CN1154190A - Non-transparent data transmission in a digital telecommunications system - Google Patents
Non-transparent data transmission in a digital telecommunications system Download PDFInfo
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Abstract
The invention relates to a digital telecommunications system, and particularly a method for non-transparent data tranmission. There is a non-transparent data connection (V.110+L2R/RLP) between a transmitting party (A) and a receiving party (B), on which channel coding is employed. The transmission buffer buffers the data frames to be transmitted and stores the transmitted data frames until it receives an acknowledgement of successful reception. In accordance with the invention, this is avoided by monitoring the quality of the non-transparent connection, and if the quality of the connection drops to a specific threshold value, by changing the channel coding scheme of the connection for a more efficient one. Simultaneously, however, more channel capacity is allocated for the connection in according with the chosen channel coding scheme so that the original nominal user data rate can be maintained unchanged or nearly unchanged.
Description
The field of the invention
The non-transparent data that the present invention relates to digital communication system and be particularly related in the radio interface of mobile communication system sends.
Background of the present invention
For disturbing responsive transmitting channel (for example radio route) to go up the problem that sends, commonly send of poor quality.Though all having error correction protocol-these agreements, the terminal of several standards-terminal data service is applicable to that whole terminal-terminal connects or some part of transmission path, these agreements all are that the typical error situation for fixed line designs, but they are for the radio link of specific situation-for example-be insufficient or unaccommodated.Therefore, need in mobile communication system, adopt special-purpose error correction solution.
Since do not have a solution can be applicable to all data, services, thereby some kinds of connections are arranged, for example connection in pan-European mobile communication system GSM, and these connections can be divided into two classes.In the first kind, error correction is only undertaken by chnnel coding, and this is called as forward error correction (FEC) in gsm system.In the GSM suggestion, this is called as transparent transfer mode, also is abbreviated as T.Connect in the kind at second kind, except chnnel coding, also adopted additional agreement, and obtained resending in the data that the other end is not correctly received.In gsm system, this communication protocol is called as radio link protocol (RLP), and this data transfer mode is called as nontransparent asynchronous data and sends, and also is abbreviated as NT.The present invention relates to non-transparent data sends.
In the nontransparent asynchronous data that connects through circuit switching sent, the data in rlp frame were sent to a recipient B from transmit leg A.This rlp frame is the process chnnel coding during sending, thereby the error that transmitting channel is caused can be proofreaied and correct by recipient B in channel-decoding.Except the user data of reality, rlp frame also comprises the error correction position, can detect the error of not proofreaied and correct by chnnel coding by its recipient B.Each rlp frame also obtains numbering, perhaps represents the order of frame with the another kind of mode of indicating.The correctness of each frame that receives obtains test at receiving terminal.If frame is detected as correct, then the recipient will utilize frame number to confirm to receive.If frame is not detected as correctly, then send the affirmation negating.When transmitting terminal received a Negative Acknowledgement or do not receive the confirmation, transmit leg A resend predetermined times with rlp frame.The total degree that resends is limited, to avoid producing endless transmission ring under the situation of the connection of non-constant.
Rlp frame is stored promptly that " buffering " is identified up to them at transmitting terminal, resends thereby they can be accessed when needed.In order to limit required buffering capacity, in the RLP agreement, adopted a sliding window.Therefore, transmit leg A can send several rlp frames before requiring from the affirmation of recipient B.Because the mistake that transmits by chnnel coding has obtained correction by resending defective rlp frame, resends reservation " unnecessary capacity " so be necessary for.This means the rating data speed height of the data rate of nontransparent connection than the user.Channel has under the situation of better quality therein, and promptly the mistake that can not proofread and correct when chnnel coding is seldom the time, and this unnecessary capacity allows resending of enough numbers and actual connection data rate is dropped under the specified user data rate.When the quality of connection variation, defectiveness and the rlp frame of losing, and the number that resends that therefore causes increases.Connecting under the extremely poor situation, must adopt rlp frame buffering and flow control, this has limited the data volume that enters transmission buffer from the user.This means that actual in practice user data rate is lower than specified user data rate, promptly the throughput of Lian Jieing has reduced.
Thereby with the relevant problem of transmitting channel of difference, be when resending number of times when increase, the throughput of connection drops under the specified user data rate.If the number of times that resends further increases, and in some frame, reached for connecting the maximum of setting and resend number of times, then caused resetting of RLP agreement, thereby make A and B side reset their and the relevant built-in variable of data transmission.Reset with RLP and to interrelate, can produce information dropout, and thereby can not guarantee the continuity of data.Reset under the state data at RLP and send and be practically impossible, because reset the release that causes connection.
The influence of transmitting channel of difference can be used better connecting channel encoding scheme instead and reduced, as long as there are some available chnnel codings in system.For example, the channel coding schemes FEC that is used at gsm system is a convolutional encoding, and its efficient can represent that this shows that X data bit represented with Y bits of coded in chnnel coding with rate convolutional encoder X/Y.For example in full rate gsm service channel, the rate convolutional encoder corresponding with user data rate 9.6kbit/s, 4.8kbit/s and 2.4kbit/s is 1/2 respectively (the 1/2nd, so-called buffering ratio, promptly this ratio is not accurately 1/2), 1/3 and 1/6.On half rate, be respectively 1/2 and 1/3 for the corresponding convolution coding ratio of the user data rate of 4.8kbit/s and 2.4kbit/s.Thereby adopt better and more effective channel coding schemes, need to reduce specified user data rate.
