CN1398087A - Broad-band access system for MAN - Google Patents

Abstract

The invention discloses a broadband access system of a metropolitan area network, which comprises: a broadband metropolitan area network access layer of cell node equipment, building node equipment, and user node equipment through construction, and adopts optical fibers or five-category lines between the three node equipment Plus cable TV connection. Adopting the broadband access system of the metropolitan area network of the present invention can enable high-speed Ethernet access technology to realize broadband services, which can not only be popularized and applied to commercial users, but also can conveniently realize Ethernet broadband access for family users in residential quarters . The broadband access system of the present invention can also reduce the engineering quantity of the construction of the metropolitan area network, save the construction cost, facilitate the rapid promotion of broadband services by operators, and ensure the successful operation of the broadband network.

Description

Metropolitan Area Network Broadband Access System

Technical field:

The invention relates to a data communication metropolitan area network broadband access system, which belongs to the field of data communication. In particular, it relates to a broadband access system for data communication, which provides broadband access services to data users through coaxial cables of cable television.

Background technique:

Broadband metropolitan area network, also known as broadband metropolitan area data communication network, mainly refers to various data communication networks that provide broadband access covering the entire city. With the acceleration of urban informatization construction in various parts of our country in recent years, the construction of broadband metropolitan area network has become an important part of a city's informatization infrastructure. The emergence of the broadband metropolitan area network will make the city's information and communication organically integrated on the same platform, which includes the telephone voice service provided by the PSTN network, the TV program transmission provided by the cable TV network, and the online shopping that can be realized by the computer network. , Online medical treatment, online stock market trading, online teaching, VOD video on demand, video conferencing and other services. All these have promoted the implementation of projects such as "e-commerce", "enterprise Internet access", and "government Internet access".

Generally speaking, the construction of broadband metropolitan area network is divided into three layers: backbone layer, tandem layer and access layer. To use a metaphor, the backbone layer is equivalent to the highway between cities, the confluence layer is equivalent to the roads in the urban area of the city, and the access layer is to solve the problem of repairing the road from the urban area to the community, and reaching the roads of each household. doorstep. In other words, the construction of the access layer of the broadband metropolitan area network solves what is often called the "last mile" problem.

At present, there are mainly four broadband access technologies put into application in the market:

1. ADSL technology

It is a technology that uses the existing twisted-pair copper cable network to provide broadband access services. The bandwidth and transmission distance of ADSL technology are relatively large obstacles.

Two, CABLE MODEM (cable modem) technology

It is a technology based on fiber-coaxial hybrid network (HFC), which can realize access and access to Internet information within the frequency band that does not affect cable television broadcasting. However, HFC has the problems of two-way transformation and service quality decline after users increase.

3. Wireless Access Technology

Wireless access technology has a relatively independent market space in occasions that are not suitable for wired access. However, the current wireless access technology is not very mature, and is still restricted by standards and practicality. Especially for residential users and large-scale commercial use, it still needs a relatively long process.

4. Ethernet access technology

High-speed Ethernet access has many natural advantages because it can be seamlessly combined with IP network and has excellent scalability. Currently, it is generally welcomed by business users and is rapidly becoming a hot spot for investment by telecom operators. With the improvement of service quality and the development and maturity of billing and management technology, it will gradually enter the home users. Ethernet access technology can provide high-speed Internet access services at a relatively low cost.

At present, the access layer of the broadband metropolitan area network adopts a large number of Ethernet access methods FTTB+LAN with optical fiber and five types of lines, which is the more popular 1000 Mbit to the community, 100 Mbit to the building, and 10 Mbit to the user's Ethernet access method, because this is a new access technology different from the traditional digital subscriber line XDSL and fiber-coaxial hybrid network HFC, can provide users with an access rate of up to 10 megabits to achieve broadband access, So it is widely used.

