CN1323511C - Virtual cascade communication method with framing function on quasi-synchronous digital series - Google Patents
Virtual cascade communication method with framing function on quasi-synchronous digital series Download PDFInfo
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Abstract
The present invention relates to a virtual cascade communication method for the frame-separating function performed on quasi-synchronous digital series, which belongs to the technical field of communication and transmission. The method of the present invention defines a virtual cascade mode for classifying data links in a basic frame at the speed of 2048 kbit/s, and the link granularity is further thinned into a passage of 64 kbit/s from the link of 2048 kbit/s. The method supports a maximum differential delay of transmission among data links, which is greater than 128 ms, supports the virtual cascade among the links greater than 256, and keeps a higher utilization ratio of band-width. Short time is needed for frame synchronization of a receiving terminal, and the links working in a passage type virtual cascade mode or a full speed mode absolutely support LCAS. When working in the passage type virtual cascade mode or the full speed mode, all the links can easily communicate with the existing standard virtual cascade equipment.
Description
Technical field
The present invention relates to have on a kind of PDH (Pseudo-synchronous Digital Hierarchy) the virtual cascade communication method of framing function, belong to communication tranmission techniques field.
Background technology
Be accompanied by Internet fast development, IP (hereinafter to be referred as IP) has become the first-selected agreement of integrated services communication, its loaded information amount also is being doubled and redoubled, and how utilizing existing telecommunication resources to set up broadband IP network is the focus of Recent study.At present, the technology of comparative maturity mainly contains IP (hereinafter to be referred as POS) on the synchronous digital hierarchy and the IP (hereinafter to be referred as POA) on the accurate synchronous transfer module.POS wraps IP in the virtual container of the synchronous digital hierarchy of directly packing into, and path overhead is few, realization is simple, has automatic protection switching feature; The multiple connection process more complicated of POA can provide good quality of service to guarantee by high overhead.From present market, the product based on POS/POA has been released in each big communication equipment commercial city, but overall cost is higher, mainly towards be some high-end applications.For the point-to-point communication below tens000000, the advantage of above-mentioned two kinds of technology is also not obvious for bandwidth demand.
The ITU-T of standardization department of international telecommunication union telecommunication in 2004 the standard of its formulation G.7043/Y.1343 in to PDH on the Virtual Concatenation mode of multilink of various speed grade define respectively, make the transfer of data that on PDH, can carry out greater than the basic rate grade, as enhancing, to adapt to the needs of integrated services communication to PDH transmission low-rate data function.Regulation has only same number of frames structure (same speed grade) just can carry out cascade.On the speed of 2048kbit/s, each cyclic redundancy check (CRC) multi-frame (hereinafter to be referred as the CRC multi-frame) (16 basic frames) distributes a virtual concatenation overhead byte.This Virtual Concatenation supports that differential delay maximum between each road is 256ms; Support the Virtual Concatenation of maximum 16 links; Channel maximum bandwidth N*1980kbit/s (N is the number of links of Virtual Concatenation); Channel utilization is about 96.7%; Minimum multi-frame lock in time (finding the time of a multi-frame) is 2ms.This Virtual Concatenation mode support ITU-T standard G.7042/Y.1305 in the definition link capacity dynamically adjust scheme (hereinafter to be referred as LCAS).LCAS can be dynamic and level and smooth the change transmission network in container capacity, simultaneously can when link is made mistakes, unload link automatically, the link of loading reparation automatically when link-recovery.The Virtual Concatenation of ITU-T definition has realized that granularity is the cascade of the link of a speed grade, is example with 2048kbit/s, and it can realize 2N million data channel.But for the business of transmission demand less than 2M speed, such as voice and low-speed data service, the granularity of 2M obviously causes channel utilization not high.
Summary of the invention
The objective of the invention is to propose to have on a kind of PDH (Pseudo-synchronous Digital Hierarchy) the virtual cascade communication method of framing function, use the technology of Virtual Concatenation, at the internal distribution link of the basic frame of PDH, to support big as far as possible link differential delay; Support number of links as much as possible; Bandwidth availability ratio is high as far as possible; Support LCAS; Can communicate with existing standard Virtual Concatenation equipment.
