CN1169810A - Method and apparatus for random in-slot multi-address insertion with collision detection in cable telephoue system - Google Patents

Abstract

A method and apparatus in a communications system (100) for providing communications units (134) access to the communications system (100). The communications. system (100) includes a cable distribution network (106) with an base communications unit (102) and a number of downstream communications units (134) all connected to the cable distribution network (106). A plurality of channels are used to transmit data between the base communications unit (102) and the downstream communications units (134). A first set of channels are used primarily for access the communications system (100) and a second set of channels are used for transmitting data within the communications system (100) after access to the communications system (100) has been gained. The base communications unit (102) sends a first type of data transmission including an identification of access channels used for requesting access to the communications system (100). The base communications unit (102) assigns channels within the second set of channels response to receiving a request for access to the communications system (100) on the first set of channels. A mechanism also is provided for handling collisions in transmissions between the downstream communications units (134) to the base communications unit (102) in attempting to gain access to the communications system (100).

Description

The method and apparatus that has the multiple access of the time slot at random access of collision detection in the cable telephone system

The present invention relates generally to communication system, refer more particularly to a kind of method and apparatus of the many cables access device that is used to insert cable telephone system.

In the cable telephony communication system, adopt frequency division multiplexing (FDM).By in frequency spectrum blocks, dividing with the minimum channel spacing, the different piece of usable spectrum is assigned to each channel, FDM allows to obtain two or more continuous channels simultaneously from transmission medium.FDM provides the physical channel (different frequency just) of fixed qty in the cable telephony communication system.In order to provide more channel, adopt Time Division Multiplexing to increase the number of users that can be operated in the cable telephony communication system.TDM provides the time division multiple access access, and wherein the user shares a carrier frequency by once being assigned and using a time division multiplex channel (time slot) in the finite time section in communication system.In fact, each user has been assigned a different time slot on the same frequency, and in this way, many users can share identical frequency.Transfer of data sends in time slot, wherein assigns a particular time-slot to give communication unit, only uses one limited period for it.

One of difficult problem of tdma system is the real-time access that how to offer user TDMA channel.Relevant difficult problem is to solve the conflict of two or more users when attempting to insert or use identical TDMA channel.Therefore, need the real-time access that a system can provide the TDMA channel fine, can solve the conflict of a plurality of users when attempting to use same channel again fine.

The novel properties that characteristic of the present invention guaranteed proposes in the appended claim book.Yet, by detailed description, and read relevant figure with reference to following a kind of exemplary embodiments, can understand the present invention itself best, and the optimal way that uses, and its further purpose and advantage, in relevant figure:

Fig. 1 is the figure that can realize communication system of the present invention;

Fig. 2 A is the block diagram of element in cable control unit according to the present invention (CCU);

Fig. 2 B is the block diagram of element in cable access units according to the present invention (CAU);

Fig. 3 is the diagram according to the spectrum allocation may of communication system of the present invention;

Fig. 4 A is the figure according to superframe used in the present invention;

Fig. 4 B is the diagram of down channel and up channel;

Fig. 5 A-5K is in the diagram that is provided to the different types of information pulse train that is adopted in inserting according to the CAU of communication system of the present invention;

Fig. 6 is the state diagram of the CAU during system according to the present invention access procedure;

Fig. 7 is the state diagram of the CCU during system according to the present invention access procedure;

Fig. 8 describes with the pulse train of the TDMA up link of a time slot standard of TDMA down link;

Fig. 9 is during CAU attempts being linked into according to communication system of the present invention, the flow chart of the process that CCU adopted;

Figure 10 is the flow chart of the access adopted of CAU according to the process of communication system of the present invention;

Figure 11 is the figure according to pulse train in the down control channel of the present invention;

Figure 12 handles a plurality of more detailed flow charts of attempting to insert according to the process of the conflict between the CAU of communication system of the present invention;

Figure 13 is according to the present invention, in response to the conflict between the CAU pulse train that sends to CCU, the flow chart of the performed process of a character error indicating device (WE1) bit is set by CCU;

Figure 14 illustrates and inserts under the confirmed situation CAU on the system cut-in channel (SAC) and the signaling between the CCU;

Figure 15 is illustrated in and inserts under the unaccepted situation signaling between CAU on the SAC and CCU;

Figure 16 is CAU that reconnects the request of access and the diagram of the signaling between the CCU that causes a success;

Figure 17 causes the CAU that reconnects the request of access of a failure and the signaling diagram between the CCU;

Figure 18 is used to once the diagram of the signal of the additional call request access on the low channel.

The preferred embodiments of the present invention allow a plurality of cable telephone system users to insert tdma system channel (this channel bearing is called out) in real time.Simultaneously, the exquisite conflict that has also solved effectively when two users attempt to be linked into same channel of this realization.Some is relevant for this realization and two kinds of air interface communication agreements, these two kinds of agreements respectively (TR-INS-DD13B) and description among the Personal Access Communications System Air Interfacestandard J-STD-014 (PACS) that publishes of the Technical Ad HocGroup 3 of TI/TIA Joint Technical Committee at Generic Criteria forVersion 0.1 Wireless Access Communications Systems (WACS) that Bellcore 1993 publishes, these documents are by quoting in the description that can be incorporated into herein in addition.

The overall view to cable telephone system has at first been stated in following description.Having described the electronic device of this system in the part of cable companies general headquarters (" general headquarters (headend) ") then, is the electronic device that is positioned at the environment division of user's dwelling house or office subsequently.

This description has explained subsequently how the usable spectrum on the cable uses in cable telephone system.Subsequently, it is how to be divided into time slot that the employed frequency of this system has been discussed in this description, and those time slots are the structures that how to be organized into the digital massage that they carry.Then, some are sent the optional network specific digit message that is beneficial to channel access and conflict solution back and forth in system, described the particular message form.

State diagram then has been discussed, and these state diagrams have illustrated the processing procedure of subscriber equipment when certain user is linked into the TDMA channel and the processing procedure of home office facility.Then, show the flow chart of explanation relevant treatment.At last, show example and discussed when offering subscriber channel and insert, and the specific signaling situation that is taken place when solving conflict between a plurality of users that attempt to be linked into identical letter.

I. the summation of cable telephone system

Referring now to this figure,,, the figure that can realize communication system of the present invention has been described especially referring to Fig. 1.Communication system 100 is examples of a kind of basic cable system architecture, and this architecture is to use the combination of optical fiber and coaxial cable with hybrid fiber/coaxial (HFC) system of distribution customer service to CPE.Alternatively, communication system 100 can be fully by coaxial cable, optical fiber, and perhaps other suitable communication medium is formed.No matter the foundation structure of cable how, a cable branch provides service to the distributed areas that a user community is shared.In described example, communication system 100 is the cable telephony communication systems that telephone service and cable television service are provided on HFC TV foundation structure.

Comprise by a distributed network 106 and combiner 108 by system 100 and to be connected to other basic communication unit of a cable control unit (CCD) 102 of user 104 or some.CCU is in residence user distribution with from the part at the equipment of residence user receipt of call in cable companies general headquarters.Combiner 108 also has the input of a video source 110.CCU102 also comprises cableport transceiver (CPX) 112, and it is connected to combiner 108.These cableport transceivers produce the descending carrier channel in communication system 100.Used " descending " or " down link " is meant wireless frequency (RF) signal of going to user's dwelling house in this description." up " or " up link " used in this description is meant the RF signal that mails to general headquarters from the user.

