CN101150876B

CN101150876B - A method and device for realizing 1000M passive optical network carrier time division multiplexing service

Info

Publication number: CN101150876B
Application number: CN2006101161932A
Authority: CN
Inventors: 王岱; 周惠琼
Original assignee: Alcatel Lucent Shanghai Bell Co Ltd
Current assignee: Nokia Shanghai Bell Co Ltd
Priority date: 2006-09-19
Filing date: 2006-09-19
Publication date: 2011-01-12
Anticipated expiration: 2026-09-19
Also published as: CN101150876A

Abstract

The invention provids a method for bearing the time division multiplexing service by a kilomega passive optical network and the device thereof, the method includes following steps: a) grouped processing the TDM circuit service; b) generating a controling field which is used to transmit and control in the GPON for the grouped processed TDM grouping data; c) packaging GEM frames by the kilomega passive optical network packaging method, and mapping the TDM grouping data and the controling field to the GEM frame payload area. The invention provides simple and effect TDM service transmitted in the GPON, supports the transmission control management of the TDM service.

Description

A kind of 1000 M passive optical network carrier time division multiplexing service implementation method and device thereof

Technical field

The present invention relates to communication technical field, relate in particular to TDM (time division multiplexing) professional method for packing and device thereof among a kind of GPON (Gigabit Passive Optical Network) at GEM (kilomega passive optical network packaging method) frame.

Background technology

In recent years, fundamentally realized the broadband of " last kilometer " based on the broadband access network of DSL (Digital Subscriber Line).Yet, along with the development and the broadband access coverage of multimedia service constantly enlarges, and consider that following user's bandwidth demand, existing DSL can only be a kind of transition schemes based on copper cash, fundamentally do not solve the following bandwidth problem that inserts.

FTTx (Optical Access Network) will be a kind of final form of broadband access network development, it is with the place, position of optical network unit (ONU), be divided into FTTH (fiber-to-the-home front yard), FTTB (Fiber To The Building), FTTP (FTTP) and FTTC several situations such as (Fiber To The Curb), general designation FTTx.For dwelling house or building, connect the user with optical fiber and mainly contain dual mode: a kind of is directly to connect each family or building with optical fiber; Another kind is to adopt PON (EPON) technology, with optical splitter light signal is carried out branch, and an optical fiber provides service for a plurality of users.

PON technology in the market mainly is divided into APON/BPON (asynchronous transfer mode EPON/broadband passive optical network), EPON (Ethernet passive optical network) and GPON (Gigabit-capable Passive Optical Network).

APON is developed and standardization at first, ITU-TG.982, the ITU-T of ITU-T (portion of international telecommunication union telecommunication) issue G.983.1 and ITU-T standardized content about APON has been described in G.983.3.Yet business is adaptive among the APON provides very complicated, and professional providing capability is limited, and data transfer rate and efficient are not high, and cost is higher.

EPON is proposed by EFM (the first mile Ethernet) research group that IEEE (U.S.'s electronic motor Ssociety of engineers) 802.3 working groups set up in 2000, because do not fully take into account the immutability of speech business, its ability of transmitting traditional TDM business is under suspicion.

The GPON technology is the development of APON, is G.984.x defined by ITU-T, supports full-service, comprises TDM business (for example: speech, PDH and SONET/SDH), Ethernet service, ATM business etc.Therefore, GPON uses than much lower in the past cost traditional voice service is provided when introducing the Ethernet new business of high bandwidth more, is had an optimistic view of by industry.

Fig. 1 has embodied the Typical Disposition and the function when supporting that TDM is professional of GPON network.As shown in the figure, an OLT (optical line terminal) 10 is connected to three ONU (optical network unit) 12a, 12b, 12c by an optical branching device 11.GPON is in Ethernet (Ethernet) data service of carrying from IP network 14, also support the transmission of TDM business, from PSTN network 13 the TDM business between OLT10 and ONU 12b, transmit, the TDM business interface type of OLT10 correspondence is DS3/E3; The TDM business interface type of ONU12b correspondence is T1/E1.

