CN100488151C - Method and apparatus for non-centralized network bandwidth management - Google Patents

Abstract

A system and method of providing distributed video and/or audio communication over a network, such as a power-line communications (PLC) network. By way of example, the network is divided into periodic cycles wherein each cycle comprises a number of time slots. The timing of the cycles is determined by a cycle master that assumes the position when it desires to send a transmission and is unable to detect valid cycles on the network. A portion of each cycle is reserved for the transmission of asynchronous data, the remainder being utilized for isochronous streams. Before transmitting a new stream a transmitter wins one or more open slots by arbitration, wherein the winner is selected based on the priority of the stream to be sent. Transmitters may obtain extra slots to improve quality, integrity, or security of the stream. The mechanisms of the invention are compatible with legacy CDMA devices.

Description

The method and apparatus that is used for the decentralized network Bandwidth Management

The cross reference of related application

[0001] the application requires the preference of the U.S. Provisional Application sequence number 60/479406 of submission on June 18th, 2003, and is by reference that it is intactly incorporated herein.

Statement about the federal funding research and development

[0002] inapplicable

Submit the combination of quoting of data on the CD to

[0003] inapplicable

Be subjected to the points for attention of the data of copyright protection

[0004] part of the data in the patent document is subjected to the copyright protection of the U.S. and other national Authorship Right Law.The copyright owner does not oppose anyone facsimile copy patent document or this patent openly, because it appears in the file that can openly obtain or record of United States Patent (USP) and trademark office, but still keeps all copyrights in others.The copyright owner is in this any right of not abandoning making this patent documentation to maintain secrecy, comprising but be not limited to the right relevant with 37C.F.R. § 1.14.

Background of invention

1. invention field

[0005] in general, the present invention is relevant with network communicating system, and is more particularly, relevant with the method for transfer of data being distinguished order of priority.

2. description of Related Art

[0006] there are two big class networks: wait step network and the network that goes on foot such as non-.IEEE 1394 networks are a kind of typical step networks that wait, and therein, one of device on network management time slot uses.Response is from the request of other device of wanting to send stream, and available time slot is distributed by the time slot manager.In case distribute, transmitter generally can continue to use time slot and do not interrupted by other stream, up to the end of transmission.The primary flow inter-packet gap that transmits by network at receiver side by reconstruct.A significant advantage of communication is that QoS (service quality) is guaranteed fully in the step.

[0007] still, wait the step network to also have some shortcomings.For example, in centralized network, if the time slot manager is disconnected, then another device must be taken over the time slot management, thereby requires each network central means to be equipped with the time slot management function, and this has increased the network equipment cost.In addition, responding device connects or disconnects connection, complete bus reset occurs, disturbs bus communication.Step such as such is controlled at special-purpose noiseless network, as working satisfactorily on the IEEE 1394, but it not too is suitable for being subjected to the network of harsh transmission conditions, for example 802.11 wireless networks or power line network.

[0008] as representative, by this network, traffic carrying capacity often adopts CSMA/CA (carrier sense multiple access/anticollision) mechanism or similar mechanism to control to a kind of typical non-network such as step such as grade by Ethernet.Under CSMA/CA, when one on bus device wished to communicate by letter with another device, transmitter is the carrier wave on the testbus at first.If do not detect carrier wave, then this device begins communication.But if detect carrier wave, then transmitter enters fall-back mode, after certain postpones, attempts this process again.Stand-by period during the rollback generally is randomized, makes two devices of just waiting for can not conflict once more.In traditional CSMA/CA, bus is not controlled by the time slot manager.

[0009] utilize step network such as more non-that advantages and some shortcomings are provided.Advantage be about allow the user freely handle assembly be connected to network or disconnect from it, and do not have the loss of bus reset.Each device does not need to relate to network state, particularly what device to be connected or not to be connected to network.Network interface is simply and cheaply, because do not require the time slot management function.A shortcoming is that (QoS) do not guarantee service quality; When network was busy, device suffered from uncertain latency period.

[0010] many market forces promote the progress of networking.A kind of such strength is the family expenses networking market of expansion, and it has adopted 802.11 wireless standards and HomePlug ^TM1.0 power line network standard.These two kinds of standards all are that Ethernet is equal, and do not guarantee service quality (QoS).Though network standard, as IEEE 1394 guaranteed qos, they are because of limited cable transmission scope, and because cable must for example device wiring one by one between the room of family, so not too be fit to many markets.

[0011] therefore, need the autonomous network communication standard, they provide flexibility and low cost, can support given service quality (QoS) at least a portion of the transmission of passing through network delivery simultaneously.The present invention is a kind of autonomous network, and it satisfies those demands and other demand, and has overcome the defective of the Networking Solutions ﹠ provisioned of previous exploitation.

Summary of the invention

[0012] method and system that a kind of autonomous decentralized network is controlled, the service quality that it is given security are described.System and method of the present invention is well suited for being used for power line communication (PLC) network.

[0013] support being distributed on the network of time slot of various flows transmission independently to determine, wherein crack manager or moderator when not required.Manage to transmit first device of stream on the network and serve as the role of cycle main controller, be network cycle regularly, and all transmitter installations on the network enter arbitration independently so that obtain the time slot of anticipated number.Each transmission cycle preferably is divided into the part that is used for waiting step transmission and asynchronous transmission.Internal clocking difference between the device on the network is accumulation not, and the cycle main controller can be disconnected and do not have an interrupt flow business.

[0014] explained many useful patterns and aspect in the present invention, they are divided into following classification:

[0015] (1) keeps the priority channel bandwidth by adopting pseudo-transmission to fill in the present invention.The cycle main controller adopts pseudo-transmission to fill the not use time slot that goes on foot in the part that waits of transmission cycle, thereby the asynchronous device that prevents lower priority utilizes reserved bandwidth inadequately.Fill the device of leaving over that does not use time slot to allow to utilize in the asynchronous part of transmission cycle, to communicate by letter on the PLC network in the reserved bandwidth.Leave over device and can regard do not have configuration to be used for the asynchronous device of controlling by the adaptive bandwidth managing device as.

[0016] (2) segment priority in given priority level.When according to the quantity request time slot of active flow, stream transmission order token, power target value (inferior priority value) is determined order, with this order, stream can obtain time slot in arbitration on given priority, finishes up to stream.For example, digital token is transmitted (promptly from set { 0,1, among the 2...n}), wherein obtains when obtaining time slot preferentially than low order priority numeral.When the stream end occurring, priority is shifted according to token value, wherein the high inferior priority value of its residual current fill order.Token is preferably shared between the server on the virtual net.

[0017] (3) automatic enhanced flow signal.In the present invention, signal strengthens the availability of the bandwidth that responds given priority level and is performed.According to this aspect of the invention, utilize automatically reserved bandwidth do not use part, for example be assigned to given flow priority, as with etc. that related part of step stream so that improve quality, integrality or the fail safe of flowing.Therefore, be not only to adopt pseudo-data to fill not utilized bandwidth part (being time slot), but also with better quality to this stream encryption, wherein guaranteeing more not can loss of data, have bigger fail safe or flow improved combination.