Have the virtual cascade communication method of framing function on the PDH (Pseudo-synchronous Digital Hierarchy) that the present invention proposes, may further comprise the steps:
(1) will be defined as the passage Virtual Concatenation based on the frame structure that PDH goes up the Virtual Concatenation of 2048kbit/s speed grade, three kinds of patterns of passage cascade or full rate, the structure of described passage Virtual Concatenation pattern is: each basic frame is made up of 32 bytes, the 1st byte wherein deposited frame synchronous byte, the content of frame synchronous byte meets the regulation of the G.704 middle CRC of the formation multi-frame of ITU-T standard, 16 basic frames constitute a CRC multi-frame, 16 bytes of same position constitute 1 frame of links in 16 basic frames, per the 1st byte deposited virtual concatenation overhead, all the other 15 byte store data, overhead byte wherein is defined as: with the ITU-T standard G.7043/Y.1343 in multi-frame sign 1 be that high 4 of overhead byte at 14 places are defined as the high 4 of member number, with multi-frame sign 1 is that 4 of member number at 15 places form new member number, all the other contents meet the definition of ITU-T standard in G.7043/Y.1343, the structure of described channel level gang mould formula is: each basic frame is made up of 32 bytes, the 1st byte wherein deposited frame synchronous byte, the N continuous byte that the fixed position of network management system in each basic frame distributed is formed the isl frame of a N*64kbit/s passage, wherein per the 1st byte is the virtual concatenation overhead byte, deposit the time tag of this isl frame, all the other N-1 byte store data, the structure of described full-rate mode is: each basic frame is made up of 32 bytes, the 1st byte wherein deposited frame synchronous byte, the content of frame synchronous byte meets the regulation of the G.704 middle CRC of the formation multi-frame of ITU-T standard, 16 basic frames constitute a CRC multi-frame, wherein the 1st of the 1st basic frame the byte deposited frame synchronous byte, the 2nd byte is virtual concatenation overhead, all the other 30 byte store data, in the 2nd to the 16th the basic frame, the 1st byte deposited frame synchronous byte, all the other 31 byte store data, overhead byte wherein is defined as: with the ITU-T standard G.7043/Y.1343 in multi-frame sign 1 be that high 4 of overhead byte at 14 places are defined as the high 4 of member number, with multi-frame sign 1 is that 4 of member number at 15 places form new member number, and all the other contents meet the definition of ITU-T standard in G.7043/Y.1343;
(2) each bar link of network management system configuration transmitting terminal, it is worked under passage Virtual Concatenation or full rate branch frame pattern, perhaps all links are all worked under channel level gang mould formula, transmitting terminal in the communication system is according to the link of network management system configuration, in above-mentioned frame structure, deposit communication data, fill Virtual Concatenation information in the overhead byte in above-mentioned frame structure;
(3) each bar link of network management system configuration receiving terminal, make it be operated in passage Virtual Concatenation or full rate branch frame pattern, perhaps all links all are operated in channel level gang mould formula, receiving terminal in the communication system is from the link of network management system configuration, recover frame structure, and according to the differential delay between the elimination of the time tag in the Virtual Concatenation information link, member number or the link according to the network management system configuration calls over communication data then;
(4) use the transmitting terminal of described Virtual Concatenation mode to communicate by letter with the realization of standard Virtual Concatenation communication equipment according to the configuration of network management system with receiving terminal.
Transmitting terminal described in this method is deposited the method for communication data in above-mentioned described passage Virtual Concatenation pattern and full-rate mode frame structure, comprise the steps:
(1) according to the ITU-T standard G.704 in to the regulation of CRC multi-frame, in the CRC multi-frame, fill the frame synchronous byte of each basic frame;
(2) fill virtual concatenation overhead in the 1st byte of each frame of every 64kbit/s passage of passage Virtual Concatenation pattern multi-frame, in the 2nd byte of the 1st basic frame of full-rate mode multi-frame, fill virtual concatenation overhead, the expense content meet the ITU-T standard G.7043/Y.1343 in for the definition of virtual concatenation overhead, wherein the member number sum is increased to 256 by 16;
(3) Data Position at frame structure is unit with the byte, in a basic frame time 125us according to member number padding data successively from small to large.
Transmitting terminal described in this method is deposited the method for communication data in described channel level gang mould formula frame structure, comprise the steps:
(1) in first byte of the basic frame that every continuous 32 bytes constitute, inserts frame synchronous byte;
(2) in network management system first byte, insert current time tag,, indicate less than 255 the time when the time as the Virtual Concatenation information of this link for the N continuous byte of this link assignment, its value adds 1, when the time was masked as 255, its value became 0, as the time tag of following frame;
(3) in a basic frame time according to the Data Position of byte interleaving mode in the described channel level gang mould of each bar formula isl frame structure padding data successively.
