KR101050658B1 - How to Set the Transmission Cycle to Accept Fast Ethernet on the Residential Ethernet - Google Patents

Abstract

1. Technical field to which the invention described in the claims belongs

Field of the Invention [0002] The present invention relates to a Residential Ethernet capable of efficiently providing a real-time service and a non-real-time service simultaneously using Ethernet, and more particularly to a method of guaranteeing transmission of asynchronous data when synchronous data is transmitted using high- .

2. Technical Challenges to be Solved by the Invention

The present invention provides a method of setting a transmission cycle for accommodating Fast Ethernet in a Residential Ethernet in which a Fast Ethernet having a transmission speed of 100 Mbps is accommodated in a Residential Ethernet system and at least one area is allocated to an asynchronous packet in one transmission interval It has its purpose.

3. The point of the solution of the invention

The present invention provides a method for setting a transmission cycle for data transmission in a Residential Ethernet device capable of efficiently providing a real-time service and a non-real-time service simultaneously using Ethernet, the method comprising: A first step of receiving an asynchronous packet for a non-real-time service and generating a super frame according to a reference transmission cycle; A second step of checking whether at least one asynchronous packet is included in the super frame generated in the first step; A third step of generating a second super frame in which the super frame is extended to a predetermined multiple if the at least one asynchronous packet is not included in the super frame; And a fourth step of transmitting the data through the second super frame by inserting the predetermined multiple information into the header of the generated second super frame.

4. Important Uses of the Invention

The present invention is applied to Residential Ethernet and the like.

Residential Ethernet, super frame, transmission cycle

Description

(Transmission Cycle Setup Method for Adopting Fast Ethernet in Residential Ethernet)

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a transmission structure diagram of an embodiment in Residential Ethernet strictly keeping the start of a conventional superframe. Fig.

2 is an exemplary diagram illustrating a conventional problem with occupancy of one transmission cycle that can occur when using Fast Ethernet;

FIG. 3 is a diagram illustrating an example of a case where a transmission cycle is set twice according to a transmission cycle setting method according to the present invention. FIG.

4 is a detailed structural diagram of one transmission cycle in a Residential Ethernet system according to the present invention;

5 is a flowchart illustrating a method of setting a transmission cycle for accommodating Fast Ethernet in Residential Ethernet according to an embodiment of the present invention.

Field of the Invention [0002] The present invention relates to a Residential Ethernet capable of efficiently providing a real-time service and a non-real-time service simultaneously using Ethernet, and more particularly to a method of guaranteeing transmission of asynchronous data when synchronous data is transmitted using high- will be.

Ethernet is the most widely deployed LAN technology. Ethernet is originally developed by Xerox and developed by Xerox, DEC and Intel, although it is now defined as a standard in IEEE Institute of Electrical and Electronics Engineers (IEEE) 802.3.

Since the conventional Ethernet is competitively accessed using the CSMA / CD (Carrier Sense Multiple Access / Collision Detect) protocol defined in IEEE 802.3, the service frame of the upper layer is maintained as an Ethernet frame And transmits it. At this time, transmission is performed in the order of occurrence regardless of the type of the upper service frame. In other words, Ethernet is one of the most commonly used techniques to transfer data between different terminals or between users.

Although Ethernet is known as a technology which is not suitable for video or voice transmission sensitive to transmission time delay, in recent years, technologies for transmitting synchronous data such as video / audio using existing Ethernet have been actively discussed The Ethernet for the transmission of the synchronization data discussed above is called Residential Ethernet.

In Residential Ethernet, frame transmission is done on a cycle-by-frame basis. In general, 125 μs is defined as one cycle. One cycle is divided into a section capable of transmitting a synchronous frame and a section transmitting an asynchronous frame. A frame following this one cycle is called a super frame.

However, when implementing the Residential Ethernet as described above, when the start of the superframe is strictly applied (that is, when transmission of the synchronous frame is started at the start of the superframe), a method of forcibly holding or dividing the asynchronous frame The bandwidth utilization for the asynchronous frame is greatly reduced.

FIG. 1 is a transmission structure diagram of an embodiment in a Residential Ethernet strictly keeping the start of a conventional superframe.

Referring to FIG. 1, in a Residential Ethernet which strictly keeps the start of a conventional superframe, a transmission cycle for data transmission is configured as a superframe of 125 microseconds, and each superframe includes synchronization areas 11-1 and 11-2 And non-synchronization areas 12-1 and 12-2.

As shown in FIG. 1, in the Residential Ethernet which strictly keeps the start of the conventional superframe, the start (101, 102, 103) of the superframe is synchronized with the start The transmission of the frames 111-1 to 111-11 is performed.

To do this, the last Async frames 112-2 and 112-4 of each superframe should be processed according to the end of the superframe. Such a processing method includes a hold method, a fragmentation method, and a method of making a hold method and a division method.

Here, if the size of the Async frame to be transmitted exceeds the size of the remaining area of the current superframe, the hold method holds the Async frame to strictly keep the start of the next superframe and transmits it to the next superframe, The remaining area is the empty transmission method.

If the size of the Async frame to be transmitted exceeds the size of the remaining area of the current superframe, the Async frame is divided to fit the size of the remaining area of the current superframe in order to strictly keep the start of the next superframe, And transmits the remaining second Async frame divided into the next super frame.

If the remaining area of the current superframe is equal to or larger than the threshold value, a dividing method is used. If the remaining area of the current superframe is less than the threshold value, It is a method to use the method.

Considering Residential Ethernet as above, synchronous packet transmission is guaranteed within a prescribed cycle of 125 μs, and asynchronous packets must be transmitted in the remaining interval as much as the available length. However, in Residential Ethernet, synchronous packets can be from a minimum of 64 bytes to a maximum of 1518 bytes. If Fast Ethernet is applied, the total amount of data that can be transmitted during 125 microseconds is 1562 bytes. Therefore, even if the length of the sync packet is fixed at 1518 bytes in the worst case, even if the gap between the packets is not given, the size of the remaining area excluding the sync packet in the transmission cycle is smaller than the minimum Ethernet packet length of 64 bytes can not do it. In addition, due to the nature of the synchronous packet, packets of similar capacity continue to be successively transmitted, so that only the synchronous packet can continue to be transmitted thereafter, and other data can not be transmitted. This will be described in more detail with reference to FIG.

2 is an exemplary diagram illustrating a conventional problem with regard to occupation of one transmission cycle that may occur when using Fast Ethernet;

As shown in FIG. 2, one 125 [micro] sec transmission cycle can transmit 1562 bytes [24], and when using Fast Ethernet, the size of the synchronization packet 21 can be up to 1518 bytes.

Thus, if this happens, the remaining extra area of the 125 μs transfer cycle is only 44 bytes. However, the size of the asynchronous packet 22 to be transmitted needs to be at least 64 bytes. Thus, the asynchronous packet 22 is not transmitted in the corresponding transmission cycle 24. [

Then, it is necessary to perform transmission by waiting for the next cycle. Due to the characteristics of the synchronous packet, transmission of the asynchronous packet 22 can not be performed for a while because a packet of a similar size is continuously transmitted.

In addition, since it is impossible to transmit only one synchronous packet in one cycle, it is difficult to maintain a 125 μs transmission cycle because it is difficult to secure an area for transmission of an asynchronous packet as well as another synchronous packet.

In order to solve this problem, attempts have been made to solve such a problem by using a method of maintaining a 125 [micro] s transmission cycle every predetermined period without strictly observing the transmission cycle. However, when such a method is used, each transmission cycle is irregular And the load in the process of processing the packet increases.

The present invention has been proposed in order to solve the above-mentioned problems, and it is an object of the present invention to provide a residential Ethernet system that accommodates fast Ethernet having a transmission rate of 100 Mbps and allocates at least one area for asynchronous packets in one transmission interval It is an object of the present invention to provide a method of setting a transmission cycle to accommodate Fast Ethernet in Ethernet.

According to an aspect of the present invention, there is provided a method for setting a transmission cycle for data transmission in a Residential Ethernet device capable of efficiently providing a real-time service and a non-real-time service simultaneously using Ethernet, A first step of receiving a synchronous packet for the non-real-time service and a super frame according to the reference transmission cycle by receiving the asynchronous packet for the non-real-time service; A second step of checking whether at least one asynchronous packet is included in the super frame generated in the first step; A third step of generating a second super frame in which the super frame is extended by a predetermined multiple if at least one asynchronous packet is not included in the super frame as a result of the second step; And a fourth step of transmitting the data through the second super frame by inserting the predetermined multiple information into the header of the generated second super frame.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In the embodiment of the present invention, in order to allocate at least one area for an asynchronous packet in one transmission period while accommodating Fast Ethernet having a transmission speed of 100 Mbps in a Residential Ethernet system, at least one synchronization packet And at least one asynchronous packet.

In this case, in the case of strictly maintaining the 125 μs transmission cycle, as described above, when the fast Ethernet is supported, it is impossible to deliver even one asynchronous packet in the worst case.

Accordingly, the present invention proposes a transmission cycle setting method for accommodating Fast Ethernet in a Residential Ethernet that allows transmission of a synchronous packet supporting high-speed Ethernet and at least one asynchronous packet by extending a transmission interval by a predetermined multiple in Residential Ethernet I want to.

FIG. 3 is a diagram illustrating an example of a case where a transmission cycle is set twice according to a transmission cycle setting method according to an embodiment of the present invention.

3, if the size of the superframe is 2 * 125 .mu.s, even if the size of the sync packet supporting Fast Ethernet is 1518 bytes, two sync packets 31 and 32 and an extra area 33 of 88 bytes ).

As described above, the present invention extends the length of a transmission cycle to accommodate fast Ethernet in Residential Ethernet, thereby enabling smooth data transmission. At this time, the length of the cycle may be increased randomly by a certain multiple. However, in Residential Ethernet, since the synchronous packet that requires real-time processing is transmitted, increasing the length of the transmission cycle by itself does not satisfy the QoS. Therefore, it is possible to set the size of the transmission cycle to be increased so long as the QoS is satisfied. In general, QoS is assumed to be sustainable in a transmission cycle of 4 * 125 μs.

According to the present invention, the size of the transmission cycle is controlled to be set to a predetermined multiple, thereby ensuring the transmission area of the asynchronous packet. At this time, the size of the transmission cycle can be set to be ⁿ times, 2n times, or 2 ⁿ times. As mentioned above, in general, if the value of n is too large, it is difficult to continuously process the synchronization packet at the receiving end. Therefore, the value of n should be 2 or less.

When the size of the transmission cycle is extended by a predetermined multiple, it must be possible to confirm whether the transmission cycle is an extended transmission cycle. To this end, the configuration information of the transmission cycle is displayed in a predetermined space among the packets transmitted through the transmission cycle, so that information on the transmission cycle can be informed to the next node.

That is, when the length of the transmission cycle is increased, information on the length of the extended transmission cycle must be shared by the receiving communication terminal or the device so that the information can be transmitted smoothly without missing the synchronous packet and the asynchronous packet.

Therefore, it is necessary to transmit information on the length of the transmission cycle. One way is to add a new header to the header of the Residential Ethernet packet, and to reserve the E-type field existing in the existing Residential Ethernet header. And adds the length information of the transmission cycle through the area.

4 is a detailed structural diagram of one transmission cycle in a Residential Ethernet system according to the present invention.

Referring to FIG. 4, the Residential Ethernet transmission cycle proposed in the present invention comprises a superframe in which a transmission cycle of 125 microseconds is multiplied by a predetermined multiple, and each superframe has an asynchronous An asynchronous area 32 for transmission of data and a synchronous area 31 for transmission of synchronous data.

In more detail, the synchronization area for transmission of synchronization data is the highest priority part in the transmission cycle. In the embodiment according to the present invention, the cycle start frame 41, the plurality of synchronization packets 42-1 and 42-2 , And 42-3 and a synchronization end frame 43. [

The plurality of synchronization packets 42-1, 42-2, and 42-3 according to the embodiment of the present invention are made up of normal Ethernet packets and there is no way to indicate that the synchronization subframe is a synchronous subframe. The start of the synchronization area is notified only through the cycle start frame 41 and the end of the synchronization area is notified through the synchronization end frame 43 so that the frames existing therebetween can be displayed as a synchronization packet.

In the Residential Ethernet transmission cycle according to the embodiment of the present invention, the sub-synchronous packet includes the Multi-Payload in the existing Residential Ethernet transmission cycle, while the independent packets 42-1, 42-2, 42- 3) each include an independent payload having a single destination address. Therefore, in the embodiment of the present invention, an ordinary Ethernet packet is used as a sub-sync packet.

In order to provide such a synchronization packet, in the embodiment of the present invention, a special frame is generated as if it is a beacon frame of a wireless LAN to announce the start of the synchronization area. A frame similar to this beacon frame is referred to as a cycle start frame 41.

The cycle start frame 41 includes a DA field 401 for displaying a destination address, an SA field 402 for displaying a source address, an E type field 403 for displaying an Ethernet type, A flag field 404 for indicating whether or not the current cycle is a cycle, a cycle duration field 405 for indicating a cycle duration, that is, a cycle, a cycle number Number field 406 and an FCS field 408 for detecting a transmission error of the frame.

In addition, it further includes a Sync Duration field 407 for indicating where the Sync area is. At this time, if the sync duration field 407 is included in the cycle start frame 41, the sync end frame 43 can be removed. This is because the synchronous duration field 407 indicates the size of the synchronous area, so that it is possible to know the end of the synchronous area without displaying the end of the synchronous area using the synchronous end frame 43. [

On the other hand, the asynchronous area is composed of a plurality of asynchronous packets 44. Here, the asynchronous packet 44 may be referred to as a "Best Effort frame" since all packets are processed in the same way by routers according to a route determined by a routing protocol.

FIG. 5 is a flowchart illustrating a method of setting a transmission cycle for accommodating Fast Ethernet in Residential Ethernet according to an embodiment of the present invention. Referring to FIG.

Referring to FIG. 5, a predetermined sync packet is received and a super frame of 125? S is formed (51). If it is confirmed that there is a synchronous packet or an asynchronous packet to be transmitted through the super frame of the configured 125 μs and the synchronous packet or the asynchronous packet is included in the corresponding super frame of 125 μs, And performs residential Ethernet data transmission using the frame (53).

Here, it is checked whether there is a synchronous packet or an asynchronous packet to be transmitted through the configured super frame of 125 μs, and a step 52 of confirming whether the synchronous packet or the asynchronous packet can be included in the corresponding super frame of 125 μs , And generally whether the transmission area for the asynchronous packet remains. That is, it determines the extension of the superframe through whether a transmission region for at least one asynchronous packet can be allocated in one transmission cycle.

On the other hand, if it is determined that there is no synchronous packet or asynchronous packet to be transmitted through the superframe of 125 microseconds and the corresponding synchronous packet or asynchronous packet can not be included in the superframe of 125 microseconds (52) In a super frame of 125 μs (54). Then, information on a predetermined multiple set is inserted into the header of the generated super frame (55). Then, Residential Ethernet data transmission using a superframe of a predetermined multiple of 125 microseconds is performed (56).

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. The present invention is not limited to the drawings.

As described above, the present invention solves the efficiency problem of data transmission that can occur when Fast Ethernet is accommodated in a Residential Ethernet and assures QoS, so that general Ethernet and Residential Ethernet can be efficiently interworked .

Claims (7)

A method for setting a transmission cycle for data transmission in a Residential Ethernet device capable of efficiently providing a real-time service and a non-real-time service simultaneously using Ethernet, A first step of receiving a synchronous packet for the real-time service and an asynchronous packet for the non-real-time service and generating a super frame according to a reference transmission cycle; A second step of checking whether at least one asynchronous packet is included in the super frame generated in the first step; A third step of generating a second super frame in which the super frame is extended by a predetermined multiple if at least one asynchronous packet is not included in the super frame as a result of the second step; And And a fourth step of inserting the predetermined multiple information into a header of the generated second super frame to transmit data through the second super frame. The method according to claim 1, Wherein the reference transmission cycle has a time interval of 125 占 퐏. 3. The method according to claim 1 or 2, Wherein the predetermined multiple is an integer multiple of 4 or less. 3. The method according to claim 1 or 2, Wherein the predetermined multiple is 2n (where n is an integer) times the transmission speed. 3. The method according to claim 1 or 2, Wherein the predetermined multiple is 2 &^lt; ⁿ > (where n is an integer) times the transmission rate. 3. The method according to claim 1 or 2, In order to insert the predetermined multiple information into the header of the generated second super frame, Type field in the header of the second super frame is used as the reserved area of the E-type field in the header of the second super frame. 3. The method according to claim 1 or 2, In order to insert the predetermined multiple information into the header of the generated second super frame, And a field for inserting the predetermined multiple information in a header of the second super frame is included in the header of the second super frame.

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