CN1062100C - CATV-based medium transmitting control method and network for realizing comprehesive business - Google Patents

Abstract

A new method of medium feeding and fetching control for realizing integrated services based on a cable TV network and an integrated service network using the method. This method makes full use of the characteristics of the cable TV network, uses the uplink channel to partially receive tokens and/or information, and only transmits the tokens to those nodes that may send information, shortens the transmission distance and time, and thus reduces the channel occupation The amount improves the effective utilization of the channel. The integrated service network is composed of a cable TV network or a part thereof, a communication processor, a modem, user terminal equipment and a radio frequency mixer, etc. Communication processors can be interconnected, and can also be connected with Internet servers, video-on-demand centers, commodity information centers, and public networks to provide multiple services.

Description

Media delivery and retrieval control method and network for realizing integrated services based on CATV network

The present invention relates to a medium access control (MAC) method for realizing integrated services based on a cable television (CATV) network and a CATV integrated service network constructed by the method.

The technology of realizing or constructing an integrated service network or transmitting multiple information based on the CATV network is already known. The integrated service network of CATV network with shape structure and token bus MAC method overcomes the shortcomings of the previous CATV integrated service network, such as low speed, special purpose, and small scope, and can form a large-scale and multi-purpose CATV integrated service network; however, due to information And the token should be sent to the uplink channel, and then sent to the downlink channel to the receiving node after being converted by the carrier frequency converter, so the transmission time is long, and the uplink and downlink channels are occupied at the same time, which reduces the effective utilization of the channel. On the other hand, the tokens in the above-mentioned patent application generally need to traverse all nodes, regardless of whether the nodes want to send data, which takes more time and reduces the effective efficiency.

"World Cable TV Information" in 1996, the seventh issue, the third volume "Multifunctional Development of Cable TV Network Based on HFC Mode", the article mentions: general CATV network, especially in the CATV network of fiber-optic coaxial cable hybrid (HFC), Part of the frequency band is specially designated for transmitting downlink and uplink data signals. For example, 5-42MHz can be allocated for transmitting uplink data signals, and 550-750MHz can be allocated for transmitting downlink data signals. The uplink data channel refers to a frequency band specially allocated for transmitting uplink data signals, and the uplink data channel is referred to as an uplink channel for short. Downlink channels include downlink data channels and analog channels, and analog channels are used to transmit common TV programs. Due to the directivity of the amplifier used in the CATV network, the downlink information can be transmitted to each user node, but the uplink information is not: some user nodes can receive the information sent by a user node through the uplink channel, while other user nodes can receive it. Not receive. We call a group of user nodes and their transmission channels that can receive the uplink information sent by any user node through the uplink channel a branch, or more generally, we regard the uplink data channel as shown in Figure 1 A one-way tree structure is shown, the user nodes 102 are distributed on the branches of the tree, and the central control node 101 is located at the root of the tree. When information is transmitted on this one-way channel, the experienced nodes can receive it, and the unexperienced The node cannot receive it. The token, which is a special control information, can also be received by the experienced nodes. Therefore, in theory, user nodes can not only receive information and tokens from the downlink channel, but also partially receive information and tokens from the uplink channel.

The purpose of the present invention is to provide a new MAC method based on CATV network to realize integrated services, so that user nodes can receive tokens and/or information from the uplink channel, and the distance of communication is shortened, thereby reducing delay and reducing channel occupation Quantity, improve the effective utilization rate and capacity of the channel, and use this method to construct the CATV integrated service network to overcome the shortcomings of the above-mentioned CATV integrated service network, such as long token transfer time and low channel effective utilization rate.

In order to achieve the above object, the CATV network of the present invention realizes the MAC method of integrated service, the downlink information is transmitted by broadcast mode, and its main point is that the uplink information adopts the token tree mode to transmit.

The token tree method can be one of the following two methods:

Method 1. The token is first transmitted to the last user node of a branch through the downlink channel. The user node can send data after receiving the token, and then transmit the token to the previous user node of the branch through the uplink channel , ... and so on until the last user node of the branch that receives the token transmits the token to the central control node through the uplink channel, and the central control node then transmits the token to the last node of the next branch through the downlink channel User nodes, ... and so on until the token traverses all branches and then recycles.

