JP3590376B2 - IP streaming system, policy server, and IP streaming distribution method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an IP streaming system and a policy for providing a communication service using IP streaming on a cable Internet.Server and IPRelated to streaming distribution methods.
[0002]
[Prior art]
2. Description of the Related Art In recent years, with the development of an infrastructure for two-way communication in CATV, data communication services such as video and music have been provided using the cable Internet.
[0003]
Such a data communication service is a best-effort service in which the line conditions vary depending on the usage status of the user due to the characteristics of the Internet.
[0004]
For example, when a data communication service provider intends to provide a service with a maximum data transmission rate of 1.5 Mbps per user in the down direction, a CMTS (Cable Modem Termination System; Cable Modem) called a cable router is provided for each user. Terminating device) to measure traffic per unit time in the downlink direction, and when the average value of a certain time exceeds 1.5 Mbps, take a method such as suspending the traffic in the downlink direction, and take a method such as a data communication service. Is provided.
[0005]
[Problems to be solved by the invention]
However, in the data communication services described above, multimedia contents such as video are transmitted over the Internet, and even in a broadcasting system using IP streaming that can be reproduced in real time, the multimedia contents must be reliably delivered. Is difficult.
[0006]
In the present invention, IP streaming refers to all techniques for distributing video and audio contents as IP packets using the Internet Protocol and reproducing the contents on the user side. The user receives the IP packets in a memory. In the narrow sense, and pseudo IP streaming, in which the user temporarily stores some or all of the contents in an HDD or the like and starts reproduction.
[0007]
The present invention has been made in view of the above circumstances, andfromIn response to a content viewing request, check the usage status of network resources, make effective use of network resources while ensuring QoS (Quality of Service: service quality), and distribute IP viewing systems and policies to distribute viewing request content.Server and IPAn object is to provide a streaming distribution method.
[0008]
[Means for Solving the Problems]
(1) In order to solve the above problems, from each user terminalSent via CMTS and networkFor content viewing requestsBased on the distribution serverContent requested for viewingTo the user terminalIP streaming system for distributionAt,
Prior to distributing the requested content, the distribution server for sending an inquiry as to whether QoS for distributing the content can be secured;
A resource management storage unit for storing time information related to the status of resources existing on the network path to each of the user terminals and resource use, and storing time information related to the use status and band use of the frequency band of the entire system; A frequency management storage unit to perform, and in response to an inquiry about securing of QoS including the request source information and the required band information from the distribution server under a content viewing request from the user terminal, refer to the resource management storage unit. A first judging means for judging whether or not there is a resource for securing the QoS regarding the viewing request content; and, when receiving an inquiry about the QoS securing including the request source information and the necessary band information from the distribution server, With reference to the storage means, in the cable to which the user terminal which has requested viewing is connected Second determining means for determining whether or not a wavenumber band is available, and resource utilization status of a network relay-related device including the CMTS present on a network path for distributing the content obtained from the first and second determining means And notifying the distribution server of whether or not QoS can be secured based on the usage status of the frequency band of the cable to which the user terminal is connected, and when QoS is not secured, relates to the resource use and the band use. Means for notifying the distribution server of a distributable time from time informationAnd a policy server withEquipped1 is a configuration of an IP streaming system.
[0009]
With the above configuration, the present invention notifies the distribution server when the navigation server receives the viewing request content from the user terminal based on the request source information. The distribution server reads the required bandwidth information of the content from the distribution information database based on the request source information and the viewing request content, and inquires, together with the request source information, whether the QoS of the content to be distributed can be secured to the policy server. I do. Here, the policy server determines the usage status of the resources of the network relay related device including the CMTS existing on the network route for distributing the content and the usage status of the frequency band of the cable to which the user terminal is connected. For realization, the use state of the resources and the state of the frequency band are determined. If both are in an appropriate state, it is determined that the QoS can be secured, and that the distribution server can distribute the content requested to be viewed. Since the notification is made, it is possible to effectively utilize the network resources while securing the QOS and distribute the viewing request content.
[0010]
It is also possible to provide each CMTS with a processing function for judging a resource use state and a frequency band state for realizing QoS.
[0011]
(2) In addition, the policy server according to the present invention may be configured such that resources existing on a network route to each user terminalThe time information related to the status and resource usage ofResource management storage means and frequency band of the entire systemStores time information related to usage status and bandwidth usageUpon receiving request source information and required band information from the outside based on a content viewing request from a user terminal, the frequency management storage unit refers to the resource management storage unit to secure QoS regarding the viewing request content. Upon receiving the request source information and the required band information from the outside, the first determining means for determining the presence or absence of the resource is referred to the frequency management storage means, and the user terminal that has requested viewing is connected.cableDetermining means for determining whether or not there is a free frequency band in the systemAnd the use status of the resources of the network relay-related device existing on the network route for distributing the content obtained from the first and second determination means and the use status of the frequency band of the cable to which the user terminal is connected Means for determining whether or not to secure QoS based on the information, and calculating a possible delivery time from time information relating to the resource use and the band use when QoS is not secured.Configuration.
