CN102625197B - Method and system for transmitting EPON (Ethernet Passive Optical Network) frame on coaxial cable, and coaxial end - Google Patents
Method and system for transmitting EPON (Ethernet Passive Optical Network) frame on coaxial cable, and coaxial end Download PDFInfo
- Publication number
- CN102625197B CN102625197B CN201210057499.0A CN201210057499A CN102625197B CN 102625197 B CN102625197 B CN 102625197B CN 201210057499 A CN201210057499 A CN 201210057499A CN 102625197 B CN102625197 B CN 102625197B
- Authority
- CN
- China
- Prior art keywords
- frame
- coaxial
- epon
- timer
- epon frame
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Small-Scale Networks (AREA)
Abstract
The invention provides a coaxial transmission system for transmitting an EPON (Ethernet Passive Optical Network) frame. The system is characterized by comprising a coaxial first end and a coaxial second end, wherein the coaxial first end is used for packaging the EPON frame onto a physical frame; the coaxial second end is used for de-packaging the physical frame into the EPON frame; and a delay control mechanism is adopted between the coaxial first end and the coaxial second end. The system provided by the embodiment of the invention is used for realizing the transmission of the EPON frame on a coaxial cable network; the end-to-end Qos is ensured; and the difficulty and cost for realizing the technology are reduced.
Description
Technical field
The present invention relates to EPON frame tranmission techniques, particularly a kind of method and system, same axle head transmitting EPON frame on coax.
Background technology
The rise and development of various Internet service proposes more and more higher bandwidth requirement to network, under the background of backbone network fiberize, the Access Network being called as " last 100 meters " becomes the bottleneck restricting whole wideband day by day, the access technologies such as traditional ADSL (Asymmetric Digital Subscriber Line, ADSL (Asymmetric Digital Subscriber Line)) cannot meet growing bandwidth requirement.FTTH (Fiber To The Home, fiber entering household) be considered to the ultimate technology realizing broadband access, but there is the problems such as price height and constructional difficulties, can not popularize fast, the broadband access utilizing the coaxial cable of existing a large amount of laying to realize last 100 meters is the selection of a high performance-price ratio, but there are some problems.
EPON (Ethernet Passive Optical Network, EPON based on Ethernet mode)+EOC (Ethernet over Coaxial, transmit Ethernet on coaxial) scheme in, the upper transmission of EPON be ethernet data frame, hereinafter referred to as EPON frame.EOC realizes point-to-multipoint two-way communication on coaxial, EOC transmitting terminal is modulated into base band or the radiofrequency signal of applicable coaxial transmission after being packed by ethernet data frame, EOC receiving terminal carries out solution mediation to the base band received or radiofrequency signal and unpacks, and is reduced into ethernet data frame.In order to realize point-to-multipoint communication mechanism, define a set of MAC protocol adapted to it to the management of coaxial bandwidth resources and QoS, EOC.From network hierarchy model, EOC is a two-layer equipment and technology.
The major defect of EPON+EOC does not have unified QoS (Quality of Service, service quality) to ensure.EPON can realize more perfect QoS and ensure; The QoS of EOC technology itself is also more and more perfect, but both QoS are separate and isolation, and they are together as a complete Access Network, and total QoS performance existing defects, is unfavorable for carrying out of Operator Specific Service end to end.
Be entitled as in " Ethernet Passive Optical Network over Coaxial " US Patent No. 20110058813, network configuration and EPON+EOC similar, but on coaxial, only do physical layer conversion, by the MAC protocol of EPON from extension of optical fiber to coaxial, and through CNU (Customer Network Unit, user network unit).Local side apparatus directly can manage and to the bandwidth resources on CNU, avoid two-part QoS from OLT (Optical Line Terminal, optical fiber cable termination equipment), is the solution of end-to-end QoS.
But, owing to only doing physical layer conversion at CMC (Coaxial Media Convertion, coaxial medium transition period), no matter CNU actual institute dedicated bandwidth is how many, all need all data streams from OLT to be put into coaxial upper transmission, need the coaxial frequency spectrum taking non-constant width.That is, CMC equipment and CNU equipment need the signal processing the non-constant width of frequency spectrum, and technology realizes difficulty, cost and power consumption all can be very high.When EPON is upgraded to 10G from 1G in the future, these costs all can increase greatly.
Summary of the invention
For solving the problem, the invention provides a kind of the coaxial transmission system and method, the hybrid communication system that transmit EPON frame, and same axle head.