Of the present invention open
Purpose of the present invention is that the non-transparent data that improves under the poor transmit path condition sends throughput, and keeps rating data speed and/or connection under the condition of the non-transparent data transmission failure of prior art therein.
This is to realize by a kind of non-transparent data sending method in the digital communication system, this method may further comprise the steps: set up a non-transparent data and connect, it has a rating data speed, first a transmission capacity and one first channel coding schemes; Connect the transmission data by a non-transparent data in the Frame that utilizes a communication protocol, the correct data frame that this protocol validation receives also resends the defective Frame that is received; With the frame data buffer that will send in a transmission buffer; Under the situation that may resend, the Frame that sends is stored in the transmission buffer, up to receiving the affirmation that successfully receives.The invention is characterized in
According to the throughput that resends the connection of number of times monitoring non-transparent data,
If the throughput that data connect drops to one below the predetermined threshold, then is bigger transmission capacity of described data connection request and more efficiently channel coding schemes.
The invention further relates to a kind of communication system according to Claim 8.
In the present invention, the quality of nontransparent connection has obtained monitoring, and if the quality that connects drop to below the specified threshold value, then change more efficiently channel coding schemes for connecting.Yet, distribute bigger channel capacity for connecting simultaneously, so that original specified user data rate can remain unchanged or near constant according to selected channel coding schemes.For example half rate can be changed into a traffic channel full rate, and can adopt more efficiently channel coding schemes simultaneously.Correspondingly, can adopt therein in the system of multichannel connection, the number of channel can obtain increasing, thereby can adopt more efficiently channel coding schemes under the situation that does not reduce rating data speed.
In one embodiment of the invention, if there is not how obtainable channel capacity, then current channel coding schemes and channel capacity are maintained.If the latter linked quality in the predetermined stand-by period is still poor, then carry out one or more new trial to increase channel capacity and to change channel coding schemes.In one embodiment of the invention, though also there is not more channel capacity to obtain after new effort, if the throughput that connects still is lower than predetermined threshold value, channel coding schemes is changed into more efficiently a kind of.If the improvement of terms that connects can remove unnecessary channel capacity from connect, and original channel coding schemes can be restored.This channel capacity discharges the connection of having given other.
Brief description of the drawings
Below, will in conjunction with the accompanying drawings and by most preferred embodiment the present invention be described.In the accompanying drawings:
Fig. 1 has shown that wherein the present invention can be applied to the part of the mobile communication system of the nontransparent connection of single channel,
Fig. 2 is a block diagram, has shown the functional unit of the nontransparent gsm service channel of single channel in the different protocol layers,
Fig. 3 has shown a L2R PDU,
Fig. 4 is a rlp frame,
Fig. 5 has shown the part that wherein can be applied to the present invention the gsm mobile communication system of a nontransparent connection of multichannel.
Most preferred embodiment of the present invention
The non-transparent data that the present invention can be applied in all digital data communication systems connects, on this data connect, except chnnel coding, also send error correction, and this transmissions agreement resends frame and makes actual data rate drop to below the rating data speed or make the connection interruption when the degradation that connects by a kind of transmission agreement.
The present invention is specially adapted to the data transmission applications in digital CDMA or the TDMA mobile communication system, such as pan-European digital mobile communication system GSM, DCS1800 (digital communication system), according to the system of temporary transient standard I S/41.3 of EIA/TIA or the like.Below will describe the present invention, but the present invention is not limited only to this system by the example of gsm mobile communication system.The basic structure of gsm system will briefly be described below, but will not give too much attention to other aspects of its feature or this system.This gsm system is at M.Mouly, the title of M.Pautet be " gsm mobile communication system " article (Palaiseau, France, 1992, obtained detailed description in ISBN:2-9507190-0-7), this article is used as list of references at this.
The mobile MSC of switching center that serves switches the calling that enters and go out.It is carrying out and the similar task of PSTN (PSTN).In addition, the function that it is also being born mobile communication and is had especially is such as cooperate the customer location management of carrying out with the user register (not shown) of network.Travelling carriage (MS) links to each other with MSC through base station system BSS.Base station system BSS is made up of base station controller BSC and base station BTS.
Gsm system is a time division multiplex system, and wherein the communication on the radio route occurs in in succession the tdma frame, and each frame all is made up of some time slots.In each time slot, the packets of information of a weak point obtains sending with a kind of form of RF pulse string, and this RF pulse string has finite duration and be made up of one group of modulated position.Time slot mainly is used to transmit control channel and Traffic Channel.On Traffic Channel, voice or data obtain sending.On control channel, the signaling of carrying out between base station and the travelling carriage sends.The channel architecture that is used for the radio interface of gsm system has obtained more detailed regulation in GSM rule 05.02.In the operation according to this rule, time slot is assigned to mobile station MS with as Traffic Channel (single time-slotted access) when calling out beginning.Mobile station MS and this slot synchronizationization are to send and the received RF pulse train.
