CN1179252A - Channel quality management in a cable telephony system - Google Patents

Channel quality management in a cable telephony system Download PDF

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Publication number
CN1179252A
CN1179252A CN 96192741 CN96192741A CN1179252A CN 1179252 A CN1179252 A CN 1179252A CN 96192741 CN96192741 CN 96192741 CN 96192741 A CN96192741 A CN 96192741A CN 1179252 A CN1179252 A CN 1179252A
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China
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channel
quality
cable
channels
communication system
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阿兰·I·格鲁
里查德·J·考里甘
库特·W·斯坦布莱那
蒂默斯·布克
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Motorola Solutions Inc
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Motorola Inc
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Priority to CN 96192741 priority Critical patent/CN1179252A/en
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Abstract

A method and apparatus in a communication system (100) for allocating and controlling data transmissions to and from communications unit (134) in communications system (100). The communication systems (100) includes a cable distribution network (106) with a 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 transmissions between the base communications unit (100) and the downstream communications unit (134). Uplink and downlink channels are monitored to determine channel quality for each of the channels in communications system (100). The determined channel quality is used to both initiate transfers of communications links to other frequencies and for assigning channels to various communications units (134).

Description

Channel quality management in the cable telephony system
The present invention relates to communication system, particularly relate to the method and apparatus of management channel in the communication system.Say that more particularly the object of the invention is to propose a kind of method and apparatus, this method and apparatus is used at cable telephony system, by measuring all channel qualities and distributing all channels according to the measurement result of channel quality, comes the management channel quality.
Communication system, for example cable communication system (cable communications system) utilizes one or more radio-frequency channels that transfer of data is provided.During the transfer of data of all communication units of communication system, the appearance of disturbing on a certain characteristic frequency may be unexpected, and may be catastrophic, makes characteristic frequency (also being called " channel ") become disabled.Furtherly, in single incident, can cause interference by a logarithm channel with the interference of invading the appearance of noise (ingress noise) form.Such intrusion noise or interference can be caused by the radiation of equipment (for example commercial formula industrial equipment) of wireless system (for example cellular system) and other type.
In addition, the various communication units of employing cable communication system may need the channel quality of different brackets, and this depends on the data transmission that they adopt.For example, the data transmission ratio that is used for the interactive multimedia service carries the higher channel quality of transfer of data requirement that common simulated voice is talked.Therefore, may be acceptable by the interference in the channel that a certain communication unit adopted, and same interference be unacceptable for another communication unit.
Therefore, the method and apparatus of grasping a kind of definite channel quality should be useful, so, just can avoid interference, and can carry out channel allocation according to channel quality.
In subsidiary claims, proposed it is believed that features of novelty into feature of the present invention.Yet, when related accompanying drawing is read together,, will understand the occupation mode of the present invention itself and a kind of the best, its all purposes and all advantages better by detailed description with reference to following illustrated embodiment.Wherein,
Fig. 1 is the schematic diagram that can implement communication system of the present invention;
Fig. 2 A is the block diagram of the parts in the cableport transceiver (CPX) in the cable control unit (CCU);
Fig. 2 B is the block diagram of each parts in the controller of CCU;
Fig. 2 C is the block diagram of each parts in the control unit of cable access units (CAU);
Fig. 3 is the graphic extension of the spectrum allocation may of communication system;
Fig. 4 A is a superframe (superframe) figure;
Fig. 4 B is the graphic extension of CCU channel and CAU channel;
Fig. 4 C is the figure of the pulse train (burst) from the downlink control channel of CCU to CAU;
Fig. 5 is the flow chart that obtains this process of power attenuation level from a signal that receives at the cable control unit;
Fig. 6 A is a channel quality level figure;
Fig. 6 B is traffic carrying capacity (TCH) sequencing table in the credit rating table;
Fig. 6 C describes in response to receiving new quality metrics ordering (QM-R) report, how to change channel record and distributes;
Fig. 6 D is a channel record figure in the channel quality level table;
Fig. 7 is in the supervisory communications, for example the high level flow chart of all this processes of TCH of the communication system among Fig. 1 100;
Fig. 8 is the state diagram of a CPX;
Fig. 9 is a flow chart that idle CPX handles;
Figure 10 is the flow chart that a line is busy CPX handles;
Figure 11 is the flow chart of the process of distribution service channel;
Figure 12 is a flow chart of a channel allocation being given the process of CAU; And
Figure 13 is CAU request and the flow chart that is assigned with the process that a Traffic Channel follows.
The present invention proposes a kind of method and apparatus that the acquisition channel quality is measured in communication system, and a kind of method and apparatus of managing all channels according to the quality metrics that is obtained.In a wire-telephony system, for uplink channel, the line is busy and idle condition under record quality metrics, and, under engaged condition, record quality metrics for downlink channel.As what adopted in this description, " up link " refers to the information that a subscriber unit from the zone is launched to cable head (headend), and " down link " refers to from the information of (all) subscriber unit emission of head end to the zone.Quality metrics is the measurement of radio frequency (RF) quality of signals of a channel.The initialization of the sign of channel quality, channel (link) transmission and the distribution of Traffic Channel are the quality metrics that records according to these.Following description is from explaining environment of the invention process.Then, this description is stated all types of measured quality metrics and how to be used these quality metrics according to the present invention.After this, proposed in a communication system, to obtain the explanation of the related all processes of quality metrics and management channel.
Environment
Referring now to all figure, particularly with reference to Fig. 1, it has represented a communication system 100, can implement the present invention in this communication system.Communication system 100 is examples of a kind of basic cable system structure, and this cable system structure is a kind of combination that utilizes optical fiber and coaxial cable to the client compound cable system of devices allocation user service within doors.On the other hand, communication system 100 can comprise whole coaxial cable and other configuration.Regardless of the construction of cable, cable branch will be served the distributed areas of being shared by all user's community.In described example, communication system 100 is the wire-telephony systems that telephone service and cable television services are provided on coaxial optical fiber cable TV basic structure.
Communication system 100 comprises that a cable control unit (CCU) 102 or some other are connected in user 104 basic communication unit by distributed network 106 and combiner 108.Combiner 108 has 110 inputs of a video source.CCU102 also comprises all cableport transceivers 112 that link to each other with combiner 108.In communication system 100, these cableport transceivers produce all descending (downstream) carrier channel.The all CPX of combiner 108 from all video source 110 and CCU102 receives all modulated RF channels, and these signals that send on distributed network 106 are accumulated in together.Control all CPX112 by a controller 114, this controller provides all necessary functions of data link part of supporting this system.Head end generally comprises CCU102, combiner i08 and video source 110.Digital switch 116 may be remote apart with head end, perhaps is positioned at head end itself.These parts are head end device that a responsible cable branch road in communication system 100 provides access and Service Management.Controller 114 among the CCU102 is by digital carrier frequency equipment, and for example T1 or the E1 that links to each other with PSTN (PSTN) 118 successively links to each other with switch 116.For example, switch 116 can be 5 grades of remote controls (TELCO) switches.
Make transmission become more convenient by downlink optical fiber main line 120 and uplink optical fibers main line 122 from the CCU102 in the distributed network 106.These optical fiber main lines are fiber optic cables, and are connected to Fiber Node 124.In distributed network 106, the orientation conversion between the light territory of Fiber Node 124 realization fiber optic cables and the electric territory of coaxial cable.Each Fiber Node 124 have one with being connected of at least one cable branch 126.In described example, cable branch 126 is made up of coaxial cable, and comprises all relay amplifiers 128, and these relay amplifiers are the two-way amplifiers in the described example.In addition, all bidirectional line expanders (extender) 130 be positioned all taps (taps) 132 near, tap 132 is connected to all cable access units (CAUs) 134 that are positioned at user 104.These CAU also are called as " subscriber communication units ".Every cable branch 126 comprises one or more coverages.