[0012]
According to the present invention, when the policy server receives request source information and required band information from the outside such as a distribution server, the policy server refers to the resource management storage means and secures the QoS for the viewing request content. The presence / absence of resources is determined, and the frequency management storage unit is referred to determine whether or not a frequency band is vacant in a line connected to the user terminal that has requested viewing, so that the delivery server is notified that QoS can be secured. be able to.
[0014]
Further, the policy server is provided with a resource management storage unit and a frequency management storage unit, and it is determined whether there is a resource for securing QoS for the viewing request content and whether there is a free frequency band in a cable to which the user terminal is connected. Even if the resource management storage means and the frequency management storage means are provided in the device, for example, the CMTS, and the presence / absence of resources for securing the QoS regarding the viewing request content and the availability of the frequency band in the line connected to the user terminal are determined, It is possible to achieve the same operation and effect as the policy server that performs the operation.
[0015]
(3)The IP streaming distribution method according to the present invention comprises:In an IP streaming system in which a plurality of CMTSs accommodating cables to which a plurality of user terminals for requesting content viewing are connected and a head-end system for performing streaming distribution of the viewing request content are connected to a network, When a menu screen request is received from the terminal based on the request source information, a menu screen is transmitted to the user terminal, and a content request receiving step of receiving the viewing request content from the user terminal, and receiving the viewing request content by this step And an inquiry step of reading out pre-stored distribution request contents, band information necessary for distribution of the contents, distribution necessary time information and the like, and inquiring of a policy server accommodated in the head-end system whether QoS can be ensured. If an inquiry is received by the step, the resource the Policy Server in the network route to the requesting user terminal stored in the resource management storage meansInformation and time information related to resource usageAnd when the inquiry is received in the resource securing determination step of determining whether there is a resource for securing the QoS regarding the viewing request content and the inquiry step, the frequency band of the entire system isStores usage information and time information related to bandwidth usageThe user terminal is connected by referring to the frequency management storagecableA band securing determination step of determining whether or not a frequency band is vacant inSaidBy each judgment stepQoSWhen it is determined that the content can be secured, the head end system distributes the viewing request content to the requesting user terminal;Obtaining a delivery available time from time information related to the resource use and the band use when it is determined that the QoS is not secured in each of the determination steps;HaveWayIt is.
[0016]
Even in such a streaming distribution method, when a viewing request is received in the content request receiving step, the bandwidth information and the required distribution time information necessary for the distribution of the content stored in advance in the inquiry step are read out and transmitted to the policy server. The network including the CMTS in the network path for distributing content by referring to the resource information existing in the network path to the requesting user terminal stored in the resource management storage means because the policy server inquires whether the QoS can be secured. Since the usage status of the resources of the relay-related device and the usage status of the frequency band of the cable to which the user terminal is connected are determined, it is possible to effectively utilize the network resources while distributing the QoS and distribute the viewing request content. It becomes.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, prior to describing the embodiments of the present invention, for example, a broadcast system in the United States will be described.
[0018]
(1) The current state of the US broadcasting system.
[0019]
In a U.S. broadcasting system that broadcasts analog terrestrial waves on a cable, a frequency range of 50 MHz to 450 MHz is used in a frequency band available for RF (Radio Frequency). In this case, 6 MHz per channel is used. Degree of bandwidth is allocated.
[0020]
On the other hand, when performing data communication using the cable Internet, a band other than 450 MHz, for example, a frequency band of 500 MHz to 600 MHz is used. That is, when performing data communication, QAM (Quadrature Amplitude Modulation) modulation, which is digital modulation in a 6 MHz band, is used. In addition, the inside of an IP streaming compatible device such as a CMTS or IPB (set top box for IP streaming) is used. Are tuned for each 6 MHz band described above. The QAM system is a system that can carry a large amount of data within a narrow bandwidth by simultaneously modulating two parameters of amplitude, phase, and frequency, which are parameters of a sine carrier wave. Incidentally, the QAM modulation mainly used in the cable Internet includes the 64QAM system and the 256QAM system. For example, in the case of the 64QAM system, a transmission rate of about 27 Mbps can be obtained. Currently, a data communication service is provided in such a manner that many users share a transmission bandwidth of 27 Mbps.
[0021]
(2) Configuration of IP streaming system according to the present invention.
[0022]
FIG. 1 is a configuration diagram showing one embodiment of an IP streaming system according to the present invention.
[0023]
This IP streaming system includes a head-end system 10 that stores various types of multimedia contents and executes a distribution process in response to a viewing request from a user, a network 20 having a ring-shaped connection configuration, and a plurality of distribution systems. A HUB 30 is provided, and a user terminal 52 is connected via an IPB 51 to an RF cable 40 accommodated in each of the distribution HUBs 30. In the present invention, when it is called a user terminal, a combination of the IPB 51 and the user terminal 52 is targeted.