[0018] (4) response condition and reduce bandwidth automatically.But the amount of bandwidth that is used for each stream is at system responsive bandwidth degradation or send the demand of additional streams and reduce automatically when utilizing available bandwidth.All streams or selected stream are through control (if possible), so that reduce its bandwidth usage.Bandwidth constraints also can be loosened when stream finishes, thereby reduces institute's bandwidth on demand.

[0019] the invention provides the numerous advantages that are better than current system and mechanism, example comprises following aspect.

[0020] one aspect of the present invention is for stream keeps suitable allocated bandwidth, effectively utilizes whole bandwidth simultaneously.

[0021] another aspect of the present invention is to keep the priority channel bandwidth, and prevents that reserved bandwidth from being taken by the low priority asynchronous communication.

[0022] another aspect of the present invention is to provide autonomous network control with non-centralized system, and it is crack manager or moderator when not required.

[0023] another aspect of the present invention is to provide appropriate transition in new connection or after disconnecting connection, does not wherein need complete bus reset, does not also need to hinder existing communication.

[0024] another aspect of the present invention provides network service, and therein, to network interpolation or removal device the time, QoS is guaranteed, and important audio does not need to be interrupted.

[0025] another aspect of the present invention provides a kind of being used for and is waiting step stream and the non-flexible and extendible mechanism that waits shared network bandwidth between the step stream, and can be simply and realization at low cost.

[0026] another aspect of the present invention provides the audio/video flow transmission by time slot, wherein can obtain continuous slot so that support high rate stream.

[0027] another aspect of the present invention provides the audio/video flow transmission, and wherein the internal clocking difference between the transmitting device on the network can not accumulated.

[0028] another aspect of the present invention provides the audio/video flow transmission, wherein in each cycle, add predetermined or the optional time interbody spacer so that the carrying asynchronous transmission, thereby guarantee quick asynchronous transmission.

[0029] another aspect of the present invention provides the audio/video flow transmission, wherein flows transmitter and the stream receiver was checked time slot before flow transmission begins, thereby avoids possible time slot to use conflict.

[0030] another aspect of the present invention provides the audio/video flow transmission, wherein, if first transmitter and receiver that is used to set up low error rate communications pair and second transmitter and receiver between exist fully and decay, then first transmitter and receiver is to utilizing the one or more time slots of second transmitter and receiver to using.

[0031] another aspect of the present invention provides the audio/video flow transmission, and wherein, the time slot allocation process is with to leave over CDMA/CA (carrier sense multiple access/anticollision) device compatible.

[0032] another aspect of the present invention provides the audio/video flow transmission, wherein, obtains time slot by autonomous arbitration, and does not need special-purpose moderator.

[0033] another aspect of the present invention provides the audio/video flow transmission, wherein, distributes time slot with flexi mode, and redistributes request mechanism and allow existing apparatus to make full use of bandwidth.

[0034] another aspect of the present invention is to produce the pseudo-data of not using time slot that are used to fill in the reserved bandwidth part (time domain or frequency domain), loses so that prevent time slot.

[0035] another aspect of the present invention is the bandwidth usage that allows to distinguish order of priority, simultaneously the back compatible of the asynchronous device of maintenance and non-differentiation order of priority.

[0036] another aspect of the present invention allows the segmentation priority in transmission, makes transmission priority share liberally between stream.

[0037] another aspect of the present invention is the use of the order of each active flow than the low order priority value, wherein, more reasonably obtains time slot by the virtual net in server or the physical network.

[0038] but another aspect of the present invention is by quality, integrality or fail safe at automatic enhanced flow of protection bandwidth time spent, improve effective utilization of bandwidth.

[0039] another aspect of the present invention is to reduce for stream provides auto-bandwidth when the quantity of worsening condition or transmission request increases.

[0040] others of the present invention will this explanation to announce the lower part, wherein, detailed description is not to its restriction for full disclosure the preferred embodiments of the present invention.

The summary of some views of accompanying drawing

[0041], will more fully understand the present invention by with reference to the following accompanying drawing that illustrates of only being used to:

[0042] Fig. 1 is the block diagram that is expressed as the dwelling house power line communication network with the server that distributes and client computer on the virtual PLC network.

[0043] Fig. 2 is the block diagram of the ready server of PLC according to an aspect of the present invention, is expressed as to have PLC interface, content storage devices, display, user interface and RCI.

[0044] Fig. 3 is the block diagram of PLC interface according to an aspect of the present invention, and the coded communication from server-bus to the PLC network is described.

[0045] Fig. 4 is the block diagram of client apparatus according to an aspect of the present invention, illustrates that configuration is used for the client computer TV of the connection on the PLC network.

[0046] Fig. 5 is the sequential chart of Network Transmission according to an aspect of the present invention, illustrates that one of the transmitter installation of serving as cycle main controller role produces the cycle initial signal.

[0047] Fig. 6 is the sequential chart of Network Transmission according to an aspect of the present invention, and transmission cycle T is described _cThe arbitration period of interior initial time slot.

[0048] Fig. 7 is the sequential chart of Network Transmission according to an aspect of the present invention, and first server that transmits stream at the time slot that obtains from arbitration is described.

[0049] Fig. 8-the 9th, the sequential chart of Network Transmission according to an aspect of the present invention illustrates the new transport stream that begins after the transmission of beginning stream shown in Figure 7.

[0050] Figure 10 is the sequential chart of Network Transmission according to an aspect of the present invention, and the time slot availability that response flow finishes is described.

[0051] Figure 11 is the sequential chart of Network Transmission according to an aspect of the present invention, is illustrated as the part in each cycle of asynchronous communication reservation.

[0052] Figure 12 be according to an aspect of the present invention, the sequential chart of the arbitration time period in Network Transmission, the relative timing to the request of time slot as the function of flow priority is described.

[0053] Figure 13-the 15th, the sequential chart of Network Transmission according to an aspect of the present invention illustrates that the time slot that is undertaken by the stream transmitter reduces to allow to transmit new stream.

[0054] Figure 16 is the sequential chart of Network Transmission according to an aspect of the present invention, illustrates that the puppet transmission of being inserted by the cycle main controller is so that reserved time slot uses for waiting to go on foot.

[0055] Figure 17 is the sequential chart of Network Transmission according to an aspect of the present invention, but illustrate the cycle main controller in the asynchronous period of reservation in each cycle not more available time slot but time slot this cycle etc. the step partly in the time spent discharge pseudo-time slot and use for asynchronous communication.

[0056] Figure 18-the 19th, the sequential chart of Network Transmission according to an aspect of the present invention illustrates that first and second streams obtain additional time slot so that increase quality, integrality or the fail safe of flow transmission.

[0057] Figure 20-the 21st, the sequential chart of Network Transmission according to an aspect of the present invention illustrates that time slot reduces to be performed so that allow the new transmission of beginning.

