CN107889160B - Small cell network edge part caching method considering user time delay - Google Patents

Small cell network edge part caching method considering user time delay Download PDF

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CN107889160B
CN107889160B CN201711132758.0A CN201711132758A CN107889160B CN 107889160 B CN107889160 B CN 107889160B CN 201711132758 A CN201711132758 A CN 201711132758A CN 107889160 B CN107889160 B CN 107889160B
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small cell
base station
cached
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CN107889160A (en
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张鹤立
刘洪燕
李曦
纪红
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Beijing University of Posts and Telecommunications
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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W28/00Network traffic management; Network resource management
    • H04W28/02Traffic management, e.g. flow control or congestion control
    • H04W28/0278Traffic management, e.g. flow control or congestion control using buffer status reports
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L67/00Network arrangements or protocols for supporting network services or applications
    • H04L67/50Network services
    • H04L67/56Provisioning of proxy services
    • H04L67/568Storing data temporarily at an intermediate stage, e.g. caching
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/40Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
    • H04N21/43Processing of content or additional data, e.g. demultiplexing additional data from a digital video stream; Elementary client operations, e.g. monitoring of home network or synchronising decoder's clock; Client middleware
    • H04N21/433Content storage operation, e.g. storage operation in response to a pause request, caching operations
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W28/00Network traffic management; Network resource management
    • H04W28/02Traffic management, e.g. flow control or congestion control
    • H04W28/06Optimizing the usage of the radio link, e.g. header compression, information sizing, discarding information

Abstract

The invention discloses a small cell network edge part caching method considering user time delay, and belongs to the technical field of wireless communication. Firstly, rearranging a cache video file alternative set according to the heat degree, and obtaining a corresponding heat degree value and a corresponding video file size; then, calculating the maximum number K of the video files which can be completely cached; according to the maximum number K, iteration is carried out by utilizing the variance method between the maximum classes, and the number of the iteration is less than or equal to the caching threshold value ScThe video file is completely cached, and the video file is larger than a caching threshold value ScThe video file is partially cached; when a user initiates a content request to a small cell base station, if a video file is completely cached, the user acquires complete content from the small cell base station and ends; if the content is partially cached or not cached, the content is requested from a content server in the core network through a backhaul link. The invention can ensure the access delay of the user, improve the cache hit rate, improve the utilization rate of the cache space of the small base station and effectively relieve the bandwidth pressure of a return link.

Description

Small cell network edge part caching method considering user time delay
Technical Field
The invention relates to the technical field of wireless communication, in particular to a small cell network edge part caching method considering user time delay.
Background
According to the white paper prediction of Cisco, in 2019, mobile data flow accounts for about 75% of global data flow, most of the mobile data flow is borne by video flow, and with the global popularization of intelligent terminals and the continuous development of self-media in the global environment, the network video flow tends to increase exponentially. Today's macro cellular network capacity has not been able to expand further to meet the ever increasing traffic demands.
In order to solve the problem, a Small Cell (Small Cell) network is introduced, and under the coverage of a macro cellular network, the capacity of the system is greatly improved and the traffic demand on the network is relieved through the intensive deployment of Small Cell base stations. However, a weak small cell backhaul link weakens the advantage, so that edge caching becomes a research hotspot in recent years, and the edge caching can obtain a higher return by paying cheap storage resources. The edge cache enables a user to acquire a desired network resource nearby without passing through a weak backhaul link, so that on one hand, the request delay of the user is greatly reduced, and on the other hand, the transmission pressure of the backhaul link is relieved, and therefore, the service performance of the small cell system can be greatly improved by deploying a cache mechanism in the small cell base station in a mode of edge cache in the small cell system.
Since the storage capacity is still limited, each small cell base station node cannot cache all network videos, but only a very small part of the network videos can be cached, as can be seen from the twenty-eight law, 20% of video contents in the network bear 80% of network traffic, so 20% is the main considered caching object, but even then, the 20% of contents cannot be completely cached, so researchers begin to research a better caching configuration scheme to maximize the caching efficiency.
