HK1159887B - Ethernet communication system, multi-rate ethernet device and method thereof - Google Patents

Description

Ethernet communication system, multi-rate Ethernet device and method thereof

Technical Field

The invention relates to an Ethernet system and method. More particularly, the present invention relates to a method and system for use in frequency division multiplexing high speed physical layer devices.

Background

As the standardized transmission rates increase by orders of magnitude, the capabilities of ethernet devices are also increasing. In a relatively short time, the transmission rate of standardized Ethernet devices has increased from 10Mbit/s to 100Mbit/s, from 100Mbit/s to 1Gbit/s, and even more recently from 1Gbit/s to 10 Gbit/s. Efforts are currently underway to determine the next transmission rate that will be the next standard for ethernet performance. The next transmission rate, whether 40Gbit/s or 100Gbit/s, will be much higher than 10 Gbit/s.

The large increase in standardized transmission rates provides a tremendous convenience for the increase in available bandwidth in ethernet networks. The large increase in available bandwidth has led to significant changes in applications that can be supported by various types of networks. The performance barriers that prevent some application types are also reduced due to the reduced bandwidth consumption.

Although the tremendous increase in transmission rates has realized tremendous interest, it may also create other cost barriers that hinder the development of some applications. Implementation costs, such as system complexity, improvements in physical equipment (e.g., cabling), increased energy consumption, etc., will offset the benefits of increased transmission rates. Therefore, a solution is needed to achieve an increase in transmission rate with a low cost implementation.

Disclosure of Invention

A system and/or method for a frequency division multiplexing high speed physical layer device, substantially as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims.

According to an aspect of the present invention, there is provided an ethernet communication system including:

a first baseband Ethernet transmitter having a determined signal mechanism and generating a first output located in a first frequency spectrum;

a second baseband Ethernet transmitter having the determined signal mechanism and generating a second output;

a mixer for transferring (shift) the second output of the second baseband Ethernet transmitter to a second frequency spectrum different from the first frequency spectrum; and

a combiner to combine at least a portion of the first output located in the first frequency spectrum with at least a portion of the shifted second output located in the second frequency spectrum for transmission on a single line pair.

Preferably, the first baseband ethernet transmitter is a 10GBASE-T transmitter.

Preferably, the first baseband ethernet transmitter is assigned to a first port and the second baseband ethernet transmitter is assigned to a second port, the second port being independently addressable with respect to the first port.

Preferably, the first and second baseband ethernet transmitters are assigned to the same port.

Preferably, the first and second baseband ethernet transmitters are 10GBASE-T transmitters and the first and second baseband ethernet transmitters are assigned to the same 40G port.

Preferably, one of the first and second baseband ethernet transmitters has a low power state in addition to the active state, the low power state being entered to save power while the other of the first and second baseband ethernet transmitters remains in the active state.

Preferably, the first and second baseband ethernet transmitters are integrated with the controller.

According to another aspect of the present invention, there is provided a multi-rate ethernet device comprising:

a plurality of baseband Ethernet transmitters, each of the plurality of baseband Ethernet transmitters using a same determined signal mechanism and generating a plurality of corresponding outputs;

a plurality of mixers to generate a plurality of frequency shifted outputs, each of the plurality of frequency shifted outputs having a different frequency spectrum, respectively; and

a combiner to combine at least a portion of each of the plurality of frequency shifted outputs for transmission on a single line pair,

wherein the multi-rate Ethernet device has a first mode of operation in which all of the plurality of baseband Ethernet transmitters are active and a second mode of operation in which only a portion of the plurality of baseband Ethernet transmitters are active.

Preferably, each of the plurality of baseband ethernet transmitters is a 10GBASE-T transmitter, and the first mode of operation is capable of transmitting at 40G and the second mode of operation is capable of transmitting at 10G.

Preferably, one of said first mode of operation and said second mode of operation is selected upon activation of said multi-rate ethernet device.

Preferably, one of the first and second operating modes is selected according to the type of cable containing the single wire pair.

Preferably, the multi-rate ethernet device is capable of switching between the first mode of operation and the second mode of operation while operating so as to conserve power.

Preferably, the plurality of baseband ethernet transmitters are integrated with the controller.

According to another aspect of the present invention, there is provided a method in a transmitting-end communication device, including:

transmitting an output of a first baseband ethernet transmitter in a first frequency spectrum of the line-pair;

transmitting an output of a second baseband Ethernet transmitter in a second frequency spectrum of the line-pair;

determining whether a usage rate of a link containing the pair is below a threshold; and

transitioning the second baseband Ethernet transmitter from an active state to a low power state when the determining indicates that the usage of the link is below the threshold, the transitioning process at least temporarily reducing the second baseband Ethernet transmitter's usage of the second spectrum.

Preferably, the transmitting comprises transmitting at a 10G rate.

Preferably, said transmission by said first and second baseband ethernet transmitters uses the same signal mechanism.

Drawings

In order to describe the manner in which the above-recited and other advantages and features of the invention can be obtained, a detailed description of the above briefly described invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

fig. 1 is a schematic diagram of an OSI layer;

FIG. 2 is a schematic diagram of an exemplary Ethernet physical layer device;

FIG. 3 is a schematic diagram of an exemplary embodiment of frequency division multiplexing in an Ethernet physical layer device;

FIG. 4 is a schematic diagram of a typical frequency spectrum used by a frequency division multiplexed Ethernet physical layer device;

FIG. 5 is a process flow diagram of the present invention.

Detailed Description

Various embodiments of the invention are discussed in detail below. It should be understood that while specific embodiments have been discussed, this is for illustrative purposes only. It will be appreciated by those skilled in the art that other components and configurations may be used without departing from the spirit and scope of the invention.

Ethernet has become an increasingly popular technology for use in a variety of environments, including twisted pair, backplane, and fiber optic applications. The simple nature inherent in ethernet makes this technology applicable to a variety of media, a variety of rates, and a variety of distances. These features make ethernet a viable technology option across high-speed laboratory networks, business networks, and even customer networks.

With the popularization of ethernet, the scale benefit of ethernet is more and more attractive. Thus, obtaining a simple, low-cost ethernet solution is an important factor in facilitating continued expanded use thereof.

Note that ethernet transmission rates have evolved dramatically, and the transmission rates that can be used in the new generation of ethernet devices have increased by orders of magnitude. However, significant increases in transmission rates bring some implementation costs, and thus increases in system complexity, physical device improvement (e.g., cable) costs, power consumption, and the like offset the benefits of increased transmission rates. These implementation costs represent a challenge to practical design when considering next generation ethernet devices (e.g., 40Gbit/s or 100 Gbit/s).

There is currently no 40Gbit/s or 100Gbit/s ethernet device identified for twisted pair applications. However, the pace of technology development has determined that ethernet devices will come out. Since the increase in bandwidth from 10Gbit/s to 40Gbit/s or 100Gbit/s is enormous, the increase in implementation cost of this improved solution is also enormous. This implementation cost dictates that low rates must be used due to the time required to develop a low cost interface based on this technology.

According to the invention a cost-effective solution is provided to enable next generation transmission (i.e. transmission rates higher than 10 Gbit/s) over structured cabling. To illustrate the features of the present invention, reference is first made to fig. 1, which shows the ISO Open System Interconnection (OSI) reference model and its correspondence to the IEEE802.3 layering.

As shown, the PHY includes a Physical Coding Sublayer (PCS), a Physical Media attachment sublayer (PMA), a Physical Media Dependency (PMD), and AN auto-negotiation (AN). The PHY is connected to the twisted pair via a Media Dependent Interface (MDI).

As shown, the physical layer (often referred to as PHY) includes a Physical Coding Sublayer (PCS), a Physical Medium Attachment (PMA), a physical medium association layer (PMD), and AN auto-negotiation (AN). As shown, the PCS is connected to a coordination sublayer (RS) that provides signal mapping between the interface 110 and the MAC layer. In various examples, interface 110 may be based on a connection unit interface (AUI), a Media Independent Interface (MII), a Serial MII (SMII), a Reduced MII (RMII), a Gigabit MII (GMII), a Reduced GMII (RGMII), a Serial GMII (SGMII), a four serial gigabit MII (QSGMII), a 10 gigabit MII (XGMII), an SXMIII, an XFI, a 10-Gbps AUI (XAUI), a 40 Gigabit MII (GMXLII), a 40-Gbps AUI (XLAUI), a 100 gigabit MII (CGMIII), a 10Gbps AUI (CAUI), and so forth. In various embodiments, one or more portions of the PHY may be internal or external to the MAC. In one embodiment, an expander (extender), such as the XAUI extension sublayer (XGXS) or XFI, may be used between the MAC/PHY. Similar extenders, such as XLAUI and CAUI, may also be determined for higher transmission rates.

Generally, PMA extracts PCS from the physical medium. Therefore, the PCS may not know the media type. The main functions of the PMA include transmitting and receiving code sets between the corresponding PCS and PMA, and serializing (serializing)/deserializing (deserializing) code sets for transmission/reception on the underlying PMD, clock recovery from encoded data (e.g., 4B/5B, 8B/10B, 64B/65B, 64B/66B, etc.) provided by the PMD, and transmit and receive bits (bits) between the corresponding PMA and PMD.

PMD is typically used to generate electrical or optical signals depending on the nature of the physical medium to which it is connected. The PMD signal is sent to a Media Dependent Interface (MDI), which is the actual connection medium (including connectors) for the various media supported.

Generally, the AN provides linked devices with the functionality to detect capabilities (modes of operation) supported by devices at the other end of the link, determine commonly used capabilities, and configure joint operation. Typically, the AN process determines the best mode of operation (or most common standard) shared by the two PHY devices. Here, a particular priority between different modes of operation may be determined, e.g., high speed over low speed, full duplex over half duplex at the same rate. AN may also apply to links unequally.

In one embodiment, the AN may be designed to support multiple modes. For example, AN can be designed to support not only the standard 10Mbit/s, 100Mbit/s, 1Gbit/s, and 10Gbit/s modes of operation, but also the 40Gbit/sPHY mode of operation over structured cabling. In another embodiment, the AN may be designed to select from a complex set of operating modes that include not only the standard operating modes described above, but also non-standard operating modes (e.g., 2.5Gbit/s, 5Gbit/s, etc. transmission over structured cable). In yet another embodiment, the AN may be used to auto-negotiate to different rates. Here, each PHY may test a channel and exchange information about the channel (e.g., cable type, cable length, etc.), which may be used to select a particular mode of operation. In various examples, the AN process may select a 40Gbit/s transmission rate when a category 7A cable is detected, a 10Gbit/s transmission rate when a category 6A cable is detected, a 40Gbit/s transmission rate when a 15 meter long category 6A cable is detected, and so on. In general, the AN process may be designed to select the mode of operation based not only on the PHY's own functionality, but also on the particular communication channel therebetween.

Due to the wide variety of cables that can be provided, there are also a wide variety of operating modes. With the development of ethernet PHY technology, cable technology has also been developed. To facilitate higher transmission rates, more stringent limits on the quality of the cables, connectors and magnetics will determine replacement of existing installations.

Various types of ethernet compatible cables exist. For example, the performance characteristics represented by the category 3 unshielded twisted pair cable can achieve 10BASE-T transmission but not 100BASE-TX transmission, which requires the performance characteristics represented by the category 5 or category 5e cable for 100BASE _ TE transmission. Category 6 cables were later defined as a cable standard that supports 1000BASE-T operation. Since then, cable development has led to the creation of improved category 6A, 7A cables capable of supporting frequencies up to 1Ghz and enhanced 7A or newer cables capable of supporting frequencies up to 2Ghz and higher.

The transmission rate on a twisted pair link is related to the channel condition, which in turn is related to the cable type, cable length, connector, etc. As mentioned above, newer enhanced 7A cables have bandwidths as high as 2Ghz, such large bandwidths are considered sufficient to support 40GBASE-T transmission.

It is a feature of the present invention that implementation costs and other development costs incurred in the development of next generation components can be reduced by facilitating a solution to reuse existing ethernet device structures.

For example, referring to FIG. 2, FIG. 2 illustrates an existing Ethernet device architecture for 10GBASE-T operation. As shown, the PHY transceiver includes a MAC I/F210, the MAC I/F210 designed to support, for example, an XGMII or XAUI interface. At the transmit end, the PHY transceiver may include a PCS encoding 221, a scrambler 222, a Low Density Parity Check (LDPC) 223, a double-side-of-128 (DSQ) mapper 224, a precoder 225, a digital-to-analog converter (DAC) 226, and a mixer (Hybrid) 240. Accordingly, at the receiving end, the signal received by the mixer 240 is processed by the Variable Gain Amplifier (VGA) 237, analog-to-digital converter (ADC) 236, crosstalk (Xtalk) canceller and equalizer 235, 128DSQ Soft Decisions (Soft Decisions) 234, LDPC decode 233, descrambler 232, and PCS decode 231 transmits the signal to the MAC I/F210.

In the present invention, it is desirable to multiplex existing PHY transceivers (e.g., as shown in fig. 2) in next generation devices. This structural multiplexing can provide a simple method in which the transmission capacity can be increased without entailing a large cost increase caused by switching to a newly designed structure supporting the next generation transmission rate.

Figure 3 illustrates one exemplary embodiment utilizing existing structures. As shown, the demultiplexer 310 receives one Transmit (TX) data stream and outputs 4 demultiplexed data streams to baseband transmitters 322, 324, 326, 328. In one example, the received TX data stream is a 40Gbit/s data stream and the 4 demultiplexed data streams are each 10Gbit/s data streams. It should be noted that the principles of the present invention are not related to a particular combination of data transmission rates. For example, different proportions of demultiplexing may be used to match a given set of baseband transmitters.

Using the example of a 40Gbit/s data stream, demultiplexer 310 is designed to produce 4 10Gbit/s demultiplexed data streams. Each 10Gbit/s demultiplexed data stream may be processed by a baseband transmitter 322, 324, 326, 328 implementing an existing 10G architecture (such as that shown in fig. 2). In practice, each baseband transmitter 322, 324, 326, 328 may implement the existing 10GBASE-T signaling mechanism, respectively.

The outputs of the baseband transmitters 322, 324, 326, 328 are passed to corresponding mixers (mixers) 332, 334, 336, 338. The mixers 332, 334, 336, 338 are designed to implement a frequency division multiplexing scheme in which at least the outputs of the baseband transmitters 324, 326, 328 are frequency shifted to different portions of the spectrum of the twisted pair communication channels.

Fig. 4 shows an example of a frequency spectrum of a 40Gbit/s data stream transmitted over an enhanced 7A cable using frequency division multiplexing. As described above, the enhanced 7A cable has a bandwidth of about 2 Ghz. Each 10GBASE-T baseband transmitter would require near 400Mhz bandwidth. In the illustrated example, the 2Ghz spectrum may be divided into 4 500Mhz bands 1-4, where each 500Mhz band is designed to carry the output of one baseband transmitter. For the available ranges 0-400Mhz, 500-900Mhz, 1000-1400Mhz and 1500-1900Mhz, the frequency shifted outputs of the baseband transmitter contain about 100Mhz space between them. It is noted that the available spectrum is related to the selected cables, which are chosen to favor a given number and combination of baseband transmitters whose joint mode of operation will yield the desired throughput.

As shown in fig. 3, the receiving end includes mixers 342, 344, 346, 348 for capturing baseband signals from different frequency bands. The outputs of the mixers 342, 344, 346, 348 are then provided to corresponding baseband receivers 352, 354, 356, 358. Figure 2 shows a prior art architecture of a 10GBASE-T receiver that can be used by the baseband receivers 352, 354, 356, 358. The outputs of the baseband receivers 352, 354, 356, 358 are provided to a multiplexer 360, and the multiplexer 360 generates a received 40Gbit/s data stream.

As described above, frequency division multiplexing of twisted pair channels facilitates structural multiplexing. This structural reuse enables efficient scaling mechanisms (scaling mechanisms) that reduce the large implementation cost of next generation ethernet devices. Of course, one advantage of the extension mechanism is that it can efficiently convert to an intermediate rate rather than the next highest standard rate. For example, by using two 10Gbit/s baseband transmitter and receiver sets, a 20Gbit/s link rate can be supported over a cable plant with a 1Ghz bandwidth. Thus a low cost stepwise transition (migration) approach is achieved.

It is noted that in one embodiment, a frequency division multiplexing scheme can be used without the demultiplexer 310 and the multiplexer 360. In this embodiment, the baseband transmitters 322, 324, 326, 328 may be used as part of an integrated 4-PHY chip supporting 4 independent 10Gbit/s channels and include controllers, switches, buffers, connectors, and the like. Here, the frequency division multiplexing mechanism draws 4 independent virtual lines from one line, effectively increasing the capacity of the cable by a factor of 4.

In another embodiment using demultiplexer 310 and multiplexer 360, 40Gbit/sPHY may support multiple modes. Here, for 40Gbit/s mode, all 4 baseband transmitters 322, 324, 326, 328 may be used, while for 10Gbit/s mode only one baseband transmitter (e.g., 322) may be used. If the one baseband transmitter also supports legacy modes (standard and/or non-standard), the ethernet device may also support other modes (e.g., 5Gbit/s, 2.5Gbit/s, 1Gbit/s, 100Mbit/s, 10Mbit/s modes). The AN may enable selection of various operating modes that support operating modes selected from frequency division multiplexed 40Gbit/s operating modes, non-multiplexed 10Gbit/s operating modes, and existing standard/non-standard operating modes.

Fig. 5 illustrates an Energy Efficient Ethernet (EEE) application in which multiple modes of frequency division multiplexing equipment may be used. As noted above, energy cost is a primary consideration in any implementation, as are those supporting higher transmission rates. As the trend of continued escalation of energy costs has increased in recent years, energy efficiency has become a primary consideration in ethernet devices.

As shown in fig. 5, the EEE process begins at step 502, where the frequency division multiplexed ethernet device is configured to be operational. For example, at start-up, the frequency division multiplexed ethernet device may be configured to operate in a 40G mode using 4 10G baseband transmitters. After the frequency division multiplexed ethernet device is configured in the 40G mode of operation, the process continues to step 504, where link usage is monitored.

Generally, an EEE control strategy for determining when to enter a power saving state, which power saving state to enter (i.e., power saving level), how long to stay in the power saving state, which power saving state to transition from a previous power saving state, etc., may monitor link usage. The EEE control policy entity may comprise software code capable of interoperating with one or more layers, including the PHY, MAC, switch layer, or some portion of other sub-layers in the host. In one embodiment, the EEE control policy is in the PHY. The EEE control policy entity may analyze traffic on the physical link as well as analyze the operation and/or processing of data within itself or within a link partner. In this manner, the EEE control policy entity may exchange information from or about one or more layers of the OSI hierarchy in order to establish and/or implement an EEE control policy. The software-based EEE control strategy can be designed to base ITs resolution on a combination of IT managers, default (default) software configurations, the nature of the traffic bandwidth of the link itself, the time of day, or static settings established by other fixed sets of parameters. For example, the EEE control strategy may be designed to detect idle or non-idle conditions of ports, queues, buffers, etc. to determine whether to transition to or from a power saving state.

At step 506, when link usage is monitored, a determination is made as to whether the monitored link usage suggests a need for a state transition. If it is determined that a state transition is not required, the process continues with monitoring link usage. However, if it is determined that the state transition is required, the process returns to step 502, and in step 502, the operation state of the frequency division multiplexing ethernet device is configured. Here, the frequency division multiplexed ethernet device may be configured to transition from the previous active 40G state to the low power state. In one embodiment, a low power state of a frequency division multiplexed ethernet device may be configured by reducing power consumption of at least one 10G baseband transmitter channel. The reduced power consumption may be represented by a reduction in the transmission rate of the at least one 10G baseband transmitter channel. In various examples, one of the higher frequency shifted outputs (e.g., produced by baseband transmitters 324, 326, 328) may be turned off to produce a 30G throughput, or one of the baseband transmitters may be turned off to produce a 25G throughput when the second baseband transmitter selects the 5G mode of operation, or only one of the baseband transmitters may be turned on to produce a throughput for the only active baseband transmitter selected mode of operation (e.g., 10G, 5G, 2.5G, 1G, 100M, 10M). The frequency division multiplexed ethernet device may continue to stay in the selected low power mode of operation until link usage suggests a need to return to an active 40G state of operation.

As described above, a frequency division multiplexed ethernet device may support multiple operating modes at startup or active operation, which may support different configurations. The structural multiplexing that enables efficient expansion can enable the complexity of the run mode.

It should be noted that the 40G/10G example described above is not intended to limit the scalability provided by the fabric multiplexing. For example, M × G ethernet devices for frequency division multiplexing can be manufactured using M1G baseband transmitters.

It is also noted that the principles of the present invention are not to be construed as being limited to the 10G example shown in fig. 2. More generally, the principles of the present invention may be applied to any existing architecture, including 10Mbit/s, 100Mbit/s, 1Gbit/s, 10Gbit/s (e.g., 10GBASE-KR, KX4, CR 1), 40Gbit/s (e.g., 40GBASE-CR 4), 100Gbit/s (e.g., 100GBASE-CR 10), and the like. In this regard, the principles of the present invention may also be applied to systems with various standard, non-standard (e.g., 2.5Gbit/s, 5Gbit/s, 20Gbit/s, 25Gbit/s, 28Gbit/s, etc.) or future (e.g., 40Gbit/s, 100Gbit/s, 250Gbit/s, 400Gbit/s, 1000Gbit/s, etc.) link rates. The principles of the present invention may also be applied to shared media links (e.g., Passive Optical Networks (PONs)) and point-to-point (P2P) fiber networks.

In one embodiment, the variable speed frequency division multiplexed ethernet device may be generated based on channel properties (e.g., cable type, cable length, bundling limitations, etc.) discovered by the channel diagnostics. This information can then be used to select a particular number and combination of baseband transmitter/receivers (and need not be the same) in order to obtain the desired bandwidth for a particular channel. In general, a particular device implementation is related to the baseband transmitter/receiver used, the amount of available cable bandwidth, the efficiency of the use of the available cable bandwidth (e.g., carrier space), and so on. It is noted that the principles of the present invention may also be applied unequally to links.

Various aspects of the invention will become apparent to those skilled in the art from the above detailed description. While certain features of the invention have been described above, the invention is capable of other embodiments and of being practiced and carried out in various ways that will be apparent to those skilled in the art upon reading the disclosure of the disclosure and, thus, are not intended to be exhaustive of such other embodiments. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

Claims (10)

1. An ethernet communication system, comprising:

a first baseband Ethernet transmitter having a determined signal mechanism and generating a first output located in a first frequency spectrum;

a second baseband Ethernet transmitter having the determined signal mechanism and generating a second output;

a mixer to transfer the second output of the second baseband Ethernet transmitter to a second frequency spectrum different from the first frequency spectrum;

a combiner to combine at least a portion of the first output located in the first frequency spectrum with at least a portion of the transferred second output located in the second frequency spectrum for transmission on a single line pair; and

a link usage monitor that:

monitoring usage of a corresponding communication link on the single line pair,

determining whether a transition of an operation state of at least one of the first baseband Ethernet transmitter and the second baseband Ethernet transmitter is required based on the usage amount of the link, and

configuring the at least one baseband Ethernet transmitter by both a transmission rate and an active state of the at least one baseband Ethernet transmitter to adapt an overall throughput capability of the at least one baseband Ethernet transmitter to the link usage.

2. The system of claim 1, wherein the first baseband ethernet transmitter is a 10GBASE-T transmitter.

3. The system of claim 1, wherein the first baseband ethernet transmitter is assigned to a first port and the second baseband ethernet transmitter is assigned to a second port, the second port being independently addressable relative to the first port.

4. The system of claim 1, wherein one of the first and second baseband ethernet transmitters has a low power state in addition to the active state, the low power state being entered to conserve power while the other of the first and second baseband ethernet transmitters remains in the active state.

5. A multi-rate ethernet device, comprising:

a plurality of baseband Ethernet transmitters, each of the plurality of baseband Ethernet transmitters using a same determined signal mechanism and generating a plurality of corresponding outputs;

a plurality of mixers to generate a plurality of frequency shifted outputs, each of the plurality of frequency shifted outputs having a different frequency spectrum, respectively; and

a combiner to combine at least a portion of each of the plurality of frequency shifted outputs for transmission on a single line pair,

wherein the multi-rate Ethernet device has a first mode of operation in which all of the plurality of baseband Ethernet transmitters are active and a second mode of operation in which only a portion of the plurality of baseband Ethernet transmitters are active;

and the multi-rate ethernet device further comprises a link usage monitor that:

monitoring usage of a corresponding communication link on the single line pair,

determining whether a transition of an operational state of at least one of the plurality of baseband Ethernet transmitters is required based on the amount of usage of the link, and

configuring the at least one baseband Ethernet transmitter by both a transmission rate and an active state of the at least one baseband Ethernet transmitter to adapt an overall throughput capability of the at least one baseband Ethernet transmitter to the link usage.

6. The device of claim 5, wherein each of the plurality of baseband ethernet transmitters is a 10GBASE-T transmitter, and wherein the first mode of operation is capable of transmitting at 40G and the second mode of operation is capable of transmitting at 10G.

7. The device of claim 5, wherein one of the first mode of operation and the second mode of operation is selected upon booting the multi-rate Ethernet device.

8. The apparatus of claim 7, wherein one of the first mode of operation and the second mode of operation is selected based on a type of cable containing the single wire pair.

9. The device of claim 5, wherein the multi-rate Ethernet device is capable of switching between the first mode of operation and the second mode of operation while operating so as to conserve power.

10. A method in a transmitting-end communication device, comprising:

transmitting an output of a first baseband ethernet transmitter in a first frequency spectrum of the line-pair;

transmitting an output of a second baseband Ethernet transmitter in a second frequency spectrum of the line-pair;

determining whether a usage rate of a link containing the pair is below a threshold;

transitioning the second baseband Ethernet transmitter from an active state to a low power state when the determining indicates that the usage of the link is below the threshold, the transitioning process at least temporarily reducing the second baseband Ethernet transmitter's usage of the second spectrum; and

the at least one baseband ethernet transmitter is further configured by its transmission rate to adapt its overall throughput capability to the link usage.