 1 st column represents a roadside unit (RSU), and the 2 nd to N C +1 st columns represent 1 st to N C th vehicle clusters, respectively; matrix placement for cacheEach node in (a)When the node is located, the cache content corresponding to the line of the node is stored in the cache position corresponding to the column of the node,When the cache content corresponding to the line where the node is located is not stored in the cache position corresponding to the column where the node is located;
s52: based on time delay function for obtaining cache content, total cost function for obtaining cache content and cache placement matrix The minimum objective function for constructing delay and obtaining the total cost of cache content is as follows:
Wherein, W T is a weight coefficient for time delay, T is a time delay function corresponding to a mode of acquiring cache content according to a vehicle, W C is a weight coefficient for cost, and W T+WC =1;
the constraint that the delay and the total cost of obtaining the cache contents minimize the objective function is as follows:
(1)
(2)
(3)
(4)
in the formula, x represents a cache placement matrix One of 1 st to N C +1 st columns, y represents a cache placement matrixOne of the 2 nd to the N C +1 th columns, S RSU is a preset roadside unit (RSU) storage capacity, S V is a preset vehicle storage capacity, the first two constraint conditions indicate that the cache content cannot be cached repeatedly, and the second two constraint conditions are cache capacity constraint conditions, and indicate that the cache content of each node cannot be larger than the own cache capacity.
S6, constructing a caching scheme sample, solving a delay and acquisition caching content total cost minimization objective function by adopting an ant colony algorithm, and obtaining the delay and acquisition caching content total cost corresponding to the caching scheme sample, and the pheromone, heuristic information and transfer probability corresponding to the caching scheme sample, wherein the specific method is as follows:
S61, respectively using buffer storage placement matrixes corresponding to different buffer storage placement modes Constructing a buffer placement scheme sample, wherein one buffer placement scheme sample corresponds to one ant in the ant colony algorithm, different buffer placement scheme samples participate in iteration in the ant colony algorithm, and the pheromone of each ant in the iteration is calculated, wherein the pheromone of the t iteration of the b-th ant is τ b (t), and the pheromone of the t+1st iteration is τ b (t+1) as follows:
τb(t+1)＝(1-ρ2)·τb(t)+χb
Wherein ρ 2 is a pheromone attenuation coefficient, 1- ρ 2 represents the volatilization condition of the pheromone after one iteration, χ b is the pheromone left by the cache placement scheme sample corresponding to the b-th ant, and χ b is as follows:
Wherein, T (b) is a time delay function of a buffer solution sample corresponding to the b-th ant, C (b) is a buffer content total cost function of a buffer placement solution sample corresponding to the b-th ant, the larger χ b is, the better the system performance under the solution is, the smaller the time delay obtained by the buffer placement solution sample and the total cost of obtaining the buffer content are, and the more pheromones are accumulated by the solution;
s62, based on an ant colony algorithm, heuristic information of each ant in iteration is calculated as follows:
Wherein α b is heuristic information of the b-th ant, a larger α b indicates that the path is more likely to become an optimal path, a larger α b in the embodiment of the present invention indicates that the cache placement scheme is more likely to become an optimal scheme, β (b) indicates uniformity of caching the cache content in the vehicle and the roadside unit RSU, and β (b) has the following formula:
Wherein, C RSU (b) is the initial cache content capacity of the preset roadside unit RSU of the cache scheme sample corresponding to the b-th ant, and C V (b) is the preset vehicle cache content cost of the cache scheme sample corresponding to the b-th ant;
s63, calculating the transition probability of each ant based on pheromone and heuristic information of each ant in iteration, wherein the transition probability is as follows:
Wherein P (b) is the transition probability of the b-th ant, u is the influence coefficient of the pheromone on the selected cache placement scheme, v is the influence coefficient of heuristic information on the selected cache placement scheme, For the pheromone of the b-th ant based on the influence coefficient u,For heuristic information of the b-th ant based on the influence coefficient v, c is another ant,Based on the pheromone of the c-th ant affecting the coefficient u,Is heuristic information of the c-th ant based on the influence coefficient v.
The embodiments of the present invention have been described in detail with reference to the drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present invention.
