CN102655687A - Method and system for establishing uplink for wireless cellular communication - Google Patents

Abstract

The invention relates to wireless communication, and particularly relates to wireless grouped data communication. In particular, the waiting time is reduced by respectively distinguishing circuit exchange connection and group switching connection.

Description

The method and system that are used for the up link foundation of radio honeycomb communication

The application be that April 6, application number in 2005 are 200580049397.2 the applying date, denomination of invention divides an application for the application of " being used for the method and system that the up link of radio honeycomb communication is set up ".

Technical field

The present invention relates to radio communication.More particularly, it relates to wireless packet data communication.Especially, it relates to reducing of delay when setting up uplink communication channel.

Background technology

A plurality of users are commonly known in the art to the multiplexing of public resource.FDM (frequency division multiplexing), TDM (time division multiplexing) and CDM (code division multiplexing) are the well known examples of principle of multiplexing.

In addition, known a plurality of queue discipline is used for the business on the dispatching multiplex resource.

" realizing the communication and the application of mass measurement through the UMTS network " of Kenth Fredholm, Kristian Nilsson is (among (Lith-ISY-EX-3369-2003,

2003) the description UMTS (Universal Mobile Telecommunications System) based on the simulation of the voice of IP (Internet Protocol).This Master's thesis comprises the notion such as QoS (service quality), AMR (AMR), RTP (RTP), RTCP (RTCP Real-time Transport Control Protocol) and SIP (session initiation protocol).

AMR can be according to comprising for example 12.2 to 4.75kbit/s various bit rate operations.Ambient noise produces with 1.8kbit/s.The AMR frame comprises AMR head, AMR supplementary and AMR core frames.

-AMR head comprises

* frame type, and

* frame quality indicator.

-AMR supplementary comprises

* pattern indication,

* mode request, and

* CRC parity check bit.

-AMR core frames comprises the comfort noise data or the speech data of the data bit that is divided three classes,

* category-A,

* category-B, and

* C class.

Comfort noise transmits in the category-A bit field.For gained (decoding) voice quality, the speech data of in the category-A position, classifying is to think most important position, and C class position is least important.In UMTS, SCR (source control speed) operation is necessary for AMR, and the control transmission data rate.

RTP supports various low level protocols, but usually through UDP (UDP) operation, as shown in Figure 1.RTP and UDP generally are called the transport layer protocol in the protocol stack as shown in Figure 1.In application layer, the AMR frame of multimedia application sends in RTP divides into groups.Two AMR of Fig. 3 .2 explanation in the Master's thesis launch the general view of the initiation of the end-to-end communication session of passing through the UMTS network between the phone.

" the dispatching algorithm general introduction in the radio multimedium network " (IEEE Wireless Communications of Hossam Fattah, Cyril Leugn; The 76-83 page or leaf; In June, 2002) a plurality of dispatching algorithms have been described, and comprising the scheduling in the cdma network.A kind of algorithm is promptly dispatched CDMA and has been disclosed between BS and the MS in the exchanges data that comprises one or more groupings, carries out in the be called capsule fixed size unit of (capsule).For uplink scheduling, whenever MS has new grouping will transmit the time, the capsule request of transmitting sends to the base station by travelling carriage.For each time slot, scheduler selects capsule to transmit request from the public queue according to priority or delay sensitivity ordering.The base station is sent to selected travelling carriage and is transmitted the permission capsule, to notify them about its capsule delivery time and power grade.

U.S. Patent application US2004/0184461 discloses a kind of packet switched data network that stream mode service is provided, and VSS for example is provided the GPRS network of (voice flow media services), comprise auxiliary VSS server, be the VSS server.The VSS server is collected the information about the communication condition of the various piece of the function of packet switching network and network.When the terminal A that is connected to network wants to set up when being connected with the voice of the second terminal B, it receives the information about the link between base station and the terminal A from its base station during setting up connecting.Information is used to select suitable operator scheme, storage and play mode or streaming.