[0024]
In addition, since the distance between the distribution HUB 30 and the IPB 51 of the user terminal 52 is limited only by the RF cable 40, an electric-optical converter, an HFC (HFC) A Hybrid Fiber / Coax network, an optical-electrical converter, or the like is used, but is omitted here because it has little relevance to the gist of the present invention.
[0025]
The head-end system 10 includes a navigation server 11, a distribution server 12, a policy server 13, and a router 14 that can provide QoS.
[0026]
When the number of the CMTSs 31 is one, the head end system including the CMTSs 31 may be called.
[0027]
The navigation server 11 allows a user to view the menu while cooperating between an EPG (Electronic Program Guide), a navigation client software, and the like, which can easily browse menus owned by the server 11 itself. It has a role of receiving the type of content to be transmitted and notifying the distribution server 12.
[0028]
The distribution server 12 has a large-capacity distribution information database 15 that stores, in addition to various types of multimedia contents, band information necessary for distribution of each content, required distribution time information, and other information required for distribution. While managing the distribution information including the multimedia contents stored in the storage 15, when receiving the distribution notification from the navigation server 11, an inquiry is made to the policy server 13 as to whether QoS for distributing the contents can be secured. However, when QOS can be secured, it has a function of delivering desired content to the user.
[0029]
The policy server 13 has a resource management database 16 and a frequency management database 17, and upon receiving an inquiry about QoS reservation based on request source information such as an IP address and required band information from the distribution server 12, the policy server 13 A network including a CMTS 31 based on data stored in a resource management database 16 that manages resources for realizing QoS of a network relay-related device including a CMTS and a frequency management database 17 that manages a frequency band of the entire system in order to distribute contents by using the CMTS 31 A function of determining the usage status of the relay-related device and the usage status of the frequency band for each RF cable to which the requesting user terminal is connected, and securing the QoS of the network path and the bandwidth of the RF cable to which the distribution requesting user is connected. HaveNote that the resource management database 16 and the frequency management database 17 do not need to be individually independent databases, and may have a configuration in which the same database is divided into areas to store necessary information.
[0030]
The router 14 checks the header of the IP packet, and relays the packet in a state where QoS can be secured as described above. The router 14 has a queue mechanism and a schedule management mechanism, and each IP packet is transmitted to the same destination traffic. Is managed for each flow defined in. Further, the router 14 has a function of managing a transmission band of a specific communication channel between routers based on RSVP (Resource Reservation Protocol) transmitted from the distribution server 12 and securing a resource for realizing necessary QoS. I have.
[0031]
The network 20 connects the head-end system 10 accommodating various servers 11 to 13 necessary for executing the streaming distribution and a large number of distribution HUBs 30 accommodating the CMTS 31 installed at a remote place. Is a transmission line formed in a ring shape.
[0032]
Each distribution HUB 30 serves as a distribution base for a large number of users and serves as a LAN concentrator having a repeater function or a switching function for accommodating the RF cable 40, and at least the CMTS 31 accommodates the same. Have been. This CMTS 31 is a kind of network relay device.
[0033]
The CMTS 31 is basically a cable router having an RF interface and having the same function as the router 14. That is, similarly to the router 14, a queue mechanism and a schedule management mechanism are provided.
[0034]
The IPB (IP streaming set-top box) 51 receives an IP packet corresponding to the viewing request content, and decodes data relating to higher-level video and audio such as an application included in the packet in accordance with a CODEC (code / decode). It has a function of executing processing and displaying the result on a user terminal 52 including a television TV, a CRT, and a liquid crystal monitor.
[0035]
Therefore, according to the above-described embodiment of the IP streaming system, the policy server 13 manages the resource management database 16 that manages the resources for realizing the QoS of the network relay related device including the CMTS and the frequency band of the entire system. When the navigation server 11 receives a content viewing request from the user terminal 52 including the IPB 51, the frequency management database 17 notifies the distribution server 12 of the content viewing request. An inquiry is made to the policy server 13 as to whether the QoS information can be secured together with the time information together with the request source information. The policy server 13 refers to the resource management database 16 to determine the use status of the network relay related device including the CMTS 31, and refers to the frequency management database 17 to determine the frequency of each RF cable to which the requesting user terminal is connected. Since the use status of the band is determined, it is possible to secure the QoS of the network path and the band of the RF cable connected to the distribution request source user. Can be delivered to terminals.
[0036]
(3) Configuration data examples of the resource management database 16 and the frequency management database 17.
[0037]
* About the resource management database 16.
[0038]
In general, the resources of the network relay-related devices for realizing QoS are limited, so that the bandwidth that can guarantee QoS is naturally limited. The router 14 accommodated in the head-end system 10 shown in FIG. 1 and the bandwidth that can be secured by, for example, the CMTS (1) 31 and the CMTS (2) 31 accommodated in each distribution HUB 30 are processed by their own CPU and software. It is limited by its capacity and has only 16 Mbps transfer capability per RF interface. Furthermore, the number of queues is "32" due to the limitation of memory in terms of the number of flows that are QoS management units. However, if 32 different flows can be processed per RF interface, for example, it is necessary for content distribution. Assuming that the minimum bandwidth is 500 kbps, the resource of each network relay-related device is limited to 32 at 500 kbps with respect to 16 Mbps, which is the transfer capability for each RF interface (see the band number in FIG. 4).