Claims (4)
1. A collaborative caching method based on vehicle clustering is characterized in that cache contents are stored in each roadside unit RSU on a target road section or cluster heads of each vehicle cluster in communication coverage of each roadside unit RSU, when a vehicle in a vehicle cluster requests the cache contents, the vehicle is firstly requested to the cluster head of the vehicle cluster to which the vehicle belongs, if the cluster head of the vehicle cluster to which the vehicle belongs does not have the requested contents, the vehicle sends out requests to cluster heads of other vehicle clusters in the communication coverage of the roadside unit RSU and the roadside unit RSU, and when the vehicle sends out requests to the cluster heads of the vehicle clusters not adjacent to the vehicle cluster to which the vehicle belongs, the roadside unit RSU is required to be used as a relay;
the method for collaborative caching based on vehicle clustering comprises the following steps of completing placement of cache content positions according to a preset period, enabling a vehicle to acquire cache content from a cluster head or a roadside unit (RSU) of a vehicle cluster, and minimizing time delay and cost in the process of acquiring the cache content;
S1, dividing vehicle clusters in the communication coverage area of each roadside unit RSU according to each roadside unit RSU on a target road section, wherein the communication coverage area of each roadside unit RSU at least comprises one vehicle cluster, and each vehicle cluster at least comprises one vehicle;
s2, initializing vehicle information: for each vehicle in each vehicle cluster on a target road section, taking other vehicles in a vehicle communication range as neighbor vehicles, and acquiring the number N of the neighbor vehicles, the average distance d between the vehicles and each neighbor vehicle and the sum v d of the speed differences between the vehicles and each neighbor vehicle;
S3, respectively calculating the weight of each vehicle in the vehicle cluster to which the vehicle belongs, if the weight of the vehicle is greater than the weight of each vehicle in the vehicle cluster to which the vehicle belongs, taking the vehicle as a cluster head of the vehicle cluster, otherwise, taking the vehicle as a cluster member of the vehicle cluster;
S4, constructing a delay function for acquiring the cache content and a total cost function for acquiring the cache content according to different methods for acquiring the cache content based on a method for acquiring the cache content by a vehicle from a cluster head of a vehicle cluster or a roadside unit (RSU) of a communication range to which the vehicle belongs;
in step S4, the steps of constructing a delay function for obtaining the cache content and obtaining a total cost function of the cache content are as follows:
s41: for any vehicle in any vehicle cluster in the communication coverage area of each roadside unit RSU on the target road section, constructing a delay function T 1 for the vehicle to acquire cache contents from a cluster head of the vehicle cluster to which the vehicle belongs:
Wherein V i,j,k is the kth vehicle in the jth vehicle cluster in the communication coverage of the ith roadside unit RSU on the target road section, V i,j,1 is the cluster head of the vehicle cluster to which the vehicle V i,j,k belongs, and i epsilon {1,2,3, …, N R},NR are the total number of the roadside units RSU on the target road section; j epsilon {1,2,3, …, N C},NC is the total number of vehicle clusters in the communication coverage of the i-th roadside unit RSU; k is {1,2,3, …, n }, n being the total number of vehicles in the jth vehicle cluster; q is the number of the cache content requested by the vehicle in the cache content set, Q is {1,2,3, …, Q }, Q is the total number of the cache content in the cache content set; s q is the ziff distribution parameter of the qth cache content in the cache content set, For the bandwidth between the vehicle V i,j,k and the cluster head V i,j,1 of the vehicle cluster to which it belongs,The signal-to-interference-and-noise ratio between the vehicle V i,j,k and the cluster head V i,j,1 of the vehicle cluster to which the vehicle V i,j,k belongs;
Wherein, The formula is as follows:
In the method, in the process of the invention, For the transmit power of the cluster head V i,j,1,For the channel power gain between the vehicle V i,j,k and the cluster head V i,j,1 of the vehicle cluster to which it belongs, m is the mth vehicle in the vehicle cluster to which the vehicle V i,j,k belongs,To represent the coefficients of interference of communication between the cluster head V i,j,1 and the vehicle V i,j,k by other vehicles in the vehicle cluster to which the vehicle V i,j,k belongs,Indicating that there is an interference present and,Sigma 2 is the noise power, which indicates that no interference exists;