Third generation partner program (3GPP): technical specification group core network; The 3rd layer of standard of mobile wireless electrical interface, (Release 1998), 3GPP TS 04.08v7.21.0; France; In December, 2003, the rules of regulation Radio Link control RLC, and be defined in the rules that are used for calling controling CC, mobile management MM, radio resource RR, management and session management SM on the radio interface.3.5.2.1.2 trifle has been described the initiation of packet access program and channel request.Travelling carriage through the CHANNEL REQUEST message of scheduling on the RACH transmission and leave packet idle mode, come the initiation packet access program.CHANNEL REQUEST message on the RR entity scheduling RACH of travelling carriage.

Third generation partner program (3GPP): technical specification group GSM/EDGE radio access network; GPRS (GPRS); Travelling carriage (MS)-base station system (BSS) interface; Radio Link control/media interviews control (RLC/MAC) agreement; (Release 1999); 3GPP TS 04.60V8.25.0; France, is defined in the rules that radio interface (reference point Um) is used for general packet radio service gprs, media interviews control/Radio Link control MAC/RLC layer in September, 2004.This document provides comprehensive description of the rlc/mac layer function of GPRS and EGPRS (GPRS and enhancing GPRS) radio interface Um.In this TS, if do not offer some clarification on, then GPRS representes GPRS and EGPRS.Sub-district 7.1.2.1.1 relates to the visit continuation control on the PRACH.PRACH Control Parameter IE comprises visit continuation Control Parameter, and will on PBCCH (Packet Broadcast Control CHannel) and PCCCH (Packet Common Control CHannel), broadcast.The parameter that comprises among the PRACH Control Parameter IE is:

-MAX_RETRANS is for each radio priorities i (i=1,2,3,4);

-PERSISTENCE_LEVEL, it is made up of the PERSISTENCE_LEVEL P (i) of each radio priorities i (i=1,2,3,4), wherein P (i) ∈ 0,1 ... 14,16}.If PRACH Control Parameter IE does not comprise the PERSISTENCE_LEVEL parameter, then this will be interpreted as for all radio priorities, P (i)=0;

-S is used for confirming next tdma frame; And

-TX_INT, its value T are used for confirming next tdma frame.

Travelling carriage will be arranged M+1 the biglyyest, and wherein, M is the reception value of the parameter MAX-RETRANS of certain priority, attempts sending PACKET CHANNEL REQUEST (perhaps EGPRS PACKET CHANNEL REQUEST) message.After sending each PACKET CHANNEL REQUEST (perhaps EGPRS PACKET CHANNEL REQUEST) message, travelling carriage will be monitored complete PCCCH (corresponding to its PCCCH_GROUP).

Travelling carriage will start timer T3186 when the packet access program begins.When timer T3186 expires, will stop the packet access program, to the failure of upper strata indication packet access, and travelling carriage will turn back to packet idle mode.Sending the first time of PACKET CHANNEL REQUEST (perhaps EGPRS PACKET CHANNEL REQUEST) message attempts and can initiate on the first available PRACH piece on the defined PDCH travelling carriage at PCCCH_GROUP.Travelling carriage will adopt even probability distribution to select one of four tdma frames in the selected PRACH piece randomly.For each trial, travelling carriage will adopt even probability distribution set 0,1 ... obtain random value R among the 15}.If P (i) is less than or equal to R, i wherein is the radio priorities of the TBF that is established, then allows travelling carriage to transmit PACKET CHANNEL REQUEST message.After each the trial, S and T parameter are used for definite next tdma frame that can be allowed to attempt continuously therein.Having got rid of the tdma frame that possibly comprise message itself, belonged to the quantity of the tdma frame of the PRACH on the defined PDCH of travelling carriage of PCCCH_GROUP between attempting continuously for twice that sends PACKET CHANNEL REQLEST (perhaps EGPRS PACKET CHANNEL REQUEST) message, is to adopt even probability distribution that each time is transmitted in the set { random value that obtains among the S.S+1....S+T-1}.8.1.2.5 the up link TBF that trifle has been described during the transmission of down link RLC data block sets up.Travelling carriage can come the foundation that the request up link transmits in down link TBF through in PACKET DOWNLINK ACK/NACK message, comprising channel request description information element.Initiation is triggered by the request that is used to transmit LLC PDU from the upper strata.Specify the radio priorities that will be associated with the transmission of dividing into groups from the request on upper strata.When a kind of like this request,

