CN101874382B - Bi-directional amplifier for data over coax application - Google Patents

Abstract

A disclosed bidirectional amplifier circuit allows the use of coax data transfer protocols (eg, MOCA) on existing and newly developed cable TV systems. Equal bi-directional power amplification can be achieved by using a directional coupler on the AP side of the bi-directional amplifier. According to a general aspect, an apparatus includes a bidirectional power amplifier (1212) configured to amplify a signal having a first direction and to amplify a signal having a direction opposite to the first direction. The apparatus also includes a bidirectional power detector (1202-1204) coupled to the bidirectional power amplifier to (1) detect the power of the signal having the first direction before it is amplified by the bidirectional power amplifier, and (2) detecting the power of the signal having the opposite direction after the signal having the opposite direction is amplified by the bidirectional power amplifier.

Description

The two-way amplifier that is used for the coaxial cable data-transfer applications

Technical field

Present principles relates to the broadband communication network based on cable.More specifically, its method that relates to two-way amplifier and be used for implementing described two-way amplifier.

Background technology

With and will continue to transmit data with coaxial cable.It is the deficiency of the transfer rate that causes of the constraint (constraint) due to coaxial cable and the finite bandwidth that is associated with coaxial cable to a restriction that utilizes other transportation protocol to transmit data with coaxial cable.In cable system, considered use time division duplex two-way amplifier.Yet these amplifiers can not be supported desired speed and other constraint usually.

Summary of the invention

According to total aspect, a kind of equipment comprises the bidirectional power amplifier unit, and described bidirectional power amplifier unit is configured to amplify signal and amplification with first direction to have and first party signal in the opposite direction.Described equipment also comprises the bidirectional power detector cell that is coupled to the bidirectional power amplifier unit, in order to (1) detected the power of the signal with first direction before the signal with first direction is amplified by the bidirectional power amplifier unit, and (2) have rightabout signal amplified by the bidirectional power amplifier unit after detection have the power of described rightabout signal.

According to another total aspect of present principles, amplifier circuit comprises the directional coupler with input and output.Described circuit further comprises the bidirectional power amplifier, the output that described bidirectional power amplifier has bypass mode and has the input of the output that is coupled to directional coupler and be configured to be connected to modulator-demodulator, wherein the input of directional coupler is configured to be connected to access point.Described directional coupler is connected to the access point side of bidirectional power amplifier.Described circuit comprises power detector, and described power detector is connected to directional coupler and is configured to detect up-link power and downlink power.Described circuit comprises the voltage comparator with inverting input and non-inverting input, and each is connected to described power detector inverting input and non-inverting input.Described circuit comprises potential-divider network, and described potential-divider network is connected to the non-inverting input of described voltage comparator and is configured to provides pre-bias voltage to described voltage comparator.Described circuit comprises the switch that is connected to described voltage comparator and described bidirectional power amplifier.Described switch is configured to change in response to the signal that receives from described voltage comparator the mode of operation of described bidirectional power amplifier.

The aspect total according to another, a kind of method are included in the access point side supervision uplink signal of the two-way amplifier in the two-way amplifier circuit or the appearance of down link signal.Described method further comprises: when only down link signal occurring, two-way amplifier is switched to delivery status.

According to another total aspect, a kind of equipment comprises (a plurality of) element that monitors the appearance of uplink signal or down link signal for the access point side of the two-way amplifier in the two-way amplifier circuit.Described equipment also comprises for (a plurality of) element that two-way amplifier is switched to delivery status when only down link signal occurring.

The aspect total according to another, a kind of amplifier circuit is intended to use together with existing CATV system, wherein said CATV system comprises one or more cable branches (cable distribution), and every cable branch has at least one CATV trunk amplifier (trunk amplifier).Described amplifier circuit comprises the two-way amplifier unit, and each the CATV trunk amplifier on itself and cable branch is arranged in parallel.Described two-way amplifier unit makes: in the situation that do not disturb the TV signal that carries on described CATV cable branch or the TV signal that carries on described CATV cable branch do not caused loss, the path (passage) that the coaxial cable data transmit (DOCA) agreement can operate in described CATV system.

The aspect total according to another, a kind of cable system comprises at least one power splitter, described at least one power splitter has at least one and is connected to based on the input of the television service provider of CATV cable and at least one and is connected to the input that the coaxial cable data transmit (DOCA) protocol system, and described at least one power splitter has at least one cable branch output.Described cable system also comprises the CATV trunk amplifier, and described CATV trunk amplifier and at least one cable branch are connected in series.Described cable system also comprises the two-way amplifier circuit, described two-way amplifier circuit be connected in parallel around the described at least one cable branch of described CATV trunk amplifier.

The first side that the aspect total according to another, a kind of method are included in power amplifier detects the signal with specific direction of transfer.Described method comprise use described power amplifier amplification detection to the signal with described specific direction of transfer.The first side that described method is included in described power amplifier detects the signal with direction of transfer opposite with described specific direction of transfer.Described method comprise use described power amplifier amplification detection to the signal with opposite direction of transfer.

The details of one or more embodiments is proposed in following accompanying drawing and description.Even described in a specific mode, also should know to configure in every way or to embody described embodiment.For example, embodiment can be carried out as method, perhaps it is presented as the equipment that is configured to carry out one group of operation, perhaps it is presented as that storage is used for carrying out the equipment of one group of instruction that operates.Consider following detailed description together with accompanying drawing and claim, it is obvious that other side and feature will become.

Description of drawings

Fig. 1 illustrates the exemplary TDF access network framework of simplification.

Fig. 2 is shown in the 802.11MAC sublayer in OSI Reference Model.

Fig. 3 is shown in the embodiment of the TDF transmission entity in OSI Reference Model.

Fig. 4 illustrates the embodiment of communication pattern entrance routine.

Fig. 5 illustrates the embodiment of TDF super frame structure.

Fig. 6 illustrates the embodiment of registration (registration) routine.

Fig. 7 illustrates the embodiment of cancellation (unregistration) routine.

Fig. 8 illustrates the embodiment of survival (alive) notification routines.

Fig. 9 comprises the system diagram of the embodiment of having described the TDF network.

Figure 10 comprises the block diagram according to the embodiment of the AP of Fig. 9 and modulator-demodulator.

Figure 11 is the high-level diagram of embodiment that can implement the system of present principles.

Figure 12 is the block diagram according to the embodiment of the two-way amplifier of the one side of present principles.

Figure 13 is the detailed block diagram according to the two-way amplifier of the embodiment of present principles.

Figure 14 is the schematic diagram according to the embodiment of the two-way amplifier of the one side of present principles.

Figure 15 is the block diagram according to the method for the embodiment of present principles.

Figure 16 is the block diagram according to the other method of the embodiment of present principles.

Embodiment

In order to provide data, services by existing coaxial cable TV system (CATV), at least one embodiment has been disposed access point (AP) and the station (STA) of deferring to time-division function (TDF) agreement in the cable access network.AP is connected the splitter (splitter) that is in hierarchical tree and connecting with STA.In this way, the user is in and can accesses remote I P core network via the cable access network.As illustrated in figure 1, illustrate detailed network topology.

As can be seen from Fig. 1, in this typical access network infrastructure, there is the AP that defers to the TDF agreement, this AP has an Ethernet interface that is connected with IP core network and a coaxial cable interface that is connected with the cable access network.At the other end of cable access network, there is the STA that defers to the TDF agreement, that is, terminal, described STA is connected with the cable access network via coaxial cable interface and is connected with the LAN of family (local area network (LAN)) via Ethernet interface.

