Patent Description:
Ultrafast communication is highly important in many fields, for example in the field of trading. In trading, a so-called liquidity provider has a risk of adverse selection. When the price of a product on a market changes, a liquidity provider will desire to update its active bids and offers on the market as quickly as possible to prevent that deals are made based on the "old" prices, which may cause losses. In light of this, it is of no surprise that liquidity providers have a desire to communicate with an exchange as fast as possible.

<CIT> discloses a low-cost, high-bandwidth file server, which is implemented in a single integrated semiconductor. High-bandwidth is achieved through the use of a shared memory buffer, protocol aware logic, and a modified network stack. The shared memory buffer allows data flow from the network to the storage device without the need of a single copy.

The paper "<NPL>), discloses parallel header processing in an all optical switch. This paper discloses the header and payload being transmitted separately in the system enabling parallel processing and reducing the amount of buffering.

<CIT> discloses a system that receives a line encoded data stream from a source. The system has a de-serializer for de-serialising the line encoded data stream to generate a raw parallel data stream. The system has a serializer for serialising the raw parallel data stream. The system has a parallel data generator configured to generate another raw parallel data stream. The system has reconfigurable circuitry for communicating raw parallel data stream to the serializer in a configuration and communicating the other parallel data stream in another configuration.

Of course, trading is just one many fields that may benefit from ultrafast communication. Hence, there is a need in the art for methods and systems that enable fast communication.

To that end a method is disclosed for transmitting a response message in response to a an incoming message. The incoming message comprises a header portion and a payload and the response message also comprises a header portion and a payload. The header portion of the incoming message is identical to the header portion of the response message. The payload of the incoming message is different from the payload of the response message. The method comprises receiving an incoming physical signal representing the incoming message. This step comprises receiving a header part of the incoming physical signal, the header part representing the header portion of the incoming message, and thereafter receiving a payload part of the incoming physical signal, the payload part representing the payload of the incoming message. The method also comprises splitting the incoming physical signal into a first copy of the incoming physical signal and a second copy of the incoming physical signal. The method further comprises providing the first copy of the incoming physical signal to a transmitter system so that at least part of the first copy's header part is transmitted. The method further comprises interpreting at least part of the second copy of the incoming physical signal to determine that a message is received. Further, the method comprises generating a signal and, based on determining that a message is received, providing the generated signal to the transmitter system so that the generated signal is transmitted after the at least part of the first copy's header part has been transmitted. Herein, the transmitted at least part of the first copy's header part and the transmitted generated signal together form a transmitted response signal representing the response message.

One aspect of this disclosure relates to a system for transmitting a response message in response to a an incoming message. The incoming message comprises a header portion and a payload. The response message also comprises a header portion and a payload, wherein the header portion of the incoming message is identical to the header portion of the response message. The system comprises an input for receiving an incoming physical signal representing the incoming message. The incoming physical signal comprises a header part, the header part representing the header portion of the incoming message, and a payload, the payload part representing the payload of the incoming message. The system further comprises a transmitter system for transmitting a transmitted response signal representing the response message. Further, the system is configured to.

This method and system enable to send out a response message very fast in response to an incoming message. The inventors have realized that if the header parts of the incoming message and the response message are identical, then the header part of the incoming physical signal can be directly sent, preferably without any interpretation of the header part of the incoming physical signal, to a transmitter system that can directly transmit back the header part of the incoming physical signal as header part of the response signal. In this way, by the time that the system determines, based on the second copy of the incoming physical signal, that a message is received, at least a part of the header part of the response signal, which header part represents the header portion of the response message, will already have been transmitted. At some point, the first copy of the incoming physical signal should not be transmitted anymore, else merely a copy of the incoming message will be transmitted as response message, which is not the aim of this method. Hence, the method comprises generating a signal, part of which may be determined based on the payload of the incoming message, and providing this generated signal to the transmitter system in such manner, e.g. with such timing that the already transmitted part of the first copy of the incoming physical signal and the generated signal together form a valid transmitted response signal representing the response message. In any case, since at least part of the header part of the incoming physical signal is directly used for transmission, the response message will have been completely transmitted at an earlier time than would be the case if the header part of the response signal would have been generated by the system itself. Generating a signal namely takes time.