-Ruo allows the visit to network, then Mobile Origination packet access procedure.

-otherwise the RR in the travelling carriage gives this request of layer refusal.

Travelling carriage through on the PACCH in PACKET DOWNLINK ACK/NACK message channel request description information element and start timer, come the initiation packet access process.

3GPP TS 44.060 describes an alternative of the rules among standard 3GPP TS 04.08 and the 3GPP TS 04.60.

Third generation partner program (3GPP): technical specification group GSM EDGE Radio Access Network; GPRS (GPRS); Travelling carriage (MS)-base station system (BSS) interface; Radio Link control/media interviews control (RLC/MAC) agreement (Release 5), 3GPP TS 44.060V5.13.0, France; In September, 2004, regulation comprises that Radio Link control rlc layer and the media interviews of the physical link controlled function of the radio interface between GSM EDGE Radio Access Network GERAN and the mobile station MS control the rules of MAC layer.Uplink state flags USF is used to allow multiplexing from the uplink radio block of different mobile stations on Packet Data Channel PDCH.It is the physical connection of between travelling carriage and network, setting up with the exchange of support information stream that RR (radio resource) connects.TBF (Temporary Block Flow) is made the physical connection of the one-way transmission that is used for supporting LLC (logic link control) PDU on the packet data physical channel by two RR peer-entities in the A/Gb pattern.(the A/Gb pattern is a kind of operator scheme of MS when being connected to core network CN through GERAN and A and/or Gb Interface; The A interface is the interface between BSS (base station sub-system) and the 2G MSC (mobile switching centre), and Gb Interface is the interface between BSS and the 2G SGSN (Serving GPRS Support Node).) in the Iu pattern, TBF is provided for supporting the logic of the one-way transmission of the RLC PDU on the basic physical sub-channels to connect by two MAC entities.(the Iu pattern is a kind of operator scheme of MS when being connected to CN through GERAN or UTRAN and Iu interface; The Iu interface is the interface between BSS or RNC (radio network controller) and 3G MSC or the 3G SGSN.) in extended uplink TBF pattern, up link TBF can keep in the cycle in interim inertia, during this period, the RLC information that travelling carriage will not send.

Travelling carriage through the PACKET CHANNEL REQUEST message on the scheduling PRACH (grouping RACH) corresponding with its PCCCH_GROUP (Packet Common Control CHannel group) transmission and leave packet idle mode simultaneously, come the initiation packet access process.When the response of waiting for PACKET CHANNEL REQUEST message, travelling carriage will be monitored the complete PCCCH (Packet Common Control CHannel) corresponding with its PCCCH_GROUP.In monitoring during complete PCCCH, travelling carriage will be decoded to any incident of the PERSISTENCE_LEVEL parameter that comprises in the message that on PCCCH, is received.When travelling carriage received the PERSISTENCE_LEVEL parameter, the value of PERSISTENCE_LEVEL parameter was considered in will attempting at next PACKET CHANNEL REQUEST subsequently.Parameter PERSISTENCE_LEVEL comprises the continuation grade P (i) of each radio priorities i (i=1,2,3,4), wherein P (i) ∈ 0,1 ... 14,16}.Sending the first time of PACKET CHANNEL REQUEST (perhaps EGPRS PACKET CHANNEL REQUEST) message attempts and can initiate on the first available PRACH piece on the defined PDCH (Packet Data Channel) travelling carriage at PCCCH_GROUP.Travelling carriage will adopt even probability distribution to select one of four tdma frames in the selected PRACH piece randomly.For each trial, travelling carriage will adopt even probability distribution set .1 ... obtain random value R among the 15}.If P (i) is less than or equal to R, then allow travelling carriage to transmit PACKET CHANNEL REQUEST message.Therefore, P (i) is more little, and then continuation is big more.