The existing edge caching scheme is divided into two categories according to cached nodes: one is a centralized cache and one is a distributed cache. The most advantage of the centralized cache is its simplicity, all nodes cache the same content, and the cache efficiency is low due to the limited cache capacity; the distributed cache has the advantages that the characteristic that a user is connected with a plurality of nodes is reasonably utilized, different nodes are deployed with different contents in a certain range, and therefore high cache efficiency is obtained. The caching mode according to each file can be divided into a complete cache and a partial cache, wherein the complete cache completely caches each file to a node, and the partial cache caches a part of each file to the node.
In the current research of wireless network edge caching, most scholars design edge caching schemes for the case that the size of each file is assumed to be equal, and most scholars adopt a complete caching mode, that is, each file cached is complete. In addition, researchers also study partial caching, namely only caching a part of each file at the edge, and acquiring the rest of each file from a network center, and the benefit of partial caching is obviously higher than that of complete caching. But still based on the conclusion that each file is of equal size and therefore does not take into account the fact that the files are of different sizes. In practice, the difference in file size affects the effectiveness of edge caching, whether full or partial caching.
In summary, in the prior art, on one hand, the existing edge cache research does not consider the situation of unequal file sizes, and on the other hand, the existing partial cache scheme does not provide the optimal cache percentage, so the benefit of the edge cache does not reach the optimal state. In the design scheme of the edge cache, the cache hit rate is not only dependent on the heat degree of each file, but also related to the size of each file, and the cache benefit is not only related to the cache hit rate, but also related to the burst amount of the backhaul link. One of the most important factors in the user experience is latency, and thus the design of the edge caching scheme cannot be decoupled from this factor.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a small cell network edge part caching method considering user time delay in order to maximize caching benefit in the limited edge caching space of a small cell network and according to the influence of different factors of file size on the caching benefit.
The method comprises the following specific steps:
step one, establishing a small cell network scene comprising a core network, a macro base station, a small cell base station and users covered around the small cell base station;
each small cell base station is used to deploy a content cache file.
Step two, setting the maximum capacity M of a cache region of a certain small cell base station and a cache video file alternative set of the small cell base station;
randomizing the sizes of all cached video files to obtain an alternative set of f1,f2,....fn};
Thirdly, rearranging the cache video file alternative selection set of the small base station from high to low according to the heat{fh1,fh2,....fhnCorresponding to a calorific value of { p }h1,ph2,....phnAnd the corresponding video file size is { S }h1,Sh2,....Shn};
Step four, aiming at the base station, on the premise of not exceeding the maximum capacity M of the cache region, calculating the maximum number K of video files which can be completely cached;
all the video files stored completely have the size of
Figure BDA0001469706230000021
Step five, under the condition of ensuring the time delay of the user, obtaining the optimal cache threshold S of the base station for each video file after the iteration times of the maximum inter-class variance method reach the maximum number Kc
The method comprises the following specific steps:
firstly, aiming at a video requested to be played by a user, calculating conditions which need to be met when the user plays the video without initial delay or pause delay;
the specific conditions are as follows:
Figure BDA0001469706230000022
R1for download rate from small base station to terminal equipment, MpThe content minimum value needs to be cached on the terminal equipment when the video is played; mpSatisfies Mp<min{ShiAnd Sc>Mp;ScA caching threshold for each video file; t is t0Maximum initial delay acceptable to the user; r2The download rate from the core network to the small base station; v is the playing speed of the video.
Then, calculating a buffer threshold value S according to the condition of satisfying the time delaycAnd obtaining a buffer threshold ScA number of results of (a);
the constraint is as follows:
Figure BDA0001469706230000031
finally, the maximum inter-class variance method is adopted to carry out cache threshold value ScIterating the results for K times to obtain the cache threshold S corresponding to the maximum inter-class variance valuecAs an optimal result;
Figure BDA0001469706230000032
the cached file satisfies S when partially cachedhi>ScThe number of files of (1) is m, Shi<ScThe number of files is n, and m + n is K;
step six, according to the optimal caching threshold ScCaching all cached video files sorted according to the heat degree, and caching the cached video files less than or equal to a caching threshold value ScThe video file is completely cached; for the value greater than the cache threshold ScThe video file of (2) is selected to have a length of ScThe front end part of the buffer memory;
the number of the completely cached video files is K.