In gsm system, between the function that cooperatively interacts (IWF) 42 of the terminal adapting function (TAF) 31 and a fixed network (interrelating with MSC usually) of mobile station MS, set up data and be connected.It is that a kind of circuit switches connection that data connect, and it has kept (or a plurality of) Traffic Channel from radio interface during whole calling.In the data of GSM network sent, it was that V.110 rate adapted, V-24 interface can be adaptive, UDI coded digital full duplex connects that these data connect.V.110 connecting is a kind of digital transmitting channel, and it is originally for ISDN technology (integrated services digital network) exploitation, it be defined within CCITT rule blue book V.110 in.V.110 terminal adapting function TAF adapt to the data terminal TE that links to each other with mobile station MS to be connected, and this is connected among Fig. 1 is foundation on the circuit switching of adopting a Traffic Channel ch0 connects.V.110 the function that cooperatively interacts IWF makes the V.110 network (such as ISDN or other GSM networks) that connects with some other suitable, or with some other to transmit networks (such as PSTN) suitable.
In addition, on this Traffic Channel, adopted chnnel coding FEC (forward error correction), to reduce to send wrong influence to radio route.In gsm system, adopted convolutional encoding, and its efficient can represent that this ratio shows that X data bit represented by Y bits of coded in chnnel coding by the convolutional encoding ratio according to GSM rule 05.03.For example, on full rate gsm service channel, the rate convolutional encoder corresponding with user data rate 9.6kbit/s, 4.8kbit/s and 2.4kbit/s is respectively 1/2,1/3 and 1/6.
On the gsm service channel, terminal adapting function (TAF) is connected with nontransparent circuit switching between the function that cooperatively interacts (IWF) and comprises several protocol hierarchies.
The terminal adapting function TAF of mobile station MS and the terminal interface between the data terminal equipment, and cooperatively interact function IWF and for example interface between audio frequency modem meet CCITTV.24, and represent with symbol L2 in the drawings.Basic agreement of the present invention is L2R (layer 2 relay) and RLP (radio link protocol), and they all are located at the terminal adapting function TAF that connects the place, two ends and cooperatively interact between the function IWF.According to the present invention, this connection also comprises some rate adapted RA functions, such as terminal adapting function TAF and place RA1 ', the CCU unit between the CCU unit (channel encode-decode unit) of BSS and a code converter unit TRAU that RA1, CCU unit and the base station between the function IWF of cooperatively interacting is provided with separately between RAA and at this code converter unit TRAU and the RA2 between the function IWF of cooperatively interacting.Rate adaptation function RA has obtained definition in GSM specification 04.21 and 80.20.Communicating by letter between CCU unit and the transcoder unit TRAU obtains definition in GSM rule 08.60.
Obtain the information of rate adapted at radio interface RA1 ', also the mode with regulation in the GSM rule 5.03 obtains chnnel coding.This is represented by the module FEC in mobile station MS and the CCU unit.
Yet, purpose of the present invention, just terminal adapting function TAF operates and communicating by letter between them with the L2R/RLP of the adaption function IWF that cooperatively interacts.The lower layer protocol of above-mentioned other, function and unit only provide between the L2R/RLP transmission path according to the GSM rule, and they are irrelevant with the present invention except chnnel coding.Therefore, do not give further attention at this to them.
Be used for the L2R (layer 2 relay) of nontransparent character-oriented agreement, for example obtaining definition in the GSM rule 07.02.L2R is to being that user data and the state information that the protocol data unit PDU of 200 or 25 eight hytes receives divided into groups from terminal interface with length.In Fig. 3, shown a PDU.These eight hytes from 0 to 24 obtain numbering, thereby at first send eight hytes 0.Position from 1 to 8 in eight hytes obtains numbering, and at first sends position 1.Eight hytes in PDU can be eight hytes of state, a character (data of higher level) or illusory position.Eight hytes 0 are eight hytes of a state always.Eight hytes of a state comprise 3: the X of SA, SB and the state that V.24 is connected, and comprise 5 positions of the number that is used to represent eight hytes of data after eight hytes of this state, and special-purpose expression, such as the PDU of sky.In Fig. 3, be that eight hytes of 3 data-wherein word " GSM " is encapsulated in together after eight hytes of state 0, be eight hytes 4 of a new state after this.
L2R PDU is encapsulated as a frame according to the RLP agreement, as shown in Figure 4.The RLP agreement obtains definition in GSM rule 04.22.This RLP is that balance (HDLC type) data that have frame structure send agreement, and wherein error correction is based on and resends defective frame under recipient's request.RLP extends to from the terminal adapting function TAF of MS that the function IWF that cooperatively interacts-it is placed in the MSC usually.According to Fig. 4, this rlp frame structure comprises a header field (16), an information field (200) and a FCS (24).200 L2R PDU are packed to advance information field.Thereby the RLP data rate obviously is higher than a maximum user rate 9.6kbit/s that channel allowed only, and this makes it possible to carry out some resending under the situation that does not reduce specified user rate.When the user rate in the terminal interface is 9600kbit/s, and the data rate in radio interface is 12kbit/s, and this " unnecessary capacity " is about 12.5%.
The RLP agreement also links to each other with flow controller, and this controller is used to control the fill level of reception and transmission buffer.This flow controller is for example obtaining description in the GSM rule 07.02.If if see that from the direction of radio route reception buffer has reached the local flow control that predetermined threshold value or terminal equipment TE have started terminal interface, then the L2R/RLP of recipient B sends one " flow controller activations " indication immediately to transmit leg A.Under latter event, when receiving from the flow control of terminal interface indication, the data that L2R/RLP interrupts from reception buffer to terminal interface send.When having eliminated the obstruction of buffer or local flow controller, L2R/RLP sends one " flow control un-activation " indication.In addition, restarted from the data transmission of reception buffer.When transmission buffer reaches a predetermined threshold or when L2R/RLP received from recipient B " flow control activation " indication, the L2R/RLP unit of transmit leg A activated the local flow controller immediately.When having eliminated the obstruction of buffer, perhaps when receiving " flow control un-activation " indication, L2R/RLP will cancel local flow control.The data that transmission buffer buffering receives from interface V.24, thus can not be immediately data can not lost sending under the data conditions on the radio route at mobile station MS.Reception buffer cushions data.Thereby can not be through this interface and be unlikely obliterated data under the situation of terminal equipment TE for example V.24 in data.The described predetermined threshold that activates flow control can be for example to send or reception buffer half-full.