GPON is in the transmission mode of supporting based on the cell of handling the ATM service, also support the transmission mode of GEM frame, TDM business grouping data after handling through packing and Ethernet grouped data are mapped in the GTC frame and in GPON after by the GEM encapsulation process again and transmit.

With the GPON protocol stack structure among the OLT/ONU shown in Figure 2 transmission mode based on the GEM frame among the GPON is described further below, it comprises: protocol layer 22, be used for and upper-layer service interface GTC (GPON Transmission Convergence) layer 21, the frame that transmits from protocol layer is multiplexed with the GTC frame, so that transmit this multiplexing frame; And GPM (the GPON physical medium is relevant) layer 20, to the agreement of GPON system light sending and receiving signal instructions (power output, eye pattern etc.).

Protocol layer 22 comprises GEM client 221, optical network unit management control interface (OMCI) 222, physical layer operations management maintenance module (PLOAM) 223.Wherein, GEM client 221 upwards provides the miscellaneous service that comprises TDM business interface.

GTC layer 21 comprises two sublayers: the adaptive sublayer 212 of GTC framing sublayer 211 and TC.The function that mainly finish GTC framing sublayer 211 has: 1) the multiplexing and demultiplexing of GTC frame, and PLOAM and GEM client portion are multiplexed in the descending GTC frame according to the boundary information of frame head indication, and can be according to the frame head indication from the up each several part that extracts; 2) the GTC frame head generates and decoding, and the GTC frame head of downlink frame generates according to call format, and the frame head of uplink frame can be decoded.The adaptive sublayer 212 of TC provides 2 TC adapters, i.e. GEM TC adapter 212A and OMCI adapter 212B.GEM TC adapter 212A generates the PDU (protocol Data Unit) from GTC framing each GEM client of sublayer, and these PDU are mapped to each GEM client.Adapter provides the GEM interface to upper layer entity: GEM TC adapter transmits interface through frame being fitted to different frames after disposing.OMCI adapter 212B receives data and is sent to the OMCI entity from GEM TC adapter 212A, and it also can be sent to GEM TC adapter to the OMCI solid data on the other hand.

Fig. 3 is a conventional structure of supporting the GEM frame of TDM business and Ethernet service, and it comprises GEM frame head 30 and GEM Payload 31 two parts: GEM frame head 30 is made up of PLI (payload length indication) 301, PortID (port label) 302, PTI (payload type indication) 303 and HEC (the wrong control of head) 304.PLI 301 is the payload section length of unit indication frame head back with the byte, and it can be used for searching next frame head so that demarcation to be provided; PortID 302 is commonly used to provide 4096 different traffic stream identifier among the PON, and multiplexing to realize Business Stream, each PortID comprises a user and transmits stream; PTI 303 is used to the content type and the corresponding processing mode of the section of indication payload; HEC 304 provides the EDC error detection and correction function of frame head.

Generally, the TDM business datum will be implemented in to transmit among the GPON to be needed carry out packetization process, be packaged into the GEM frame by GEM client 221 earlier, be packaged into the GTC frame, finish the transmission on the GPM layer by GEM TC adaptation layer 212A, GTC framing sublayer 211 again, the TDM packet data encapsulation after the process packetization process is following three kinds of modes for the GEM frame mainly contains:

1), direct mapping mode:

G.984.3, ITU-T to be potted directly into the TDM grouped data in the GEM frame load how in informative annex I and only to have made simple conceptual description.Shown in Fig. 4 A, the TDM business grouping data is mapped directly in the Payload of GEM frame, and this mode expense is minimum, handles the simplest.Yet, for how circulating a notice of fault message etc. between the detection of TDM traffic failure, processing and OLT and the ONU, still do not make clear and definite standard, can not guarantee the interoperability of OLT and ONU.

2), PWE3 (edge-to-edge pseudo-line simulation) mode

PWE3 is a kind of technology based on IP or MPLS (multiprotocol label switching) packet switching network transmission artificial service that IETF (the Internet engineering duty group) proposes.

Shown in Fig. 4 B, in GPON, the TDM grouped data at first is packaged in the IP/UDP packet, is mapped in the GEM frame again.Yet because IP/UDP is three layer protocols, this mode encapsulates complexity, and the protocol processes expense is big, realizes complicated.

