CN1011464B - Baseband local area network using ordinary telephone wiring - Google Patents

Abstract

The present invention discloses a local area network (LAN) which can conveniently establish general data communication on a common telephone line. The present invention is composed of a systematic structure and circuit technique. The local area network can be constructed on common telephone lines in a building or among building groups (usually called a CamPus) which are not far away from each other. The implementation of the LAN does not interfere with the audio function of normal telephone lines, and connecting wires do not need to be increased. According to the present invention, the implementation of the local area network needs only three types of hardware functional components: a node unit (NU), an interrupter unit (IU) and a pulse regenerator unit (PRU), wherein the pulse regenerator unit is possibly absent or present according to the size of the network.

Description

Baseband local area network using ordinary telephone wiring

The present invention discloses a kind of low price localized network (LAN) notion and relevant technologies, and these technology can be set up the vague generalization data communications equipment on ordinary telephone wiring.Newspaper has revealed several different variants, and they can make this technology be used widely and can adapt to the difference of installing at phone.Several variants all be with the communication of relative normal audio noiseless and independently mode data communication is added on the existing voice band line.Use those methods of back, same circuit can be used for audio frequency and data communication simultaneously.

Localized network (LAN) is the core of office automation tide.Have many distinct methods to come into the market, and all these networks that have an acceptable attribute of performance of LAN all require transmission medium (no matter it is coaxial cable, twisted-pair cable or fiber optic cables).In vague generalization applied environment (no matter selecting which kind of medium), the installation of transmission medium all expends and inconvenience.Like this, it is very high to use mounted circuit to remove to constitute the cry of a localized network.This is limited to two kinds of possibilities basically, (a) transmission line and, (b) telephone line.Owing to have many practical problems, lose interest in to transmission line being used for the vague generalization lan environment soon.On the other hand, telephone line is a good candidate.It is a kind of resource that grows on trees, and is present in any conceivable place concerning a work station.The resource that telephone wire is still highly underused, no matter the circuit with regard to not being used, still the frequency bandwidth of the circuit of use is not always the case.

For many years, telephone line is used for that the standard method of data communication is, and to continue will be to utilize modulator-demodulator carrier wave to be carried out the technology of modulation.Some nearer technology uses have carrier wave and fully are higher than the short haul modem of audiorange and allow to carry out simultaneously audio frequency and data communication on same circuit.The subject matter of these technology is them concerning the LAN type is used: (a) have very limited bandwidth, (b) require the electronic unit quite expend, and (c) be the method for point-to-point basically, this and the desirable method with the ability of interkniting of LAN are opposite.On the other hand, disclosed technology can make to be had any access protocal and particularly is well suited for CSMA/CD(carrier wave check, has the multiple access of collision detection) complete vague generalization LAN architecture become feasible.As the data baseband system, it provides very wide bandwidth and while price to be significantly less than modulation-demodulation technique.Because it is a baseband system, concerning disclosed technology, the length of the communication link of permission will be more restricted than the carrier wave person with modulation, and foreseeable installing will be fully enough but it is to any reality.For example, in the time of 300 kilo hertzs, the link that uses its length quite to surpass 1000 feet (305 meters) should be out of question.With respect to the error rate that allows, use anti-error communications protocol in the information permission of LAM application distribution resource, the result, and do not require extremely low error rate.

Goal of the invention of the present invention be to provide a kind of cheaply, utilize the existing telephone line to carry out the localized network of speech and data communication simultaneously.

Goal of the invention of the present invention is to realize by following technical solution.Wherein and the closely-related technical characterictic of theme of the present invention be: a kind of localized network of between the node more than two or two, communicating of being used for, each node comprises and is used to produce with the telephone set of received audio signal and is used to produce work station with receiving digital signals that described network comprises;

The telephone exchange machine that is used for exchange of audio signals;

The data bus means that is used for transmission of digital signals;

Wherein each node also comprises:

The telephone wire device;

Be used for coupling audio signal between described telephone set and described telephone wire device but first device of the digital signal that is not coupled;

Be used between described work station and described telephone wire device the coupling digital signal but second of the coupling audio signal device;

The invention is characterized in that described node also comprises;

Be used for coupling audio signal between described exchange apparatus and described telephone wire device but the 3rd device of the digital signal that is not coupled;

Be used between described data bus means and described telephone wire device the coupling digital signal but the 4th device of coupling audio signal not;

Described data-signal communication and described audio signal communication can work and not disturb mutually simultaneously.