The detailed description of invention

[0058] more specifically with reference to accompanying drawing, for illustrative purposes, the present invention realizes with the equipment of the general expression of Fig. 1 to Figure 21.Be appreciated that this equipment can change on configuration and details at part, and this method can change on particular step and order, and not deviate from basic conception disclosed herein.

[0059] 1. power line network.

[0060] allocated bandwidth as herein described and reservation technology can be used for many networks of different type, and the utmost point is suitable for power line communication (PLC) network.As an example, the theoretical foundation of this paper making in power line communication network is used for describing the present invention.But, all or part of other latticed form that is applicable to of these theories, for example wireless network and other network.

[0061] 1.1 network configuration.

[0062] Fig. 1 illustrates the example 10 of the distributed system of working on dwelling house PLC network.Residence 12 is expressed as the AC power line 14 with a plurality of rooms of interconnection.The distributed system that comprises server-1 16, server-2 18, client computer-1 20 and client computer-2 22 is connected to power line by having the AC socket that does not use socket 24 that illustrates as an example usually.For the sake of brevity, AC power line 14 connects not shown to the outside of distribution transformer etc.

[0063] cable 26 is expressed as and is connected to server-1 16, so that provide the visit such as the various contents of cable programming, the Internet connectivity or the like.Everybody will appreciate that, includes linear formula and wireless and can be received by system in the connectedness of other interior form.

[0064] server in this example-1 16 configuration is used for storing audio/video data, and can the one or more client computer on the PLC network send stream.From cable 26, the audio/video content stream that receives by server-1 16 can send client computer to, as client computer-1 20 or client computer-2 22, and send other server to.Server in this example-1 16 and server-2 18 are with the similar functional work of carrying out.Term as used herein " stream " expression waits step and asynchronous communication stream.

[0065] 1.2 server.

[0066] Fig. 2 illustrates an example embodiment of server-1 16.The RF signal that tuner front end 30 receives from cable system 26, it is by 34 pairs of codec block 32 decodings of decoding from the restituted signal of tuner front end 30 of combined memory.Decoded video signal for example is converted to analog signal by D/A converter 36, and shows on display 38.Decoded audio signal is converted to analog signal in D/A converter 40, amplify in amplifier 42, sends to audio-frequency transducer (being loudspeaker assembly) 44 then.For recorded video stream, codec 32 this stream send to data storage subsystem, as hard disk drive 46 (HDD), it should visit by the interface 48 that is connected to bus 50.When playback of recorded flows, the stream that codec 32 receives from HDD 46, and to its decoding.

[0067] considers that server-1 16 sends the situation of video flowing to client computer-120 by power line 14.Stream from tuner front end 30 sends to PLC interface 52 by codec 32, and sends to the PLC network by AC connection 54, so that received by client computer-1 20.Similarly, in order to play the stream of record, send to PLC interface 52 by the PLC network, receive for client computer-1 20 from the stream of HDD 46.

[0068] PLC interface 52 preferably includes encryption and decryption mechanism.General preferable methods is that all communications process before sending by the PLC network is encrypted, and deciphers after reception.

[0069] user can be connected to the keypad 56 of bus 50 or come control operation via the remote control unit 60 that remote interface 62 is connected to bus 50 by using via keypad interface 58.By bus 50 is that CPU 64 receives order, the instruction in CPU 64 run memories 66.Modulator-demodulator 68 connects for server provides network, and is expressed as an example and external network is connected (being phone, DSL, cable, LAN, WAN etc.) and be bridged to the addressable bus 50 of circuit element in the server 16.

[0070] Fig. 3 illustrates the block diagram of PLC interface 52.In the example shown, OFDM (OFDM) technology is used for the signal transmission by power line.The data that transmit receive from bus 50 by bus interface 70, and can be stored in where necessary in the buffer storage 72.Error correcting code is added to data in forward error correction coder (FECE) 74, its result is interweaved by interleaver 76, and is being converted to parallel data by modulator 80 modulation and before sending to invert fast fourier transformation (IFFT) piece 82 by serial-to-parallel transducer 78.In IFFT82, carrier wave is assigned to each input signal, and signal is through invert fast fourier transformation.Gained signal from processing block 74-82 then is sent to AFE (analog front end) (AFE) 84, sends to PLC 14 by attaching plug 54 then.

[0071] the piece explanation Data Receiving of representing in the latter half of Fig. 3.The data flow that AFE 84 receives from client computer by the AC connector 54 that is coupled to PLC 14 (Fig. 1).Receive data and carry out fast fourier transform, carry out demodulation, and carry out the parallel-to-serial conversion by P-S transducer 90 by demodulator 88 by FFT 86.The gained signal is deinterleaved by deinterleaver 92, by 94 error correction of fec decoder device, sends to bus interface 70 then.

[0072] operation of the piece shown in controller 96 control charts, monitoring network, and produce signaling, for example transmit cycle initial signal and arbitration request signal.

[0073] 1.3 client computer.

[0074] Fig. 4 illustrates an example embodiment of client computer, for example client computer-120.Under the control of CPU 102 combined memories 104, the interconnect circuit of client computer 20 of local bus 100.Power line communication (PLC) network interface (IF) 106 receives from another device, as the stream of server-116 (Fig. 1) or server-218 by power connector 108, and it is sent to decoder 110 in conjunction with local bus 100.

[0075] should be appreciated that PLC interface 106 can realize according to same way as shown in Figure 3, perhaps adopt any alternative circuit design easily to realize.Decoder 110 combined memories 112 carry out work, so that the convection current decoding.Decoded video signal for example by D/A converter 114 be converted to correct format, for example from the digital to analogy form, and on display unit 116, show.The audio signal that produces from decoder 110 is converted to for example analog signal for audio frequency output by D/A converter 118, and is amplified by amplifier 120 before outputing to audio-frequency transducer 122.

[0076] plc communication should process be encrypted before sending to power line, and in deciphering after power line receives.The order of client computer 20 can adopt the keypad 124 that combines with keypad interface 126 or by utilizing the remote control unit 128 that combines with remote interface 130 to import, wherein, order is received by local bus 100 by CPU 102.

[0077] 2. autonomous network control.

[0078] realize that IEEE 1394 networks need the time slot manager, still, the present networks communication aspects does not need to utilize this manager, because each device on the network should have identical functions, just those devices are counted as " leaving over " device.

[0079] the hoc network ruton is crossed following operation and is controlled: (a) do not detect the cycle at first device of for example wishing to transmit stream and produce the cycle initial signal during initial signal on network; (b) to the time slot arbitration, independently carry out, be used for delivering to the destination spreading so that obtain enough time slots by each transmitter; And (c) adopt resulting time slot to transmit and flow.

[0080] time slot obtains in arbitrated procedure.In order to obtain time slot, the device monitoring network and the request that sends are to obtain available time slot.After obtaining time slot, it begins transmission.It and which device forward who to send the device operation of what data irrelevant, whether device only detects each time slot occupied.As the result of decentralized network control, any disconnected connections in the device and need not to execute full weight and put, thus the permission user connects or disconnecting apparatus in the mode that is similar to Ethernet device.

The generation of [0081] 2.1 cycle initial signal.

[0082] Fig. 5 explanation server-1 16 beginning therein transmits the Network Transmission 150 under the situation that waits step stream to client computer 20.At first, server-1 16 monitoring PLC Network Transmission 150 is so that communicate.If do not detect communication, then server-1 16 becomes initial main controller of cycle, and begins regular transmission cycle initial signal 152 (period=T _c).

[0083] if detect signal conflict or another signal, server-1 16 dwelling period initial signal immediately then, and, will attempt again this cycle after the time at certain rollback.During rollback, transmitter monitoring periods initial signal, and only when not detecting any signal, just attempt again producing.The rollback time is the interior random time value of scheduled time value scope preferably.If another device is transmitting the cycle initial signal, then server 16 does not produce the cycle initial signal, because only allow a device on the network as initial main controller of cycle.

[0084] should be appreciated that in this method, with T cycle time _cRepeat visit to power line communication (PLC) network.Framing in cycle time, each time slot has regular time length.In some applications, it is significant making this cycle timing and the 60Hz cycle synchronisation of power line.

[0085] 2.2 first transmission.

[0086] Fig. 6 illustrates the arbitration that occurs when the time slot in the device trial acquisition PLC Network Transmission 150.Server-1 16 obtains to be used to send the time slot of the regular length of stream.According to the priority of bandwidth and data, transmitter can obtain one or more continuous slots.In order to obtain time slot, server-1 16 adds the input time slot arbitrated procedure.Arbitrate best set time generation with relative each cycle, for example the T1 after cycle initial signal 152 begins and the time period of sustained periods of time T2.Server 16 is the sending time slots request signal in this arbitration period.If server-1 16 wins arbitration, then begin transmission after the signal 152 in cycle time.If not, then server-1 16 allows the side of winning to begin to transmit, and will attempt obtaining another time slot subsequently.

[0087] Fig. 7 illustrates that server-1 16 therein wins the transmission situation of one or more time slots just available after cycle initial signal 152.Frame 154 is represented cycle hereto and the time slot that obtains for subsequent cycle.In case obtain, device in addition can't interrupt time slot.Utilize these periodically time slots, server-1 16 transmits stream.Should be noted that life period gap between cycle initial signal 152 and time slot 154.This gap preferably is set to absorb valuably the finite duration of transmission delay.But for the sake of clarity, the relative period T of accompanying drawing _cAmplified the size of time slot and time slot.Should be appreciated that each period T _cCan be divided into hundreds of time slots.Slot length and time slot length is fixing duration preferably, thereby whether allow device to detect time slot easily occupied.

[0088] 2.3 second stream.

[0089] Fig. 8 and Fig. 9 explanation is by the beginning of other transmission of PLC network.In this case, server-2 18 begins another transmission such as step such as grade to client computer-2 22.Server-2 18 sense cycle initial signal 152 is also synchronous with it, as shown in Figure 8.Because its monitoring PLC network, therefore, server-218 detects time slot 154 and is using, thereby it will attempt obtaining time slot 154 time slot afterwards.The new arbitration T3 of period after cycle initial signal 152 begins, and its length preferably arbitration period T2 with other is identical.Time period T3 is easy to add that from the length of time slot 154 the time slot sum obtains.The gap is preferably between the cycle initial signal and first time slot or forms between time slot between hour, so that absorb the transmission delay on the power line.

[0090] server-218 transmits request signal in arbitration period T2.If server-2 18 wins this time slot, then new time slot is right after time slot 154.The time slot piece 156 that Fig. 9 explanation is won by server-2 18 in this case.Server-2 18 adopts this time slot that newly obtains to send new stream to client computer-2 22.

[0091] everybody will appreciate that, the internal clocking of each device on the network is slightly different with other device, and still, because crystal-controlled character and related high workload frequency, these differences should be in the scope of a few millionths usually.Being accumulated in many traditional digital transmission systems of clock mistake difference is a problem.But this problem does not occur in native system, because each device Measuring Time span from initial main controller of cycle is produced cycle time initial signal, clocking error is not wherein accumulated.

[0092] 2.4 scatters time slot.

[0093] Figure 10 illustrates an example of the time slot availability of the end that responds some time slots.Should be appreciated that device can obtain that time slot when winning the arbitrated procedure of any available time slot.

[0094] for example, if transmitter is just attempting obtaining time slot 154 one or more time slots afterwards, then its transmits request in the arbitration period T2 after the period T3 of initial 152 beginnings of cycle.If transmitter wishes to obtain time slot 158 time slot afterwards, then in the period T2 after the period T4 of initial 152 beginnings of cycle, send request.When transmitter requires the plurality of continuous time slot so that when sending high bit-rate streams, transmitter monitoring PLC Network Transmission, and select a series of available time slot.This mechanism promotes that continuous slot is used for single high bit-rate streams, scatters those time slots of distributing to data flow and hinder on time shaft.But if network is just busy, then transmitter can obtain to scatter time slot.The present invention preferably allows to be chosen in hope and transmits data immediately and wish to use the mode of trading off between the continuous slot.

[0095] 2.5 asynchronous transmission period.

[0096] has manyly when not using time slot when the PLC network, carry out the step transmission such as asynchronous transmission can be described in the trifle of front.A difference is, asynchronous transmission can utilize identical time slot in the maximum of n consecutive periods just in use in all available asynchronous time slot.If extra slots can be used, then asynchronous transmission can continue to utilize n the time slot outside the continuous slot.

[0097] if time slot is unavailable, then after n cycle, asynchronous transmitter must discharge time slot, and sacrificial vessel has other transmission of higher priority to use.If there is not this class transmission just waiting for the PLC visit, then transmitter can obtain identical time slot once more.The value of the maximum quantity of consecutive periods n can respond the priority of asynchronous transmission and select.For example, n can comprise the little value of low priority transmission and the higher value of higher priority transmission.

[0098] when all time slots by etc. step transmission when taking, the time period that may require asynchronous transmission to wait for to prolong is to obtain available time slot.For fear of possible adverse condition, preferable methods is, the part in each cycle is assigned to asynchronous transmission and uses, and wherein, the task of relying on asynchronous transmission is for want of data and scarcity not.

[0099] Figure 11 as an example description time section 160 as the use of asynchronous transmission period.This period, the time T S after cycle initial signal 152 began, and finished immediately before the beginning of next cycle initial signal.In the asynchronous transmission period 160, asynchronous transmitter preferably generally with wait the step to transmit identical mode to obtain time slot.As an alternative of this mechanism, according to traditional CSMA/CA basis, transmitter can obtain the time slot access rights in the period 160.

[00100] the asynchronous transmission period is useful for many application, because its guarantees for the back compatible of leaving over the PLC device that CSMA/CA function etc. only is provided.Everybody will appreciate that, current and previous PLC device (leaving over device) does not provide arbitration or waits the ability that the step transmits.Therefore, native system can allow these devices only just to carry out asynchronous transmission in for the asynchronous movable period that keeps.

[00101] 2.6 arbitration.

[00102] how this trifle explanation carries out arbitration in the present invention.As an example, suppose that all transmission ranges are divided in three kinds of priority levels.