As mentioned above, the RLP agreement has a problem, and promptly when the degradation that connects, the number of the number of defective and the frame of losing increases, thereby causes resending number of times and increase.Connecting under the extremely poor situation, can adopt rlp frame buffering and above-mentioned flow control.In practice, this means that actual use speed is lower than specified user data rate, promptly the throughput of Lian Jieing has reduced.
According to a most preferred embodiment of the present invention, carried out making great efforts addressing this problem, thereby made the throughput of L2R/RLP unit by reducing to connect of transmit leg, and, monitored the quality of connection preferably also by the fill level of monitoring transmission buffer.Rlp frame resend number of times also unrestricted-this is different with RLP agreement according to the GSM rule, thereby answering of having avoided that RLP connects put.As mentioned above, in the current GSM system, when having reached maximum, the number of times that resends takes place to put again.
Below by example an embodiment is described, wherein by transmit leg monitor connection quality, change channel coding schemes and the outer capacity of amount of the claim.But these processes can be replaced carrying out according to identical principle by receiving terminal.In the case, or transmission buffer do not monitored, or the fill level of transmission buffer is indicated from " flow control activations " that obtained by transmitting terminal and obtained.
Dropped to predetermined value if the fill level of transmission buffer has reached predetermined value and throughput, the channel coding schemes FEC of connection is changed and is more efficiently one, and asks more channel capacity.Because also need being lower than channel coding schemes by the residual error rate that the RLP agreement is proofreaied and correct, better channel coding schemes FEC, remnants change before.Because radio channel capacity may obtain increasing satisfying the needs of new channel coding schemes, thereby rating data speed can remain unchanged or almost constant.
If there is not obtainable extra channel capacity, L2R/RLP continues to send with current transmission configuration.The L2R/RLP unit comprises one and reattempts timer, and it is activated at this moment.If quality of connection is still bad after timer expiration, then carry out new trial, and under the situation of this new trial failure, timer is activated or the like again for increasing channel capacity.If the throughput that connects further is reduced to a lower predetermined value, then be changed to more efficiently one, to improve error correction at the channel coding schemes in any case that does not have the extra channel capacity in this process.Thereby can keep connecting, even at lower user rate.A reasonably lower predetermined value of throughput is certain value that is lower than the higher nominal data rate of next channel coding schemes FEC.
If radio condition is improved again, then can send extra channel resource back to, and channel coding schemes can be changed get back to original.The decision that turns back to original configuration can be made according to predetermined throughput value.
Channel coding schemes is undertaken by a channelling mode correction (CMM) program, and this program has obtained description in for example GSM rule 04.08 among pp.53-54 and the 181-182.Channel allocation and CMM program have all obtained the particularly control of its calling controling CC (42) of MSC in most preferred embodiment of the present invention.
1.0 the judgement standard of request channel resource
When the fill level of monitoring transmission buffer, the activation threshold of above-mentioned flow control is used to activate solicited status.In the case, adopted hysteresis in case solicited status is cancelled in the control of fluid stopping amount, in case promptly solicited status has obtained activating, it only just can be cancelled after the fill level of buffer has been reduced to lower threshold value.
Monitoring to throughput is according to the calculating that resends speed of frame is carried out.Because transmission buffer is half-full, RLP continues at full speed that rate sends.This speed knows that according to channel capacity for example under the situation of full rate gsm service channel, this speed is a frame/20 millisecond (50 frame/seconds).If for example 55% of the frame that sent last time resend, then 45% capacity will be used to new frame.
The monitoring throughput can also be based on the calculating to ratio in succession " slide or float ", for example by following formula:
AVE (n+1)=AVE (n) (1-D)+MEASD wherein AVE (i) be the mean value of i constantly,
D is " historical coefficient " (0＜D＜1)
MEAS is last time " measurement "
MEAS=1 represents successfully to confirm to send
MEAS=0 represents resending of frame
O≤AVE(i)≤1。
2.0 discharge the judgement standard of channel resource
When user data had sent that rate and average success rate AVE (i) have been carried out at full speed, extra channel resource obtained discharging, wherein average success rate AVE (i) in preset time (such as 10 seconds or 100 seconds) lining greater than predetermined value (for example 0.8).Even this standard has temporarily stopped sending the channel resource that also keeps additional allocation under the data conditions at terminal equipment.Therefore avoided discharging between channel resource and the request channel resource repeatedly, and channel resource only just obtains release after the actual improvement of radio condition.
The present invention can be applied to single channel service and multichannel high speed circuit switched data service (HSCSD).To two kinds of situations be described by example below.
3.0 based on half-rate channel and the application x in single channel service
In gsm system, can under the situation of low rate, select so-called half rate (maximum 4.8kbit/s) Traffic Channel (HR).When mobile station MS only when in certain time slot of a frame, moving, when promptly moving with half rate, half rate has obtained foundation.Another kind of travelling carriage is arranged, and it moves in a frame identical time slot.