In communication system 100, CCU102 is used to provide phone, Integrated Service Digital Network service, digital video, interactive video or interactive multimedia etc.In addition, CCU102 control cable frequency spectrum, basic structure resource and to the service of all CAU in a coverage, and manage a plurality of coverages.All CAU134 provide phone, ISDN, digital video, interactive video, interactive multimedia and television services at the CPE place.Generally, CAU is installed in a side of user's house, perhaps certain unobtrusive place, for example basement or loft.This CAU management up link and downlink communication paths, and to user's transmission of television cable TV channel.
All cable access units, for example all CAU134, the scanning down link is with the frame synchronization of acquisition with system broadcast channel (SBC).Optimizer system adopts the time division multiple access scheme, this means that each RF carrier frequency is divided into several time slots, each time slot is used as a channel, for example, SBC, a Traffic Channel (TCH) or a system cut-in channel (SAC), just as described further below like that.SBC takies a time slot in one of all channels of each cable branch of cable communication system.Utilize known digital correlation to handle and obtain frame synchronization.System cut-in channel (SAC) and Traffic Channel (TCH) also are used in the time slot.All SAC are used to ask access network and are used to carry out TCH distribute.All TCH are the channels that carries the needed all calls of user or other data communication.
Next please see Figure 2A, this figure is the block diagram of all parts among the CPX who describes according to the present invention in the CCU102.CPX112 comprises upstream bursts receiver 202, analog/ digital converter 204 and 206, up DSP208, microprocessor 210, descending DSP212 and downstream transmitter 214.
In CPX112, upstream bursts receiver 202 receives time division multiple access (TDMA) pulse train from CAU, and is this pulse train down conversion base band quadrature I and Q signal." pulse train " is the constant transmissions of the number of bits certificate of beared information.This pulse train is subjected to the PI/4-DQPSK modulation.Utilize mould/number (A/D) converter 204 and 206 that these baseband I and Q signal are transformed to digital signal, and utilize digital uplink signal processor (DSP) 208 that they are handled.In described example, A/ D converter 204 and 206 is 8 A/D converters.The information that up DSP208 sends after handling to microprocessor 210.In addition, a microprocessor in the controller of in Fig. 2 B, describing in more detail below microprocessor 210 is connected to 114.Up DSP208 sends it back controller 114 to pulse-code modulation (PCM) information on a up PCM HW highway bus, descending DSP212 receives PCM information via descending PCM HW highway bus slave controller 114 simultaneously.
Microprocessor 210 sends it back CAU to message by being positioned at descending DSP212 and the descending TDM transmitter 214 that communication network wherein links to each other with CAU.Microprocessor 210 also sends and all senior messages of slave controller 114 receptions to controller 114 by communication bus 220, for example control information.
Among the CPX112 in Fig. 2 A, up DSP208, microprocessor 210 and descending DSP212 have formed a processing unit.This microprocessor among the CPX112 and all DSP have constituted the part of the processing unit among the CCU102.
Next please see Figure 2B, this figure be one according to the present invention the block diagram of the controller among graphic extension Fig. 1.Controller 114 comprises line interface 224, time slot interchanger 226 and microprocessor 228.Line interface 224 provide one with Fig. 1 in the communication interface of digital switch 116, this digital switch can be a local digital switch by T1/E1 interface 230.In addition, controller 114 is each CPX by communication bus 232 and microprocessor 228 also, and for example all CPX112 in the CCU102 provide controlled function.
Say that clearly the PCM signal is by Time Division Multiplexing, and be grouped together in the sequence time slot on all T1/E1 signals that line interface 224 places receive.In line interface 224 these signals are deciphered, and they are decomposed in each time slot of PCM data, send to time slot interchanger 226, this time slot interchanger provides cross point switches between the input and output of oneself." mapping (mapping) " of all I/O time slots of microprocessor 228 control, subsequently the I/O time slot focused on each HW highway PCM data/address bus 232 that all CPX among the CCU link to each other in.Say especially, adopt PCM HW highway data/address bus 232 that time slot interchanger 226 is connected on the up DSP208 and descending DSP212 among Fig. 2 A.
Microprocessor 228 control circuit interfaces 224 and time slot interchanger 226.In addition, microprocessor 228 utilizes communication bus 234 to send control information to all CPX.More particularly, the microprocessor 228 among Fig. 2 A has being connected via the microprocessor 210 among bus 234 and Fig. 2 A.
Referring now to Fig. 2 C,, this figure is a block diagram of describing all parts among the CAU134 according to the present invention.Hybrid coaxial cable in the distributed network 106 among CAU134 and Fig. 1 is linked to each other with control 252 by the RF interface, this RF interface provides an interface of 75 ohm with hybrid coaxial cable with controlling.The RF interface also provides being connected the cable TV equipment on the CPE with control 252.In addition, RF interface and control 252 comprise a control switch, are used for turning on and off the signal of all cable television systems that flow to the CPE place.Be addressed to digital receiver (demodulator) 254 from RF interface and the data that the CCU that controls 252 receives there.The all signals that receive from CCU are in the frequency range of about 50MHz to 750MHz, and are converted to low intermediate frequency (IF) by digital receiver 254.From this form, digital receiver 254 is converted to a base band π/4 DPQSK modulated signals to low frequency IF.Next, this signal of rectification is to obtain bit from this signal.After this, data/clock recovery device 256 carries these bits from digital receiver 254, and these bits are decomposed, and sends to processing unit 258 or pulse-code modulation (PCM) encoder/decoder (codec) 260.Control information is addressed to processing unit 258, and user data is addressed to PCM volume/decoder 260 simultaneously, and this volume/decoder is converted to analog form to user data.
In described example, processing unit 258 comprises one or more microprocessors and random access storage device (RAM) and read-only memory (ROM).Be included as microprocessor in the processing unit 258 or the performed process of all DSP among RAM and the ROM and coded data and instruction.By PCM volume/decoder 260 user profile is converted to analog form, and they are sent to local loop interface (SLIC) 262.SLIC262 provides the basic telephone function, for example shows that a certain phone is ring or on-hook, and perhaps whether loop is closed (loop closure) occurs.In addition, SLIC262 is separated into one to all duplex signalings and sends signal and a received signal.SLIC262 and all functions of being finished thereof are well-known to those skilled in the art.In fact ring generator 264 provides the voltage that is used to make phone ringing.
Subscriber signal from CPE is sent out back PCM volume/decoder 260 by SLIC262, and PCM volume/decoder is transformed to digital form to these data from analog form, is used for handling for emission data framer (transmit data framing) 266.Emission data framer 266 is put into the pulse train that is transmitted to CCU with original voice data and these data.For example, emission data framer 266 comprises required synchronizing information, and calculates the loop redundancy encoding (CRC) that is used for error detection, and this coding is placed into the error code part of tdma frame.Emission data framer 266 is subject to processing the control of unit 258, and transmission and the synchronous all signals of downlink transmission.It is synchronous to control in the emission data framer 266 this by data/clock recovery device 256.In other words, travel to and fro between the up link of CAU134 and downlink transmission by synchronously.At last, data are mail to RF interface and control 252 as a pulse train, and beam back CCU as a ul transmissions by digit emitter (modulator) 268.
Among Fig. 1 on distributed network 106 data carried by data can comprise speech and non-voice data, for example Integrated Service Digital Network, digital video, phone data, interactive video or interactive multimedia business.In the present invention, the conveying technology that adopted of the telephone reciprocal exchange of business is by relaying.In other words, a telephone Traffic Channel is not exclusively used in a specific user, but according to a service request, all users can use above-mentioned Traffic Channel.This allocative decision is called as multiple access or local loop is concentrated.
Generally, in case a certain particular channel is assigned to a user, for the duration of calling out, this channel has been assigned with so.If user's interim distribution is so just cancelled in end call, and for a thing followed service request, this channel becomes available.The result is, compares with channel quantity available in the cable branch, and CCU might serve more users.In addition, for the different user groups in every cable branch of cable system, can be adopted as the frequency spectrum that CCU distributes.