The CPX112 of combiner 108 from video source 110 and CCU102 receives modulated RF carrier wave, and these signals are accumulated in together, sends by distributed network 106.CPX112 is by controller 114 controls, and controller 114 provides support system with the required all functions of data link part." data link part " is meant the form carrying call of the numerical data of system, and the performance of carrying any other communication with digital data form.The general headquarters of communication system generally comprise CCU102, combiner 108 and video source 110, and digital switch 116 can be positioned at the far-end of general headquarters, perhaps can be positioned at general headquarters itself.These elements are home office facilitys of being responsible for providing to the cable system 100 of serving a plurality of users service access and management.The digital carrier equipment that controller 11 among the CCU102 passes through, for example T ₁Or E ₁, being connected to switch 116, switch 116 correspondingly is connected to public switched telephone network (PSTN) 118 again.Switch 116 can be, for example type 5 TELCO switches.

Downlink optical fiber trunk line 120 and uplink optical fibers trunk line 122 help transmitting in distributed network 106 from the information of CCU102.These Optical fiber relay lines are optical fiber cables, and are connected to Fiber Node 124.Fiber Node 124 is carried out the direct conversion between the electrical domain of the optical arena of optical fiber cable and coaxial cable in distributed network 106.Each Fiber Node 124 is connected to a coverage 126 at least.In described example, coverage 126 comprises coaxial cable, and comprises relay amplifier 128, and in described example, relay amplifier 128 is two-way amplifiers.In addition, bidirectional line stretcher 130 is positioned near the tap 132, and they are connected to the cable access units (CAU) 134 that is positioned at user 104 places.These CAU are also referred to as " subscriber communication units ".

CCU102 is used for providing telephone service (and other digital data communications) in communication system 100.In addition, CCU102 is controlling the cable spectrum of all CAU in the coverage, infrastructure resources, and professional, and manage a plurality of coverages.CAU134 provides phone and television services at user front end.Usually, CAU is installed in user's dwelling house one side, perhaps at the place that can not swarmed into by the people, for example a basement or a loft.CAU manages uplink and downlink communication route, and transmits the cable TV channel to user's television set.For example, (POTS) insert CAU at " the common formula phone of returning " of user's premises.This CAU will import in the cable system from the telephone signal of POTS.In addition, this CAU takes out call from cable system, and is given to POTS with before them, and takes out normal cable TV signal from cable, and sends them to user's television set.

II. the electronic device summation in CCU and CAU

Referring to Fig. 2 A, described below according to the element block diagram in the CCU control unit of the present invention.In CCU200, the TDMA pulse train that up pulse receiver 202 receives from CAU, and convert this pulse train to base band quadrature I and Q signal downwards." pulse train " is the transfer of data that a kind of form of fixing bit with beared information is carried out.This pulse train is modulated through PI/4-DQPSK.Convert these I and Q signal to digital signal by modulus (A/D) transducer 204 and 206, and handling by 208 pairs of digital uplink signal processors (DSP).In described example, A/D converter 204 and 206 is 8 bit A/D transducers.The information that up DSP208 sends after handling to microprocessor 210.

Microprocessor 210 is beamed back this CAU by descending DSP212 and descending TDM transmitter 214 with message, and descending TDM transmitter 214 is connected to the communication network that this CAU is positioned at.

Up pulse receiver 202, A/D converter 204 and 206, up DSP208, microprocessor 210, descending DSP212 and down-link transmitter 214 are detectable elements in the CPX112 of Fig. 1.Can be positioned at same transceiver or different transceivers (CPX) with illustrated upward element in the downstream elements shown in Fig. 2 A.Up DSP208, microprocessor 210 and descending DSP212 have formed a processing unit among Fig. 2 A.In the controller 114 of Fig. 1, can find microprocessor 210.DSP among this microprocessor and the CPX112 has formed the processing unit among the CCU102.

Referring now to Fig. 2 B,, shows according to the element block diagram in the cable access units of the present invention (CAU).CAU250 is connected to hybrid coaxial cable in the distributed network 106 of Fig. 1 by RF interface and control 252.This interface and control unit provide 75 ohm of interfaces of hybrid coaxial cable.RF interface and control 252 also provide being connected of cable television appliances of user front end.In addition, RF interface and control 252 comprise a control switch, in order to open or close the signal of front end cable television system at user front end.The data from CCU in RF interface and control 252 receptions are sent out digit receiver (demodulator) 254.The signal that receives from CCU is positioned at the frequency range from about 50MHz to 750MHz, and to the low intermediate frequency (IF) of converting by digit receiver 254.Digit receiver 254 becomes base band π/4 DPQSK modulated signals with low frequency IF from this formal transformation.This signal of demodulation subsequently is to obtain bit from signal.Afterwards, data/clock recovery 256 is obtained these bits from digit receiver 254, and separates these bits to be sent to processing unit 258 or pulse-code modulation (PCM) coder/decoder (codec) 260.When user data was sent to PCM codec 260, control information was sent to processing unit 258, and PCM codec 260 converts user data to analog form, is sent to subscriber phone.

In the example shown, processing unit 258 comprises one or more microprocessors or digital signal processor (DSP), and random-access memory (ram) and read-only memory (R0M).RAM and ROM comprise data and instruction, and these data and instruction are encoded, and are handled by microprocessor or DSP in the processing unit 258.User profile converts analog form to by PCM codec 260, and is sent to local loop interface (SLIC) 262.

SLIC262 provides basic telephony feature, for example indicates phone whether ring or off-hook, and whether the loop closure has perhaps taken place.In addition, SLIC262 is separated into a branch feed signals and a received signal with two I signals.To those skilled in the art, SLIC262 and its performed function are well-known.In fact ringing current generator 264 provides in order to cause the voltage of phone ringing.

User data (for example output of phone from user front end, perhaps or even the output of standard computer modulator-demodulator) send it back PCM codec 260 by SLIC262, the latter is transformed into digital form with these data from analog form and handles for sending data framing 266.Send data framing 266 and obtain primary voice data, and with this data set framing to send to CCU.For example, send data framing 266 and comprise essential synchronizing information, and calculate and be used to the cyclic redundancy code of makeing mistakes and detecting, this cyclic redundancy code is placed into low channel frame (following will the description in more detail).Send data framing 266 by processing unit 258 controls, and transmission and the synchronous signal uplink stream of downstream signal.Send this in the data framing 266 synchronously by data/clock recovery 256 controls.In other words, be synchronous to the uplink of CAU250 with from the downlink transfer of CAU250.At last, these data send to RF interface and control 252 as the pulse thing by digit emitter (modulator) 268, and send it back CCU.

III. the RF carrier frequency separation in the carrier wave, the bit architecture of time slot and single time slot

In Fig. 1, can comprise voice and non-speech data simultaneously, ISDN digital video for example, phone data, interactive video, perhaps interactive multimedia business through the carrying data of distributed network 106.In the present invention, the employed transmission technology of cable telephony exchange service is a middling speed.In other words, the cable telephony traffic channel is not to be exclusively used in certain specific user, but all users can use based on service request.This configuration is called as the multiple access access or local loop is concentrated.

Usually, a particular channel is assigned to a user, and it is assigned to this user all the time in call duration.When this call out to stop, this user's temporary transient appointment is cancelled, request is available to this channel to follow-up business.Therefore, CCU can serve in the coverage more than the many users of number of available channels.In addition, have in its coverage of physically isolated cable layout at each, entire spectrum can repeat function.

According to the present invention, cable telephone system is divided wireless frequency (RF) frequency spectrum and is used for a plurality of users, so that each user does not have the dedicated frequency scope.