Step seven, the user sends a content request to the small cell base station;
step eight, the small cell base station judges whether the request content is cached and is completely cached, if so, the user directly obtains the complete content from the small cell base station and ends; otherwise, entering the ninth step;
step nine, the small cell base station judges whether the request content is partially cached, if so, the step ten is carried out; otherwise, the request content is not cached, and the user requests the content from the content server in the core network through the backhaul link.
Step ten, the user acquires the cached part of the content from the small cell base station, and simultaneously acquires the rest content from the content provider through the wireless backhaul link.
The invention has the advantages that:
1) the invention discloses a small cell network edge part caching method considering user time delay, which can ensure the access time delay of users, improve the cache hit rate and improve the utilization rate of the cache space of a small base station.
2) The small cell network edge part caching method considering the user time delay can effectively relieve the bandwidth pressure of a backhaul link.
Drawings
Figure 1 is a schematic diagram of a small cell network scenario established by the present invention;
fig. 2 is a flowchart of a small cell network edge portion caching method considering user delay according to the present invention;
FIG. 3 is a diagram illustrating caching of a cached video file according to an optimal caching threshold in accordance with the present invention;
FIG. 4 is a schematic diagram of a full cache and a partial cache of video files in forward, reverse, and random distribution;
FIG. 5 is a graph comparing the caching threshold of video files under three distributions with the number of cached files and the request hit rate, respectively;
FIG. 6 is a graph showing the effect of the buffer capacity and the average delay of the video files in ascending distribution when the complete buffer is compared with the optimal threshold buffer;
FIG. 7 is a graph showing the effect of the average delay on the buffer capacity of a video file in descending order distribution when the complete buffer is compared with the optimal threshold buffer;
fig. 8 is a graph of the effect of the buffer capacity and the average delay of randomly distributed video files in comparison between the full buffer and the optimal threshold buffer.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples.
According to the invention, under the model of a small cell network system, the traditional process of equally processing the sizes of all files to be cached is abandoned, the sizes of the files are randomized, the cache file alternative set of a small cell base station is determined according to the heat of the video files, and the different characteristics of the sizes of the files and the time delay sensitivity of a user to the video files have important influence on the caching benefit; the simulation finds that the random distribution of the sizes of the files causes great difference in the occupied cache spaces of the files with different heat degrees, and in order to ensure the maximization of the cache benefit and obtain the maximum cache benefit by the minimum cache space, the maximum inter-class variance method in the image field is introduced to solve the optimal cache threshold of each small cell base station; by adopting a new edge cache mode, namely, partial caching is carried out on the large file according to the optimal cache threshold value, and the small file is completely cached; the simulation verifies that the content part caching scheme based on the optimal threshold value has higher caching benefit than the complete caching.
As shown in fig. 2, the specific steps are as follows:
step one, establishing a small cell network scene comprising a core network, a macro base station, a small cell base station and users covered around the small cell base station;
the simulation scenario is established as shown in fig. 1, and each small cell base station has the capability of edge caching and is used for deploying a content cache file.
Step two, setting the maximum capacity M of a cache region of a certain small cell base station and a cache video file alternative set of the small cell base station;
randomizing the sizes of all cached video files in the network center to obtain an alternative selection set of F ═ F1,f2,....fn};M<F。
Thirdly, rearranging the cache video file alternative set of the small base station into { f } according to the heat from high to lowh1,fh2,....fhnCorresponding to a calorific value of { p }h1,ph2,....phnAnd the corresponding video file size is { S }h1,Sh2,....Shn};
Aiming at the fact that video heat distribution of a base station user obeys the twenty-eight law, 10% of hot videos account for 80% of video playing amount, and 90% of video contents only account for 20% of playing amount, therefore, the 10% of hot videos are objects cached by an edge base station, but M is still less than 10% F, the prior art obtains the conclusion that distributed caching is better than centralized caching, and therefore, in order to achieve better network benefits, the distributed base station caching in a macro cell range is adopted to be a more effective mode.