According to the present invention, the employed radio frequencies of a plurality of users of wire-telephony system divides (RF) frequency spectrum so, does not exist the individual user to occupy the situation of a dedicated frequency scope.With reference to Fig. 3, this figure is a schematic diagram of describing the spectrum allocation may of communication system 100 according to the present invention.Different user's group that can be distributed for the frequency spectrum that service distributed in the individual cable branch in each cable branch of network 106 reuses.In described example, RF spectrum 300 comprises uplink spectrum 302 and downlink spectrum 304.In described example, the scope that uplink spectrum 302 covers from 5MHz to 42MHz, downlink spectrum 304 coverings simultaneously are from the scope of 50MHz to 750MHz.These frequency spectrums further are divided into bandwidth and respectively are all channels of 6MHz.In described example, downlink spectrum 304 comprises that each channel width is 120 channels of 6MHz.Although described example has been represented channel width and has been 5 to 42MHz the uplink spectrum of 6MHz and 50 to 750MHz downlink spectrum 304, can adopt other frequency spectrum and channel width according to the present invention.
Communication system 100 is divided into all zones with independent signal path, and in each zone, different user's group that can be distributed for the frequency spectrum of telephone traffic assignments in every cable branch of network 106 reuses.In downlink spectrum, great amount of conventional television channel (for example bandwidth is 80 channels of 6MHz) is transferred into the cable TV user.On the contrary, in uplink spectrum, provide other communication.An equal or bigger part of the part of downlink spectrum and uplink spectrum is dedicated to a plurality of junction traffic channels, and these channel services are in a large number of users with phone and/or other two-way services.In these special-purpose spectrum allocation may, a large amount of RF channels have been adopted.The spacing of these RF interchannels is 600KHz, and each channel comprises 8 digital coding time division multiplexing information of Bearer Channel.A channel in the uplink segments of all active channels and distribution is worked in pairs, and each channel in the uplink segments is relevant with each channel in the down link section.This association is used for Frequency Division Duplexing (FDD) (FDD) operation.
In addition, communication system 100 provides time division multiplexing, by the access to media is divided into sequence " time slot ", derives a lot of channels from emission medium.As reference Fig. 4 A can see, superframe 400 comprises that every frame has 8 frames of 8 time slots.Next 4B with the aid of pictures, CCU channel 402 comprises frame 404 and 406, CAU channel 408 comprises frame 410 and 412 simultaneously.Each frame has 2.5 milliseconds length, is divided into 8 time slots, has constituted the digital coding Time Division Multiplexing information of 8 Bearer Channels.
For the used different signaling type of communication unit, each time slot is by further subregion.For example, the downlink bursts 414 in the time slot 1 in the frame 406 comprises 422 and error control channels of 420, Fast Channel of 418, slow channel of 416, control channels of a synchronizing channel (SYC) (CC) (SC) (FC) (EC) 424.SYC416 is a synchronizing channel that is used for frame synchronization.CC418 is used to indicate word error, signaling and power control.SC420 is used for signaling, and FCC422 is used to user data and signaling.EC424 is used for error detection occurs.
Uplink burst 426 in the time slot 2 in the frame 412 comprises differential encoder bit (DE) 428, synchronizing channel (SYC) 430, CC432, SC434, FC436 and EC438.SYC416 in the downlink bursts 414 comprises 25 bits, and the SYC430 in the uplink burst 426 comprises 14 bits simultaneously.CC418 in the downlink bursts 414 comprises 9 bits, and the CC432 in the uplink burst 426 comprises 2 bits simultaneously.SC420 and SC434 comprise 26 bits.Downlink bursts 414 comprises altogether 240 bits and time span is 312.5 milliseconds, and uplink burst 426 comprises 224 bits and time span is 291.67 milliseconds simultaneously.In uplink burst 426 and downlink bursts 414, SC comprises 26 bits, and FC comprises 160 bits, and EC comprises 20 bits.
According to the present invention, it is the downlink channel of launching between the 50MHz to 750MHz in frequency range that CCU channel 402 is one, and it is the uplink channel of launching between the 5MHz to 42MHz in frequency range that while CAU channel 408 is one.Transfer of data in these channels is used as one " pulse train " and sends, and should " pulse train " be the transfer of data of a fixed length, for example transmission of one group of bit.In described example, in CAU channel 408, pulse train is 224 bits of each time slot, and in CCU channel 402, pulse train is 240 bits of each time slot.
Referring now to Fig. 4 C, this figure is a schematic diagram of describing the pulse train from the downlink control channel of CCU to CAU according to the present invention.Downlink bursts 440 on the throne 1 puts in place and comprises a Hyper Frame Number in 3, represents which frame in 8 sequence frames is formed a superframe.On the throne 1 to position 3, these frames by from 0 (" 000 ") to 7 (" 111 ") mark periodically.This value is identified at the position of a certain frame in this superframe, is referred to as frame number.Just as seen, least important bit in the frame emission at first.Position 4 to position 6 marks in the control channel the time slot in a certain given frame.These time slots by from 0 (" 000 ") to 7 (" 111 ") sequence notation.At first launch least important bit.According to the present invention, reservation bit item 7 is for using from now on.No. 8 bits are word error indicating devices, when error occurring it are set at " 1 ", when error not occurring, it are set at " 0 ".No. 9 bits in the downlink bursts 440 are Fast Channel indicating devices, and it shows whether this Fast Channel comprises signaling information or user profile.
Each time slot in up link and downlink transmission is used to various types of channels, for example system broadcast channel (SBC), system cut-in channel (SAC) or Traffic Channel (TCH).SBC and SAC are system channels.All SBC monitor the CAU broadcasting system information of all SBC to all in downlink transmission.CAU location SBC also intercepts SBC, to obtain to mail to the general information of interest of all devices that is attached to CAU.According to the present invention, system banner device and ability that the SBC sign is general; The security information that is used for authentication and encryption; And the location of all channel frequencys, all SBC and all SAC.In communication system, it is redundant that multiple SBC is used to provide.
Adopt SAC to come access communication system 100 by CAU.As a result, CAU is assigned with a TCH, carries out signaling protocol with this TCH.When CAU of registration, will regain SBC and listen to the notice that inlet is called out.
SAC is a physical channel, adopts this channel to obtain to enter communication system and obtain a TCH, or reconnects to a TCH.Competition between a plurality of CAU that adopt multiple SAC to provide redundant also minimizing requirement to enter communication system 100 ask.All TCH provide the user to serve in communication system 100, and for various message transmission rate, can ask and distribution T CH.These TCH or (in the use) or idle (not the using) that the line is busy.
Communication system 100 comprises the device of handling the interference in the distributed network 106 that appears among Fig. 1.The generation of disturbing on a certain characteristic frequency may be unexpected, and may be catastrophic, channel is become can not use fully.A kind of device is provided in communication system 100, has been used to detect the appearance of interference, and switched to another channel to avoid interference.Handoff procedure from a channel to one other channel is regarded as a kind of optional link transmission (ALT).In addition, communication system 100 also comprises a process, is used for giving various CAU all traffic channel assignments according to the channel quality in the communication system 100.
Quality metrics
Quality metrics is used to measure channel quality, distributes all channels and triggers all ALT.According to the present invention, word error, signal to noise ratio (snr) and relative power level decay (ARPL) value are quality metrics detected and that measure.On the uplink channel that the line is busy, measure SNR, word error and ARPL value, on all downlink channel that the line is busy, measure word error.Represent the downlink quality defective that the line is busy by the word error report in the corresponding uplink channel.According to the present invention, on the uplink channel of free time, measure the relative power level pad value.These quality metrics are used to determine when implement an ALT.Quality metrics also is used in to be determined channel quality and is all channel orderings in the communication system.These channel orderings are used to all channels of the desired mass distribution of CAU according to the request channel.