According at least one embodiment, according to 802.11 series of canonical, TDF AP and STA are at logical link control sublayer, media access control sublayer and physical layer implementation agreement stack discretely.Yet in media access control sublayer, TDF AP and STA utilize the TDF frame to transmit entity and replace 802.11 frames transmission entities.Like this, the media access control sublayer that is used for TDF AP and STA transmits entity by 802.11 frame encapsulation/decapsulation entities and TDF frame and forms, and the media access control sublayer that is used for deferring to 802.11 AP and STA transmits entity by 802.11 frame encapsulation/decapsulation entities and 802.11 frames and forms.For integrated AP and STA, the TDF frame transmits entity and 802.11 frames and transmits entity and can simultaneously and deposit, with provide 802.11 and the TDF function the two.Can realize two kinds of switchings between pattern by manual or dynamic-configuration.

Basic skills

The main thought of TDF agreement is in coaxial cable medium rather than transmits the IEEE802.11 frame aloft.The purpose of utilizing IEEE 802.11 mechanism is to utilize the hardware and software embodiment of the maturation of 802.11 protocol stacks.

The principal character of TDF is the medium connection control method that is used for transmitting IEEE 802.11 Frames of its uniqueness.That is, it does not utilize conventional IEEE 802.11DCF (distributed coordination function) or PCF (point coordination function) mechanism to exchange the mac frame that comprises MSDU (MAC service data unit) and MMPDU (Medium Access Control (MAC) Management Protocol Data Unit).But it transmits mac frame with the time-division cut-in method.TDF has defined the cut-in method that the frame that is arranged in media access control sublayer transmits the detailed embodiment of entity like this.

For comparison purposes, as shown in Figure 2, we are the IEEE802.11MAC sublayer agreement in OSI Reference Model in this diagram.And in Fig. 3 the definite position of TDF agreement in the diagram OSI Reference Model.

Communication pattern entrance routine

Current, proposed to defer to as described below two kinds of communication patterns at the station of TDF.A kind of pattern is IEEE 802.11 operator schemes of standard, and it observes frame structure and the transfer mechanism that defines in IEEE 802.11 series standards; Another kind of pattern is the TDF operator scheme, will the details of relevant this TDF operator scheme be discussed in paragraph below.At Fig. 4 indicating determine to enter the strategy of which operator scheme when TDF STA starts.In case TDF STA receives synchronization frame from AP, make TDF STA can enter the TDF pattern, if do not receive synchronization frame default in overtime, TDF STA remains unchanged or transfers IEEE 802.11 patterns to.

The TDF protocol function is described

Cut-in method

Physical layer in the TDF station can have the ability of a plurality of data transfer rate, and it allows to carry out the embodiment that dynamic rate switches under the purpose of improving performance and plant maintenance.Current, TDF can support at the station data rate of three types: 54Mbps, 18Mbps and 6Mbps.Mainly provide data, services under the 54Mbps data rate.When for the station, support the 54Mbps data to transmit when having some problem, can temporarily switch to the 18Mbps data rate.6Mbps data rate operator scheme is to design for the purpose of network operation with the station debugging.

Can be before the TDF station enters the TDF Communications routines configuration data speed statically, and keep equivalent data rates in during whole communication process.On the other hand, TDF can also support the dynamic data rate of viability to switch.The criterion that data rate switches can be based on channel signal quality and other factors.

The basic cut-in method of TDF agreement is time division multiplexing (TDMA), and it is by being that different time slots allows a plurality of users to share this channel with same channel distribution.TDF STA one after the other transmits uplink traffic one by one fast, and each TDF STA uses they self time slot in TDF super frame, that assigned by TDFAP.For downlink traffic, the STA shared channel, and by the destination-address information in Frame or management frames and their address are compared Frame or the management frames of selecting take them as target.Fig. 5 illustrate exist m compete simultaneously the up link conveyer can STA the time be used for the typical TDF super frame structure of TDF super frame and the example of time slot allocation.

As shown in Figure 5, there be tdfTotalTimeSlotNumber fixing time slot in each TDF super frame, and it is comprised of following: a synchronization slot that is used for from TDF AP to TDF STA tranmitting data register synchronizing information; Contention (contention) time slot that is used for sending the registration request that uplink time slot is distributed; Send to TDF AP tpfUplinkTimeSlotNumber the uplink time slot that data and some management frames are used one by one by the TDF STA of registration; And transmit data and register tpfDownlinkTimeSlotNumber the downlink time slots that the response management frame uses to modulator-demodulator by TDF AP.Except synchronization slot, all other time slots that are named as public time slot have the identical duration that length equals tdfCommonTimeSlotDuration.The value of definition tdfCommonTimeSlotDuration for the peak data rate pattern, transmits at least one maximum IEEE 802.11PLCP (Physical layer convergence protocol) protocol Data Unit (PPDU) to allow in a standard time slot.The duration tdfSyncTimeSlotDuration of synchronization slot is shorter than the duration of public time slot, and this is because the clock synchronous frame that transmits from TDF AP to TDF STA in synchronization slot is shorter than 802.11 Frames.

As a result, can calculate the duration of a TDF super frame that is defined as tdfSuperframeDuration by following formula:

tdfSuperframeDuration＝tdfSyncTimeSlotDuration+tdfCommonTimeSlotDuration*(tdfTotalTimeSlotNumber-1)

Relation between tdfTotalTimeSlotNumber, tdfUplinkTimeSlotNumber and tdfDownlinkTimeSlotNumber satisfies following equation:

tdfTotalTimeSlotNumber＝tdfUplinkTimeSlotNumber+tdfDownlinkTimeSlotNumber+2

The number of the uplink time slot that distributes for TDF STA in the TDF super frame in addition, can be changed into tdfUplinkTimeSlotThreshold from 1.Correspondingly, in the TDF super frame, available downlink time slots can be changed into (tdfTotalTimeSlotNumber-2-tdfMaximumUplinkTimeSlotNumber) from (tdfTotalTimeSlotNumber-2).At every turn when one of existence requires the TDF STA of uplink time slot, TDF AP will draw (deduce) one or more time slots from available downlink time slots, and then with these time slot allocation to TDF STA, as long as after this uplink time slot number be no more than tdfMaximumUplinkTimeSlotNumber.In different embodiments, the value of tdfMaximumUplinkTimeSlotNumber may change.But must careful selection so that exist at least a downlink time slots to use for the TDF STA that is associated, in order to guarantee the QoS of data, services.In addition, can merge all time slots in succession that will transmit for same direction, used by same TDF STA or AP sending continuously mac frame, thereby avoid the waste of locating at these time slot edges (edge) that caused by unnecessary conversion and assurance (guarding).

In current embodiment, tdfCommonTimeSlotDuration is about 300us, it transmits at least one maximum 802.11PPDU for TDF STA in a public time slot of 54M pattern be enough, and there are 62 time slots altogether in each TDF super frame.In these time slots, in this way, there are 20 uplink time slots and 40 downlink time slots.When having 20 STA, can guarantee that each TDF STA can use the downlink data rate of uplink data rate and the shared 30Mbps (40 continuous time slots) of 680kbps; When having 30 STA, can guarantee that each TDF STA can use the downlink data rate of uplink data rate and the shared 22.5Mbps (30 continuous time slots) of 680kbps.TdfMaximumUplinkTimeSlotTimeNumber is 30.At last, be about 18.6ms as the value of the tdfSuperframeDuration of duration altogether of 61 public time slots and 1 synchronization slot, and for different purposes, it can be defined as different values.For example, if only there is 1 TDFSTA, can guarantee that it has 4 time slots with the downlink data rate of the uplink data rate of realizing about 18Mbps and the 18Mbps (4 continuous time slots) of self.In this way, the value as the tdfSuperframeDuration of duration altogether of 9 data time slots and 1 synchronization slot is about 4ms.

The form of frame

In 802.11 standards, there are three main frame types.The usage data frame is with from a station to another station swap data.Depend on network and some different types of Frames can occur.Use control frame together with Frame come together execution area cleaning (area clear) operation, channel obtains safeguards the function of (carrier-sensing maintenance) with carrier detect and to the affirmative acknowledgement of the data that receive.Control frame and Frame are worked together with the delivering data reliably from a station to another station.More specifically, a key character of data frames exchange is to have acknowledgement mechanism, and correspondingly exist to be used for each down link unicast frame reply (ACK) frame, in order to reduce the possibility of the loss of data that causes due to insecure wireless channel.At last, management frames is carried out monitoring function: use management frames to add and to leave wireless network and move related (association) from an access point to another access point.