In order to understand the present invention better, please refer to of the present invention being described in detail and relevant accompanying drawing, wherein:

Fig. 1 is the principle of the invention block diagram of simplifying;

Fig. 2 is according to four lines of the principle of the existing invention block diagram of data (DO) localized networks (LAN) only;

Fig. 3 is the only block diagrams of data (DO) localized networks (LAN) of two lines;

Fig. 4 is the localized network block diagram with audio signal path and data path;

Fig. 5 is the block diagram in conjunction with workstation configuration of the present invention;

Fig. 6 is a circuit diagram of realizing the repeater units bus for large scale network;

Fig. 7 a and 7b are respectively the functional block diagrams of half-duplex (transmission) line (road) and receiver/drive circuit;

Fig. 8 a and 8b are the vague generalization system block diagrams of typical LAN system;

Fig. 9 is the example of single worker/single worker's configuration of repeater units (RU);

Figure 10 is the example of the single worker/half-duplex configuration of repeater units (RU);

Figure 11 is the example of half-duplex/single worker's configuration of repeater units (RU);

Figure 12 is the example of the half-duplex/half-duplex configuration of repeater units (RU);

Figure 13 is an example of half-duplex/single worker's bidirectional drive;

Figure 14 is the block diagram with LAN of packeting controller;

Figure 15 is-block diagram of LAN, and it has multistation (passage) router and has total service station node toward the high performance network path;

Figure 16 is the example of half-duplex/half-duplex bidirectional driver; And

Figure 17 is the example that is used for the impulse regenerator (PRU) of half pair of RU pseudo-bus node expansion.

United States Patent (USP) 4063220(1977.12.3), " the multiple spot data communication system with collision detection " described the localized network system of well-known Ethernet by name." can carry out the equipment of communication between two or more data processing stations, it comprises communication cable, and this cable is arranged on the son field that comprises connecting box in the summary disclosure of this patent.What link each connecting box is a receiver transmitter, and its opposing party connects to relevant interface level.In addition, each receiver transmitter includes the transmitter and the receiver of usefulness, a door, and it equates comparing and indicate whether from the data of interface level and the data on cable.If unequal, promptly indicate to accept to have between transmitter and the cable and conflict, by relevant transmitter part.”

When the Ethernet system protocol became industrial standard rapidly, it required the very wide telecommunication cable of bandwidth to transfer of data.It is not difficult in new office or other type structures this cable being installed, and expends very much but just become when installing in existing structure.Utilize the existing telephone line of building, on the distribution communication network, accomplish not have line switching to link, become a very attractive solution of unresolved mistake in the past.

From the topology angle, overall network is a kind of star like arrangement, and it has the switch/processing capacity in the centralization of maincenter place.Very big bundle conductor (telephone cable) is the radial building of linking, and links the telephone cabinet of building, receives every telephone set by these telephone cabinets again.Like this, all there is one twisted-pair cable (generally being two twisted-pair cables) to receive telephone cabinet, connects to PBX by telephone cabinet again from every telephone set.

The present invention is made up of architecture and circuit technology, and it can be in a building or at a distance of not far building, often be called " campus ", between ordinary telephone line on build up localized network (LAN).And the LAN that is realized the not normal audio function of interfering phone circuit does not need to set up additional circuit.

Fig. 1 is the functional-block diagram of simplification of the present invention, and it illustrates three stations or the node that is connected to that a common data bus and telephone exchange get on.Each node telephone wire of comprising a telephone set, a work station or a terminal and being used for telephone set and terminal are coupled to data/address bus and telephone exchange wherein.A low pass filter is connected between telephone set and the telephone wire, and second low pass filter is connected between telephone wire and the telephone exchange.Similarly, a high pass filter is connected between terminal and the telephone wire, and second high pass filter is connected between telephone wire and the data/address bus.By above-mentioned setting, just make can not occur disturbing along between data/address bus transmission of data signals and the voice signal by the telephone exchange transmission.

Characteristics more of the present invention are:

Use low price baseband signal tranmission techniques;

Real LAN connectivity is arranged, that is logic to virtually connect knot continuous with respect to switching circuit; On function, the user seems to be linked to bus;

Allow any access protocal, i.e. CSMA, CSMA/CD, token Passing etc.,

There are four kinds of variants to be defined;

Use existing telephone line, make it not need other laying-out (cable) to set up the LAN system like this;

Of great use communication bandwidth can be provided, and (typical range is 300 kilo hertzs to 500 kilo hertzs.）

For the present invention, four kinds of basic variants are to data stack audio frequency (DOV) or only pass four lines of data (DO) technology or the combination of two ray modes.

Realize that according to the present invention a localized network LAN only requires the iron-cloth energy parts (according to the concrete suitable amount that needs of using) of three kinds of patterns: (a) node unit (NU), (b) TU Trunk Unit (RU), and (c) depend on the network size size, have pulse regneration unit (PRU).They only come into question together at block diagram functional level and some physics realization details in a word bright.The detailed description of back will be studied the details of these functions.

Typical case is that " telephone cabinet " in the building all is placed in building everywhere.They need and the interconnection of service telephone line in building cover thing localized areas.Building in the cover thing also, some circuit can interconnect between telephone cabinet.

