WO2007079772A1

WO2007079772A1 - Gprs/egprs channel establishment using temporary block flow parameters stored in a mobile station

Info

Publication number: WO2007079772A1
Application number: PCT/EP2006/000102
Authority: WO
Inventors: David Cooper; Mungal Dhanda
Original assignee: Matsushita Electric Industrial Co. Ltd.
Priority date: 2006-01-09
Filing date: 2006-01-09
Publication date: 2007-07-19

Abstract

The invention relates to a method in a packet-switched mobile communications system for establishing an uplink temporary physical channel between a mobile station and a network. The method comprises the steps of the mobile station requesting to assign an uplink temporary physical channel, which the network assigns. The mobile station stores the parameters of the uplink temporary physical channel used and transmits data to the network using the assigned uplink temporary physical channel with the stored parameters of a previously used uplink temporary physical channel. The invention further relates to a method in a packet-switched mobile communications system for establishing a downlink temporary physical channel between a network and a mobile station using an assigned downlink temporary physical channel with stored parameters of a previously used downlink temporary physical channel.

Description

GPRS/EGPRS CHANNEL ESTABLISHMENT USING TEMPORARY BLOCK FLOW PARAMETERS STORED IN A MOBILE STATION

The invention generally relates to mobile communications and in particular to increasing a peak data rate at the air interface of GPRS/EGPRS.

The invention concerns a method in a packet-switched mobile communications system for establishing an uplink temporary physical channel between a mobile station and a network without adding further to the signaling load. This invention proposes a method for reducing the signalling overhead when assigning uplink resources, thereby improving downlink data transfer rate.

In response to customer demand for wireless Internet access — and as a stepping-stone to 3G networks — General Packet Radio Service (GPRS) has been introduced. This technology increases the data rates of existing GSM (Global System for Mobile communications) networks, allowing transport of packet-based data. New GPRS handsets are able to transfer data at rates much higher than the 9.6 or 14.4 kbps available to GSM mobile phone users. Under ideal circumstances, GPRS could support rates to 171.2 kbps, surpassing ISDN (Integrated Services Digital Network) access rates. Unlike circuit-switched 2G technology, GPRS is an "always-on" service.

General packet radio service (GPRS) gives GSM subscribers access to data communication applications such as e-mail, corporate networks, and the Internet using their mobile phones. The GPRS service uses the existing GSM network and adds new packet-switching network equipment.

Existing GSM networks use circuit-switched technology to transfer information (voice or data) between users. However, GPRS uses packet switching, which means there is no dedicated circuit assigned to the GPRS mobile phone. A physical channel is established dynamically, only when data is being transferred. Once the data has been sent, the resource (a timeslot on the air interface) can be re-allocated to other users for more efficient use of the network. The definition of GPRS (General Packet Radio Service) system is such that a change of resources assigned to the mobile is achieved through explicit signalling. This means there is a large amount of signalling overhead, especially on the downlink when the uplink resources are assigned and de-assigned quite regularly.

RLC (Radio Link Control) is responsible for a number of functions:

• Transferring LLC-PDUs (Logical Link Control - Packet Data Unit) between the LLC layer and the MAC (Medium Access Control) function;

• Segmentation of LLC-PDUs into RLC data blocks and re-assembly of RLC data blocks to fit into TDMA (Time Division Multiple Access) frame blocks;

• Segmentation and re-assembly of RLC/MAC control messages into RLC/MAC control blocks; and

• Backward error correction for selective transmission of RLC data blocks.

The RLC segmentation function is a process of taking one or more LLC-PDUs and dividing them into smaller RLC blocks. The LLC-PDUs are known collectively as a Temporary Block Flow (TBF) and are allocated the resources of one or more Packet Data CHannels (PDCH). The TBF is temporary and is maintained only for the duration of the data transfer. Each TBF is assigned a Temporary Flow Identity (TFI) by the network.

The RLC data blocks consist of an RLC header, an RLC data unit, and spare bits. The RLC data block along with a MAC header may be encoded using one of four defined coding schemes. The coding scheme is critical in deciding the segmentation process.

MAC controls the access signalling across the air interface, including the management of shared transmission resources (assignment of the radio block to multiple users on the same timeslot). MAC achieves these functionalities by placing a header in front of the RLC header in the RLC/MAC data and control blocks. The MAC header contains several elements, some of which are direction-specific, referring to the downlink or uplink. The key parameters of MAC header are:

• Uplink Status Flag (USF), which is sent in all downlink RLC/MAC blocks and indicates the owner or use of the next uplink radio block on the same timeslot;

• Relative Reserved Block Period (RRBP), which identifies a single uplink block in which the mobile phone will transmit control information;

• Payload Type (PT), which specifies the type of data (control block or data block) contained in the remainder of the RLC/MAC block; and

• Countdown Value (CV), which is sent by the mobile to allow the network to calculate the number of RLC data blocks remaining in the current uplink TBF.