[0039]
Incidentally, examples of the configuration data of the resource management database 16 include a user name, an IP address of a user (IPB), route information from the distribution server 12 (for example, a network relay device name), a network relay device name, an interface name, and a band number. , Used band, use start time, expected use time (or expected end time), delay time, and the like.
[0040]
* About the frequency management database 17.
[0041]
The RF interface of the CMTS 31 can use one fundamental frequency (6 MHz) per tuner circuit. When the modulation of the 64QAM system is used as described above, the transmission speed becomes 27 Mbps. Among them, when the downstream execution speed is estimated to be 20 Mbps in consideration of the overhead of various protocols, the user receiving the service must be in the speed range.
[0042]
Incidentally, examples of the configuration data of the frequency management database 17 include a user name, an IP address of a user (IPB), a network relay device name, an interface name, a usable band, a used band number, a use start time, and an expected use time (or (Expected end time), used content address (URL), and the like.
[0043]
(4) The operation of the system shown in FIG. 1 or the IP streaming distribution method according to the present invention (see FIGS. 2 and 3).
[0044]
First, the policy server 13 stores, in the resource management database 16, information such as the band used by the network relay-related device including the CMTS 31 in the resource management database 16, and stores the information such as the frequency band of the RF cable 40 into the frequency. Initialization for appropriate management, such as storage in the management database 17, is performed (S1: policy server initialization step).
[0045]
In this state, when the user activates the IPB 51 and performs an operation for requesting the menu screen of the EPG, the menu screen request information is transmitted via the CMTS 31 and the network 20 based on the request source information such as its own IP address, and the navigation server 11. (S2). Here, the navigation server 11 distributes the menu screen of the EPG owned by itself to the IPB 51 owning the request source information of the specific user based on the screen request (S3). This menu screen is displayed on the user terminal 52. From the menu screen, the user can view buttons for each genre (action, drama), contents recommended by the system provider, and the like.
[0046]
Here, when the user designates a multimedia content such as a specific video from the menu screen displayed on the user terminal 52, a video content viewing request is transmitted from the corresponding IPB 51 based on its own request source information such as an IP address. You. The navigation server 11 of the head end system 10 receives the request source information and the video content viewing request sent from the user terminal via the CMTS 31 and the network 20, and receives the content viewing request (S4). These steps S2 to S4 correspond to a content request receiving step.
[0047]
The navigation server 11 notifies the distribution server 12 after receiving the viewing request of the content such as the video specified by the user (S5).
[0048]
The distribution server 12 reads the distribution request content, the band information necessary for distributing the content, the required distribution time information, and the like from the distribution information database 15 managed by itself, and sends the information to the policy server 13 together with the request source (destination) information. It transmits and inquires whether it can be distributed from the viewpoint of ensuring QoS (S6). These steps S5 and S6 mean an inquiry step.
[0049]
Here, the policy server (bandwidth broker) 13 acquires the network route information for distributing the requested content from the resource management database 16 based on the request source information (S7), and further obtains the request source information and the required bandwidth information ( (For example, 500 kbps), referring to the information stored in the resource management database 16 for all the network relay related devices including the CMTS 31 existing on the network route to the request source and the router 14 in the head end system 10, It is determined whether there is a resource capable of realizing QoS having a bandwidth of 500 kbps (S8). When it is determined that there is no resource, the policy server 13 replies to the distribution server 12 that distribution is impossible. At this time, the possible delivery time is also answered based on the estimated use time information (S9). Then, a new external input wait state is entered.
[0050]
When the policy server 13 determines in step S8 that there is a resource for realizing the QoS, the items specified in the resource management database 16 include, for example, the band number identification and the band number corresponding use band as shown in FIG. The band use information such as setting of “1” of the above and writing of the use start time is updated (S10). These steps S5 to S10 correspond to a resource securing determination step.
[0051]
Further, the policy server (band broker) 13 refers to the frequency management database 17 shown in FIG. 5 based on the request source information and the required band information, and corresponds to the RF cable 40 to which the request source IPB 51 is currently connected. It is determined whether or not the interface has a free space of the 500 kbps band (S11). Here, if there is no available bandwidth, the distribution server 12 is replied to the effect that distribution is not possible. At the same time, the distribution time is also returned based on the expected use time information. In addition, the resource management database 16 is updated to release the resources secured in step S10 (S12).
[0052]
On the other hand, when it is determined in step S11 that there is a free band in the interface corresponding to the RF cable 40, the policy server 13 determines whether the content distribution request of the requesting user exceeds the upper limit of the service. (S13) If it is determined that the bandwidth is not exceeded, the distribution server 12 is replied to the distribution server 12 that distribution is possible, and the frequency management database 17 is updated for the use of the band (S14). Steps S11 to S14 correspond to a band securing determination step.