If having nontransparent circuit switching on a half rate gsm service channel, mobile station MS connects.Send and will be described under following supposition according to data of the present invention, promptly terminal adapting function TAF is that the transmit leg A and the function IWF that cooperatively interacts are recipient B.But it should be noted that data are sent in the opposite direction of IWF-TAF and take place in an identical manner.
The fill level and the throughput that is connected of the L2R/RLP unit continuous monitoring transmission buffer of transmit leg A.When degradation that connects and error number increase, following incident takes place:
1) number that resends of rlp frame increases,
2) fill level of transmission buffer reaches the flow control activation level, thereby makes flow control obtain activating,
3) number of times that resends of single frame reaches a predetermined maximum value, but this is not considered according to the present invention,
4) throughput of Lian Jieing drops to a decision value, and it is a value between half of original specified user rate and original specified user rate.
When condition 2 and 4 was all set up, channel coding schemes was asked to change in the L2R/RLP unit of transmit leg A by a CMM program, and Traffic Channel is changed to a traffic channel full rate, to keep original rating data speed.After CMM program and traffic channel full rate were allocated successfully, data sent with original data rate and continue, but used channel coding schemes FEC is better.
When channel coding schemes had changed over more efficiently one, the throughput that the L2R/RLP unit continuous monitoring of transmit leg A connects was to return original channel coding schemes and channel resource when radio condition changes.
Example 1. communication occurs on the half rate gsm service channel-and original thereon user rate is that 4.8kbit/s and radio interface speed are 6kbit/s.When the throughput that connects drops to decision value (for example 4kbit/s) when following, the fill level of transmission buffer reaches the flow control activation level, and flow control obtains activation.The L2R/RLP unit asks the CMM program all to have the user rate of 4.8kbit/s and the traffic channel full rate of radio interface speed to change subsequently.Data send thereby obtain continuing under original user rate, but carry out with more efficiently channel coding schemes FEC because the convolutional encoding ratio of full speed channel is 1/3 and user rate is 4.8kbit/s, half-rate channel then be 1/2.
If the full speed channel that can not obtain to ask, data are sent on the existing half rate and proceed.L2R/RLP activates and reattempts timer.If present condition remains establishment after timer expiration, then carry out new trial with the increase channel capacity, and if new trial failure, timer is activated again or the like.If the throughput that connects is still reduced to the minimum predetermined value of determining, the channel coding schemes of half rate is changed by the CMM program and is more efficiently scheme.A reasonable value of described low predetermined decision value is lower than half of original specified user rate.
Example 2. data occur on the half rate-and original user rate is 4.8kbit/s on this channel, and the radio interface data rate is 6kbit/s and FEC=1/2.When the quality of connection variation, throughput drops to below the 2.4kbit/s, and the fill level of transmission buffer reaches the flow control activation level, and flow control obtains activating.Simultaneously, the resending number and may reach predetermined maximum value of single frame, but this is not considered according to the present invention.CMM program of L2R/RLP unit requests is with the configuration of the radio interface speed that Traffic Channel changed over user rate with 2.4kbit/s and 3.6kbit/s.Subsequently, data send carries out on half rate with the lower rating data speed of 2.4kbit/s, but corresponding to more efficiently channel coding schemes FEC=1/3.
4.0 be applied to single channel service based on full speed channel
Suppose that the ongoing nontransparent circuit switched data that mobile station MS has on traffic channel full rate connects.The fill level of the L2R/RLP unit continuous monitoring transmission buffer of transmit leg A, and the throughput that connects.When the degradation that connects and error number reduced, following incident took place:
1) number of times that resends of rlp frame increases,
2) fill level of transmission buffer reaches the flow control activation level, and flow control obtains activating,
3) number of times that resends of single frame reaches a predetermined maximum, but this is not considered according to the present invention,
4) throughput of Lian Jieing is reduced to a decision value, and this decision value is lower than half of original specified user rate.
When condition 2 and 4 was all set up, the L2R/RLP unit of transmit leg A changed channel coding schemes by a CMM PROGRAMMED REQUESTS.After the CMM of success program, data send and continue on same single Traffic Channel with lower rating data speed (originally half), but channel coding schemes FEC is better.
After changing to more efficiently channel coding schemes, the L2R/RLP unit continues monitoring:
The fill level of-transmission buffer and the throughput of connection, detecting changing to the possible needs of better channel coding schemes,
The throughput of-connection is to return transmission rate faster when radio condition changes.
These can use-case 3 explanations.The original user rate of full speed channel is 9.6kbit/s, and radio interface speed is 12kbit/s, and FEC=1/2.The throughput that connects is reduced to 4.8kbit/s fill level following and transmission buffer and is reached the flow control activation level, and flow control obtains activating.So CMM program of L2R/RLP unit requests, this program changes to user rate 4.8kbit/s and radio interface speed is changed to 12kbit/s.Subsequently, data are sent under the lower specified user rate and proceed, but good channel encoding scheme FEC=1/3 is arranged.
5.0 being applied to multichannel high-speed data sends
The highest permission user data rate on a gsm service channel is limited in 9.6kbit/s.