Referring to Fig. 3, show spectrum allocation may diagram according to communication system 100 of the present invention.As mentioned above, in each coverage of distributed network 106, distributing to professional frequency spectrum in single coverage can be reused by other a different set of user.In the example shown, RF spectrum 300 comprises uplink spectrum 302 and downstream spectrum 304.In the example shown, uplink spectrum covers the scope from 5MHz to 42MHz, and the scope that downstream frequency 306 covers from 50MHz to 750MHz.These two frequency spectrums further are divided into the channel that each width is 6MHz.In the example shown, downstream spectrum 306 comprises 120 channels, and each channel is wide to be 6MHz.Although shown in example show 5 downstream spectrum 306 to the uplink spectrum of 42MHz and 50 to 750MHz, and each channel wide be 6MHz, can use other frequency spectrum and channel width according to the present invention.

Communication system 100 is divided into the zone with unlike signal path, and wherein in each zones of different of distributed network 106, the RF spectrum of distributing to the cable telephony business can be reused by other a different set of user.On downlink transfer, a large amount of traditional tv channel (for example 80 channels, each 6MHz is wide) generally is transferred to the cable TV subscriber.Uplink spectrum (5-42MHz) can be used for returning any communication in back from the user.A part downstream spectrum, preferably a 6MHz part as shown in Figure 3.And one equates or bigger part is exclusively used in a plurality of junction traffic channels in uplink spectrum, these junction traffic channel services in have in a large number phone and/user of other two-way services.In these special-purpose spectrum allocation may, adopt a large amount of RF carrier waves (illustrating for example) by part 303.These RF carrier waves are at a distance of 600KHz.Enliven carrier wave and work in pairs, be associated, the carrier wave of an ascender that is distributed is all arranged with the carrier wave of each descender.This association provides Frequency Division Duplexing (FDD) (FDD) operation.Yet it is fully flexibly that system can mate aspect any down channel at any up channel.

Correspondingly, in a preferred embodiment of the invention, a 6MHz part (being positioned at the somewhere of 50-750MHz) comprises 10 600KHz RF carrier waves 303 that are used for downlink communication.Similarly, a 6MHz part (being positioned at the somewhere of 5-42MHz) comprises 10 600KHz RF carrier waves 303 that are used for uplink communication.

According to describing this scheme, each RF carrier wave is gone into 8 serials " frame " by time division multiplexing.Each frame further is divided into 8 serials " time slot ".Each such time slot is the time division multiplexing " channel " that a user can be used in real time.Fig. 4 A shows such scheme graphically.This figure represents a RF carrier wave.This carrier wave is divided into 8 frames 399.Each frame is divided into 8 time slots 401, and each time slot 401 is channels.Shown whole frame 400, just 8 frames of being made up of 8 time slots are called as a multi-frame sometimes.

Fig. 4 B shows this scheme by different way.Fig. 4 B shows descending carrier 402 and up-link carrier 406.More specifically, referring to carrier wave 402, show two continuous frames 404 and 405.These are two in 8 frames 399 among Fig. 4 A.Each frame is made up of 8 continuous slots 407.Each time slot can be used as a communication channel in the cable telephone system.Illustrated as Fig. 4 B, up-link carrier 406 disposes in the mode identical with descending carrier 402.

Each time slot further is divided into the dissimilar signaling of being used by CCU or CAU.For example, as shown in the drawing, the time slot 1 in the frame 404 comprises a synchronizing channel (SYC) 414,418, one fast channels of 416, one slow channels of a control channel (CC) (SC) (FC) 420, and an error control channel (EC) 422, synchronizing channel 414 is the synchronizing channels that are used for frame synchronization.CC416 is used to indicate word error, signaling and power control.SC418 is used for signaling, and FC420 is used for user data and signaling.EC422 is used for error detection occurs.In the uplink and downlink pulse train, SC418 comprises 26 bits, and FC420 comprises 160 bits, and EC422 comprises 20 bits.CC416 comprises 2 bits on upstream bursts, and comprises 9 bits in the downstream pulses string.Below will discuss the optional network specific digit message of these different pieces of using time slot in more detail.

According to the present invention, CCU channel 402 is the down channels that send in the frequency range of 750MHz at 50MHz, and CAU channel 406 is the up channels that send in the frequency range of 42MHz at 5MHz.Transfer of data in these channels is sent out as one " pulse train ", and " pulse train " is the transfer of data of a regular length, the transmission of similar one group of bit.In the example shown, a pulse train is 224 bits of each time slot in CAU channel 406, and in CCU channel 402 240 bits of each time slot.

On the uplink and downlink link, each time slot may be used to dissimilar channels, a system broadcast channel (SBC) for example, a system cut-in channel (SAC), perhaps a Traffic Channel (TCH).In these different " channels " each all has different functions.8BC and SAC can be considered to system cut-in channel because of its function.SBC on down link to the monitoring this SBC all CAU broadcast system informations.Information in the descending SBC bearing system scope for example is used for the alarm of " paging " certain CAU and is used to control and manage the system data library information of CAU.A SBC is divided into two the logical message streams of time division multiplexing to this SBC.Specifically, a system information channel (SIC) and alarm channel (AC) time division multiplexing are to this SBC.Certain CAU locatees this SBC and monitors this SIC, to obtain the common information of interest of all devices that is connected to this CAU.According to the present invention, common system banner and the performance of this SIC identification; The security information that is used for authentication and encryption; And carrier frequency, the position of SBC and SAC.

On AC, use message to notify or the certain information of " paging " certain CAU, for example come to visit for one.These message comprise alarm identifier.Each CAU is assigned an alarm identifier, and monitors this AC to determine whether certain message on the AC is directed to it.Use a plurality of SBC in communication system, to provide redundant.

CAU uses SAC to obtain a TCH and assigns, so that this CAU handles call, perhaps sends other numerical data.In addition, this CAU monitors the AC of this SBC to find incoming notifying.

SAC is three kinds of logic channels of transmission, time standard channel (TAC), a physical channel of request access channel (RAC) and system request channel (SRC).TAC is carried on the upstream bursts (SUB) of the shortening that is used for time calibration in the up link, and the access request in the RAC carrying up link.The SRC carrying is from the response to upstream message of CAU.SAC is used for time of implementation calibration and request and/or assigns TCH.As its result, CAU will use SAC for one of following purpose: time calibration, the initial request of Traffic Channel perhaps reconnects to Traffic Channel.Use a plurality of SAC (a plurality of time slots on identical or different carrier wave just) providing redundant, and reduce the competition between a plurality of CAU that require to be linked into this communication system.TCH offers the business on the user communication system, and may be requested or assign into different speed.TCH is divided into two class subchannels: user profile channel (UIC) and message channel (MC).UIC carries user profile, for example speech data or analog modem data, and MC is carrier signaling information between CCU and CAU.TCH or busy (using) or idle (not using).According to the present invention, access channel (SBC and SAC) can move to different frequencies according to the quality of carrier transmission with data channel (TCH).The change of SAC frequency causes the new frequency of broadcasting on SBC.By using a reserve link conversion (ALT), allow CAU no matter channel moves to another frequency, keep the frequency shift that TCH is carried out in connection all the time.ALT is well-known in radio communication, but is used for keeping calling when move the position between a plurality of honeycombs of user at cellular system because of historical reasons.

V. the format and content of particular message

Referring to Fig. 5 A-5K, illustrate according to the present invention, at a plurality of requests that provide CAU to be adopted in the access of communication system and the burst of response forms.In the communication unit message between CCU and the CAU for example, comprise and insert request number (ARN) to discern certain particular message which CAU that leads.ARN is unique to each CAU in a coverage.ARN is in order to unique identification message, for example asks and responds.All pulse trains or request from CAU all comprise an ARN to identify the originating source of this pulse train.Similarly, when beaming back response to CAU, CAU can discern this response and be sent to CAU based on being included in from the ARN in the response of CCU.