Any portion of the incoming message that differs from any portion of the response message may be understood as belonging to the payload of the incoming message. Further, any portion of the response message that differs from any portion of the incoming message may be understood as belonging to the payload of the response message.

The system may comprise one or more elements to amplify and/or denoise the incoming and outgoing physical signals or its copies. Such amplification and/or denoising may serve to ensure signal integrity when the signal is sent by the transmitter system. To this end, also a filter may be implemented in the system. The amplifiers and filters depend on the signal method and physics.

The incoming message may come from a computer system of an exchange and the payload of the incoming message may indicate market information. Similarly, the payload of the response message may be transmitted by a computer system of a trading company in which case the payload of the response message typically comprises updates to bid and/or offer prices.

It should be appreciated that since the incoming physical signal comprises the header part representing the header portion of the incoming message, the first copy also comprises this header part.

The incoming physical signal may represent a bit stream.

A physical signal as used herein may be understood to refer to variations, preferably variations in time, of a physical quantity wherein the variations are used to convey information. Typically, a transmission medium carries such variations from a sender device to a receiver device. A physical signal is for example formed by voltage variations in an electrical conductor and/or for example formed by variations of light intensity of light travelling through an optical conductor, such as an optical fiber cable. As used herein, a part of a signal may refer to some time period in which variations forming the signal are occurring, however, wherein variations forming the signal are also occurring outside of this time period.

Also, if a physical signal refers to variations of a physical quantity, then a copy of this physical signal may be understood to refer to the same variations of the same physical quantity.

As used herein, interpreting a physical signal may be performed by quantizing the signal and/or sampling the signal. In case both quantization and sampling are performed, interpreting a physical signal may be understood to be performed by converting the physical signal into a digital signal. Sampling may be understood as reducing a continuous-time signal to a discrete-time signal. Quantizing may be understood as mapping input values from a first, typically continuous, set of values to output values in a (countable) smaller set. In case the incoming physical signal represents a bit stream, quantizing may be understood to comprise mapping input values, e.g. light intensity values in case of an optical signal, to a "<NUM>" value or a "<NUM>" value.

Deserialization may be understood as the process of reconstructing a data structure or object from a signal, e.g. a signal representing a series of bytes or a string, in order to instantiate the data structure or object. This is the reverse process of serialization, i.e., converting a data structure or object into a signal, e.g. into a series of bytes, for storage or transmission across devices. It should be appreciated that deserializing a signal requires interpreting the signal, because the transformation from serial to parallel requires knowledge of the different values represented by the signal. Also, any logical operations that are to be performed based on a signal, such as determining a payload for the response message based on the incoming physical signal, requires interpretation of the incoming physical signal.

Interpreting a signal thus optionally comprises deserializing the signal. Additionally or alternatively, interpreting a signal optionally comprises decoding the signal.

Once a signal has been interpreted, e.g. converted into a digital format, information, a data structure or object may be reconstructed based on the digital signal.

The incoming message as well as the response message may be embodied as an Ethernet packet, as for example defined in standard IEEE <NUM>-<NUM> - IEEE Standard for Ethernet. In such case, the header portion of the incoming and response message may be the seven-octet Ethernet packet preamble, which is the same for every Ethernet packet. Preferably, the response message and the response signal comply with the IEEE standard for <NUM>-BASE-LR, in particular with the IEEE Standard for Ethernet <NUM> section <NUM>.

The generated signal optionally comprises a header part that represents at least a part of the header portion of the response message. This may be required if for example the generated signal is provided to the transmitter system before the entire first copy's header part has been transmitted by the transmitter system by means of transmitting the first copy. If the complete header part representing the header portion of the response message has not been transmitted yet, then still a remaining header part should be transmitted. This remaining header part should then be present in the generated signal.

The generated signal typically comprises a payload part representing the payload of the response message.

The method may comprise, and the data processing system of the system may be configured for, determining that a message is received based on a header part of the interpreted signal representing the header portion of the incoming message, e.g. the Ethernet preamble referred to above. For example, the data processing system may be configured to detect Ethernet preambles in order to determine that a message is being received.