[0053]
Here, when the distribution server 12 receives a response indicating that distribution is possible from the policy server 13, the distribution server 12 checks the actual bandwidth used by the network relay-related device including the CMTS 31 using a protocol such as RSVP and secures resources to be used. (S15).
[0054]
As the RSVP protocol, normally, a path message is transmitted from the distribution server 12, and the router 14 and the CMTS 31 sequentially check whether the conditions (bandwidth, delay time, and the like) of the path message are valid, It reaches the IPB 51 that is the content distribution request source. Upon receiving the path message without any error, the IPB 51 transmits a resv message to the distribution server 12. The CMTS 31 and the router 14 allocate and reserve actual resources based on the resv message transmitted from the IPB 51.
[0055]
Upon receiving the resv message, the distribution server 12 distributes actual contents such as video to the IPB 51 that has requested distribution using the resources of the reserved network relay-related device and the frequency band of the RF cable 40 (S16). Steps S15 and S16 mean a content distribution step.
[0056]
When the transmission of the content is completed, the distribution server 12 notifies the policy server 13 of the end of transmission of the requested content (S17). Upon receiving the transmission end information, the policy server 13 releases the information of the bandwidth used for distribution of the corresponding content in both management databases 16 and 17 (S18). Steps S17 and S18 mean a band securing information release step.
[0057]
Therefore, according to the above-described embodiment of the IP streaming distribution method, the step of receiving the viewing request content from the user terminal side, the notification to the distribution server 12 of the navigation server 11 that has performed the reception, and the distribution by the distribution server An inquiry step of acquiring necessary bandwidth information of content and time information necessary for distribution, and inquiring of the policy server 13 for QoS realization, and further a step of determining resource reservation and use bandwidth reservation by the policy bar 13. By adopting the step of notifying the distribution server 12 when the content can also be secured, it is possible to secure the resources and the bandwidth used, and to reliably distribute the viewing request content while securing the QoS.
[0058]
(5) An example of an actual operation process of the policy server 13 (see FIGS. 2 to 5).
[0059]
As a premise of the service, the contents described in * below are set.
[0060]
* The content requires a transmission rate that is an integral multiple of 500 kbps depending on the video quality, audio quality, and the like, so it is assumed that there are types from 500 kbps to 2 Mbps. For example, 1 Mbps is required for high-quality video content, and 500 kbps is required for medium-quality video.
[0061]
* It is assumed that the policy server 13 determines whether or not to use a service for each service (for example, viewing one movie) according to the status of resources and the like.
[0062]
* The transmission speed of each interface (per 6 MHz band) of the CMTS 31 is 27 Mbps in the case of the 64QAM modulation method, but the effective speed is set to 20 Mbps because of the overhead of various protocols.
[0063]
* The bandwidth that can be secured by the router 14, the CMTS (1) 31, and the CMTS (2) 31 is 16 Mbps for each interface, and the number of manageable flows is 500 kbps and 32.
[0064]
* Normally, the best-effort communication at a maximum of 2 Mbps per IPB 51 is guaranteed, but when content distribution is requested, viewing based on QOS management is possible within a range up to an integer multiple of 500 kbps, for example, up to 2 Mbps.
[0065]
* The number of connected IPBs 51 per interface of CMTS (1) 31 and CMTS (2) 31 is 50. That is, when the usage rate is equal to or higher than 20% of the 50 units, the usable speed of each user becomes 2 Mbps or less (20 Mbps ÷ (20% of 50 units) = 2 Mbps).
[0066]
The detailed operation of the actual policy server 13 under the above setting conditions will be described.
[0067]
(1) Upon receiving a video content distribution request from the navigation server 11 based on request source information such as an IP address, the distribution server 12 receives bandwidth information (for example, 500 kbps) required for content distribution stored in the distribution information database 15. ) And the required distribution time information (for example, 2 hours), and inquires of the policy server 13 whether or not distribution is possible, together with the request source information (S6 in FIG. 2).
[0068]
(2) The policy server 13 uses the resource management database 16 with the IP address serving as the request source information as a key to check the interface with the CMTS (1) 31 to which the distribution request source user is connected. The network route information from the server 12 to the user IPB 51, the relay device name (if there is more than one), and the interface name are searched (S7 in FIG. 2). For example, the user A is designated, and the router 14 / interface 1 and the CMTS (1) 31 / interface 1 (see FIG. 4) are acquired.
[0069]
(3) Next, the policy server 13 refers to the resource management database 16 on the basis of the request source information (usually, an IP address) and the required bandwidth information received from the navigation server 11, and executes a network up to the request source IPB 51. It is determined whether the router 14 and the CMTS (1) 51 existing on the middle route can secure a band (S8 in FIG. 2). Specifically, as shown in FIG. 4, in the CMTS (1) / interface 1, of the 32 resources (500 kbps) for realizing the QoS of the CMTS (1), the band numbers “1” and “ Since only "2" and "3" are used and it can be seen that the setting is still sufficiently possible, the band number "4" is specified in response to the current distribution request, and the corresponding band item is used. Set "1" and enter the usage start time. Although not shown in the resource management database 16, the process is similarly executed for the router 14 / interface 1.