S42: when the vehicle V i,j,k acquires the cache content from the adjacent vehicle cluster in the communication coverage of the roadside unit RSU of the communication range for any one vehicle V i,j,k in the communication coverage of the roadside unit RSU of the target road segment, communication connection is established among the vehicle V i,j,k, the cluster head V i,j,1 of the vehicle cluster to which the vehicle V i,j,k belongs, and the cluster head of the adjacent vehicle cluster of the vehicle V i,j,k, the cache content is transmitted from the cluster head of the adjacent vehicle cluster of the vehicle V i,j,k, through the cluster head V i,j,1 of the vehicle cluster to which the vehicle V i,j,k belongs, to the vehicle V i,j,k, and the time delay function T 2 of the vehicle V i,j,k acquiring the cache content from the cluster head of the adjacent vehicle cluster is constructed:
where o is the adjacent vehicle cluster of vehicle cluster j, V i,o,1 is the cluster head of vehicle cluster o, For the bandwidth between the cluster head V i,j,1 of the vehicle cluster j and the cluster head V i,o,1 of the vehicle cluster o,Is the signal-to-interference-and-noise ratio between the cluster head V i,j,1 and the cluster head V i,o,1;
Wherein, The formula is as follows:
In the method, in the process of the invention, For the transmit power of the cluster head V i,o,1,Channel power gain between cluster head V i,j,1 and cluster head V i,o,1;
S43: when the vehicle V i,j,k acquires the cache content from the roadside unit RSU for any vehicle V i,j,k in any one of the communication coverage areas of the roadside unit RSUs on the target road segment, communication connection is established between the vehicle V i,j,k, the cluster head V i,j,1 of the vehicle cluster to which the vehicle V i,j,k belongs, and the roadside unit RSUs, the cache content is transmitted from the roadside unit RSUs to the vehicle V i,j,k through the cluster head V i,j,1 of the vehicle cluster to which the vehicle V i,j,k belongs, and a time delay function T 3 for the vehicle V i,j,k to acquire the cache content from the roadside unit RSUs is constructed:
Wherein R i represents an i-th roadside unit RSU on the target road section, For the bandwidth between cluster head V i,j,1 and roadside unit RSUR i,Is the signal-to-interference-and-noise ratio between the cluster head V i,j,1 and the roadside unit RSUR i;
Wherein, The formula is as follows:
In the method, in the process of the invention, For the transmission power of the roadside unit RSUR i,Channel gain between cluster head V i,j,1 and roadside unit RSUR i;
S44: aiming at a vehicle V i,j,k in a vehicle cluster in the communication coverage area of a roadside unit RSU on a target road section, when the vehicle V i,j,k acquires cache contents from non-adjacent vehicle clusters in the communication coverage area of the roadside unit RSU in the communication range, the vehicle V i,j,k completes communication through the relay of the roadside unit RSU, and a delay function T 4 of acquiring the cache contents from the non-adjacent vehicle clusters through the roadside unit RSU is constructed by the vehicle V i,j,k:
Where ρ 1 represents a vehicle cluster that is not adjacent to the vehicle cluster j, A cluster head representing a vehicle cluster ρ 1,Is a cluster headThe bandwidth between the road side unit RSUR i,Is a cluster headSignal-to-interference-and-noise ratio with roadside unit RSUR i;
S45: based on the cache cost C C of each cache content and the transmission cost C T of the cache content, constructing a cache content total cost function C as follows:
C＝CC+CT
wherein, the cache cost C C of the cache content is as follows:
CC＝CRSU·CSR+CV·CSV
Wherein, C RSU is the initial cache content capacity of the RSU of the preset roadside unit, C V is the initial cache content capacity of the preset vehicle, C SV is the cache content cost of the preset vehicle, and C SR is the cache content cost of the RSU of the preset roadside unit;
Wherein, the transmission cost C T of the cache content is as follows:
CT＝CqR·CRR+CqV·CVV
Wherein, C RR is the transmission cost of a cache content transmitted by the RSU, C VV is the transmission cost of a cache content transmitted by the vehicle, C qR is the total number of cache contents transmitted by the RSU, and C qV is the total number of cache contents transmitted by the vehicle;
s5, constructing a delay and cache content total cost acquisition minimization objective function and constraint conditions based on the delay function and the cache content total cost acquisition function;
In step S5, the steps of minimizing the objective function and the constraint condition for the total cost of the cache content are as follows:
s51: respectively constructing a cache placement matrix based on each cache content and the placement mode of the cache content The formula is as follows:
In the cache placement matrix Lines 1 to Q of (1) respectively represent 1 st to Q th cache contents, and cache placement matrixWherein the 1 st column represents a roadside unit (RSU), and the 2 nd to N C +1 st columns represent 1 st to N C th vehicle clusters, respectively; matrix placement for cacheWhen a .... =1, it indicates that the cache content corresponding to the line where the node is located is stored in the cache position corresponding to the column where the node is located, and when a .... =0, it indicates that the cache content corresponding to the line where the node is located is not stored in the cache position corresponding to the column where the node is located;
s52: based on time delay function for obtaining cache content, total cost function for obtaining cache content and cache placement matrix The minimum objective function P 1 for constructing the delay and obtaining the total cost of the cache contents is as follows:
P1:
Wherein W T is a weight coefficient for time delay, T is a time delay function corresponding to a mode of acquiring cache contents according to a vehicle, and W C is a weight coefficient for cost;
the constraint that the delay and the total cost of obtaining the cache contents minimize the objective function is as follows:
(1) a....＝{0,1}
(2)
(3)
(4)
in the formula, x represents a cache placement matrix One of 1 st to N C +1 st columns, y represents a cache placement matrixOne of the 2 nd to N C +1 th columns, S RSU is a preset roadside unit (RSU) storage capacity, and S V is a preset vehicle storage capacity;
s6, constructing a caching scheme sample, solving a delay and cache content total cost obtaining minimization objective function by adopting an ant colony algorithm, and obtaining delay corresponding to the caching scheme sample, cache content total cost obtaining, pheromone, heuristic information and transition probability corresponding to the caching scheme sample;
the specific method of step S6 is as follows:
S61, respectively using buffer storage placement matrixes corresponding to different buffer storage placement modes Constructing a buffer placement scheme sample, wherein one buffer placement scheme sample corresponds to one ant in the ant colony algorithm, different buffer placement scheme samples participate in iteration in the ant colony algorithm, and the pheromone of each ant in the iteration is calculated, wherein the pheromone of the t iteration of the b-th ant is τ b (t), and the pheromone of the t+1st iteration is τ b (t+1) as follows:
τb(t+1)＝(1-ρ2)·τb(t)+Xb
Wherein ρ 2 is a pheromone attenuation coefficient, 1- ρ 2 represents the volatilization condition of the pheromone after one iteration, and X b is the pheromone left by the buffer storage scheme sample corresponding to the b-th ant, and χ b is as follows:
Wherein T (b) is a time delay function of a buffer solution sample corresponding to the b-th ant, and C (b) is a total cost function of buffer contents of the buffer solution sample corresponding to the b-th ant;
s62, based on an ant colony algorithm, heuristic information of each ant in iteration is calculated as follows:
wherein α b is heuristic information of the b-th ant, β (b) represents uniformity of caching content in the vehicle and the roadside unit RSU, and β (b) is as follows:
Wherein, C RSU (b) is the initial cache content capacity of the preset roadside unit RSU of the cache scheme sample corresponding to the b-th ant, and C V (b) is the preset vehicle cache content cost of the cache scheme sample corresponding to the b-th ant;
s63, calculating the transition probability of each ant based on pheromone and heuristic information of each ant in iteration, wherein the transition probability is as follows:
Wherein P (b) is the transition probability of the b-th ant, u is the influence coefficient of the pheromone on the selected cache placement scheme, v is the influence coefficient of heuristic information on the selected cache placement scheme, For the pheromone of the b-th ant based on the influence coefficient u,For heuristic information of the b-th ant based on the influence coefficient v, c is another ant,Based on the pheromone of the c-th ant affecting the coefficient u,Heuristic information of the c-th ant based on the influence coefficient v;
S7, taking the minimum time delay and the total cost of the obtained cache content as targets, obtaining the cache scheme sample which minimizes the time delay and the total cost of the obtained cache content through the participation iteration of each cache scheme sample, and completing the placement of the cache content position based on the cache scheme sample.
2. The vehicle clustering-based collaborative caching method according to claim 1, wherein in the step S2, for the kth vehicle in the vehicle cluster, denoted by V k, an average distance d between the target vehicle V k and each neighboring vehicle is as follows:
Where x 1 and x k represent the abscissa of vehicle V 1 and vehicle V k, respectively, and y 1 and y k represent the ordinate of vehicle V 1 and vehicle V k, respectively;
The sum V d of the speed differences between the vehicle V k and each neighboring vehicle is as follows:
Where V 1 and V k represent the speeds of vehicle V 1 and vehicle V k, respectively.