The quality metric that is in outside the acceptable scope is a mass defect, and is used to confirm the generation of upcoming disturbing pulse string, and triggers ALT to avoid interference.Mass defect is also referred to as " quality metrics defective " (QM-D).But this channel switching causes temporary transient quality to descend.As a result, the number of effective ALT should be minimized.Further, in case ALT is implemented, before can implementing another ALT, must pass a certain amount of time.The result is, should be done as the original allocation of the channel of the target of all ALT and the selection of channel, to reduce to take place the possibility of ALT to greatest extent.
Quality metrics ordering (QM-R) value is a value that the measurement (decay is average) of the history of channel quality is provided, and then, this value is used to when select one to be used to distribute or as the channel of the target of ALT in available all interchannel differentiations.
In communication system 100, the present invention carries out related with every channel a QM-R value.By all DSP in all CPX112 collect all quality metrics usually, and they are delivered to controller 114.These data are used as the standard of selecting a Traffic Channel that is used to distribute.
Word error
Word error occurs at detecting, each tdma frame comprises a mistake channel and a word error indicating device (WEI).This mistake channel comprises a loop redundancy check (CRC).Set the WEI position by CAU or CPX, to send signal announcement: by having detected a mistake in the former pulse train of inefficacy CRC.
When receiving a pulse train in the given frame of a CAU at down link, the down link word error is determined.CAU formally draws up the right value of WEI position, and its is inserted in uplink burst, and this pulse train is to send in corresponding time slot in next superframe and the frame.When receiving a pulse train in the given frame of a CPX in up link, the up link word error is determined, and CPX checks that CRC occurs to determine whether word error subsequently.If detect word error, WEI is set so.
The relative power level decay
All CPX among CCU signal strength signal intensity that measurement receives in each time slot (movable or idle).Before signal limiter, this received signal volume indicator (RSSI) measured signal power, and be calibrated so that the decibels of the signal attenuation of importing with respect to the maximum linear of receiver to be provided.Value after this calibration is called as relative power level decay (ARPL) value.The emission CAU burst power level that the ARPL readings signify of a 0dB receives is in maximum level.Any increase of CAU power will cause distorted signal to be received.The reading of a 6dB shows that the burst power that receives is than the low 6dB of maximum level.In described example, ARPL has the dynamic range of a 40dB.
With regard to the ARPL quality metrics, measure although on the pulse train that receives on all TCH, make ARPL, also on all TCH of idle up link, collect the ARPL quality metrics.For the management of all channels that occur disturbing, the measurement of the ARPL on all channels of idle up link is useful characteristics.Say especially, compare that in up channel, invading noise is a more obvious problem (when interference appears on the channel, ALT will be implemented, and this channel is moved to idle condition) with down channel.If all idle channels can not be sorted, so just can not be to distributing or making the selection of a wisdom as the channel of the target of ALT.All ARPL are the power attenuation level that receives at the CCU place.According to the present invention, all ARPL measurements on all idle TCH on the uplink channel are used to detect the appearance of interference.
Referring now to Fig. 5,, this figure has described to obtain from a signal that receives at CCU the flow chart of the process of a power attenuation level according to the present invention.Even do not receive pulse train or signal from CAU at the CCU place, this process also can be used to measure all idle channels by the signal strength signal intensity of measuring time slot.A similar process also can be used to measure the power attenuation level at CAU place, with all ARPL values of all channels of down link that obtain that the line is busy.This process starts from receiving a complex digital signal (step 500) from all A/D converters.After this, recover symbol regularly (step 502), and calculate the vector magnitude (step 504) of this composite signal.Adopt a kind of compute vector amplitude that is similar to: | VEC|=I 2+ Q 2Approximation is in the formula | VEC|=0.3364*MIN (| I|, | Q|)+MAX (| I|, | Q|).The employing step (step 506) of tabling look-up is converted to a logarithm to the average vector amplitude of linear 7 place values.With respect to the maximum input of the preceding A/D converter of amplitude limit (step 508), this logarithm is represented attenuation with decibels in proportion, and after this this process stops.The ratio logarithm that is illustrated in the attenuation of determining in the step 508 with the decibel form is ARPL.By Burke, the common unsettled U.S. Patent application of Timothy M.et.al. application, be entitled as the information that can find more related detection in " method and apparatus of the adaptive RF power control of cable access units " literary composition and measure the power attenuation level, above-mentioned file was signed October 27 nineteen ninety-five, quoted for reference at this.According to the present invention ,+23dB is idle traffic (channel) interference threshold.In particular, the ARPL measurement of 0dB is the strong indication of disturbing, and+23dB is seldom or not have the indication of interference.
Signal to noise ratio
With regard to the SNR quality metrics, SNR determines to adopt the signal strength measurement receive, the ARPL measured value among Fig. 5 for example, on the CPX that distributes to an active channels frequency by all DSP each of active uplink channel the line is busy and idle time slot on collect above-mentioned measured value.
On movable time slot, the ARPL indicating device is measuring-signal plus noise power in fact.But in normal working conditions, signal power is far longer than noise power, and the effect of noise can be left in the basket.On an idle time slot, the ARPL indicating device is only measured noise power.Noise power reading (ARPL by idle channel Idle) and the signal plus noise power level readings (ARPL of active channels Movable) between difference determine the SNR quality metrics:
SNRdB=ARPL Idle-ARPL Movable
The ARPL of movable time slot is the ARPL reading of the TCH time slot of current distribution.The ARPL of idle time slot be with the same frequency of movable TCH on the ARPL reading of youngest idle time slot.ARPL IdleParameter is the variable of a monodrome corresponding to each CPX receiver, and this receiver is mixed be initialised (maximum attenuation level or 40dB) at each new upstream frequency branch, and is modified and safeguards in the calling duration, that is, be released up to upstream frequency.No matter when idle time slot appears on that frequency, revises ARPL with new ARPL reading IdleParameter.On that dividing frequency, this parameter is blanket to all movable time slots, and it is used to the calculating of SNR.
For example, suppose that a specific CPX is assigned to a new frequency F1 who has the related uplink channel, and suppose that single CAU is assigned to the time slot 7 of that channel.In this case, time slot 0 to 6 is idle.After CPX returns F1, ARPL IdleParameter is initialized to 40dB.Suppose that again the ARPL reading in all idle time slots is 24dB, this just means the maximum input low 24dB of the power level of noise than receiver.When receiving time slot 0, ARPL IdleParameter will become 24dB.Equally, for time slot 2 to 6, this parameter is modified.At last, when time slot 7 is received and the ARPL level of 5dB when being reported, calculate the SNR of time slot 7 with the result (24dB-5dB) of 19dB.
The technology of this estimation SNR depends on the density of traffic of allocated channel, and particularly all time slots are in the situation in the use.But, in this case, when determining link transmission, can adopt other channel quality to measure, for example pulse train CRC mistake.
Error log
For every frame, use a record to determine during the frame period of a channel, whether having occurred defective.For each up link and the downlink channel of distributing to a CPX have been preserved the record of 4 youngest mass defects.This record comprises clauses and subclauses of each time slot, and these clauses and subclauses comprise an indication that mass defect whether occurred.
CCU counts the wrong frame number that appears in 4800 frame windows (12 second cycle).If in 4800 frame windows, 2 continuous frames, or the frame of 4 or more a plurality of accumulations goes wrong, and carries out the link conversion so, moves to the new channel with less noise.Although described example adopts 4800 frame windows, and come initialization ALT, can use other frame size, and can adopt other mistake frame number to come ALT of initialization according to 4 that go wrong or a plurality of frame.
