CN105187159A - Decoding method used for grouping and regrouping algebraic exchange engine data packet - Google Patents

Abstract

The invention discloses a decoding method used for grouping and regrouping algebraic exchange engine data packets, which belongs to the technical field of communication and relates to the fields of algebraic exchange and network encoding. The decoding method is a decoding algorithm with a network encoding function in an algebraic exchange engine. The decoding algorithm can recover cells lost in the exchange process through carrying out exclusive-or operation on the cells by utilizing redundant information in the encoding cells. The decoding method of a function of being capable of reducing loss rate of small data packets during the exchange process, thereby achieving the purposes of enhancing network throughput, increasing communication efficiency and the like.

Description

A kind of coding/decoding method for algebraically switching engine packet packet recombining

Technical field

The application relates to communication technical field, refers more particularly to algebraically and exchanges and network code field.

Background technology

Algebraically exchange be a kind of multipath from route switching structure, algebraically distributive lattice theory is applied to from route matrix by this structure, and this structure has completely distributed from route, without advantages such as inner buffer, linear speed and non-jitters.Under guarantee provides the condition of QoS, be applicable to extensive expansion.But this structure can produce internal contention and external blocking, thus result in certain packet loss.In existing algebraically switching system, directly cannot recover for the packet lost, this packet can only be obtained by the mode retransmitted, thus reduce communication efficiency.In order to reduce packet loss, a kind of effective method is merged network code and algebraically switching fabric, utilizes network code to recover the packet lost, thus the packet loss of effective reduction system.

Summary of the invention

The application provides a kind of coding/decoding method for algebraically switching engine packet packet recombining, decoding algorithm in the algebraically switching engine of its coding Network Based, it can utilize coding cell, the cell lost in exchange process is recovered by decoding computing, thus improve the targets such as communication quality, reduce the cost of data re-transmission.

Particularly, the coding/decoding method for algebraically switching engine packet packet recombining that the application provides, comprising:

Parallel cell of data is carried out parallel-serial conversion by buffer memory;

Input state machine carries out header extraction respectively to the cell of data converting serial to, header identification, access address are determined, be stored into assembling buffer memory and packet integrality judges;

Packet integrality judged result is sent to output state machine;

Output state machine is inquired about packet integrality judged result;

Output state machine abandons packet or decodes, exports, and wherein, if judged result is that packet is complete, need not decode; If judged result is lose a cell of data in packet, then decoded the cell of loss by the cell of data after combining remaining cell of data and coding; If judged result is for lose two and two or more cell of data, then directly abandon this packet.

The beneficial effect of the application is:

The application can utilize the redundant information in coding cell, by the XOR to cell, recover the cell lost in exchange process, this decoding function can reduce the Loss Rate of packet in exchange process, thus reach increase network throughput, improve the targets such as communication efficiency.

Accompanying drawing explanation

Fig. 1 is the structural representation of the algebraically switching engine in an embodiment with network code function;

Fig. 2 is the schematic diagram of decoded packet data and restructuring in an embodiment;

Fig. 3 is the process schematic of decoding in an embodiment.

Embodiment

By reference to the accompanying drawings the application is described in further detail below by embodiment.

Please refer to Fig. 1, is the structural representation of the algebraically switching engine of the coding Network Based in the present invention.The IP packet of standard from N number of input port 1.1.1,1.1.2 ..., 1.1.N enters, and in data preprocessing module 1.2, will add synchronous control signal, and packet is cut into the equal data slice of length and adds packet header control information, and wherein N is positive integer.In Fig. 1, the thick arrow 1 of black represents package, i.e. the Ethernet data bag of standard; After packet enters data preprocessing module 1.2, the thick arrow 2 of grey represents the data slice after being cut, i.e. cell; The thin arrow 3 of grey represents Flow Control, i.e. data synchronizing signal.Coding module 1.3 pairs of coding for information element, the redundant information of generation enters post-module with raw data packets.N number of parallel VOQ module 1.4.1,1.4.2 ..., data are shunted according to output port by 1.4.N, packet are sent into algebraically Switching Module 1.5 by certain dispatching algorithm simultaneously.At N number of Knockdown block 1.6.1,1.6.2 ..., in 1.6.N, the cell belonging to same packet is re-assemblied in a certain order, recovers original packet.Only having when a cell loss concealment having been detected in assembling process, just can start N number of decoder module 1.7.1,1.7.2 ..., 1.7.N, recovers the cell of loss by decoding.