Inventor application FI-942190 and FI-945817 in the past announced a kind of program, wherein carries out the mobile station MS of data transmission for two or more time slot allocation with the speed that is higher than the transfer rate that institute can provide on a Traffic Channel request from same tdma frame.Maximum user rate on multichannel data connects is: the user rate 9.6kbit/s of the number of concurrent service channel * one Traffic Channel.Therefore, for example the user rate of 19.2kbit/s can provide with at least two Traffic Channels.The conduct in this application of this program is carried out announcing based on an example of the high-speed data transmission of a plurality of concurrent service channels in radio system.As for the details of this process, see also above-mentioned application.But it should be noted that the thing relevant with the present invention just set up multichannel and sent the possibility that connects, thereby purpose of the present invention mainly is the efficient that changes channel capacity and channel coding schemes when the mass change that connects.
Fig. 5 has shown the structure of the GSM network of implementing a plurality of concurrent service channels transmission of this employing data.Fig. 5 and Fig. 1 are similar, just have nontransparent connection of circuit switching-this connection to be made up of N concurrent service channel ch0-chn at terminal adapting function TAF between the function IWF with cooperatively interacting in Fig. 5, n=1 wherein, and 2,3 ...In travelling carriage, TAF plays a part distributor, will be assigned to concurrent service channel ch0-chn from the high-speed data signal DATA IN that data terminal equipment enters; TAF also plays a part colligator simultaneously, and it will combine with high-speed data signal DATA OUT again from the low speed subsignal that concurrent service channel ch0-chn receives.Therefore, second end in the multichannel data connection, IWF plays a part the high-speed data signal DATAIN that enters is distributed to the distributor of concurrent service channel ch0-chn, and plays a part that colligator-it combines the low speed data signal that receives from the concurrent service channel again with a high-speed data signal DATAOUT.
Protocol architecture shown in Figure 2 is also set up multichannel syndeton shown in Figure 5.In most preferred embodiment of the present invention, the L2R/RLP unit is common for all Traffic Channels of distributing for same connection, and plays a part above-mentioned distributor and colligator.But have its oneself rate adapted (RA) and chnnel coding (FEC) function according to each Traffic Channel of Fig. 2.Thereby from the angle of L2R/RLP unit, multichannel data connects and is connected similar with the single channel data basically." transmitting channel " between the L2R/RLP unit only has than bigger in the past capacity.
Below, describe the operation of L2R/RLP unit in detail.Travelling carriage has an ongoing nontransparent circuit switched data and connects, and this connection is included in one or more Traffic Channel in the system, and this system can carry out the high speed multichannel data and send.The fill level and the throughput that is connected of the L2R/RLP unit continuous monitoring transmission buffer of transmit leg A.When degradation that connects and error number increase, following incident takes place:
1) number of times that resends of rlp frame increases,
2) fill level of transmission buffer reaches the flow control activation level, and flow control obtains activating,
3) number of times that resends of single frame reaches a predetermined maximum value, but this is not considered according to the present invention,
4) throughput of Lian Jieing is reduced to a decision value.This decision value can be certain value between half of current specified user rate and current specified user rate, and can ask bigger channel capacity, with reducing of the data rate of compensation by changing to the single Traffic Channel that more efficiently channel coding schemes causes.
When 2) and 4) when all setting up, the L2R/RLP unit of transmit leg A increases channel capacity and changes to more efficiently channel coding schemes by the CMM PROGRAMMED REQUESTS.If for example using a Traffic Channel at present, then ask second Traffic Channel of same carrier wave.After the channel allocation and CMM program of success, data be sent in original identical or much at one data rate under proceed, but channel coding schemes FEC becomes better.
According to original channel capacity, can come the outer channel capacity of amount of the claim by for example following mode:
| Capacity originally | The overhead provision of being asked |
| ????1 | ????1 |
| ????2 | ????2 |
| ????3 | ????3 |
| ????4 | ????4 |
| ????5 | ????3 |
| ????6 | ????2 |
| ????7 | ????1 |
Under the situation that channel capacity is doubled, the decision value of throughput is different, because in the CMM program with after changing channel coding schemes, can not reach original specified user rate.As a rule, we can say that the percentage of additional Traffic Channel is low more, the decision value of throughput just low more-this decision value is to be used to request to change channel coding schemes and extra channel capacity.
After changing to more efficiently channel coding schemes, the L2R/RLP unit of transmit leg A continues monitoring:
The fill level of-transmission buffer and the throughput that is connected, detecting changing to may needing of more efficiently channel coding schemes and amount of the claim exterior capacity,
The throughput of-connection is to detect the possibility of recovering the higher rate channel and discharge extra channel resource under the situation that radio condition is improved.
This can show by use-case 4.Suppose that having set up a non-transparent data on original user rate is the traffic channel full rate of 9.6kbit/s connects, radio interface speed is 12kbit/s and FEC=1/2.The throughput that connects is reduced to below the predetermined decision value (for example 8kbit/s), and the fill level of transmission buffer reached the flow control activation level, thereby flow control obtains activating.Simultaneously, the resending number of times and may reach predetermined maximum value of single frame, but this is not considered according to the present invention.The L2R/RLP unit asks to have one or more traffic channel full rate of 4.8kbit/s user rate subsequently, radio interface speed and the FEC=1/3 of 12kbit/s.In addition, CMM program of L2R/RLP unit requests, and be changed into such configuration-be that user rate is that 4.8kbit/s, radio interface speed are 12kbit/s and FEC=1/3 by the original Traffic Channel of this CMM program.Subsequently, data are sent in that total rating data speed (specified user rate originally) and the more efficiently channel coding schemes FEC=1/3 with 4.8+4.8kbit/s=9.6kbit/s proceeds on two Traffic Channels.