The method of the receiving terminal reading of data described in this method comprises the steps:
(1) when all 2048kbit/s links were worked under passage Virtual Concatenation pattern or full-rate mode, the method for receiving terminal reading of data comprised the steps:
(a) determine the CRC multi-frame structure according to the frame synchronous byte in the basic frame, from the CRC multi-frame structure, read full-rate mode multi-frame virtual concatenation overhead byte, enter the multi-frame synchronous regime;
(b) each bar 64kbit/s passage of distributing in the passage Virtual Concatenation pattern multi-frame is carried out determining after the frame synchronization structure of each bar link respectively according to the CRC in the virtual concatenation overhead byte, the virtual concatenation overhead byte of difference read-out channel Virtual Concatenation pattern from each passage virtual cascade link structure, enter the isl frame synchronous regime, if detect frame or multiframe out-of-sync., then get back to above-mentioned steps (a);
(c) each the bar link under passage Virtual Concatenation pattern and the full-rate mode is alignd according to separately multi-frame sign 1, and according to member number order from small to large, in each basic frame time, take out data, if frame or multiframe out-of-sync. occur, then get back to above-mentioned steps (a), if OOF appears in link, then get back to above-mentioned steps (b);
(2) when all 2048kbit/s links were worked under channel level gang mould formula, the method for receiving terminal reading of data comprised the steps:
(d) determine channel level gang mould formula frame structure according to the frame synchronous byte in the basic frame, from frame structure, read Virtual Concatenation information in the 1st byte of N byte of network management system configuration, enter frame synchronization state;
(e) each the bar link under the channel level gang mould formula is alignd according to separately time tag, and according to the link order from small to large of network management system configuration, Data Position from each link in each basic frame time takes out data in the mode that byte interleaves, if OOF occurs, then get back to above-mentioned steps (d).
Transmitting terminal described in this method and receiving terminal are realized method for communicating according to the configuration and the standard Virtual Concatenation communication equipment of network management system, comprise the steps:
(1) when the transmitting apparatus in the communication system adopts above-mentioned Virtual Concatenation, receiving equipment to adopt standard Virtual Concatenation mode, all 2048kbit/s links are full-rate mode in the transmitting apparatus of network management system configuration, fill ' 0 ' among the Gao Siwei of member number in the virtual concatenation overhead byte, the Virtual Concatenation of configuration is 1～16 the tunnel;
(2) when the receiving equipment in the communication system adopts above-mentioned Virtual Concatenation, transmitting apparatus to adopt standard Virtual Concatenation mode, fill ' 0 ' in high 4 of virtual concatenation overhead byte multi-frame sign 1 place of network management system configuration transmitting apparatus, the Virtual Concatenation of configuration is 1～16 the tunnel.
The virtual cascade communication method that has framing function on the PDH (Pseudo-synchronous Digital Hierarchy) that the present invention proposes, big at link granularity in the G.7043/Y.1343 middle Virtual Concatenation that defines of ITU-T standard, the problem not high to the low speed data channel utilization, on the 2048kbit/s speed grade, defined a kind of Virtual Concatenation mode, the link granularity has been refined as the 64K passage from 2M in basic frame internal separation data link.Its major advantage comprises:
1, being 256ms for the differential delay that is operated in each the bar data link support maximum under passage Virtual Concatenation pattern or the full-rate mode, is 128ms for the differential delay that is operated in each the bar link support maximum under the channel level gang mould formula;
2, support maximum 256 Virtual Concatenations that are operated in link under passage Virtual Concatenation pattern or the full-rate mode, support infinitely to be operated in the Virtual Concatenation of link under the channel level gang mould formula more;
When 3, all 2048kbit/s links are operated in passage Virtual Concatenation pattern, the channel maximum bandwidth is M*60kbit/s (M is the number of 64kbit/s passage), the channel utilization of 64kbit/s passage is about 93.8%, when each 2048kbit/s link uses whole 31 64kbit/s passages, the total channel utilance is 90.8%: the link bandwidth that is operated under the full-rate mode is K*1980kbit/s (K is the number of complete 2048kbit/s link), and channel utilization is 96.7%.Be operated in passage Virtual Concatenation pattern as M bar 2048kbit/s link, K bar 2048kbit/s link is operated in full-rate mode following time, and total bandwidth is M*60kbit/s+K*1980kbit/s, and channel utilization is between 90.8% and 96.7%.The channel width that is operated under the passage cascade mode of operation is (N-1) * 64kbit/s (N is the number of 64kbi t/s passage), and channel utilization is (N-1)/32.