About the whole system figure of the effect of these functions and the architecture of lan technology can be found out from only data (DO) configuration of Fig. 2 and Fig. 3.In detail on this one-level of block diagram, should not express telephone set and be connected on the NU unique not being both of data stack sound equipment.

In Fig. 2, RU55 and PRU56 are placed in the telephone cabinet as can be seen, and NU53 is placed on each work station, provide the function declaration of each block diagram element below, the function declaration of NU and RU changes what are relevant with that LAN variant (i.e. two lines or four lines, and be DOV or DO).

Two lines only data (DO) variants (half-duplex) so realize that method is with idle passive telephone line or uses two not circuits of moving most of telephone sets on the active circuit to of utilization.

Four line DO variants (every couple of single worker) are suitable for realizing on passive (phone) circuit of free time most.

Four lines or two line data audio frequency stack (DOV) variant can be realized on active circuit.In four line DOV variants (every couple of single worker), active tone frequency channel wire is to reaching the non-audio line to all using.In two line DOV variants (half-duplex), use tone frequency channel wire right.

In consolidated network was laid, it also was possible that DO and DOV technical combinations are got up.For example, two data communication channels (two line DO and two line DOV) can be realized moving on four lines of a telephone set.Audio frequency is to realizing as two line DOV, and non-audio is to as two line DO.Certainly, the design of RU needs to adapt to the interface of these two kinds of patterns.

In DOV realized, the present invention was added to the Data Base band signal on the audio signal of telephone network.Finish this point and be fully and for the use of carrying out the voice communication telephone system independently irrelevant, and allow station A to carry out voice communication with station B simultaneously and and station C carry out data communication (or large quantities of other stations of conduct mailing on LAN or information broadcast processing).Data and audio path are irrelevant mutually, and particularly data path does not relate to central PBX maincenter (see figure 4).On topology and function, audio network keeps star structure, and data network seems that physically the star topology is arranged, but its function is a bus.Can be described as " star bus " like this.Line link from the telephone cabinet to the telephone set is called the radiation branch road, and the function of the user terminal of radiation branch road is called as work station node (no matter it is the server of phone, personal computer or certain pattern).

The node unit

Referring to Fig. 2, each work station 51 of repeatedly kicking in the network all needs a NU53 in the work station position.If the phone of active (or " effectively ") is arranged in the place near network, and this NU can be inserted between top connection of RJ-11 wall and the telephone set.Also has a suitable interface connector to be attached to the equipment of network.NU will carry out following function at least:

The line drive that supplies baseband signal to use;

The line receiver that supplies baseband signal to use;

The termination that provides for baseband signal;

The low-frequency data signal energy is filtered so that do not make it enter telephone line;

Filter the high-frequency energy that is added on the line, in DOV carries out, make it not enter telephone set;

Filter audio band and signal energy so that DOV does not make it to enter the data communication circuit in carrying out;

For the main frame of linking on the network provides communication interface.

In addition, can make NU do better, make it to finish many tasks, as if packet encoder/decoding, matching addresses, collision detection, error management etc.Otherwise primary processor need be carried out these tasks, but this decision and the present invention are irrelevant, and the present invention only requires defined ability minimum.

Repeater units

In Fig. 2, RU55 be one and work input (as, 16 may be custom input number) relevant multichannel (or " multistation ") device.I/O channel interface to each network equipment will have two lines or four lines, depend on employed be two ray modes or four ray modes (for each line to, two lines are half-duplexs, four lines are single workers).

Except the I/O interface to network equipment, RU also has an inner pseudo-bus node, and this node has external bus node expansion (BNE) interface, so that and other chainings of RU (usually through a PRU).The same with the I/O interface, the BNE interface may be that two line half-duplexs or four line list frocks are put.These will be illustrated together with Fig. 5.

See Fig. 2, repeater units 55 is placed in the phone distribution case, and this case also contains from the node that will be access in network the next telephone wire of telephone set that links being arranged.Just telephone wire is linked main line bundle (cable) herein, by this main line bundle phone is connected to central pbx (private branch line switch) at last.RU comprises a small amount of circuit and power demand (supply socket is arranged in the telephone cabinet under the normal condition).RU is mute fully, only play a part some simple electric on.It will be by more careful description in the technical descriptioon below.By the RU in the telephone cabinet, the line of relevant with the work station that enters network (coming work station since then) is pulled down from terminating set (it is connected to this line in the trunk line that moves towards PBX), receive connector like the category of RU.Then jumper is connected between another group connector of the original end points of this terminating set and RU.Like this, concerning each network connections, the RU circuit is inserted in the personal call line and leads between the distributing line contact of PBX.RU can design to such an extent that can handle its required large volumes of channels (for example, can be the some patterns that have 8,16 or 32 channels) to different application under the normal condition.And for extension of network, some RU can be connected to each other.Increasing NU all is repetition with the step that is connected to RU to the node that each is increased on the network.When surpassing existing RU capacity, just increase the RU that adds.The RU that is placed in the different casees can interlink with existing cabling in each case, makes network be not restricted to the work station of only being served by a common bin.(see figure 10).