First aspect, the invention provides a kind of coaxial transmission system transmitting EPON frame of described system, described system comprises coaxial first end and coaxial second end; Wherein, EPON frame is encapsulated into physical frame by coaxial first end, and physical frame is descapsulated into EPON frame by coaxial second end; Delays time to control mechanism is adopted between coaxial first end and coaxial second end.
On the other hand, the invention provides a kind of hybrid communication system, comprise optical fiber cable termination equipment and user network unit, and be connected to the foregoing coaxial transmission system between optical fiber cable termination equipment and user network unit.
Another aspect, the invention provides a kind of coaxial transmission method transmitting EPON frame, described method comprises:
EPON frame is encapsulated into physical frame;
By coaxial transmission system transfers physical frame;
Physical frame decapsulation is obtained EPON frame;
Wherein, delays time to control mechanism is adopted in the transmitting procedure of EPON frame.
Again on the one hand, the invention provides a kind of same axle head transmitting EPON frame, EPON frame is encapsulated into physical frame by described same axle head, physical frame is descapsulated into EPON frame by coaxial opposite end; Delays time to control mechanism is adopted with between axle head and coaxial opposite end.
Finally, the invention provides a kind of same axle head transmitting EPON frame, described coaxial termination receives the physical frame being packaged with EPON frame from coaxial opposite end, physical frame is descapsulated into EPON frame; Delays time to control mechanism is adopted with between axle head and coaxial opposite end.
Present invention achieves the transmission of EPON frame on coax network, both provided end-to-end Qos to ensure, and again reduced and realize difficulty.
Accompanying drawing explanation
Fig. 1 is that the coaxial circuit that utilizes of the embodiment of the present invention transmits the access network architecture schematic diagram of EPON frame;
Fig. 2 is the method schematic diagram of the coaxial circuit transmission EPON frame of the embodiment of the present invention;
Fig. 3 is the schematic diagram of frame extended method in the coaxial circuit of the embodiment of the present invention;
Fig. 4 is the schematic diagram of frame method of reducing in the coaxial circuit of the embodiment of the present invention;
Fig. 5 is the schematic diagram of EPON frame Buffer output method in the coaxial circuit of the embodiment of the present invention.
Embodiment
Fig. 1 is that the coaxial circuit that utilizes of the embodiment of the present invention transmits the access network architecture schematic diagram of EPON frame.As shown in Figure 1, EPON frame can carry out two-way transmission on coaxial circuit, thus can by the sphere of action of EPON protocol stack is from extension of optical fiber to coaxial circuit, and stops CNU (Customer Network Unit, user network unit) is upper.OLT (optical line terminal, optical fiber cable termination equipment) directly use the MAC layer Frame of EPON to communicate with protocol stack with CNU, coaxial cable is completely transparent for their part, thus can achieve substituting of fiber entering household by the mode of this low cost of coaxially registering one's residence.
In Fig. 1, (I) is FTTH (Fiber To The Home, fiber entering household) application, (II) be the point-to-point application of the embodiment of the present invention, (III) for the point-to-multipoint of the embodiment of the present invention is applied, these three kinds of modes can in same Optical Access Network mixed networking.The core means of the embodiment of the present invention are at ONU (Optical Network Unit, optical network unit) in optical transceiver and CNU between insert coaxial cable communications systems, wherein, coaxial telecommunications equipment near OLT side is referred to as coaxial headends, coaxial telecommunications equipment near CNU side is referred to as coaxial termination, GMII (the Gigabit Medium Independent Interface of standard is adopted between coaxial headends and optical transceiver, gigabit Media Independent Interface) interface, also adopt gmii interface between coaxial termination and CNU.Above-mentioned GMI PCI interface also can adopt other interface to replace, and does not limit at this.
Fig. 2 is the method schematic diagram of the coaxial circuit transmission EPON frame of the embodiment of the present invention.In Fig. 2 point-to-point/point-to-multipoint coaxial telecommunications 201 can adopt various existing communication technology to realize, such as FEC (Forward Error Correction, forward error correction) coding&decoding function, single carrier or multi-carrier modulation demodulation function, FDD (Frequency Division Duplexing, Frequency Division Duplexing (FDD)) duplex mode, TDD (Time Division Duplexing, time division duplex) duplex mode, point-to-multipoint TDMA (Time Division Multiple Access, time division multiple access) multi-access mode, point-to-multipoint OFDMA (Orthogonal Frequency Division Multiple Access, OFDM) etc.In addition communication process also comprise the envelope of physics in corresponding diagram 2 frame from EPON frame to physics the encapsulation of communication physical frame and corresponding diagram 2 tear open frame from communication physical frame to the decapsulation process of EPON frame.