4, be operated in that minimum multi-frame lock in time (finding a multi-frame) of link is 2ms under passage Virtual Concatenation pattern or the full-rate mode, be 125us the minimum frame lock in time (finding a basic frame) that is operated in link under the channel level gang mould formula;
5, the link that is operated under passage Virtual Concatenation pattern or the full-rate mode is supported fully to LCAS;
6, be operated under passage Virtual Concatenation pattern or the full-rate mode when all links, can realize easily communicating with existing standard Virtual Concatenation equipment.
Description of drawings
Fig. 1 is passage Virtual Concatenation pattern multi-frame structure figure.
Fig. 2 is channel level gang mould formula multi-frame structure figure.
Fig. 3 is full-rate mode multi-frame structure figure.
Fig. 4 is the definition of passage Virtual Concatenation pattern and full-rate mode virtual concatenation overhead byte.
Fig. 5 is that the transmitting terminal data are filled example under passage Virtual Concatenation pattern and the full-rate mode.
Fig. 6 is that the transmitting terminal data are filled example under the channel level gang mould formula.
Embodiment
The virtual cascade communication method that has framing function on the PDH (Pseudo-synchronous Digital Hierarchy) that the present invention proposes comprises that the frame structure that will go up the Virtual Concatenation of 2048kbit/s speed grade based on PDH is defined as passage Virtual Concatenation, passage cascade or three kinds of patterns of full rate; Transmitting terminal in the communication system is deposited communication data according to the link of network management system configuration in above-mentioned frame structure, fill Virtual Concatenation information in the overhead byte in above-mentioned frame structure; Receiving terminal in the communication system recovers frame structure from the link of network management system configuration, and according to the differential delay between the elimination of the time tag in the Virtual Concatenation information link, member number or the link according to the network management system configuration calls over communication data then; Use the transmitting terminal of described Virtual Concatenation mode to communicate by letter with the realization of standard Virtual Concatenation communication equipment according to the configuration of network management system with receiving terminal.
The present invention has defined the frame structure of going up the Virtual Concatenation of 2048kbit/s speed grade based on PDH, is divided into passage Virtual Concatenation, passage cascade or three kinds of patterns of full rate, and every 2048kbit/s data link is used wherein a kind of transmission mode.The data channel of passage Virtual Concatenation pattern and two kinds of transmission modes of full-rate mode can exist in communication process simultaneously, also can only have wherein a kind of pattern, and channel level gang mould formula can only occur separately, can not use with other two kinds of mode mixture.The transmission mode of every 2048kbit/s link is configured by network management system, the notice receiving-transmitting sides.The data channel granularity is 64kbit/s under the passage Virtual Concatenation pattern, and the data channel granularity is (N-1) * 64kbit/s (N is the number of 64kbit/s link) under the channel level gang mould formula.
The passage Virtual Concatenation pattern multi-frame structure of the present invention's definition as shown in Figure 1.It is to do change on the basis of CRC multi-frame of definition in the ITU-T standard in G.704.Each basic frame is made up of 32 bytes, the 1st byte wherein deposited frame synchronous byte, the content of frame synchronous byte meets the regulation of the G.704 middle CRC of the formation multi-frame of ITU-T standard, 16 basic frames constitute a CRC multi-frame, and wherein the 2nd of first basic frame the byte no longer deposited the multi-frame virtual concatenation overhead.In each basic frame except that the 1st byte as the frame synchronous byte, all the other 31 bytes constitute the data link (for example CHl representative data link 1) of 31 64kbit/s.For every data link, 16 bytes of same position constitute 1 frame of links in 16 basic frames, wherein the 1st byte deposited virtual concatenation overhead (for example 01 overhead byte of representing article one link multi-frame), all the other 15 byte store data (D (m n) represents n byte data of m bar link) for example.
The channel level gang mould formula multi-frame structure of the present invention's definition as shown in Figure 2.Each basic frame is made up of 32 bytes, and the 1st byte wherein deposited frame alignment word, and its content meets ITU-T standard regulation G.704.The N continuous byte that the fixed position of network management system in each basic frame distributed is formed the isl frame of a N*64kbit/s passage, and wherein per the 1st byte is the virtual concatenation overhead byte, deposits the time tag of this isl frame, all the other 15 byte store data.Network management system that shown in Figure 2 is is configured to the situation of an isl frame with 5-14 byte in the basic frame, and what the 5th byte deposited is Virtual Concatenation information, and 6-14 byte deposited the data (Dn represents n data byte) of 9 bytes.