The function of RU is as follows:

Provide line drive/receiver ability to the I/O interface;

Provide line drive/receiver ability to bus node expansion BNE interface;

When it when one of its incoming line receives a signal, its repeat (repercussion) identical signal return to whole I/O lines that move towards the outside (except circuit in two ray modes just by the situation of being sent words person to use, when sending words, just can not listen) and BNE interfaces;

Filter the low-frequency data signal energy, make it to enter telephone wire;

Filter the high-frequency data signal energy that is added on the line, make it to arrive PBX;

For data-signal provides termination.

The impulse regenerator unit

Referring to Fig. 2, PRU56 is used for the BNE bus, as need be to data-signal shaping and more regularly again.

System description

The invention that realizes this disclosure requires will use at least top said two hardware, and in each a node unit, work station node place (NU) and a repeater units (RU), the latter is placed in the phone distribution case.Phone distribution case is placed within the building equipment tactfully, the distance that is typically any telephone set is all within 200 feet, design details to NU and RU will be with different some difference of specific system's variant, but these difference are not main, and the internal work situation of these functions will and describe in detail with represented accompanying drawing and be discussed.In this discusses, system's variant is only discussed in the black box one-level.

Four lines, only data (DO)-basic conception can be by illustrating with reference to figure 2, and each functional part that links the vague generalization network configuration of many work stations (work station 51a is to 51z) illustrates out.Each work station has node unit (NU) 53a who links to 53z and express repeater units (NU) in the distribution case.A plurality of RU55 on demand can interconnect in single distribution case or between the distribution case.From electric consideration, in fact there is not any restriction, because the RU in each radiation branch is a termination and isolated.Each circuit between NU53 and RU55 be a twisted-pair cable 57a to 57n, they are operated in simplex mode.RU55 makes mute on function, and transmits the content that it is heard at whole output lines (arrow leaves RU) on incoming line (arrow points RU) simply.Like this, when a work station 51a send when words by sending line 57a to network, all other work station can be heard by its associated reception line.This likes linear bus well from function, though it likes a star from the topology angle.Certainly, can be any desirable access protocal (as Token Passing, CSMA, CSMA/CD).

The idle passive telephone wire in each building almost that use is deposited can be realized only data method of this four lines.In this case, a network being installed needs approximately and carries out phone and expand the identical amount of labour (amount of labour of phone expansion equals to lay the amount of labour of network node).

Two lines, only the block diagram of this technology of data (DO)-in Fig. 3 is similar to Fig. 2 very much, is in NU63a between 63z and the RU65 except a pair of half-duplex line is arranged.As a result, one works as work station 61a begins to send words to 61z on line, and it can not listen and detect conflict.This technology is limited to does not have CSMA access method or the Token passing access method that conflict detects.This also requires some special circuit technology, can be installed on a pair of in four lines but advantage is it, and it leads to each telephone set usually.In most of the cases, it is fully possible removing to set up LAN with the existing phone that has been delivered for use.

Four lines, stacked data add audio frequency (DOV)-be the four line DOV schemes of describing disclosed system, refer again to Fig. 2 here.On the details of block diagram, unique difference is that a telephone set is received each NU(and seen Fig. 4).This technology is added to a digital baseband channel on the analoging sound channel.These two channels are irrelevant each other fully, and can carry out work to the difference station simultaneously.The key technology that is published in this method is the technology (signal and communication, circuit and filtering technique) of the suitable hardware system of exploitation, and these technology provide enough isolation to go to prevent that energy from being leaked into voice band line and being reduced the voice communication performance by digital communication.

Two lines, stacked data add audio frequency (DOV)-two line DOV method except the telephone set that adds NU, and are very similar with Fig. 3 functional block diagram those shown.Also have, as two line DO methods, the link between NU and the RU is half-duplex, so its access protocal will be CSMA or Taken passing.

To provide below more complicated DOV(stacked data will be added audio frequency) technical descriptioon of method.DOV and DO(be data only) difference between the method is very simple, and will discusses in following.

For the beginning technical discussion, refer again to Fig. 4, express the path of audio frequency 10 and data 12 there.If NU18,20 and RU22 between line not only comprise audio frequency but also comprise baseband digital data to 14,16 one, with one group of suitable filter digital signal is filtered from following scope, this scope is to exceed RU22 in one direction, exceeds RU18 on other direction, 20.Each online end carries out suitable termination to baseband digital signal, guarantees not have reflection problems.For the audio-frequency function of telephone system, these whole circuit are sightless.Be shown in the link 14 of Fig. 4,16(is referred to as the radiation branch) in fact by one of in the telephone cable or two lines to forming (depend on is with two lines or four line schemes).If four ray modes, every pair is operated in simplex mode, the viewpoint of slave station node 18,20, and a pair of is to send line, when wanting to use it when network send words, another utilizes it to make the station can listen to the activity of network to being to receive line always.It is right that each node 18 has two identical lines on the network, and go to intercept the activity of network by its reception line.Attempt is used more than a station 24,26 and is gone to transmit at one time and will produce conflict, and all stations of this conflict all can detect.Like this, though from this network of topology angle as if a star, its behavior is a linear bus.