But to emphasize each video file size pairThe impact of cache hit rate and simplified model, using a centralized caching scheme, assuming a candidate set of cached video files { f }1,f2,....,fj,...,fnSatisfy:
Figure BDA0001469706230000051
wherein SjFor caching video files fjIs of a size of
Figure BDA0001469706230000052
There must be 0< lambda <1 such that
Figure BDA0001469706230000053
Cached video File alternate set { f1,f2,....,fj,...,fnThe file heat in the file is more than 80%, and the file is rearranged into { f ] according to the heat from high to lowh1,fh2,....fhnCorresponding heat magnitude of { p }h1,ph2,....phnAnd the corresponding video file size is { S }h1,Sh2,....Shn};
Setting xhjE {0,1} represents file fhjIf the cache is cached in the small cell base station cache, the following conditions are required to be met:
Figure BDA0001469706230000054
the cache hit rate at this time is expressed as:
Figure BDA0001469706230000055
it can be known that the cache hit rate is higher when the stored video files are more hot and the number of stored video files is more.
Step four, aiming at the base station, on the premise of not exceeding the maximum capacity M of the cache region, calculating the maximum number K of video files which can be completely cached;
in order to achieve higher cache hit rate, the invention completely caches the high-heat smaller video file, and only caches one part of the beginning of the file for the lower-heat larger video file, and the rest parts are obtained from a core network, and the better user experience can be ensured only by caching the whole files and the part of the files; but the method is realized on the premise of ensuring the quality of user experience:
Figure BDA0001469706230000056
Figure BDA0001469706230000061
all the video files stored completely have the size of
Figure BDA0001469706230000062
The maximum value K corresponds to a heat value of phKSatisfy phK>phn
Step five, under the condition of ensuring the time delay of the user, obtaining the optimal cache threshold S of the base station for each video file after the iteration times of the maximum inter-class variance method reach the maximum number Kc
To increase the cache hit rate, it is necessary to balance the sizes of the request hit rate and the byte hit rate, which may result in a decrease in the byte hit rate when the request hit rate is high. So that the threshold S is cachedcThe setting of (2) is crucial, and the problem of request delay needs to be considered.
The time delay is divided into two parts, namely an initial time delay before the requested video playing, and a pause time delay caused by network congestion and the like in the video playing process.
The method comprises the following specific steps:
firstly, aiming at a video requested to be played by a user, calculating conditions which need to be met when the user plays the video without initial delay or pause delay;
when the front-end part content of the hot video file is cached in the small cell base station, the initial time delay is mainly determined by the size of the part of the file cached in the base station, and the download rate from the small base station to the terminal equipment is set as R1The download rate from the core network to the small base station is R2Suppose that a cache M is required on the terminal devicepThe video can only start playing when the content size of (1) is small, and at this time, an inequality M existsp<min{ShiAnd Sc>MpLet the maximum initial delay accepted by the user be t0The conditions to be satisfied are:
Figure BDA0001469706230000063
for a file completely cached in the base station, it is assumed that the playing speed of the video is less than the downloading speed R1The video file completely cached in the base station will not have a pause delay in the playing process of the user.
And for a size Shi(Shi>Sc) In the small cell, only the front S is bufferedcFor long content, the following condition should be satisfied when the user plays the content with initial delay and without pause delay
Figure BDA0001469706230000064
V is the playing speed of the video.
Then, calculating a buffer threshold value S according to the condition of satisfying the time delaycAnd obtaining a buffer threshold ScA number of results of (a);
to ensure the quality of experience for the user, the constraint is as follows:
Figure BDA0001469706230000071
finally, iteration is carried out for K times by adopting a maximum inter-class variance method to obtainTaking the maximum buffer threshold S corresponding to the inter-class variance valuecAs an optimal result;
Figure BDA0001469706230000072
suppose that the cached file satisfies S when partially cachedhi>ScThe number of files of (1) is m, Shi<ScThe number of files is n, and m + n is K;
selecting the average value of K file sizes as an initial cache threshold ScPerforming loop iteration, and calculating S with the maximum value of the formulacA value; further calculating according to the size of the obtained optimal cache threshold and the cache capacity of the small base station: setting an optimal buffer threshold ScNumber of files N that can be cached later2
Step six, according to the optimal caching threshold ScDesigning a content part caching method of the small cell base station;
under the condition of limited cache capacity, the complete cache of the large file video occupies a larger storage space, so that the utilization efficiency of the storage space is greatly unfavorable. For these oversized video files, complete caching is not necessary, on one hand, most users can adopt a film watching mode of playing after offline caching, and at the moment, the requirements on real-time transmission delay are lower; on the other hand, the playing speed of the video is lower than the downlink transmission rate of the small cell base station, and the time delay requirement of the user can be ensured only by caching a part of the video in the edge network; moreover, for a smaller video file, the real-time requirement of a user is relatively high; therefore, a cache threshold is introduced to perform partial caching, when the size of the file is smaller than the cache threshold, complete caching is performed, and when the size of the file is larger than the cache threshold, only the part of the file with the front-segment content size as the threshold is cached, as shown in fig. 3, the shaded part is the cache part. Setting the caching threshold value helps to cache more smaller and more popular video files, so that better caching benefit is obtained.