According to the present invention, adopt ARN, for example ARN500 among Fig. 5 A.ARN500 is the ARN of 24 bits, comprises a warning value, an alert phrase and a random number.Alert phrase indication CAU in a multi-frame will monitor the time period of SBC.The use of this alert phrase allows CAU to be in standby or sleep mode, and only activates its receiver in the time period of a weak point.CAU will keep mode in the sleep in most of reframing time, and will only activate its receiver in its alert phrase, thereby reduce power consumption.Warning value is the unique identification that is assigned to CAU, and is unique in the stage in specific warnings.Alert phrase and warning value have been formed an alarm identifier, and this alarm identifier is unique in a coverage.In ARN500, comprise a random number, will can not produce identical ARN once more to guarantee the CAU in the clothes zone.

In some instances, adopt 3 bit A RN to be identified at the message between CAU and the CCU.Specifically, when CAU has had a TCH, and on SC, send and use 3 to compare ARN when receiving message.Because in the example shown, between CCU and CAU, set up connection, mean that not having other CAU uses this channel, so can adopt 3 bit A RN.As its result, CCU only needs to distinguish the difference request that this CAU may send.3 bit values allow to support that the CAU of many circuits or TCH uses 8 ARN.

When access communication system, SAC message is comprised in the individual pulse string, is inserted coequally by any CAU to allow each SAC frame.Usually, the message on the SAC uses full-time crack.Like this, the imbalance of upstream bursts will cause clashing with other uplink.Use one to shorten upstream bursts (SUB) like this, at first to determine whether and to change calibration from the upstream bursts of CAU.In Fig. 5 B, according to the present invention, the length of SUB502 less than half time slot to avoid interference adjacent time-slots.CCU utilizes the position of SUB502 in time slot, determines that what kind of needs to do in time slot changes with the pulse train of calibration by the CAD transmission, makes the words of this change if desired.In the example shown, SUB502 comprises 3 synchronous modes, synchronous mode 504 (shown in Fig. 5 C) for example, a differential encoder (DE) and an ARN, for example ARN500 among Fig. 5 A.In Fig. 5 B, by same synchronous mode triplicate, CCU correctly receives and the possibility of this synchronous mode of decoding to increase at SUB.DE is a two bit value, arrives CCU in order to indicate a pulse train, and decoding should begin.

Then, response was in response to and received a SUB time calibration, sent to CAU to indicate whether to do the timing of upstream bursts the response of change by CCU.Referring to Fig. 5 D, respond time calibration 506 comprise one time calibration value, what kind of the indication of this value need be done to the timing of upstream bursts transmission and change with in time slot internal calibration upstream bursts.This value has especially been indicated in the variation that receives the time difference between downstream pulses string and the transmission upstream bursts.This response also comprises a power control indicating device (PCI) and a power adjustment, informs CAU when sending pulse train, and how many transmission power value this CAU should use.PCI informs whether CAU increases or reduce transmission power value, and the amplitude that power adjustment indicated horsepower value is adjusted.

CAU sends initial an access to CCU and asks on RAC, for example initial access request 508 among Fig. 5 E inserts request to start a system at CCU.The TCH that initial access request 508 signs are assigned to CAU is desirable, and/or acceptable maximum bandwidth rate and minimum bandwidth rate.According to the present invention, in communication system 100 these percentage bandwidths can be 8 kilobits per seconds (Kbps, 16Kbps, 32Kpbps or 64Kbps, initial insert request can also) comprise bit and a time delay value (not shown) of the priority of indicating this request.The priority of request can be used to the business that provides different classes of, voice for example, digital video or ISDN.Delay time value indication CAU is taking other action, for example sends another initial access before the request, will how long wait for Channel Assignment.

Further, assign the CAU of a TCH can send initial an access by initial access request 508 and asked for example initial access request 510 among Fig. 5 F.This request sends to (C1) on slow channel.This initial access request on slow channel, general is when this CAU has had a forward connection from the CAU that can handle a plurality of bindings, requires another TCH to be used for a new request that connects.At the initial access request rate that inserts in the request 508 is the desirable bandwidth of new TCH.

Referring to Fig. 5 G, show according to of the present invention and reconnect the request of inserting.The request of reconnecting 512 is because lose synchronously with TCH, and is sent to the request that requires another TCH of CCU by CAU, and is attempting reconnecting to send to CCU in the calling on RAC.Lose and to occur in TCH synchronously and be assigned, and CAU is not when receiving new carrier wave notice, if perhaps physics links and is cut off.Reconnect the request of access 512 and comprise a up-link carrier ID and a descending carrier ID, point out the employed initial TCH of CAD.Whether flag bit indication time slot and bandwidth territory are associated with an active TCH.In reconnecting the request of access 512, use a plurality of time slots and bandwidth territory, ask reconnecting of all TCH simultaneously to allow the CAD that can handle a plurality of TCH.

In response to the request from CAU, CCU sends and to insert the responses that confirm response a plurality of comprising, inserts to confirm that response 514 is in response to from CAN and system and insert request and send.Fig. 5 H shows one and send to the access confirmation response 514 that CAU reads CAU to assign a TCH to give from CCU on SRC.Insert and confirm that response 514 comprises Channel Assignment information, for example with the relevant time slot and the bandwidth of TCH of assigning.The time slot territory informs which time slot CAU uses, and the bandwidth territory informs that CAU which frame in multi-frame is used to send pulse train, for example the superframe 400 among Fig. 4 A.For example, time slot 2 and bandwidth 64Kbps inform that CAU sends at the time slot 2 of each frame of multi-frame 400, and time slot 2 and bandwidth 32Kbps inform that CAD sends in the time slot 2 of a frame in multi-frame 400.Whether the flag bit indication has found useful information in relevant time slot and bandwidth territory.An initial access is asked, because only assign a TCH, so have only a time slot and bandwidth territory to comprise the information of this CAU in response to an initial access request.When request is used to reconnect, reconnect when receiving in the CAU request that can handle TCH more than a TCH, can use other time slot and bandwidth territory.

Insert to confirm the initial access request that response can also be sent in response to CAU on slow channel, on slow channel, sending to CAU, confirm shown in the response 516 as inserting among Fig. 5 I by CCU.Send this class and insert the confirmation response to be assigned to another Traffic Channel of CAU to be used for new connection.Insert and confirm that response 516 comprises bandwidth and the time slot mark of the new TCH that is assigned to CAU.

Referring to Fig. 5 J, admission reject response 518 is to send to CAU inserts request with the system of refusal CAU message by CCU on SRC.Sending this response will not assign a TCH to this CAU to inform CAU.On slow channel, the admission reject response 520 of Fig. 5 K is that another TCH of refusal CAU is to be used for new connection.The admission reject response comprises a cause value, and indication inserts unaccepted reason.The reason that refusal inserts can comprise that for example, available cable resource is not enough, and available network resource is not enough, and it is impossible to reconnect, perhaps because some uncertain reason refusals provide professional.

