EP2396923A2

EP2396923A2 - Power consumption management for multicarrier arrangement

Info

Publication number: EP2396923A2
Application number: EP10708897A
Authority: EP
Inventors: Joon Bae Kim; Marcos Tzannes
Original assignee: Lantiq Deutschland GmbH
Current assignee: Intel Germany Holding GmbH
Priority date: 2009-02-09
Filing date: 2010-02-08
Publication date: 2011-12-21
Also published as: WO2010089145A2; WO2010089145A3; CN102308517A

Abstract

At least one implementation relates to a multicarrier apparatus that generates one or more parameters that define an activity period. The activity period may span one or more communication cycles, or one or more fractions of a communication cycle. The multicarrier apparatus may be in a low-power mode during the activity period. The one or more parameters may be communicated to a controller apparatus. The controller apparatus may instruct other multicarrier apparatuses that the multicarrier apparatus is unavailable during the inactive period.

Description

POWER CONSUMPTION MANAGEMENT FOR MULTICARRIER

ARRANGEMENTS

BACKGROUND

[0001] Packet-based communication technologies, such as ITU G.hn, HomePNA, HomePlug® AV and Multimedia over Coax Alliance (MoCA), are becoming increasingly important due to the significant advances in broadband networks capable of delivering multimedia-rich IP-based services. As the demand for such services increases, service providers are looking for improved ways to distribute digital content within consumers' homes. The aforementioned technologies are designed specifically for this purpose.

[0002] Digital subscriber line (DSL) technology may be used to transform an ordinary telephone line (e.g., copper wire twisted-pair) into a broadband communication link. DSL technology achieves this by sending signals over the telephone line in previously unused high frequencies.

[0003] Over the years, DSL technology has evolved into a family of specific, standardized implementations. These various implementations, which include among others Asymmetric Digital Subscriber Line (ADSL), ADSL2, ADSL2+, Very high speed DSL (VDSL), VDSL2, G.Lite, and High bit rate Digital Subscriber Line (HDSL), offer a variety of transmission speeds and transmission distances. It is common to refer to the various DSL implementations that have evolved over the years collectively as xDSL.

[0004] Wireless communication technology may be used in connection with DSL technology to increase the general mobility of devices that are used to access a broadband communication link. A common wireless communication technology used in connection with DSL technology and other broadband services includes the various IEEE 802.11 standards for wireless LANs.

[0005] Various xDSL implementations typically employ either Carrier-less Amplitude and Phase (CAP) modulation or discrete multi-tone (DMT) modulation. CAP modulation is a variation of quadrature amplitude modulation (QAM). CAP modulation produces the same form of signal as QAM without requiring in-phase and quadrature carrier components. DMT modulation is a modulation method in which the available bandwidth of a communication channel is divided into numerous orthogonal sub-channels. Sub-channel is also referred to as sub-carrier or tone. Each tone of a DMT communication system is capable of acting as a communications sub-channel that carries information between a transmitter and a receiver. Multicarrier systems that make use of DMT modulation may also be referred to as systems that employ Orthogonal Frequency Division Multiplexing (OFDM). OFDM is also the modulation method employed by many wireless communication technologies, including ITU G.hn, HomePlug® AV, MoCA, IEEE 802.11 and IEEE 802.16 (WiMAX). Technologies implementing DMT, OFDM and other multicarrier modulation schemes are generalized herein as being multicarrier systems.

[0006] Multicarrier systems enable high data rates to be achieved over wireless and wireline networks, as data may be separated and simultaneously sent over separate sub-channels operating at different frequencies. While simultaneously transmitting over multiple sub-channels greatly improves data throughput, the modulation technique may increase the power consumption of the transmitter and receiver. Efficiently managing power consumption of communication devices has become increasingly important as the devices become smaller and efficiencies of such devices become vital.

[0007] The independent claims define the invention in various aspects. The dependent claims define embodiments of the invention.

[0008] In a first aspect, the invention encompasses a method, comprising: determining an activity period to be associated with a multicarrier apparatus; generating a message that includes at least one parameter that identifies at least a portion of the activity period; and transmitting the message. At least one effect of the foregoing method is that the multicarrier apparatus may enter a power saving mode during the activity period.

[0009] In an embodiment of the method according to the invention in the first aspect, the at least one parameter that identifies the at least a portion of the activity period is a cycle identifier, the cycle identifier specifying an initial cycle in which the multicarrier apparatus will enter a first mode. In an embodiment, the generated message further includes another parameter that identifies a number of one or more cycles in which the multicarrier apparatus will be in the first mode. In an embodiment, the generated message further includes yet another parameter that identifies a number of zero, one, or more cycles in which the multicarrier apparatus will be in a second mode, the number of zero, one, or more cycles in which the multicarrier apparatus will be in the second mode to occur after the number of one or more cycles in which the multicarrier apparatus will be in the first mode. At least one effect of the foregoing method is that the multicarrier apparatus may enter a power saving mode during the activity period. A further effect is that the parameter(s) enables efficient identification of at least a portion of the activity period. [0010] In an embodiment of the method according to the invention in the first aspect, the at least one parameter that identifies the at least a portion of the activity period is a time instance identifier, the time instance identifier specifying a point in time within a cycle in which the multicarrier apparatus will enter a first mode. At least one effect of the foregoing method is that the multicarrier apparatus may enter a power saving mode during the activity period. A further effect is that the time instance identifier enables granular identification of at least a portion of the activity period.

[0011] In an embodiment of the method according to the invention in the first aspect, the at least one parameter that identifies the at least a portion of the activity period is a number of one or more cycles in which the multicarrier apparatus is to be in a first mode. At least one effect of the foregoing method is that the multicarrier apparatus may enter a power saving mode during the activity period. A further effect is that identifying a number of one or more cycles enables efficient identification of at least a portion of the activity period.

[0012] In an embodiment of the method according to the invention in the first aspect, the activity period is a period in which the multicarrier apparatus is in a low-power mode.

[0013] In an embodiment of the method according to the invention in the first aspect, the activity period is a period in which the multicarrier apparatus is in a full-power mode.

[0014] In an embodiment of the method according to the invention in the first aspect, the activity period is an active period in which the multicarrier apparatus is at least capable of receiving data transmitted from another multicarrier apparatus. [0015] In an embodiment of the method according to the invention in the first aspect, the activity period is an inactive period in which the multicarrier apparatus is at least unable to receive data transmitted from another multicarrier apparatus.

[0016] In an embodiment of the method according to the invention in the first aspect, the method further comprises: receiving a broadcast message confirming the activity period has been acknowledged; and entering a predefined power mode for the activity period. At least one effect of the foregoing method is that the multicarrier apparatus is able to confirm by way of the broadcast message that it may enter the activity period knowing that other multicarrier apparatuses are aware that it will be in the activity period.

[0017] In an embodiment of the method according to the invention in the first aspect, the at least one parameter that identifies the at least a portion of the activity period is a time slot identifier associated with a cycle, the time slot identifier specifying an initial time slot in which the multicarrier apparatus will enter a first mode. At least one effect of the foregoing method is that the multicarrier apparatus may enter a power saving mode during the activity period. A further effect is that the time slot identifier enables granular identification of at least a portion of the activity period.

[0018] In an embodiment of the method according to the invention in the first aspect, the at least one parameter that identifies the at least a portion of the activity period is a time slot identifier associated with a cycle, the time slot identifier specifying an initial time slot in which the multicarrier apparatus will enter a first mode. In an embodiment, the generated message further includes another parameter that identifies a number of one or more time slots in which the multicarrier apparatus will be in the first mode. In an embodiment, the generated message further includes yet another parameter that identifies a number of zero, one, or more time slots in which the multicarrier apparatus will be in a second mode, the number of zero, one, or more time slots in which the multicarrier apparatus will be in the second mode to occur after the number of one or more time slots in which the multicarrier apparatus will be in the first mode.

[0019] In an embodiment of the method according to the invention in the first aspect, the activity period is a combination of one or more active periods in which the multicarrier apparatus is at least capable of receiving data transmitted from another multicarrier apparatus and one or more inactive periods in which the multicarrier apparatus is at least unable to receive data transmitted from another multicarrier apparatus. At least one effect of the foregoing method is that the multicarrier apparatus may enter a power saving mode during inactive periods and operate at full-power during active periods. A further effect is that consecutive active and inactive periods may be defined.

[0020] In a second aspect the invention encompasses a method, comprising: receiving a request that indicates at least a portion of an activity period to be associated with a multicarrier apparatus; generating a message to confirm recognition of the at least a portion of the activity period; and broadcasting the message over a communication medium. At least one effect of the foregoing method is that the multicarrier apparatus is able to confirm by way of the broadcast message that it may enter the activity period knowing that other multicarrier apparatuses are aware that it will be in the activity period.

[0021] In an embodiment of the method according to the invention in the second aspect, the at least a portion of the activity period is an active period in which the multicarrier apparatus is at least capable of receiving data transmitted from another multicarrier apparatus.

[0022] In an embodiment of the method according to the invention in the second aspect, the at least a portion of the activity period is an inactive period in which the multicarrier apparatus is at least unable to receive data transmitted from another multicarrier apparatus.

[0023] In an embodiment of the method according to the invention in the second aspect, the request that indicates the activity period includes a parameter specifying a start of an inactive period or an active period associated with the multicarrier apparatus. In an embodiment, the request that indicates the activity period includes another parameter specifying a duration of the inactive period or the active period associated with the multicarrier apparatus.

[0024] In an embodiment of the method according to the invention in the second aspect, the request that indicates the activity period includes a parameter specifying a duration of an inactive period or active period associated with the multicarrier apparatus.

[0025] In an embodiment of the method according to the invention in the second aspect, the request that indicates the activity period includes a first parameter specifying a cycle identifier indicating a cycle in which the activity period is to commence and a second parameter indicating a time duration of the activity period. At least one effect of the foregoing method is that the multicarrier apparatus may enter a power saving mode during the activity period.

[0026] In an embodiment of the method according to the invention in the second aspect, the request that indicates the activity period includes a first parameter specifying a time instance identifier associated with a cycle, the time instant identifier indicating a start of an active or inactive period, and a second parameter indicating a time duration or stop time of the active or inactive period. At least one effect of the foregoing method is that the multicarrier apparatus may enter a power saving mode during the activity period. A further effect is that the time instance identifier enables granular identification of at least a portion of the activity period.

[0027] In a third aspect the invention encompasses an apparatus, comprising: a controller; and a storage coupled to the controller and including instructions to generate at least one message for communication on a communication medium when executed by the controller, the at least one message to include: a first parameter, the first parameter identifying a start of a first portion of an activity period associated with the multicarrier apparatus; and a second parameter, the second parameter identifying a duration of the first portion of the activity period associated with the multicarrier apparatus. At least one effect of the foregoing apparatus is that the multicarrier apparatus may enter a power saving mode during the activity period. At least another effect of the foregoing apparatus is that other multicarrier apparatuses may be aware that the apparatus is the activity period and refrain from transmitting data to the apparatus during the period.

[0028] In an embodiment of the apparatus according to the invention in the third aspect, the at least one message is to further include a third parameter, the third parameter identifying a second portion of the activity period associated with the multicarrier apparatus, the second portion of the activity period to occur following the first portion of the activity period. In an embodiment, the first portion of the activity period is one or more cycles, or time slots, or time fractions within a cycle in which the multicarrier apparatus is to be inactive and the second portion of the activity period is one or more time slots or cycles in which the mu t carr er apparatus is to be active. In an embodiment, the first portion of the activity period is one or more cycles, or time slots, or time fractions within a cycle in which the multicarrier apparatus is to be active and the second portion of the activity period is one or more cycles, or time slots, or time fractions within a cycle in which the multicarrier apparatus is to be inactive.

[0029] In an embodiment of the apparatus according to the invention in the third aspect, the first portion of the activity period is one or more cycles, time slots, or time fractions within a cycle in which the multicarrier apparatus is to be inactive, the multicarrier apparatus to be in a low-power mode or a full-power mode at least during the first portion of the activity period.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference number in different instances in the description and the figures may indicate similar or identical items.

[0031] FIG. 1 illustrates an exemplary communication arrangement that employs a plurality of multicarrier apparatuses. In one implementation, the multicarrier apparatuses are Orthogonal Frequency Division Multiplexing (OFDM) apparatuses capable of implementing the described power management procedures. [0032] FIG. 2 illustrates four exemplary Power Spectrum Density (PSD) spectrums. A profile employed by a high-profile device may implement either of the high-profile PSD spectrums. While a profile employed by a low-profile device may implement either of the low-profile PSD spectrums.

[0033] FIG. 3 illustrates a number of communication cycles, or Media Access Control (MAC) cycles, that divide a communication stream. In one implementation, a multicarrier controller apparatus may be responsible for dividing the communication stream into the illustrated communication cycles.

[0034] FIG. 4 illustrates an exemplary transceiver apparatus that may be used as a transmitting and receiving apparatus in a multicarrier arrangement or system. The multicarrier apparatuses and multicarrier controller apparatus illustrated in FIG. 1 may be implemented in the same or similar manner as the exemplary transceiver apparatus.

[0035] FIG. 5 is a flow diagram of a procedure useable to enable a multicarrier apparatus to specify a particular activity period and reliably enter a power saving mode.

DETAILED DESCRIPTION

[0036] At least one implementation herein enables a multicarrier apparatus to define an activity period, which may include one or more inactive periods. Time periods not defined as inactive periods are considered as active periods. During active periods the multicarrier apparatus is expected to transmit and receive frames. During inactive periods the multicarrier apparatus is not expected to receive any frames. The multicarrier apparatus may enter a power saving mode during one or more inactive periods, or simply remain in a full or normal power mode during the one or more inactive periods. The multicarrier apparatus may report the activity period to a multicarrier controller apparatus, which is charged with assigning time slots (e.g., transmission opportunities) and/or communication cycles to a plurality of multicarrier apparatuses interfaced therewith. During the activity period defined by the multicarrier apparatus, the controller apparatus may choose not to assign time slot(s) and/or cycle(s) to the multicarrier apparatus. Moreover, the controller apparatus may broadcast a message to the plurality of multicarrier apparatus that indicates that the multicarrier apparatus will not be accepting transmissions during the inactive period. The foregoing process reduces bandwidth waste and enables the multicarrier apparatus to enter a dormant state over the defined inactive period.

[0037] Although certain effects are mentioned in connection with various embodiments described herein, it should be appreciated that such effects as well as other effects may be relevant to all embodiments of the invention.

Exemplary Communication Arrangement

[0038] FIG. 1 illustrates an exemplary communication arrangement 100 that employs at least two multicarrier apparatuses or nodes 102 and 104. The exemplary communication arrangement 100 may also employ a multicarrier controller apparatus or controller node 106. In one implementation, the multicarrier apparatuses 102, 104 and 106 are Orthogonal Frequency Division Multiplexing (OFDM) apparatuses capable of implementing the herein described power management procedures.

[0039] The multicarrier apparatuses 102, 104 and 106 may communicate through a communication channel 108. The communication channel 108 may be realized as a wireless communication medium, a wireline communication medium (e.g., coaxial cable, twisted pair of copper wires, power line wiring, optical fiber, etc.), or combinations thereof. Accordingly, the multicarrier apparatuses 102, 104 and 106 may include structure and functionality that enable signal communication over such medium. Such structure and functionality may include one or more antennas, integrated wireline interfaces, and the like. Depending on the implementation, the multicarrier apparatuses 102, 104 and 106 may communicate with one another directly (peer-to-peer mode) or the multicarrier apparatuses 102 and 104 may communicate via the controller apparatus 106.

[0040] In one implementation, the exemplary communication arrangement 100 may be a home network and the multicarrier controller apparatus 106 may be an access point of the home network. For example, in the implementation the controller apparatus 106 may be a residential gateway that distributes broadband services to the multicarrier apparatuses 102 and 104. The multicarrier apparatuses 102 and 104 may be associated with digital content destinations in the home, but may also be associated with digital content sources, such as digital video recorders (DVR), computers providing streaming video, televisions, entertainment centers, and the like.

[0041] Furthermore, the multicarrier apparatuses 102, 104 and 106 may be enabled to communicate using packet-based technology (e.g., ITU G.hn, HomePNA, HomePlug® AV and Multimedia over Coax Alliance (MoCA)) and xDSL technology. Such xDSL technology may include Asymmetric Digital Subscriber Line (ADSL), ADSL2, ADSL2+, Very high speed DSL (VDSL), VDSL2, G.Lite, and High bit rate Digital Subscriber Line (HDSL). In addition, the multicarrier apparatuses 102, 104 and 106 may be enabled to communicate using IEEE 802.11 and IEEE 802.16 (WiMAX) wireless technologies.

[0042] Signals exchanged between the multicarrier apparatuses 102, 104 and 106 may include multicarrier symbols that each include a plurality of tones or sub-channels. Each of the tones within a multicarrier symbol may have data bits modulated thereon that are intended for delivery from one of the multicarrier apparatuses 102, 104 and 106 to another.

[0043] In one implementation, the multicarrier apparatuses 102 and 104 are high-profile devices. A high-profile device may be considered a device operating using a profile that has a higher bandwidth relative to a low-profile device. The profile of a given device may be a band plan that specifies multicarrier modulation parameters such as the range of frequency, sub-carrier spacing, cyclic prefix, and so on. The multicarrier apparatuses 102 and 104 may establish a communication link that enables exchange of packets between the apparatuses 102 and 104. In another implementation, the apparatuses 102 and 104 are low-profile devices. A low-profile device may be considered a device operating using a profile that has a lower bandwidth relative to a high-profile device. The multicarrier controller apparatus 106 may be a high or low-profile device. A low-profile device can communicate directly to a high-profile device as long as two profiles share the common frequency region. In general, the multicarrier controller apparatus 106 may manage traffic between the multicarrier apparatuses 102 and 104. However, the apparatuses 102 and 104 may also include functionality that enables them to manage their own communications and/or manage communications of other multicarrier apparatuses.

[0044] The multicarrier apparatuses 102, 104 and 106 may operate using various power modes. Such power modes may include (1) Full-power Mode (FM), which is a normal mode of operation in which the maximum defined bit-rate is supported, and power consumption is limited only the Power Spectrum Density (PSD) ceiling; (2) Low-power Mode(s) (LM), where theses modes support a limited data rate while consuming less power than the FM; and (3) Idle Mode (IM), where a device is switched on, but no traffic is transmitted or expected to be received thereby. The modes defined herein are exemplary, as other power modes may also be implemented by the multicarrier apparatuses 102, 104 and 106. For example, FMs and LMs may also employ PSD ceiling modification to lower power consumption of a multicarrier apparatus. For example, a FM may use a consistent bandwidth of 100 MHz, but lower the PSD to save power. In another example, an LM may reduce bandwidth to 50 MHz and also lower PSD to save additional power. A low-profile device operating in FM consumes less power than a high-profile device operating in FM.

[0045] FIG. 2 illustrates four exemplary PSD spectrums. A profile employed by a high-profile device may implement either PSD spectrum 202 or 204. While a profile employed by a low-profile device may implement either PSD spectrum 206 or 208. Although the PSD spectrums 202 and 204 are illustrated as having a bandwidth of 100 MHz, other bandwidth values may also be used. Similarly, the PSD spectrums 206 and 208 are illustrated as having a bandwidth of 50 MHz, but other bandwidth values may be used as well.

[0046] FIG. 3 illustrates a number of communication cycles, or Media Access Control (MAC) cycles, that divide a communication stream 300. In one implementation, the multicarrier controller apparatus 106 may be responsible for dividing the communication stream into the illustrated communication cycles. FIG. 3 shows a portion of the communication stream 300 that includes three cycles 302 (i.e., MAC cycle M, MAC cycle M+1 , and MAC cycle M+2). The multicarrier controller apparatus 106 may transmit a time marker, or beacon signal, and a Media Access Plan (MAP) message 304 at the start of each cycle 302. Each MAP message 304 may dictate a transmit sequence in which the multicarrier apparatuses 102 and 104 are to transmit for the associated cycle 302. Accordingly, a MAP message 304 may dictate how much bandwidth is allocated to each of the multicarrier apparatuses 102 and 104 for a given cycle 302. The MAP message 304 may be transmitted at the beginning of each MAC cycle 302 as illustrated in FIG. 3. However, MAP message 304 may be transmitted in the middle of previous MAC cycle 302 as long as it is transmitted before the start of the associated cycle 302 that the MAP message 304 describes.

[0047] As is illustrated in FIG. 3, each cycle 302 may include a number of time slots 306. These time slots 306 are often referred to as transmission opportunities. Time slots 306 also can be referred to as smaller time slots or time units defined within a transmission opportunity. The starting time and duration of each of the time slots 306, and which multicarrier apparatuses may occupy the time slots 306, may be specified in the MAP message 304. For example, for the cycle M+1 302, the MAP message 304 may specify N time slots 306; where N could range from 1 up to a certain maximum value depending on the time resolution and duration of the cycle M+1 302. Although FIG. 3 shows an example where adjacent time slots are separated by gaps where all nodes may be substantially silent, in other examples the time slots may directly abut one another.

[0048] One or more messages (e.g., data packets) may be transmitted during each time slot 306. During TSN 306, for example, one or more messages may be transmitted, where the number of messages may depend on a time resolution and duration of the TS_N 306. The one or more messages within TSN 306 may be transmitted relative to the multicarrier apparatuses 102 and 104 in several ways.

[0049] In one implementation, a time slot may be a dedicated transmission opportunity, and all the messages during the dedicated transmission opportunity will be transmitted from a single multicarrier apparatus assigned thereto. For example, the TS_N 306 may be reserved exclusively for transmissions by the multicarrier apparatus 102. Therefore, during the TSN 306 the multicarrier apparatus 102 may transmit one or more messages to be received by the multicarrier controller apparatus 106 and/or other multicarrier apparatuses, such as the multicarrier apparatus 104. When the multicarrier apparatus 102 is transmitting during the TSN 306, the multicarrier controller apparatus 106 and the other multicarrier apparatuses, such as the multicarrier apparatus 104, are substantially silent, so as not to interfere with the transmissions of the multicarrier apparatus 102. In this way, a node can transmit its required data during a dedicated transmission opportunity without the other nodes interfering with its communication.

[0050] In another implementation, a time slot may be a shared transmission opportunity. During a shared transmission opportunity, messages may be transmitted from a plurality of multicarrier apparatuses. For example, the TS_N+i 306 may be reserved for transmissions by the multicarrier apparatuses 102 and 104. In one implementation, the multicarrier apparatuses 102 and 104 assigned to the shared transmission opportunity may be assigned timeslots within the shared transmission opportunity, but in other implementations the multicarrier apparatuses 102 and 104 may dynamically compete for the available bandwidth in the shared transmission opportunity according to a set of rules dictated by the multicarrier controller apparatus 106.

[0051] In certain situations, a particular multicarrier apparatus 102 or 104 may not need to transmit and/or receive data (i.e., media access) during a given time slot or transmission opportunity. Nonetheless, absent information to the contrary, the multicarrier controller apparatus 106 may assign media access to such an inactive multicarrier apparatus 102 or 104. This may waste one or more time slots that could be assigned to other multicarrier apparatuses, and may cause an otherwise inactive multicarrier apparatus 102 or 104 to consume unnecessary power. Also, the receiver portion of the inactive multicarrier apparatus 102 or 104 needs to consume unnecessary power by listening to the line for possible transmission destined to it where there is no such transmission is present. The implementations and procedures herein are designed to mitigate assigning time slots or communication cycles to inactive multicarrier apparatuses, which will enable such inactive multicarrier apparatuses to enter a power saving mode.

[0052] FIG. 4 illustrates an exemplary transceiver apparatus 400 that may be used as a transmitting and receiving apparatus in a multicarrier arrangement or system. The multicarrier apparatuses 102, 104 and 106 illustrated in FIG. 1 may be implemented in the same or similar manner as the exemplary transceiver apparatus 400.

[0053] The transceiver apparatus 400 may include a transmitter 402 that incorporates a number of different elements. For example, the transmitter 402 may include an encoder 404, a modulator 406, a filter 408, an interface 410 and a controller 412. As used herein, the term "controller" is meant generally to include all types of digital processing devices including, without limitation, digital signal processors (DSPs), reduced instruction set computers (RISC), general-purpose (CISC) processors, microprocessors, gate arrays (e.g., FPGAs), PLDs, reconfigurable compute fabrics (RCFs), array processors, secure microprocessors, and application-specific integrated circuits (ASICs). Such digital processors may be contained on a single unitary IC die, or distributed across multiple components. [0054] The encoder 404 may be capable of receiving data that is for communication to a receiving device coupled to the transceiver apparatus 400 via a wireless or wireline medium 416. More specifically, the encoder 404 may be capable of translating incoming data bit streams into in-phase and quadrature components for each of the plurality of tones. The encoder 404 may be arranged to output a number of symbol sequences that are equal to the number of tones available to the system. The modulator 406 may be capable of receiving symbol sequences to produce a modulated signal in the form of a discrete multi-tone signal. The modulator 406 may pass the modulated signal to the filter 408 to undergo various filtering and then the filtered signal may be passed to the interface 410 for communication over the medium 416 to a receiving device.

[0055] The transceiver apparatus 400 may also include a receiver 418 that is capable of receiving modulated multi-tone signals communicated over the medium 416 from a transmitting device. The receiver 418 may include an interface 420, a filter 422, a demodulator 424, a decoder 426 and a controller 428. Alternatively, the transceiver apparatus 400 may implement a single controller, instead of the illustrated controllers 412 and 428. Signals received by the receiver 418 may be passed to the filter 422 via the interface 420. After received signals undergo filtering by way of the filter 422, the filtered signals may be demodulated by the demodulator 424. The demodulated signals may be passed to and processed by the decoder 426. The decoder 426 produces data bit streams for consumption by a computing device, or the like. Effectively, the demodulator 424 and the decoder 426 perform the opposite functions of the modulator 406 and the encoder 404, respectively.

[0056] Referring collectively to FIGS. 1-4, as will be appreciated, the communication arrangement 100 may operate such that nodes (e.g., multicarrier apparatuses 102 and 104) that are hidden from one another will transmit during different time slots or at different times during the same time slot. During network operation, the nodes monitor messages on the channel 108 (e.g., the medium communication 416) and identify the other nodes from which the messages were transmitted. For example, multicarrier apparatuses 102 may use its receiver 418 to continuously or intermittently "listen" to messages on the communication medium 416. The multicarrier apparatus 102 may then determine whether the receiver 418 "heard" a message from the multicarrier apparatus 104, and/or one or more other multicarrier apparatuses.

[0057] After monitoring, the nodes may send information messages to the multicarrier controller apparatus 106. Each information message may indicate the other nodes that a monitoring node "heard" during monitoring. In one implementation, the controller 412 of the multicarrier apparatus 102 may instruct the transmitter 402 to transmit an information message indicating that it heard messages from the multicarrier apparatus 104, and/or one or more other multicarrier apparatuses. In one embodiment, these information messages may be transmitted in bitmap format, where certain one or more bits specify whether or not the transmitting node detected a message from a different node.

[0058] In one implementation, an information message from a node may include one or more parameters that specify one or more time slots and/or cycles in which the node will be inactive. In another implementation, such parameters may be sent in a separate message, or another communication from the node. The node will become active again after the inactive period.

[0059] In another implementation, an information message from a node may include one or more parameters that specify one or more time slots and/or cycles in which the node will be inactive. In another implementation, such parameters may be sent in a separate message, or another communication from the node. The parameters sent by the node may include one or more parameters that specify a number of time slots and/or cycles that the node will be inactive, and a number of time slots and/or cycles that the node will be active after the inactive period. An additional parameter sent by the node may specify a particular time slot and/or cycle in which the inactive period will commence.

[0060] In yet another implementation, an information message from a node may include one or more parameters that specify one or more time slots and/or cycles in which the node will be active. In another implementation, such parameters may be sent in a separate message, or another communication from the node. The parameters sent by the node may include one or more parameters that specify a number of time slots and/or cycles that the node will be active, and a number of time slots and/or cycles that the node will be inactive after the active time slots and/or cycles. An additional parameter sent by the node may specify a particular time slot and/or cycle in which the active period will commence. Other possible implementations for identifying active and inactive time slots or cycles will be discussed in greater detail in the following.

[0061] The multicarrier controller apparatus 106 may use its receiver 418 to receive the information messages from the multicarrier apparatuses 102 and 104, and/or other nodes associated with the communication arrangement 100. The controller of the multicarrier controller apparatus 106 may then determine which nodes can (and cannot) "hear" one another. The information may be used by the multicarrier controller apparatus 106 to assign nodes in the communication arrangement 100 to one or more time slots or transmission opportunities associated with one or more cycles. The multicarrier controller apparatus 106 may use a control message, such as the MAP message 304, to convey time slot assignment information to the multicarrier apparatuses 102 and 104, and/or other nodes associated with the communication arrangement 100. In addition, the multicarrier controller apparatus 106 may use the control message, or another message, to identify those nodes that will be active and/or inactive in a given cycle. Nodes in an inactive state may be in a power saving mode that prevents reception of data, or implement one of a number of low-power profiles.

[0062] The multicarrier apparatuses 102 and 104, and/or other nodes, may receive the control message via their receivers 418. The multicarrier apparatuses 102 and 104, and/or other nodes, may then use their controllers to parse the control message and configure their transmitter 402 to transmit in an assigned time slot or transmission opportunity associated with one or more cycles. The multicarrier apparatuses 102 and 104, and/or other nodes, may also use the information of the control message to determine which nodes will be inactive and/or active in a given time slot(s) and/or cycle(s). Based on this information, the multicarrier apparatuses 102 and 104, and/or other nodes, may use their controllers to configure their transmitter 402 to limit transmitting data to active or available nodes.

[0063] Exemplary procedures are described below. It should be understood that certain acts need not be performed in the order described, and may be modified, and/or may be omitted entirely, depending on the circumstances. The acts described may be implemented and executed by a computer, processor or other computer device, such as a wireless or wireline device, based on instructions stored on one or more computer-readable storage media associated with the wireless or wireline device and/or associated with other storage media not co-located with the device. The computer-readable storage media can be any available media that can be accessed by a computer device to implement the instructions stored thereon. As used herein, the term "instructions", "computer program" or "software" is meant to include any sequence or human or machine cognizable acts which perform a function. The exemplary procedures and acts may be rendered in virtually any programming language or environment including, for example, C/C++, Fortran, COBOL, PASCAL, assembly language, markup languages (e.g., HTML, SGML, XML, VoXML), and the like, as well as object-oriented environments such as the Common Object Request Broker Architecture (CORBA), Java™ (including J2ME, Java Beans, etc.), Binary Runtime Environment (BREW), and the like. Furthermore, the disclosed exemplary procedures and associated acts may be hardware and firmware as well, or alternatively as some combination thereof.

[0064] FIG. 5 is a flow diagram of a procedure 500 useable to enable a multicarrier apparatus to specify a particular activity period. In one implementation, the activity period may be a single inactive period associated with the multicarrier apparatus in which the apparatus is in a reduced power mode. In another implementation, the activity period may contain multiple alternating active and inactive periods. The procedure is compatible with apparatuses, elements and wireless networks illustrated in and describe herein, as well as entities and devices other than those illustrated and discussed herein. The procedure 500 may be used to enable a multicarrier apparatus (e.g., node) to specify one or more activity periods in which it may be in a FM and periods in which it may be in one of various LMs. Furthermore, the procedure 500 may be used to enable a node to specify one or more inactive periods in which it will not be available to receive data from other nodes, but otherwise remain in FM. [0065] At Act 502, a node determines that specifying an activity period may be prudent. In one implementation, the node may determine that entering a power saving mode (e.g., an LM) for a period may be beneficial based on bandwidth requirements, past and/or future data transmissions, reception requirements, and so on. In another implementation, the node may determine that being unavailable for a period may be beneficial based on bandwidth requirements, past and/or future data transmissions, reception requirements, and so on. In the second example, the node may or may not enter a power saving mode. In yet another example, the node may determine based on the request received from another node (e.g., source node) that transmissions will be reduced or ceased. In yet another example, the node may determine based on the traffic characteristics (e.g., very low-rate burst traffic such as VoIP). The determination of Act 502 may occur during runtime, at the time the node is admitted to the network, or at flow setup.

[0066] At Act 504, the node may generate one or more parameters that define the activity period. The activity period may contain a single inactive period, or a single inactive period followed by a single active period, or a single active period followed by a single inactive period, or a series of alternating active and inactive periods. The activity period may be specified by the start time and the stop time, or alternatively the start time and the duration. Specifying the start time of the activity period may be omitted. If the start time is not specified, a controller node may specify the start time. Each individual inactive (active) period within the activity period may be specified by the start time and the stop time, or alternatively by the start time and the duration. These points can be expressed in terms of MAC cycle identification number, time slot identification number, time slot measurement units, time, or any combinations of above. These points can be expressed in absolute scale or relative scale with respect to one or more reference points.

[0067] In one implementation, the node may use one or more of the following parameters (M₇-, Nι_(A), N_A(ij) for defining an activity period, which may include inactive and active time slots in one or more MAC cycles, where:

• MT is the MAC cycle number (or cycle identifier) from which the period takes effect;

• Ni_(A) is the number of inactive (active) MAC cycles after Mτ-th MAC cycle; this value determines the inactive (active) period between successive inactive (active) MAC cycles - during this time, the transmitter and/or the receiver of the node may be dormant if the period is inactive, or activated if the period is active; and

• N_A(i₎ is the number of active (inactive) MAC cycles after Nι_(A) MAC cycles from /WHh MAC cycle; this value determines the active (inactive) period after the transmitter and/or the receiver of the node become active - this value is meaningless if Λ/_/W = 0.

[0068] In another implementation, alternating active and inactive periods may be characterized by the parameters >AM/4CSTART and AMACQUR (IMACSTART and M4CDUR) which denote the start time and duration of active (inactive) periods, respectively. Note that AMACSTARΎ (0 = IMACSTART (t-1) + IMACQUR (t-1), and IMACSTART (0 = AMACSTART {t-1) + AMACom (t-1) where t denotes an arbitrary index representing the time-varying nature of active and inactive periods. Although the parameters in the foregoing example are expressed in terms of MAC cycle sequence number, they can also be expressed in terms of time slot units, or absolute time. [0069] In yet another implementation, the parameters may be defined by a fixed duration of active and inactive periods (AMACDUR, IMACDUR) that may be specified during network admission or at the flow setup. This approach does not require runtime message exchanges between a node and the multicarrier controller apparatus (e.g., controller node). Moreover, in this implementation, AMACSTART and /MACSTART do not need to be specified. The start time of the activity period may be notified by the multicarrier controller once the schedule is finalized.

[0070] In yet another implementation, the node may determine the parameters associated with a next inactive period during a current active period. This implementation may require the node to determine, during an active period, when a next inactive period will start (IMACSΎ_ARΎ) and how long the inactive period will last (IMACDUR)- IMACSTART and IMACDUR can be expressed in terms of MAC cycle identification number, time slot identification number, time slot measurement units, time, or any combinations of the above. These points can be expressed in absolute scale or relative scale respect to one or more reference points.

[0071] In yet another implementation, the node may determine the parameters associated with a next inactive period during a current active period. This implementation may require the node to determine, during an active period, when a next inactive period will start {IMAC_START) and when it will end (IMACSTOP)- IMACSTART and IMACSTOP can be expressed in terms of MAC cycle identification number, time slot identification number, time slot measurement units, time, or any combinations of above. These points can be expressed in absolute scale or relative scale respect to one or more reference points.

[0072] In yet another implementation, absolute time duration may be used to define parameters associated with inactive and active periods. In particular, the following parameters (M_τ, Tι_(A), T_Λrø) may be used for defining an activity period, which may includes inactive and active time slots in a plurality of MAC cycles, where:

• Ti_(A) is the inactive (active) MAC cycle duration after MHh MAC cycle; this value determines the inactive (active) period between successive active (inactive) time slots; during this time, both the transmitter and/or the receiver of the node may be dormant if the period is inactive, or activated if the period is active; and the value may be in terms of absolute time, or number of common clocks; and

• T_A(i₎ is that active (inactive) MAC cycle duration after T,_w; this value determines the active (inactive) period after the transmitter and/or the receiver of the node become active; this value is meaningless if TI₍A₎ = 0.

[0073] At Act 506, the node generates a message that includes one or more parameters that define an activity period. In one implementation, the parameter is a cycle identifier that specifies an initial cycle, or time slot within a cycle, or a time instance within a cycle in which the node will be in an LM or otherwise be unavailable to receive data from other nodes. In another implementation, the message also includes one or more parameters that identify a number of one or more cycles, or one or more time slots within the cycles, or one or more time instances within the cycles that the node will be in the LM or unavailable. In yet another implementation, the message also includes a parameter that identifies a number of one or more cycles, or one or more time slots within the cycles, or one or more time instances within the cycle that the node will be in FM mode or available after the LM or unavailable period ends. [0074] In one implementation, the parameter is a cycle identifier that specifies an initial cycle, or time slot within a cycle, or a time instance within a cycle in which the node will be in a FM or otherwise be available to receive data from other nodes. In another implementation, the message also includes one or more parameters that identify a number of one or more cycles, or one or more time slots within the cycles, or one or more time instances within the cycles that the node will be in FM or available. In yet another implementation, the message also includes a parameter that identifies a number of one or more cycles, or one or more time slots within the cycles, or one or more time instances within the cycle that the node will be in LM or unavailable after the FM or available period ends.

[0075] The message generated at Act 506 may be part of a payload portion of a packet 508 for communication on a communication channel or medium (e.g., medium 416). Moreover, the one or more parameters of the message may be defined by a predetermined number of message bits useable for identifying a period of activity (e.g., inactive and/or active) associated with the node. Although packet 508 is illustrated as including the message in the payload portion, the message may alternatively be included in a packet that includes a preamble (PR) and a header (HD) (e.g., no payload portion), where the message is included in the HR.

[0076] At Act 510, a multicarrier controller apparatus (e.g., controller node) receives the message generated at Act 506. At Act 512, the controller node determines if the activity period requested by the node is acceptable. If the controller node approves of the requested activity period, At Act 514, the controller node may generate a packet 516 that includes a message specifying inactive and/or active periods associated with the node. The message may be broadcast to the requesting node, as well as other nodes associated with the communication arrangement. In , message and the particulars of the inactive and/or active periods may be specified in an Auxiliary Information field of the MAP message. In another implementation, the message broadcast by the controller node is a separate message and the particulars of the inactive and/or active periods may be specified in the message body. Although packet 516 is illustrated as including the message in the payload portion, the message may alternatively be included in a packet that includes a preamble (PR) and a header (HD) (e.g., no payload portion), where the message is included in the HR. However, if the controller node does not approve of the requested activity, at Act 514, the controller node may generate a packet 518 that includes a message specifying that the requested inactive and/or active periods are not approved. Again, although packet 518 is illustrated as including the message in the payload portion, the message may alternatively be included in a packet that includes a preamble (PR) and a header (HD) (e.g., no payload portion), where the message is included in the HR.

[0077] At Act 520, the packet 516 is received, the node initiates the requested activity period at the appropriate moment. For example, the node may enter an LM at the beginning of the next cycle or time slot. Alternatively, the node may remain in a current power mode until a requested inactive period is to commence. Or, the node may simply remain in a current power mode at the commencement of the inactive period, but operate under the expectation that other nodes will not attempt transmission of data thereto during the node's inactive period. Alternatively, if the packet 518 is received at Act 520, the node will not initiate the activity period requested in the message generated at Act 506. [0078] While the exemplary implementations illustrated herein may show the various components of the arrangement collocated, it is to be appreciated that the various components of the arrangement may be located at distant portions of a distributed network, such as a communications network and/or the Internet, or within a dedicated secure, unsecured and/or encrypted arrangement. Thus, it should be appreciated that the components of the arrangements may be combined into one or more apparatuses, such as a modem, or collocated on a particular node of a distributed network, such as a telecommunications network. Moreover, it should be understood that the components of the described arrangements may be arranged at any location within a distributed network without affecting the operation of the arrangements. For example, the various components can be located in a Central Office modem (CO, ATU-C, VTU-O), a Customer Premises modem (CPE, ATU-R, VTU-R), an xDSL management device, or some combination thereof. Similarly, one or more functional portions of the arrangement may be distributed between a modem and an associated computing device.

[0079] The above-described arrangements, apparatuses and methods may be implemented in a software module, a software and/or hardware testing module, a telecommunications test device, a DSL modem, an ADSL modem, an xDSL modem, a VDSL modem, a linecard, a G.hn transceiver, a MOCA transceiver, a Homeplug transceiver, a powerline modem, a wired or wireless modem, test equipment, a multicarrier transceiver, a wired and/or wireless wide/local area network system, a satellite communication system, network-based communication systems, such as an IP, Ethernet or ATM system, a modem equipped with diagnostic capabilities, or the like, or on a separate programmed general purpose computer having a communications device or in conjunction with any of the following communications protocols: CDSL₁ ADSL2, ADSL2+, VDSL1, VDSL2, HDSL, DSL Lite, IDSL, RADSL, SDSL, UDSL, MOCA, G.hn, Homeplug or the like.

[0080] Additionally, the arrangements, procedures and protocols of the described implementations may be implemented on a special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit element(s), an ASIC or other integrated circuit, a digital signal processor, a flashable device, a hard-wired electronic or logic circuit such as discrete element circuit, a programmable logic device such as PLD, PLA, FPGA, PAL, a modem, a transmitter/receiver, any comparable device, or the like. In general, any apparatus capable of implementing a state machine that is in turn capable of implementing the methodology described and illustrated herein may be used to implement the various communication methods, protocols and techniques according to the implementations.

[0081] Furthermore, the disclosed procedures may be readily implemented in software using object or object-oriented software development environments that provide portable source code that can be used on a variety of computer or workstation platforms. Alternatively, the disclosed arrangements may be implemented partially or fully in hardware using standard logic circuits or VLSI design. The communication arrangements, procedures and protocols described and illustrated herein may be readily implemented in hardware and/or software using any known or later developed systems or structures, devices and/or software by those of ordinary skill in the applicable art from the functional description provided herein and with a general basic knowledge of the computer and telecommunications arts.

[0082] Moreover, the disclosed procedures may be readily implemented in software that can be stored on a computer-readable storage medium, executed on programmed general-purpose computer with the cooperat on o a controller an memory, a special purpose computer, a microprocessor, or the like. In these instances, the arrangements and procedures of the described implementations may be implemented as program embedded on personal computer such as an applet, JAVA® or CGI script, as a resource residing on a server or computer workstation, as a routine embedded in a dedicated communication arrangement or arrangement component, or the like. The arrangements may also be implemented by physically incorporating the arrangements and/or procedures into a software and/or hardware system, such as the hardware and software systems of a test/modeling device.

[0083] The implementations herein are described in terms of exemplary embodiments. However, it should be appreciated that individual aspects of the implantations may be separately claimed and one or more of the features of the various embodiments may be combined.

[0084] For the purposes of this disclosure and the claims that follow, the terms "coupled" and "connected" have been used to describe how various elements interface. Such described interfacing of various elements may be either direct or indirect. Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as preferred forms of implementing the claims. The specific features and acts described in this disclosure and variations of these specific features and acts may be implemented separately or may be combined.

Claims

1. A method, comprising: determining an activity period to be associated with a multicarrier apparatus; generating a message that includes at least one parameter that identifies at least a portion of the activity period; and transmitting the message.

2. The method according to claim 1 , wherein the at least one parameter that identifies the at least a portion of the activity period is a cycle identifier, the cycle identifier specifying an initial cycle in which the multicarrier apparatus will enter a first mode.

3. The method according to claim 2, wherein the generated message further includes another parameter that identifies a number of one or more cycles in which the multicarrier apparatus will be in the first mode.

4. The method according to claim 3, wherein the generated message further includes yet another parameter that identifies a number of zero, one, or more cycles in which the multicarrier apparatus will be in a second mode, the number of zero, one, or more cycles in which the multicarrier apparatus will be in the second mode to occur after the number of one or more cycles in which the multicarrier apparatus will be in the first mode.

5. The method according to claim 1 , wherein the at least one parameter that identifies the at least a portion of the activity period is a time instance identifier, the time instance identifier specifying a point in time within a cycle in which the multicarrier apparatus will enter a first mode.

6. The method according to claim 1 , wherein the at least one parameter that identifies the at least a portion of the activity period is a number of one or more cycles in which the multicarrier apparatus is to be in a first mode.

7. The method according to claim 1 , wherein the activity period is a period in which the multicarrier apparatus is in a low-power mode.

8. The method according to claim 1 , wherein the activity period is a period in which the multicarrier apparatus is in a full-power mode.

9. The method according to claim 1 , wherein the activity period is an active period in which the multicarrier apparatus is at least capable of receiving data transmitted from another multicarrier apparatus.

10. The method according to claim 1 , wherein the activity period is an inactive period in which the multicarrier apparatus is at least unable to receive data transmitted from another multicarrier apparatus.

11. The method according to claim 1 , further comprising: receiving a broadcast message confirming the activity period has been acknowledged; and entering a predefined power mode for the activity period.

12. The method according to claim 1 , wherein the at least one parameter that identifies the at least a portion of the activity period is a time slot identifier associated with a cycle, the time slot identifier specifying an initial time slot in which the multicarrier apparatus will enter a first mode.

13. The method according to claim 12, wherein the generated message further includes another parameter that identifies a number of one or more time slots in which the multicarrier apparatus will be in the first mode.

14. The method according to claim 13, wherein the generated message further includes yet another parameter that identifies a number of zero, one, or more time slots in which the multicarrier apparatus will be in a second mode, the number of zero, one, or more time slots in which the multicarrier apparatus will be in the second mode to occur after the number of one or more time slots in which the multicarrier apparatus will be in the first mode.

15. The method according to claim 1 , wherein the activity period is a combination of one or more active periods in which the multicarrier apparatus is at least capable of receiving data transmitted from another multicarrier apparatus and one or more inactive periods in which the multicarrier apparatus is at least unable to receive data transmitted from another multicarrier apparatus.

16. A method, comprising: receiving a request that indicates at least a portion of an activity period to be associated with a multicarrier apparatus; generating a message to confirm recognition of the at least a portion of the activity period; and broadcasting the message over a communication medium.

17. The method according to claim 16, wherein the at least a portion of the activity period is an active period in which the multicarrier apparatus is at least capable of receiving data transmitted from another multicarrier apparatus.

18. The method according to claim 16, wherein the at least a portion of the activity period is an inactive period in which the multicarrier apparatus is at least unable to receive data transmitted from another multicarrier apparatus.

19. The method according to claim 16, wherein the request that indicates the activity period includes a parameter specifying a start of an inactive period or an active period associated with the multicarrier apparatus.

20. The method according to claim 19, wherein the request that indicates the activity period includes another parameter specifying a duration of the inactive period or the active period associated with the multicarrier apparatus.

21. The method according to claim 16, wherein the request that indicates the activity period includes a parameter specifying a duration of an inactive period or active period associated with the multicarrier apparatus.

22. The method according to claim 16, wherein the request that indicates the activity period includes a first parameter specifying a cycle identifier indicating a cycle in which the activity period is to commence and a second parameter indicating a time duration of the activity period.

23. The method according to claim 16, wherein the request that indicates the activity period includes a first parameter specifying a time instance identifier associated with a cycle, the time instant identifier indicating a start of an active or inactive period, and a second parameter indicating a time duration or stop time of the active or inactive period.

24. A multicarrier apparatus, comprising: a controller; and a storage coupled to the controller and including instructions to generate at least one message for communication on a communication medium when executed by the controller, the at least one message to include: a first parameter, the first parameter identifying a start of a first portion of an activity period associated with the multicarrier apparatus; and a second parameter, the second parameter identifying a duration of the first portion of the activity period associated with the multicarrier apparatus.

25. The multicarrier apparatus according to claim 24, wherein the at least one message is to further include a third parameter, the third parameter identifying a second portion of the activity period associated with the multicarrier apparatus, the second portion of the activity period to occur following the first portion of the activity period.

26. The multicarrier apparatus according to claim 24, wherein the first portion of the activity period is one or more cycles, time slots, or time fractions within a cycle in which the multicarrier apparatus is to be inactive, the multicarrier apparatus to be in a low-power mode or a full-power mode at least during the first portion of the activity period.

27. The multicarrier apparatus according to claim 25, wherein the first portion of the activity period is one or more cycles, or time slots, or time fractions within a cycle in which the multicarrier apparatus is to be inactive and the second portion of the activity period is one or more time slots or cycles in which the multicarrier apparatus is to be active.

28. The multicarrier apparatus according to claim 25, wherein the first portion of the activity period is one or more cycles, or time slots, or time fractions within a cycle in which the multicarrier apparatus is to be active and the second portion of the activity period is one or more cycles, or time slots, or time fractions within a cycle in which the multicarrier apparatus is to be inactive.