[0070]
{Circle around (4)} Further, the policy server 13 refers to the frequency management database 17 based on the request source information and the necessary band information, and checks the CMTS (1) / interface 1 (the RF cable 40 to which the request source IPB is currently connected). ) Determine whether there is a vacancy of the 500 kbps band (S11 in FIG. 3). Specifically, the CMTS (1) / interface 1 is specified, and the limitation (for example, a total of 20 Mbps) derived from the frequency allocation per RF interface is compared with the currently used band. Here, as shown in FIG. 5, the total used frequency band of the RF interface of the CMTS (1) / interface 1 is 3, which is not used than the 1.5 Mbps band and is 20 Mbps or less. There is no problem with band usage.
[0071]
{Circle around (5)} The number of bands used by the IP address (for example, 10.1.3.3) of the distribution requesting user this time is 0, and the upper limit value is 2 Mbps or less for each user, so there is no problem. An available band can be used (S13 in FIG. 3).
[0072]
{Circle around (6)} Based on the result of referring to the two databases 16 and 17 described above, the policy server 13 replies to the distribution server 12 that the distribution in response to the distribution request of the user IPB 51 this time is possible (S14 in FIG. 3). .
[0073]
Therefore, according to the above-described embodiment of the policy server 13, it is possible to appropriately determine the resource reservation and the bandwidth use by referring to the data stored in the resource management database 16 and the frequency management database 17, and We can provide appropriate answers necessary for the distribution of.
[0074]
(6) Configuration and operation processing example when the CMTS 31 includes the resource management database 32 and the frequency management database 17.
[0075]
In the above-described system example, a configuration example in which resource management is unified by the policy server 13 has been described. In this example, as shown in FIG. 6, each CMTS 31 has a database 32 and 33. In other words, the management of resources and frequency bands downstream from each CMTS 31 is an example in which necessary information is stored and managed in databases 32 and 33 managed by each CMTS 31. The databases 32 and 33 store the same configuration data as those of the resource management database 16 and the frequency management database 17 described above. Particularly, the same data as those shown in FIGS. Shall be stored.
[0076]
Next, the operation of the system including the CMTS 31 including the databases 32 and 33 will be described with reference to FIGS.
[0077]
First, when the CMTS 31 starts its operation, the CMTS 31 performs initialization for managing information such as a used band and information such as a frequency band of the RF cable 40 in order to realize QoS (S21: initialization step).
[0078]
In this state, when the user starts the IPB 51 and performs a request operation of the EPG menu, screen request information is transmitted to the navigation server 11 via the CMTS 31 and the network 20 based on request source information such as its own IP address. (S22). Here, the navigation server 11 distributes the request source information of a specific user to the owning IPB 51 (S23). This EPG menu screen is displayed on the user terminal 52. From the menu screen, the user can view buttons for each genre (action, drama), contents recommended by the system provider, and the like.
[0079]
Here, when the user designates a multimedia content such as a specific video from the menu screen displayed on the user terminal 52, a video content viewing request is transmitted from the corresponding IPB 51 based on its own request source information such as an IP address. You. The navigation server 11 of the head end system 10 receives the request source information and the video content viewing request sent from the user terminal side via the CMTS 31 and the network 20, and receives the content for which the viewing request has been made (S24). Steps S22 to S24 correspond to a content request receiving step.
[0080]
The navigation server 11 notifies the distribution server 12 after receiving the viewing request of the content such as the video specified by the user (S25).
[0081]
The distribution server 12 reads route information, band information necessary for content distribution, required distribution time information, and the like from the distribution information database 15 managed by the distribution server 12 based on the request source information, and requests source (destination) information. At the same time, it transmits to the policy server 13 (S26).
[0082]
When the policy server 13 receives the request source information, the route information, the bandwidth information necessary for distributing the content, and the required distribution time information, the request source information and the required bandwidth information (for example, 500 kbps), the required distribution time information, and the like are provided. Is notified to the CMTS 31 existing on the request source side network route, and a service is requested (S27).
[0083]
Here, the CMTS 31 acquires the interface name based on the request source information (S28), refers to the information stored in the resource database 32 based on the interface name, and sets the interface name to 500 kbps in terms of QoS from the viewpoint of QoS. It is determined whether there is a resource that can secure a band (S29). If there is no resource that can secure a band, the CMTS 31 replies to the policy server 13 that distribution is impossible. At this time, the possible delivery time is also answered based on the expected use time information (S30).
[0084]
If the CMTS 31 determines in step S29 that there is a resource for which QoS can be secured, the items specified in the resource management database 32 include, for example, band number identification and “ 1) Update band use information such as setting, writing of use start time, and the like (S31). These steps S28 to S31 correspond to a resource securing determination step.
