KR100323765B1 - Method for realinzing ATM signaling of Neywork Interface Equipment in LMDS System - Google Patents

Abstract

Local Multipoint Distribution Service (hereinafter referred to as LMDS) system, especially in LMDS system where LMDS system performs ATM signal processing effectively in order to reduce load of headend device in LMDS system. The present invention relates to a method for implementing ATM signal processing of a device, and includes a protocol for wireless media control (MAC), a protocol for defining an interface between a user and a network, and a network interface. In a network access device having a MAC control unit capable of controlling a subscriber modem and having an allocation function for the ATM signal processing and a radio channel area setting function between the subscriber and the headend device and a database for the subscriber, Directly requesting channel allocation from a network access device; Verifying authentication of one subscriber modem; if the network access device confirms whether the subscriber modem is authenticated, assigning a channel to the corresponding subscriber modem by the MAC control unit; and the plurality of subscriber modems and the network. ATM data is transmitted through a channel allocated by the signal processing procedure between access devices.

Description

Implementation method of ATM signal processing of network access device in LMS system {Method for realinzing ATM signaling of Neywork Interface Equipment in LMDS System}

The present invention relates to an LMDS system, and more particularly, to a method for implementing ATM signal processing of a network access device in an LMDS system in which the network access device effectively performs ATM signal processing to reduce the load on the headend device in the LMDS system.

In general, due to the development of wireless communication technology and the development of the millimeter wave band, a broadband wireless subscriber network (B-WLL), which is advantageous in terms of ease of network construction, scalability, and economics, is in the spotlight.

In order to realize the broadband wireless subscriber network (B-WLL), Korea announced the frequency in the 20 GHz band, and similar systems include the Canada's Local Multipoint Communication System (LMCS) and the US Regional Multipoint. Distributed Services (LMDS) and ATM Wireless Access (AWA) in Japan are being studied.

Standardization in relation to broadband wireless subscriber networks (B-WLL) is most prominent in the work of the Digital Audio Visual Council (abbreviated as DAVIC).

DAVIC publishes the 1.0 specification up to the 1.3 specification and presents the only specific standard for the broadband wireless subscriber network (B-WLL). DAVIC mentions down time division multiplexing (TDM), up time division multiple access (TDMA) multiple access schemes, and downlink, uplink frame structure, and media access control protocol. have.

In Korea, Ministry of Information and Communication Announcement No. 1997-49 specifies the frequency for the subscriber line of the broadband wireless subscriber network (B-WLL), which allocates 2 ㎓ down to 25.5 ㎓ to 27.5 에서 for bidirectional broadband service in the 20 ㎓ band. Upwardly, 500 MHz of 24.25 Hz to 24.75 Hz was allocated. Of these, the 800 MHz band of 26.7 GHz to 27.5 GHz was temporarily designated for cable television (CATV) transmission.

As such, ultra-high-speed broadband multimedia service using subscriber line frequency in the millimeter wave band (2MHz downwards 25.5㎓-27.5㎓ and 500MHz upwards 24.25㎓24.75㎓) for subscribers within a radius of about 2-5km. An LMDS system that provides is a system developed to deliver multi-channel TV programs to subscribers as a competition for wirelines in the cable television market.

Initially mainly used for cable TV distribution, it gradually developed into a two-way digital system, and the services that a system of two-way high-speed wireless communication concept can provide include voice telephone service, data communication service, interactive video service, voice / data / There are multimedia services and dedicated line services that combine video, and have subscriber types such as general public network subscribers, private network subscribers, and public network transmission relays.

In addition, MMDS, a broadband wireless subscriber network that provides wireless cable television service or high-speed Internet service using subscriber line frequencies in the millimeter wave band (2.535 GHz to 2.655 GHz) for subscribers within a radius of about 30 to 50 km. Standards are also presented in the DVIC 1.3 specification.

1 is a block diagram showing a general LMDS system configuration.

Referring to FIG. 1, the LMDS system may be broadly classified into a service provider 100 and a customer premises equipment unit (CPE) 200.

First, the service provider 100 includes a central office unit (COU) 110, a head-end unit 12, and a hub outdoor unit (HOU) 130. The subscriber unit (CPE) 200 is classified into a home subscriber unit 21 and an office subscriber unit 220.

The central office device (COU) 110 may appropriately multiplex the program and service contents supplied from each program provider, that is, the digital data stream through the network access device 111, thereby providing a headend device ( Head-end unit) 120.

The network connection device 111 performs a function of routing and multiplexing / demultiplexing the data streams transmitted from the ATM switch 113, the telephone switch 112, and the digital line access switch (DACS) 114.

ATM switch 113 is connected to the Internet (Internet) and the transmission control protocol / Internet Protocol (TCP / IP) to provide ATM-LAN service to the subscriber device (CPE) 200, the ATM cell structure data Analyze and exchange the data with the network connection device 111 by configuring the data in the form of a frame that can accommodate 44.736 Mbps digital signal level (DS-3) or 155.52 Mbps synchronous transmission mode (STM-1). Do this.

The telephone exchange 112 performs a function of establishing a mutual communication path when connecting to the PSTN, and accepts the V 5.2 protocol and is connected to the network connection device 111.

The DACS 114 converts the data transmitted from the leased line into a digital signal level (DS-1E) of 2.048 Mbps, a digital signal level (DS-3) of 44.736 Mbps, or a synchronous transmission mode of 155.52 Mbps. It is configured in the form of a frame that can accommodate the STM-1) and performs a function to deliver to the network connection device (111).

In addition, the central office unit (COU) 110 is provided with a network management unit 117 responsible for network management of the entire system, the integrated network management control station 116, and the billing processing unit 115 in charge of the subscriber billing; have.

The network management device 117 and the integrated network management control station 116 are in charge of all operations, state management, and information management of the subscriber device (CPE) 200 through information exchange with the network connection device 111. It is also responsible for network connection and state management between the network connection device 111 and the base station device 130.

To this end, a simple network management protocol (SNMP) / common management information protocol (CMIP) is used between the network access device 111 and the network management device 117. Network status data is received from 111 to perform network management. The same protocol is used between the network management device 117 and the integrated network management control station 116.

The billing processing unit 115 performs a task regarding billing of the subscriber by using centralized automatic message accounting (CDMA).

The head-end device 120 modulates the downstream data of the ATM cell structure transmitted from the network access device 111 to the base station device 130 and transmits the data to the base station device 130. The demodulated upstream data is demodulated and transmitted to the network access device 111.

The base station apparatus 130 amplifies and frequency-converts the downstream data transmitted from the head-end unit 120 and transmits it to the subscriber through a high-directional antenna, and the upstream data received through the radio section. Amplifies and converts the frequency to the head-end unit (120).

Sending and receiving downlink and upstream data of the millimeter wave band (2 GHz of 25.5 GHz to 27.5 GHz and 500 MHz of 24.25 GHz to 24.75 GHz) through the wireless section with the service provider 100 described above. The subscriber device (CPE) 200 may be classified into a home subscriber device 210 for home use and an office subscriber device 220 for office use.

The home subscriber station 210 has peripherals such as a TV, a telephone, a personal computer, and slightly differently, the office subscriber unit 220 has a small capacity private automatic branch exchange (PABX) to support voice services. It has a router for data service.

The home subscriber station (210) is an outdoor unit (ODU: Outdoor Unit) 211 which is installed outdoors due to communication with the service provider 100, a network interface unit (NIU) and a set-top unit (STU) installed indoors. The indoor unit (IDU: Indoor Unit 212) including a set-top unit, and the office subscriber unit 220 also includes an outdoor unit (DOU) 221 and an indoor unit (IDU) 222. do.

The interface formed between the network interface unit (NIU) and the set-top unit (STU) included in the home subscriber unit 21 and the office subscriber unit 220 is an electrical system of a large integrated microprocessor (LSI) for protocol processing of ATM. It is based on the universal interface UTOPIA (UTOPIA: Universal Test & Operation PHY iNTERFACE FOR ATM).

In addition, each outdoor unit (ODU) 211 and 221 of the home subscriber station 210 and the office subscriber station 220 converts and amplifies downstream data inputted through a high-directional antenna to a network interface unit (NIU). Alternatively, frequency conversion and amplification of upstream data transmitted from a network interface device (NIU) is transmitted through a high-directional antenna to a wireless section.

The network interface device (NIU) provided in the indoor unit (IDU) of each subscriber device (210,220) interfaces with the outdoor unit (ODU) 211,221 and the peripheral devices which are a plurality of data terminals. STU) provides peripheral devices with communication functions such as video server, reception and exchange of video signal, and data communication service support function.

In addition, the office subscriber device 220 may be provided with a local area network server (LAN Server) for a plurality of clients (Client) that wants a local area network service (LAN), Ethernet (Ethernet) through a local area network server (LAN Server) ) Can be used.

As mentioned above, the DAVIC specification of the LMDS system and the specification of the system developer did not provide a description and description of ATM signal processing of the network access device.

In particular, due to the technical protection barriers of developed countries, LMDS technical matters are not disclosed. Therefore, no implementation method for ATM signal processing of the LMDS system network access device is mentioned.

The present invention has been made to solve the above problems, and in order to reduce the load of the headend device in the LMDS system, when there is no switching in the headend device and does not allocate dynamic resources, the network access device allocates the radio channel allocation and the ATM. An object of the present invention is to provide a method for implementing ATM signal processing of a network access device to perform signal processing for a network.

In the LMDS system according to the present invention for achieving the above object, a method for implementing ATM signal processing of a network access apparatus has a protocol for wireless medium control (MAC), a protocol defining an interface between a user and a network, and an interface between the networks. It has a MAC controller that can control the subscriber modem by giving MAC command to signal processing of the signal processing device, and allocates the ATM signal processing and sets up the wireless channel area between the subscriber and the headend device and database of the subscriber. In a network access device having a plurality of subscriber modems, requesting channel assignment directly to the network access device, verifying the authentication of the subscriber modem requesting the channel assignment, and the network access device for the subscriber modem If the authentication is confirmed, the MAC control unit allocates a channel to the corresponding subscriber modem. And transmitting ATM data through a channel allocated by the signal processing procedure between the plurality of subscriber modems and the network access device.

1 is a block diagram showing a general LMDS system configuration.

Figure 2 is a block diagram showing the configuration of a network connection device in the LMDS system according to the present invention.

3 is a diagram illustrating an ATM signal processing procedure of a network access apparatus according to the present invention.

4 is a diagram illustrating a protocol stack configuration of an LMDS system according to the present invention.

300: network connection device 400: head end device

301 to 306: connection module 323: division and assembly unit (SAR)

350: ATM signal processing device 370: call processing device

371: MAC control unit 380: network management access device

390: management layer 500, 510: subscriber modem

Hereinafter, a preferred embodiment of an AYM signal processing implementation method of a network access device in an LMDS system according to the present invention will be described with reference to the accompanying drawings.

Figure 2 is a block diagram showing the configuration of the network connection device in the LMDS system according to the present invention.

In general, the network access device plays a role of appropriately multiplexing the program and service contents supplied from each program provider, that is, the digital datastream, to the head-end unit. .

In addition, the network access device performs a function of routing and multiplexing / demultiplexing data streams transmitted from an ATM switch, a telephone switch, and a digital circuit access switch (DACS).

To this end, the network connection device is provided with a plurality of connection modules (301 to 306) for connecting to each exchange.

3 is a diagram illustrating an ATM signal processing procedure of a network access apparatus according to the present invention.

2 and 3, the ATM signal processing procedure in the network connection device 300 will be described.

As shown in FIG. 3, the headend device 400 may or may not have a switching function for ATM signal processing.

When the headend device 400 has a switching function, a virtual channel connection (VCC) function between the subscriber modems 500 and 510 may be provided. However, as in the present invention, when there is no switching function, the network connection device 300 directly controls the subscriber modems 500 and 510, and the headend device 400 has only assembling function.

Accordingly, a procedure of controlling the subscriber station 500 or 501 directly by performing the ATM signal processing by the network access device 300 will be described below.

The network connection device 300 basically includes a call processing function by the call processing device 370, a signal processing function by the ATM signal processing device 350, and a usage parameter control device (UPC) 323. It performs a call control function, an operation management function and a resource management function by the management layer 390 having an operation management apparatus (OAM) 391.

The network connection device 300 receives each signal from the plurality of exchanges to the connection modules 301 to 306, finds the frame synchronization from each of the received bit strings, and extracts the flow path load. In addition, by generating a frame to be transmitted, the payload is mapped (mapping).

The ATM switch 322 switches ATM cells, and the usage parameter controller (UPC) 323 is networked from deliberate operation as well as accidental malfunctions that may affect the quality of service for these calls for already established call connections. To protect the resources, it detects violations of negotiated parameters and performs appropriate control.

The ATM signal processing apparatus 350 is for user-to-network interface (UNI) and network-to-network interface (NNI), and is fixed in the form of a fixed virtual connection (PVC) or switched virtual connection (SVC). ATM services such as Constant Bit Rate, Variable Bit Rate, Unspecified Bit Rate, and Available Bit Rate are provided.

In this case, the MAC control unit 371 is provided in the call processing apparatus 370 to directly control the subscriber modems 500 and 510 without passing through the network connection apparatus 400.

The MAC control unit 371 can directly control the subscriber modems 500 and 510 by giving a MAC control command to the signal processing of the ATM signal processing apparatus 350.

Accordingly, since the network access device 300 has an allocation for signal processing, a radio channel area setting function between the subscriber and the headend device 400, and a database for the subscriber, the system implementation is easy.

Meanwhile, in the headend device 400, a local identifier (LI: Local Identifier) and a virtual path identifier / Virtual Channel Identifier (VPI / VCI) that distinguish each subscriber station and distinguish various applications in each subscriber station Identifiers will be fixed.

Here, the virtual connection to the virtual path identifier / virtual channel identifier (VPI / VCI) corresponding to each local identifier (LI) has a property thereof and is not changed.

Accordingly, the role of the MAC in the headend device 400 is to simply transmit the information about the timeslot to the subscriber modems 500 and 510 with the timeslot assigned by the MAC controller 371 of the network access device 300. will be.

The ATM signal processing procedure according to the present invention is as follows.

When a request for channel allocation is received from the subscriber modems 500 and 510 to the headend device 400, the headend device 400 passes transparently and finally the request signal is transmitted to the network access device 300.

The network access device 300 undergoes an authentication operation through a user database to confirm whether the subscriber who transmitted the request signal is an authenticated subscriber.

If the subscriber is not authenticated, an error message is sent to the subscriber who has requested the channel assignment, and if the subscriber is an authenticated subscriber, the MAC controller 371 allocates the channel to the subscriber. The protocol stack configuration according now is shown in FIG. 4.

4 is a diagram illustrating a protocol stack configuration of an LMDS system according to the present invention.

Referring to FIG. 4, the protocol stack for supporting the PSTN service according to the present invention is composed of the following layers, and the rules for the physical layer and the wireless interval are described in detail in the DAVIC Recommendation. Focused on the selection and implementation of processing protocols.

"ATM" is an ATM layer that processes all information through the physical layer in fixed-length cell units of 53 bytes.

"AAL" is an ATM adaptation layer that enables services to be provided to higher-level applications according to their characteristics, such as voice, video, and data.

This ATM adaptation layer is a layer that coordinates 48-byte user information uniformly handled in ATM cells to match data units of various upper applications.

"SAAL" is an ATM adaptation layer for signal processing in a digital switching system.

"ATM-PHY" is a physical layer for transmitting ATM cells, and the physical layer transmission medium for this is specified in I.432, an I series of the ITU-T standard.

"UNI" is a User-Nework Interface protocol layer that defines the interface between the user side and the network side. This layer follows the provisions of the Recommendation Series ITU-T Q Series on Digital Signaling and Common Line Signaling, including ITU-T Q.2931 and UNI 4.0 as recommended by the ATM Forum.

"NNI" is a network-network interface protocol layer that defines an interface for interworking between several networks. This layer, like the "UNI", is also in accordance with the provisions of the Recommended Series ITU-T Q Series on Digital Signal Exchange and Common Line Signaling, including ITU-T Q.2761 to Q.2764.

"LMDS PHY" is an LMDS physical layer that defines a wireless transmission medium. It follows the DAVIC specification and is now available up to version 1.4.

"LMDS MAC" is the LMDS-MAC protocol layer with wireless media control, which differs from the DAVIC specification and is up to GSUWO version 4.0.

"LAN-PHY" is a LAN protocol physical layer that defines LAN transmission media. This layer controls network access and traffic by using IEEE 802.3, which is an Ethernet standard, and Token Passing. IEEE 802.4, the standard for bus networks, and IEEE 802.5, the standard for other LAN protocols.

"LAN-MAC is a LAN-MAC protocol layer with LAN media control, which is also defined in IEEE 802.3, IEEE 802.4, and IEEE 802.5.

In the protocol stack for the Internet service composed of such layers, a user plane-D for transmitting user data and a B-WLL MAC message are transmitted. It consists of three planes: a user plan-S for the user plane and a control plane for the signal processing.

In particular, in the present invention, the protocol stack of the head-end unit 640 simply takes the role of transmitting ATM cells, and the network access device 630 includes the "LMDS MAC" layer and the "UNI" and " NNI "layer is present.

As described above, according to the ATM signal processing implementation method of the LMDS system of the present invention, since the ATM signal processing is processed only in the network connection device, the overhead of the head-end unit can be reduced.

In addition, since the ATM signal processing is not performed in the head-end unit, the entire system can be easily implemented.

Claims (3)

It has a protocol for barge medium control (MAC), a protocol defining the interface between a user and a network, and a network interface.It has a MAC control unit that can control a subscriber modem by giving MAC commands to signal processing of an ATM signal processing device. In a network access device having an allocation for the ATM signal processing and a radio channel region setting function between a subscriber and a headend device and a database of a subscriber, A plurality of subscriber modems requesting channel assignment directly to the network access device; Verifying authentication of the subscriber modem requesting the channel allocation; Assigning, by the MAC controller, a channel to the corresponding subscriber modem when the network access device determines whether the subscriber modem is authenticated; And transmitting ATM data through a channel allocated by the signal processing procedure between the plurality of subscriber modems and the network access device. The method of claim 1, wherein in the authentication step, if the subscriber modem requesting the channel allocation is not authenticated, an error message is transmitted to the corresponding subscriber modem to inform that the channel cannot be allocated. Implementation method of ATM signal processing in network access device. The method of claim 1, wherein the network connection device performs the signal processing procedure, the head-end device provided in the LMDS system performs an aggregation function for the user data transmitted through the wireless medium. A method for implementing ATM signal processing of a network access device in an LMDS system.