3), CESoETH (circuit emulation service of Ethernet bearing) mode

The MEF-8 suggestion of MEF (Metro Ethernet Forum) " the realization agreement of the PDH circuit emulation of Metro Ethernet carrying " standard provides an agreement of realization Metro Ethernet emulation PDH (Pseudo-synchronous Digital Hierarchy) (PDH) TDM business, especially, it contains the emulation of having covered N * 64kbit/s, DS1, E1, DS3 and E3 circuit, and this is commonly referred to the CESoETH mode.

Shown in Fig. 4 C, the TDM grouped data is packaged into earlier in the ethernet frame, is mapped in the GEM frame again.Although the more aforementioned PWE3 mode of its implementation is simple, reduced packet encapsulation and protocol processes expense, for the GPON network, it is unnecessary that its two layers of ethernet frame encapsulation still belongs to, and can bring a series of problems such as ether address configuration.

Summary of the invention

The invention provides a kind of simple and effective TDM business and in GPON, transmit implementation, support transmission control and management simultaneously the TDM business.

According to a first aspect of the invention, a kind of implementation method of Gigabit Passive Optical Network GPON carrier time division multiplexing TDM business comprises the steps: a), the TDM Circuit Service is carried out packetization process; B), generate a control field that is used for it in GPON transmission control for the TDM grouped data after the packetization process; C), execution kilomega passive optical network packaging method GEM frame encapsulates, and described TDM grouped data and control field is mapped to GEM Payload district.

According to a second aspect of the invention, a kind of kilomega passive optical network packaging method GEM frame structure that is used for carrier time division multiplexing TDM business, comprise GEM frame head and GEM frame Payload, wherein, described GEM frame Payload comprises TDM grouped data and a control field that is used for this TDM grouped data in GPON transmission control.

According to a third aspect of the present invention, the time division multiplexing tdm business processing device among a kind of Gigabit Passive Optical Network GPON comprises: mutual linkage function device, carry out packetization process to the TDM Circuit Service; Control device is for the TDM grouped data after the packetization process generates a control field that is used for it in GPON transmission control; The GEM packaging system is mapped to GEM frame Payload district with described TDM grouped data and control field, generates the GEM frame.

The present invention had both remedied the G.984.3 deficiency of mode, had avoided the unnecessary expense of PWE3 and CESoETH mode simultaneously.Existing system is changed few.

Description of drawings

Fig. 1 is a kind of typical communication system network structural representation;

Fig. 2 is a kind of typical GPON protocol stack structure;

Fig. 3 is a conventional structure of supporting the GEM frame of TDM and Ethernet service;

Fig. 4 A is that the TDM business is encapsulated into one of GEM frame mode-direct mapping mode;

Fig. 4 B is that the TDM business is encapsulated into one of GEM frame mode-PWE3 mode;

Fig. 4 C is that the TDM business is encapsulated into one of GEM frame mode-CESoETH mode;

Fig. 5 A is a TDM business processing flow among the GPON of the present invention;

Fig. 5 B is the control field frame mode that encapsulates in the GEM frame according to a specific embodiment of the present invention TDM business;

Fig. 5 C is encapsulated into GEM frame structure form according to a specific embodiment of the present invention TDM business;

Fig. 6 encapsulates in GPON according to a specific embodiment of the present invention TDM business to realize functional block diagram.

Embodiment

Below in conjunction with accompanying drawing, preferred implementation of the present invention is described in detail.

In conjunction with TDM business processing flow of the present invention shown in Fig. 5 A, it comprises step S51, S52, S53.

At first, in step S51, receive the TDM Circuit Service and it carried out packetization process formation TDM grouped data at the OLT or the ONU of GPON Way in,

Then, in step S52, OLT or ONU generate a control field that is used for this TDM grouped data in GPON transmission control.