The full-rate mode multi-frame structure of the present invention's definition as shown in Figure 3.Each basic frame is made up of 32 bytes, the 1st byte wherein deposited frame synchronous byte, the content of frame synchronous byte meets the regulation of the G.704 middle CRC of the formation multi-frame of ITU-T standard, 16 basic frames constitute a CRC multi-frame, the 2nd byte (byte of this frame synchronous byte back) that defines the 1st basic frame is virtual concatenation overhead, all the other byte store data.The the 2nd to 16 basic frame store data (for example Dn represents n data byte) all except that the 1st byte.
The passage Virtual Concatenation of the present invention's definition and the overhead byte in the full-rate mode are as shown in Figure 4, be (seeing the asterisk place) with the G.7043/Y.1343 middle overhead byte difference that defines of ITU-T standard, high 4 (being to keep the position originally) of the overhead byte of MFI1=14 was defined as the high 4 of member number (hereinafter to be referred as SQ), form new SQ, so just can carry out Virtual Concatenation for 4 with the SQ at original MFI1=15 place 256 links.The reason of doing like this is just to contain 31 64kbit/s passages in every 2048kbit/s link, has exceeded the scope that the standard Virtual Concatenation can be represented (16).In the overhead byte implication of each field and fill rule and ITU-T G.7043/Y.1343 in definition identical, so just can support fully, and differential delay, minimum multi-frame are also identical with the standard Virtual Concatenation lock in time to LCAS.
The transmitting terminal framing is the process of an inverse multiplexing in the communication system that the present invention proposes, and its method is as follows:
When (1) all 2048kbit/s links were operated in passage Virtual Concatenation pattern or full-rate mode, the frame synchronous byte filling mode of each basic frame and the ITU-T standard CRC multi-frame in G.704 was consistent in the multi-frame.Each frame of every 64kbit/s passage of passage Virtual Concatenation pattern multi-frame all will be filled the virtual concatenation overhead byte in (comprising 16 bytes), and every link is equivalent to independently data path, has overhead byte separately.The 2nd byte of the 1st basic frame of full-rate mode multi-frame filled the virtual concatenation overhead byte.The overhead byte content of two kinds of patterns is increased to 256 (8bits) by 16 (4bits) except that the SQ scope, and is consistent with the filling mode of ITU-T standard in G.7043/Y.1343.Data are that unit fills with the byte, and (125us) fills from small to large according to SQ in a basic frame time length, and the data that need to send out earlier are filled in the less link of SQ.The data byte of a full-rate mode multi-frame has identical SQ.For example, for the data channel of distributing SQ, data Data1, Data2 ... the filling mode of Data64 as shown in Figure 5.Wherein passage 1 is operated under the passage Virtual Concatenation pattern, and passage 2 is operated under the full-rate mode.
When (2) all 2048kbit/s links are operated in channel level gang mould formula, in first byte of the basic frame that every continuous 32 bytes constitute, insert frame alignment word; In network management system first byte, insert current time tag (1 byte) for a N continuous byte of this link assignment, Virtual Concatenation information as this link, then when time sign less than 255 the time, its value adds 1, when the time is masked as 255, it is 0 that its value becomes, as the time tag of following frame; The Data Position of the mode that interleaves according to byte in a basic frame time (125us) in each bar isl frame structure be padding data successively.For example, for the data channel of distributing, data Data1, Data2 ... the filling mode of Data10 as shown in Figure 5.Wherein passage 1 and passage 2 all are operated under the channel level gang mould formula.
The method to receiving terminal restore data in the communication system that the present invention proposes is as follows:
(1) step of receiving terminal restore data is as follows when all 2048kbit/s links are operated in passage Virtual Concatenation pattern or full-rate mode:
(i) determine the CRC multi-frame structure according to the frame synchronous byte in the basic frame, from the CRC multi-frame structure, read full-rate mode multi-frame virtual concatenation overhead byte, enter the multi-frame synchronous regime;
(ii) each bar 64kbit/s passage of distributing in the passage Virtual Concatenation pattern multi-frame is carried out determining after the frame synchronization structure of each bar link respectively according to the CRC in the virtual concatenation overhead byte, the virtual concatenation overhead byte of difference read-out channel Virtual Concatenation pattern from each passage virtual cascade link structure, enter the isl frame synchronous regime, if detect frame or multiframe out-of-sync., then get back to above-mentioned steps (i);
(iii) each the bar link under passage Virtual Concatenation pattern and the full-rate mode is alignd according to separately multi-frame sign 1, and according to member number order from small to large, in each basic frame time, take out data, the data byte of a full-rate mode multi-frame should take out continuously owing to have identical SQ.If frame or multiframe out-of-sync. occur, then get back to above-mentioned steps (i), if OOF appears in link, then get back to above-mentioned steps (ii).
(2) step of receiving terminal restore data is as follows when all 2048kbit/s links are operated in channel level gang mould formula:
(i) determine channel level gang mould formula frame structure according to the frame synchronous byte in the basic frame, from frame structure, read Virtual Concatenation information in the 1st byte of N byte of network management system configuration, enter frame synchronization state;
(ii) each the bar link under the channel level gang mould formula is alignd according to separately time tag, and according to the link order from small to large of network management system configuration, Data Position from each link in each basic frame time takes out data in the mode that byte interleaves, if OOF occurs, then get back to above-mentioned steps (i).
The present invention proposes, and that 64kbit/s passage in the passage Virtual Concatenation pattern multi-frame is carried out the frame synchronization step is as follows: the receiving terminal calculated in advance goes out the CRC content in the multi-frame overhead byte of each link, and the CRC computational methods are according to the definition of ITU-T standard in G.7042/Y.1305.The CRC content is fixed for every link.Under asynchronous regime, do not handle the virtual concatenation overhead byte, then enter synchronous regime in correct position probing to the CRC content of calculated in advance continuous 3 times.If every link all enters synchronous regime, then carry out above-mentioned steps (3).For every link, 1 CRC content false occurs in synchronous regime and then enter plesiochronous mode.At plesiochronous mode, do not read new overhead byte, the processing of data is carried out according to a last configuration, if next CRC mistake then enter desynchronizing state, otherwise would get back to synchronous regime.
Use the method for communication equipment and standard Virtual Concatenation communication apparatus communication as follows:
(1) when the transmitting apparatus in the communication system adopts above-mentioned Virtual Concatenation, receiving equipment to adopt standard Virtual Concatenation mode, all 2048kbit/s links are full-rate mode in the network management system configuration transmitting apparatus, fill ' 0 ' among the Gao Siwei of member number in the virtual concatenation overhead byte, the Virtual Concatenation of configuration is 1～16 the tunnel;
(2) when the receiving equipment in the communication system adopts above-mentioned Virtual Concatenation, transmitting apparatus to adopt standard Virtual Concatenation mode, fill ' 0 ' in high 4 of virtual concatenation overhead byte multi-frame sign 1 place of network management system configuration transmitting apparatus, the Virtual Concatenation of configuration is 1～16 the tunnel.
At network cross connection node place, can not change data fill order and content in passage cascade channel and the full rate passage, but can freely exchange route the data under minute frame pattern.This route for network provides the flexible processing mode.
Do not use at communication process under the situation of channel level gang mould formula, on the Virtual Concatenation mode basis that the present invention proposes during exploitation LCAS function, the state machine of the use of LCAS control word and system receiving-transmitting sides all with G.7042/Y.1305 middle stipulate consistent of ITU-T standard.Because the frame structure of two kinds of patterns that the present invention proposes can use simultaneously, the system that makes carries out can changing when link capacity is dynamically adjusted some 64kbit/s passages (configuration branch frame pattern link), also can change some 2048kbit/s links (configuration full-rate mode link), the application that in fact this expanded LCAS makes the data link that they can two kinds of capacity of dynamic-configuration.
