CN100407717C - Very high bit rate digital user line link rate switching method - Google Patents

The present invention relates to a high bit rate digital user line (VDSL) link rate switching method. In the method, a VDSL link rate is divided into a plurality of steps from small rate to large rate according to a usable range, and an upstream rate and a downstream rate which are easy to establish a chain are selected from each step to be combined into a schema. When the switching method is used, a link state is detected at certain time; if chain breaking is detected, local-end configuration is changed into a basic schema; if a chain can be established in the basic schema by links, the local-end configuration and the far-end configuration of the links are simultaneously in a maximum rate schema; if the chain can be established in the maximum rate schema by links, the chain is established in the basic schema, and the local-end configuration and the far-end configuration of the links are simultaneously in a schema which is one step lower than the maximum rate schema; the schema orderly descends until the chain is established in a schema. The method has the advantages of automatically detecting and switching the rate of the VDSL links, enhancing the flexibility and the reliability of a system, greatly reducing maintenance work, and reducing maintenance cost.

Very high bit rate digital user line link rate switching method

Technical field

The present invention relates to data communication technology, more particularly, relate to a kind of very high bit rate digital user line link rate switching method that is used for the Digital Subscriber Line connecting system.

Background technology

VDSL (Very high data rate Digital Subscriber Line), be called very high bit rate digital subscriber line again, from technical standpoint, VDSL can be considered the next generation of ADSL (Asymmetric DigitalSubscriber Line, i.e. ADSL Technology).In short distance, the speed that it provides on a pair of plain old telephone twisted-pair feeder substantially exceeds the speed of ADSL.In addition, with Ethernet (LAN) access way, traditional dial-up access mode etc. relatively, VDSL has advantageous winning part.

The VDSL access device of using much adopts QAM (Quadature Ampli-tudeModulation at present, be quadrature amplitude modulation) debud mode, 10baseS nest plate as Siemens, it can reach 1,000,000 to twenties000000 symmetry or asymmetric line speed by frequency range and constellation parameter are set.The 10bsesS nest plate provides corresponding passage in the VDSL link, can make the CPU that is positioned at local side not only can monitoring be set to proximal device, under the situation of VDSL link setup, also can the VDSLmodem of far-end be provided with and monitor.But in circuit situation variation and take place to decrease under the disconnected situation, the VDSL link can't be by setting the speed link setup, and this will cause user's chain rupture and the catastrophe failure that can't surf the Net.Need this moment the attendant to arrive field diagnostic and safeguard, owing to can't also can occur the situation that needs the user to cooperate sometimes to far-end modem monitoring under the chain rupture situation.These problems have increased the weight of the maintenance work of VDSL equipment, are unfavorable for the application and the popularization of VDSL equipment.

Summary of the invention

The technical problem to be solved in the present invention is, at in the prior art by the caused maintenance issues of fixed rate VDSL link, a kind of very high bit rate digital user line link rate switching method is provided, adapts to, solve the problem of safeguarding inconvenience with the automatic adjusting that realizes the VDSL link rate.

The present invention can be achieved through the following technical solutions, at first the VDSL link rate is divided into ascending a plurality of shelves by its usable range, selecting in each grade, a kind of up-downgoing speed of easy link setup is combined as a kind of pattern, that is to say that the described pattern representative of each grade is a kind of by setting the up-downgoing speed combination that parameter values such as up-downgoing frequency range, constellation value, interpolation are realized.Wherein the highest one grade is the maximum rate pattern that can reach the maximum rate combination.Described VDSL link also can be at link setup under the basic mode formula (being deep low gear), and this is that a speed is lower, but the combination of reliable and stable speed.

During normal the operation, described VDSL link is link setup under the maximum rate pattern that can reach the maximum rate combination; And when described VDSL link chain rupture, its far-end modulator-demodulator can be made as oneself the basic mode formula, and this moment is if the local side of VDSL link also is set to the basic mode formula, then the VDSL link can be under the basic mode formula be the link setup state from the chain rupture recovering state.The present invention just is being based on this point, when abnormal running, carries out speed according to the following steps and switches:

(1), regularly detect Link State, if detect chain rupture, then the local side configuration with described VDSL link changes the basic mode formula corresponding with the far-end modulator-demodulator into;

(2), detect whether link setup under the basic mode formula of described VDSL link, if then the local side configuration of described VDSL link and far-end configuration are made as simultaneously and can reach the maximum rate pattern that maximum rate makes up;

(3), detect whether link setup under set pattern of described VDSL link, as can not link setup, then change the local side configuration of described VDSL link into the basic mode formula corresponding once more with the far-end modulator-demodulator;

(4), detect whether link setup under the basic mode formula of described VDSL link, if then the local side configuration of described VDSL link and far-end configuration are made as simultaneously the pattern of hanging down a grade than set pattern of last time;

(5), repeating said steps (3) and (4), until described VDSL link link setup under a certain pattern between maximum rate pattern, maximum rate pattern and the basic mode formula or basic mode formula.

According to method of the present invention, in described step (2) and (4), if described VDSL link is failed link setup under the basic mode formula, represent that then link also can't link setup under the basic mode formula, may be because the modulator-demodulator of remote subscriber not be opened or link decreases disconnected fully, need artificial the intervention this moment, system does not deal with.

In the VDSL link, adopt method of the present invention, the speed of VDSL link automatically can detect and automatically switch, make described VDSL link can be under a certain pattern between maximum rate pattern, maximum rate pattern and the basic mode formula or basic mode formula link setup, the flexibility and the reliability of system have been improved, make system applies convenient simultaneously, alleviate maintenance work greatly, reduced maintenance cost.

The invention will be further described below in conjunction with drawings and Examples.

Description of drawings

Fig. 1 is the flow chart that the VDSL link rate detects switching automatically among the present invention.

Embodiment

In a preferred embodiment of the invention, the VDSL link rate is divided into ascending n shelves by its usable range, n kind pattern is correspondingly arranged.

Step 1: regularly detect Link State;

Step 8: the local side configuration and the far-end configuration of VDSL link are made as pattern k simultaneously, if trial then is flank speed pattern k=n for the first time, if attempt for the second time, are pattern k=n-1 then, and the rest may be inferred;

Step 11: express possibility because the modulator-demodulator of remote subscriber is not opened or link decreases disconnectedly fully, need artificial the intervention this moment, system does not deal with.