Of course, the incoming physical signal may be split into further copies as well, for example into a third copy, fourth copy, et cetera.

In an embodiment of the method (i) the incoming physical signal is not interpreted before splitting the incoming physical signal into the first copy and second copy, and/or (ii) splitting the incoming physical signal does not involve interpreting the incoming physical signal, and/or (iii) the first copy of the incoming physical signal is not interpreted before and not interpreted during transmitting the at least part of the first copy's header part.

In an embodiment of the system, the system is configured to.

These embodiments allow to directly send back at least the header part of the incoming physical signal without losing any time for interpreting the signal and thus enables very fast responses. Such interpretation typically involves converting the incoming physical signal into a digital format which takes more time than not interpreting.

Thus, in these embodiments, the physical signal is typically not quantized and/or not sampled and/or not digitized and/or not deserialized.

In an embodiment of the method, the generated signal comprises a predefined part that has already been defined before determining that a message is received, said predefined part of the generated signal being generated based on prestored data representing at least part of the response message's payload.

In an embodiment of the system, the data processing system comprises a storage medium having stored thereon - already before the data processing system determines that a message is received - data representing at least part of the response message's payload. In this embodiment, the data processing system is configured to generate the signal based on the prestored data.

To illustrate, this predefined part may be a part of the response message that indicates the destination and/or source address for the response message. The destination address may be known beforehand, for example. Upon determining that a message is received, yet without having inspected the payload of the incoming message, the system can already generate the predefined part of the response signal, e.g. the part that represents the destination address for the response message.

As explained above, the response signal may comprise a payload part representing the payload of the response message. The predefined part of the generated response signal may comprise a predefined payload message part, which predefined payload part represents a predefined part of the payload portion of the response message. Additionally or alternatively, the predefined part of the generated response signal may comprise a part representing at least part of the header portion of the response message.

This embodiment is especially advantageous in case the predefined part of the generated signal comprises a predefined payload part representing a predefined part of the response message's payload part, e.g. indicating a default destination address for the response message. This namely allows to already transmit this predefined part of the serialized signal while the payload of the incoming message is still being received and processed, e.g. while a payload of the response message is still being determined. The transmittal of the predefined payload part may be understood to give the data processing system more time to determine an appropriate payload for the response message based on the payload of the incoming message.

It should be appreciated that it is not per se required that the generated signal comprises a predefined part.

In an embodiment, the method comprises interpreting at least part of the second copy of the incoming physical signal to determine at least part of the incoming message, and determining, based on the determined at least part of the incoming message, at least part of the payload of the response message. Likewise, in an embodiment of the system, the data processing system is configured to determine at least part of the incoming message, and to determine, based on the determined at least part of the incoming message, at least part of the payload of the response message.

In an embodiment, the method comprises interpreting at least part of the second copy of the incoming physical signal to determine at least part of the header and/or at least part of the payload of the incoming message, and determining, based on the determined at least part of the header and/or the determined at least part of the payload, at least part of the payload of the response message. Likewise, in an embodiment of the system, the data processing system is configured to determine at least part of the payload of the response message based on the interpreted part of the second copy of the incoming physical signal.

These embodiments allows the system to base its response on the contents of the payload of the incoming message.

In particular, it may be understood that, in these embodiments, the generated signal is generated based on the determined payload of the response message.

Each of the incoming physical signals, the first and second copy of the incoming physical signal, the generated signal and the transmitted response signal may be a physical signal representing a bit stream.

In an embodiment, the method comprises synchronizing the generated signal to the first copy of the incoming physical signal.

In an embodiment of the system, the system is configured to synchronize the generated signal to the first copy of the incoming physical signal. To this end, the system may comprise a delay line for delaying the provisioning of the first copy to the transmitter system.

This embodiment enables to accurately line up the first copy of the incoming physical signal and the generated signal together to from the response signal representing the response message in such manner, that the response signal, which may be understood to be a combination of the first copy of the incoming signal and the generated signal, represents a proper signal to the receiver. A proper signal may be understood to refer to a signal which the receiver of the signal can interpret, adhering to all requirements stemming from the receiver's specifications. An example of this could be ethernet over optical fiber.