Yet, in the TDF system, because TDF STA waits for synchronization frame from TDF AP passively to find target TDF AP, therefore, do not have exploration (probe) claim frame to classics and the demand of probe response frame.In addition, in coaxial cable rather than aloft switching frame, therefore, needn't define the node problems that RTS and CTS frame come cut-back region and prevent from hiding, and needn't define the reliability that the ACK frame is guaranteed the delivering data frame.

Therefore, in the TDF agreement, we only use some useful 802.11MSDU and MMPDU type for the data that transmit by the coaxial cable situation.For example, we utilize the data subtypes in data frame type, and it is used to encapsulate than the data on upper strata and will be sent to another station from a station than the data on upper strata.In addition, in order to tackle the needs of clock synchronous in the TDF system, we have defined the management frames-synchronization frame of new kind; And for realizing the function of uplink time slot request, distribution and release, we define the management frames of other four kinds, that is, and and registration request, registration response, de-registration request and survival notice.

Generally, we have defined four kinds of new subtypes in the management frame in the TDF agreement.Following form definition the type that increases in the TDF agreement and effective combination of subtype.Form 1 shows the effective type and the subtype that are used for the TDF frame that increases in the TDF agreement.

Form 1

Type specification	Subtype specification
		Management	Synchronously
Management	Registration request
		Management	The registration response
Management	De-registration request
		Management	The survival notice

TDF accesses routine

TDFAP finds and the clock synchronous routine

The TDF agreement depends on timing information to a great extent to the distribution (distribution) of all nodes.At first, TDF STA intercepts synchronization frame to determine whether to exist available TDF AP.In case TDF STA enters the TDF Communications routines, come adaptive local timer with synchronization frame, TDF STA will determine whether taking turns to it based on this this locality timer and send uplink frame.At any time, TDF AP is main frame and TDF STA is slave in Synchronization routines.Further, if TDF STA does not also receive any synchronization frame from the AP that is associated within the predetermined threshold value period (it is defined as tdfSynchronizationCycle), it will think that this AP has withdrawed from service, and then it will stop the TDF communication process and begin to seek any TDF AP by again intercepting synchronization frame.

In the TDF system, should will synchronize to common clock with all STA that same TDF AP is associated.TDF AP should periodically transmit and be known as synchronous special frames with the modulator-demodulator in synchronous its local network, describedly is known as the clock information that synchronous special frames comprises TDF AP.Each TDF STA should safeguard local timing synchronization function (TSF) timer, synchronizes with the TDF AP that is associated to guarantee it.After receiving synchronization frame, TDF STA should accept the timing information in frame all the time.If the TSF timer of reception TDFSTA is different from the timestamp in the synchronization frame that receives, receives TDF STA its local timer should be set according to the value of the timestamp that receives.Further, it can increase this locality processing that little biasing is undertaken by transceiver with explanation (account for) to the timing value that receives.

TDF AP should be to transmit at each TDF super frame time quantum and generates a synchronization frame and send this synchronization frame in the Sync of each TDF super frame time slot.

The registration routine

Whole registration routine has been described to Fig. 6 n-lustrative.In case TDF STA has obtained the timer synchronizing information from synchronization frame, it will learn when begin time slot 0.If TDF STA and any TDF AP are unconnected, it will be attempted to the specific TDF AP registration that sends synchronization frame by send registration request frame to TDF AP during contention slots, and described contention slots is the second time slot in the TDF super frame.Should design modestly the duration of the contention slots that equals tdfCommonTimeSlotDuration and the structure of registration request frame, to allow to send tdfMaximumUplinkTimeSlotNumber registration request frame at least in a contention slots.Based on this design, contention slots is divided into the sub-slots of tdfMaximumUplinkTimeSlotNumber equal length.

As long as TDF STA finds target TDF AP, it will according to following methods, select a sub-slots to send registration request frame to TDF AP in contention slots:

A. at every turn when TDF STA is assigned with uplink time slot, it is defined as uplink time slot number tdfAllocatedUplinkTimeSlot, that distribute (number) with storage, its indicate this time slot in whole uplink time slot pond (pool) the position and its scope from 1 to tdfMaximumUplinkTimeSlotNumber.

B. when TDF STA required uplink time slot at every turn, TDF AP should distribute identical uplink time slot to identical TDF STA with trying one's best.

C. when determining to select which sub-slots to send registration request frame, if there is the tdfAllocatedUplinkTimeSlot value of storage, TDF STA bundle timeslot number is set to identical with tdfAllocatedUplinkTimeSlot; If there is no such value, TDF SAT will select a sub-slots randomly in tdfMaximumUplinkTimeSlotNumber available sub-slots.TDF STA will send registration request frame to TDF AP in the random sub-slots of selecting.

The purpose of this operation is to reduce the chance of conflict when many STA start simultaneously and attempt simultaneously to same TDFAP registration.

In registration request frame, TDF STA will be listed in all data rates and carrying some useful information such as the carrier wave/noise ratio of the signal that receives of its support at that time.It can from the highest data rate, utilize the different data rate of supporting to send some registration request frame in succession.After sending frame, TDF STA will intercept the registration response frame from TDF AP.

After TDF STA receives registration request frame, based on following methods, TDF AP will return to different types of registration response frame to TDF STA in downlink time slots:

If the uplink time slot that has A. distributed equals tdfMaximumUplinkTimeSlotNumber, TDF AP will put into the uplinkTimeSlotUnavailable designator in frame main body.

If B. TDF AP is not supported in listed any data rate in supportedDataratesSet in the registration request management frames, TDF AP will put into the unsupportedDatarates designator in frame main body.

If the public data rate that C. exists the uplink time slot can be used for distributing and TDF AP and TDF STA all can support, AP will distribute a uplink time slot and select suitable public data rate according to some information such as carrier wave/noise ratio in the registration request frame of STA, and then send registration response frame to TDF STA.In frame main body, can comprise the relevant uplink time slot that distributes and the information of selected data rate.

After the registration routine of success, TDF STA and TDF AP will reach an agreement to using which uplink time slot and data rate.

Segmentation (fragmentation)/solution segmentation routine

In the TDF agreement, the time slot duration that MSDU is transmitted is fixed as tdfCommonTimeSlotDuration.In some data rate,, can not transmit in single time slot during greater than threshold value when the length of MSDU.So, when being used for data frame length that up link transmits in being defined as tdfFragmentationThreshold and depending on different pieces of information speed and during the threshold value that changes, with before transmitting it, should carry out segmentation at this Frame of scheduling to it.For all segmentations except last segmentation, the section length of frame should be the eight bit byte (Octets) (tdfFragmentationThreshold eight bit byte) of equal number, and last segmentation can be less.After segmentation, the frame after segmentation should be put into and wait to send out (outgoing) formation, to be sent to TDF AP.Can transmit at the TDF frame and move this segmentation routine in entity or transmit at the TDF frame tdfFragmentationThreshold that dynamically arranges in entity by use and move this segmentation routine in than the upper strata.

At TDF AP end, each segmentation that receives comprises permission and re-assembly the information of (reassemble) whole frame from the composition segmentation of frame.The head of each segmentation comprises TDF AP and re-assemblies the following information that frame uses:

A. frame type (Frame type)

The address (Address of the sender) of the transmit leg that B. 2 (Address 2) field obtains from the address

C. destination-address (Destination address)

D.Sequence Control (sequence control) field: this field allows TDF AP to check that all enter segmentation and all belong to same MSDU, and described segmentation should be re-assemblied and is sequence.Serial number in the SequenceControl field keeps identical to all segmentations of MSDU, and the segment number in Sequence Control field is to each segment increasing.