[00103] priority 1 (the highest): example: VoIP (waiting the step)

[00104] priority 2 (medium): example: audio/video transmission (waiting the step)

[00105] priority 3 (minimum): example: data passes, world wide web access etc. (asynchronous)

[00106] should be appreciated that IP-based voice (VoIP) are to very sensitive application of stand-by period, wherein, for this example, provide limit priority to it.Second priority offers audio.Give lowest priority to data passes (file copy, world wide web access or the like).During to the time slot arbitration, the transmission with higher priority surpasses the transmission of lower priority.

[00107] Figure 12 illustrates time slot request timing 170.As mentioned above, wish that the transmitter that wins time slot sends request signal in the arbitration period, it regularly depends on the priority of the stream that will send.For highest priority stream, transmitter sends request in the beginning part 172 of arbitration period T2.If stream has the priority of next grade, then request should send after highest priority request, and the rest may be inferred.At last, the lowest priority request sends in the decline of arbitration period T2.Should be appreciated that though having described three time portion supports three kinds of priority,, according to theory of the present invention, can support any amount of priority.

[00108] during arbitrating, when transmitter wished to send the stream of second high priority, it was from beginning the monitoring arbitration period.If detect first priority request, then transmitter does not manage to obtain this or these time slot.Equally, if transmitter wishes to send low priority flows, and it detects high-grade or the middle grade priority request, and then transmitter is abandoned attempting obtaining this time slot, thereby is obedient to the higher priority transmission.

[00109] requests for arbitration preferably repeatedly sends, and for example crosses over three consecutive periods (perhaps other predetermined or selectable time interval).In the arbitration period, if certain time slot is not detected the higher priority request, then transmitter wins time slot.Win arbitration in order to ensure the higher priority request, preferable methods is, response transmission priority and use different arbitration monitoring length.Be for the example of described situation below based on the monitoring period of priority.

[00110] priority 1: 3 cycles

[00111] priority 2: 5 cycles

[00112] priority 3: 7 cycles

[00113] if transmitter sends highest priority request in three consecutive periods, and do not detect the higher priority request, then transmitter can bring into use time slot to transmit.Similarly, if transmitter sends low priority request in seven consecutive periods, and do not detect the higher priority request, then transmitter can begin transmission.

[00114] still, if two or more transmitters send the request with equal priority, then can clash.If transmitter detects conflict, then rollback from the request channel for example enters the random back pattern.In the random back pattern, after the randomized stand-by period, transmitter sending time slots request once more.

The exchange of [00115] 2.7 gap information.

[00116] everybody will appreciate that, responds some PLC network condition, and the serious signal attenuation on the network may stop one or more devices to detect the time slot that has used.For example, transmitter may detect time slot and " it seems " and be not used, and in fact just is used but remote receiver may detect same time slot.For fear of this fault, preferably carry out duplication check, wherein, after winning available time slot, whether transmitter is available from the viewpoint of measures time slot of receiver to the receiver inquiry.If it seems that from two ends time slot all is available, then transmitter begins transmission.If it seems that from receiver side time slot is unavailable, then transmitter is abandoned this time slot, and monitors another available time slot, so that avoid time slot collision.

[00117] another advantage of this mechanism is, each node can respond at development length or diminish the decay on the PLC network and effectively utilize local available time slot.Like this, local service can be on the time slot of the remote portion that also is being used for network transport service.End-to-end examination to operating position is avoided a conflict, and also for the time slot that uses positive route traffic carrying capacity in another part of network simultaneously offers an opportunity, this separates by abundant decay, so that prevent excessive data error simultaneously.

[00118] example of " using again " as this time slot considers that wherein server-116 and client computer-1 20 are arranged on the situation of physical location contiguous on the PLC network 14.In addition, consideration is at the another part that is not the network of close server-1 16 and client computer-1 20, the relative part in the family for example, perhaps more preferably at shared identical distribution transformer, do not have blocking filter or do not eliminating at least in the different home of blocking filter in full force and effect aspect the inter-household signal seepage, server-2 18 and client computer-2 22 is close mutually.Therefore, supposition in this case, first and second client-server between have obviously decay.Under these conditions, everybody will appreciate that two pairs can be used same time slot or crossover time slot simultaneously, have wherein exempted disadvantageous transmission collision relatively.

[00119] AFE 84 in the server-1 16 can comprise the Adaptive Transmission control function of power as required.When client computer nearby, and the signal attenuation between them is when little, server-1 16 reduces through-put power.When client computer a long way off or signal conditioning bad, and when having big decay, server-1 16 obtains through-put power.This mechanism is used for power consumption and electromagnetic interference at first.But it also helps to use a long way off same time slot.

The initial recovery of [00120] 2.8 cycle.

[00121] consider wherein server-1 16 be produce the device of the cycle initial signal 152 that is used for the PLC network and other device with its operation and the synchronous situation of this cycle initial signal.When server-1 16 disconnects connection, the cycle initial signal will be interrupted.

[00122] the present invention adapts to the use on the dynamic network, because in case the cycle initial signal is lost, another device will be taken over as the cycle main controller, and begin to send new cycle initial signal immediately, and will be general preferably after the timing of primitive period main controller.A kind of pattern of the present invention allows cycle main controller response cycle main controller to disconnect to connect and pre-determines its succession's order.

Notice that [00123] each device moves a moment under the condition that does not have the cycle initial signal, because internal clocking locks onto the primitive period regularly.At last, clocking error will be accumulated and losing lock.Before losing lock, another device will begin to send the cycle initial signal.

[00124] the present invention prevents that two or more devices from all becoming the cycle main controller.Be used to prevent that a kind of mechanism of a plurality of main controllers from being by using fallback mechanism, wherein, when running into contention, the cycle main controller rollback of expection is delayed time arbitrarily, therein, the cycle that the becomes main controller that at first returns (no matter whether needing, two or more back-off period) scope is separated to single main controller as the cycle main controller.Everybody will appreciate that, all devices preferably adopt its own timing cycle to carry out work, till recovering initial signal, can prevent to have now interruptions in transmissions therein.

The time slot of [00125] 2.9 new stream is redistributed.

[00126] for more robust transmission or higher-quality transmission (being the picture transmission) are provided, if enough bandwidth can be used, then audio can adopt than the more time slot of minimum essential requirement.Everybody will appreciate that do not have intrinsic transmission advantage not produce from the maintenance time slot uses.Consider to duplicate the simplified example of transmission, wherein, one or more streams are replicated not using on the time slot, thereby improve the integrality of data.Equally, additional time slot quality, integrality or the fail safe that can be used to improve the one or more streams that transmitted according to any convenient manner.Another example is the situation of variable bit rate stream, wherein, when transmitting with higher transmission rates, provides the image of better quality.Because many such technology are known in the art, therefore need be about the more details of these methods.Therefore, a kind of pattern of the present invention allows fluently to use except being all available time slot asynchronous data kept, so that improve quality, integrality or fail safe.