Fig. 5 B further illustrates the control field structure embodiment that the TDM business encapsulates in the GEM frame, it comprises: a field L who is used to represent GPON Web portal direction TDM link failure, when being " 1 ", set represents that the OLT of GPON Web portal direction or ONU detect or be apprised of the TDM link failure, corresponding TDM grouped data may be invalid, and this TDM grouped data can be dropped to save bandwidth.A field R who is used for to the loss of frame failure of opposite end indication GPON network egress direction when the OLT of PON network egress direction or ONU carry out set to the R bit, represents that it does not receive the TDM grouped data from the PON network, enters the LOF state.A correction bit field M who is used for replenishing aforementioned field L implication is provided with by the OLT or the ONU of GPON Web portal direction, is used with the L field, but concrete implication agree as follows: 1), L=0, M=00, fault-free indication; 2), L=0, M=01,10: keep; 3), L=0, M=11: non-TDM grouped data (as, signaling); 4), L=1, the M=00:TDM link failure, the OLT or the ONU that will trigger opposite end GPON network egress direction produce AIS alarms such as (AISs); 5), L=1, M=01,10,11: keep.A FRG field that is used for TDM grouped data burst sign, concrete implication is as follows: 00: represent not burst; 01: indicate first burst; 10: indicate last burst; 11: burst in the middle of the sign.

At last, in step S53, OLT or ONU carry out the encapsulation of kilomega passive optical network packaging method (GEM) frame: it is mapped to GEM frame Payload district with described TDM grouped data and control field, and adds GEM frame head, formation GEM frame.

A kind of preferred implementation of the inventive method, among the above-mentioned steps S53, OLT or ONU are mapped to GEM frame Payload district head position with above-mentioned control field, with make things convenient for receiving terminal OLT or ONU to the location of control field and to control field entrained control information handle.For example: if position, L position in the control field, then receiving terminal can read the TDM grouped data that just directly abandons thereafter.Fig. 5 C illustrates that promptly TDM business of the present invention is encapsulated into GEM frame structure embodiment form, and GEM frame Payload 31 comprises TDM grouped data 311 and a control field 312 that is positioned at Payload district head position.

A kind of preferred implementation of the inventive method, when the GPON Way in has many TDM hardwired link, among the above-mentioned steps S52, can control field be provided with one be used to identify this TDM grouped data the field of corresponding TDM hardwired link CircuitID; Here what deserves to be explained is that even above-mentioned control field does not have the field of expression TDM hardwired link CircuitID, we can use the PortID in the GEM frame head that the TDM hardwired link is carried out mark.

Fig. 6 is that GEM client encapsulates realization functional structure embodiment block diagram to the TDM business among OLT of the present invention or the ONU in GPON, it comprises TDM business processing device 61, mutual

linkage function device

62a, 62b, 62c, control device 63, GEM encapsulation unit 64, wherein:

TDM business processing device 61, as a kind of option means, it carries out processing such as multiplexing and demultiplexing on the traditional circuit to the TDM Circuit Service that advances/go out the GPON network, and for example it can be many DS1/E1 hardwired link with a DS3/E3 hardwired link demultiplexing; Also many DS1/E1 hardwired link can be multiplexed with a DS3/E3 hardwired link.

Mutual linkage function device, illustrated in the legend that three mutual

linkage function device

62a, 62b, 62c are with respectively corresponding TDM hardwired link, in GPON Web portal direction, it converts the TDM Circuit Service of TDM business processing device 61 outputs to a series of TDM grouped datas.In GPON network egress direction, the most effective TDM grouped data of mutual linkage function device regenerates the TDM Circuit Service again, for invalid TDM grouped data, then according to relevant criterion corresponding TDM circuit time slot is filled.

Control device 63, in GPON Web portal direction, the control field that this TDM grouped data of an expression of its generation is transmitted in GPON also is provided with, the functional definition of control field, the existing description in version front, for example: when GPON Web portal direction detect or be apprised of TDM hardwired link fault the time, L field set in 63 pairs of control fields of control device is " 1 ", and corresponding TDM grouped data may be invalid, and this TDM grouped data can be dropped to save bandwidth; When GPON network egress direction is not received the TDM grouped data and when entering the LOF state, the R field set in 63 pairs of control fields of control device is " 1 ", so that this incident is indicated to the opposite end from the PON network.According to legend suggestion execution mode, it also needs further to identify the corresponding TDM hardwired link CircuitID of this TDM grouped data, and corresponding C ircuitID promptly is set in control field; In GPON network egress direction, it extracts the corresponding control field of TDM grouped data and carries out respective handling according to its control information of carrying, for example: control information field L=1, M=00: it will produce the ais alarm indication; The TDM grouped data is sent to the mutual linkage function device of its correspondence etc. according to the CircuitID field.

GEM packaging system 64 receives TDM grouped data and corresponding control field from control device 63, and it is mapped to GEM frame Payload, adds the GEM frame head, forms the GEM frame; And the GEM frame that receives from the TC layer carried out decapsulation, output TDM grouped data and corresponding control field.

A kind of preferred structure execution mode of apparatus of the present invention, GEM packaging system 64 is mapped to GEM frame Payload district head position with control field, handles to the location of control field and to entrained control information to make things convenient for receiving terminal OLT or ONU.For example: the OLT control device 63 of GPON Way out is position, L position in control field, then can read just directly to abandon the TDM grouped data.

What deserves to be explained is, the field that does not have sign TDM hardwired link CircuitID when above-mentioned control field, control device 63 can be exported to GEM packaging system 64 with TDM grouped data and corresponding TDM hardwired link, and the GEM packaging system is identified the TDM hardwired link by the PortID in the GEM frame; Simultaneously, to the GEM frame from the TC layer, it also can extract the PortID in the GEM frame head, and the TDM grouped data after the decapsulation is transmitted to control device 63 together, and control device 63 promptly can be distributed to the TDM grouped data corresponding mutual linkage function device.

Although above-mentioned being illustrated as the invention provides some embodiment; be not to be used for limiting protection scope of the present invention; the professional in present technique field can carry out various modifications to embodiment under the prerequisite that does not depart from the scope of the present invention with spirit, this modification all belongs in the scope of the present invention.

Claims

1. the implementation method of a Gigabit Passive Optical Network GPON carrier time division multiplexing TDM business comprises the steps:

A), the TDM Circuit Service is carried out packetization process;

B), for the TDM grouped data after the packetization process generates a control field that is used for it in GPON transmission control, comprise a field and a field that is used for to the loss of frame failure of opposite end indication GPON network egress direction that is used to represent GPON Web portal direction TDM link failure in the wherein said control field;

C), execution kilomega passive optical network packaging method GEM frame encapsulates, and described TDM grouped data and control field is mapped to GEM frame Payload district.

2. the method for claim 1 is characterized in that in the described step c), and described control field is mapped to GEM frame Payload district head position.

3. method as claimed in claim 1 or 2 is characterized in that in the described step b), also has a field that is used to represent the corresponding TDM hardwired link of described TDM grouped data CircuitID in the described control field.

4. method as claimed in claim 1 or 2 is characterized in that in the described step c), and the GEM frame uses frame head middle port mark PortID to represent described TDM grouped data corresponding circuits link.

5. the time division multiplexing tdm business processing device in the Gigabit Passive Optical Network GPON network comprises:

Mutual linkage function device: the TDM Circuit Service is carried out packetization process;

Control device:, comprise a field and a field that is used for to the loss of frame failure of opposite end indication GPON network egress direction that is used to represent GPON Web portal direction TDM link failure in the wherein said control field for the TDM grouped data after the packetization process generates a control field that is used for it in GPON transmission control;

GEM packaging system: described TDM grouped data and control field are mapped to GEM frame Payload district, generate the GEM frame.

6. device as claimed in claim 5 is characterized in that described GEM packaging system is mapped to GEM frame Payload district head position with control field.

7. as claim 5 or 6 described devices, it is characterized in that described control device is provided with a TDM hardwired link CircuitID field and is used to identify the corresponding mutual linkage function device of described TDM grouped data in described control field.

8. as claim 5 or 6 described devices, it is characterized in that described GEM packaging system uses GEM frame head middle port mark PortID to identify the corresponding mutual linkage function device of described TDM grouped data.