VI. allocated channel is given the CAU of CAU and the state diagram of CCU

Referring now to Fig. 6,, shows CAU state diagram according to system of the present invention access procedure.State diagram 600 shows the different conditions of the CAU that takes place when access communication system 100.CAU starts from idle condition A0.At this state, select a SAC randomly based on the number of the SAC that in S1C, broadcasts.CAU locatees selected SAC on suitable descending carrier, and moves to synchronous regime A1, and this state is a CAU SAC synchronous regime.Any access confirmation that receives in idle condition A0 or admission reject response all are left in the basket, because CAU does not monitor SAC at that time.If system send to insert confirm or the admission reject response before, user's on-hook, then CAU will receive in these responses one.When CAU detected the loop closure, CAU returned this SBC of monitoring, this means that CAU will not receive the SAC response from CCU.As its result, CCU must can detect dead link, and dead link is the Traffic Channel of having assigned that CAU does not send.At all other states, if CAU detects the loop closure from the telephone plant that is positioned at user front end, this CAU will turn back to state A0 and continue monitoring SBC.

At synchronous regime A1, CAU attempts with SAC synchronous in a period of time continuously.If CAU has surpassed selected number of retries, then this CAU shifts the not busy state A0 that makes the return trip empty, and can select another SAC to insert at this state CAU, perhaps to higher layer protocol entities indication access failure more.CAU and SAC synchronously after, the up indication of CAU stand-by period calibration channel (TAC).When detecting TAC, CAU sends one and shortens upstream bursts (SUB) on TAC, and starts and respond timer a time calibration, transfers to align mode A2.Respond timer time calibration a finite time amount is set,, then resend a SUB if do not receive message time calibration in the period from CCU at this section.

In align mode A2, CAU waits for message time calibration from CCU.If conflict has taken place, perhaps, respond timer time calibration then receiving time calibration from CCU before the message, then CAU adjusts its transmitted power, and sends SUB again until selected number of times on SAC.To be the transmitted power that is used to adjust CAU can reach value with respect to the value of the optimization decay of performance number to certain to power adjustment.More detailed information about the method for performance number control can obtain in common pending application application Method and Apparatus for Adaptive RFPower Control of Cable Access Units, this patent application, is incorporated into for your guidance in application on October 27 nineteen ninety-five herein by people such as TimothyM.Burke.If surpassed the number of times of SUB retry, this CAU can select another SAC to insert, perhaps to the indication of higher layer protocol entities more access failure.When CAU receives a time calibration during message from CCU, this CAD adjusts its transmission deviant and also waits for the up indication of RAC.When detecting RAC, CAU sends initial an access and asks on RAC, starts one and inserts the response timer and transfer to access state A3.When inserting response word device be one be used to limit CAU wait for from CCU in response to the initial timer that inserts the time quantum of request responding.

Referring to access state A3, CAU waits for access confirmation or the admission reject request from CCU.If insert the response timer then or CAU receive one and receive the refusal request, CAU will resend and insert request message until surpassing number of attempt.Send the reason of a message explanation access failure if surpassed number of retries, CAU, and shift the not busy state A0 that makes the return trip empty.On the other hand, insert authorization request if CAU receives one, this CAU transfers to the Traffic Channel of being assigned subsequently and monitors to carry out signaling, transfers to Traffic Channel (TCH) then and assigns state A4.

Assign state A4 at TCH, CAU waits for normal release or dead link indication of channel.If receive normal a release, CAU shifts the not busy state A0 that makes the return trip empty.On the other hand, if because lose synchronously or reserve link conversion (ALT) failure detection goes out a dead link indication, this CAU will carry out one and reconnect process.Specifically, this CAU selects a SAC and locate selected SAC on suitable descending carrier, transfers to synchronous regime A1.

Referring now to Fig. 7,, shows according to the employed CCU state diagram of system of the present invention access procedure.State diagram 700 shows at CAU and handles the different conditions that inserts the CCU that takes place when asking.CCU starts from idle condition B0, and CCU can receive or an initial access request in this state, a SUB, and perhaps one reconnects the request of access.CCU receives one and initially inserts common priority that request causes CCU with this request queue, and transfers to solicited status B1.Reconnect when inserting request receiving one, CCU, and can move on to and reconnects state B2 this request queue with high priority.Receive a SUB and cause that CCU calibrates and the power adjustment information computing time, formats a response, and transfers to dispatch state B3.

Refer now to solicited status B1, CCU judges whether have the ability of finishing this access request.If this CCU does not have this ability, this CCU produces an admission reject response subsequently, and transfers to dispatch state B3.If this CCU can finish this request, it waits for an available TCH.When certain TCH can be used for assigning, this CCU checks the stand-by period of this request, if stand-by period that should request greater than the selected time period, this TCH is assigned to another request, and from formation, removing this out-of-date request, this CCU shifts the not busy state B0 that makes the return trip empty.If amount seclected time that the stand-by period of this request points out as delay value in its initial access request less than CAU, this CCU generates one and inserts the confirmation response, and transfers to dispatch state B3.

Reconnecting state B2, this CCU judges whether this time calling can be reconnected.If this calling can not be reconnected, this CCU generates a refusal response, and transfers to dispatch state B3.If this CCU can reconnect this time calling, this CCU waits for an available Traffic Channel.When certain TCH can be used to assign, this CCU checked the stand-by period of this request.If the time quantum that the stand-by period of this request points out as delay value in its initial access request greater than CAU, this request is " out-of-date ", this CCU asks this traffic-channel assignment to another, and removes this out-of-date request from formation, shifts the not busy state B0 that makes the return trip empty.If it is out-of-date that this request does not have, and be not more than selected time quantum, this CCU generates one and inserts the confirmation response and transfer to dispatch state B3.In dispatch state B3, a response sends once to AUU from this CCU.After sending the response of a time calibration or admission reject, this CCU shifts the not busy state B0 that makes the return trip empty.After sending an access confirmation response, this CCU starts a confirmation timer, and transfers to confirmation state B4.The confirmation timer indicates this CCU will wait in being assigned to its time slot from first pulse train of CAU and the time quantum of access confirmation response.

Confirming state B4, confirming that timer enlivens, and CCU waits for and confirms to send to this upstream bursts on the TCH that CAU assigned.If this appointment is proved, this CCU shifts the not busy state B0 that makes the return trip empty.If confirm timer then, this CCU so that the TCH that is assigned is in idle condition, and sends an alarm indication and migration to abandoning state B5 with start-up routine.Just make the TCH that is assigned be in idle condition at the CCU that abandons state B5.Be left in the basket abandoning any upstream bursts that state B5 received.When this TCH had been set to the free time, this CCU shifted the not busy state B0 that makes the return trip empty.

In order to ensure the communication system operate as normal of using TDMA, must be at certain predefine window, be also referred to as the burst transmission of " time slot " internal calibration, and can not overlap, otherwise will cause the pulse train conflict of transmission error with adjacent time-slots from single CAU.With reference to Fig. 8 as can be seen, the pulse train in the TDMA up link 800 is calibrated with the time slot 802 in the TDMA down link.CAU comes the time of implementation calibration by change its burst transmission in time with respect to the relevant TDMA downstream signal that is received.CAU does not know how many propagation delays take place in the network, because its physical location in distribution cable, each CAU has a unique time delay, because the characteristic of distributed network and environmental condition, for example variation of temperature may be adjusted time calibration.

VII explanation allocated channel is given the flow chart of CAU and relevant treatment

The reception of the chopped pulse string that sends from this CAU that the processing window by measuring CAU is relevant utilizes CCU to determine different propagation delays.This time delay is digitized and is transferred to this CAU in descending time slot.Employing is mail to the chopped pulse string of CCU so that the propagation delay of any the unknown is unlikely the conflict that causes between pulse train from CAU.Receiving when counting its burst transmission time during CAU is adjusted at this time and calls out from the delay compensation of CCU.