The method specifically comprises the following steps:
all cached video files in the alternative setCaching from high to low in heat, and when the size of a certain video file is less than or equal to a caching threshold ScWhen the video file is cached, the video file is completely cached; otherwise, selecting the front end part length of the video file as the optimal caching threshold ScCaching; the number of the video files which can be completely cached is K.
Step seven, the user initiates a content request to the small cell base station, and the request process assumes that the content request complies with Poisson distribution;
step eight, the small cell base station judges whether the request content is cached and is completely cached, if so, the user directly obtains the complete content from the small cell base station and ends; otherwise, entering the ninth step;
each small cell base station stores the local hotspot video into a small cell Cache of a local area, when a small cell user requests content, if the small cell user caches corresponding content, the small cell base station directly provides service for the user, and if the small cell user does not have the corresponding content, the small cell base station obtains the content from a content server of a network center through a core network linked by a return link from the macro base station.
Step nine, the small cell base station judges whether the request content is partially cached, if so, the step ten is carried out; otherwise, the request content is not cached, and the user requests the content from the content server in the core network through the backhaul link.
Step ten, the user acquires the cached part of the content from the small cell base station, and simultaneously acquires the rest content from the content provider through the wireless backhaul link.
And finally, counting the cache hit times R of the user, the total request times A and the cache hit rate.
The invention has obvious influence on the benefit of edge cache by different video file size distribution, distinguishes the size of the video file by setting the cache threshold, introduces the maximum inter-class variance method into the edge cache to solve the optimal cache threshold in partial cache on the premise of ensuring the user delay tolerance, calculates the minimum energy consumption value of the corresponding system by jointly adjusting the cache strategy of the content and the access network selection scheme of the user, and obtains the optimal cache benefit.
In order to prove that different file sizes have a large influence on the caching benefit, the invention considers that MATLAB simulation is carried out on different file size distributions when the heat distribution of a cached video file alternative set is determined, as shown in FIG. 4, the assumption is made that the heat of a video file is uniformly distributed, the file distribution with higher heat and higher file size is in a reverse order distribution, the file distribution with higher heat and lower file size is in a positive order distribution, the meaning of a caching threshold value is that the file only caches the front-section content smaller than or equal to the caching threshold value, the left side in the figure represents the state during complete caching, the right side represents the partial caching state with the fixed threshold value of 500 under the same file size distribution as the left side, the abscissa represents the files arranged according to the heat, and the ordinate is the number of bytes of the file. It is known from the figure that the distribution of file sizes has a significant impact on caching efficiency, and the impact on the complete caching is greater than the impact on the partial caching. And the effect of partial cache is more stable than that of complete cache, so the adoption of the partial cache mode is more meaningful, and the performance of cache cannot ignore the factor of file size.
Setting a simulation scene of a hot spot video content part placement scheme as a common simulation network configuration of a small cell network, assuming that the cache capacity M is fixed to 20000M, 2000 cache candidate files are provided, the size of each file is a random value between 50M and 1500M, and the heat degree is discrete twenty-eight distribution; when the caching threshold is 500M, 1000 files with different sizes are randomly generated to serve as an alternative set of caching.