If can not obtain the additional channel of being asked, data send and proceed with current channel configuration.But the L2R/RLP unit activating reattempts timer.If situation identical after this timer expiration still continues, then increase the new trial of channel capacity, and if new trial failure, timer is then restarted or the like.If the throughput that connects still is lower than a lower predetermined decision value, then the channel coding schemes of each obtainable Traffic Channel is changed to more efficiently one by a CMM program.A reasonably low predetermined decision value is half a value that is lower than original specified user rate.
This can show by use-case 5.Suppose that the original user rate that has ongoing non-transparent data to connect-wherein connect on two parallel Traffic Channels is 19.2kbit/s, the radio interface speed on two Traffic Channels is 12kbit/s, and FEC=1/2.Subsequently, the throughput of connection is reduced to below the 9.6kbit/s, and the fill level of transmission buffer reached the flow control activation level, and flow control obtains activating.The resending number of times thereby can reach a predetermined maximum value of each frame, but this is not considered.There is not available extra traffic channel, CMM program of L2R/RLP unit requests in the case, to make user rate be that 4.8kbit/s, radio interface speed are 12kbit/s and FEC=1/3 thereby this program will change the configuration of current business channel.Subsequently, data are sent on these two Traffic Channels and proceed in conjunction with rating data speed with the low of 4.8+4.8kbit/s=9.6kbit/s, but correspondingly have more efficiently channel coding schemes FEC=1/3.
6.0 the flexible Application in the service of high speed multichannel data
Suppose that mobile station MS has ongoing nontransparent circuit switching connection-this system on one or more Traffic Channel in a system and can carry out the high speed multichannel data and send.In the case, the fill level and the throughput that is connected of the L2R/RLP unit continuous monitoring transmission buffer of transmit leg A.When degradation that connects and error number increase, the number of times that resends of rlp frame increases.In certain stage, the fill level of transmission buffer reaches the flow control activation level, thereby flow control obtains activating.The resending number of times and also may reach predetermined maximum value of single frame, but this is not considered.The throughput that connects is reduced to this below predetermined maximum decision value.The L2R/RLP unit asks to increase the number of radio channel subsequently.If required channel capacity can access, then process as proceeding in above-mentioned 4.0 with describing.If can not obtain the channel capacity of being asked, the decision value of throughput is reduced step by step, and data send and proceed with current channel configuration.If reduce to a new decision value, ask then that corresponding overhead provision-it is less than the overhead provision corresponding with maximum decision value through the throughput of combination.If this overhead provision can obtain, then process is proceeded as described above.If the overhead provision of request can not obtain, throughput value is progressively reduced further, and data send and to proceed with current channel configuration, reaches a new decision value up to throughput.
Though described the present invention in conjunction with some specific embodiment, but it is evident that what this description was just undertaken by example, and under the prerequisite that does not break away from as the determined scope and spirit of the present invention of appending claims, can the embodiment that be announced be replaced and revise.
Claims (14)
1. one kind is carried out the method that non-transparent data sends in digital communication system, may further comprise the steps:
The non-transparent data that foundation has rating data speed, the first transmission capacity and first channel coding schemes is connected;
On connecting, non-transparent data utilize a kind of communication protocol to send data, wherein the correct data frame that receives of this protocol validation and resend the defective Frame that is received with Frame;
With the frame data buffer that will send in a transmission buffer;
The Frame that sends is stored in thinks in this transmission buffer that possible resending prepare,, it is characterized in that up to receiving the affirmation that successfully receives:
Monitor the throughput that non-transparent data connects according to resending number of times,
If the throughput that data connect drops to a predetermined threshold, then more send capacity and more efficiently channel coding schemes for described data connection request.
2. according to the method for claim 1, it is characterized in that
The fill level of monitoring transmission buffer,
Reach a predetermined threshold if the throughput that data connect drops to the fill level of a predetermined threshold and transmission buffer, then more send capacity and more efficiently channel coding schemes for described data connection request.
3. according to the method for claim 1 or 2, it is characterized in that
A more efficiently channel coding schemes is changed in connection to data,
For connecting, data distribute and the corresponding more transmission capacity of this more efficiently channel coding schemes, so that original specified user rate remains unchanged or be almost constant.
4. according to the method for claim 1 or 2, it is characterized in that
If can not obtain the overhead provision of being asked, keep the first transmission capacity and first channel coding schemes, this overhead provision is that more efficiently channel coding schemes is original specified user rate to be remained unchanged or almost constant required.
5. according to the method for claim 2, it is characterized in that
If the extra channel capacity of being asked can not obtain, then keep first channel coding schemes,
If the throughput that data connect increases and if the fill level of transmission buffer does not reduce from described predetermined threshold from described predetermined threshold, then repeat request to more overhead provisions and more efficiently channel coding schemes with the well-regulated time interval,
Be lower than former threshold value if the throughput that data connect is reduced to predetermined second threshold level-this second threshold level, then under the situation of not distributing more transmission capacity, channel coding schemes changed over more efficiently channel coding schemes.
6. according to the method for claim 4, it is characterized in that
If can not obtain the additional transmission capacity of asking, keep first channel coding schemes,
Reduce the described predetermined threshold of throughput,
If also be not reduced to below the described predetermined threshold if the throughput that connects is reduced to the fill level of described threshold value that reduces and transmission buffer, then more send capacity and more efficiently channel coding schemes for described data connection request.