Travelling carriage generally adopts the slip transmission window of RLC data PDU to operate.In the extended uplink TBF pattern of technical specification 3GPP TS 44.060, if in window, there is not RLC data block to use, then travelling carriage will stop to send RLC data block.When but RLC data block becomes the time spent in window, travelling carriage will continue to send RLC data block.

The UMTS correspondence of TBF among GSM/GPRS and the GSM/EGPRS is RAB (RAB).

Third generation partner program (3GPP): technical specification group GSM EDGE Radio Access Network; Multiplexing and multiple access on the radio path (Release 5); 3GPP TS 45.002v5.12.0; France, has defined the physical channel of supporting the radio subsystem that logic channel is required in April, 2004.It comprises the description of logic channel and the definition of frequency hopping, TDMA (time division multiple access) frame, time slot and burst (burst).Except going up in the uplink portion of channel of PACCH (grouping associated control channel) of transmission at PRACH (grouping RACH) or CPRACH (compact grouping RACH) as access burst, logical channel type will be indicated through the type of message that comprises in the piece head part.For the PACCH that transmits as access burst, logical channel type is indicated through polling message corresponding on the down link.For the situation of PRACH or CRPACH, logical channel type is indicated through the USF of block-by-block setting on down link.

The MAC layer is responsible for coming the shared data and the common communication resource (air interface) of voice user according to allocation strategy.

In GSM/GPRS for example; The MAC of BSS (base station sub-system) is in charge of through available time slot, belongs to the up link and the downlink scheduling of the RLC piece of different TBF; Thereby solve because the conflict of for example asking conflict to cause; When having available time slot, up link TBF is distributed to request MT (portable terminal), informing uplink TBF cancellation distributes when MT is inertia in predetermined period, relevant voice is called out be associated with a pair of time slot; And the signal that sends cancellation distribution T BF as required, so that time slot is to can be used for voice communication.At uplink direction, the MAC of MT is responsible for initiating the transmission of up link TBF to the request that is used to transmit the data of not setting up TBF yet of BSS.In case TBF sets up and is identified, the MAC of MT transmits the RLC PDU that carries one or more segmentation LLC PDU through the BSS distributed time slot.MT proceeds to send, and up to other data that will not send, perhaps it has transmitted the RLC piece of the maximum quantity that is allowed.Discharge TBF then.By network each TBF is distributed an interim stream identification code TFI, it all is unique on both direction.

Fig. 2 schematically shows segmentation/reorganization of LLC PDU and RLC PDU.LLC PDU comprises frame headers " FH ", LLC data or control information " information field " and Frame Check Sequence " FCS ".Radio blocks comprises: 1 byte MAC head " BH " is RLC data " information field " or RLC/MAC controll block " information field " afterwards, is 16 block check sequences " BCS " at last.Radio blocks carries through four conventional bursts on physical channel.

The document of more than quoting is open to allow when Mobile Origination PS establishment of connection channel request immediately.

Summary of the invention

A common problem of multi-address system is the various requirement that will satisfy session, for example QoS.Another problem is how under the situation of communication resource distribution business and scheduled transmission, to combine these requirements.

In multi-user access, delay or stand-by period be key issue often.When real-time application (like voice) being provided, be urgent to the needs of lacking delay or low latency through the packet switching connection.Such example application is " Push to talk over Cellular " (Push-to-talk over Cellular), PoC.