Referring now to Fig. 9,, shows the flow chart of the processing that CCU carried out during (A1) attempts access communication system according to the present invention.This is handled with a TAC of indication (step 900) beginning in down link.Afterwards, judge whether to have received a CAU SUB (step 902),, then determine to be worth and a calibration of power value (step 904) time calibration if received a CAU SUB from CAU.

More specific, the relative mistake between the position of the starting point of the sample window that the CCU measurement receives and chopped pulse string, this time difference is represented with bit number, has represented the far-end propagation delay.This value is known as value time calibration.Time calibration value time difference from when CCU begins to send the downstream pulses string, measuring the same number of frames sequence number that begins to receive from this CAU, the upstream bursts of time slot and multi-frame on the TAC.The more information of relevant time calibration can find in common pending application application Method and Apparatus for Synchronizing Timing of Components of aTelecommunication System, this patent application is applied in November 29 nineteen ninety-five by people such as Timothy M.Burke, it is incorporated into herein, send this value time calibration (step 906) to CAU.Afterwards, on down link, send RAC (step 908),,, then handle and directly carry out step 908 if do not receive CAU SUB referring again to step 902.

Judge (step 910) with regard to whether receiving the CAU request then.If do not receive the CAU request, handle and then return step (900).Otherwise, judge TCH resource whether available (step 912).If resource can be used, handle then for this CAU sets up a TCH (step 914), afterwards, send one to CAU and insert confirmation response (step 916), processing subsequent turns back to step 900.Referring again to step 912, if resource is unavailable, send an access-reject message (step 918) to this CAU, processing subsequent turns back to step 900.

Refer now to Figure 10, the flow chart of the process that is adopted when showing the CAU access communication system according to the present invention.SBC safeguards that can be used for system inserts SAC to table.This table continues broadcasting in SBC, CAU utilizes this table to select a SAC, and request is linked into communication system.Processing in (step 1002), requires the CAU incident (for example user's off-hook) of a TCH to take place with the acquisition SAC table beginning (step 1000) of CAU monitoring SBC.A retryCounter is set to 0 (step 1004).Select a SAC (step 1006) from SAC table, this CAU is retuning and be synchronized to selected SAC (step 1008) subsequently, judges whether to have realized synchronous (step 1010) with selected SAC then.If do not handle not synchronously, and then judge whether to have surpassed number of retries (step 1012).If do not surpass number of retries, handling increases by 1 (step 1014) with retryCounter, and this processing subsequent turns back to step (1006).Otherwise, handle the high-rise SAC failure (step 1016) of notifying communication system, processing subsequent stops.This communication system comprises one group of service with the hierarchical structure tissue, is similar to Open Systems Interconnection.

If realized that retryCounter is set to 0 (step 1018) synchronously.Afterwards, on TAC, send SUB, and start an overtime timer (step 1020) to CCU.Afterwards, by checking that the word error thing whether occurring in word error indicating device (WEI) judges whether to have taken place conflict (step 1022).According to the present invention, the WEI on the use down link SAC is to detect the conflict between two or more CAU that send in same time slot.For example, when certain CAU at frame number 5, sent a pulse train in the time slot 3, the frame 5 of next multi-frame then, whether the WEI in the time slot 3 will indicate this pulse train successfully to be received by CCU.If conflict has taken place, then judged whether to surpass the number of retries (step 1024) of this selected CAU.If do not surpass number of retries, retryCounter is with increment 1 (step 1026).

Afterwards, delay time (step 1028).In time-delay (step 1028), a random time amount is added into the time delay timer.The time delay of this timer is provided with in the following manner:

Time delay=(random number M0D (2 ^N-1))

Still in step 1028, start the time delay timer, and handle and no longer continue (just send another SUB up to the time delay timer then, proceed to step 1020).Then, processor the above turn back to step 1022.Referring again to step 1024, if surpassed number of retries, handle then to proceed to and notify high-rise SAC failure (step 1016), should handle stopping afterwards.Referring again to step 1022,, then handle to wait for and judge whether to take place overtime or receive response (step 1030) if no conflict occurred.If take place overtimely, handle and to proceed to step 1024 as previously mentioned.Otherwise, adjust time calibration and through-put power (step 1032) according to the indication of receive response.

RetryCounter is set to 0 (step 1034).Afterwards, a TCH request is sent to CCU on RAC, and starts an overtime timer (step 1036), judges and whether indicated conflict (step 1038) in WEI.If indicated conflict, judge whether to have surpassed the number of retries (step 1040) that is provided with for this CAU.If do not exceed number of retries, retryCounter increment 1 (step 1042), processing subsequent is carried out time-delay 1028 as mentioned above, sends this request once more in step 1036 then.

Referring again to step 1040,, handle then proceeding to step 1016 as previously mentioned if surpassed number of retries.If no conflict occurred, then judge whether to have taken place overtime or received response (step 1044).If take place overtimely, handle and to proceed to step 1040 as mentioned above.If receive response, handle then judging whether to have assigned certain TCH (step 1046).If do not assign TCH, handle proceeding to step 1040.Otherwise, handles retuning and be synchronized to this TCH (step 1048), and this TCH of the higher level in the notifying communication system assigns (step 1050), processing termination afterwards.

Use WEI to detect between the communication unit for example deterioration of CCU on the TCH and the transmission quality between the CAU.CCU set WEI bit detects mistake because of the Cyclic Redundancy Check failure with indication in previous pulse train.In the example shown, set WEI in the same number of frames sequence number of next multi-frame and time slot.By determining whether this pulse train is correctly received, and CCU determines whether to detect synchronous mode in pulse train.If CAU or CCU can not detect synchronous mode in pulse train, then taken place to lose synchronously and this WEI will indicate mistake has taken place.

According to the present invention, WEI also is used for detecting at access channel, and for example SAC goes up the conflict between a plurality of CAU that attempt access communication system.The a plurality of CAU that attempt to send pulse train in the identical time slot of SAC and frame cause CCU not detect synchronous mode the pulse train that receives from these CAU.Because two or more CAU attempt to send pulse train in the identical time slot of SAC and frame, rather than because the decline of the transmission quality that is caused by the damage or the external noise source of cable media just causes detecting synchronous mode.In addition, when CRC fails, may clash.

Referring now to Figure 11,, shows the figure that on down control channel, is sent to the pulse train of CAU according to the present invention from CCU.Pulse train 1100 is included in the frame number of bit 1 to 3, and frame number is the frame number of the particular frame of this pulse train among 8 consecutive frames forming multi-frame.In bit 1 to 3 with 0 (" 000 ") to a plurality of frames of 7 (" 111 ") sequence notations.This position of frame in multi-frame of value sign, and be called as frame number.As can be seen, the least important bit of frame at first is transmitted.According to the present invention, bit number 7 is left in the future and uses.Bit number 8 is word error indicating devices, is " 0 " when being free from mistakes for " 1 " when mistake takes place.Bit number 9 in pulse train 1100 is fast channel indicators, and it indicates fast channel whether to comprise signaling information or user profile.

Refer now to Figure 12, show according to the present invention and handle the flow chart more specifically that conflicts between CAU.Processing is to send pulse train (step 1200) beginning in selected time slot and the frame number in up link.Afterwards, in the identical time slot of next multi-frame and frame number, detect downstream pulses string (step 1202) from CCU.Check that the WEI bit is to determine whether that conflict has taken place or whether this pulse train is correctly received (step 1204) by CCU.Because the delay of a multi-frame, after having sent pulse train according to the present invention about 20 milliseconds, CAU receives pulse train and is ruined notice.If conflict has taken place, handle then judging whether to have surpassed number of retries (step 1206).If do not surpass number of retries, handle and then calculate a time quantum randomly, join time delay timer (step 1208).The following calculating of the time delay of this timer:

Time delay=(random number MOD (2 ^N-1))

The time delay that calculates is added into the current time delay (step 1210) of time delay timer subsequently.Start this time delay timer (step 1212), handle and turn back to step 1200 to send another pulse train (step 1213) to CCU then at this time delay timer.Referring again to step 1206,, handle then stopping if surpassed number of retries.In addition, if no conflict occurred in step 1204, this handles termination.