[0085]
Further, the CMTS 31 refers to the frequency management database 33 shown in FIG. 4 based on the request source information and the required bandwidth information, and determines whether or not the corresponding interface has a free space of the 500 kbps bandwidth (S32). Here, if there is no free space in the band, a response is made to the policy server 13 that there is no resource, but at the same time, a possible distribution time is also returned based on the estimated use time information. Further, the resource management database 32 is updated to release the resources secured in step S31 (S33).
[0086]
On the other hand, when it is determined in step S32 that there is an available band frequency in the interface, the CMTS 31 determines whether the content distribution request of the requesting user exceeds the upper limit of the service (S34), and does not exceed the upper limit. If it is determined that the band can be distributed, the response is sent to the policy server 13 and the frequency management database 33 is updated for the use of the band (S35). These steps S32 to S35 correspond to a band securing determination step.
[0087]
Here, the policy server 13 replies to the distribution server 12 that distribution is possible (S36). When receiving a response indicating that distribution is possible from the policy server 13, the distribution server 12 checks the actual bandwidth used by the network relay-related device including the CMTS 31 using a protocol such as RSVP, and secures resources to be used ( S37).
[0088]
In other words, the path message is transmitted from the distribution server 12 and reaches the IPB 51 that is the content distribution request source while sequentially checking the router 14 and the CMTS 31 in this order. Upon receiving the path message without any error, the IPB 51 transmits a resv message to the distribution server 12.
[0089]
Upon receiving the resv message, the distribution server 12 transmits the actual content such as video to the IPB 51 that has requested distribution using the resources of the reserved network relay-related device and the frequency band of the RF cable 40 (S38: content distribution step). ). When the distribution server 12 terminates the distribution of the content, the distribution server 12 transmits transmission end information to the CMTS 31 via the policy server 13 (S39). The CMTS 31 releases information on the bandwidth used for the distribution of the corresponding content in both management databases 32 and 33 (S40).
[0090]
Therefore, according to the embodiment of the CMTS 31 which is a network relay device as described above, the CMTS 31 includes the resource management database 32 and the frequency management database 33 having the same information as the policy server 13 so that the CMTS 31 By referring to the contents of the databases 32 and 33, the same functions and effects as those of the policy server 13 can be achieved.
[0091]
In the above embodiment, the resource management database 16 and the frequency management database 17 are provided for realizing QoS. However, either one of the databases 16 or 17 is provided to realize QoS from the viewpoint of resources or frequencies. It may be.
[0092]
Further, in the embodiment, both the management databases 32 and 33 are provided on the CMTS 31 side. However, one of the management databases 32 and 33 may be provided on the CMTS 31 side, and in this case, the other management database 33 or 33 may be provided. 32 is installed on the policy server 13 side.
[0093]
Further, when both management databases 32 and 33 are provided on the CMTS 31, the policy server 13 may be deleted from the system.
[0094]
In addition, the present invention is not limited to the above-described embodiment, and can be variously modified and implemented without departing from the gist thereof. Further, the embodiments can be implemented in combination as much as possible, and in that case, the effect of the combination can be obtained. Furthermore, each of the above embodiments includes various upper and lower stage inventions, and various inventions can be extracted by appropriately combining a plurality of disclosed components. For example, when an invention is extracted because some constituent elements can be omitted from all the constituent elements described in the means for solving the problem, if the extracted invention is implemented, the omitted part is omitted. Is appropriately supplemented by well-known conventional techniques.
[0095]
【The invention's effect】
As described above, according to the present invention, in response to a content viewing request from a user, the usage status of network resources is checked, network resources are effectively used while securing QOS, and the viewing request content is appropriately distributed. Possible IP streaming system, policyServer and IPCan provide a streaming distribution method.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram showing an embodiment of an IP streaming system according to the present invention.
FIG. 2 is a flowchart illustrating an operation of the system illustrated in FIG. 1 and an embodiment of an IP streaming distribution method according to the present invention.
FIG. 3 is a flowchart subsequent to FIG. 2 for explaining an operation of the system shown in FIG. 1 and an embodiment of an IP streaming distribution method according to the present invention;
FIG. 4 is a diagram showing an example of a data configuration of a resource management database shown in FIG.
FIG. 5 is a diagram showing an example of a data configuration of a frequency management database shown in FIG. 1;
FIG. 6 is a system configuration diagram showing another embodiment of the IP streaming system according to the present invention.
FIG. 7 is a flowchart illustrating an operation of the system shown in FIG. 6 and an embodiment of an IP streaming distribution method according to the present invention.