In general; For example, certain just obtains the response that presses the button after postponing as the user; Although perhaps the opposing party has shut up and awaiting acknowledgement but still when his speech message is sent to during conversing, this type situation is a problem on uplink direction especially.Remembeing, in typical existing system, is that the network side of wireless connections is responsible for TBF foundation.

Therefore, needing provides the uplink communication channel scheduling of packet data transmission for the user effectively and sets up, and said user is temporarily inactive when wireless transmission, then gets into active state.

The uplink communication channel that an object of the present invention is to reduce when subscriber equipment or user get into active state is set up the required time.

Another purpose is to set up definite channel request time that provides for TBF.

Another purpose provides and is used for dispatching effectively and set up up link TBF, or the method and system of the corresponding incident of various communication system.

Another purpose provides the method and system that make effective uplink communication channel of PoC and foundation.

At last, a purpose provides the method and system of setting up with the irrelevant packet switched uplink communications channel of delay timer.

These purposes are set up through uplink scheduling or uplink communication channel and are reached with the method and system of relevant signaling.

Description of drawings

Fig. 1 illustrates the protocol stack of the RTP with bearing multimedia application, UDP and IP transmission and network protocol layer according to prior art substantially.

Fig. 2 schematically shows the segmentation/reorganization according to the LLC PDU and the RLC PDU of prior art.

Fig. 3 illustrates the block diagram according to the device of the first embodiment of the present invention.

Fig. 4 illustrates the block diagram of device according to a second embodiment of the present invention.

Embodiment

For postponing sensitive application, it is important having low latency.

In multi-user access, delay or stand-by period be key issue often.When real-time application (like voice) being provided, be urgent for the needs of lacking delay or low latency through the packet switching connection.A kind of such example application is " Push to talk over Cellular " PoC.

For example the toll telephone of PoC (toll) quality requirement postpones to reduce.The present invention provides this delay to reduce.For example also will improve Web browsing based on honeycomb.

The present invention recognizes that if subscriber equipment or user do not have to utilize the TBF that has set up, then TBF discharges according to release standard known in the art, and needs to initiate again.Initiation comprises sends one or more channel request message.If the required time of channel request can reduce, then delay and stand-by period can reduce.In this respect, prior art solutions comprises that the TBF of undue delay sets up.

In order further to reduce to postpone and the stand-by period, according to the present invention, transmitting and scheduling preferably continues.The USF mark is then than adopting conventional the transmission when dispatching to be sent out more continually; Compare with the situation that adopts relatively poor conventional non-continuous dispatching to use when of the present invention; Even through optimizing; This also can increase on one's own initiative can receiving scheduling information to travelling carriage requirement, increased power consumption thus to a certain extent.Advantage that is realized is that the entity of subscriber equipment or user then can once send the piece of greater number, and need not other entity of waiting for that subscriber equipment is possible.

In general, the delay up link TBF of prior art is based upon uplink direction and is a problem especially.Make progress at downlink side, data are transmitted to a plurality of users in the base station, and resource can be effectively relatively the transmit leg information available distribute and dispatch (wireless user equipment is not had propagation time delay).

When subscriber equipment or user become inertia, from rather than transmit data but possibly receive data the time, the TBF that early sets up that is used to transmit data is released, only if new data arrive in the time frame of about several seconds.If subscriber equipment or user become activity after this time frame, data arrives then, then TBF need rebulid.Foundation needs the time.Have realized that average retardation can be reduced about 60-113 millisecond through TBF foundation according to the present invention and scheduling.For two sides that participate in conversation through similar connection, perceived effect doubles.Effect is very significant.For example for the voice communication among the PoC and based on the Web browsing of honeycomb the time, situation is especially true.