Mass defect at interval
Mass defect (QD-I) at interval is the interval that mass defect occurs.The quality metrics ranking value is the historical average of QD-I.Adopt the historical measurements of a decay average computation channel quality, method is as follows:
Old QD-I* (1-attenuation rate)+new this attenuation rate of QD-I* attenuation rate of QM-R=is the number between 0.0 to 1.0.If attenuation rate is 0.8, formula is as follows so:
The old new higher attenuation rate of QD-I*0.8 of QM-R*0.2+ of QM-R=causes QM-R to measure more being sensitive to current QD-I, and quickly in response to the variation of channel quality.Lower attenuation rate causes more stable QM-R to measure, and this measurement not too is sensitive to current QD-I, measures but more be sensitive to QM-R in the past.
Channel quality level
One group of channel quality is called as " channel quality level " and is supported, and the user can therefrom select a required channel quality level.Transfer of data or the COS that provides in the communication system is provided each group (channel quality).The data of different types transmission can be sensitive to channel quality more or less.The user can be a people who makes one's options, a CAU or a computer program, this program with data handling system that communication system 100 is connected on carry out.
Define each channel quality level by high and low QM-R value, this value has defined the scope of all QM-R values for this grade.All QM-R values of the number of the channel quality level of being supported and each channel quality level of definition depend on particular communication system and specific enforcement.
Referring to Fig. 6 A, this figure is the figure that describes the signal quality grade according to the present invention.Table 600 comprises 4 grades: 1 grade to 4 grades.Each grade in the table 600 comprises the QM-R value, also is referred to as " mass value ", scope between 0 to 9, the channel that 0 representation quality is minimum, the highest channel of 9 representation qualities.Each user can select it will preengage the channel quality level of (Subscribe).Each grade comprises a high-quality value and a low-quality value.Each request from CAU comprises a channel quality level according to the particular type of service of being asked.High-quality value is determined the preferred channel quality by user's request.The explanation of low-quality value is by the very poor channel quality of customer requirements.Certainly, person of skill in the art will appreciate that the number of levels or the value that can adopt other according to the present invention.
According to the present invention, each user can be by being positioned at the interface input channel credit rating of front end, or produce channel quality level in the initial moment that produces user record.These values are sent to CCU usually, at the CCU place, they are stored in the database, are used at described example distribution service channel.Certainly, those of ordinary skill in the art will recognize can provide channel quality level to the user by other device rather than by CCU.
No matter when CAU is registered to communication system 100, and channel quality level that can be from database retrieval to relevant user also is downloaded to CAU.Registration is that CAU allows communication system 100 understand these CAU to be in process in the system.Registration process relates to the information exchange between CAU and CCU, and this information comprises channel quality level.Comprise these values by the CAU in each channel request then.Each request from CAU comprises a channel quality level, and this grade has defined a high-quality value and a low-quality value.
Controller 114 among the CCU102 is carried out the Traffic Channel management.Controller 114 is preserved the tabulation of an operational Traffic Channel, and according to the QM-R of relevant channel Traffic Channel is associated with (channel quality) group (sets).Controller 114 uses a credit rating table to carry out the management of Traffic Channel.
Refer now to Fig. 6 B, this figure has described the TCH ordering chart in the credit rating table according to the present invention.With reference to credit rating table 602, according to the present invention, this credit rating table is used to carry out the Traffic Channel management.At each credit rating of being supported by communication system 100, credit rating table 602 comprises (accordingly) clauses and subclauses.As shown in Figure 6A, each credit rating table clause comprises a channel record inventory, and the QM-R value of these channel record is in the scope of definition channel quality level.In described example, credit rating table 602 comprises channel quality level 1-4.Credit rating table 602 comprises channel record tabulation 604-618.Each bar of these channel record comprises the current QM-R value of busy-idle condition of this channel and every channel.Each is new QM-R value of every channel calculation, and channel record will be reallocated to the different credit rating of possibility in the credit rating table.
With reference to Fig. 6 C, this figure describes according to the present invention and can how change channel record and distribute in response to receiving a new QM-R report.In response to receive all new values by CCU in QM-R report, in credit rating table 602, record 606,608 has been reallocated to different grades with 614.In Fig. 6 D,, a channel record figure has been described according to the present invention.Channel record 650 comprises a QM-R value in the clauses and subclauses 652.In clauses and subclauses 654, show effective bandwidth.Clauses and subclauses 656-670 comprises the clauses and subclauses of time slot 0-7, shows that a certain specific time slot is the free time or takies.Clauses and subclauses 656-670 can also show that whether the mass defect of corresponding time slot occurs.
When receiving a request to TCH, by the idle TCH on the channel satisfy with channel request in defined high-quality require corresponding.If this rank is empty, it is available perhaps not having idle TCH on other channel of this grade, so just seeks an idle TCH.This seeks the channel record tabulation of the continuous low-quality level of process check.When finding a channel, perhaps searched all quality when surpassing in channel request defined low channel quality requirement, search procedure stops.When only all grades between high and low channel quality requires are empty, require to compare with high-quality channel, the channel of " better " will be assigned with.If it is available not satisfying the TCH that lower quality of service requires, so because the unavailability of the resource of extra fine quality, this channel request will be rejected.When this situation occurs, be available if a low-quality channel is arranged, the user just has the selection than low-quality channel of employing so.In case selected a channel that distributes as TCH,, for example in the channel record 650 among Fig. 6 D, it is labeled as has taken in corresponding channel record.When before the channel of distribution when being released, be marked as the free time with the corresponding channel record of this channel.
Referring again to the credit rating table 602 among Fig. 6 C, when the channel request with high channel grade 3 and low channel grade 4 is received, because one is available, so the TCH of grade 3 is assigned with.Channel request with high channel grade 1 and low channel grade 2 causes TCH1 to be assigned with.Receive a request, will normally cause the TCH of grade 2 to be assigned with, if one is available with high channel grade 2 and low channel grade 2.In described example, it is available not having channel.So, according to best flow process, from the higher available grades of the next one, promptly the channel of grade 1 is assigned with.Channel request with high channel grade 2 and low channel grade 3 causes the TCH of grade 3 to be assigned with.Can find more detailed description below to all processes of managing all TCH.
The process of management service channel
Be according to the present invention below,, adopt quality metrics as described below, to the description of all processes of management service channel by the initialization of all ALT and all channel allocation.At first with reference to Fig. 7, this figure is used for the high level flow chart of process of all TCH in the supervisory communications (for example communication system among Fig. 1 100) according to the invention describes.This flow chart description the process followed of the processor in the controller 114 among Fig. 1.Controller 114 waits and processing are from various report and the request of all CPX.Quality metrics ordering (QM-R) value is used to all channels are sorted.QM-R is based on ARPL quality, all SNR values and WEI's.In CCU, periodically calculate the QM-R value by a line is busy CPX (CPX who has at least the line is busy TCH) for down link and uplink channel.Next, when a channel is assigned to this CPX, old QM-R will be provided for CPX.All quality metrics defectives (QM-Ds) are used to trigger one owing to disturb the ALT that causes.Utilization appears at word error in the transfer of data in times selected in the cycle, measure all ARPL level, or determines all SNR level, detects all QM-D.All CPX112 receive the various uplink data transmission that comprise all TCH requests, and these data are sent to controller 114, for processing, as shown in Figure 1.All CPX112 also produce the quality metrics report, and these reports are sent to controller 114.
This process starts from waiting for the input (step 700) that comes from a CPX (for example CPX112 among Fig. 1).The firm quality-ordered that receives is measured (QM-R) report, and just these channel rearrangements (step 702), after this process stops.Receive the TCH request from CPX-, just select a TCH, and carry out channel allocation, after this process stops.Trigger report in response to receiving a quality metrics defective (QM-D) from a CPX, select new TCH, and finish ALT (step 706), after this process stops.