E.More Fragments (more segmentations) designator: indicating this to TDF AP is not the last segmentation of Frame.Only have the last of MSDU or unique (sole) segmentation to be set to zero by this bit.Other segmentation of all of MSDU should be set to one by this bit.

TDF AP should come reconstruct MSDU by the sequential combination segmentation according to the segment number son field of Sequence Control field.Be not set to zero segmentation if also receive More Fragments bit, TDF AP will know that frame is also imperfect.TDF AP one receives More Fragments bit and is set to zero segmentation, and it is just known for this frame and may not receive more segmentation.

TDF AP should be each frame that is receiving and safeguards the reception timer.Also have the tdfMaxReceiveLifetime attribute, it specifies the maximum time amount that a frame allows that receives.Start when receiving first segmentation of MSDU and receive timer.If the received frame timer surpasses tdfMaxReceiveLifetime, TDF AP abandons the segmentation of all receptions of this MSDU.If receive the additional segmentation of this MSDU after the tdfMaxReceiveLifetime that surpasses (directed) MDSU that is managed, should abandon these segmentations.

Up link transmits routine

After TDF AP receives registration response frame, TDF STA with the analysis frame main body to check whether it has been given uplink time slot.If be not given uplink time slot, it will stop applying for uplink time slot for a moment and subsequently.If be given uplink time slot, it will be used during the time slot that the data rate of registration response frame indicating is being assigned and begin to transmit uplink traffic.

Up link during the time slot of assigning transmits begins the place, if exist at least one to wait to send out a frame in the outgoing queue of TDF STA, TDF STA will send the first frame in its outgoing queue to TDF AP.After this, TDF STA will check that the length of the second uplink frame and assessment possibility send the second uplink frame in the residue duration of the time slot of assigning.If can not, it will send the second uplink frame in stopping up link transmission routine and waiting for during next TDF super frame in the time slot of assigning.If of course, it will send the second frame to destination TDF AP immediately.Send routine and will continue in this way operation, until the time slot of assigning finishes or do not have any uplink frame that will transmit.

Down link transmits routine

In whole TDF Communications routines, total downlink time slots number may dynamically change due to the STA number that is associated that changes.When TDF AP prepares to send frame to the STA that is associated, it with the time remaining in remaining downlink time slots be used for using (agreed) data rate of deciding through consultation to transmit the required duration of specific descending chain circuit frame comparing.Then based on this result, it will determine whether should transmit this frame with specific data rate during this TDF super frame.In addition, TDF

AP does not need any descending chain circuit frame is carried out segmentation.

When not being when sending the time of uplink traffic for the STA that is associated, STA will always intercept channel so that the possible descending chain circuit frame of discovery take it as target.

Nullify routine

As shown in Figure 7, if TDF STA determines to withdraw from the TDF Communications routines, it thereon during the line link time slot the introversive TDF AP that is associated send the de-registration request frame so that notice TDF AP is released to the uplink time slot resource that its distributes.After receiving the de-registration request frame, TDF AP will make the uplink time slot of assigning for this TDF STA vacant (free) and put it into vacant time slot pond in the future.

The survival notification routines

Referring now to Fig. 8, for releasing resource as quickly as possible when TDF STA collapses suddenly or closes, TDF STA must report its viability by periodically sending the survival notification frame to TDF AP in during line link time slot period thereon.If do not have any survival notice in the period in the predetermined threshold value that is named as tdfAliveNotificationCycle, the TDF AP that is associated will think that TDF STA has withdrawed from service, and then be released to the uplink time slot that this TDF STA distributes, just as receive the de-registration request frame from this TDF STA.

In order to ensure the TDF with many rate capacities STA's and deposit and interoperability, this normalized definition one group of rule all should following of all stations:

A. should transmit synchronization frame with the minimum speed limit in the set of TDF basic rate, make these synchronization frames to be understood by all STA.

B. should send all frames with destination unicast address on the data rate of supporting of selecting by login mechanism.Unicast frame will not transmitted with the speed that receiving station does not support in the station.

C. should transmit with the flank speed in the set of TDF basic rate all frames with destination multicast address.

As mentioned above, the TDF agreement can be replaced conventional 802.11DCF (distributed coordination function) or PCF (point coordination function) mechanism.Such system can utilize WLAN (802.11) network of widespread deployment and may become the more and more advantage of ripe and cheap WLAN chipset.This system provides the solution of cost-effective for the two-way communication of catv network by transmit the WLAN signal in cable system, even if in environment aloft rather than transmit in cable system/receive and created the WLAN agreement.In this system, the basic cut-in method of TDF agreement is TDMA, and it is by being that different time-gap allows a plurality of users to share this same channel with same channel distribution.The time slot at each TDF uses at the station in TDF super frame, assigned by TDF AP (access point) this TDF station self one after the other transmits uplink traffic one by one fast.For downlink traffic, these station shared channels (for example, as shown in the TDF of Fig. 5 super frame), and by the destination-address information in these frames and their address being compared select the frame take them as target.

With reference to Fig. 9, show typical TDF network 900.Network 900 provide from subscriber household 910 with are connected to the internet connection of (perhaps other resource or network) 930. Subscriber household 910 and 920 is communicated with access point (AP) 940 by cable system 950.AP 940 can be positioned at the adjacent place of family 910 for example and 920, perhaps is positioned in the apratment building thing that comprises family (apartment in this case) 910 and 920.For example, can have AP 940 by cable operator.AP 940 further is coupled to router 960 by ethernet network 970.Router 960 also is coupled to internet 930.

As should be understood that, term " coupling " refer to direct connection (there is no intermediary's assembly or unit) and indirect joint (one or more intermediaries assembly and/or unit) both.Such connection can be for example wired or wireless, and permanent or temporary transient.

Subscriber household 910 and 920 can have various configuration, and each family can differently be configured.Yet, as shown in network 900, subscriber household 910 and 920 each comprise respectively station (being known as modulator-demodulator) 912 and 922.Modulator-demodulator 912,922 is coupled to the first main frame (main frame 1) the 914,924 and second main frame (main frame 2) 916,926 by Ethernet 918,928 respectively.Each main frame 914,916,924 and 926 can be for example computer or other processing unit or communicator.

Exist network 900 can allow a plurality of main frames (for example, 914,916,924 and 926) to be connected to the whole bag of tricks of router 960.Four kinds of embodiments below are discussed, for simply, are only considered modulator-demodulator 912 and main frame 914 and 916.

In the first method, modulator-demodulator 912 serves as another router.IP address by main frame 914 and 916 identifies main frame 914 and 916, and modulator-demodulator 912 will be from the IP Packet routing of main frame 914 and 916 to router 960.The method 1 typically needs modulator-demodulator 912 operation router softwares, and this needs extra memory and the disposal ability of increase.

In the second method, modulator-demodulator 912 serves as bridger (bridge).Wireless distribution system (WDS) mechanism of modulator-demodulator 912 and AP 940 Application standards comes transfer layer 2 to divide into groups to router 960. Main frame 914 and 916 is controlled (MAC) address by its media interviews and is identified.The method 2 is parts of 802.11 standards and can serves simultaneously a plurality of main frames.Yet not every AP and modulator-demodulator are all supported WDS, and those support AP and the modulator-demodulator of WDS often only to possess limited support.For example, for some AP and modulator-demodulator, you can not use Wi-Fi protection access (WPA) together with WDS, and this may introduce safety issue.

In third method, modulator-demodulator 912 uses MAC camouflage (masquerade) source MAC (source is one of main frame 914 and 916) of Ethernet grouping to be changed into the MAC Address of himself.Therefore from the angle of router 912, router 960 is only seen modulator-demodulator 912.Utilize the method, modulator-demodulator 912 once only can be served a main frame.