In the following paragraph transmission at the BSS (Base Station System) is explained. The data is sent over the physical layer connection between the SGSN (Serving GPRS Support Node) and BSS. Next the BSSGP (Base Station System GPRS Protocol ) at the BSS sends all of this information to the RLC. The most important job of the RLC layer is segmentation of LLC blocks into smaller RLC blocks. A group of LLC blocks, which has been segmented into smaller blocks, is known as a TBF. Each TBF is allocated resources on the air interface on one or more Packet Data Traffic CHannels (PDTCH). As noted earlier, the TBF is temporary and maintained only for the duration of the data transfer. The TBF is assigned a TFI (temporary flow identity), and the RLC layer adds a header to the data blocks containing the TFI, RLC block sequence number, last block indication, TLLI (Temporary Logical Link Identity), and other information. The RLC header includes direction (downlink/uplink) information as well.

One determination that must be made is the "size" of information inside the RLC data blocks, in other words, the size of the segments of the LLC blocks converted into RLC blocks. The LLC data block segment size will depend on the coding scheme used on the air interface.

There are four coding schemes defined for GPRS: CS1 , CS2, CS3, and CS4, which contain maximum data of 22, 32, 38, and 52 octets correspondingly. The selection of coding scheme depends upon trade-off between desired throughput and reliability.

After the RLC segmentation and header insertions, the RLC blocks are transmitted over the air interface. It is noted that there is one more layer before the physical radio interface — the MAC. This layer controls the access signalling, including assignment of uplink and downlink blocks. It adds its own header, which is monitored by the mobile phones.

The data is transmitted over the air interface to the Mobile Station (MS) via the physical layer. The data then moves up the MS protocol stack where the headers are stripped off at each successive layer. Finally, the original (e.g. e- mail) message is received at the application layer by the mobile user.

The physical connection between the MS and the BSS for the duration of the link of packet data transfer is called the temporary block flow (TBF). The most important job of the RLC layer is segmentation. The RLC layer takes one or more LLC blocks and segments them into smaller RLC blocks. These LLC blocks together are known as a TBF (temporary block flow). Thus, a TBF is a physical connection used by the two radio resource entities to support the unidirectional transfer of LLC PDUs on packet data physical channels. All of the LLC frames that have been segmented for one NPDU (Network Packet Data Unit) form one TBF on the logical link on the air interface. Each TBF is allocated resources on the air interface on one or more PDTCH. The TBF is temporary and is maintained only for the duration of the data transfer. The TBF is "open" during the data transfer and "closed" when the transfer is discontinued.

RLC data blocks are transferred using a process called acknowledged RLC/MAC mode. This process is controlled by a selective ARQ (Automatic Repeat Request) mechanism and by the numbering of the RLC data blocks within a temporary block flow. The uplink data transfer is described first. The sending side, either the Mobile Station or the network, transmits blocks within a window, and the receiving side sends a packet uplink ack/nack (acknowledged/ not acknowledged) or packet downlink ack/nack message as needed. Every such message acknowledges all correctly received RLC data blocks up to an indicated Block Sequence Number (BSN), thus "moving" the beginning of the sending window on the sending side.

The packet ack/nack message contains a bit map of the RLC block sequence numbers, with each bit representing the received status of the data block (0 = nack or not acknowledged; 1 = ack or acknowledged). The message also provides the starting absolute BSN value for the bit map. For example, if RLC data blocks with BSN numbers 21 through 26 have been sent by the mobile and blocks 24 and 25 are corrupted, when the network sends the ack/nack message, it will indicate which blocks were received and which were not. The bit map will appear as "111001 ," beginning with a "1" acknowledging BSN 21 and including a "0" each for BSNs 24 and 25.

The ack/nack message can be sent in any of the assigned blocks, and the RLC/MAC header will indicate that this is a control message. A mobile has a transmit window of only 64 blocks, and if it doesn't receive an ack/nack message within this window, it will notify the network in the next available block that the window is stalled.

The mobile also sends a "countdown value" (of 0 - 15) in the uplink RLC data block header to inform the network how many RLC data blocks remain in the current uplink TBF. Once the countdown value reaches 0, the network can send the final ack/nack message.

After the mobile sends the last data block with a countdown value of 0, it starts a timer. When the timer expires after 5 seconds, the mobile considers the current assignment of resources invalid.

For downlink packet data transfer the network initiates transmission of a packet to a mobile in the ready state using a packet downlink assignment message. If an uplink packet transfer is already in progress, the packet downlink assignment message can be transmitted on a PACCH. Otherwise, it can be sent on a PCCCH or a CCCH. The packet downlink assignment message conveys information to the mobile about the timeslots, the frequency parameters, timing advance, power control, TFI, and starting TDMA frame number. The network sends the RLC/MAC blocks belonging to a TBF on the assigned downlink channels. Generally more than one mobile station is multiplexed on the PDCHs at any given time, and each mobile station needs a way to identify its own TBF. This is done with the TFI in the RLC header. The TFI is a unique identity associated with a TBF in one direction on one set of PDCHs. The MAC header identifies the RLC block as a control/data block, and the TFI in the RLC header identifies the mobile to which the block belongs.