The transmission reception line of single station node and the more detailed functional block diagram level research of relevant circuit technology are shown in Fig. 5.Fig. 5 discloses one four line list worker/half-duplex system, and this system comprises the work station 51a at top, and node unit 53a and repeater units 55(are shown in Fig. 2).Can be clear that very much the function of RU22 now.The characteristics of a key are the internal bus nodes, and it is by arbitrary 24 drivings in station of thinking accesses network.It still is the common input end of whole drivers, and these driver drives receive the line signal and return those stations.This node can be connected between the repeater units simply to remove to expand this network.It is right that bus node expansion (BNE) is expressed as single line.As a result, signal must in careless which direction can communicate along this bus.This is a half-duplex bus, but it also can be realized by simplex mode with four lines.To the different choice back of realizing the BNE bus method discussion more carefully will be arranged.Other function of RU is: a) isolate and cushion various transmissions, receive line, b) provide termination to data-signal, c) filter digital signal from these lines, make it not lead to telephone cabinet.The function of NU as shown in FIG. 5 provides: a), b), c) digital signal end connect to receiving (line) right detection interface to sending (line) right interface, and d) filter low frequency energy from digital signal, make it not enter telephone line.Because the length of node unit NU and repeater units RU top-stitching (little big irrelevant with network rule groove) is very limited, so the electric circumstance of data-signal is fine.Concerning great majority were used, these links did not surpass 200 feet persons.

Still with reference to figure 5, can find out has three filter functions, uses Filter1(201), Filter2(203), and Filter3(205) distinguish.In fact because these filter design are to deliver registration according to the key technology in the stack audio frequency method, will discuss tout court them.

Filter1(201) be high pass filter, its main task provides in enough decay of voiced band frequency so that do not enter voicefrequency circuit from the low frequency energy of digital channel.Though digital data signal is higher than audio band well at about about 300 kilo hertzs,, the low frequency monkey chatter is low PRF(pulse repetition frequency) result that occurs.For example, the folk prescription wave impulse is at Sin(x)/continuous frequency spectrum is arranged within the x envelope.

Filter2(203) holding wire termination and be a low pass filter to digital data.Its groundwork is to avoid entering voicefrequency circuit by the high-frequency energy that digital communication channel produces.If it also avoids line end to be caused digital circuit destroyed by short circuit etc.

Filter3(205) be used for reading (receiver) function on the line, and the same with F1 also be a high pass filter, and to make F1 under many circumstances identical with F3 be possible.But in this explanation,, still they are distinguished respectively for vague generalization rises.Requirement to F3 provides enough sufficient data-signal and does not cause load to voicefrequency circuit.

Very urgent performance objective may require in these two filters one or be active entirely; But in a DOV pilot system, it is established and tests, and filter 1 is single capacitor, and filter 2 is one-level inductance capacitances.Design with this, the quality of voicefrequency circuit does not have the distortion that can check out, but design must guarantee to obey FCC Part68(FCC: U.S. FCC standard person).

Be in operation, phone 28 can be used, and is irrelevant with the numerical data aspect of system.That is telephone set 28 is received normal output telephone wire, these output lines move towards telephone cabinet and subsequently cable to another telephone cabinet and/or central pbx.But as mentioned above, filter is comprised, so that make voice data not enter digital data signal and opposite.

In numerical data work, work station 24(personal computer, terminal etc.) be coupled to amplifier 34 and 36 through connector circuit 25.The circuit element that box 25 comprises standard removes to mate the impedance and the level of various personal computers and terminal, so that consistent with those amplifiers in node unit 18.Can arrive amplifier 34 by connector circuit 25 from the signal of work station 24.Amplifier 34 is coupled to single line 206 and single line 208 in this simplex system to digital data signal.Repeater units 22 in telephone cabinet, digital data signal are exaggerated device 44 and amplify once more and deliver to bus node 50.In method of reseptance, the signal on the bus node is amplified by amplifier 46 so that digital data signal is added on single line 210 and the single line 212.These signals are received amplification and are delivered to work station 24 through connector circuit 25 by amplifier 36.With top said the same, since above-mentioned F1,2 and 3 effect, and voiceband data signal and digital data signal are that its opposing party's system repels.