In other method, the encapsulation that describes in further detail below modulator-demodulator 912 uses.Each in above method has merits and demerits, and these merits and demerits may depend on embodiment and change.Yet, method for packing provides specific advantage, these specific advantages are that this method for packing allows modulator-demodulator simpler by not needing modulator-demodulator to move router software usually, does not typically introduce safety issue, and can once serve a plurality of main frames.

In addition, this method for packing has avoided by using single WLAN grouping to transmit each grouping from main frame the large expense that is associated with first three methods.Thereby first three methods causes the expense for the WLAN grouping of each grouping of shifting from main frame, and has reduced accordingly throughput.Typically increased the weight of this poor efficiency in the TDF environment.In the TDF environment, the duration of time slot is fixed, and time slot is designed to only allow to transmit a WLAN grouping in a time slot.Thereby, only can transmit a host packet in each time slot.

Correspondingly, this method for packing provides one or more in various advantages usually.For example, such advantage comprises: the fail safe of simpler router design and operation, increase, serve a plurality of main frames, and the efficient and the throughput that increase.

In a word, at least one embodiment of this method for packing comprises that with a plurality of Ethernet packet encapsulation be a WLAN grouping.This WLAN grouping will be the same with the maximum length that the TDF time slot allows large.AP (for example, another modulator-demodulator) is descapsulated into the WLAN grouping each Ethernet grouping and they is sent to router.For the communication on opposite direction, modulator-demodulator sends to (a plurality of) main frame with decapsulation WLAN grouping and with each Ethernet grouping.

With reference to Figure 10, legend 1000 comprises a plurality of modulator-demodulators (wherein two are illustrated clearly) and AP.This legend comprises modulator-demodulator #11010, modulator-demodulator #N 1020 and AP 1030, and each in modulator- demodulator 1010 and 1020 is coupled to AP 1030 by cable system 1040.Another embodiment is used the cable system that separates for each modulator-demodulator.

Modulator- demodulator 1010 and 1020 and AP 1030 comprise the functional unit of same names, although some outside difference and assembly itself of connecting is for modulator-demodulator and the different function of AP execution.Thereby, provide public unit to come as modulator-demodulator and AP.Yet, should know to be modulator-demodulator and the different unit of AP design, those required functions of modulator-demodulator or AP are only carried out respectively in this different unit.

Modulator-demodulator 1010 comprises: local application layer 1011, tcp/ip layer 1012 afterwards, bridger 1014 afterwards.Bridger 1014 is coupled to Ethernet interface 1015, packet aggregation/disaggregation module (PADM) 1016 and WLAN interface 1017.PADM 1016 also is coupled to WLAN interface 1017.Ethernet interface 1015 is coupled to ethernet network 1052, and ethernet network 1052 is coupled to the first main frame (main frame 1) the 1054 and second main frame (main frame 2) 1056.

Modulator-demodulator 1020 is similar to modulator-demodulator 1010.Yet modulator-demodulator 1020 is coupled to ethernet network 1062, and ethernet network 1062 is coupled to the first main frame (main frame 1) the 1064 and second main frame (main frame 2) 1066.Be shown the assembly of modulator-demodulator 1020 identical with the assembly of modulator-demodulator 1010.Yet, should be clear, setting up modulator- demodulator 1010 and 1020 and in modulator- demodulator 1010 and 1020 whens operation, for example various configuration parameters are with difference.

AP 1030 comprises: local application layer 1071, tcp/ip layer 1072 afterwards, bridger 1074 afterwards.Bridger 1074 is coupled to Ethernet interface 1077, PADM 1076 and WLAN interface 1075.PADM 1076 also is coupled to WLAN interface 1075.Ethernet interface 1077 is coupled to ethernet network 1082, and ethernet network 1082 is coupled to router one 090 then.WLAN interface 1017 and 1075 is coupled by cable system 1040 with communicating with one another.

Router one 090 further is coupled to internet 1095.Thereby, main frame 1054,1056,1064,1066 and internet 1095 between exist to connect.

Various local application layers (1011,1071) are for the index bed that moves local application and connect with other layer of framework.Various tcp/ip layers (1012,1072) are for operation TCP/IP and the index bed of the service (comprise with other layer of framework and connecting) that is provided by such layer are provided typically.Various Ethernet interfaces (1015,1077) are be used to the standard cell that is attached to ethernet network or connects from ethernet network. Such interface 1015,1077 transmits and receives the Ethernet grouping and operates according to Ethernet protocol.

Various WLAN interfaces (1017,1075) are be used to the unit that is attached to wlan network or connects from wlan network. Such interface 1017,1075 transmits and receives WLAN grouping and according to the WLAN protocol operation.Yet in legend 1000, WLAN interface 1017,1075 is actual to be coupled to cable system 1040 rather than to use radio communication.

Can implement Ethernet and WLAN interface 1015,1017,1075 and 1077 with for example hardware such as being used for the plug card (plug-in card) of computer.Can also most of implement this interface with software, this software is such as using the instruction of being implemented by processing unit to come the program of the function of executive's interface.Such interface will generally include for (for example receiving actual signal, connector) and (for example be used for signal that buffering receives, transmission/reception buffer) part, and typically comprise the part (for example, signal processing chip is whole or a part of) for the treatment of signal.

Various bridgers (1014,1074) are to forward the unit of grouping between Ethernet interface and WLAN interface.Can be with software or hardware implementation bridger, perhaps bridger can be only logic entity.Comprise processing unit (such as integrated circuit) or in one group of instruction of the upper operation of processing unit (such as the processor of operation bridger software) for the embodiment of the standard of bridger.

PADM 1016 and 1076 carries out various functions, comprises the packet encapsulation and the decapsulation that are described further below.Can make up to implement PADM 1016 and 1076 with software for example, hardware, firmware or certain.The implement software scheme comprises for example one group of instruction such as the program of moving on processing unit.The hardware implementation scheme comprises for example special chip such as application-specific integrated circuit (ASIC).

Most of existing cable systems are based on two-way time division duplex (TDD) system of cable and utilize two-way amplifier.Yet these amplifiers have some restrictions.At first, up link and downlink power grade can not be identical or near identical.The second, bi-directional ring (two way loop) has the Potential feasibility that vibrates under the isolation condition of bad luck.The 3rd, (for example using MOCA or other DOCA agreement owing to working as to existing cable system, advanced coaxial cable data transmit-problem that suffers from when attempting bypass CATV trunk amplifier ADOC) time, can not use these amplifiers in cable system newly developed.

The bidirectional power amplifier that uses present principles is a kind of possible solution of implementing in the system based on cable with tdd mode as MOCA and other DOCA system.The two-way amplifier of present principles can solve the problems referred to above by the following advantage that is better than known embodiment is provided: the 1) Bi-directional amplifier of equal power; 2) vibration that reduces; 3) be suitable for cable system newly developed; 4) the simple detection; And 5) respond fast and there is no failed operation.

As will be described in further detail in the following, can in existing cable system Anywhere, particularly implement the embodiment of the two-way amplifier of present principles between access point (AP) and user's modulator-demodulator.

Figure 11 shows the exemplary high level system diagram 1100 of the two-way amplifier that can implement present principles.(pool floor) 1108 at the bottom of system 1100 has many elements and can comprise the core layer 1102 and pond that connects all other network and service.Core layer is usually by switch 1104 and controller 1106 (for example, Broadband Remote Access Server-BRAS) consist of.The service of communicating by letter with core layer or the example of network comprise voice gateways 1114, IPTV/VOD 1116, internet 1118 and DOCA network management system 1120.Those skilled in the art will recognize also can be with various other services and/or network to connecting core layer 1102.

At the bottom of the pond, 1108 communicate and are access point (AP) in essence with core layer 1102, and all modem networks are connected to this access point (AP) by the online terminal of EPON (OLT) 1110 or by access switch 1112.The router of optical switch 1122 or other type is connected to access point 1108 on one or more less network of user's modulator-demodulator 1126a of cable connection.When using DOCA network management system 1120 (perhaps systems of any other MOCA type) connecting to send data on the cable system of modulator-demodulator 26a, carrying DOCA agreement (DOCAP) 1124 on this cable.