The content placement scheme simulation parameters are shown in table 1:
TABLE 1
Parameter(s) Value of
Small base station downlink rate 1.024(M/S)
Backhaul link downlink rate 2.2(M/S)
Playback rate 0.72(M/S)
As shown in fig. 5, the lower the cache threshold, the higher the request hit rate of the cache, but the request hit rate is not the only factor determining the network performance, and it is also necessary to consider the byte hit rate, the user delay, and the backhaul link occupation. When the cache threshold value is too low, although the request hit rate is high, the byte hit rate is reduced, so that not only is the cache benefit reduced, but also the bandwidth crisis of the backhaul link cannot be effectively alleviated. The size of the caching threshold has a significant impact on the caching efficiency.
The average delay effect graphs under different small base station buffer space capacities are shown in fig. 6, fig. 7 and fig. 8, the average delay of the user for acquiring the video resource is reduced along with the increase of the buffer capacity, and the comparison in the graphs shows that when the partial buffer method based on the optimal buffer threshold is adopted, the average delay of all the accesses of the user is lower than the average delay generated in the complete buffer method, so that the delay requirement of the user access can be ensured by adopting the partial buffer method based on the optimal buffer threshold; but also can improve the hit rate of the cache.

Claims (2)

1. A small cell network edge part caching method considering user time delay is characterized by comprising the following specific steps:
step one, establishing a small cell network scene comprising a core network, a macro base station, a small cell base station and users covered around the small cell base station;
step two, setting the maximum capacity M of a cache area of a small cell base station and a cache video file alternative set of the small cell base station aiming at a certain small cell base station;
randomizing the sizes of all cached video files to obtain an alternative set of f1,f2,....fn};
Thirdly, rearranging the cache video file alternative set of the small cell base station into { f according to the heat from high to lowh1,fh2,....fhnCorresponding to a calorific value of { p }h1,ph2,....phnAnd the corresponding video file size is { S }h1,Sh2,....Shn};
Step four, aiming at the small cell base station, on the premise of not exceeding the maximum capacity M of the buffer area, calculating the maximum number K of video files which can be completely buffered;
all the video files stored completely have the size of
Figure FDA0002252485260000011
Step five, under the condition of ensuring the user time delay, obtaining the optimal cache threshold value S of the small cell base station for each video file after the iteration times of the maximum inter-class variance method reach the maximum number Kc
The method comprises the following specific steps:
firstly, aiming at a video requested to be played by a user, calculating conditions which need to be met when the user plays the video without initial delay or pause delay;
the specific conditions are as follows:
Figure FDA0002252485260000012
R1for small cell base station to terminal equipment download rate, MpThe content minimum value needs to be cached on the terminal equipment when the video is played; mpSatisfies Mp<min{ShiAnd Sc>Mp;ScA caching threshold for each video file; t is t0Maximum initial delay acceptable to the user; r2The download rate from the core network to the small cell base station; v is the playing speed of the video;
then, calculating a buffer threshold value S according to the condition of satisfying the time delaycAnd obtaining a buffer threshold ScA number of results of (a);
the constraint is as follows:
Figure FDA0002252485260000013
finally, the maximum inter-class variance method is adopted to carry out cache threshold value ScIterating the results for K times to obtain the cache threshold S corresponding to the maximum inter-class variance valuecAs an optimal result;
Figure FDA0002252485260000021
the cached file satisfies S when partially cachedhi>ScThe number of files of (1) is m, Shi<ScThe number of files is n, and m + n is K;
step six, according to the optimal caching threshold ScCaching all cached video files sorted according to the heat degree, and caching the cached video files less than or equal to a caching threshold value ScThe video file is completely cached; for the value greater than the cache threshold ScThe video file of (2) is selected to have a length of ScThe front end part of the buffer memory;
k video files are completely cached;
step seven, the user sends a content request to the small cell base station;
step eight, the small cell base station judges whether the request content is cached and is completely cached, if so, the user directly obtains the complete content from the small cell base station and ends; otherwise, entering the ninth step;
step nine, the small cell base station judges whether the request content is partially cached, if so, the step ten is carried out; otherwise, the request content is not cached, and the user requests the content from a content server in the core network through a backhaul link;
step ten, the user acquires the cached part of the content from the small cell base station, and simultaneously acquires the rest content from the content provider through the wireless backhaul link.
2. The small cell network edge part caching method considering the user delay as claimed in claim 1, wherein in the fifth step, the delay is divided into two parts, one is an initial delay before the requested video playing, and the other is a pause delay caused by network congestion and the like in the video playing process.