Referring now to Figure 13,, shows as the response to the conflict between the CAU pulse train that sends to CCU, the processing that CCU set WEI bit is carried out according to the present invention.Processing receives the given time slot and the beginning of the pulse train (step 1300) in the frame of up link with the CPX in CCU.Afterwards, judge that whether this pulse train is by correct receive (step 1302).By determining whether this pulse train is correctly received, and CCU determines whether to detect synchronous mode in pulse train, whether the CRC failure perhaps appears.If correctly receive this pulse train, processing is provided with the WEI bit and does not clash (step 1304) with indication.Otherwise processing is provided with this bit and has clashed (step 1306) with indication.In both cases, the value of WEI bit is incorporated in the next superframe corresponding in the pulse train of the identical time slot of reception upstream bursts and frame number (step 1308), handles stopping afterwards.

VIII., the channel access is provided and solves employed burst in the channel competition

Figure 14 has illustrated the signaling that inserts under the confirmed situation between the CAU and CCU by channel SAC and TCH.

Send a SUB from CAU to CCU on SAC, CCU sends it back a time calibration signal to CAU.Afterwards, CAU sends an initial access request on RAC.

CCU inserts request to each that receives and ranks.The information that the CCU storage is sent in uplink by CAU, and receive the channel address (carrier wave and time slot) that system inserts.Afterwards, this CCU sends a success response or a unsuccessful response on it receives the down link of SAC of request.

Figure 15 shows and inserts under the unaccepted situation signaling between CAU and the CCU on SAC.CAU sends one to CCU and shortens upstream bursts, and the CCU response is with response time calibration.Afterwards, this CAU sends initial an access and asks to CCU, and as Figure 14, yet in this case, CCU responds with an admission reject response.When access was rejected, this CAU can retransmit the initial access request of sending, and perhaps report has surpassed maximum re-try attempt number of times.

Channel is meant carrier wave and the single or multiple time slot that is assigned to CAU in inserting acknowledgement message.Assign and/or allocated channel according to following rule.

1. the time slot on appointment and SBC and the SAC same carrier wave at first.CCU always attempts these channels are navigated on the good carrier wave.Further, system can ask based on ALT, learn the problem relevant with SBC and SAC from other channel of same carrier wave.

2. before moving on to another carrier wave, the available time slot on the carrier wave will be assigned.CCU loads ripple to improve the efficient and the probability of carrier link conversion with package.

3. when CCU began to assign time slot on new carrier wave, it will select to have the carrier wave of best in quality.

In case assigned channel, CAU will turn back to the carrier wave of being assigned, and CAU will use the time slot of being assigned to carry out the transmitting-receiving of Call Supervision Message to set up call or connection.Channel Assignment carries out at the first term of priority queue.

Each coverage is inserted the request priority queue with an independent system and is associated.Mistake often occurs in CAU attempt to reconnect the transfer of data of receiving a new carrier wave from effective carrier wave during.When CAU loses on descending carrier when synchronous, this carrier wave conversion takes place.Lose synchronously usually as the word error order report on the up-link carrier that mails to CCU.Receive after the word error indication, CCU carries out down link from affected carrier wave and is transformed into a new carrier wave.Figure 16 is the diagram that causes success to reconnect inserting signal between the CAU of request and the CCU.CCU will be in order that send to carry out reserve link conversion (ALT), during ALT-EXEC, no matter whether CAU receive ALT-EXEC, hang up this data link and encryption (if active (.ALT is used for although the frequency of channel changes, still keeping the process of the connection between the communication unit when calling is just being carried out.When receiving the request of reconnecting, RECON-ACCESS, CCU will assign CAU to give identical CPX efficiently, and this CPX is sending new descending carrier.After assigning new channel, CCU will send a busy pattern in the slow channel of new link, and send one to the CAU of the new channel of identification and insert and confirm response.CAU arrives new Traffic Channel with retuning, and recovers this data link.Identical initial access protocol timer and parameter will be applied to this and reconnect access procedure.

Referring now to Figure 17,, shows the CAU that reconnects the request of inserting that leads to the failure and the signaling diagram between the CCU.When this situation occurs in CCU and can not reconnect CAU.Like this, ask when CAU receives in response to its access that reconnects, when the admission reject of RECON-ACCESS responds, this CAU will send initial an access and ask to obtain a TCH of appointment newly.If this reconnects the request of access and requires a plurality of connections, then need to connect the different initial access request that sends for each.Influence to the user is that they may be disconnected in original calling, in this case, should provide dialing tone to the user when setting up new the connection.

In addition, CAU can use multi-thread being linked in the communication system in some cases, and multi-thread CAU can use the TCH of the active call that it controls to ask the access of an additional calls.There is not competition in TCH for having been used by the CAU that asks.As its result, competition can not appear in this channel, and does not need SUB, because carried out time calibration.Like this, only need to send initial an access on the Traffic Channel enlivening, one is inserted and confirms and access-reject message.These slow channel strips at time slot send.Figure 18 shows the process of the additional calls request access that is used on the slow channel.Referring to Figure 18 as can be seen, access procedure is started by CCU.Lose synchronously if having a plurality of CAU that enliven Traffic Channel, then all from the CAU are enlivened Traffic Channel and are carried out signal and reconnect process.Traffic-channel assignment during access confirms to respond is one by one corresponding to the Traffic Channel that reconnects appointment in the request of access.If in response to the request of access that reconnects of a plurality of Traffic Channels, receive an admission reject response, this CAU will send single initial access request for each Traffic Channel.

Can be in the processing shown in Fig. 6-7 and the 9-19 by those of skill in the art at Fig. 1, realize in the hardware shown in 2 and 3.Processing of the present invention also can be in above-mentioned hardware, is realized by a kind of program storage device that processor is readable, wherein the program storage device executable instruction of processing of the present invention of encoding.Program storage device can take various forms, includes but not limited to, and hard disk drive for example, CD, ROM, EPROM or RAM, these are all known those of skill in the art.

The processing that is stored in the program storage device is hidden, and up to passing through processor, for example microprocessor or DSP use this program storage device to activate.For example, the process that is provided to the access of communication system can be encoded into instruction, is stored on hard disk drive or the CD.Connecting this hard disk drive or this CD in CCU carries out these instructions and controls to the access of communication system to processor permission processor.In addition, the processing that is used for handling the competition of identical time slot between the CAU can realize that wherein when ROM was connected to this CCU, this processing became active state at ROM.

The present invention provides a kind of improved communication system by being provided for one group of independent channel of access communication system.These SAC are different from the TCH that is used for user profile, for example digital voice data.These SAC can be according to the transmission quality travel frequency.SBC provides one to be used for the SAC of access communication system and the table of their position.When receiving a TCH request on SAC, CCU gives a traffic-channel assignment according to available resources the CAU of request.This appointment sends to CAU on descending SAC.In addition, the invention provides a kind of CAU and be used to detect and solve the method for attempting the conflict between a plurality of CAU that send pulse train on the identical time slot.As its result, the method and apparatus of the invention of current statement allows improved system access communication system.