EPON OLT1110 is connected to diffuser (disperser) 1128, and diffuser 1128 should connect " diffusion " to one or more optical network unit (ONU) 1130.Then ONU is distributed to one or more modulator-demodulator 1126b in the network that the cable of modulator-demodulator connects with signal.The two-way amplifier of present principles can be between for example access point 1112 and modulator-demodulator 1126a, perhaps between EPON OLT 1110 and modulator-demodulator 1126b Anywhere.

Intraware by the interconnected core layer 1102 of fibre circuit 1131 (for example, core switch 1104 and Broadband Remote Access Server 1106), and usually by coaxial cable 1132, gateway 1114, IPTC/VOD 1116, the Internet 1118 and DOCA network management system 1120 are connected to core layer 1102.At the bottom of also by fibre circuit 1131, core layer 1102 being connected to the pond.

Can use equally fibre circuit 1131 that OLT 1110 and access switch (access point) 1112 are connected to diffuser 1128 and optical switch (router) 1122.Use fibre circuit 1131 diffuser 1128 can be connected to ONU 1130.Via Ethernet cable 1134, ONU 1130 and optical switch (router) 1122 are connected to DOCAP 1124, and via coaxial cable 1132, modulator-demodulator 1126 are connected to DOCAP 1124.

Figure 12 shows the block diagram according to the two-way amplifier 1200 of the embodiment of present principles.Two-way amplifier 1200 is coupling between AP and modulator-demodulator, and comprise directional coupler 1202, be connected to the power detector 1204 of directional coupler, dividing potential drop (voltagedivision) network 1206 of communicating by letter with a side of power detector, and voltage comparator 1208.Voltage comparator 1208 receives signal and is connected to single-pole double throw (SPDT) switch 1210 from power detector.Amplifier 1212 with bypass mode is connected to directional coupler 1202 and SPDT switch 1210.

For example can be by power detector 1204, make up to form the bidirectional power detector cell with the directional coupler 1202 of power detector 1204 combination or by other of the element that comprises potential-divider network 1206, voltage comparator 1208 and/or switch 1210.For example can be separately form the bidirectional power amplifier unit by amplifier 1212 or by amplifier 1212 and one or more other elements combination from Figure 12.

Figure 13 is schematically showing according to the embodiment of the two-way amplifier 1200 of the embodiment of present principles.

The operation of two-way amplifier 1200 is described referring now to Figure 12 and Figure 13.Other the schematic embodiment that should be understood that amplifier 1200 is possible and is foreseeable.Further, below operation is illustrated schematic embodiment in Figure 13, but those of ordinary skill in the art will recognize and can revise described operation to adapt to other schematic embodiment.

Continue described operation, amplifier 1212 comprises bypass functionality, thereby when it was in magnifying state, it can provide+gain of 15dB, and when it is in bypass mode, it can provide-and the insertion loss of 2dB.The mode of operation of amplifier 1212 is under the control of SPDT switch 1210.

Two-way amplifier 1212 with bypass mode is cores of amplifier 1200.When amplifier 1212 was in amplification mode, it can provide the gain greater than 15dB, and when it is in bypass mode, and it can provide-insertion loss of 2dB.Can switch this two states by switch 1210 and/or by additional external module.As from the example of Figure 13 as seen, two amplifiers 1213 will be in magnifying state and other two amplifiers 1213 are in bypass mode in each state (transmit or receive).

Directional coupler 1202 is high performance directional couplers that single direction (single way) power detection (opposite with known commercial bidirectional coupler (two way coupler)) can be provided.Coupler 1202 comprises two directional coupler 1302a and the 1302b that is configured to detect respectively transmission (up link) power and reception (down link) power.Directional coupler 1202 can provide have-the 1dB insertion loss and-10dB coupling loss, greater than the directivity (directivity) of 25dB, and provide the directivity of 28dB at the 1Ghz place.

Power detector 1204 is high sensitivity power detectors and comprises RF power detector 1304a, the 1304b that the RF signal can be converted to dc voltage, wherein described dc voltage is maintained the ratio fixing with RF power.RF power is higher, and the dc voltage of output is higher.Dc voltage after two conversions is input to voltage comparator 1208.RF power detector available on the market for example can be realized, the sensitivity of-45dBm RF power detection.

Voltage comparator 1208 has two inputs (anti-phase and noninverting) and provides two output states indications one based on the input that receives from power detector 1204.For example, if non-inverting input greater than inverting input, comparator 1208 is the output HIGH voltage level, on the contrary, if non-inverting input lower than inverting input, comparator is with the output LOW voltage level.(for example ,～0.1V) come the prebias non-inverting input by the low-down dc voltage that provides by potential-divider network 1206.This prebias has prevented the abnormality of comparator 1208 during the signal input.

The output of SPDT switch 1210 is controlled in the output of voltage comparator 1208, makes the state that SPDT 1210 can control amplifier 1200.

As skilled in the art will appreciate, when not having the signal of transmission on up link and both downlink, two-way amplifier 1200 is in " reception " state of setting up as the pre-bias voltage that is provided to the non-inverting input of comparator 1208 by potential-divider network 1206 (namely, modulator-demodulator is opened (open) to the AP amplifier, and AP is to the bypass of modulator-demodulator amplifier).When having the uplink signal that transmits, because voltage comparator output will not change (perhaps from high tumble to low), two-way amplifier will still remain on " reception " state.

When having the down link signal that transmits, due to the increase of voltage on inverting input, comparator 1208 will overturn or the change state.This will impel switch 1210 two-way amplifier to be switched to " transmission " state.When completing the down link signal transmission, the voltage on inverting input reduces to 0 (perhaps substantially to 0), and comparator 1208 is by responding to returning to overturn and impel switch 1210 two-way amplifier to be switched back " reception " state.

As used herein, the equal power Bi-directional amplifier mean on both direction obtain equal-wattage output (～0dBm) and identical gain (～26-30dB) ability.Those skilled in the art will recognize the directivity (for example ,～20) due to power detector, be not easy to realize keeping the Bi-directional amplifier of equal-wattage output in tdd mode two-way (two way) communication system.

One side according to present principles, and in order to realize the equal power Bi-directional amplifier, access point (AP) side at amplifier is arranged power detector 1204, and will (for example ,～0.1V) put on the non-inverting input of comparator 1208 from the low pre-bias voltage of potential-divider network 1206.By this design, even use the power detector with relatively poor directivity can realize that also equal-wattage amplifies.

The main cause of such configuration of directional coupler 1202 is: when in the AP of two-way amplifier side and modem side or only when modem side is placed directional coupler, typically, system will not be to work all the time.1), by directional coupler being placed on the separation side/opposite side of two-way amplifier there are relevant with placement directional coupler 1,202 three kinds of situations or situation:, sew (signal leakage) to the amplifier signal of directional coupler and may cause fault; 2) two directional couplers are placed on two-way amplifier modem side-according to the WiFi agreement, if do not have signal (that is, up link or down link) at the either side of amplifier, two-way amplifier should be in accepting state.During in modem side, if transmit down link signal, due to the isolation of two-way amplifier, down link signal can not arrive at directional coupler when directional coupler.Therefore, two-way amplifier remains on receiving mode and system will be out of order; And 3) by two directional couplers are placed on the AP side, system will work as described in present principles.

For example, coupler and/or detector are in the system of opposite side of amplifier above-mentioned sewing may occur therein.May sew due to the fact that, namely, when transmitting uplink signal (namely, modulator-demodulator is to AP) time, because the power after some amplify is leaked to the power detector of AP side, so will be greater than the signal that detects from modem side (backward) detector from the signal of AP side (forward direction) power detector detection.This will cause voltage comparator to switch to transfer mode from receiving mode.Has similar result for down link signal.