The coding method for algebraically switching engine packet packet recombining in the application, comprising:

Parallel cell of data is carried out parallel-serial conversion by buffer memory;

Input state machine carries out header extraction respectively to the cell of data converting serial to, header identification, access address are determined, be stored into assembling buffer memory and packet integrality judges;

Packet integrality judged result is sent to output state machine;

Output state machine is inquired about packet integrality judged result;

Output state machine abandons packet or decodes, exports, and wherein, if judged result is that packet is complete, need not decode; If judged result is lose a cell of data in packet, then decoded the cell of loss by the cell of data after combining remaining cell of data and coding; If judged result is for lose two and two or more cell of data, then directly abandon this packet.

Please refer to Fig. 2, in above process, Knockdown block 1.6.1,1.6.2 ..., in 1.6.N, it comprises two functions: and turn string and assembling output.And a turn string state machine 2.1 is implemented and turns string function, it will exchange the cell of data serialization processed: exchange in gap at first half, by parallel data cell stored in cell buffer memory 2.2, extract header, inspection cell validity, puts into header buffer memory 2.3 simultaneously, exchange in gap at latter half, cell is read in a serial fashion, and adds control signal, send into assembled part together with header buffer memory.

At assembling output, its input state machine carries out header extraction respectively, header identification, access address are determined, stored in operations such as packet header buffer memory 2.4, the judgements of packet integrality, because packet is when being cut into several cells, the identification of data packets word be equipped with to each cell and cell of data identifier word, leave in header.After header extracts, according to the address that identification of data packets word and cell of data identifier word determination cell store.Cell of data is stored in after data pack buffer 2.6, check that whether packet is complete, if complete or imperfect and exceed maximum latency, by packet integrality judged result (comprise complete, packet loss cell but decodable code is recovered, packet loss cell not decodable code recover) be sent to output state machine.

Mainly by exporting, decoder state machine 2.5 realizes to assemble this function, carry out the inquiry of packet complete judgement Structure Receive respectively, get complete packet or abandon or decode, packet exports.If packet is complete, need not decoding, directly sending packet to exporting buffer memory 2.7; If lose a cell in packet, the cell of data of loss can be decoded in conjunction with remaining cell and coding cell; If lose two and two or more, directly abandon this bag and do abnormality processing, and empty memory space.

Decoding is the inverse process of coding, and thinking is as follows:

As shown in Figure 3, Packet1 is made up of N number of cell, a total N+1 cell after coding.If in the process exchanged, the n-th cell loss concealment in Packet1, then start the data that decoder module recovers loss.Decoding algorithm is: Cell_n=Cell_1 ⊕ Cell_2 ⊕ ... ⊕ Cell_n-1 ⊕ Cell_n+1 ⊕ ... ⊕ Cell_N+1.

Finally, export buffer memory the Packet Generation assembled is exported to network interface.

Above content is the further description done the application in conjunction with concrete execution mode, can not assert that the concrete enforcement of the application is confined to these explanations.For the application person of an ordinary skill in the technical field, under the prerequisite not departing from the present application design, some simple deduction or replace can also be made.

Claims (1)

1., for a coding/decoding method for algebraically switching engine packet packet recombining, it is characterized in that, comprising:

Parallel cell of data is carried out parallel-serial conversion by buffer memory;

Input state machine carries out header extraction respectively to the cell of data converting serial to, header identification, access address are determined, be stored into assembling buffer memory and packet integrality judges;

Packet integrality judged result is sent to output state machine;

Output state machine is inquired about packet integrality judged result;

Output state machine abandons packet or decodes, exports, and wherein, if judged result is that packet is complete, need not decode; If judged result is lose a cell of data in packet, then decoded the cell of loss by the cell of data after combining remaining cell of data and coding; If judged result is for lose two and two or more cell of data, then directly abandon this packet.