Because at present, for the vast majority of home users, there is no five-category line or optical fiber pre-arranged in the house, and the penetration rate of cable television coaxial cable in the family is already quite high. Therefore, there are engineering problems in this technology, which will increase the operator's network operation cost and hinder the user's access. This problem is brought about by the Ethernet technology in the access implementation. The following describes in detail the implementation of the Ethernet access in the broadband access of the metropolitan area network.

In the broadband access construction of the metropolitan area network, the Ethernet access technology is used to realize the five types of lines entering the home, as shown in Figure 1. First, the switching equipment of the community node realizes 1000 For megabit connection, a 100-megabit connection is achieved between the cell node equipment and the access equipment of the building through optical fiber or Category 5 lines, and then Category 5 lines are laid in each unit of the building. The scope of laying ranges from residential users to The doorway of the unit, along the corridor of the unit, until the access equipment of the building. Since the laying of the Category 5 line only reaches above the door of the residential user’s house, if the residential user wants to enjoy broadband access, he must drill a hole in the door to introduce the Category 5 line into the home of the resident. devices, such as computers, to connect. With such an access method, for residents who have completed the interior decoration, drilling holes from the door will inevitably damage the interior decoration and affect the user's decorative effect, especially when spending tens of thousands, hundreds of thousands, or hundreds of thousands of luxury It is almost impossible to carry out open-wire installation in the decorated interior.

Invention content:

The purpose of the present invention is to construct a new broadband access system for metropolitan area network, provide a perfect broadband access method for the construction of metropolitan area network, utilize the existing cable TV coaxial cable, do not need a large number of indoor wiring, provide users with It provides a convenient broadband access method, and at the same time saves costs for network operators, which is conducive to quickly developing broadband services, accessing users, and ensuring successful network operation.

A broadband access system for a metropolitan area network proposed by the present invention includes: a cell node device, a building node device, and a user node device; an optical fiber connection is used between the cell node device and the metropolitan area network tandem node device; The optical fiber or the five types of lines used between the node equipment of the residential area and the building node equipment are connected, and the cable TV coaxial cable is used to connect between the node equipment of the building and the user node equipment, and the other end of the user node equipment is connected to A user communication device terminal.

In the metropolitan area network broadband access system of the present invention, due to the use of pre-laid cable TV coaxial cables in the housing construction specification, the broadband access of the metropolitan area network users is completed, and a broadband access rate of 10 megabits is provided. Lay Category 5 lines to enter the home, reduce the engineering quantity of the metropolitan area network construction, save construction investment, adopt the metropolitan area broadband access system of the present invention, do not have any changes to the user's house structure, do not need to drill holes, and do not need to redo the indoor Wiring, protect the user's indoor decoration effect, provide users with the enthusiasm to access the MAN, and promote the development of my country's information construction.

Description of drawings:

The specific embodiment of the present invention will be further described below in conjunction with accompanying drawing

Fig. 1 is the connection diagram of FTTB+LAN (optical fiber to the building plus five types of lines) metropolitan area network broadband access system of prior art;

Fig. 2 is FTTB+CABLE (optical fiber to building adds cable TV coaxial cable line) metropolitan area network broadband access system connection diagram of the present invention;

Figure 3 is a schematic diagram of coaxial cable broadband access for cable TV realized by building node equipment;

Fig. 4 is a schematic diagram of coaxial cable broadband access for cable TV realized by user node equipment;

Fig. 5 is the principle diagram that the present invention realizes the simultaneous transmission of cable television and metropolitan area network data communication;

Detailed ways:

Firstly, it introduces how to use Ethernet access technology to realize broadband access in the access layer of the broadband metropolitan area network. In Figure 1, the connections between devices are identified by A, B, C, and D. A represents 1000 megabits of optical fiber Ethernet, and B, C, and D represent 100 megabits of optical fibers or Category 5 cables. A cell node device can be connected to multiple building node devices. In Figure 1, building node devices 1, 2, ..., N are used to identify building devices by number. Realize 10Mbit broadband access between building node equipment and users through five-category lines, and one building equipment can connect multiple users' PCs. Ethernet access technology has the characteristics of good cost performance, scalability, and easy installation, making it the main means to provide high-speed access for enterprise users. At present, more than 80% of global enterprise users use Ethernet access.

Although the Ethernet access method has many advantages mentioned above, for home users, there are problems in engineering construction and cost in installation. The broadband access system of the present invention adopts the access system FTTB+CABLE (Fiber To The Building+Cable) of optical fiber to the building plus cable TV coaxial cable.

With reference to the FTTB+CABLE metropolitan area network access system of the present invention shown in Fig. 2, the connection E of the metropolitan area network cell node equipment and the building node equipment represents the 100 megabits of optical fiber or five-category line, and B among Fig. 1, C and D have the same connection. F, G, and H represent the cable TV coaxial cable connecting the building node equipment and the user node equipment. One building node equipment can connect multiple user node equipment. In Figure 2, user node equipment 1, 2, ..., M, Identify building equipment by number. The user contact device is connected to the user's TV set through the cable TV coaxial cable, and connected to the user's PC through the five-category line.

This FTTB+CABLE access method considers that most home users already have cable TV coaxial cables in their homes. As long as the cables are properly modified, users can watch cable TV and connect to the metropolitan area network at the same time. data communication.

The principles of the building node device and the cell node device of the MAN broadband access system of the present invention will be described in detail below.

Figure 3 describes the principle of the building node equipment. For the building node equipment, it is connected to the cell node equipment through the Ethernet interface. The data from this interface is sent to the data modulation circuit through the Ethernet interface circuit, and the modulated data signal passes through the cable TV. After driving the circuit, it is sent out from the coaxial cable interface, and then reaches the user node device in the user's home through the transmission of the coaxial cable; on the contrary, the user information received from the coaxial cable interface is sent to the data solution through the cable television coaxial cable receiving circuit. Adjust the circuit, convert it into Ethernet data, pass through the Ethernet interface circuit, and transmit it to the node device of the cell through the Ethernet interface to complete the information interaction.

The principle of user node equipment is described in Figure 4. For user node equipment, the coaxial cable interface is connected to the building node equipment. The modulated data signal received from this interface passes through the coaxial cable receiving circuit and sends the data to the data demodulation circuit. , restored to Ethernet data, and sent to the user's computer, set-top box and other communication equipment through the Ethernet interface circuit. Vice versa, the user's information is reversely processed and sent to the MAN to complete information interaction.

Fig. 5 is the principle diagram that the present invention realizes the simultaneous transmission of cable TV and metropolitan area network data communication, has described the connection figure between building node equipment, user node equipment and cable TV signal in Fig. 5, uses the method for frequency division multiplexing to Realize the simultaneous transmission of broadband data and TV signals on the coaxial cable. The TV signal uses the high-frequency part of the coaxial cable, and the data signal uses the low-frequency part of the coaxial cable after modulation. The high-pass filter is used to realize the high-frequency and low-frequency Separate to ensure non-interference with each other.

The application of the broadband access system of the metropolitan area network of the present invention will be described below by using a cell with M ^* N broadband users as an example.

In the broadband access system of the metropolitan area network of the present invention, the emphasis is on the application of the broadband access technology to complete the broadband data access of the user and provide the user with an access rate of 10 megabits. The system structure is shown in Figure 2. The data metropolitan area tandem node provides 1000 megabit optical fiber access to connect to the node equipment (Ethernet switch) in the community. The Ethernet switch completes the exchange of data information in the community and provides multiple ports. The 100-Mbit Ethernet interface connects multiple building node devices, providing access to N building nodes. The physical medium for connection is optical fiber or Category 5 cable, as shown in Figure 1. The building node devices also provide multiple connection user devices The interface connects the broadband access devices of M users, and the connected physical media share the coaxial cable of cable television. The connection diagram is shown in Figure 2, and the access of M ^* N broadband users can be realized in the community. Since the existing cable TV coaxial cable is used as the connection cable for broadband access, the broadband access mode of FTTB+CABLE can be realized, which can avoid the problems caused by the use of five-category lines to provide broadband access in the mode of FTTB+LAN. In order to solve the problems caused by the existing engineering problems and problems affecting the indoor environment of users, in Figure 3, it introduces the realization principle of building node equipment using coaxial cables to achieve broadband access. The Ethernet data signal sent by the Ethernet switch of the community node is modulated and sent to the coaxial cable of the cable TV for transmission. Network data, connected to user communication equipment, such as computers, set-top boxes, etc., through the Ethernet interface, the processing process of the user node equipment is shown in Figure 4, similarly, the user communication equipment uses the Ethernet interface to connect to the user node equipment, and completes the modulation of the Ethernet data signal After processing, it is sent back to the equipment of the building node through the coaxial cable of cable TV, and after demodulating the modulated signal, the data is sent to the Ethernet switch of the community node through the Ethernet interface to complete the interactive processing of data communication. The frequency division multiplexing technology is used on the cable TV coaxial cable, and the high-pass filter is used to isolate the data signal and the TV signal without interfering with each other. The implementation method is shown in Figure 5. The data signal uses the low-frequency part of the coaxial cable transmission, and the TV signal uses the high-frequency part of the coaxial cable transmission. to complete the construction of the broadband access system of the metropolitan area network.

The metropolitan area network broadband access system of the present invention adopts cable TV coaxial cable transmission from the building to the user section, and does not affect the original service of cable TV, and realizes the household project conveniently, avoiding the use of five-category lines in the user's residence In the process of re-laying the line, the user's broadband access can be completed, and the broadband access service can be provided to the user.

Claims (4)

1. A broadband access system for a metropolitan area network, characterized in that the system includes: a cell node device, a building node device, a user node device; used between the cell node device and the metropolitan area network tandem node device Optical fiber connection, the optical fiber used between the cell node equipment and the building node equipment or the five types of lines are connected, and the cable TV coaxial cable is used between the building node equipment and the user node equipment to connect, and the user node equipment The other end is connected to the user communication equipment terminal. 2. A kind of metropolitan area network broadband access system according to claim 1, is characterized in that, described building node equipment comprises: Ethernet interface, Ethernet interface circuit, data modulation and demodulation circuit, cable television coaxial Cable driving and receiving circuit, coaxial cable interface; the Ethernet interface, Ethernet interface circuit, data modulation and demodulation circuit, cable television coaxial cable driving and receiving circuit, coaxial cable interface are connected in series in sequence, and the Ethernet interface The other end is connected to the cell node equipment, and the other end of the coaxial cable interface is connected to the user node equipment; the data modulation and demodulation circuit modulates the Ethernet data sent by the Ethernet interface circuit into data that can be transmitted in the coaxial cable, and the The data transmitted by the CATV coaxial cable driving and receiving circuit is demodulated into Ethernet data. 3. A kind of metropolitan area network broadband access system according to claim 1, is characterized in that, described user node equipment comprises: coaxial cable interface, cable television coaxial cable driving and receiving circuit, data modulation and demodulation circuit, Ethernet interface circuit, Ethernet interface; the coaxial cable interface, cable TV coaxial cable driving and receiving circuit, data modulation and demodulation circuit, Ethernet interface circuit, Ethernet interface are connected in series in sequence, and the coaxial cable interface The other end of the Ethernet interface is connected to the building node equipment, and the other end of the Ethernet interface is connected to the user communication equipment terminal; the data modulation and demodulation circuit demodulates the data transmitted by the cable TV coaxial cable drive and receiving circuit into Ethernet data, and converts the Ethernet The Ethernet data sent by the network interface circuit is modulated into data that can be transmitted in the coaxial cable. 4. a kind of metropolitan area network broadband access system according to claim 1 is characterized in that, the two ends of the coaxial cable line that uses cable TV from the building node equipment to the user node equipment respectively branch out a port and Connect a high-pass filter, the other end of the high-pass filter close to the building node equipment side is connected to the cable TV signal source, and the other end of the high-pass filter close to the user node equipment side is connected to the cable TV signal interface of the TV terminal.

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