Method 2. The token is only sent to those nodes that may want to send information, which specifically includes the following main steps:

(1), the central control node establishes or revises the table (hereinafter referred to as the token table) about the user nodes that each branch may send information and the sequence of obtaining tokens according to the user's request;

(2), the central control node broadcasts the token table through the downlink channel;

(3) Each user node transmits tokens according to the sequence specified in the received token table, and sends information when holding tokens.

The process of establishing and modifying the token table by the central control node includes the following main steps:

(1), the central control node can broadcast a user service request inquiry frame at regular intervals;

(2), the user node desiring to request a service judges whether to send a service request frame after receiving the inquiry frame, if not, immediately send a service request frame through the uplink channel, otherwise, wait for a period of time and then send the service request frame;

(3) The central control node receives the service request frame, and establishes or modifies the token table accordingly.

The sending of downlink information may not be limited by tokens.

Another aspect of the present invention——a kind of integrated service network realizing above-mentioned MAC method, is made up of cable television network or its part, communication processor, modem, radio frequency mixer and user termination equipment etc., it is characterized in that described communication The processor and the modem constitute the central control node in the MAC method, the communication processor broadcasts the user service request query frame, receives the service request frame, and establishes or modifies the token table of each branch accordingly, and passes The modem and the downlink channel broadcast the token table; the user terminal device and the computer, telephone or television set connected to it constitute the user node, and the user terminal device receives the user service request query frame and needs to send Send the service request frame after receiving the user service request inquiry frame during the data, send the information when holding the token and transmit the token to the next user terminal device or communication processor in the order specified by the token table; the radio frequency The mixer mixes the CATV signal and the downlink data channel signal and transmits it to the user node, and transmits the uplink channel signal to the modem.

In the present invention, downlink information may include ordinary broadcast TV programs, video-on-demand programs, video game programs, (computer) data, voice, commodity information, and other service information. In addition to ordinary broadcast TV programs, data and compressed video-on-demand programs, video game programs, voice, commodity information and other service information that can be converted or encoded into data transmission can be transmitted through the data channel. Uplink information may include data, voice, and user commands. Uplink data or voice and user commands that can be converted or encoded into data transmission can be transmitted through the uplink data channel.

Because the present invention makes full use of this characteristic of the tree structure of CATV network, utilizes the up channel to receive information and/or token partly, and token is only transmitted to those nodes that may want to send information, so shorten token and /or the transmission distance and time of information, which reduces the channel occupancy and improves the effective utilization of the channel. In addition, using the token method can control the delay in sending information and realize real-time services such as telephone calls.

Embodiments of the present invention will be described below in conjunction with the accompanying drawings. In the attached picture:

Fig. 1 is the schematic diagram that illustrates that the upstream channel on the CATV network is a unidirectional tree structure;

Fig. 2 is the structural representation of a kind of token management table in the central control node in the MAC method of the present invention;

FIG. 3A is a flowchart of an embodiment of the MAC method of the present invention;

FIG. 3B is a specific flowchart of step S302 shown in FIG. 3A;

Fig. 4 is the structural representation of the first embodiment of CATV integrated service network of the present invention;

FIG. 5 is a schematic structural diagram of the user terminal device shown in FIG. 4;

Fig. 6 is the structural representation of the second embodiment of CATV integrated service network of the present invention;

Fig. 7 is a schematic structural diagram of the third embodiment of the CATV integrated service network of the present invention.

Referring to FIG. 2 , this figure shows a schematic structural diagram of a token management table in the central control node in the MAC method of the present invention. As shown in Fig. 2, described central control node is provided with a storage area, wherein a part is used for storing the user node address (or numbering) of each branch and its state-whether it is a node that may want to send information, this It is identified by marking, such as "*" to mark that the user node will send information, and the other part stores pointers to each branch (called a branch pointer table). When sending a branch token table, find the starting position of the corresponding branch user node through the branch pointer table, and extract the user nodes marked with "*" to form a sequence, which is the token table of the branch at this time.