FIG. 8 is a flowchart following FIG. 7 for explaining an operation of the system shown in FIG. 6 and an embodiment of an IP streaming distribution method according to the present invention;
[Explanation of symbols]
10. Head-end system
11 ... Navigation server
12 ... distribution server
13 ... Policy server
16 Resource management database
17: Frequency management database
20 ... Network
30 ... Distribution HUB
31 CMTS (Network Relay Device)
32 ... Resource management database
33: Frequency management database
40 ... RF cable
51 ... IPB
52 ... User terminal

Claims (5)

An IP streaming system in which a distribution server distributes a requested content to a requesting user terminal based on a content viewing request transmitted from each user terminal via a CMTS and a network,
Prior to distributing the requested content, the distribution server for sending an inquiry as to whether QoS for distributing the content can be secured;
A resource management storage unit for storing time information related to the status of resources existing on the network path to each of the user terminals and resource use, and storing time information related to the use status and band use of the frequency band of the entire system; A frequency management storage unit that performs the resource management when receiving an inquiry about QoS reservation including the request source information and the required band information from the distribution server based on a content viewing request including the request source information from the user terminal. A first determining unit that determines whether or not there is a resource for securing the QoS relating to the viewing request content by referring to a storage unit, and a case where a QoS securing inquiry including the request source information and the required bandwidth information is received from the distribution server. , The user terminal that has requested viewing is connected with reference to the frequency management storage means. A second determining means for determining whether or not a frequency band is vacant in the network, and a resource of a network relay-related device including the CMTS present on a network path for distributing the content obtained from the first and second determining means. Notifying the distribution server of the availability of QoS reservation based on the usage status and the usage status of the frequency band of the cable to which the user terminal is connected. An IP streaming system comprising: a policy server provided with means for notifying the distribution server of a distribution available time from related time information. An IP streaming system in which a distribution server distributes a requested content to a requesting user terminal based on a content viewing request transmitted from each user terminal via a CMTS and a network,
Prior to distributing the requested content, the distribution server for sending an inquiry as to whether QoS for distributing the content can be secured;
A resource management storage unit for storing time information related to the status of resources existing on the network path to each of the user terminals and resource use, and storing time information related to the use status and band use of the frequency band of the entire system; A frequency management storage unit that performs the resource management when receiving an inquiry about QoS reservation including the request source information and the required band information from the distribution server based on a content viewing request including the request source information from the user terminal. A first determining unit that determines whether or not there is a resource for securing the QoS relating to the viewing request content by referring to a storage unit, and a case where a QoS securing inquiry including the request source information and the required bandwidth information is received from the distribution server. , The user terminal that has requested viewing is connected with reference to the frequency management storage means. A second determining means for determining whether or not a frequency band is available in the network, a use status of resources of a network relay-related device existing on a network route for distributing the content obtained from the first and second determining means, and Notifying the distribution server whether or not QoS can be secured based on the use status of the frequency band of the cable to which the user terminal is connected, and when QoS is not secured, time information relating to the resource use and the band use And a means for notifying the distribution server of a possible distribution time from the CMTS. In the IP streaming system according to claim 1 or 2,
If it is determined that there is a vacancy in the frequency band of the cable and that the QoS can be ensured based on the resource usage status, it is determined whether the content viewing request from the user terminal exceeds the upper limit of the communication service. The IP streaming system is characterized in that when it is determined that the content has not been exceeded, the delivery server is notified that the content requested to be viewed can be distributed while ensuring QoS. In an IP streaming system that distributes a content requested to be viewed based on a content viewing request from each user terminal,
Resource management storage means for storing time information related to the status of resources and resource usage existing on the network path to each of the user terminals,
Frequency management storage means for storing time information related to the use status and band use of the frequency band of the entire system,
Upon receiving request source information and required bandwidth information from the outside in response to a content viewing request from the user terminal, refer to the resource management storage unit to determine the presence or absence of a resource for ensuring QoS for the viewing requested content. First determining means;
Upon receiving the request source information and the required band information from the outside, the second determining unit refers to the frequency management storage unit and determines whether or not a frequency band is vacant in a cable to which the user terminal having requested viewing has been connected. And the use status of the resources of the network relay-related device existing on the network route for distributing the content obtained from the first and second determination means and the use status of the frequency band of the cable to which the user terminal is connected Means for judging whether or not QoS can be ensured based on the above information, and, when QoS has not been secured, means for calculating a deliverable time from time information relating to the resource use and the bandwidth use. . A plurality of user terminals for requesting content viewing and a CMTS in which the plurality of user terminals are connected via a cable, and the content requested to be viewed is transmitted to the user terminal based on the viewing request from the user terminal. In an IP streaming system that distributes via a network,
When a menu screen request is received from a certain user terminal based on request source information, a menu screen is transmitted to the user terminal, and a content request receiving step of receiving a viewing request content from the user terminal,
An inquiry step of, when receiving the viewing request content in this step, reading the distribution request content stored in advance, the band information necessary for distributing the content, and the required distribution time information, and inquiring whether QoS can be secured;
Based on this inquiry, reference is made to resource information existing on the network route to the requesting user terminal and time information related to resource use stored in advance, and it is determined whether there is a resource for securing QoS for the viewing request content. Resource securing determination step;
A band for determining whether or not a frequency band is vacant in a cable to which the user terminal is connected, by referring to a frequency management storage unit that stores time information relating to the use status of the frequency band and the band use of the entire system based on the inquiry. Securing determination step;
Distributing the viewing request content to the requesting user terminal when it is determined that QoS can be secured by each of the determining steps;
Obtaining a deliverable time from time information related to the resource use and the band use when it is determined that the QoS is not secured in each of the determination steps.

Images