Referring now to Fig. 8, this figure is a state diagram of describing CPX according to the present invention.At idle condition A1, CPX scans all frequencies and collects all QM-R values in the coverage.At engaged condition A2, CPX collects all QM-R values on allocated channel, and detects and report when QM-D triggers an ALT.When CCU distributes to the channel relevant with specific CPX to a TCH, CPX will be transformed into engaged condition A2 from idle condition A1.If the all-calls on the CPX finishes, and CPX do not comprise any system channel, and CPX will be from the not busy state A1 of engaged condition A2 transition back so.Have all system channels, all CPX of for example all SBC and all SAC are in idle condition A1 never.
Referring now to Fig. 9, this figure is a flow chart of describing idle CPX processing according to the present invention.Idle CPX processing is used to determine all relative power level decay (all ARPL), and these decay are utilized for the TCH distribution and all candidate's channels are sorted.CPX reads the list of frequency (step 900) of all RF channels in the coverage.Select first frequency (step 902) in this tabulation.After this, CPX is tuned to this table and goes up selected frequency (step 904).For being tuned to the channel calculation ARPL (step 906) of institute's selected frequency by CPX.Be this channel storage ARPL value (step 908), make then about whether this frequency is the judgement (step 910) of last frequency on the table.If this frequency is not last frequency, the next frequency (step 912) in this process option table so, and return step 904.
Otherwise, according to all ARPL values (all QM-R values in for example described example) all channels that sorts, here, the second-rate channel of 0 expression, and the channel (step 914) of higher value representation high-quality.Subsequently, the channel list after the ordering is sent to CCU (step 916), and after this this process stops.Next change Figure 10 over to, this figure is a flow chart that graphic extension the line is busy CPX handles according to the present invention.Adopting the line is busy, CPX handles to determine the appearance of word error on the uplink channel, SNR and ARPL value, and the appearance of word error on the downlink channel.Whether these values are used to determine that an ALT should occur and for distributing all TCH all channels that sorts.This process starts from being begun frame is deciphered by CCU, starts from time slot 0 (step 1000).Make the relevant judgement (step 1002) whether this time slot is being used.If this time slot is not in use, ARPL value of this process record is used for determining all SNR values (step 1004) so.
After this, this process increases progressively 1 (step 1006) to time slot.Make relevant whether this time slot and be the judgement (step 1008) of last time slot.If the time slot after increasing progressively is not last time slot, this process is returned step 1002 so, as described above.The last time slot of firm arrival, this process just checks whether QM-D has triggered an indication to understand, and shows for up link (UL) channel, needs an ALT (step 1010).In described example, for a uplink channel, when two continuous QM-D are detected, or 4 QM-D are when appearing in the times selected cycle, and QM-D triggers an indication, shows ALT of uplink channel needs.If be judged to be not, this process check so, whether QM-D has triggered an indication to understand, and shows down link (DL) channel ALT of needs (step 1012).For this down link (DL) channel, when two continuous QM-D occurred, perhaps when 4 QM-D in the frame appeared in the selected time cycle, QM-D triggered an indication, shows ALT of downlink channel needs.When showing that indication that an ALT is required is triggered by a QM-D, a QM-D triggers report and is sent to CCU, shows and implement ALT.Referring again to step 1010, if QM-D is for uplink channel has triggered an ALT, this process is just sent a UL QM-D to CCU and is triggered report (step 1014) so, and this process enters step 1012 then, as previously mentioned.
After turning back to step 1012, if QM-D has triggered an indication, show ALT of DL channel needs, this process sends a DL QM-D to CCU and triggers report in step 1016 so, revises QM-R value (step 1018) then.If QM-D triggers an indication, show the situation that needing not to occur ALT as yet, this process directly enters step 1018 from step 1012 so.From step 1018, this process has determined whether when CCU sends the QM-R value (step 1020).If be not at present that this process turns back to step 1000 so when CCU sends QM-R, otherwise before returning step 1000, this process sends QM-R report (step 1022) to the CCU of UL and DL channel.
Referring again to step 1002, if this time slot just in use, this process determines whether that word error indicating device (WEI) has been set (step 1024) in uplink frame so.If WEI is set, this process is labeled as defective (step 1026) to a last descending chain circuit frame so.
After this, a CRC mistake whether in uplink frame, occurred and judged (step 1028) at relevant.If WEI is not set in uplink frame, this process directly enters step 1028 from step 1024 so.Do not appear at as yet in the up link in case judged the CRC mistake, this process just determines whether that ARPL has exceeded scope (step 1030).If ARPL does not go beyond the scope as yet, whether the SNR value has exceeded scope judges (step 1032) at relevant so.As mentioned above, if the SNR value does not go beyond the scope, this process enters step 1006 so.
If the SNR value has exceeded scope, uplink frame is labeled defective (step 1034) so.If a CRC mistake appears in the up link, this process also directly enters step 1034 from step 1028 so.In addition, in step 1030, if ARPL has exceeded scope, this process enters step 1034 so, and is this frame flag defective.In described example, when single time slot comprised a WEI, it is defective that frame is marked as, and above-mentioned WEI is issued, and in the expression time slot mistake arranged.After having time slot more than 2 or 2 to be represented as defectiveness in a frame, such frame also can be labeled defective.According to most preferred embodiment of the present invention, when a channel had effective time slot more than 2 or 2, this type occurred.
Adopt all candidate's channels that sorted to distribute all Traffic Channels by quality in each channel and effective bandwidth.The ordering of all candidate's quality of channel can be based on the ARPL value, and resemble described in top Fig. 9 sort.Further, except the ARPL value, other combination of other value or these values can be used to sorted channels.For example, number and the SNR value that appears at the word error in a time cycle also can be used to the sorted channels quality.
Referring now to Figure 11, this figure is a flow chart of describing traffic channel assignment procedure will according to the present invention.This flowcharting receive a channel request and during the channel selecting to be used to distribute, finish this process as CCU by CCU.This process depends on that the channel grade that CAU stipulated is predetermined.As noted earlier, channel quality level has defined the desired channel quality of CAU.For example, some business, for example visual telephone more is sensitive to channel quality than other business (for example speech), therefore just requires higher-quality channel.
Channel quality level comprises a high-quality value and a low-quality value.High-quality value is that the user wishes to receive.The representative of this value has realized the channel quality of performance optimization, as the user awared of this channel.But, use the channel higher will can not make the user of this channel feel better channel quality than this channel quality.The minimum channel quality that low-quality value representative of consumer will be accepted.The channel that use is lower than by the quality of this value representative will cause the channel quality degradation, and as the user felt, this situation was unacceptable.The channel that use is in the quality between these two values causes the interior quality of normal tolerance interval, and is such just as what the user awared.For example, speech quality may not be " high-fidelity ", but is more or less the same with the common speech quality that provides of telephone system, and can be complementary with customer satisfaction system quality.
All credit ratings that common type of service of planning to provide according to them by service supplier comes define system to support.Then, the user will be allowed to select credit rating according to the type of service that it is receiving, and what the channel quality that does not need to understand bottom is.For example, the user may simply be video telephone or a credit rating is selected in voice call, rather than (abstractively) selects a usefulness 10 -6The credit rating represented of the error rate (BER).
This process starts from CCU and receives a TCH request, and channel quality level has been stipulated in this TCH request, the acceptability and the bandwidth requirement (step 1100) of the channel of demoting.Bandwidth requirement shows what tdma slots a user (in the quality of being asked) needs simultaneously for the communication type of desiring to ask (for example, video telephone is compared with the phone that only transmits sound needs more time slot).From the credit rating table, obtain high-quality value and low-quality value (step 1102).This credit rating table is the table of a high-quality value of regulation and low-quality value, for example table 600 among Fig. 6 A.On the other hand, high-quality value and low-quality value can be sent directly to CCU.Then, whether all channels are present on the high-quality inventory that enough bandwidth are arranged with regulation judges (step 1104) for relevant.If there is a good quality channel with enough bandwidth that satisfies regulation, this process is masked as the predetermined bandwidth amount of bandwidth that the line is busy on selected channel so, and gives CAU (step 1106) this allocated bandwidth, and this process stops subsequently.