The present invention recognizes that packet switching connects and TBF foundation employing is initiated according to the channel request of the channel request message that subscriber equipment sent.Circuit switching connects also needs channel request.According to the present invention; Connect for circuit switching, reach random distribution postpone before channel request message not, still; When communicating through cellular radio communication system; Connect for packet switching, channel request message is sent out immediately, and can not wait for and random distribution time delay time corresponding.

The present invention depends on the following fact: connect for circuit switching, (like call) only set up a connection for whole communication session usually.Random time postpones to have increased the time delay of call setup, and within the scope of 0-226 millisecond, this is difficult to noticed by the user usually.Through adopting random delay, the conflict of channel request has obtained solution in the time of from different user.In addition, if two initial channel request messages overlap in time, then repeated channel request does not overlap most probably, and connects and can be established.

But, connect for packet switching, observe, for the communication session of user institute perception, often need an above channel request message.Example communication session comprises that Web browsing communicates by letter with push-to-talk.

When carrying out Web browsing, the user possibly be interrupted or become and be busy with reading the information that obtains.Read or because any former thereby when becoming activity once more, possibly need TBF to set up again when the user accomplishes, this depends on whether the TBF that early sets up discharges (having depended on elapsed time since the information that request early obtains).In most systems, be released after the time frame of TBF within scope is the several seconds (as 1.5 seconds).Under the situation that packet switching connects, postponing to reduce is that the reduction collision risk is preferred, because user that the for example request of sending is upgraded or user use and will more can not let most of user be fed up with than big stand-by period and long response time.

A similar reason is applicable to the session of example buttons airtime communication.Under an explanation sample situation of the present invention;, receive the user and respond received information then for first user who connects through the packet switching in the cellular radio communication system to the one or more users that its information offered this information of reception has set up TBF/ packet switching connection.If first user wants to provide out of Memory then, then the duration of one or more responses possibly surpass the scheduled time of first user's TBF release, and when first user wants out of Memory is provided, must rebulid TBF.Therefore, be necessary for first user and rebulid TBF so that information to be provided.We conclude; For most of user; The time delay that reduces is that the reduction collision risk is preferred; Because there is very little risk in conflict, and the inconvenience (promptly unlikely) of conflict generally be big postpone with the stand-by period preferred, especially true when enough little and feasible conflict of stand-by period becomes obviously (even unlikely) very soon to user or user's application at least.

When the present invention was applied to gsm system, the timer T3120 of a preferred embodiment of the present invention control 3GPP standard connected circuit switching and comprises random delay time, and the packet switching connection is predefined for zero.According to another embodiment, timer T3120 comprises random delay time all the time, and still, timer is applied to the circuit switching connection and is not applied to the packet switching connection.The delay of the channel request message that is connected with the circuit switching of domestic consumer is compared, and therefore the time delay that TBF sets up can reduce the 60-113 millisecond usually.

Fig. 3 illustrates the block diagram of the device " App1 " according to the first embodiment of the present invention.Processing unit " μ 1 " is initiated one or more up links " UL " TBF, and transceiver components wherein " T1 " transmits one or more channel request message afterwards as required at " the Cl1 μ " of check timer " Cl1 " process.When initiating the circuit switching connection, timer " Cl1 " also provides " Cl1 μ " timing information of channel request.It is that circuit switching connects or packet switching connects the delay of confirming by different way that timer " Cl1 " provides according to connection.Preferably, the delay " Cl1 μ " that provides of timer " Cl1 " connects for packet switching and equals zero.Connect for circuit switching, timer preferably provides pseudorandom time of delay.Preferably, pseudorandom distributes with rectangular mode time of delay, promptly has the rectangular probability density function or the rectangle probability distribution that quantize length of delay.

Fig. 4 illustrates the block diagram of device " App2 " according to a second embodiment of the present invention.When initiating the circuit switching connection, timer " Cl2 " is provided for " Cl2 μ " timing information of channel request to processing unit " μ 2 " according to request " Cl2 μ ".Emitter element wherein " T2 " transmits one or more channel request message.Timer preferably provides pseudorandom time of delay.Preferably, pseudorandom distributes with rectangular mode time of delay.Through transceiver components " T2 " do not check timer " Cl2 " " the Cl2 μ " of process just transmit one or more channel request message, processing unit " μ 2 " initiates one or more up links " UL " TBF or packet switching connects.