In an embodiment, the method comprises, based on determining that a message is received, switching from (i) providing the first copy of the incoming physical signal to the transmitter system to (ii) providing the generated signal to the transmitter system.

In an embodiment of the system, the system further comprises a switch for controlling whether or not the first copy of the incoming physical signal is provided to the transmitter and for controlling whether or not the generated signal is provided to the transmitter system. In such embodiment, the data processing system may be configured to cause the system to provide the generated signal to the transmitter system by sending a control signal to the switch.

The switch may be configured to select either one of providing the first copy or the generated signal to the transmitter system for transmittal.

In these embodiments, it may be understood that, after the switch, the generated signal is provided to the transmitter system instead of the first copy.

The switch needs to be suitable for the physical medium of the signals, e.g.: single ended electrical, balanced electrical, optical, pressure in any matter phase state, neutrinos, tachyons etc. Any type of switch can be selected as long as it can control whether or not the first copy of the incoming physical signal is provided to the transmitter and whether or not the response generated signal is provided to the transmitter system.

The switch may be a switch system in the sense that it may comprises several sub-switches, for example a first sub-switch for controlling whether or not the first copy of the incoming physical signal is provided to the transmitter system and a second sub-switch for controlling whether or not the generated signal is provided to the transmitter system.

Preferably, the switching is performed such that the transmitted response signal does not comprise interruptions which cause receiving errors at a receiving system that receives the response signal. Thus, preferably, the switch is configured to switch such that the transmitted response signal can be correctly interpreted by a receiver, e.g. such that it does not comprise interruptions which cause receiving errors at a receiving system that receives the response signal.

Preferably, the generated signal is synchronized, e.g. bit aligned, with the incoming signal such that the transmitted response signal can be correctly interpreted by a receiver. To this end, the method may comprise synchronizing, e.g. bit aligning, the generated signal with the incoming signal.

The incoming physical signal may be an electrical signal. The incoming physical signal may be a light signal. The incoming physical signal may be a sound signal.

As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, a method or a computer program product.

A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as portion of a carrier wave.

Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages.

In one aspect, embodiments of the present invention may relate to a computer-implemented method for determining that a message is received.

A computer program may, for example, be downloaded (updated) to the existing systems or be stored upon manufacturing of these systems.

Embodiments of the present invention will be further illustrated with reference to the attached drawings, which schematically will show embodiments according to the invention. It will be understood that the present invention is not in any way restricted to these specific embodiments.

In the figures, identical reference numbers indicate identical or similar elements.

<FIG> schematically show a system for transmitting a response message in response to an incoming message according to an embodiment. <FIG> also schematically illustrate a method for transmitting a response message in response to an incoming message according to an embodiment in that <FIG> illustrate different states of the system <NUM> while the method according to an embodiment is performed.

The system <NUM> in <FIG> comprises an input <NUM> for receiving an incoming physical signal. The input <NUM> may be an input port, for example. However, the input may also simply be the place where the incoming physical signal enters the system <NUM>. This signal may be an electrical signal or an electromagnetic signal, such as a light signal. An electrical signal may use current and/or voltage variations in order to convey information. An electromagnetic signal may use variations in radiant power of electromagnetic radiation, such as variation in light intensity, in order to convey information. The incoming physical signal may be provided to the system via electrical conductors in the case of electrical signals and via optical conductors, such as optical fiber cables, in the case of electromagnetic signals. The incoming physical signal may be a bit stream. Such bit stream may represent an ethernet packet.

The incoming physical signal represents the incoming message <NUM>. This may be understood as that the incoming signal conveys information based on which the incoming message can be reconstructed. The incoming message <NUM> comprises a header portion <NUM> and a payload <NUM>. In <FIG>, the header portion comprises, for illustrative purposes, three bits A, B and C, and the payload <NUM> comprises six bits D, E, F, G, H, I. Thus, it should be appreciated that the incoming physical signal comprises a header part representing the header portion <NUM> and a payload part representing the payload <NUM>. The header part of the incoming physical signal is received before the payload part.

The system <NUM> further comprises a splitter <NUM> for splitting the incoming physical signal into a first copy and a second copy, a transmitter system <NUM> for transmitting transmitted response signal representing the response message, a switch <NUM>, a data processing system <NUM>. The transmitter system <NUM> may be an output port of the system <NUM>. However, the transmitter system may also simply be embodied for example as optical wires and/or electrical wires that lead the convey the response signal out of the system <NUM>.

In the depicted system, the data processing system <NUM> is shown to comprise a deserialization module <NUM>, which is configured to interpret at least part of the second copy of the incoming physical signal, in particular to deserialize the second copy of the incoming physical signal. The deserialization module <NUM> is preferably also configured to convey information to the logic <NUM> in a form which the logic <NUM> can process. The deserialization module <NUM> may for example be configured to digitize the second copy of the incoming signal, and thus to determine a digital signal based on the second copy of the incoming physical signal and then to convey this digital signal to the logic <NUM> in a form which the logic <NUM> can process.

In the depicted system, the data processing system <NUM> is shown to comprise a serialization module <NUM> which is configured to serialize a part of the response message as determined by the data processing system <NUM> in order to generate the signal, also referred to herein as the "generated signal".

<FIG> further shows that the data processing system has stored data <NUM> which, as will be explained later, will turn out to be data <NUM> representing at least part of the response message's payload. It should be appreciated that this pre-stored data is optional. There may be no pre-stored data. The pre stored data <NUM> may be used to generate part of the response signal. Data <NUM> may be stored on non-transitory computer readable storage media (not shown) of data processing system <NUM>.

<FIG> illustrates that the system <NUM> is configured to split the incoming physical signal into a first copy <NUM> of the incoming physical signal and a second copy <NUM> of the incoming physical signal. Any suitable element that can split the incoming physical signal may be used, given a certain type of incoming physical signal. In case the incoming physical signal is an electrical signal then the splitter <NUM> may comprise a buffer, for example, to split the incoming electrical signal into a first copy and second copy. In case of optical signals, such splitting of the signal may be performed by using optical splitters known in the art. The first and second copy of the incoming physical signal may still represent bit streams once they are interpreted. Also, it should be appreciated that the splitting does not involve interpreting the incoming physical signal and thus does not involve any deserialization.

<FIG> illustrates that the first copy <NUM> is provided to the transmitter system <NUM> so that at least part of the first copy's header part is being transmitted. In the depicted example, the entire header part, representing bits A, B, C is provided to the transmitter system <NUM> and thus transmitted. In the depicted example, no interpretation of the first copy of the incoming physical signal is performed, thus also no deserialization is performed on the first copy of the incoming physical signal. The incoming physical signal is thus directly fed back to the transmitter system <NUM> so that it is transmitted. In the depicted example, the first copy <NUM> is provided to the transmitter system <NUM> via switch <NUM>.

<FIG> further shows that the second copy <NUM> of the incoming physical signal is provided to data processing system <NUM>, in particular to a deserializer module <NUM> that will interpret, in particular deserialize, the incoming physical signal. After at least part of the second copy <NUM> has been interpreted, it is provided to logic <NUM>, which is configured to determine that a message is received. The logic <NUM> is for example configured to recognize a bit pattern as a header portion of an incoming message. It should be appreciated that for the logic <NUM> to determine that a message is received, it is not necessary that the entire second copy of the incoming physical signal is interpreted.

<FIG> illustrates that the module <NUM> has deserialized the second copy of the incoming physical signal <NUM>. The data processing system <NUM> can determine, based on the interpretation of the second copy of the incoming signal, that a message is received.

Based on determining that a message is arriving, the data processing system <NUM> may start to generate a signal. In any case, based on determining that a message is received, the data processing system <NUM> may cause a switch from (i) providing the first copy of the incoming physical signal to the transmitter system to (ii) providing the generated signal to the transmitter system <NUM>. The data processing system <NUM> is configured to control the switch <NUM> as indicated by the arrow from data processing system <NUM> to the switch <NUM>.

The generated signal in the depicted example represents the payload <NUM> of the response message <NUM> (also see <FIG>). In this example, the generated signal comprises a predefined part that has already been defined before determining that a message is received, namely a part generated based on prestored data <NUM>. This part represents part of the payload <NUM> of the response message <NUM>. In the depicted example, this part of the payload which is predefined consists of bits J, K, L. It should be appreciated, however, that the pre-stored data <NUM> and the predefined part are optional.

In <FIG>, the data processing system <NUM>, in particular the logic <NUM>, determines, based on the interpreted second copy of the incoming physical signal, a part <NUM> of the payload <NUM> of the response message <NUM>. In the depicted example, this part of the payload that is determined by the data processing system <NUM> consists of bits M, N, O. In this example, part <NUM> is determined based on an at least partially determined header and/or on an at least partially determined payload of the incoming message. However, it should be appreciated that the system can also determine at least part of the payload, or the entire payload, of the response message without knowing what bits are in the header or payload of the incoming message. In an example, if the data processing system is unable to determine the bits of the header and/or payload, e.g. due to noise, it will determine a default payload of the response message, for example, which indicates that a message was not well-received.

The data processing system <NUM> may be understood to generate the signal by first determining the payload portion <NUM> (<FIG>) of the response message and then generating the signal representing this determined payload portion <NUM>. In particular, the generated signal may be generated by a serialization module <NUM> as shown. It should be appreciated that the data processing system may generate multiple signals, optionally based on the contents of the incoming message, after which the data processing system selects one of these multiple generated signals in order to provide the selected signal to the transmitter system. In such case, the data processing system may comprise multiple parallel signal generators.

The switch <NUM> is controlled such that right after the header part of the response signal representing bits A, B, C has been transmitted, the generated signal representing bits J, K, L, M, N, O are transmitted. To this end, the system may be configured to synchronize the generated signal to the first copy of the incoming physical signal. These signal are aligned in such a way that to the receiver it is interpretable. It should be appreciated that, for clarity, <FIG> depicts bits Land M separately from each other, however, they are transmitted back-to-back as shown in <FIG> such that in the response message, bit M follows bit L in manner compliant with the applicable transmission protocol.

In order to get the timing correct of the generated signal as well as the timing of the switch, the data processing system <NUM> may receive a copy of the transmitted response signal from the transmitter system <NUM>. (This is not shown in <FIG>. ) The data processing system <NUM> can then determine whether the transmitted response signal is correct, for example whether it complies with message protocols as desired, for example with the ethernet protocol. If this is not the case, then the timing of the switch and/or the timing of the generated signal may have to be adapted.

Getting the timing right may be performed using test signals as incoming physical signals to which the system <NUM> should respond with a test response message. For example, if it turns out, upon analysis of the transmitted test response message, that the switch switches over from the first copy of the incoming physical signal to the generated signal too fast so that bits are missing in the test response message, the data processing system may be programmed to cause the switch to switch at a later time.

In an embodiment, a calibration may be performed for determining a correct timing for the generated signal and the switch. In such calibration, a test incoming signal, representing a test message may be input into the system. Then, a copy of the incoming signal (not the first copy or second copy described herein but a third copy) may be provided to a detector, whereas the second copy of the incoming signal is provided to a data processing system for interpreting the signal. The data processing system then detects that a message is received, determines a payload for a test response message and generates a test signal and provides this generated test signal to the detector as well. The detector can then compare the test incoming physical signal and the generated test signal in order to synchronize, e.g. bit align, these signals. The data processing system then may adjust its time delay to synchronize the signals. This time delay would then also be used by the data processing system in operation.

After performing such calibration, the data processing system knows upon detecting that an incoming message is received, when it needs to cause a switch from the first copy of the incoming physical signal to the generated signal. The data processing system may then also know which bit should be provided first by means of the generated response signal. Thus, after such calibration, the data processing system may have stored information indicating, at which particular time after detecting that an incoming message is received, the data processing system has to start generating the signal and when to cause a switch from the first copy to the generated signal, and preferably also information indicating that the first bit in the response signal that is represented by the generated signal, is the nth bit of the response message, n being an integer number.

<FIG> illustrates that the data processing system <NUM>, based on determining that a message is received, has provided the response signal (bits J, K, L M, N, O) to the transmitter system <NUM> in such manner that the response signal is transmitted after the at least part of the first copy's header part has been transmitted, and such that the transmitted at least part of the first copy's header part (bytes A, B, C) and the transmitted generated signal together form a transmitted response signal representing the response message <NUM>. The transmitted response signal may also represent a bit stream.

