Concatenation of several ethernet frames into one ethernet message

The present invention relates to the field of communication technology.

Known radio systems, such as Wi-Fi (WLAN: Wireless Local Area Network) according to the IEEE 802.11 standard or the Bluetooth according to the standard IEEE 802.15.1, which allow a transparent transmission of Ethernet-based communication protocols, transmit these protocols highly inefficient because the Ethernet protocol is normally packed in a radio data packet without further optimization. Since the Ethernet packets according to the IEEE 802.3 standard must consist of at least 64 bytes, however, transferred many automation systems a few useful data bytes in an Ethernet data frames, the ratio of user data to protocol overhead or to the entire length of protocol in Ethernet systems adversely. This is even worse when a radio transmission, that a radio link has an even lower data rate as an Ethernet system. Furthermore, it must be additionally added a necessary for the communication protocol overhead for the radio link, which also can be transmitted only in a half duplex mode. Thus is the cycle time behavior of a radio-based Ethernet system t fundamentally disadvantageous compared to the time behavior of a wired Ethernet system such as the Profinet system.

A problem with known radio systems that often only a statistical media access is allowed. This creates disadvantages in the time behavior of an automation solution by, for example, increased jitter of the communication cycles. To optimize the time response polling-based media access method can be used for example, which are used in media access methods and which are allowed by default for WLAN in Bluetooth. However, even with these systems, only one data packet of an I / A-subscriber is transmitted per polling cycle. Being behind a wireless connection but multiple I / O devices that communicate cyclically for example in a network part fixed to a controller, so the timing of the entire communication between the I / O devices is not always predictable. So the Profinet standards, for example, ruled in a wireless transmission in the case that behind the radio bridge more than one I / O devices can be provided.

The <patcit><text>DE 10 2005 025 582 A1</text></patcit> relates to an apparatus and method for the combined transmission of data, an Ethernet MAC frame (MAC: Medium Access Control) is transmitted as a telegram via an Ethernet network.

The <patcit><text>US 2005/0018670 A1</text></patcit> discloses a method of forwarding frames between Ethernet network points, in which several packages are combined for transmission to a frame.

The post-published document <patcit><text>DE 10 2007 004 044 A1</text></patcit> relates to a Profinet transmission concept.

The <patcit><text>EP 1594284 A2</text></patcit> describes a process for the MAC header compression in the summary of data frames.

It is the object of the present invention to provide an improved concept for Ethernet transmission especially for Profinet systems.

This object is solved by the features of the independent claims.

According to several real-time Ethernet telegrams, for example, several real-time Profinet telegrams z. B. can be compressed to a 64 byte frame length by removing a padding wherein multiple Ethernet data frames, in particular several Profinet data frames are combined into a common message can. Moreover, the medium access control header (MAC header) of the Ethernet frames, for example, the Profinet frames, can be greatly reduced since the wireless components either the MAC addresses of the parties to the communication I / O and control participants similarly can learn like a switch. In addition, this information may be notified in case of a Profinet system, for example through the Profinet engineering. In this example, a Profinet I / O device (I / O: Input / Output), or any management interface, such as SNMP (Simple Network Management Protocol) is used. For this, the devices involved may for example include a Profinet-compliant interface. Alternatively, any management interface such as SNMP can be used. Thus, no longer a standard compliant Profinet telegram is between organizations involved in the radio communications infrastructure components, such as access points or clients sent. Instead, a compressed protocol is used, which can consist of the individual records of several Profinet participants.

&lt;?page 3?&gt;Therefore, increased in a simple manner both the protocol efficiency of wireless communication and the timing issues multiple I / O devices can be avoided, for example behind a wireless bridge by transferring several Profinet telegrams within a telegram. The compressed and packed together Protocol invention is preferably used exclusively for radio communication. The combining or unpacking these telegrams is preferably carried out by the respective participating wireless device, so that the connection outside the radio cell as a normal Ethernet connection or as a normal Profinet connection is perceived. The inventive concept may be for all wireless technologies, such as WLAN or Bluetooth transmission, used. In order for the wireless connection to the general network traffic remains transparent, the mechanism of the invention can be preferably applied to the real-time Ethernet telegrams such as Profinet telegrams with the Ethernet-type designation 0x8892.

In one aspect, the invention relates to an Ethernet transmission method with the combination of at least two Ethernet data frames into a composite Ethernet message and transmission of the Ethernet telegram via a communications network.

According to one embodiment, the method comprises compressing the Ethernet telegram.

According to one embodiment, the composite Ethernet telegram includes padding, and wherein the padding is removed for the compression of the Ethernet telegram.

According to one embodiment, each Ethernet data frame includes a medium access control header, wherein a medium access control headers to at least one Ethernet data frame is removed from.

According to one embodiment, the message is transmitted using the Ethernet protocol via a communication network.

According to one embodiment, the Ethernet transmission method is a Profinet transmission method wherein the Ethernet data frames are Profinet data frames and wherein the Ethernet telegram is a Profinet telegram.

In one aspect, the invention relates to an Ethernet reception method comprising receiving an Ethernet telegram via a communications network, and extracting at least two Ethernet data frames from the Ethernet telegram.

According to one embodiment, the Ethernet reception method is a Profinet transmission method wherein the Ethernet data frames are Profinet data frames and wherein the Ethernet telegram is a Profinet telegram.

In one aspect, the invention relates to an Ethernet transmission device with a device for combining at least two Ethernet data frames to an Ethernet telegram and a transmitter for transmitting the Ethernet telegram via a communications network.

According to one embodiment, the Ethernet transmission device comprises a compressor for the compression of the Ethernet telegram.

According to an embodiment which is a Profinet transmission device, the Ethernet data frames are Profinet data frames and wherein the Ethernet telegram is a Profinet telegram.

In one aspect the invention relates to an Ethernet receiver device comprising a receiver for receiving an Ethernet telegram via a communications network and a processor for extracting at least two Ethernet frames from the Ethernet data telegram.

According to one embodiment, the Ethernet reception device is a Profinet reception device, the Ethernet data frames are Profinet data frames and wherein the Ethernet telegram is a Profinet telegram.

In one aspect the invention relates to a computer program for executing at least one process of the invention.

Additional embodiments will be explained with more detail in the accompanying drawing.

<figref idrefs="S12">1</figref> shows a block diagram of an Ethernet transmission apparatus having a device <figref>101</figref> for combining at least two Ethernet data frames into a composite Ethernet telegram and a transmitter <figref>103</figref> the transmission of the Ethernet telegram via, for example, a wireless communication network.

The transmitting apparatus may further include a compressor for the compression of the Ethernet telegram, the compressor, for example, takes out padding bit of the data frame or from the individual telegrams. The compressor can also be provided to use a data compression method for compressing the telegram. The compressor can each remove one or more Medium Access Control Headers from the data frame to compress the composite message further.

In the <figref idrefs="S12">1</figref> Transmission device shown is preferably a Profinet transmission device so that the data frames are Profinet data frames and the telegram is a Profinet telegram.