Other embodiment is placed on power detector the modem side of amplifier, and/or the prebias inverting input.

According on the other hand, present principles provides the vibration that reduces.This is due to the fact that, only has a physical signal paths, therefore loop oscillation can not occur.In addition, do not need outside high selectivity band pass filter (BPF).

Result as the embodiment of present principles does not have strict requirement for directional coupler 1202.Like this, can use directional coupler commonly used in the embodiment of present principles.This is due to the fact that, if we implement the directional coupler (power detector) of AP side and modem side, the detector signal that deducts the AP side from the detector signal of modem side will be determined the mode of operation of switch 1210, and determine thus the state of two-way amplifier 1212.By two directional couplers being placed on the AP side of two-way amplifier 1212, down link signal and uplink signal the two by directional coupler 1202 time, will be almost identical power grade.Therefore, even utilize the directional coupler (for example, the 20dB isolation) with relatively poor directivity, the 20dB allowance can guarantee that also the subtraction value will be suitable and guarantee thus the mode of operation of switch 1210.

According to the embodiment of present principles, all assemblies provide the operation response of nanosecond.Therefore, total time of delay less than 300ns (for example, directional coupler 1202-is less than 10ns, power detector 1204-85ns, voltage comparator 1208-40ns, SPDT 1210-12ns, and power amplifier 1212-100ns), this is less than the normally requirement of the tdd mode communication system of some microseconds.

According to the Potential feasibility of fault, they can be divided into some situations:

Situation 1: when do not have signal input (that is, not transmitting or received power) time-amplifier 1212 will be in accepting state (, open in the path from the modulator-demodulator to AP) in both sides;

Situation 2: when having the signal that transmits from AP to modulator-demodulator, the power of forward detection (for example, 0.2-0.5V) will than the power of backward detection (＜0.1V) much bigger, so voltage comparator 1208 will overturn and amplifier 1212 will switch to delivery status (that is, the path from AP to modulator-demodulator); And

Situation 3: when having the signal that transmits from modulator-demodulator to AP, the power of backward detection (for example 0.6-0.8V) will than the power of forward detection (＜0.1V) much bigger.Due to the non-inverting input mouth place at power comparator 1208 exist prebias resistive (resistive) voltage (for example, 0.1V), so amplifier 1212 will remain on " reception " state.Note, be in the fact of accepting state due to the supposition amplifier, the power of backward detection is the signal that detects after being exaggerated.

Be also noted that, in normal TDD operation, a signal-be only uplink signal or down link signal only occur at every turn.Further, between such signal occurs, amplifier will typically return to accepting state.Yet if a plurality of signals occur simultaneously, WiFi agreement (CSMA/CD) typically avoids conflict.

Thus, those skilled in the art is with clear, if any potential possible operation situation that may cause fault in the generation said circumstances, amplifier 1212 will correctly transmit signal and not have fault to occur.

According to another embodiment of present principles, two-way amplifier 1200 is suitable for the communication network based on cable newly developed.Yet, in such embodiments, when with technology newly developed, such as MOCA or other coaxial cable data communication system (for example, advanced coaxial cable data transmit (ADOC)), when being applied to current ready-made CATV feeder line (feedline) network, how there is the obstacle of bypass CATV trunk amplifier.

Can bring minimum insertion loss (for example, in＜1dB) situation, the two-way amplifier 1212 of present principles easily to be placed in parallel with the CATV trunk amplifier for the TV signal.Figure 14 shows two-way amplifier 1212 exemplary in parallel with CATV trunk amplifier 1,410 1400.Power splitter 1406 receives TV signal 1404 and utilizes DOCAP 1124 to receive DOCA signal 1402, and exports each root cable branch 1408a-1408d.Every cable branch 1408 will have CATV trunk amplifier 1410 at certain point.For exemplary purpose, show cable branch 1408d and have CATV trunk amplifier 1410.

In this configuration, two-way amplifier 1212 provides suitable gain compensation to two-way ADOC signal, and (for example, 26-30dB), itself and CATV trunk amplifier are to the compensation of TV signal (for example, 26dB) identical (perhaps basic identical).This gain compensation can compensate for example path loss.Those skilled in the art will recognize and use filter (for example, frequency band splitter) in order to separate the TV signal from the ADOC signal.Like this, in one embodiment, will arrange a filter or a plurality of filter at input and the output of CATV trunk amplifier 1410 and two-way amplifier 1212.In this pattern, described amplifier can be used for tdd mode and will meet current WiFi and the WiMax system, especially based on the MOCA system of cable.

Figure 15 shows the method 1500 according to the embodiment of present principles.Initially, monitor the appearance (1502) of up link or down link signal.When only down link signal being detected, the two-way amplifier in the two-way amplifier circuit is switched to delivery status (1504) from accepting state.The method also comprises (as shown in Figure 16) following steps: when only uplink signal being detected (1506), and (1508) maintain accepting state with two-way amplifier when uplink signal both not detected and also down link signal do not detected.As discussed above, apply pre-bias voltage by the non-inverting input to the interior voltage comparator 1208 of two-way amplifier circuit 1200 and carry out keeping accepting state.

Can implement embodiment described here with for example method or processing, equipment or software program.Even (for example, discussing as just method) only is discussed in the context of the embodiment of single form, the feature of the embodiment that also can implement to discuss with other form (for example, equipment or program).Can come facilities and equipments with for example suitable hardware, software and firmware.Can for example implement described method in following equipment, all processors that for example is often referred in this way for processing unit of this equipment for example comprise computer, microprocessor, integrated circuit or programmable logic device.Processing unit also comprises communicator, such as, for example, computer, cell phone, portable/personal digital assistant (" PDA ") and convenient other device that carries out information communication between the end user.

The embodiment of various processing described here and feature can be embodied in various equipment or application (particularly, for example, transmitting and receive equipment or the application that is associated with data).The example of equipment comprises video encoder, Video Decoder, Video Codec, the webserver, set-top box, laptop computer, personal computer and other communicator.As should be clearly, described equipment can be mobile and even be installed in moving vehicle.

In addition, can implement described method by the instruction of being carried out by processor, and such instruction can be stored on the readable medium of processor, such as, for example integrated circuit, software carrier or other storage device (such as, for example hard disk, compact disk, random access memory (" RAM ") or read-only memory (" ROM ")).Described instruction can be formed on the application program of tangible embodiment on the readable medium of processor.As should be clearly, processor can comprise having the processor readable medium that for example is used for carrying out the instruction of processing.

As for those skilled in the art with obvious, embodiment can also produce formatted signal with the carrying information that for example can be stored or transmit.Described information can comprise, for example is used for the instruction of manner of execution or the data that produced by one of described embodiment.Such signal can be formatted as electromagnetic wave for example (for example, using the radio frequency part of frequency spectrum) or be formatted as baseband signal.The stream modulated carrier that described format can comprise encoded data stream for example, the data flow after coding is carried out packetizing (packetize) and utilized packetizing.The information of signaling bearer can be analog or digital information for example.As is known, can transmit signal by various wired or Radio Link.

A large amount of embodiments has been described.However, it should be understood that and to carry out various modifications.The element that for example, can make up, replenish, revise or remove different embodiments produces other embodiment.In addition, it should be appreciated by those skilled in the art that, other structure and processing can replace those disclosed structures and processing and consequent embodiment and will with disclosed embodiment in essentially identical at least (a plurality of) mode, carry out essentially identical at least (a plurality of) function and realize essentially identical at least (a plurality of) result.Correspondingly, these and other embodiment is that the application is contemplated and within the scope of the appended claims.

Claims (21)

1. An amplifier circuit comprising: a bi-directional power amplifier unit (1212) having a bypass mode and for amplifying signals having a first direction and amplifying signals having a direction opposite to the first direction; a bi-directional power detector unit (1202-1204), coupled to the access point side of the bi-directional power amplifier unit to (1) detect a signal having a first direction before it is amplified by the bi-directional power amplifier unit the power of the signal in one direction, and output the first detection signal at the first output terminal, and (2) detect the power of the signal with the opposite direction after the signal with the opposite direction is amplified by the bidirectional power amplifier unit, and outputting a second detection signal at the second output terminal; a switch in communication with the bidirectional power amplifier unit for switching the bidirectional power amplifier unit between a receive state and a transmit state, wherein the receive state is a state in which the bidirectional power amplifier unit amplifies and transmits an uplink signal state, the transmission state is a state in which the bidirectional power amplifier unit amplifies and transmits a downlink signal; and a voltage comparator having an inverting input connected to the first output of the bidirectional power detector unit and a non-inverting input connected to the second output of the bidirectional power detector unit, and connected to output of the switch. 2. The amplifier circuit of claim 1 , wherein the bidirectional power The detector unit is coupled to the bidirectional power amplifier unit. 3. The amplifier circuit of claim 1, further comprising a bias voltage circuit for providing a pre-bias voltage to the non-inverting input of the voltage comparator. 4. The amplifier circuit as claimed in claim 1 , wherein said bidirectional power detector unit comprises a first directional coupler for detecting transmit power, i.e. uplink power, and a first directional coupler for detecting received power, i.e. downlink power. Second directional coupler. 5. The amplifier circuit of claim 4, wherein the bidirectional power detector unit further comprises a first RF power detector and a second RF power detector, wherein the first RF power detector and the second RF power detector Each of these is used to convert RF power to DC voltage. 6. The amplifier circuit of claim 1 , wherein the voltage comparator causes the switch to switch the bidirectional power amplifier unit to remain in the receiving state. 7. The amplifier circuit of claim 1, wherein the voltage comparator causes the switch to maintain the bi-directional power amplifier unit in a receive state upon detection of a transmit power (uplink power) signal. 8. The amplifier circuit of claim 1, wherein the voltage comparator causes the switch to flip the bi-directional power amplifier unit to a transmit state upon detection of received power (downlink power signal). 9. The amplifier circuit of claim 1, wherein the bidirectional power amplifier unit is arranged between an access point device and a modem. 10. The amplifier circuit of claim 1, wherein the bidirectional power amplifier unit is arranged between a splitter and a modem. 11. An amplifier circuit comprising: a directional coupler (1202) having an input and an output; a bi-directional power amplifier (1212) having a bypass mode and having an input coupled to an output of the directional coupler and an output for connection to a modem, wherein the input of the directional coupler is for connection to an access point, and the directional coupler is connected to the access point side of the bidirectional power amplifier; a power detector (1204), connected to the directional coupler, and used to detect downlink power and output a first detection signal at a first output end, and detect uplink power and output a second detection signal at a second output end detection signal; A voltage comparator (1208), having an inverting input terminal and a non-inverting input terminal, the inverting input terminal and the non-inverting input terminal are respectively connected to the first output terminal and the second output terminal of the power detector; a voltage divider network (1206) connected to the non-inverting input of the voltage comparator and used to provide a pre-biased voltage to the voltage comparator; and A switch (1210) connected to the voltage comparator and the bi-directional power amplifier, the switch for changing the operational state of the bi-directional power amplifier in response to a signal received from the voltage comparator. 12. The amplifier circuit of claim 11, wherein the directional coupler further comprises two directional couplers, one for detecting uplink signals and the other for detecting downlink signals. 13. The amplifier circuit of claim 11, wherein the power detector comprises two RF power detectors for converting an RF signal to a DC voltage. 14. The amplifier circuit of claim 11 , wherein the switch comprises a single pole double throw switch configured to switch between active mode and bypass in response to a detected uplink signal and/or downlink signal. switch the bidirectional power amplifier between road modes. 15. The amplifier circuit of claim 11 , wherein said directional coupler, said bidirectional power amplifier, said power detector, said voltage comparator, and said switch all comprise a high speed operational response such that said amplifier The overall operational response time of the circuit is less than 300ns. 16. A method of controlling the state of a bidirectional amplifier, the method comprising: The access point side of the bi-directional amplifier with bypass mode within the bi-directional amplifier circuit monitors the presence of an uplink signal or a downlink signal and detects the power of the uplink signal present to obtain a second power voltage or the presence of the power of the downlink signal to obtain a first power voltage; and comparing the first power voltage and the pre-bias voltage by a voltage comparator when only downlink signals are present; and When only downlink signals are present and the first power voltage is greater than the pre-bias voltage, the bi-directional amplifier is switched to a transmit state, wherein the transmit state is a state in which the bi-directional amplifier amplifies and transmits downlink signals. 17. The method of claim 16, further comprising: maintaining a bidirectional amplifier within the bidirectional amplifier circuit in a receive state in the presence of an uplink signal, wherein the receive state is a state in which the bidirectional amplifier amplifies and transmits an uplink signal; and A bidirectional amplifier within the bidirectional amplifier circuit is maintained in a receiving state when no uplink signal or downlink signal is present. 18. The method of claim 16, wherein the monitoring is performed by a directional coupler located on the access point side of the bidirectional amplifier. 19. The method of claim 17, wherein the maintaining step further comprises: applying a pre-bias voltage to a non-inverting input of a voltage comparator within the bidirectional amplifier circuit. 20. An amplifier circuit for use with an existing CATV system, wherein said CATV system comprises one or more cable branches, each cable branch having at least one CATV trunk amplifier, said amplifier circuit comprising: a bi-directional power amplifier unit (1212), having a bypass mode, arranged in parallel with each CATV trunk amplifier on the cable breakout, and for amplifying signals having a first direction and amplifying signals having a direction opposite to the first direction , the bidirectional power amplifier unit enables the path of the coaxial cable data transfer protocol to be able to operate on said CATV system; a bi-directional power detector unit (1202-1204), coupled to the access point side of the bi-directional power amplifier unit to (1) detect a signal having a first direction before it is amplified by the bi-directional power amplifier unit the power of the signal in one direction, and output the first detection signal at the first output terminal, and (2) detect the power of the signal with the opposite direction after the signal with the opposite direction is amplified by the bidirectional power amplifier unit, and outputting a second detection signal at the second output terminal; a switch in communication with the bidirectional power amplifier unit for controlling the bidirectional power amplifier unit to amplify a signal having a first direction or to amplify a signal having a second direction; and a voltage comparator having an inverting input connected to the first output of the bidirectional power detector unit and a non-inverting input connected to the second output of the bidirectional power detector unit, and connected to output of the switch. 21. A cable system comprising: at least one power splitter (1406) having at least one input connected to a CATV cable-based television service provider and at least one input connected to a coax data transfer protocol system, said power splitter having At least one cable breakout output; CATV trunk amplifier (1410), connected in series with at least one cable branch; and a bi-directional amplifier circuit (1212) connected in parallel with said at least one cable branch surrounding said CATV trunk amplifier; Wherein, the bidirectional amplifier circuit includes: a directional coupler having an input and an output for detecting the presence of uplink signal transmission or downlink signal transmission; a bidirectional power amplifier unit connected to the detector; and a switch in communication with the detector and the bidirectional power amplifier unit for switching the bidirectional power amplifier unit between a receive state and a transmit state, wherein the receive state is in which the bidirectional power amplifier unit amplifies and transmits uplink a state of a link signal, the transmission state being a state in which a bidirectional power amplifier unit amplifies and transmits a downlink signal; wherein the directional coupler is connected to the access point side of the bidirectional amplifier; a power detector connected to the directional coupler and used to detect downlink power and output a first detection signal at a first output end, and detect uplink power and output a second detection signal at a second output end; as well as a voltage comparator having an inverting input connected to the first output of the power detector and a non-inverting input connected to the second output of the power detector, and an output connected to the switch .

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