[00127] is used and new stream will be sent out the time when all time slots, may needs to carry out time slot and redistribute.As an example, the transmitter of new stream can at first send the request that requires other device to discharge time slot in the asynchronous transmission period, and wherein, each transmitter that receives this request can discharge a part of time slot that it is just using.The transmitter monitoring PLC network of new stream, and check the time slot that these are available recently.If it is available that enough time slots become, then transmitter obtains time slot, and transmits stream.But available if not enough time slot becomes, then transmitter sends another request.

[00128] everybody will appreciate that, these time slot requests can comprise precedence information, and wherein, stream lower or equal priority is forced to the time slot of the higher percentage that the release ratio higher priority flows discharged.In addition, according to the increase progressively advantage of stream to those time slots formation, the release of time slot also may take place.In either case, time slot is discharged after one takes turns or take turns more request by dispensing device, thereby satisfies the demand of new transmitter at least in the scope that the relative priority level of new stream is stipulated.

[00129] Figure 13, Figure 14 and Figure 15 explanation reduces time slot at the existing stream of request at first and uses, begins after obtaining enough time slots for new stream then the exemplary sequence that newly flows.

[00130] in Figure 13, step streams 154,156 such as two are expressed as and take available time slot (being expressed as two order time slot pieces), certainly except that the asynchronous transmission period 160.The consideration transmitter wishes to send the new situation that waits step stream.At first, new transmitter can be redistributed request to existing transmitter sending time slots.This request can be broadcasted.Which device new transmitter needn't understand is existing transmitter.Existing transmitter receives this request, and reduces its time slot use amount, and changes encoding rate as requested to adapt to the bandwidth that reduces.

[00131] Figure 14 explanation is owing to the time slot of the request that responds the transmitter of making a fresh start is redistributed the additional time slot of opening.

[00132] Figure 15 explanation is won the arbitration of available recently time slot and is begun to send the example of the new transmitter of new stream 162, generally includes a plurality of order time slots.In new stream is situation from the transmitter identical with existing stream, for the existing stream that transmitter is just sending, the suitable inter-process of the request of redistributing.

[00133] 3. waits pseudo-transmission of step.

[00134] should be known in that leaving over the PLC network equipment is restricted to only CSMA/CA function usually.Therefore, exist them can begin the possibility of transmitting at any time.The asynchronous transmitter that the present invention allows for example to leave on the device is at first checked the asynchronous transmission period 160.If time slot is available in the transmission period 160, then transmitter uses those time slots.Prevent that at first, preferably period TS is subjected to asynchronous access.

[00135] Figure 16 explanation prevents to wait the step to flow and is left over an example of asynchronous flow interruption.In this diagram, pseudo-data are expressed as for time slot 164a-164d and produce, and allow the asynchronous transmission period 160 use for leaving over device simultaneously.For to not using time slot that protection is provided, those in the asynchronous transmission period 160, cycle main controller all in period TS are not used and are transmitted pseudo-data in the time slot, thereby prevent to use at first by leaving over device.The composite crossover period T5 of real data time slot and pseudo-data slot, thus prevent from T5, to begin asynchronous access.Everybody will appreciate that accompanying drawing is reduced to only represents four possible time slots, still, and at period in cycle T _cIn hundreds of time slots can be provided.The priority of pseudo-transmission is lower than other and anyly waits the step transmission, thus step transmitters such as permission obtain pseudo-time slot immediately and begin new wait to go on foot flow.

[00136] Figure 17 illustrates that time slot is provided the compliance of time slot when unavailable to asynchronous transmitter by the cycle main controller in the asynchronous transmission period 160.If asynchronous transmission zone 160 is taken fully, then the cycle main controller discharges at least a portion of pseudo-time slot, uses for new asynchronous transmission.Represent among the figure that pseudo-transmission 164c, 164d are dropped, wherein new asynchronous transmitter has been brought into use time slot 166, and it can be a new part that flows or related with the data of transmission in the period 160.This mechanism guarantees effectively work when a large amount of institutes requested service amount is made up of asynchronous access.Notice that the periodicity that offers asynchronous transmission is restricted.After end cycle,, then wait the step transmission can use same time slot if another time slot is unavailable.

[00137] 4. based on the arbitration of virtual net.

[00138] in the house market of PLC network, typically situation is, the shared distribution transformer of some dwelling houses, thereby impel a plurality of virtual nets on single one physical PLC network, to work (exception when utilizing effective blocking filter, occurring).In order to prevent to communicate by letter monitored or utilized by other virtual net on the single physical network, utmost point preferable methods is, all communication processes by network are encrypted, and for example adopt public-key encryption, wherein have only the shared public keys of device ability in the single family.

[00139] adopt public-key encryption or similar encryption technology, neighbours can't be to the transmission data decryption when not having key, and each family sets up its oneself VPN (Virtual Private Network).Under this many crossovers network environment, go wrong, because do not exist the network main controller to control the utilization of traffic carrying capacity and shared bandwidth.Because the visit by network is carried out according to handling earlier first, therefore, even one family does not take the whole of powerline bandwidth, also may take the major part of powerline bandwidth.When the device among the neighbour's can't be brought back network that the justice that for example constitutes bandwidth shares a part of, unjust phenomenon appearred.

[00140] server increases progressively the active flow numbering for each stream of given priority level provides.The server that transmits three streams will embed numeral 0,1,2 in these streams, if there is priority this time, then preferably carry out according to priority.Should be appreciated that any method that can adopt marked flows, the relation during for example numbering, text, change are flowed between the element etc.As an example rather than restriction, server this first-class mark " 0 " to being sent, to second flow label " 1 " that is sent, and the 3rd flow label " 2 " to being sent, the rest may be inferred.The first-class highest priority stream that is generally that is sent.

[00141] when having two stream contention slots of equal priority, the stream with less numbering wins this time slot.Two streams produce from different transmitters, preferably in different virtual nets.This time priority contention mechanism makes server obtain the ability equalization of the time slot on the PLC network.On busy network, this can be exchanged into the first-class time slot that wins that server transmits, and the second or the 3rd stream then unlikely obtains time slot.This mechanism prevents that the server from transmitting a plurality of streams and partially or completely monopolizing powerline bandwidth.

[00142] the active flow numbering is updated when each stream finishes, thereby allows suitably competition in all the other transmission of server.For example, the highest priority stream in given priority level (promptly waiting the scope that goes on foot the priority between asynchronous), when promptly stream " 0 " finishes, other stream is renumberd, so that available recently " 0 " inferior priority of utilization best.Therefore, when first-class end, the second and the 3rd flow point is not marked as active flow numbering " 0 " and " 1 ".

[00143] or, do not renumber, but can provide new numbering to new stream according to the sum of active flow.Because time priority with " 0 " beginning, therefore, provides than the numbering that flows sum little 1 new stream.For example, three streams are movable, give 0,1 and 2 to each respectively.After the first-class end with numbering " 0 ", new stream will be obtained time priority " 2 ".Two or more flow shared identical inferior priority and do not have problems, because inferior priority is used for obtaining time slot.