Claims (5)
1, the virtual cascade communication method that has framing function on a kind of PDH (Pseudo-synchronous Digital Hierarchy) is characterized in that this method may further comprise the steps:
(1) will be defined as passage Virtual Concatenation, passage cascade or three kinds of patterns of full rate based on the frame structure that PDH goes up the Virtual Concatenation of 2048kbit/s speed grade,
The structure of wherein said passage Virtual Concatenation pattern is: each basic frame is made up of 32 bytes, the 1st byte wherein deposited frame synchronous byte, the content of frame synchronous byte meets the regulation of the G.704 middle CRC of the formation multi-frame of ITU-T standard, 16 basic frames constitute a CRC multi-frame, 16 bytes of same position constitute 1 frame of links in 16 basic frames, per the 1st byte deposited virtual concatenation overhead, all the other 15 byte store data, overhead byte wherein is defined as: with the ITU-T standard G.7043/Y.1343 in multi-frame sign 1 be that high 4 of overhead byte at 14 places are defined as the high 4 of member number, with multi-frame sign 1 is that 4 of member number at 15 places form new member number, and all the other contents meet the definition of ITU-T standard in G.7043/Y.1343;
The structure of described channel level gang mould formula is: each basic frame is made up of 32 bytes, the 1st byte wherein deposited frame synchronous byte, the N continuous byte that the fixed position of network management system in each basic frame distributed is formed the isl frame of a N*64kbit/s passage, wherein per the 1st byte is the virtual concatenation overhead byte, deposit the time tag of this isl frame, all the other N-1 byte store data;
The structure of described full-rate mode is: each basic frame is made up of 32 bytes, the 1st byte wherein deposited frame synchronous byte, the content of frame synchronous byte meets the regulation of the G.704 middle CRC of the formation multi-frame of ITU-T standard, 16 basic frames constitute a CRC multi-frame, wherein the 1st of the 1st basic frame the byte deposited frame synchronous byte, the 2nd byte is virtual concatenation overhead, all the other 30 byte store data, in the 2nd to the 16th the basic frame, the 1st byte deposited frame synchronous byte, all the other 31 byte store data, overhead byte wherein is defined as: with the ITU-T standard G.7043/Y.1343 in multi-frame sign 1 be that high 4 of overhead byte at 14 places are defined as the high 4 of member number, with multi-frame sign 1 is that 4 of member number at 15 places form new member number, and all the other contents meet the definition of ITU-T standard in G.7043/Y.1343;
(2) each bar link of network management system configuration transmitting terminal, it is worked under passage Virtual Concatenation or full rate branch frame pattern, perhaps all links are all worked under channel level gang mould formula, transmitting terminal in the communication system is according to the link of network management system configuration, in above-mentioned frame structure, deposit communication data, fill Virtual Concatenation information in the overhead byte in above-mentioned frame structure;
(3) each bar link of network management system configuration receiving terminal, make it be operated in passage Virtual Concatenation or full rate branch frame pattern, perhaps all links all are operated in channel level gang mould formula, receiving terminal in the communication system is from the link of network management system configuration, recover frame structure, and according to the differential delay between the elimination of the time tag in the Virtual Concatenation information link, member number or the link according to the network management system configuration calls over communication data then;
(4) use the transmitting terminal of described Virtual Concatenation mode to communicate by letter with the realization of standard Virtual Concatenation communication equipment according to the configuration of network management system with receiving terminal.
2, the method for claim 1 is characterized in that wherein said transmitting terminal deposits the method for communication data in above-mentioned described passage Virtual Concatenation pattern and full-rate mode frame structure, comprises the steps:
(1) according to the ITU-T standard G.704 in to the regulation of CRC multi-frame, in the CRC multi-frame, fill the frame synchronous byte of each basic frame;
(2) fill virtual concatenation overhead in the 1st byte of each frame of every 64kbit/s passage of passage Virtual Concatenation pattern multi-frame, in the 2nd byte of the 1st basic frame of full-rate mode multi-frame, fill virtual concatenation overhead, the expense content meet the ITU-T standard G.7043/Y.1343 in for the definition of virtual concatenation overhead, wherein the member number sum is increased to 256 by 16;
(3) Data Position at frame structure is unit with the byte, in a basic frame time 125us according to member number padding data successively from small to large.
3, the method for claim 1 is characterized in that wherein said transmitting terminal deposits the method for communication data in described channel level gang mould formula frame structure, comprises the steps:
(1) in first byte of the basic frame that every continuous 32 bytes constitute, inserts frame synchronous byte;
(2) in network management system first byte, insert current time tag,, indicate less than 255 the time when the time as the Virtual Concatenation information of this link for the N continuous byte of this link assignment, its value adds 1, when the time was masked as 255, its value became 0, as the time tag of following frame;
(3) in a basic frame time according to the Data Position of byte interleaving mode in the described channel level gang mould of each bar formula isl frame structure padding data successively.