For the coaxial communication of above-mentioned insertion, unless lowered efficiency with flexibility, otherwise communication system to guarantee that between transmitting-receiving, time delay is constant well, be non-constant specific to the transmission delay being exactly reference point R1.1 to R2.1 in Fig. 2, the transmission delay of reference point R2.2 to R1.2 is also non-constant.The non-constant meeting of this transmission delay causes the inefficacy of whole EPON frame traffic in Fig. 2.
For solving above-mentioned time delay persistent problem, the present invention in fig. 2 point-to-point/point-to-multipoint coaxial telecommunications 201 outside use extra delays time to control mechanism to guarantee that between transmitting-receiving, time delay is constant, constant such as from reference point K1.1 to K2.1 transmission delay, realize constant from reference point K1.2 to K2.2 transmission delay, this time delay is constant can guarantee that the distance measurement function of the MAC layer Frame of EPON is effective, thus reaches the beneficial effect that realization transmits EPON frame on coax.
Above-mentioned delays time to control mechanism specific implementation as shown in Figure 2, all each self-contained timer in coaxial headends and coaxial termination.Timer 202 free-running operation in coaxial headends, the timer 203 in coaxial termination needs regularly or carries out synchronous with the timer in coaxial headends aperiodically, in the also free-running operation of this timer of asynchronous moment.That is, be need regular or irregular master-slave synchronisation relation between timer 202 and timer 203.Above-mentioned synchronous object makes the difference of the clocking value between coaxial headends and the timer of coaxial termination keep constant.A kind of concrete mode is synchronously such: the timer value of the timer 202 of coaxial headends is sent to the timer 203 of coaxial termination by communication system, and coaxial termination uses the clocking value received to replace the timer value of current timer 203.The communication channel that transmission delay shown in the transmission of above-mentioned timer value to use in Fig. 2 between reference point R1.3 to R2.3 is fixing.Fix to realize transmission delay, timer synchronization communication channel used is reliable but poor efficiency, and because the frequency of timer synchronization is very low, data volume is also very little, and the expense therefore shared by this channel is very little, very little on the impact of entire system efficiency.
As Fig. 2, the embodiment of the present invention carries out frame extension process to the EPON frame entering coaxial headends from gmii interface from optical fiber cable termination equipment OLT, then carry out LLID (Logical Link Identifier, LLID) to the EPON frame after expansion to filter.Above-mentioned filter condition is for whether the EPON frame after described expansion is for whether broadcast frame or its LLID field mate with the LLID of the CNU be connected after coaxial headends.The EPON frame meeting above-mentioned filter condition is only had just to allow to carry out coaxial transmission, namely only have broadcast frame just to allow to carry out coaxial transmission with the expansion EPON frame that the LLID of the CNU be connected after this coaxial headends mates with LLID field, but not broadcast frame or LLID unmatched expansion EPON frame can be dropped.Expansion EPON frame through coaxial transmission flows into user network unit CNU from the gmii interface of coaxial termination at coaxial termination after frame reduction treatment and Buffer output process.
Above by the scheme that LLID filters, obviously can reduce the speed of the EPON frame from OLT, thus meet the required communication rate on coaxial cable, technology of being convenient to realizes, and reduces and take expense to coaxial frequency spectrum resource.
As Fig. 2, the embodiment of the present invention carries out frame extension process to the EPON frame entering coaxial termination from gmii interface from user network unit CNU, then the EPON frame after expansion is carried out coaxial transmission, the expansion EPON frame through coaxial transmission flows into optical fiber cable termination equipment OLU from the gmii interface of coaxial headends in coaxial headends after frame reduction treatment and Buffer output process.Be noted that above-mentioned buffered is a preferred means before output, other means can be adopted to replace, do not limit at this.
Fig. 3 is the schematic diagram of frame extended method in the coaxial circuit of the embodiment of the present invention.Preamble structure as Fig. 3, EPON Ethernet net frame comprises 8 bytes, is followed successively by 0x55,0x55, SPD, 0x55,0x55, LLID [15:8], LLID [7:0], CRC8.Wherein SPD is used to indicate the position of LLID and cyclic redundancy check (CRC) position CRC8, and CRC8 is the most-significant byte that the CRC of data between 3 to 7 bytes, LLID [15:8] represent LLID, and LLID [7:0] represents the least-significant byte of LLID.
During expansion, before the lead code of EPON Ethernet net frame, add length field and ATS (Arrival Time Stamp, the time of advent stabs) field.Wherein length field takies 2 bytes; ATS field takies 4 bytes, fills with the currency of the timer of axle head with frame expansion place.Then, FCS (Frame Check Sequence, frame detects sequence) is calculated to the EPON frame data after the expansion comprising newly-increased length field and ATS field, result of calculation is filled into FCS field, obtains the EPON frame after final expansion.A kind of method of described calculating FCS is the method specified in IEEE802.3 agreement.
Fig. 4 is the schematic diagram of frame method of reducing in the coaxial circuit of the embodiment of the present invention.In the diagram, receiving terminal carries out FCS verification to the expansion EPON frame obtained after tearing frame process open through physics, and the not right frame of verification directly abandons, and verifies correct frame and carries out frame reduction treatment.Described receiving terminal is coaxial headends or coaxial termination.The process of frame reduction is stripped down from expansion EPON frame newly-increased length field during expansion and ATS field, and according to the code requirement of Ethernet, recalculate FCS value and be filled into FCS field, obtaining the EPON frame after reduction.
Fig. 5 is the schematic diagram of EPON frame Buffer output method in the coaxial circuit of the embodiment of the present invention.
EPON frame described here refers to the EPON frame after above-mentioned reduction.As shown in Figure 5, the ATS stripped down during frame reduction and length value enter FIFO (First Input First Output, first in first out) buffer queue, during buffering, keep the corresponding relation of EPON frame and length, ATS, such as: length 4, ATS4 is all corresponding reduce after EPON frame 4.By length and ATS control EPON frame to the sending action of the transmit button of GMI PCI interface with send and continue duration, wherein ATS determines start time of sending, and length determines the duration sent.
The start time of above-mentioned transmission is determined like this:
(1) ATS value adds that constant time lag value is as transmitting time designated value
(2) when the transmitting time designated value that first the EPON frame cushioned in FIFO is corresponding equals timer value, then start to send this EPON value.
Specific requirement for above-mentioned constant time lag value is: in coaxial termination, and this constant time lag value is more than or equal to the maximum delay that in Fig. 2, reference point R1.1 to R2.1 is possible; In coaxial headends, this constant time lag value is more than or equal to the constant transmissions time delay that maximum delay that in Fig. 2, reference point R2.2 to R1.2 is possible adds reference point R1.3 to R2.3.In order to ensure the high reliability of system, can constant time lag value be arranged slightly larger under the prerequisite meeting above-mentioned requirements.
In sum, the embodiment in the present invention is only preferred embodiment of the present invention, not for being limited to protection scope of the present invention.Within the spirit and principles in the present invention all, any amendment made, equivalent replacement, improvement etc., all because being included within protection scope of the present invention.
Claims (11)
1. transmit a coaxial transmission system for EPON frame, it is characterized in that, described system comprises coaxial first end and coaxial second end; Wherein, EPON frame is encapsulated into physical frame by coaxial first end, and physical frame is descapsulated into EPON frame by coaxial second end; Delays time to control mechanism is adopted between coaxial first end and coaxial second end; At least one in described coaxial first end and the second end comprises LLID filtering module, for filtering EPON frame.
2. the system as claimed in claim 1, is characterized in that, at least one in described coaxial first end and the second end comprises frame expansion module, for expanding EPON frame.
3. the system as claimed in claim 1, is characterized in that, at least one in described coaxial first end and the second end comprises frame recovery module, for the EPON frame of expansion is reduced into the EPON frame before expansion.
4. the system as claimed in claim 1, it is characterized in that, described coaxial first end comprises the first timer, coaxial second end comprises the second timer, its timer value is passed to the second timer by the first timer, so that the second timer replaces the current counter value of the second timer according to this timer value, realize delays time to control mechanism thus.
5. the system as claimed in claim 1, is characterized in that, described coaxial first end corresponds to multiple coaxial second end.
6. the system as claimed in claim 1, is characterized in that, coaxial first end and the second end adopt gigabit Media Independent Interface.
7. a hybrid communication system, comprises optical fiber cable termination equipment and user network unit, and is connected to the system as described in claim 1-6 between optical fiber cable termination equipment and user network unit.
8. transmit a coaxial transmission method for EPON frame, it is characterized in that, described method comprises:
EPON frame is encapsulated into physical frame;
By coaxial transmission system transfers physical frame;
Physical frame decapsulation is obtained EPON frame;
Wherein, delays time to control mechanism is adopted in the transmitting procedure of EPON frame;
Described step EPON frame being encapsulated into physical frame comprises carries out LLID filtration to EPON frame.
9. method as claimed in claim 8, is characterized in that, described method comprises and realizes delays time to control mechanism by transmitting timer value.
10. method as claimed in claim 8, it is characterized in that, described step EPON frame being encapsulated into physical frame comprises to be expanded EPON frame.
11. methods as claimed in claim 10, is characterized in that, described step physical frame decapsulation being obtained EPON frame comprises the EPON frame of expansion is reduced into the EPON frame before expansion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210057499.0A CN102625197B (en) | 2012-03-06 | 2012-03-06 | Method and system for transmitting EPON (Ethernet Passive Optical Network) frame on coaxial cable, and coaxial end |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210057499.0A CN102625197B (en) | 2012-03-06 | 2012-03-06 | Method and system for transmitting EPON (Ethernet Passive Optical Network) frame on coaxial cable, and coaxial end |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102625197A CN102625197A (en) | 2012-08-01 |
| CN102625197B true CN102625197B (en) | 2015-06-10 |
Family
ID=46564849
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210057499.0A Active CN102625197B (en) | 2012-03-06 | 2012-03-06 | Method and system for transmitting EPON (Ethernet Passive Optical Network) frame on coaxial cable, and coaxial end |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102625197B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106992919A (en) * | 2017-03-31 | 2017-07-28 | 信阳师范学院 | FTTdp+GDSL group network systems |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101808344A (en) * | 2009-08-17 | 2010-08-18 | 华中科技大学 | Ethernet passive electric network |
| WO2011031831A1 (en) * | 2009-09-09 | 2011-03-17 | Broadcom Corporation | Ethernet passive optical network over coaxial (epoc) |
| CN102098195A (en) * | 2010-12-14 | 2011-06-15 | 田鹰 | Coaxial-cable Ethernet over coax (EOC) system with upgrade function and control method thereof |
-
2012
- 2012-03-06 CN CN201210057499.0A patent/CN102625197B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101808344A (en) * | 2009-08-17 | 2010-08-18 | 华中科技大学 | Ethernet passive electric network |
| WO2011031831A1 (en) * | 2009-09-09 | 2011-03-17 | Broadcom Corporation | Ethernet passive optical network over coaxial (epoc) |
| CN102098195A (en) * | 2010-12-14 | 2011-06-15 | 田鹰 | Coaxial-cable Ethernet over coax (EOC) system with upgrade function and control method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102625197A (en) | 2012-08-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20210143913A1 (en) | Communication system and method for an optical local area network | |
| US10462028B2 (en) | Efficient ethernet signal transport and scheduling | |
| JP4169595B2 (en) | Point-to-multipoint passive optical network using variable-length packets | |
| US7925162B2 (en) | Communication system and method for an optical local area network | |
| EP2719192B1 (en) | A method of providing end-to-end connection in a unified optical and coaxial network | |
| CN102740173B (en) | Method for sub-rating Ethernet passive optical network (epon) medium access control (mac) flow and physical layer chip | |
| US8126335B2 (en) | Methods and apparatus for next generation access passive optical networks | |
| US9537573B2 (en) | Systems and methods for extending optical network services across non-optical channels | |
| US8462656B2 (en) | Method and apparatus for multi-service adaptation and carriage | |
| US20030137975A1 (en) | Ethernet passive optical network with framing structure for native Ethernet traffic and time division multiplexed traffic having original timing | |
| CN111095860B (en) | Method and device for clock synchronization | |
| WO2010020130A1 (en) | A packet add/drop multiplexing device and a data transmission method of a packet add/drop multiplexing device | |
| CN101753578B (en) | ETHERNET/EI protocol conversion method and protocol converter | |
| WO2010096993A1 (en) | A service adaptation method and service adaptation device | |
| WO2020074007A1 (en) | Link establishment method and apparatus, and computer readable storage medium | |
| WO2010048837A1 (en) | Service transmission method and device used for service transmission | |
| CN104618019A (en) | WiFi (wireless fidelity) access system based on visible light transmission and data frame transformation method | |
| EP2601750A1 (en) | Hybrid orthogonal frequency division multiplexing time domain multiplexing passive optical network | |
| US20130343753A1 (en) | Methods and systems for implementing time-division duplexing in the physical layer | |
| US20220116269A1 (en) | Apparatus and methods for synchronization pattern configuration in an optical network | |
| CN105187161B (en) | The transmission method and device of a kind of CPRI frame over ethernet | |
| WO2010091556A1 (en) | Method for burst transmission on a passive optical network, method and device for receiver resetting | |
| EP2865116B1 (en) | Fiber-coax unit | |
| CN102625197B (en) | Method and system for transmitting EPON (Ethernet Passive Optical Network) frame on coaxial cable, and coaxial end | |
| CN201536409U (en) | Passive optical network broad band access system based on Ethernet |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |