Optical communication channel management in data centers

Abstract

A communication system and a method, the communication system comprising: a transmitter comprising: an Electrical-Optical converter for converting light in accordance with an electric signal, thereby generating data-carrying light to be transmitted through an optic fiber; a message generation module for generating a message indicating channel information of the transmitter; and a non-invasive management agent (MA) for embedding the message into the data-carrying light at frequencies lower than a threshold, thereby creating a management channel over the light; and a receiver comprising: a non- invasive MA adapted to retrieve a second message embedded within light transmitted by a second transmitter, the second message indicating second channel information of the second transmitter; and a message retrieval module for retrieving the second channel information from the second message, wherein the second channel information is used for updating a configuration of the transmitter, and wherein the communication system is within a data center.

Description

OPTICAL COMMUNICATION CHANNEL MANAGEMENT IN DATA CENTERSTECHNICAL FIELD

[0001] The present disclosure relates to photonic systems in general, and to a method and system for managing a communication channel between servers, in particular.BACKGROUND

[0002] Photonics is the physical science of light (photon) generation, detection, and manipulation through emission, transmission, modulation, signal processing, switching, amplification, and sensing.

[0003] Photonic systems are gaining more and more popularity in all areas, such as but not limited to light detection, telecommunications, information processing, photonic computing, lighting, metrology, spectroscopy, holography, medicine (such as surgery, vision correction, endoscopy, health monitoring), biophotonics, military technology, laser material processing, art diagnostics, material processing, art diagnostics involving InfraRed Reflectography Xrays, UltraViolet fluorescence, XRF), agriculture, robotics, and others.

[0004] Some important uses of photonic systems include transmitting and receiving information, multiplexing and demultiplexing information, or the like. Photonic devices may include but are not limited to photo detectors including photo diodes or photo transistors, laser diodes, light-emitting diodes, solar and photovoltaic cells, displays and optical amplifiers. Other examples include devices for modulating a beam of light and for combining and separating beams of light of different wavelength.

[0005] The need for photonic devices arises from the limits and limitations of electronic devices. A first limit relates to the transfer rate of information, and is due to electron speed saturation. A second limitation arises from the high power consumption of electronic devices, and thus the generated heat, the footprint and cost of heat dissipation. The use of photonic devices provides for higher rates, with little heating, thus curing or easing these problems.

[0006] An optical switch is a multi-port network bridge, which connects multiple waveguides such as optic fibers to each other and controls data packets routing between inputs and outputs. Optical switches generally switch or modulate optical signals in accordance with electric input signals.

[0007] An optical switch may be implemented as co-packaged optics, comprising within the same package Electronic Integrated Circuits (EIC) and Photonic Integrated Circuits (PIC). Optical fibers and communication may be used inter-switch for connecting between switches, or intra-switch for connecting elements within the switch.

[0008] As any communication system, optical systems are required to comply with quality requirements, in particular Bit Error Rate (BER) wherein errors may be caused by the transmitting side, the receiving side, or the connecting media.

[0009] Of special importance is the area of communication, and in particular communication within data centers, which may amount to as much as 75% of the total volume of digital communication in the world.BRIEF SUMMARY

[0010] One exemplary embodiment of the disclosed subject matter is a communication system comprising: a transmitter comprising: an Electrical-Optical (E / O) converter for converting light received from a light source, in accordance with an electric signal received from a driver, thereby generating data-carrying light to be transmitted through an optic fiber; a message generation module for generating a message indicating channel information associated with the transmitter; and a non-invasive management agent adapted to embed the message into the data-carrying light at frequencies lower than a predetermined threshold, thereby creating a management channel over the data-carrying light; and a receiver comprising: a non-invasive management agent adapted to retrieve a second message embedded within light transmitted by a second transmitter through the optic fiber, the second message indicating second channel information associated with the second transmitter; a message retrieval module for retrieving the second channel information associated with the second transmitter from the second message; and a photo diode for converting the light received through the optical fiber into an electric signal, wherein the second channel information is used for updating a configuration of at least one member of the transmitter, and wherein the transmitter and the receiver are parts of a communication system within a data center. Within the communication system, the transmitter and the receiver are optionally implemented as a single device. Within the communication system, the message generation module and the message retrieval module are optionally comprised in a single Micro Controller Unit (MCU). Within the communication system, the transmitter optionally further comprises an equalizer adapted to mitigate channel impairments, the first MCU optionally sends instructions to the equalizer how to modify parameters of the transmitter in accordance with the channel information associated with the transmitter, and the second MCU optionally sends instructions to the equalizer how to modify parameters of the transmitter in accordance with the channel information associated with the second transmitter. Within the communication system, the equalizer is optionally a Continuous-Time Linear Equalizer (CTLE). Within the communication system, the equalizer is optionally an optical equalizer. Within the communication system, the receiver optionally further comprises a transimpedance amplifier (TIA) with equalizer adapted to mitigate channel impairments, wherein the first MCU sends instructions to the TIA and equalizer how to modifyparameters of the receiver in accordance with the channel information associated with the transmitter, and wherein the second MCU sends instructions to the TIA and equalizer how to modify parameters of the receiver in accordance with the channel information associated with the second transmitter. Within the communication system, the receiver optionally comprises an equalizer; and the second MCU optionally sends instructions to the equalizer how to modify parameters of the communication system in accordance with the channel information associated with the second transmitter. Within the communication system, the transmitter optionally comprises an optical equalizer, and the optical equalizer is optionally configured in accordance with instructions received from the first MCU and from the second MCU. Within the communication system, the receiver optionally comprises an optical equalizer, and the optical equalizer is optionally configured in accordance with instructions received from the first MCU and from the second MCU. Within the communication system, optionally the transmitter is provided by a first manufacturer and the receiver transmitter is provided by a second manufacturer, different from the first manufacturer. Within the communication system, the predetermined threshold is optionally between at most 12MHz. Within the communication system, the transmitter optionally comprises a driver for attenuating the electric signal to a level compatible with the E / O converter, and the receiver optionally comprises a transimpedance amplifier (TIA) for amplifying the electric signal.

[0011] Another aspect of the disclosure is a method for operating a communication system within a data center, the method comprising: converting by an E / O converter light received from a light source, in accordance with an electric signal received from a driver, thereby generating data-carrying light to be transmitted through an optic fiber; generating a message indicating channel information associated with a transmitter switch ; and embedding the message into the data-carrying light at frequencies lower than a predetermined threshold, thereby creating a management channel over the data-carrying light. The method can further comprise: retrieving by a receiver the message embedded within the data-carrying light; retrieving the second channel information associated with the transmitter from the message; and updating a configuration of at least one member of the receiver switch in accordance with the channel information associated with the transmitter. The method can further comprise updating a configuration of at least one member of the transmitter switch in accordance with the channel information associatedwith the transmitter. The method can further comprise equalizing the communication channel in accordance with channel information associated with the transmitter or the receiver. Within the method, the transmitter is optionally provided by a first manufacturer and the receiver transmitter is provided by a second manufacturer, different from the first manufacturer. Within the method, the predetermined threshold is optionally at most12MHz.THE BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0012] The present disclosed subject matter will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which corresponding or like numerals or characters indicate corresponding or like components. Unless indicated otherwise, the drawings provide exemplary embodiments or aspects of the disclosure and do not limit the scope of the disclosure. In the drawings:

[0013] Fig. 1 is a schematic block diagram of a communication channel, in accordance with existing technologies;

[0014] Fig. 2 is a schematic block diagram an implementation of a communication channel comprising Linear Drive Pluggable Optics (LPO) and Linear Receive Optics(LRO);

[0015] Fig. 3 is a schematic block diagram of a switch and optical module, in accordance with some exemplary embodiments of the disclosure; and

[0016] Fig. 4 is a schematic block diagram of another implementation of a switch and optical module, in accordance with some exemplary embodiments of the disclosure.DETAILED DESCRIPTION

[0017] It is estimated that up to 75% of the total digital communication in the world is within data centers. For example, a person issuing a query to a search engine may initiate a mesh of requests and responses between a plurality of servers, for collecting the required information. This stems, inter alia, from the significant growth of Al applications, including the usage of Large Language Models, or others, which require higher data rates and better performance communication links within the data centers.

[0018] Thus, the problem of ensuring quality transmission, and in particular compliance with a required Bit Error Rate (BER), is crucial to the operation of a data center. If the BER exceeds the acceptable threshold, communication is unreliable and data needs to be retransmitted, thus causing further degradation of the quality.

[0019] One major cause of quality degradation is the inability of the transmitter and the receiver to exchange data related to the transmission quality and conditions. Absent such information, the receiver and the transmitter cannot update their parameters efficiently according to the data of the other side, in order to provide efficient communication. Therefore, if any of the transmitter or receiver fails to comply with its requirements, the other side has no way of knowing this, such that it can attempt to compensate for the miscompliance and enable proper communication.

[0020] Thus, one technical problem of the disclosure is the need to exchange channel management information between the transmitter and the receiver and vice versa.

[0021] Current technologies use a Digital Signal Processor (DSP) on either side to accommodate disturbances in their respective channels, and to ensure acceptable BER, before the information is converted to light which is carried by an optic fiber between the sides.

[0022] However, the DSPs on both sides cannot exchange information, and their ability to ensure proper communication is thus limited. In addition, the cost and development effort and energy consumption of DSPs, which may amount to up to 60% of the energy consumption of the electrical part of the transmitter or receiver, are significant and are cost ineffective.

[0023] The problem becomes more critical in the emerging approaches of Linear Drive Pluggable Optics (LPO) and Linear Receive Optics (LRO).

[0024] LPO solutions eliminate DSP, and the channel equalization is completely moved to the drivers and Transimpedance Amplifiers (TIAs). In some LRO implementations, half DSP is used, i.e. is activated only at the transmission path.

[0025] These newer LPO and LRO technologies do not enable interoperability, such that the transmitter and receiver need to be compatible to properly set the configuration of the drivers and the TIA for equalizing the communication system for mitigating the real channel impairments. For example, these impairments can be related to the different trace lengths RF design or other vendor variations.

[0026] One technical solution provided by the disclosure comprises an optical module designed to modulate the information-carrying light to convey also management information related to the channel and the configuration and parameters of the transmitting side. The receiving side receives this information and can use the information to adapt its parameters when receiving and processing the actual data transmitted by the transmitter, and also when transmitting information to the other side.

[0027] In some examples, the management information may comprise any one or more parameters such as but not limited to: an identifier of the transmitter, physical parameters of the transmitter's ASIC and / or the serializer / deserializer, the transceiver's vendor, the ASIC vendor, RF losses between the and the driver, operation temperature, transmitted optical power, critical S (scattering) parameters of the channel, other parameters of the channel, whether the transmitter has a DSP and its type or capabilities, or the like.

[0028] The optical module may thus comprise a Management Agent (MA) configured to receive channel information from a Micro Controller Unit (MCU), and to convey the information related to the management of the channel on the same optical wavelength, over the same optical fiber used for the actual data transmission. The management information may be transmitted simultaneously with the actual data or at other times. The frequencies that are insignificant for the actual information to be transmitted may be used for the transmission of the management information. In some examples, the appropriate RF frequencies for the management data transmission may be determined based on analysis of the power spectral density of the actual data. In some examples, frequenciesbelow about 10MHz may be used for transmitting the management information. Thus, embedding the information is done in a “transparent” manner and does not decrease the light intensity and does not damage the transmitted information.

[0029] The MA can detect the intensity of the light through the waveguide without consuming any portion of the light from the waveguide. In addition, the same ports that are used for monitoring the optical intensity, may be used for applying an external modulated voltage to the MA, in order to change the refractivity index of the waveguide, it is appreciated that the modulated voltage applied to the MA should be in the frequency range that cannot affect the quality of the actual data, for example, below 10MHz.

[0030] Implementation details of an MA may be found in US2023 / 0185117 titled “Device and Method for Calibration, Monitoring and Control of the Integrated Photonic Systems”, fded on January 31, 2023 and assigned to the same assignee as the current application, incorporating in its entirety for all purposes.

[0031] Once the receiving side receives the light, it can retrieve the channel information embedded in the lower RF frequencies of the modulated light, which indicates the conditions, configuration and parameters of the transmitting side, analyze the transmitting channel information and adapt its settings and parameters accordingly, for optimal retrieval of the transmitted information and for further transmissions. The adapted parameters may include but are not limited the gain and to the driver and TIA registers, used for implementing different equalization functions.

[0032] It is appreciated that the roles of the transmitter and receiver may be reversed, thus, either side may perform the functions of both a transmitter and a receiver. Thus, once such information is available, the transmitter and the receiver can update their parameters to better accommodate the settings, configurations and parameters of the other side and exchange information efficiently.

[0033] One technical effect of the disclosure comprises the provisioning of a management channel between the transmitter and receiver for exchanging channel information such that the receiver side can accommodate its parameters and settings to comply with the transmitter for higher quality, and for better transmission when the roles change and the receiver becomes a transmitter.

[0034] Another technical effect of the disclosure relates to transmitting the management information by modulating the light at certain otherwise unused frequencies, thereby not changing the actual information transmitted and avoiding negative effect on the light intensity.

[0035] Yet another technical effect of the disclosure relates to the interoperability of switches. Using the disclosure, switches of different manufacturers can be used at either side of the communication, thereby increasing the flexibility of the data center management and reducing operational costs.

[0036] Referring now to Fig. 1, showing a communication channel , in accordance with existing technologies.

[0037] The communication channel comprises a transmitter- side switch 100 and a receiver-side switch 104. In some examples, transmitter-side switch 100 and receiverside server or switch 104 may be the same device, such that each is a transmitter and a receiver. It is appreciated that a data center may comprise tens or hundreds of thousands of switches.

[0038] Transmitter-side switch 100 may comprise application-specific integrated circuit (ASIC) 108 for receiving or generating the data to be transmitted. ASIC 108 may comprise or is otherwise electrically coupled with serializer / deserializer 112 for transforming the parallel data to be output into serial data (and vice versa).

[0039] The information is provided to DSP 116 for mitigation of channel impairments, thus ensuring proper operation of the channel, i.e., complying with the transmission requirements and in particular, providing acceptable BER.

[0040] The information may then be provided to driver / TIA120 for matching the signal level by the driver to a level that can be handled by optical module 124 for electrical-to- optical conversion of the signal. The signal may then be provided to optical module 124 which transforms it into light. The light is then transmitted through optic fiber 128 to receiver-side switch 104.

[0041] On receiver-side switch 104, the light is received by optical module 124 which transforms it into serial electric data. The signal may then be provided to driver and TIA 120 to be amplified by the TIA, such that DSP 116 can handle it.

[0042] DSP 116 on receiver-side switch 104 retrieves the data in accordance with its parameters and settings to accommodate the channel disturbances and provides the data to ASIC 108, which can comprise or be electrically coupled to serializer / desrializer 112 for transforming the serial data into parallel data.

[0043] It is appreciated that the DSP is costly, hard to develop, and a significant energy consumer therefore it is desirable to eliminate it.

[0044] Referring now to Fig. 2, showing an implementation of a communication channel comprising linear driver pluggable optics (LPO), in accordance with newer technologies.

[0045] The channel comprises a transmitter-side switch 200 and a receiver side switch 204. As above, transmitter-side switch 200 and receiver-side switch 204 may be the same device, such that each is a transmitter and a receiver.

[0046] This solution eliminates the DSP, such that the serial data on the transmitter side is provided to a driver and Continuous -Time Linear Equalizer (CTLE) 208, designed to update the channel parameters and thereby enhance the signal to mitigate the channel impairments.

[0047] The equalized signal may then be provided to optical module 124, for converting the electrical signal to an optical signal modulated in accordance with the enhanced signal.

[0048] The light may then be transmitted through optic fiber 128 to the receiving side.

[0049] The reverse process is performed at switch 204 at the receiving side, such that the optical module 124 converts the light into a serial electric signal.

[0050] The signal may then be amplified by TIA+EQ 212, and provided to ASIC 108 through serializer / deserializer 112.

[0051] While this solution is more cost-effective, it consumes less power than the solution shown in Fig. 1 due to the elimination of the DSP. However, absent the capability of information exchange between the transmitting and receiving sides, the difficulty remains to tune the driver and TIA parameters for optimal operation.

[0052] Yet another problem with this solution is the lack of interoperability between the transmitter and receiver. Thus, only switches of the same manufacture may exchange communication, which severely limits the ability of the data center management to make its operation more efficient and reduce the costs.

[0053] Referring now to Fig. 3, showing a block diagram of a switch and optical module, in accordance with some exemplary embodiments of the disclosure.

[0054] Switch 300 may be a receiver and / or transmitter. In the embodiment of Fig. 3, switch 300 is a receiver and a transmitter, but it is appreciated that the functionality can be distributed into two separate switches, wherein some of the components need to be duplicated.

[0055] Switch 300 may be operative in transmitting and receiving channel management information during data transmission, or separately from data transmission, for example during a handshake phase, occasionally or periodically transmitting information such as temperature or the like.

[0056] Switch 300 may comprise ASIC 108 which generates the data to be transmitted. ASIC 108 can comprise or be electrically coupled to serializer / deserializer 112 as in Figs. 1 or 2 above.

[0057] The serial signal may then be provided to driver and Continuous Time Linear Equalizer (CTLE)3O8. In some embodiments, the driver may match the voltage to a level which is acceptable to E / O converter 328, while the

[0058] CTLE may adapt the electrical signal according to the channel parameters and behavior. In some embodiments, CTLE may use one of a few predetermined registers to pre-distort the signal in accordance with the channel characteristics.

[0059] Since the disclosure provides information exchange between the transmitter and the receiver, the configuration of driver and CTLE 308 of the transmitter may change according to data obtained from the management channel transmitted from the receiving side (when the receiving side transmits data).

[0060] The signal may then be provided to E / O converter 328 for modulating the light received from light source 324, in accordance with the digital electrical signal. Light source 324 may be, for example, a laser continuous wave or pulsed light source.

[0061] In some embodiments, the electrical signal can be an analog signal.

[0062] In some embodiments, the signal may be a digital signal, such as but not limited to: Non Return to Zero (NRZ), Return to Zero (RZ), Pulsed Amplitude Modulated (PAM), Quadrature Amplitude Modulated (QAM), Quadrature Phase Shift Keying or any other modulation scheme.

[0063] MCU 316 may comprise message generation module 317 and message retrieval module 318. Message generation module 317 may obtain the transmitter parameters, channel information, configuration, signal quality such as transmitted optical power, extinction ratio, optical modulation amplitude, eye diagram characteristics, transmitter serial number, manufacturer, set of default parameters, operation conditions including environmental parameters such as temperature, or the like, and generate a corresponding message.

[0064] The message generated by message generation module 317 may be applied o the transmitter management agent 332.

[0065] The message generated by message generation module 317 can be a digital or analog signal. In some examples the message may be in accordance with I2C, SPI, UART or any other communication protocol.

[0066] Transmitter management agent 332 is responsible for transmitting the message by converting the electrical management signal generated by the message generation module 317 to an optical signal on the same wavelength used for transmitting the actual data signals.

[0067] The embedded management signal may utilize the frequency range not used for the actual data as embedded by E / O converter, for example below 8 MHz, below 10 MHz, below 12 MHz, or the like. The management signal amplitude and / or phase may be selected in a way that does not affect the performance of the optical link, for example, does not harm the Bit Error Rate (BER) during the management data transmission.

[0068] After the exchange of management messages between the transmitting and receiving sides, and adjustment of the channel parameters on either or both sides, a significant improvement in the channel performance may be obtained, for instance, reduced BER.

[0069] The light may then be provided to the receiver side over optical fiber 128.

[0070] On the opposite direction, the light may be received from optical fiber 128, and may be provided to receiver management agent 340.

[0071] Receiver management agent 340 may retrieve the message comprising the information shared by the transmitter management agent, for example, the channel information as embedded into the light by transmitter management agent 332 of the transmitter switch.

[0072] The management data may be provided to message retrieval module 318 of MCU 316.

[0073] Message retrieval module 318 may retrieve the channel information received from the transmitter, which indicates the configuration and conditions of the transmitter side, and can then update the configuration of driver and CTLE 308 and / or TIA and equalizer (EQ) 312.

[0074] Moreover, in some examples, MCU 316 may generate an updated message to be embedded by transmitter management unit 332 when switch 300 is transmitting.

[0075] Thus, a loop is closed, and the transmitter may also utilize channel information received from the receiver side to update its configuration, parameters and behavior when transmitting information, such that the communication is optimized to the conditions on both ends of the communication.

[0076] This unique scheme enables the cooperation of the transmitter and receiver in updating their parameters and configuration for optimizing the quality of the transmission, thereby meeting requirements such as BER.

[0077] Moreover, by utilizing otherwise unused frequencies, the transmission intensity in the frequencies used for transmitting data is not harmed.

[0078] The received light is also provided to photodiode 336 which transforms it into a serial electric signal, which in turn is provided to electronic module 304 comprising TIA and EQ 312. The TIA may convert and amplify the photocurrent, from the low values detected by a photodiode to a voltage level which serializer / deserializer 112 can work with. The converted and amplified signal may then be provided to ASIC 108 for processing.

[0079] Referring now to Fig. 4, showing a block diagram of another embodiment of a switch and optical module, in accordance with some exemplary embodiments of the disclosure.

[0080] Switch 400 may be used, as above, as a transmitter and / or a receiver. In the shown embodiment, switch 400 is a transmitter and a receiver.

[0081] Switch 400 may comprise ASIC 108 which generates the data to be transmitted. ASIC 108 can comprise or be electrically coupled to serializer / deserializer 112 as in the figures above.

[0082] The serial signal may then be provided to driver 408. In some embodiments, driver 408 may match the signal voltage to a level which E / O converter 328 is adapted to operate with.

[0083] The signal may then be provided to E / O converter 328 for converting the actual data from the electrical to optical domain by modulating the light received from the light source 324.

[0084] The signal may then be provided to transmitter optical equalizer 416, for equalizing the transmitter in accordance with instructions received from message generation module 317 of MCU 316.

[0085] Implementation details of an optical equalizer may be found, for example, in US Patent App. No. 63 / 508,037 titled “Optical Equalization of Communication Networks”, filed on June 14, 2023 and assigned to the same assignee as the current application.

[0086] MCU 316 may comprise message generation module 317 and message retrieval module 318. Message generation module 317 may obtain the transmitter parameters and configuration, the signal quality, channel information, configuration, signal quality such as transmitted optical power, extinction ratio, optical modulation amplitude, transmitter serial number, manufacturer, set of default parameters, operation conditions, including environment, or the like, and generate a corresponding message.

[0087] MCU 316 may also generate instructions for updating the configuration of optical equalizer 416.

[0088] Transmitter management agent 332 is responsible for converting the electrical management signal generated by the message generation module to the optical signal on the same wavelength used for transmitting the actual data signals.

[0089] The embedded management signal may utilize the frequency range not used for the actual data as embedded by E / O converter, for example below 8 MHz, below 10 MHz, below 12 MHz, or the like. The management signal amplitude and / or phase may be selected in a way that does not affect the performance of the optical link, for example, does not harm the Bit Error Rate (BER) during the management data transmission. .

[0090] The light may then be provided to the receiver side through optical fiber 128.

[0091] On the opposite direction, the light may be received from optical fiber 128, and may be provided to receiver management agent 340.

[0092] Receiver management agent 340 may retrieve a message comprising the management data, also referred to as channel information, as embedded in the light by transmitter management agent 332 of the transmitter switch, for example in the frequencies below 10MHz.

[0093] The management data may be provided to message retrieval module 318 of MCU 316.

[0094] Message retrieval module 318 of MCU 316 may retrieve the data received from the transmitter, which indicates the conditions at the transmitter side, and can then update the configuration of driver 308 and / or TIA 312.

[0095] MCU 316 may further generate instructions for configuring receiver optical equalizer 420.

[0096] Moreover, in some examples, message generation module 317 of MCU 316 may generate an updated message to be embedded by transmitter management unit 332 when the switch is transmitting.

[0097] The received light is also provided to receiver optical equalizer 420 for equalization in accordance with the conditions of the transmitter and the receiver channels. The resulting signal may then be provided to photodiode 336 which transforms it into a serial electric signal, which in turn is provided to TIA 412. TIA 412 may amplify the voltage, from the low photocurrent values provided by a photodiode to a level whichserializer / deserializer 112 can work with. The amplified signal may then be provided to ASIC 108 for processing.

[0098] It is appreciated that optical module 404, including the light source 324, E / O converter 328, transmitter optical equalizer 416 and or / receiver optical equalizer 420, photodiode 336 transmitter management agent 332 and / or receiver management agent 340, may be monolithically integrated on the silicon photonic platform, or any other integrated photonics platform.

[0099] It is appreciated that although the disclosure is particularly suitable for data centers, it is in no way limited to such environments and may be equally applicable to any other environment.

[0100] The present invention may be a system, a method, and / or a computer program product. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present invention.

[0101] The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non- exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire.

[0102] Computer readable program instructions described herein can be downloaded to respective computing / processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and / or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and / or edge servers. A network adapter card or network interface in each computing / processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing / processing device.

[0103] Computer readable program instructions for carrying out operations of the present invention may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, such as "C", C#, C++, Java, Phyton, Smalltalk, or others. The computer readable program instructions may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field- programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present invention.

[0104] Aspects of the present invention are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations ofblocks in the flowchart illustrations and / or block diagrams, can be implemented by computer readable program instructions.

[0105] These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and / or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function / act specified in the flowchart and / or block diagram block or blocks.

[0106] The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0107] The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and / or flowchart illustration, and combinations of blocks in the block diagrams and / or flowchart illustration, can be implemented by special purpose hardware-based systemsthat perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions.

[0108] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0109] The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

CLAIMSWhat is claimed is:

1. A communication system comprising: a transmitter comprising: an Electrical-Optical (E / O) converter for converting light received from a light source, in accordance with an electric signal received from a driver, thereby generating data-carrying light to be transmitted through an optic fiber; a message generation module for generating a message indicating channel information associated with the transmitter; and a non-invasive management agent adapted to embed the message into the data-carrying light at frequencies lower than a predetermined threshold, thereby creating a management channel over the data-carrying light; and a receiver comprising: a non-invasive management agent adapted to retrieve a second message embedded within light transmitted by a second transmitter through the optic fiber, the second message indicating second channel information associated with the second transmitter; a message retrieval module for retrieving the second channel information associated with the second transmitter from the second message; and a photo diode for converting the light received through the optical fiber into an electric signal, wherein the second channel information is used for updating a configuration of at least one member of the transmitter, and wherein the transmitter and the receiver are parts of a communication system within a data center.

2. The communication system of Claim 1, wherein the transmitter and the receiver are implemented as a single device.

3. The communication system of Claim 2, wherein the message generation module and the message retrieval module are comprised in a single Micro Controller Unit (MCU).

4. The communication system of Claim 1, wherein the transmitter further comprises an Equalizer adapted to mitigate channel impairments, wherein the first MCU sends instructions to the equalizer how to modify parameters of the transmitter in accordance with the channel information associated with the transmitter, and wherein the second MCU sends instructions to the equalizer how to modify parameters of the transmitter in accordance with the channel information associated with the second transmitter.

5. The communication system of Claim 4, wherein the equalizer is a Continuous -Time Linear Equalizer (CTLE).

6. The communication system of Claim 4, wherein the equalizer is an optical equalizer.

7. The communication system of Claim 1, wherein the receiver further comprises a transimpedance amplifier (TIA) with equalizer adapted to mitigate channel impairments, wherein the first MCU sends instructions to the TIA and equalizer how to modify parameters of the receiver in accordance with the channel information associated with the transmitter, and wherein the second MCU sends instructions to the TIA and equalizer how to modify parameters of the receiver in accordance with the channel information associated with the second transmitter.

8. The communication system of Claim 1, wherein the receiver further comprises an equalizer; andwherein the second MCU sends instructions to the equalizer how to modify parameters of the communication system in accordance with the channel information associated with the second transmitter.

9. The communication system of Claim 1, wherein the transmitter further comprises an optical equalizer, and wherein the optical equalizer is configured in accordance with instructions received from the first MCU and from the second MCU.

10. The communication system of Claim 1, wherein the receiver comprises an optical equalizer, and wherein the optical equalizer is configured in accordance with instructions received from the first MCU and from the second MCU.

11. The communication system of Claim 1, wherein the transmitter is provided by a first manufacturer and the receiver transmitter is provided by a second manufacturer, different from the first manufacturer.

12. The communication system of Claim 1, wherein the predetermined threshold is at most 12MHz.

13. The communication system of Claim 1, wherein the transmitter further comprises a driver for attenuating the electric signal to a level compatible with the E / O converter, and wherein the receiver further comprises a transimpedance amplifier (TIA) for amplifying the electric signal.

14. A method for operating a communication system within a data center, the method comprising: converting by an E / O converter light received from a light source, in accordance with an electric signal received from a driver, thereby generating data-carrying light to be transmitted through an optic fiber; generating a message indicating channel information associated with a transmitter switch; and embedding the message into the data-carrying light at frequencies lower than a predetermined threshold, thereby creating a management channel over the data-carrying light.

15. The method of Claim 14, further comprising:retrieving by a receiver the message embedded within the data- carrying light; retrieving the second channel information associated with the transmitter from the message; and updating a configuration of at least one member of the receiver switch in accordance with the channel information associated with the transmitter.

16. The method of Claim 14, further comprising updating a configuration of at least one member of the transmitter switch in accordance with the channel information associated with the transmitter.

17. The method of Claim 14, further comprising equalizing the communication channel in accordance with channel information associated with the transmitter or the receiver.

18. The method of Claim 14, wherein the transmitter is provided by a first manufacturer and the receiver transmitter is provided by a second manufacturer, different from the first manufacturer.

19. The method of Claim 14, wherein the predetermined threshold is at most 12MHz.

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