Though especially illustrate and described the present invention with reference to a kind of preferred embodiment, those of skill in the art will understand, under prerequisite without departing from the spirit and scope of the present invention, the different variation can be arranged in form and details.

Claims (7)

1. the method for solution transfer of data conflict in communication system comprises step:

Be used for sending first transfer of data from communication unit to the basic communication unit on the up channel of access communication system, wherein first transfer of data comprises a synchronous mode;

The monitoring down channel is to find the response from the basic communication unit, and wherein this response is associated with first transfer of data;

By checking this response, judge between first transfer of data and second transfer of data, whether conflict to have taken place from another communication unit, conflict had taken place in indication when wherein this response can not detect synchronous mode in the basic communication unit; And

In response to the judgement that conflict has taken place, after a random time section, retransmit first transfer of data automatically.

2. a communication system comprises

A cable distribution network;

A basic communication unit that is connected to cable distribution network, this basic communication unit produces downlink data transmission and receives transmitting uplink data;

Be connected to a plurality of subscriber communication units of cable distribution network, the basic communication unit of these a plurality of subscriber communication units in this cable distribution system sends transmitting uplink data, be linked into this communication system with request, the transmitting uplink data that wherein comes from a subscriber communication units in these a plurality of subscriber communication units is associated with the downlink transfer that this basic communication unit is sent to this subscriber communication units, and wherein each transmitting uplink data comprises a synchronous mode with each downlink data transmission;

This basic communication unit monitors is from the transmitting uplink data of a plurality of subscriber communication units, and in response to relevant downlink data transmission of each transmitting uplink data transmission, each downlink data transmission comprises whether this basic communication unit of indication can successfully receive the error indicator of this transmitting uplink data, and

Each subscriber communication units in a plurality of subscriber communication units is in response to a relevant downlink data transmission that receives from the basic communication unit, wherein the indication of the error indicator in the downlink data transmission can't successfully receive this transmitting uplink data, after one period at random, resend a transmitting uplink data.

3. a subscriber communication units comprises

One adapts to the interface that is connected to the cable distribution network in the communication system; And

A processor that is connected to this interface, wherein this processor has multiple mode of operation, comprises

First mode of operation, wherein processor sends first transmitting uplink data from subscriber communication units to the basic communication unit, sends in the time slot in the frame of first transmitting uplink data in a superframe;

Second mode of operation, wherein processor receives a relevant downlink data transmission relevant with first transmitting uplink data, and the downlink data transmission of wherein being correlated with is associated with first transmitting uplink data by being received in the corresponding time slot of follow-up superframe and frame;

The 3rd mode of operation, wherein processor judges between first transmitting uplink data and another transmitting uplink data from another communication unit whether conflict to have taken place by checking the error indicator in the relevant downlink data transmission; And

The 4th mode of operation, wherein processor after a random time section, is retransmitted first transmitting uplink data in response to the judgement that mistake has taken place automatically.

4. the readable and coding of the processor in the communication unit is used for the memory device of the processor executable of processing data collision, and this memory device comprises:

Be used for sending first command device of first transmitting uplink data from subscriber communication units to the basic communication unit, wherein the first transmitting uplink data request is linked into communication system;

Be used for receiving second command device of relevant downlink data transmission from the basic communication unit;

Be used for by checking the error indicator of relevant downlink data transmission, judge whether the 3rd command device that conflicts has taken place between first transmitting uplink data and another transmitting uplink data from another communication unit; And

Be used in response to the judgement that mistake has taken place, after one section random time, retransmit the 4th command device of first transfer of data automatically, wherein when storage device was connected to processor, this command device was activated.

5. communicator that uses in cable communication system comprises:

One adapts to the interface that is connected to the distributed network in the cable communication system, be provided on distributed network, the transmitting and receive data connection of transmission of this interface, wherein on a plurality of channels, send transfer of data, each channel is assigned the part of wireless frequency spectrum, and wherein this part of wireless frequency spectrum is divided into a plurality of time slots by the time; And

Be connected to a receiver of this interface, wherein this receiver receives the modulated data signal from this interface, and converts modulated data signal to numerical data;

Be connected to a transmitter of this interface, wherein this transmitter converts the digital data into the modulated data signal that sends to communication system;

Be connected to this transmitter and connect a processing unit of device with this;

Adapt to a local loop interface that is connected to subscriber equipment; And

Be connected to a pulse code modulated codes/decoder element of this transmitter processing unit and local loop interface, the numerical data that wherein comprises user data is converted into analog form and uses for the user, and wherein the analogue data from the user is converted into digital form

Wherein processor sends first upstream bursts to the cable control unit, and wherein first upstream bursts is positioned at a time slot of a frame of a superframe, and first transfer of data comprises a synchronous mode; Receive a relevant downstream pulses string with the cable control unit, wherein relevant downstream pulses displacement is in follow-up superframe in time slot corresponding and the frame; By checking the error indicator in the relevant downstream pulses string, judge between first upstream bursts and another upstream bursts whether conflict has taken place from another communication unit, wherein when the cable control unit can not be discerned synchronous mode, the error indicator indication conflicted; And, after one section random time, resend first upstream bursts in response to the judgement that conflict has taken place.

6. equipment that uses in cable communication system comprises:

One adapts to the interface that is connected to the distributed network in the cable communication system, this interface is provided at the connection of the transmission of reading to transmit and receive data on the distributed network, wherein on a plurality of channels, send transfer of data, each channel is assigned a part of wireless frequency spectrum, and wherein this part wireless frequency spectrum is divided into a plurality of time slots by the time; And a processing unit, comprise

Be used for sending to the basic communication unit first processing unit of first transmitting uplink data, wherein first transfer of data is arranged in a time slot of a frame of a superframe, and first transmitting uplink data comprises a synchronous mode;

Be used for receiving from the basic communication unit second processing unit of relevant downlink data transmission, wherein relevant downlink transfer is arranged in the corresponding time slot and the frame of follow-up superframe;

Be used for by checking the error indicator of relevant downlink transfer, whether judgement the 3rd processing unit of conflict has taken place between first transmitting uplink data and another transmitting uplink data from another communication unit, indication conflict when wherein error indicator can't successfully receive first transmitting uplink data in the basic communication unit; And

Be used in response to the judgement that conflict has taken place, after one section random time, resend the of first transmitting uplink data and manage device everywhere.

7. communication unit that uses in cable communication system comprises:

Adapt to an interface that is connected to distributed network in the cable communication system, this interface is provided at the connection of the transmission that transmits and receive data on this distributed network, wherein on a plurality of channels, send transfer of data, each channel is assigned a part of wireless frequency spectrum, and wherein this part wireless frequency spectrum is divided into a plurality of time slots by the time; And

Processing unit with multiple work post pattern, a plurality of mode of operations comprise:

First mode of operation, wherein processor sends first transmitting uplink data to the basic communication unit, and wherein first transmitting uplink data is positioned at a time slot of a frame of superframe, and first transmitting uplink data comprises a synchronous mode;

Second mode of operation, wherein processor receives a relevant downlink data transmission from the basic communication unit, and wherein relevant downlink data transmission is arranged in the corresponding time slot and the frame of follow-up superframe;

The 3rd mode of operation, wherein by checking the error indicator in the relevant downlink transfer, whether judgement between first transmitting uplink data and another transmitting uplink data from another communication unit conflict has taken place, indication conflict when wherein error indicator can't be discerned synchronous mode in the basic communication unit; And

The 4th mode of operation, wherein processor after one section random time, resends first transfer of data in response to the judgement that conflict has taken place.

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