3. The collaborative caching method based on vehicle clustering as claimed in claim 2, wherein in the step S3, a weight calculation method of each vehicle in a vehicle cluster to which the vehicle V k belongs is as follows:
wherein, w 1、w2、w3 has the following relation:
w1+w2+w3＝1
Where w is the weight of the vehicle, w 1 is the weight factor of the number of neighboring vehicles, w 2 is the weight factor of the average distance between the vehicle V k and each neighboring vehicle, and w 3 is the weight factor of the sum of the speed differences between the vehicle V k and each neighboring vehicle.
4. The collaborative caching method based on vehicle clustering according to claim 3, wherein the step S7 is to construct a cache placement scheme in the next iteration based on the transition probability, update pheromone, heuristic information and transition probability, stop iteration when the iteration number reaches the preset maximum iteration number, record the time delay and the total cost of the requested content corresponding to the cache placement scheme as the cache placement scheme with the minimum time delay and the minimum total cost of the requested content corresponding to the last iteration, and finish the placement of the cache content position according to the time delay and the total cost of the requested content.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210161140.1A CN114666842B (en) | 2022-02-22 | Collaborative caching method based on vehicle clustering |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210161140.1A CN114666842B (en) | 2022-02-22 | Collaborative caching method based on vehicle clustering |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114666842A CN114666842A (en) | 2022-06-24 |
| CN114666842B true CN114666842B (en) | 2024-07-02 |
Family
ID=
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112104999A (en) * | 2020-08-03 | 2020-12-18 | 广东工业大学 | Multi-layer caching method in heterogeneous edge internet of vehicles |
| CN113132483A (en) * | 2021-04-20 | 2021-07-16 | 昆明理工大学 | Car networking accident video message distribution method based on V2X |
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112104999A (en) * | 2020-08-03 | 2020-12-18 | 广东工业大学 | Multi-layer caching method in heterogeneous edge internet of vehicles |
| CN113132483A (en) * | 2021-04-20 | 2021-07-16 | 昆明理工大学 | Car networking accident video message distribution method based on V2X |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111385734B (en) | Internet of vehicles content caching decision optimization method | |
| CN113094982B (en) | Internet of vehicles edge caching method based on multi-agent deep reinforcement learning | |
| CN110312231A (en) | Content caching decision and resource allocation joint optimization method based on mobile edge calculations in a kind of car networking | |
| CN114827198B (en) | Multi-layer center asynchronous federal learning method applied to Internet of vehicles | |
| CN113055488B (en) | Vehicle edge cooperation caching method and system for multilayer federal deep reinforcement learning | |
| CN114374741B (en) | Dynamic grouping internet of vehicles caching method based on reinforcement learning under MEC environment | |
| CN113905354B (en) | Vehicle-mounted network content transfer method and system based on regional content popularity | |
| CN114973673B (en) | Task unloading method combining NOMA and content cache in vehicle-road cooperative system | |
| CN112908011B (en) | Energy consumption-based unmanned HD Map data distribution method | |
| CN113543071A (en) | Heterogeneous node cooperative edge caching method in Internet of vehicles environment | |
| CN112565377A (en) | Content grading optimization caching method for user service experience in Internet of vehicles | |
| CN115297170A (en) | Cooperative edge caching method based on asynchronous federation and deep reinforcement learning | |
| CN114666843A (en) | Cooperative caching method in layered network architecture | |
| Facchina et al. | Speed based distributed congestion control scheme for vehicular networks | |
| CN114666842B (en) | Collaborative caching method based on vehicle clustering | |
| CN108882257B (en) | Adaptive chance retransmission method in vehicular ad hoc network based on collision probability | |
| CN114979145B (en) | Content distribution method integrating sensing, communication and caching in Internet of vehicles | |
| US20230156262A1 (en) | Content delivery method and system through in-vehicle nrtwork based on regional content popularity | |
| CN114666842A (en) | Cooperative caching method based on vehicle clustering | |
| CN114630299B (en) | Information age perceivable resource allocation method based on deep reinforcement learning | |
| CN116249162A (en) | Collaborative caching method based on deep reinforcement learning in vehicle-mounted edge network | |
| Lyu et al. | Service-driven resource management in vehicular networks based on deep reinforcement learning | |
| CN114916087A (en) | Dynamic spectrum access method based on India buffet process in VANET system | |
| US11985186B1 (en) | Method of drone-assisted caching in in-vehicle network based on geographic location | |
| CN114449477B (en) | Internet of vehicles content distribution method based on edge caching and immune cloning strategy |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant |