CN103391641B - Cable broadband is wireless stretch system - Google Patents

Abstract

The present invention relates to the wireless stretch system of cable broadband, it is made up of WiFi base station and CPE two parts, contacted by wireless communication mode between WiFi base station and CPE, it is characterized in that: WiFi base station mainly includes 802.11b/g module, MAC? Bridge module, DPP module, UPM module, PCF module, OAM module, DBW and DBU module, L2SPW and L2SPU module, MGU module, three sets are by 802.11b/g module, MAC? Bridge module, DPP module, UPM module, PCF module, the circuit of OAM module composition connects DBW module by DPP module and connects DBU module by UPM module, DBW module connects PMD and PMA by L2SPW module, PMD and PMA connects DBU module by L2SPU module, POWER provides power supply to above-mentioned module.

Description

Cable broadband is wireless stretch system

Technical field:

The present invention relates to a kind of wireless stretch system of cable broadband.

Background technology

On January 16th, 2004, the Ministry of Information Industry issues " notice about carrying out Village Interconnection Project pilot work in part provinces and regions ", from then on pulls open communication " Rural areas " engineering construction prelude. In Eleventh Five-Year Plan, communication " Rural areas " engineering construction is determined with " Rural areas phone, can surf the Net in every country " for construction object, communication " Rural areas " engineering construction is pushed to a new high. But eventually because of factor impacts such as access technology means are poor, rural area network based living environment severe, networking investment is big, communication " Rural areas " engineering construction is made slow progress, all unrealized government planning target in various places. In " 12 " plan, finally it is to be emphasized again that farmer communication infrastructure construction will be strengthened, promote Option of Rural Information Service ability, advance communication basic public services equalization.

Urban residents are sparsely populated, apart from each other, but large number of, big for this cable consumption, and engineering cost is high. It addition, rural area network based living environment is severe, cable transmission, apart from limited, needs more active equipment in Rural Broadband network, this will result directly in network failure rates and network operation expense is climbed to a higher point. Therefore, no matter select which kind of traditional access technology (xDSL, LAN, CableModem) to carry out construction of rural broadband network, all suffer from problems. About 400000, China administrative village, about 3,000,000, unincorporated village. Along with rural economy is fast-developing, Rural Broadband access demand can quickly increase. How quick, convenient, low cost rural area computer is accessed the Internet, provide information service for urban residents.

Summary of the invention

In order to overcome drawbacks described above, it is an object of the invention to provide a kind of wireless stretch system of cable broadband.

To achieve these goals, the present invention adopts the following technical scheme that

Cable broadband is wireless stretch system, it is made up of WiFi base station and CPE two parts, is contacted by wireless communication mode between WiFi base station and CPE.

WiFi base station mainly includes 802.11b/g module, MACBridge module, DPP module, UPM module, PCF module, OAM module, DBW and DBU module, L2SPW and L2SPU module, MGU module, the circuit that three sets are made up of 802.11b/g module, MACBridge module, DPP module, UPM module, PCF module, OAM module connects DBW module by DPP module and connects DBU module by UPM module, DBW module connects PMD and PMA by L2SPW module, PMD and PMA connects DBU module by L2SPU module, and POWER provides power supply to above-mentioned module.

CPE is a kind of bridge, is used for connecting cable network and wireless network. CPE provides a user with broadband inserting service by the LAN interface of UNI side; By wireless WiFi base station that customer service bridged to. Cpe device associates upper WiFi base station by monitoring Beacon frame. CPE is in subordinate location in the wireless stretch system of cable broadband, accepts the mandate of WiFi base station, sends data in authorized window, to avoid conflict.

The WiFi base station of the present invention comprises three groups of IEEE802.11b/g unit, is effectively increased system whole volume, reduces network design cost; Enhancement mode media access control sublayer, effectively reduces collision probability; Efficient SDRAM dispatching algorithm.

Accompanying drawing explanation

Fig. 1 is the WiFi architecture of base station schematic diagram of the present invention.

Fig. 2 is DPP modular structure schematic diagram.

Fig. 3 is UPM modular structure schematic diagram.

Fig. 4 is DBW and DBU module overall structure.

Fig. 5 is L2SPW and L2SPU module overall structure.

Fig. 6 is PCF module overall structure.

Detailed description of the invention

Further illustrate below in conjunction with accompanying drawing:

A kind of wireless stretch system of cable broadband, it is made up of WiFi base station and CPE two parts, is contacted by wireless communication mode between WiFi base station and CPE. as shown in Figure 1, WiFi base station mainly includes 802.11b/g module, MACBridge module, DPP module, UPM module, PCF module, OAM module, DBW and DBU module, L2SPW and L2SPU module, MGU module, three sets are by 802.11b/g module, MACBridge module, DPP module, UPM module, PCF module, the circuit of OAM module composition connects DBW module by DPP module and connects DBU module by UPM module, DBW module connects PMD and PMA by L2SPW module, PMD and PMA connects DBU module by L2SPU module, POWER provides power supply to above-mentioned module.

Each module is as described below:

(1) 802.11b/g module

This module mainly completes two parts function, the first MAC layer management control function, its two be PHY layer management control function.

MAC layer is responsible for the communication between STA, for instance the functions such as scanning, certification, access, encryption, roaming, synchronization and data transmission. And the message between STA includes Frame, control frame and management frame three types. Frame is the various application messages of user, for instance mail, WEB browse, video flowing and voice flow etc. Control frame is for assisting the transmission of Frame, to reduce data collision probability. Control frame includes RTS, CTS and ACK three types. It is mutual that management frame is responsible for the ability between STA, the management work such as certification, association. Management frame includes Beacon, Probe, Authentication and Association.

The same with Ethernet, 802.11 adopt csma (carriersensemultipleaccess is called for short CSMA) mechanism to control the access to transmission medium. But, conflict (collisions) can waste the transfer resource of preciousness, and therefore 802.11 transfer to use conflict avoidance (CSMA/CA) machine-processed, and collision detection (CSMA/CD) mechanism practiced by non-usage Ethernet.

Physical layer is divided into two sublayers, i.e. physical layer Aggregation sublayer (PhysicalLayerConvergenceProcedure is called for short PLCP) and physical medium associated sub-layer (PhysicalMediumDependent is called for short PMD). The function of PLCP is to gather frame and aerial passed radio wave from MAC layer. PLCP simultaneously can for the frame frame head plus oneself, for instance: lead code.But, the lead code that every kind of modulation system adopts all differs. Each position that PMD is responsible for transmitting PLCP utilizes antenna to be sent in the air.

(2) MACBridge module

This module completes the conversion between 802.11 frames and 802.3 frames. 802.11 frame is as follows to the conversion logic of 802.3 frames:

��, when receiving point and receiving a frame, first can detect the integrity that this frame is basic. It follows that access point for the physical layer used, can verify the check code (PCS) of frame.

After �� verifies that frame reception is errorless, access point continues to check whether process this frame further.

��, once access point judges whether to process this frame further, just needs first to its deciphering (see the need of).

After �� deciphering, access point checks whether this frame is frame fragment, if need restructuring further.

�� judges that this frame is the need of bridge joint, if needed, carries out frame conversion.

After �� frame format converts 802.3 to, FCS to be recalculated.

The new frame of generation is given subsequent module for processing by ��.

802.3 frame to the conversion logic of 802.11 frames is the inverse process of said process.

(3) DPP module

This module completes downstream packets classification feature. DPP is responsible for distinguishing DATA frame, PCF frame and OAM frame from downlink data. Wherein data frame classification has following manner: based on MAC Address, based on COS, based on VLANID, based on IP address etc. DPP module overall structure is illustrated in fig. 2 shown below.

CLASSIFY module is that the frame received carries out frame classification, and distinguishing Frame is PCF frame, OAM frame or Frame. If Frame, also want the effective information of further analysis frame, for instance:

The priority of �� present frame;

�� VLAN tag;

�� frame type;

Whether �� frame comprises IGMP packet;

�󡣡���

Fifo module is that the frame received is carried out buffer memory.

(4) UPM module

The up multiplexing select permeability of this resume module frame, it may be assumed that be transmitted according to certain priority. Wherein, the priority of PCF frame is the highest, and OAM frame priority is taken second place, and Frame priority is minimum. When sending, always preferentially PCF frame is sent, then OAM frame is sent, finally send Frame. The form of this module processed frames is identical with the frame format involved by DPP module. UPM module overall structure is illustrated in fig. 3 shown below.

VPCF module receives the PCF frame that PCF module sends over, and is respectively stored in the FIFO of inside modules, and higher level's module by signal after arriving sends PCF frame.

VOAM module receives the OAM frame that OAM module sends over, and is respectively stored in the FIFO of inside modules, and higher level's module by signal after arriving sends OAM frame.

VDBU module receives the Frame that DBU module sends over, and is respectively stored in the FIFO of inside modules, and higher level's module by signal after arriving sends OAM frame.

The enable signal allowing up transmission that fifo module sends over according to PCF module, selects frame to send according to priority, and PCF frame priority is the highest, OAM takes second place, and Frame priority is minimum.

(5) DBW and DBU module

DBW module is responsible for the downlink data frame of three groups of radio-cells of buffer memory, and the priority according to frame sends data. DBU functions of modules and DBW are just contrary. DBW and DBU module overall structure is illustrated in fig. 4 shown below.

DBWWR module receives the Frame sended over and by its buffer memory to SDRAM from DPP module. DBWRD module, according to upper layer module signal designation, is taken out Frame from SDRAM, is then sent to upper layer module, namely completes the descending transmission of data.

DBUWR module receives the Frame after upstream data processes, needing to continue up data frame buffer memory in SDRAM. Receive upper layer module need send data instruction after, from SDRAM take out data, carry out up transmission.

(6) L2SPW and L2SPU module

L2SPW and L2SPU module completes two layer functions such as VLAN process and speed limit process. L2SPW and L2SPU module overall structure is illustrated in fig. 5 shown below.

The judgement the need of speed limit frame that LR module provides according to DPP module, uses token bucket algorithm to carry out speed limit process the frame of each priority, and gives follow-up data processing module the Frame after speed limit.

VLAN module supports two kinds of VLAN patterns, i.e. transparent transmission and TAG pattern. Under transparent transmission mode, transceiving data is left intact, and directly forwards. Under TAG pattern, at up direction, if receiving the data containing TAG, then directly abandon; If receiving the data not having TAG, then forward after stamping TAG.

(7) PCF module

PFC module is responsible for discovery and the registration of terminal, and responsible quene state reports, and is responsible for local clock and synchronizes, and is responsible for authorizing frame process etc. PCF module overall structure is illustrated in fig. 6 shown below.

VDPP completes the classification to the PCF frame received, i.e. GATE frame, DISCOVERY frame and PAUSE frame, and is passed to subsequent treatment module.

Base station sends GATE message to each CPE and sends authorization message to distribute it, including the time started authorized and length of window, thus indirectly controlling the up transmission of CPE. When the local enumerator of CPE is identical with the time started in GATE message, CPE begins to up transmission. CPE to extrapolate the time of actual transmission data and leave enough surpluses, thus ensureing release wireless link before the interval authorized is finished. GATE module mainly completes to authorize transmission and the response of frame.

Discovery feature completes the various functions of cpe end, including the extraction to the response of REGISTER frame and log-on message, is responsible for framing and the transmission of REGISTER_REQ frame and REGISTER_ACK frame simultaneously. Discovery feature helps CPE to achieve " plug and play " function, when, after CPE powered-down, base station will no longer authorize to CPE distribution; After CPE powers on, utilize and find that frame finds unregistered CPE, and CPE is registered. For completing discovery procedure, first base station to determine that one finds window, namely determines that a special period allows the CPE not registering and having service send the registration request of oneself. And this time started finding window and persistent period are sent to each CPE with the form of broadcast, after CPE receives discovery window message, carry out resolving and sending registration information in discovery window.

The effect of PAUSE module is when base station queue exceedes critical, broadcasts PAUSE frame, it is desirable to each CPE postpones the transmission of data.

SETTIME module is responsible for generation signal lock in time and broadcasts.

(8) OAM module

Being responsible for carrying various management information, by this module, access point can remotely manage each terminal, for instance: terminal configures, terminal software upgrading, Terminal Alert information reporting etc.

(9) MGU module

Radio management, MAC bridge, bag classification, point-to-point emulation, operation management maintainance, two layer services process MGU module and are responsible for the functions such as equipment configuration, management, alarm, are responsible for coordinating three groups of radio-cell synchronizing functions.

CPE is a kind of bridge, is used for connecting cable network and wireless network. CPE provides a user with broadband inserting service by the LAN interface of UNI side;By wireless WiFi base station that customer service bridged to. Cpe device associates upper WiFi base station by monitoring Beacon frame. CPE is in subordinate location in the wireless stretch system of cable broadband, accepts the mandate of WiFi base station, sends data in authorized window, to avoid conflict.

Claims (4)

1. the wireless stretch system of cable broadband, it is made up of WiFi base station and CPE two parts, is contacted by wireless communication mode between WiFi base station and CPE, it is characterised in that:

WiFi base station mainly includes 802.11b/g module, MACBridge module, DPP module, UPM module, PCF module, OAM module, DBW and DBU module, L2SPW and L2SPU module, MGU module, three groups by 802.11b/g module, MACBridge module, DPP module, UPM module, PCF module, the radio-cell of OAM module composition connects DBW module by DPP module and connects DBU module by UPM module, DBW module connects PMD and PMA by L2SPW module, PMD and PMA connects DBU module by L2SPU module, POWER provides power supply to above-mentioned module, CLASSIFY module in DPP module is that the frame received is carried out frame classification, distinguishing Frame is PCF frame, OAM frame or Frame, described 802.11b/g module includes MAC layer management and controls function and PHY layer management control function, described MACBridge module has been the module of conversion between 802.11 frames and 802.3 frames, described DPP module has been the module of downstream packets classification feature, described UPM module is the module of the up multiplexing select permeability processing frame, described PCF module is the module sending PCF frame, and described OAM module is the module sending OAM frame, described DBW module is responsible for the downlink data frame of three groups of radio-cells of buffer memory, and the priority according to frame sends data, and DBU module is responsible for receiving L2SPU data, and the priority according to frame sends Frame to three groups radio-cell, L2SPW and L2SPU module completes VLAN and processes and speed limit process function, described MGU module is responsible for equipment configuration, management, alarm function, is responsible for coordinating three groups of radio-cell synchronizing functions.

2. the wireless stretch system of cable broadband according to claim 1, it is characterized in that: described UPM module includes VPCF module, VOAM module, VDBU module and fifo module, VPCF module receives the PCF frame that PCF module sends over, and it being respectively stored in the fifo module of inside modules, higher level's module by signal after arriving sends PCF frame;

VOAM module receives the OAM frame that OAM module sends over, and is respectively stored in the fifo module of inside modules, and higher level's module by signal after arriving sends OAM frame;

VDBU module receives the Frame that DBU module sends over, and is respectively stored in the fifo module of inside modules, and higher level's module by signal after arriving sends Frame;

The enable signal allowing up transmission that fifo module sends over according to PCF module, selects frame to send according to priority, and PCF frame priority is the highest, OAM takes second place, and Frame priority is minimum.

3. the wireless stretch system of cable broadband according to claim 1, it is characterized in that: DBW module includes DBWWR module and DBWRD module, DBU module includes DBUWR module and DBURD module, and DBWWR module receives the Frame sended over and by its buffer memory to SDRAM from DPP module;

DBWRD module, according to upper layer module signal designation, is taken out Frame from SDRAM, is then sent to upper layer module, namely completes the descending transmission of data;

DBUWR module receives the Frame after upstream data processes, needing to continue up data frame buffer memory in SDRAM; Receive upper layer module need send data instruction after, from SDRAM take out data, carry out up transmission.

4. the wireless stretch system of cable broadband according to claim 1, it is characterized in that: L2SPW and L2SPU module includes LR module, VLAN module, the judgement the need of speed limit frame that LR module provides according to DPP module, use token bucket algorithm to carry out speed limit process the frame of each priority, and give follow-up data processing module the Frame after speed limit;

VLAN module supports two kinds of VLAN patterns, i.e. transparent transmission and TAG pattern; Under transparent transmission mode, transceiving data is left intact, and directly forwards; Under TAG pattern, at up direction, if receiving the data containing TAG, then directly abandon; If receiving the data not having TAG, then forward after stamping TAG.