Referring to FIG. 3A, this figure shows a flowchart of an embodiment of the MAC method of the present invention. The main steps of the MAC method of the present invention will be described in detail below in conjunction with this figure:

First in step S301, the token table in the central control node is initialized as empty (that is, each user node has no "*" sign); after that, complete step S302 in time t: service request login (will be detailed in Fig. 3B Then enter step S303: a pointer F is set to point to the starting position of the branch pointer table shown in Figure 2; then go to step S304: the central control node determines the corresponding branch user node by the branch pointer table pointed to by the pointer F From the starting position of the branch, the user nodes with the sign of "*" that may want to send information are drawn from the branch to form a sequence, that is, the token table of the branch at this time, and the token and the token are simultaneously broadcast through the downlink channel Table, each user node receives the token table, and stores the token table, the user node in the first place in the token table occupies the token at this time; then execute step S305: the user node holding the token sends a certain amount of information, and Store the information of receiving the token in its own storage device, and erase the previously stored information indicating that the service request frame has been sent; then enter step S306: the node holding the token judges whether the information to be sent has been sent, If it has been sent, then in step S307, the user node sends a service termination request frame, and erases the previously stored information indicating that the token has been received, and the central control node receives the above service termination request frame, and changes the The status of the user node (remove the "*" number in its corresponding status column), and then go to step S308; on the other hand, if the judgment of step S306 is "No", then go directly to step S308: the user who holds the token The node judges whether the user node on the token table is empty (that is, whether there is no user node to send information after the user node in the branch), and if it is judged as "No", step S309 is performed: pass the token to The next user node on the token table, then repeat step S305; if S308 judges as "yes", then execute step S310: the user node holding the token hands over the token to the central control node, and then enters step S311 : the central control node judges whether the pointer F has pointed to the last position of the branch pointer table, if it is judged as "No", execute step S312: set the pointer F to point to the next position of the branch pointer table, then repeatedly execute step S304; such as S311 If it is judged as "yes", step S302 is repeatedly executed.

Figure 3B shows the specific process of step S302 in Figure 3A: first execute step S321: the central control node broadcasts a user service request inquiry frame through the downlink channel, and the user node receives the inquiry frame; then enter step S322: the The user node inquires from its own storage device whether the user node has received the token last time, and if so, does not respond to the user service request frame; otherwise, enter step S323: the user node inquires whether the user node has information needs Send, if there is no information that needs to be sent, do not respond to the user service request query frame; otherwise, enter step S324: the user node inquires whether the user node has sent the user request frame last time, if it is judged as "yes", execute step S325: Wait for a period of random time t', and then proceed to step S326; if S324 judges as "no", then directly proceed to step S326: the user node immediately sends a service request frame, and stores a message indicating that the service request frame has been sent, Described central control node receives service request frame, judges whether it is a complete, correct service request frame, as judged as " yes ", changes the state (shown in Fig. mark "*" in the status column corresponding to the user node), if the judgment is "No", it means that there is an error in the received request frame (such as a conflict, etc.), and the status of the user node requesting the service in the token table will not be changed. state.

The following changes can be made to the MAC method shown in Figure 3A as the second embodiment of the MAC method of the present invention: a clock timer is set in the original step S302, and a time period T is set at the same time, and according to the channel effective utilization rate, uplink The channel transmission rate and the rate at which the user node sends data determine the number of user nodes allowed to log in to the service request and the amount of information each node sends each time after broadcasting the user service request query frame each time, so as to ensure that the pointer F has pointed to in the original step S311. After the end of the branch pointer, the whole cycle process (including service request login, transfer token, sending information, etc.) takes no more than period T, and re-execute step S302 when the clock indicates that the time period T has expired.

It needs to be explained that the time t in step S302 of the method is set according to the transmission delay and the longest random waiting time, and the time period T in the second embodiment is set according to the effective utilization rate of the channel, the time t and token transfer Time and other settings. For example: the sum of the distances from the central control node to the user nodes at the end of each branch does not exceed 300km, the maximum distance from the user node does not exceed 75km, the uplink data rate is about 10Mbps, and real-time services such as ordinary telephones are provided to 100 users at the same time. Business and other non-real-time services, you can set T=20ms, t=1ms; another example: the sum of the distances from the central control node to the user nodes at the end of each branch does not exceed 30km, and the maximum distance from the user node does not exceed 1.5km, the uplink data rate is about 10Mbps, and provides real-time services such as ordinary telephones and other non-real-time services to 80 users at the same time. T=3ms and t=0.02ms can be set.