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CN109218747B (en) * 2018-09-21 2020-05-26 北京邮电大学 Video service classification caching method based on user mobility in super-dense heterogeneous network
CN110417847B (en) * 2019-01-09 2020-09-01 北京邮电大学 Method and device for user access and content caching in unmanned aerial vehicle communication network
CN109889578B (en) * 2019-01-23 2021-03-02 中南大学 Transmission method and system for cloud-edge cooperative processing
CN110213627B (en) * 2019-04-23 2020-09-01 武汉理工大学 Streaming media cache allocation method based on multi-cell user mobility
CN110049507B (en) * 2019-05-05 2021-07-20 南京工程学院 Halter strap theory-based optimal buffer resource allocation method in wireless content distribution network
CN110177310A (en) * 2019-06-28 2019-08-27 三星电子(中国)研发中心 A kind of content distribution system and method
CN113497976A (en) * 2020-03-19 2021-10-12 华为技术有限公司 Multimedia data downloading method and electronic equipment
CN111465057B (en) * 2020-03-30 2021-06-04 北京邮电大学 Edge caching method and device based on reinforcement learning and electronic equipment
CN113301145B (en) * 2020-05-21 2022-07-08 北京航空航天大学 Mobile edge cache placement method adopting request rate and dynamic property of information source issued content
CN111752905B (en) * 2020-07-01 2024-04-09 浪潮云信息技术股份公司 Large file distributed cache system based on object storage
CN112839082B (en) * 2020-12-31 2023-04-07 西安电子科技大学 Heterogeneous edge cache allocation method, system, medium and application
CN112954383B (en) * 2021-03-02 2023-05-16 山东省计算中心(国家超级计算济南中心) Video on demand method, video on demand proxy server, base station and storage medium
CN114630183B (en) * 2022-03-17 2024-03-26 东南大学 Edge equipment caching method and evaluation method based on scalable coding

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001020910A1 (en) * 1999-09-14 2001-03-22 Streaming21, Inc. Method and apparatus for streaming data
CN1610403A (en) * 2004-11-16 2005-04-27 南京大学 Method for realizing video requesting system based on protocol buffer storage
CN103312776A (en) * 2013-05-08 2013-09-18 青岛海信传媒网络技术有限公司 Method and device for caching contents of videos by edge node server
CN104641655A (en) * 2013-04-07 2015-05-20 华为技术有限公司 Terminal cache method, terminal and server
CN104967861A (en) * 2015-05-27 2015-10-07 上海美琦浦悦通讯科技有限公司 CDN video buffer system and method

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060104600A1 (en) * 2004-11-12 2006-05-18 Sfx Entertainment, Inc. Live concert/event video system and method
CN101488967B (en) * 2009-01-14 2015-05-13 深圳市同洲电子股份有限公司 Video transmission method, embedded monitoring terminal and monitoring platform server
CN102075562B (en) * 2010-12-03 2014-08-20 华为技术有限公司 Cooperative caching method and device
US9247020B2 (en) * 2012-08-07 2016-01-26 Google Inc. Media content receiving device and distribution of media content utilizing social networks and social circles
CN103974097B (en) * 2014-05-22 2017-03-01 南京大学镇江高新技术研究院 Personalized user original video forecasting method based on popularity and social networkies and system
CN106686399B (en) * 2016-12-22 2019-07-02 陕西尚品信息科技有限公司 It is a kind of based on joint cache structure network in video cache method

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001020910A1 (en) * 1999-09-14 2001-03-22 Streaming21, Inc. Method and apparatus for streaming data
CN1610403A (en) * 2004-11-16 2005-04-27 南京大学 Method for realizing video requesting system based on protocol buffer storage
CN104641655A (en) * 2013-04-07 2015-05-20 华为技术有限公司 Terminal cache method, terminal and server
CN103312776A (en) * 2013-05-08 2013-09-18 青岛海信传媒网络技术有限公司 Method and device for caching contents of videos by edge node server
CN104967861A (en) * 2015-05-27 2015-10-07 上海美琦浦悦通讯科技有限公司 CDN video buffer system and method

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