Fig. 6 expresses two repeater units with four line list worker pseudo-bus nodes, but can utilize its difference (these difference may be distances, telephone cabinet) that they are separated.Say that schematically output amplifier 44 is sent to Bus Wire dotted line 310,312 to its output, data-signal is sent to another work station.Signal makes progress away, and the top branch road of process bus node lead-in wire is to another branch road that returns another work station for the guiding data-signal, as the signal of amplifier 46 receptions.But, if being directed to the work station at this place, numerical data is not coupled same TU Trunk Unit, may wish so and/or typical industrial impulse regenerator 303 of needs use.This impulse regenerator 303 must have terminal impedance 316, removes to be in harmony these lines of local termination by the characteristic impedance of these lines itself, and this impulse regenerator also comprises suitable gain and return line 318,320 is sent to next repeater units to signal to be in harmony local.

For the explanation of this point, mainly at four line list worker technology.Two line technologies in the half-duplex direction also can be realized.But, two wire system use a pair of line by half-duplex mode work with some distinct line road techniques of requirement.Desired special technique relates to line drive/acceptor circuit.Fig. 7 a is at the right functional block diagram of the transceiver at each station of half-duplex line.Difficulty appears at the repeater units end, and wherein driven same bus node is detected, returns so that be driven along same line.The way that solves is that the transceiver design in RU is become like this: they will lose efficacy a period of time, if they were driven at output before input.Utilize this characteristic, transceiver is to only driving in a direction at one time.In the time window of appointment, amplifier get clogged a period of time at both direction (overtime) appears causing in signal simultaneously.For removing to obtain RU bus node more than one work station by the state of conflict access method also is possible.No matter under which kind of situation, these incidents are handled by procotol.A simplified block diagram is shown in Fig. 7 b, and it expresses how to reach this characteristic.Time-delay guarantees that reverse driven lost efficacy before forward driver begins to send words.

In Fig. 7 b, the data-signal of coming in from work station can be added to the input of delay circuit 602 simultaneously, and also is added to monostable 606 and 611 triggering input.Be triggered when monostable 606, its output makes and monostable 608 lost efficacy (if monostable 608 be not triggered) in the timeout interval of appointment.Similarly, when monostable 611 were triggered, its output was lost efficacy amplifier 610 in same timeout interval.This timeout interval by sampling become what greater than the bit time so that make during data are transmitted, two monostable 606 and 611 keep the triggering state continuously.One works as the data transmission stops, and monostable 606 and 611 will be reset after timeout interval, will discharge monostable 608 one-tenth like this and wait for the triggering states, and amplifier 610 become effective status.The signal of coming in is delayed time, and the signal of coming in that its time-delay length is enough to allow reciprocal amplifier 610 to be appeared at and acts on earlier on monostable 611 before amplifier 610 inputs is forbidden.The data-signal of being delayed time can be added to amplifier 610 at last, but it can not be exaggerated and send, because it is received from rightabout and be under an embargo through monostable 611 the signal of coming in owing to detecting.Certainly, if monostable 611 signals that do not detect into, numerical data is added to amplifier 610 from delay circuit 609 and can be sent by circuit.Respectively the output of amplifier 604 and 610 is detected as the numerical data of coming in for fear of monostable 608 and 611, the output from monostable 606 or 612 can forbid that the inhibit signal of monostable 608 or 611 transmissions its oneself is to amplifier 604 or 610.Be shown in amplifier circuit 44 and 46 among Fig. 6 A and comprise circuit among Fig. 6 B, this circuit allows data-signal at forward with oppositely be sent out, but is not at one time.

The LAN architecture

With the object lesson of research Fig. 8, to provide detailed description to defined LAN architecture notion among the present invention.

In this LAN architecture example, a lan topology is illustrated, wherein, (a) comprise three Different L AN#1, #2 and #3 (b) relate to four telephone cabinets and distribute rack 1 to 4, and having linked LAN by an intelligent routing unit 701, this routing unit provides address smoothing to prevent unwanted communication communication on each LAN.To forming, in the case, it is operated in half-duplex mode to the represented line that is connected in the RU pseudo-bus node extended channel between the RU, or is made up of 2 pairs of lines by a line, and at this moment every pair of line is operated in simplex mode.

From distribution rack #1, it comprises 5 RU, and wherein three mutual bindings are used for LAN#1, and LAN#2 and LAN#3 are respectively with one.The line of shown those bridging work stations NU to RU comprise a line to or two lines right, the previous case works in half-duplex mode, the back every pair of one situation be operated in simplex mode.To each LAN, expressed RU pseudo-bus node and extended to distribution rack #2, and (in the situation of LAN#3) arrives distribution rack #4(because the there does not have direct line to move towards #4 from distribution rack #1) from distribution rack #1.

Intelligence routing unit 701 is placed among the distribution rack #2, and all the pseudo-bus node of LAN extension must move towards the rack #2 that distributes, if it is linked to other LAN.Intelligence routing unit 701 can be the program control electronic computer, certainly, or a hardware circuit.

It is also noted that, in distribution rack #2, for the pseudo-bus node link distribution rack #2 of the RU of LAN#2 expansion to distribution rack #3, need an impulse regenerator (also seeing Fig. 6).

Repeater units

As previously mentioned, the essential element of LAN notion is repeater units (RU).On function, RU can be described as being the mute repeater of a multichannel, and (for example, Fig. 5) it has I/O channel separately, and (for example, Fig. 3) it has the I/O passage of associating to two line half-duplex modes to four line simplex mode types.When a signal is input to RU, it is repercussion, and in each output channel output signal, and also carry out repercussion for being linked to other RU at RU pseudo-bus node extended channel.RU can be designed to have the I/O passage of different numbers, if wish to deacclimatize different application need (as 16,24,32).

For RU, have four kinds of basic variations, this depends on: the pattern and the b of (a) I/O (I/O) line) pattern (they will be named by the pattern of communication on I/O passage and pseudo-bus node extended channel, as single worker/single worker) that realizes of pseudo-bus node.These variation diagrams are shown in Fig. 9 (single worker/single worker), Figure 10 (single worker/half-duplex), Figure 11 (duplex/single worker), and Figure 12 (half-duplex/half-duplex).During beginning, the basic function of RU illustrates that by these block diagrams the circuit details with a specific implementation illustrates subsequently.

Be an inventory of RU key characteristic below, the mark in its brace can find in Fig. 9 to 12:

(a) provide transmission line characteristics resistance termination (RO) to baseband signal;

(b) provide high pass filter (F1) to enter telephone wire to prevent the low frequency signal energy;

(c) provide low pass filter (F2) to scurry PBX to prevent higher frequency signal energy;

(d) comprise an inner pseudo-bus node, it has suitable driving electronics can interconnect RU to produce general lan topology, RU pseudo-bus node to expansion has two kinds of basic selections, the pattern that depends on use is four lines or two lines: (1) pseudo-bus node can be by two holding wires to (Fig. 9 and 11 B1, B1 ' and B2, B2 ') forms, each all is operated in simplex mode, or (2) pseudo-bus node can be by single line to (Figure 10 and 12 B1, B1 ') forms, be operated in half-duplex mode (requiring to use the half-duplex bidirectional driver of Fig. 7);

(e) comprise line receiver unit and driver, they are coupled to telephone wire (being ready to use transformer) and are operated in balanced differential mode (T/R among Figure 12) with exchange way;

(f) may wish also in RU, to add the impulse regenerator function, but in this application, impulse regenerator will be described as a standalone feature that separates.

Use the simplified block diagram of Fig. 9, the input signal that comes from work station node unit (NU) illustrates the working condition of a single worker/single worker RU at input I by telephone wire to being added to RU.Description to Fig. 2 and 5 also may be used on herein above, except the function of RU is expanded internal circuit and the work expressed.Input signal on the line 801 and 803 is added to filter F3 and is input to transformer 805.Filter F3 becomes a high pass filter and can prevent that any audio signal from entering digital data circuit.Any voice data will continue to shift to the right side telephone line extremely subsequently of figure, as if the PBX position.Transmit amplifier 807 amplifier digital data-signals and process transformer 809 are added to line B1 and B1 ' to it.The effect of capacitor 813 and characteristic impedance RO815 is to make circuit termination become its characteristic impedance, in case the stop signal reflection.To be low pass filter unhinderedly pass through with the voice data that allows low frequency filter F2, prevents that the high-frequency digital data from passing through.

B1 and B1 ' receive B2 and B2 ' (see figure 6) at last in this single worker of pseudo-bus node realizes.If signal transmits along B2 and B2 ', be added to reception amplifier 823 through transformer 812 and filter F3.After amplifier 823 amplifications, signal returns to this working end through the filter F3 on the line 827 and 829.

The signal that appears on any input amplifier (807) will drive the bus node relevant with the input of delivering to RU to (B1/B1 ').This signal will be propagated at both direction along B1/B1 ', and still, only amplifier output is linked to B1/B1 ', so to they not effects.Also have, if be used under the situation of single worker's bus node at impulse regenerator, they only pass through in the direction of appointment.Corresponding B1/B1 ' and B2/B ' bus (line to) are joined together between RU, make this signal continuation reach last RU(at bus termination along B1/B1 ' propagation until them).In this RU, B1/B1 ' and B2/B2 ' bus are connected in together so that this signal continues to arrive last RU of this half part of bus along B2/B2 ' propagation until it.Herein, with the characteristic impedance termination.Propagate along the B2/B2 ' part of bus as signal, output is connected and is become effectively, so the whole work stations of this signal back of repercussion.The shortcoming that single worker RU bus node is realized is, it wants two lines to realizing, and because loop returns the cause of topology, total time-delay of the pseudo-bus node of expansion doubles.