In present patent application, used the acronym such as IP, UDP, RTP, SIP, TBF, RAB, BSS, MT, MS, GSM, GPRS, EGPRS, UMTS or CDMA2000.But, the invention is not restricted to have system with the entity of these acronyms, but all systems that are suitable for moving in a similar manner.

The invention is not restricted to the embodiment of above detailed description.Within the scope of the invention, can change and revise.The interior all modifications of scope of following claim is contained in the present invention.

Claims (24)

1. the method set up of the up link in the radio honeycomb communication is characterized in that, connects and initiates to postpone according to connection type.

2. the method for claim 1 is characterized in that, the delay that said connection is initiated comprises the delay of channel request message.

3. the method for claim 1 is characterized in that, said connection is initiated to be postponed for the circuit switching connection, and is not postponed for the packet switching connection.

4. method as claimed in claim 2 is characterized in that, said channel request message connects for circuit switching and postponed, and is not postponed for the packet switching connection.

5. according to claim 1 or claim 2 method is characterized in that, said delay is embodied as to connect for circuit switching and comprises the pseudorandom time delay, comprises definite time delay and connect for packet switching.

6. method as claimed in claim 5 is characterized in that, said definite time delay equals zero.

7. method as claimed in claim 5 is characterized in that, said pseudorandom time delay has rectangular probability density function or rectangle probability distribution.

8. according to claim 1 or claim 2 method is characterized in that said cellular communication system is the gsm system with GPRS or EGPRS.

9. method as claimed in claim 8 is characterized in that, connects for packet switching and ignores timer T3120.

10. method as claimed in claim 8 is characterized in that, timer T3120 is arranged to equal zero for the packet switching connection.

11. the device that the up link in the radio honeycomb communication is set up is characterized in that, comprises the processing unit that is used to connect initiation, said processing unit is configured to postpone said connection according to connection type and initiates.

12. device as claimed in claim 11 is characterized in that, comprises the transfer member that is used to transmit one or more channel request message, the delay that said connection is initiated comprises the delay of channel request message.

13. device as claimed in claim 11 is characterized in that, said connection is initiated to be postponed for the initiation that circuit switching connects, and the initiation that connects for packet switching is not postponed.

14. device as claimed in claim 12 is characterized in that, said channel request message connects for circuit switching and is postponed, and is not postponed for the packet switching connection.

15., it is characterized in that like claim 11 or 12 described devices, comprise timer, be used for circuit switching is connected generation pseudorandom time delay and packet switching is connected the definite time delay of generation.

16. device as claimed in claim 15 is characterized in that, said definite time delay equals zero.

17. device as claimed in claim 15 is characterized in that, said pseudorandom time delay has rectangular probability density function or rectangle probability distribution.

18., it is characterized in that like claim 11 or 12 described devices, comprise timer, be used for circuit switching is connected generation pseudorandom time delay and packet switching is connected not generation time delay.

19., it is characterized in that said cellular communication system is the gsm system with GPRS or EGPRS like claim 11 or 12 described devices.

20. device as claimed in claim 19 is characterized in that, connects for packet switching and ignores timer T3120.

21. device as claimed in claim 19 is characterized in that, timer T3120 is arranged to equal zero for the packet switching connection.

22., it is characterized in that said device is subscriber equipment or travelling carriage or is included in them like claim 11 or 12 described devices.

23. a communication system is characterized in that, said communication system comprises and is used for realizing the processing unit like each described method of claim 1 to 10.

24. a communication system is characterized in that, said communication system comprises a plurality of like each described device in the claim 11 to 22.

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