As is clear from a comparison of <FIG> and <FIG>, the response message <NUM> comprises a header portion <NUM> and a payload <NUM>, and the header portion <NUM> of the incoming message <NUM> is identical to the header portion <NUM> of the response message <NUM>. In this example, both header portions consist of bits A, B, C. In contrast, the payload of the response message <NUM> differs from the payload <NUM> of the incoming message <NUM>.

It should be appreciated, however, that the system <NUM> is also able to send back a response message that is identical to an incoming message. When this happens, the switch <NUM> simply does not switch. In an example, the data processing system <NUM> may interpret at least part of a second copy of some incoming physical signal to determine at least part of an incoming message, e.g. at least part of a header and/or a payload, and may refrain from causing the switch <NUM> to switch based on the determined at least part of the incoming message.

<FIG> clarifies a distinction between processing of a physical signal and of a logical message. In <FIG>, the physical signal is shown to arrive at the signal splitter <NUM>, which splits the physical signal into a first copy <NUM> and a second copy <NUM>. This split may be understood to occur in the physical layer, which is conceptually shown as the area below line <NUM>. No interpretation of the physical signal is required for splitting the signal.

<FIG> illustrates that the second copy <NUM> of the physical signal is interpreted in the sense that it is decoded. This allows to determine the incoming message, process it, and allows to determine contents of a response message. These steps may be understood to be performed on a logical level which is conceptually indicated by the area above line <NUM>.

In the depicted embodiment, after at least part of the response message has been determined, a physical signal is generated again which can be provided to the switch <NUM>. The switch <NUM> may be controlled by control signals determined during or after the processing of the response message, as shown.

The switch <NUM> may switch, as described herein, between providing the first copy and providing the second copy to a transmission system. The switching itself, as shown, may be understood to occur again in the physical layer, thus without requiring interpretation of the physical signals.

It should be noted that in the embodiment of <FIG>, the first copy <NUM> of the physical signal remains in the physical level and is thus not interpreted before it is provided to the transmission system.

<FIG> depicts a block diagram illustrating a data processing system according to an embodiment.

Examples of input devices may include, but are not limited to, a keyboard, a pointing device such as a mouse, a touch-sensitive display, an input <NUM> receiving the incoming physical signal, or the like. Examples of output devices may include, but are not limited to, a monitor or a display, speakers, the switch <NUM> described herein, the transmitter system <NUM> described herein, or the like.

In various embodiments, the application <NUM> may be stored in the local memory <NUM>, the one or more bulk storage devices <NUM>, or apart from the local memory and the bulk storage devices.

Claim 1:
A method for transmitting a response message (<NUM>) in response to an incoming message (<NUM>), wherein
the incoming message (<NUM>) comprises a header portion (<NUM>) and a payload (<NUM>), wherein
the response message (<NUM>) also comprises a header portion (<NUM>) and a payload (<NUM>), wherein
the header portion (<NUM>) of the incoming message (<NUM>) is identical to the header portion (<NUM>) of the response message (<NUM>), wherein
the payload (<NUM>) of the incoming message (<NUM>) is different from the payload (<NUM>) of the response message (<NUM>), the method comprising
receiving an incoming physical signal representing the incoming message (<NUM>), this step comprising receiving a header part of the incoming physical signal, the header part representing the header portion (<NUM>) of the incoming message (<NUM>), and thereafter receiving a payload part of the incoming physical signal, the payload part representing the payload (<NUM>) of the incoming message (<NUM>), and
splitting the incoming physical signal into a first copy of the incoming physical signal and a second copy of the incoming physical signal, and
providing the first copy of the incoming physical signal to a transmitter system (<NUM>) so that at least part of the first copy's header part is transmitted, and
interpreting at least part of the second copy of the incoming physical signal to determine that a message is received, and
generating a signal, and
based on determining that a message is received, providing the generated signal to the transmitter system (<NUM>) so that the generated signal is transmitted after the at least part of the first copy's header part has been transmitted, wherein the transmitted at least part of the first copy's header part and the transmitted generated signal together form a transmitted response signal representing the response message (<NUM>).