Referring again to step 1104, if a certain channel is not present on the high-quality inventory that enough bandwidth are arranged with regulation, whether to the channel on this inventory has enough bandwidth and one and is in the height of credit rating and the value between the low-quality value so, makes one and judges (step 1108).If in by high and the defined scope of low-quality value, find 2 or a plurality of channel, so just select higher-quality channel.If this judgement is sure, so as mentioned above, this process enters step 1106.Referring again to step 1108, if there is no channel with enough bandwidth and quality, this quality is in by in the height of credit rating and the defined scope of low value, so just at whether one to have the channel that enough effective bandwidth and its quality be higher than the high-quality value of credit rating be available decision making (step 1110).If a higher-quality channel is available, this process proceeds to and gives CAU allocated bandwidth so, as top described in the step 1106.Otherwise the channel of this process degradation at whether is acceptablely to make one and judge (step 1112).
When the channel quality selection algorithm can not find one resemble at least low-quality value defined during the channel of high quality, some users may not accept a channel that does not satisfy the minimum quality of defined at least, the channel that other user of while may accept to demote, rather than can not get service at all.Except credit rating, the channel request regulation whether channel of a degradation will be acceptable.If the channel of degradation is acceptable, this process determines whether that the channel of demoting appears on the channel list with enough bandwidth (step 1114) so.If the channel of this degradation occurs, this process proceeds to and gives CAU allocated bandwidth so, as step 1106 is described.Otherwise CCU refuses this request (step 1116), and after this this process stops.Referring again to step 1112, if the channel of a degradation is unacceptable, this process also proceeds to step 1116 so, refuses this request.
According to the present invention, there is the mutation of several allocated channel methods that can adopt.The user preferably selects a channel quality level according to current calling.Determine channel quality level according to the interface that produces this connection.This interface is an equipment that links to each other with CAU.For example, interface can be a phone or a video conference system.Each user sends a calling, and this user determines that what quality it requires and comprise what information in call request.Desired quality will change along with the difference of calling out, and type of the business that is providing is provided for this.For example, CAU will have one with family in phone standard telephone interface and with all stand-alone interfaces of all isdn lines or video telephone.
On the other hand, the user of channel quality level selection is static.The user just informs the channel quality level of oneself when registration.This is that this user is with the grade of using.For the CAU of supporting telephone business only, this CAU can be used to provide the multiple combination of telephone service, facsimile service or all types of service of each standard.For the family's commercial affairs with two telephone lines, a circuit is special fax line, and another circuit is the telephone wire of standard, and every circuit should be assigned with identical credit rating.
Referring now to Figure 12, this figure is a flow chart that is described as the process of a channel of CAU distribution according to the present invention.This process starts from the TCH (step 1200) that selects one to be used to distribute.Subsequently, this process sends a message to CAU, tells the TCH (step 1202) that it is being assigned with, and adopts time gas exchange (TSI) that selected channel is connected to suitable network slot (step 1204), and after this this process stops.
Please see Figure 13, this figure is the flow chart describing the CAU request according to the present invention and be assigned with a process that TCH followed.This process starts from CAU and receives one group of credit rating (step 1300) from CCU.This process detects an interface (step 1302) that needs data transmission channel then.Then, CAU is the interface of a channel as requested, selects a channel quality level (step 1304) from this group channel quality level.For example, telephony interface, isdn interface or visible telephone interface produce this input that triggers this request.Then, a TCH request is formally proposed, and is sent to CCU (step 1306).After this, this CAU waits for the response (step 1308) among the CCU.
Just receive a response, just judge (step 1310) at whether a TCH has been assigned with from CCU.If this request is rejected, this process has judged whether to send a new channel request (step 1312) so.If do not send a new channel request as yet, this process is returned step 1312 so.Otherwise this process is returned step 1302.Referring again to step 1310, just receive TCH and distribute, this CAU just is tuned to the frequency of distribution and begins its communication or data transmission (step 1314), this process enters step 1312 to determine whether to send a request to additional channel, as described above simultaneously.
These schematic diagrames in Fig. 5-Figure 13 or all processes described in the flow chart can be implemented in the hardware shown in Fig. 2 C at Fig. 1 by those of ordinary skill in the art.Also can implement all processes of the present invention in a memory device, this memory device can be read by all processors in the above-mentioned hardware, and wherein, this memory device is encoded to the executable instruction in all processes of the present invention.Program storage device can be taked various forms, comprises such as (but being not limited to) hard disk drive, CD, ROM and EPROM or RAM, and these equipment are that those skilled in the art institute is well-known.
The all processes that are stored in the memory device are dormancy, have one up to employing and come effectively them as the memory device of the processor of microprocessor or DSP.For example, all processes of all channels of management can be encoded as the instruction that is stored in hard disk drive or the CD in communication system.Hard disk drive and CD are connected to processor among the CCU allows this processor to carry out all channels in these instructions and the supervisory communications.
Like this, the present invention has proposed a kind of improved communication system by proposing a kind of method, and this method relies in up link and the downlink channel collects quality metrics and come all ALT of initialization and distribute all channels.The present invention proposes a kind of improved method and apparatus, be used for by the data collection of relevant word error, SNR and all ARPL is determined that as being used for the quality metrics of all ALT comes all ALT of initialization.In addition, collected quality metrics is used to determine the channel quality of all channels, and these channels are used for each CAU allocated channel to a TCH of request in turn.The present invention proposes and be better than other method part, the channel that is used for being assigned with at those scope that is used for satisfying all channels carries out channel allocation, above-mentioned range of channels is defined by the poorest and optimal channel quality relevant with channel quality level, and be used for when not having other acceptable channel, only distribute to have than the higher-quality all channels of the channel of being asked.
Representing distinguishingly with reference to most preferred embodiment and describing the while of the present invention that those skilled in the art should understand: under the prerequisite that does not deviate from the spirit and scope of the invention, this paper can make on the various forms and content on variation.

Claims (10)

  1. One kind in communication system the management all channels method, in this communication system, all communication units interconnect by a cable distribution network, wherein, adopt a plurality of channels between all communication units of cable distribution network, to send signal, each of a plurality of channels is assigned with the part of one section frequency spectrum, and this method comprises:
    Between first communication unit and second communication unit, send transfer of data via first channel in a plurality of channels, wherein, from the transfer of data of second communication unit to the first communication unit is uplink data transmission, and the transfer of data from first communication unit to the second communication unit is a downlink transmission.
    Measure the quality metrics of active channel, this quality metrics comprises the quality metrics of down link of active channel and the quality metrics of up link;
    Measure the quality metrics of an idle channel in a plurality of channels;
    Adopt the quality metrics that has recorded, identification is also calculated the number that occurs mass defect in active channel and idle channel; And
    In response to discerning and calculating the number that mass defect occurs, manage the transmission of transfer of data between first communication unit and second communication unit.
  2. 2. cable communication system that has channel quality management, this communication system comprises:
    Cable distribution network;
    The basic communication unit that links to each other with this cable distribution network;
    The a plurality of communication units that link to each other with this cable distribution network;
    In a plurality of channels in this cable distribution network, adopt a plurality of channels to send signal between basic communication unit and a plurality of communication unit, each in a plurality of channels is assigned to the part of one section frequency spectrum; And
    Be the basic communication unit of a plurality of channel measurement quality metrics, all quality metrics comprise measuring at the downlink quality of active channel to be measured with uplink quality and measures at the uplink quality of idle channel; This basic communication cell response is discerned the appearance of mass defect in measuring all quality metrics on active channel and idle channel, and in response to the appearance of discerning mass defect, the communication in the management cable communication system.