In single worker of Figure 10/half-duplex configuration, the person works identical described in the input of circuit and Fig. 8.But in this case, the bus node is operated in single duplex mode, and any employed impulse regenerator must pass through this signal on both direction.With one of input amplifier signal is urged on the RU bus node B1/B1 ', will propagates the excitation output amplifier at both direction along the bus node, as in fact it do.In two terminals of this bus node all with the characteristic impedance termination.

The half-duplex of Figure 11/single worker disposes and uses a two-way amplifier circuit among typical top Fig. 7 that is described.This amplifier is fed back into unidirectional configuration (from left to right or from right to left) in signal is during the delivery time adds timeout interval.The direction of transmission depends on signal and at first appears at which input.This circuit be illustrated in Figure 13 in more detail.The unique difference that has elaborated above the groundwork situation of this circuit and discussed previously is to increase the input and output part that transformer drives with coupling two-way.In half-duplex/single worker's configuration, single transformer T1 is used in two line half-duplex interfaces, and transformer T2 that separates and T3 are used in four those sides of line list worker.The signal that comes from half-duplex one side be added to simultaneously each of bidirectional lines unidirectional half.Online that side of single worker, T2 is coupled to RU pseudo-bus node to signal to B1/B1 ', transformer T3 coupling simultaneously from the pseudo-bus node to the signal of B2/B2 ' to amplifier, amplifier will drive this signal to static that side of half-duplex of standing.

The half-duplex of Figure 12/half-duplex configuration can be understood by the discussion of front.Figure 15 provides the details that half-duplex/half-duplex bidirectional drives.With unique difference of Figure 15 be that associating T2 and T3 become a public transformer T2.

Figure 15 and 16 illustrates the I/O part that bidirectional drive is applied to RU.When using two line half-duplex bus node implementation methods, the arbitrary impulse regenerator (PRU) that requires to be used for the expansion of pseudo-bus node must be two-way, and can use half-duplex I/O is linked described same technology.Figure 17 represents for the expansion of half-duplex bus node, how to realize two-way PRU.With the main difference of Figure 15 and 16 is to increase shaping pulse this signal that goes to regenerate, with the deterioration of erasure signal on electrical property.Shown low pass filter is in parallel with bidirectional drive to be unique needs, connects if these lines just are being used to audio frequency.

The flexibility of the interconnection of disclosed technology provides a good chance to remove to make full use of packeting controller 70, if this advantage does not cause the words of the shortcoming of interconnectivity.In this technology, packeting controller 70 is placed in the distribution case, and accepts the connection (see figure 8) from the grouping work station.Packeting controller is repeatedly kicked among the RU, and the whole group device is repeatedly kicked into network with a controller.

Intelligent router is shown in Figure 15, and it provides another kind of method to go to strengthen the performance and the versatility of cheap network.The front is mentioned with regard to electric consideration, use this technology what restriction is the scale of network in fact do not had.But, depending on applied environment, can allow to obtain in this problem of network of much rule grooves according to user's number definite, performance is considered to become a limiting factor.By address smoothing is provided, router can allow to produce very large-scale network and the relevant deterioration of unlikely generation.

Importantly, cheap network selecting allow through a suitable passage more easily and the LAN(localized network of superior performance arranged) as if Ethernet link.On function, this passage has two interface channels, gives high-performance and low performance LAN each one.This passage must provide required arbitrary protocol conversion, particularly, if disclosed technology is according to CSMA(two lines) the method realization, need reset the collision detection characteristic.

Though the present invention is described by specific embodiment, those skilled in the art may appreciate that: under the situation of not leaving true spirit of the present invention and scope, can do various variations and replace component there with equivalent.And, under the situation that does not break away from the technology of the present invention essence, can make many remodeling.

Claims (2)

1, a kind of localized network of communicating between the node more than two or two of being used for, each node comprise and are used to produce with the telephone set of received audio signal and are used to produce work station with receiving digital signals that described network comprises;

The telephone exchange machine that is used for exchange of audio signals;

The data bus means that is used for transmission of digital signals;

Wherein each node also comprises:

The telephone wire device;

Be used for coupling audio signal between described telephone set and described telephone wire device but first device of the digital signal that is not coupled;

Be used between described work station and described telephone wire device the coupling digital signal but second of the coupling audio signal device;

It is characterized in that described node also comprises;

Be used for coupling audio signal between described exchange apparatus and described telephone wire device but the 3rd device of the digital signal that is not coupled;

Be used between described data bus means and described telephone wire device the coupling digital signal but the 4th device of coupling audio signal not;

Described data-signal communication and described audio signal communication can work and not disturb mutually simultaneously.

2, network as claimed in claim 1 it is characterized in that the described first and the 3rd device is a low pass filter, and the described second and the 4th device is a high pass filter.

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