Referring to Fig. 4, this figure shows a schematic structural diagram of the first embodiment of the CATV integrated service network of the present invention. It can be seen from this figure that the integrated service network mainly includes a CATV network or a part thereof, a communication processor (CP) 401, a modem (M) 402, a radio frequency mixer 403, a branch front end 404, a distribution center 405, a user terminal equipment 406 and User equipment such as telephone/fax 407, computer 408, TV 409, etc. A communication processor 401, a modem 402, a radio frequency mixer 403, and a sub-front end 404 are connected in sequence, and the sub-front end is connected to several distribution centers 405, and the distribution center can be connected to several user terminal devices 406, and the user Terminating equipment is connected to specific user equipment such as telephones or fax machines, televisions, computers, etc. The communication processor 401 broadcasts the user service request query frame, receives the service request frame, establishes or modifies the token table according to it, and broadcasts the token and the token table through the modem 402 and the downlink channel; the user terminal device 406 Receive the service request query frame, send the service request frame after receiving the user service request query frame when the information needs to be sent, send the information to the upstream channel when the token is passed to the terminal device in the order specified by the token table, and send The token is sent to the next user terminal equipment in the order specified by the received token list; the radio frequency mixer 403 mixes the CATV signal and the downlink data channel signal and sends it to the user node, and sends the uplink channel signal to the The modem 402.

Referring to FIG. 5 , this figure shows a schematic structural diagram of the user terminal equipment shown in FIG. 4 . It can be seen from FIG. 5 that the user terminal equipment mainly includes a modem 501 , a receiver 502 , a transmitter 503 , a microprocessor 504 , a clock circuit 505 , a memory 506 , an uplink receiving table 507 and a function card 508 . The components work under the control of the microprocessor 504 and clock signals. The modem 501 can modulate uplink information to be sent and demodulate received downlink and uplink information. There are shift registers and buffer registers in the receiver 502 and the transmitter 503, which convert the received serial signals into parallel signals and temporarily store them, and then send them to the memory 506 through the bus; The signal is temporarily stored, converted into a serial signal and sent out. The token table received from the downlink channel and the token received from the downlink channel or the uplink channel are first stored in the memory, and after sending data (if there is data to be sent), the token is sent to the token table through the uplink channel. A user-terminated device. The uplink reception table 507 stores the address of the user node that can receive the information sent by the user node through the uplink channel. If the information is to be sent to these nodes, it can be delivered directly through the uplink channel; otherwise, it is sent to the central control node, and the central Control node forwarding. The function card 508 can be a computer communication card, a telephone interface card, a video decompression card or other function cards, and one user terminal device can be installed with any one, two or all of the function cards.

Referring to Fig. 6, this figure shows a schematic structural diagram of the second embodiment of the CATV integrated service network of the present invention. In this integrated service network, there are two communication processors (CP) 601 and (CP) 602 without direct contact, and each communication processor can be used as a central control node to construct an integrated service network as shown in Figure 4 (service network 1 , service network 2), but the CATV signal in service network 2 is provided by service network 1. The downlink information broadcast by CP 601 and the CATV signal are mixed by the RF mixer 606 and sent to the RF separator 609 by the sub-front end 608, and the RF separator 609 separates the CATV signal from it and sends it to the RF mixer connected to the communication processor 602 through the modem 605 The radio frequency mixer 607 mixes the CATV signal with the downlink data signal from the CP 602 and transmits it to the distribution center 611. The CP 602 sends data to the uplink data channel of the service network 1 through the modem 604 and the radio frequency splitter 609 . If the communication processor 602 is directly connected to the communication processor 601, the modem 604 can be removed.

Referring to Fig. 7, this figure shows a schematic structural diagram of the third embodiment of the CATV integrated service network of the present invention. The integrated service network differs from the above two embodiments only in that there are multiple communication processors 701, and each communication processor is connected through an optical cable to realize mutual communication. The communication processor 701 is also connected to the Internet server 702, video-on-demand center 703, and product information center 704, so as to realize services such as Internet access, video-on-demand, and TV shopping. The communication processor is connected to the public network 706 (such as the public telephone network, ISDN, packet switching data network, digital data network, etc.) through the public network interface device 705 to realize services such as long-distance calls and long-distance communications. The communication processor is also connected to Ethernet 708 through router 707 .