7. any one described method among the claim 1-6 as described above is characterized in that:
One or more Traffic Channel is connected to data as extra transmission capacity allocation.
8. digital communication system, comprise recipient (A) with transmission buffer, recipient (B), nontransparent circuit switched data between transmit leg and recipient connects, channel coding device (FEC) on described data connect, and a communication protocol (RLP) thereby-wherein data send on described data connect with Frame and the correct data frame that receives are confirmed and the defective Frame that receives is resend, the Frame that Frame that described transmission buffer buffering will send and storage send receives a successful confirmation of receipt up to it, it is characterized in that transmit leg (A) or recipient (B) suitably are provided with monitoring the throughput that non-transparent data connects according to resending number of times, and transmit leg (A) or recipient (B) are provided with suitably to reduce under the situation of a predetermined threshold value with the throughput that connects in data and are more sent capacity and more efficiently channel coding schemes for described data connection request.
9. method according to Claim 8, it is characterized in that transmit leg (A) suitably is provided with the fill level with the monitoring transmission buffer, and transmit leg (A) is provided with suitably under the situation that the fill level that falls a predetermined threshold and transmission buffer with the throughput that connects in data increases to a predetermined threshold and is more sent capacity and a more efficiently channel coding schemes for described data connection request.
10. according to Claim 8 or 9 method, it is characterized in that the overhead provision of being asked makes that original specified user data rate remains unchanged or be almost constant after changing to more efficiently channel coding schemes.
11. according to Claim 8 or 9 method, it is characterized in that this method is that the data of a multichannel access mobile communication system-wherein connect a Traffic Channel (ch0) that is included on the radio route, and increase transmission capacity that data connect and comprise half rate is changed over traffic channel full rate.
12. according to Claim 8 or 9 method, it is characterized in that this system is a multichannel access mobile communication system, wherein data connect a Traffic Channel (ch0) or a plurality of Traffic Channel (ch0-chn) that is included on the radio route, and the transmission capacity that the increase data connect comprises the number that increases the Traffic Channel of distributing to this data connection.
13. the method for any one according to Claim 8-12 it is characterized in that transmit leg is the terminal adapting function (TAF) on the travelling carriage (MS), and the recipient is the function that cooperatively interacts (IWF) of mobile communications network.
14. the method for any one according to Claim 8-13 it is characterized in that transmit leg is the function that cooperatively interacts (IWF) of mobile communications network, and the recipient is the terminal adapting function (TAF) of travelling carriage (MS).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 96190476 CN1154190A (en) | 1995-05-09 | 1996-05-08 | Non-transparent data transmission in a digital telecommunications system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI952253 | 1995-05-09 | ||
| CN 96190476 CN1154190A (en) | 1995-05-09 | 1996-05-08 | Non-transparent data transmission in a digital telecommunications system |
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| CN1154190A true CN1154190A (en) | 1997-07-09 |
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| CN 96190476 Pending CN1154190A (en) | 1995-05-09 | 1996-05-08 | Non-transparent data transmission in a digital telecommunications system |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1328867C (en) * | 2000-10-31 | 2007-07-25 | Lg电子株式会社 | Method of packet data transfer with hybrid ARQ |
| WO2009117951A1 (en) * | 2008-03-25 | 2009-10-01 | 华为技术有限公司 | Method, device and system for packet data transmission |
| CN1886968B (en) * | 2003-12-01 | 2010-04-28 | 汤姆逊许可公司 | Device and method for the preparation of sending data and corresponding products |
| CN101174918B (en) * | 2006-11-02 | 2011-05-18 | 索尼株式会社 | Transmitting apparatus, transmitting method, and communications system |
| CN101345709B (en) * | 2008-08-18 | 2012-02-22 | 中兴通讯股份有限公司 | Method for implementing non-transparent data traffic switch and a TD-SCDMA terminal |
| CN101577673B (en) * | 2008-05-09 | 2012-07-11 | 中兴通讯股份有限公司 | Flow control processing method |
| CN111357223A (en) * | 2017-11-16 | 2020-06-30 | 上海诺基亚贝尔股份有限公司 | Method, apparatus and computer program |
-
1996
- 1996-05-08 CN CN 96190476 patent/CN1154190A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1328867C (en) * | 2000-10-31 | 2007-07-25 | Lg电子株式会社 | Method of packet data transfer with hybrid ARQ |
| CN1886968B (en) * | 2003-12-01 | 2010-04-28 | 汤姆逊许可公司 | Device and method for the preparation of sending data and corresponding products |
| CN101174918B (en) * | 2006-11-02 | 2011-05-18 | 索尼株式会社 | Transmitting apparatus, transmitting method, and communications system |
| WO2009117951A1 (en) * | 2008-03-25 | 2009-10-01 | 华为技术有限公司 | Method, device and system for packet data transmission |
| CN101577673B (en) * | 2008-05-09 | 2012-07-11 | 中兴通讯股份有限公司 | Flow control processing method |
| CN101345709B (en) * | 2008-08-18 | 2012-02-22 | 中兴通讯股份有限公司 | Method for implementing non-transparent data traffic switch and a TD-SCDMA terminal |
| CN111357223A (en) * | 2017-11-16 | 2020-06-30 | 上海诺基亚贝尔股份有限公司 | Method, apparatus and computer program |
| CN111357223B (en) * | 2017-11-16 | 2022-09-13 | 上海诺基亚贝尔股份有限公司 | Communication method, device and computer readable storage medium |
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