  3. 3. communication system that has channel quality management, this system comprises:
    A cable distribution network;
    The basic communication unit that links to each other with this cable distribution network;
    The a plurality of communication units that link to each other with this cable distribution network;
    In a plurality of channels in this cable distribution network, adopt a plurality of channels to send signal between all communication units, each in a plurality of channels is assigned to the part of one section frequency spectrum;
    First decision maker is used for determining that all quality metrics of active channel, these quality metrics comprise that the downlink quality of active channel is measured with uplink quality and measure;
    Second decision maker is used for determining the quality metrics of the idle channel in a plurality of channels by measuring the power level of idle channel;
    Recognition device is used in response to definite quality metrics, the appearance of mass defect in identification active channel and the idle channel; And
    Management devices is used for the appearance in response to identification mass defect, the transfer of data in the management cable communication system.
  4. 4. communication unit in having the cable communication of channel quality management (system), said system comprises:
    One is applicable to the interface that is connected with cable distribution network, wherein, a plurality of channels are positioned at cable distribution network, this cable distribution network has as the first of a plurality of channels of active channel and as the second portion of a plurality of channels of idle channel, and each of a plurality of channels is assigned to the part of one section frequency spectrum; And
    Processing unit with a lot of mode of operations comprises:
    First mode of operation, in this mode of operation, processing unit is a plurality of channel measurement quality metrics, wherein, these quality metrics comprise that all downlink quality of a plurality of channels are measured with uplink quality and measure;
    Second mode of operation, in this mode of operation, processing unit is discerned the appearance of mass defect in a plurality of channels in response to measuring quality metrics; And
    The 3rd mode of operation, in this mode of operation, processing unit adopts the appearance of quality metrics that has recorded and the mass defect of having discerned, manages the transfer of data in a plurality of channels.
  5. 5. cable communication system that has channel quality management, this system comprises:
    A cable distribution network that comprises a plurality of channels, each channel in a plurality of channels is assigned to the part of one section frequency spectrum, wherein, adopts a plurality of channels to send transfer of data in cable distribution network;
    The a plurality of cable access units that link to each other with cable distribution network;
    A cable communication unit that links to each other with cable distribution network, this cable communication unit comprises:
    A controller; And
    A plurality of transceiver units, wherein, each transceiver unit in a plurality of transceiver units is operated in idle condition and engaged condition,
    Wherein, an interior transceiver unit measurement of a plurality of transceiver units that is in idle condition decays with respect to the relative power level on the idle uplink channel in a plurality of channels; The transceiver unit that is in engaged condition in a plurality of transceiver units is measured word error and the signal to noise ratio in the uplink channel that the line is busy; And the transceiver unit in the engaged condition of being in a plurality of transceiver units is measured one the line is busy word error in the downlink channel, wherein, all measurements of having done by a plurality of transceiver units have been adopted in the process of the transfer of data in the control cable distributed network.
  6. 6. a kind of cable communication unit in having the cable communication system of channel quality management, this cable communication unit comprises:
    One is suitable for the interface that is connected with cable distribution network;
    The a plurality of transceiver units that link to each other with this interface; And
    A controller that links to each other with a plurality of transceiver units,
    Wherein, idle transceiver unit in a plurality of transceiver units is measured the relative power level decay on the idle uplink channel, word error on word error and signal to noise ratio on the line is busy in a plurality of transceiver units transceiver unit measures the line is busy the uplink channel and the line is busy the downlink channel, wherein, in the process of the transfer of data in the control cable distributed network, adopted by idle transceiver unit and the line is busy measurement that transceiver unit done.
  7. 7. memory device, this memory device can be read by the processor in the communication unit, and the processor executable that is used to manage the Traffic Channel in having the cable communication system of channel quality management is encoded, and this memory device comprises:
    First instruction of the quality metrics of the up link of measuring that the line is busy and the line is busy downlink channel;
    Measure second instruction of the quality metrics of idle uplink channel; And
    In response to measuring quality metrics, the 3rd of the transfer of data in the control cable communication system is instructed, and wherein, when this memory device was connected with a processor, first, second and the 3rd instruction were effective.
  8. 8. the subscriber communication units in a communication system that has a channel quality management, this subscriber communication units comprises:
    One is applicable to the interface that links to each other with cable distribution network in the communication system; And
    A processor that is connected to this interface, in this interface, processor has a lot of mode of operations, comprising:
    First mode of operation, in this mode of operation, processor is discerned the scope of all channel qualities according to the type of the transfer of data of being carried out between subscriber communication units and communication system;
    Second mode of operation, in this mode of operation, processor sends a channel request to communication system, and wherein, this request is included in the scope of all channel qualities of being discerned in first mode of operation; And
    The 3rd mode of operation, in this mode of operation, processor receives the request responding to sending in second mode of operation.
  9. 9. memory device, this memory device can be read by the processor in the communication unit in having the communication system of channel quality management, and this memory device is encoded to the executable instruction of processor, and this memory device comprises:
    First instruction is used for the type according to the transfer of data of being carried out between subscriber communication units and communication system, discern the scope of all channel qualities.
    Second batch of instruction is used for sending a channel request to communication system, and wherein, this request comprises the scope of all channel qualities of being discerned by first instruction; And
    The 3rd batch of instruction is used for receiving a request responding to sending second batch of instruction, and wherein, when memory device was connected to a processor, first, second and the 3rd batch of instruction were effective.
  10. 10. communication unit that in having the cable communication system of channel quality management, uses, this communication unit comprises:
    One is applicable to the interface that is connected with distributed network in the cable communication system, this interface provides a kind of connection, be used on distributed network, sending and receiving transfer of data, wherein, on a plurality of channels, launch transfer of data, each channel is assigned to the part of a radio spectrum, in this channel, this part radio spectrum by the time be divided into a plurality of time slots; And
    A receiver that links to each other with this interface, wherein, this receiver receives all modulated message signal from this interface, and all modulated message signal are converted to numerical data;
    A transmitter that links to each other with this interface, wherein, this transmitter is all modulated message signal of digital data conversion for transmitting on cable communication system;
    A processing unit that links to each other with transmitter and receiver;
    One is applicable to the local loop interface that is connected to subscriber equipment; And
    One and transmitter, PCM coder/translator unit that processing unit links to each other with the local loop interface, wherein, the numerical data that comprises user data is converted into the employed analog form of user, and wherein, analogue data from the user is converted into digital form, wherein, processor obtains one group of channel quality level from cable communication system, and according to the data transmission of between cable communication unit and cable communication system, being carried out, from this group channel quality level, select a channel quality level, send a channel request to cable communication system, wherein, this request comprises channel quality level, and receives a response from cable communication system.
CN 96192741 1996-01-22 1996-12-21 Channel quality management in a cable telephony system Pending CN1179252A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN 96192741 CN1179252A (en) 1996-01-22 1996-12-21 Channel quality management in a cable telephony system

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US08/589,842 1996-01-22
CN 96192741 CN1179252A (en) 1996-01-22 1996-12-21 Channel quality management in a cable telephony system

Publications (1)

Publication Number Publication Date
CN1179252A true CN1179252A (en) 1998-04-15

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002056601A1 (en) * 2001-01-10 2002-07-18 Huawei Technologies Co., Ltd. A method for processing error code of compressed image in transmission
CN103428865A (en) * 2013-06-24 2013-12-04 哈尔滨海能达科技有限公司 Wireless link distribution method and wireless link distribution system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002056601A1 (en) * 2001-01-10 2002-07-18 Huawei Technologies Co., Ltd. A method for processing error code of compressed image in transmission
US7051262B2 (en) 2001-01-10 2006-05-23 Huawei Technologies Co., Ltd. Method for processing error code of compressed image in transmission
CN103428865A (en) * 2013-06-24 2013-12-04 哈尔滨海能达科技有限公司 Wireless link distribution method and wireless link distribution system
CN103428865B (en) * 2013-06-24 2016-03-30 哈尔滨海能达科技有限公司 A kind of wireless link distribution method and system

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