Although the present invention has been described above in conjunction with the embodiments, it is obvious that the protection scope of the present invention is not limited thereto, and those skilled in the art may also make various obvious changes, for example: in the third embodiment of the integrated service network of the present invention, the communication Processor 701 can also be connected by coaxial cable, ATM switching network or other communication media; Described communication processor 701 can only be connected with Internet server 702, video-on-demand center 703, commodity information center 704, public network 706 and Ethernet 708 One or more of the connected; and so on. Therefore, the protection scope of the present invention is determined only by the claims.

Claims (9)

1, a kind of medium based on cable television network realization integrated service send and gets control method, downlink information is pressed broadcast mode and is transmitted, it is characterized in that uplink information adopts token tree mode to transmit, and token only sends the node that those send information possibly to, specifically comprises following key step:

(1) central control node (101) asks to set up or revise the table (being called for short the token table later on) that relevant each branch sends the user node (102) of information possibly and obtains the sequencing of token according to the user;

(2) central control node (101) is by down going channel broadcasting token table;

(3) each user node (102) transmits token by the order of the token table regulation of receiving, and sends information when holding token.

2, access method is sent in medium control as claimed in claim 1, it is characterized in that the step of described foundation or modification token table comprises following key step:

(1) described central control node (101) can be broadcasted user's service request inquiry frame at regular intervals;

(2) judge whether to send the service request frame after the user node (102) of desire request service receives this inquiry frame,, send a service request frame by data feedback channel immediately if do not have, otherwise, wait for a period of time and send the service request frame again;

(3) central control node receives the service request frame, and sets up or revise the token table in view of the above.

3, access method is sent in medium control as claimed in claim 1 or 2, it is characterized in that described central control node to the described user node of each branch's least significant end apart from sum≤300km, ultimate range between described central control node and the described user node is 75km, upstream data rate is 10Mbps, can be simultaneously for 100 users provide service, the time interval of described central control node broadcasting user service request inquiry frame is 20ms.

4, access method is sent in medium control as claimed in claim 1 or 2, it is characterized in that described central control node to the described user node of each branch's least significant end apart from sum≤30km, ultimate range between described central control node and the described user node is 1.5km, upstream data rate is 10Mbps, can be simultaneously for 80 described user nodes provide service, the time interval of described central control node broadcasting user service request inquiry frame is 3ms.

5, a kind ofly realize the integrated services network of method as claimed in claim 1 or 2 based on the CATV net, comprise cable television network or its part, communication processor (401,601,602,701), modulator-demodulator (402,603,604,605), radio-frequency (RF) mixing (403,606,607) and ustomer premises access equipment (406,612,613), it is characterized in that described communication processor and described modulator-demodulator constitute described central control node (101), described communication processor broadcasting user service request inquiry frame, receive the service request frame, set up or revise the token table of each branch in view of the above, and broadcast this token table by modulator-demodulator and down going channel; Described user's head joint equipment and the computer that is attached thereto, telephone set or television set constitute described user node (102), described user's head joint equipment receives user's service request inquiry frame, after receiving user's service request inquiry frame, send the service request frame when need sending data, send information when holding token and send token to next user's head joint equipment or communication processor by the order of token table regulation; Described radio-frequency (RF) mixing is with CATV signal and the mixing of downlink data signal of communication and send described user node to, sends the data feedback channel signal to described modulator-demodulator.

6, integrated services network as claimed in claim 5, it is characterized in that each communication processor (701) links to each other by optical cable, coaxial cable or other communication medium or links to each other by the ATM switching network, can intercom mutually, described communication processor (701) also links to each other with Internet server (702), VOD center (703) or merchandise news center (704).

7, integrated services network as claimed in claim 5 is characterized in that described communication processor (701) is connected with public network (706) by public network interface equipment (705).

8, integrated services network as claimed in claim 5, it is characterized in that described user's head joint equipment (406,612,613) form by modulator-demodulator (501), receiver (502), transmitter (503), microprocessor (504), clock circuit (505), memory (506), up reception table (507) and function card (508).

9, integrated services network as claimed in claim 8, it is characterized in that described memory (506) storage is transformed into the information that data, token, token table and this head joint equipment of parallel signal will send through receiver (502), described function card (508) is Computer Communications Interface card, telephone interface card, video display decompress(ion) card or other function card, user's head joint equipment can install any, two kinds or repertoire card.

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