4, the method for claim 1 is characterized in that the method for wherein said receiving terminal reading of data comprises the steps:
(1) when all 2048kbit/s links were worked under passage Virtual Concatenation pattern or full-rate mode, the method for receiving terminal reading of data comprised the steps:
(a) determine the CRC multi-frame structure according to the frame synchronous byte in the basic frame, from the CRC multi-frame structure, read full-rate mode multi-frame virtual concatenation overhead byte, enter the multi-frame synchronous regime;
(b) each bar 64kbit/s passage of distributing in the passage Virtual Concatenation pattern multi-frame is carried out determining after the frame synchronization structure of each bar link respectively according to the CRC in the virtual concatenation overhead byte, the virtual concatenation overhead byte of difference read-out channel Virtual Concatenation pattern from each passage virtual cascade link structure, enter the isl frame synchronous regime, if detect frame or multiframe out-of-sync., then get back to above-mentioned steps (a);
(c) each the bar link under passage Virtual Concatenation pattern and the full-rate mode is alignd according to separately multi-frame sign 1, and according to member number order from small to large, in each basic frame time, take out data, if frame or multiframe out-of-sync. occur, then get back to above-mentioned steps (a), if OOF appears in link, then get back to above-mentioned steps (b);
(2) when all 2048kbit/s links were worked under channel level gang mould formula, the method for receiving terminal reading of data comprised the steps:
(d) determine channel level gang mould formula frame structure according to the frame synchronous byte in the basic frame, from frame structure, read Virtual Concatenation information in the 1st byte of N byte of network management system configuration, enter frame synchronization state;
(e) each the bar link under the channel level gang mould formula is alignd according to separately time tag, and according to the link order from small to large of network management system configuration, Data Position from each link in each basic frame time takes out data in the mode that byte interleaves, if OOF occurs, then get back to above-mentioned steps (d).
5, the method for claim 1 is characterized in that wherein said transmitting terminal and receiving terminal configuration and the standard Virtual Concatenation communication equipment realization method for communicating according to network management system, comprises the steps:
(1) when the transmitting apparatus in the communication system adopts above-mentioned Virtual Concatenation, receiving equipment to adopt standard Virtual Concatenation mode, all 2048kbit/s links are full-rate mode in the transmitting apparatus of network management system configuration, fill ' 0 ' among the Gao Siwei of member number in the virtual concatenation overhead byte, the Virtual Concatenation of configuration is 1～16 the tunnel;
(2) when the receiving equipment in the communication system adopts above-mentioned Virtual Concatenation, transmitting apparatus to adopt standard Virtual Concatenation mode, fill ' 0 ' in high 4 of virtual concatenation overhead byte multi-frame sign 1 place of network management system configuration transmitting apparatus, the Virtual Concatenation of configuration is 1～16 the tunnel.
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| CNB2005100534669A CN1323511C (en) | 2005-03-11 | 2005-03-11 | Virtual cascade communication method with framing function on quasi-synchronous digital series |
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| CN101005327B (en) * | 2006-01-17 | 2011-12-07 | 中兴通讯股份有限公司 | Regulating device and method for dynamic link capacity and flow of transmission net loaded ethernet |
| CN102223207B (en) * | 2011-06-18 | 2014-04-16 | 安徽省菲特科技股份有限公司 | Base band lossless switching method and base band lossless switching device based on regeneration section (RS) frame structure |
| CN114466087B (en) * | 2022-02-21 | 2023-05-30 | 重庆奥普泰通信技术有限公司 | Data transmission method, device, equipment and storage medium |
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| CN1094877A (en) * | 1992-10-09 | 1994-11-09 | Gpt有限公司 | Improvement about telecommunication transmission systems |
| CN1223510A (en) * | 1997-09-12 | 1999-07-21 | 阿尔卡塔尔公司 | Method for transmitting data packets and network element for carrying out the method |
| US6041055A (en) * | 1994-03-25 | 2000-03-21 | Marconi Communications Limited | Multipurpose synchronous switch architecture |
| EP1274191A1 (en) * | 2001-07-02 | 2003-01-08 | Alcatel | Method and apparatus for obtaining a scalable and managed bandwidth for connections between asynchronous level and synchronous hierarchy level in a telecommunication network |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1094877A (en) * | 1992-10-09 | 1994-11-09 | Gpt有限公司 | Improvement about telecommunication transmission systems |
| US6041055A (en) * | 1994-03-25 | 2000-03-21 | Marconi Communications Limited | Multipurpose synchronous switch architecture |
| CN1223510A (en) * | 1997-09-12 | 1999-07-21 | 阿尔卡塔尔公司 | Method for transmitting data packets and network element for carrying out the method |
| EP1274191A1 (en) * | 2001-07-02 | 2003-01-08 | Alcatel | Method and apparatus for obtaining a scalable and managed bandwidth for connections between asynchronous level and synchronous hierarchy level in a telecommunication network |
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