[00144] should be appreciated that two or more servers can connect in given virtual net.In the situation of a plurality of servers on virtual net, active flow numbering can be shared in given virtual net, makes server cooperation rather than competition in the network.For example, the programmed configurations of server becomes to allow the server exchange active flow table in the same virtual net, and selects the ordering of stream jointly and adopt new active flow to number mark newly to flow.

[00145] 5. redundant transmission.

[00146] as mentioned above, when time slot can be used, transmitter can use and exceed the extra slots that comprises outside those required time slots of stream, effectively utilizes the bandwidth of waste originally there.By the use of additional time slot, transmitter can improve the audio/video encoding rate, so that provide higher-quality video to show and/or audio frequency output.In addition, transmission can be adopted more healthy and stronger modulation technique, for example is transformed into 16-QAM or QPSK (Quadrature Phase Shift Keying) from 64-QAM (quadrature amplitude modulation).Everybody will appreciate that, adopts more healthy and stronger modulation technique can reduce the electric and fragility radio noise source.As previously described, the reproducible all or part of flow data of transmitter (that is, but sending) in the redundancy of the stream of double time slot time spent, when utilizing additional time slot in conjunction with error correction or more healthy and stronger error correction.

[00147] Figure 18 and Figure 19 explanation obtains extra slots for flow transmission.In Figure 18, time slot 154 is assigned to first-class, and time slot 156 is assigned to second stream.For simplicity and for the purpose of clear, other case description in this example and this explanation use of single time slot, still, be to be understood that, in fact it may be available reaching hundreds of time slots, and according to the data transfer rate that flows, for can taking a plurality of time slots for constant current.In addition,, also can use the segmentation of other form, for example based on segmentation of frequency etc. though described time slot.

[00148] situation of consideration Figure 18 is noted that the major part of bandwidth is not used, as period T _cPart shown in, do not send flow data therein.In this case, available time slot can be used by the transmitter of each stream.The present invention is configured to prevent that the stream from obtaining the unfair part of available time slot, a kind of mechanism that is used to achieve this end allows each stream for example to obtain one by one not use time slot in some time interval, for example allows each transmitter to obtain a time slot at per 300 milliseconds.This mechanism provides the chance that obtains time slot for each stream liberally.The priority of obtaining these extra slots is lower than the priority that all wait the step transport stream, and wherein, the time slot that new stream is obeyed in these requests inherently obtains.

[00149] example of the process of extra slots is obtained in Figure 19 explanation.The transmitter that transmits on time slot 154 obtains time slot 154 ', and the transmitter related with time slot 156 obtains extra slots 156 '.

[00150] is used to transmit pseudo-data so that one aspect of the present invention of step time slots such as reservation is described to prevent that equity from going on foot the mechanism of the asynchronous access in zone.Other use that should be known in redundant transmission or extra slots is used for keeping those time slots, increases flow transmission benefit (being quality, integrality, fail safe or its combination) simultaneously.In this case, the cycle main controller needn't produce pseudo-transmission, but requires transmitter to obtain extra slots and change streaming mode so that utilize extra slots, and abandons these extra slots when new stream is attempted obtaining time slot.

[00151] consideration has the situation of the transmitter of the new stream that will send, and wherein, its monitoring network is also searched available time slot.If do not find available enough time slots, then transmitter produces asynchronous command to all devices on the network, and ask them to stop or reducing their uses at least extra slots, for example be used for redundant transmission or otherwise be used to improve the quality, integrality or fail safe.When receiving this request, other transmitter can discharge all or part of of its extra slots.This request may be to any devices broadcasting.New transmitter needn't be known all existing transmitter.

[00152] as an example, can require other transmitter to abandon and only adopt original time slot, at least till new stream has obtained its required time slot the use of all extra slots.For example, when extra slots was used for higher rate the audio/video stream encryption, transmitter reset to the original coding rate to encoder before discharging redundant time slot.Similarly, the technology that is used for improving modulation technique or safety measure is reconfigured to raw mode, and extra slots is released.Should be noted that under the control of each transmitter and carry out redundant transmission, and need not the intervention of master control set with non-centralized system.In this, everybody will appreciate that this redundant transmission can be applicable to the centralized network system, and is not limited to decentralized network.

[00153] 6. the time slot of response busy network situation reduces.

[00154] on busy network, also certain situation may occur, therein, do not wait the step time slot to use, but transmitter given back the employed any extra slots that for example is used for redundant transmission.In this case, the present invention is configured to reduce basic flow transmission speed, so that allow to transmit new stream.

[00155] Figure 20 and Figure 21 explanation reduces to flow bandwidth so that an example that allows other new stream to transmit during network flow transmission 150.Four streams 180,182,184,186 that Figure 20 explanation just is being transmitted, wherein each stream has obtained the time slot of equal amount basically.Also supposition in addition, the T in this example _cBe divided at least ten to 100 time slots, it provides enough little granularity that the ability that changes the number of timeslots that is used for given flow transmission is described.

[00156] because enough time slot is unavailable, therefore, the transmitter of new stream sends asynchronous command to all devices, requires the number of timeslots that their reduce them and just using.Order preferably comprises the degree of expression request and/or one or more parameters of priority.For example, request can comprise target time slot and reduces target rate, for example 80%.Receiving this when order that each transmitter is by the part of the time slot that discharges it and obtained, reducing the audio/video encoding rate, for example be reduced to 80% of original coding rate.

[00157] the present invention is configured as transmitter alternatively and provides certain flexibility ratio when reducing to target rate in that time slot is used, and wherein, has lower priority stream or more may reduce the transmitter that bandwidth uses and at first abandon time slot.Therefore, the process that acquisition is used for the time slot of new stream can comprise iterative process, utilizes available bandwidth up to most effectively.A kind of mode of thinking deeply this process is, the transmitter of attempting the acquisition time slot can require time slot to begin by the form " moderately " with request, if and its needs satisfy, it is then transferred to the time slot that requires other transmitter (the particularly transmitter of lower priority) to reduce them and makes and be used for satisfying its demand.

[00158] Figure 21 illustrates that the transmitter that sends stream 180,182,182,186 has reduced each and flowed employed number of timeslots situation afterwards.New stream obtains and discharges the part or all of of time slot.Do not require that discharging time slot is continuous slot, still, the time slot that the present invention preferably is provided in the convection current is recombinated to reduce one or more mechanism of fragment.For example, by having measured from existing time slot end rather than the time since the cycle begins, the time slot that discharges between the stream can make up, to have less fragment.

[00159] new stream wins the time slot of new release, and to mate it to the reduction ratio of the request of other channel, for example with 80% its own transmission (as much as possible) is encoded.If can't obtain enough time slots for new stream, then transmitter can send and may comprise second target rate, for example another order of 60%.

[00160] as mentioned above, in some cases, abandon the request or the order of time slot and need not flow transmitter and observe by each.As an example, time-critical and communication that do not need a kind of form of big bandwidth is based on the voice (VoIP) of Internet Protocol, and wherein the transmitter of this stream can be ignored this request or order.Reducing ratio can revise based on a plurality of factors and/or to its response, for example based on flow priority.For example, the stream of high priority is subjected to less speed reduction only.

[00161] when existing stream finishes and discharges related time slot, other stream obtains these time slots, and wherein encoding rate turns back to 100% (original value).If it is available that additional time slot becomes, then each stream can obtain that extra slots is used to improve the quality, integrality and/or fail safe, for example carry out aforesaid redundant transmission.The time slot minimizing that should be appreciated that this form is carried out under the control of each transmitter, and is not centralized, because there is not master control set.

[00162] the 7. change of present embodiment

[00163] one embodiment of the present of invention have been described as one or more realizations of example, but should be known in that each side of the present invention can be through revising, and do not deviate from theory of the present invention.Should also be appreciated that the present invention generally can be applicable to wireless and other network, and its applicability need not to be restricted to power line communication.

[00164] though above description comprises many details, they should not be considered and limit the scope of the invention, and only provide the explanation to the part of currently preferred embodiment of the present invention.Therefore, as everybody knows, scope of the present invention comprises significantly other embodiment that can become to those skilled in the art fully, and scope of the present invention just correspondingly is limited by the appended claims, if wherein do not offer some clarification on, mentioning certain element with singulative is not to represent " unique one ", but expression " one or more ".Equivalent with function all structures of the element of the above preferred embodiment that those of ordinary skill in the art is known, chemistry is incorporated into this by reference clearly, and is intended to be contained by this claim.In addition, each problem that does not need device or method will solve at the present invention will be because it will be included in this claim.In addition, do not have element, assembly or method step to be intended to be exclusively used in public occasion in the disclosure, no matter whether element, assembly or method step offer some clarification in the claims.The element that does not have claim herein explains according to the regulation of the 6th section of 35 U.S.C.112, unless this element adopt phrase " be used for ... parts " offer some clarification on.

Claims (29)

1. one kind is transmitted the method for video and/or audio stream by distributed network between device, comprising:

On described network, produce the cycle initial signal during initial signal in the cycle that do not detect;

To the time slot arbitration, independently carry out by each transmitter, so that obtain to be used to transmit enough time slots of stream; And

Adopt described time slot to transmit stream, receive for the recipient by described network.

2. the method for claim 1 is characterized in that, is not detecting other main controller when movable in cycle, thereby the transmitter that is connected to described network and becomes the cycle main controller produces described cycle initial signal.

3. method as claimed in claim 2, it is characterized in that, after producing the cycle initial signal, if run into signal conflict or detect another signal, the described transmitter that then produces described cycle initial signal stops to produce described cycle initial signal, and only produces through just attempting again after the rollback time when the initial signal that does not detect other transmitter and produced.

4. method as claimed in claim 3 is characterized in that, the described rollback time is the random time value in the prescribed limit.

5. the method for claim 1 is characterized in that, for etc. step transmission and asynchronous communication all keep the several portions in described cycle.

6. the method for claim 1 is characterized in that, also comprises by produce pseudo-transmission in untapped time slot keeping to wait and going on foot transmission bandwidth.

7. method as claimed in claim 6 is characterized in that, described cycle main controller produces described pseudo-transmission.

8. method as claimed in claim 6 is characterized in that, described pseudo-transmission produces with lowest priority, is used to transmit new stream thereby allow easily to obtain time slot.

9. the method for claim 1 is characterized in that, described arbitration comprises:

Produce the time slot request according to described cycle initial signal;

Monitoring is for the higher priority request of described time slot; And

If do not detect the higher priority request, then obtain described time slot for using, if perhaps detect the higher priority request, rollback and ask different time slots from use then.

10. the method for claim 1 is characterized in that, to the described arbitration and carrier sense multiple access/collision prevention device compatibility of leaving over of the bandwidth that transmits data.

11. the method for claim 1 is characterized in that, also comprises by distributing the inferior priority that reduces gradually in the given priority level to segment priority in transmission to each order active flow.

12. method as claimed in claim 11 is characterized in that, described priority is used to allow to have higher priority in the given priority level during to the time slot arbitration requesting party obtains described time slot.

13. method as claimed in claim 11 is characterized in that, described time preferential grade comprises order numerical value.

14. the method for claim 1 is characterized in that, also comprises by conveyer and obtains extra slots, is used to improve quality, integrality and/or the fail safe of the stream that is transmitted.

15. the method for claim 1 is characterized in that, comprises that also the asynchronous request of the transmitter of stream reduces the number of timeslots that is used to transmit stream from preparing to transmit newly by described network in response.

16. the method for claim 1 is characterized in that, the flow transmission that the device beyond described cycle main controller sends does not respond the disconnection of described cycle main controller and is interrupted.

17. the method for claim 1 is characterized in that, described network comprises power line communication network.

18. method as claimed in claim 17 is characterized in that, and is encrypted by the communication of described power line communication network.

19. method as claimed in claim 17 is characterized in that, described cycle initial signal is synchronized to the 60Hz cycle timing of power line.

20. the method for claim 1 is characterized in that, also is included in to transmit on the described time slot to flow to allow the expection receiver of transmission check described time slot before.

21. method as claimed in claim 20 is characterized in that, if each transmitter-receiver between have fully decay, the time slot in the then described transmission cycle can be by a plurality of transmitter-receivers to obtaining, so that prevent too much data error.

22. the method by distributed power spider lines transmission video and/or audio stream between device comprises:

On described network, produce the cycle initial signal during initial signal in the cycle that do not detect;

Wherein do not detecting other main controller when movable, thereby the transmitter that is connected to described network and becomes the cycle main controller produces described cycle initial signal in cycle;

By following steps time slot is arbitrated, independently carried out by each transmitter, so that obtain to be used to transmit enough time slots of stream:

(i) produce the time slot request according to the cycle initial signal,

(ii) monitor higher priority request for described time slot,

If (iii) do not detect the higher priority request, then obtain described time slot for using, if perhaps detect the higher priority request, rollback and ask different time slots from use then; And

Adopt described time slot to transmit stream, receive for the recipient by described network.

23. method as claimed in claim 22, it is characterized in that, after producing the cycle initial signal, if run into signal conflict or detect another signal, the transmitter that then produces the cycle initial signal stops to produce the cycle initial signal, and does not only produce through just attempting again after the rollback time when detecting the initial signal that other transmitter produces.

24. method as claimed in claim 22 is characterized in that, for etc. step transmission and asynchronous communication all keep the several portions in described cycle.

25. method as claimed in claim 22 is characterized in that, also comprises by each order active flow is distributed in the inferior priority that reduces gradually in the given priority level segmenting priority in transmission.

26. method as claimed in claim 25 is characterized in that, described priority is used to allow to have higher priority in the given priority level during to the time slot arbitration requesting party obtains time slot.

27. method as claimed in claim 25 is characterized in that, described time preferential grade comprises order numerical value.

28. method as claimed in claim 22 is characterized in that, and is encrypted by the communication of described power line communication network.

29. method as claimed in claim 22 is characterized in that, described cycle initial signal is synchronized to the 60Hz cycle timing of power line.

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