The MAC header in the downlink RLC blocks contains a bit for polling the mobile. It uses an information field such as RRBP to inform the mobile of the relative frame number (and thus the radio block) after which the mobile has to send the packet downlink ack/nack message. There is also a Final Block Indicator (FBI) bit in the downlink RLC header that flags the final RLC data block and initiates the release of resources process. On receiving this final ack/nack message from the mobile, the network starts a timer (value not defined in the GPRS specifications), and when this timer expires, the TFI and all resource assignments to the mobile are released.

It is possible for the network to change a current downlink assignment by using a packet downlink assignment message or a packet timeslot reconfigure message, which in turn has to be acknowledged by the mobile in a reserved radio block on the uplink.

Whenever the network needs to assign packet resources to the mobile station, network has to send explicit control message to assign packet resource [3GPP TS 44.060 V6.15.0 (2005-11 ), GPRS: MS - BSS interface, RLC/MAC protocol (Release 6), p. 25 - 28]. Each control message occupies one radio block. If the packet resources need to be assigned regularly then such control messages can consume a large percentage of the packet resources.

With situations where volume of downlink data transfer is substantially large compared to uplink data transfer, such as during downlink FTP (File Transfer Protocol) or e-mail download. In this situation the resource assignments for the downlink direction are fairly constant and generally not released. But the resource assignments for the uplink direction are released and reassigned regularly. The re-assignment of uplink resources consume downlink packet resources which can not be used for downlink data [3GPP TS 44.060 V6.15.0 (2005-11 ), GPRS: MS - BSS interface, RLC/MAC protocol (Release 6), p. 58 - 59].

The general process of assigning uplink resources is shown in Figure 1 [3GPP TS 44.060 V6.15.0 (2005-11), GPRS: MS - BSS interface, RLC/MAC protocol (Release 6), p. 85 - 93]. During uplink TBF (Temporary Block Flow), steps 3 and 4 may be repeated a number of times depending on the amount of data the mobile station has to transmit. Once the uplink TBF is released, the mobile station and network have to repeat steps 1 , 2, 3 and 4 to establish a new uplink TBF and transfer uplink data.

While the request for new resources from the mobile station is generally carried within a downlink ack/nack (Acknowledged/Not Acknowledged) message, the request does not consume uplink resources, but the assignment from the network consumes one radio block's worth of resources and this radio block is not shared for any other information.

The result is that every time the network sends an assignment message to the mobile station it is prevented from sending up to 148 octets - each radio block can carry two RLC (Radio Link Control) data blocks using MCS 9 and each RLC data block is up to 74 octets - of user data to the mobile station.

The object of the invention is to reduce the number of times an uplink assignment message needs to be sent to a mobile station, hence increasing capability for sending downlink data.

The object is solved by the subject matter of the independent claims. Advantageous embodiments of the invention are subject matters to the dependent claims.

To achieve this object, the present invention provides a method, system, apparatus and computer-readable medium for establishing an uplink temporary physical channel between a mobile station and a network in a packet-switched mobile communications system. The mobile station requests to assign an uplink temporary physical channel, which is assigned to it by the network. The Mobile station stores parameters of the uplink temporary physical channel used and transmits data to the network using the assigned uplink temporary physical channel with the stored parameters of a previously used uplink temporary physical channel.

According to an advantageous embodiment the method further comprises the step of the mobile station releasing the uplink temporary physical channel.

In another embodiment of the invention the network acknowledges data after the mobile station has transmitted it.

An advantageous aspect of the invention is that the parameters include at least one of frequency, timeslots, temporary flow identity, timing advance and uplink state flag.

According to another advantageous embodiment the packet-switched mobile communication system is operated as a GPRS or EGPRS system.

In a further advantageous embodiment the uplink temporary physical channel is a temporary block flow used by the mobile station and the network to support unidirectional transfer of upper layer information.

A further embodiment of the invention relates to the network signalling to the mobile station to use the uplink temporary physical channel with the parameters stored in the mobile station.

A further advantageous embodiment of the invention has bit sequences used to signal to the mobile station being a supplementary polling bit or EGPRS supplementary polling bits.

In another advantageous embodiment the supplementary polling bit or EGPRS supplementary polling bits are set to ¹O'.

Further it is an advantage that the bit sequences used to assign a temporary physical channel to the mobile station are relative reserved block period bits. Another advantageous embodiment of the invention is that the relative reserved block period bits are set to indicate that the most recently, the second most recently or the third most recently stored parameters are used.

In a further advantageous embodiment the mobile station deletes the stored uplink temporary physical channel parameters upon returning to idle state.

In a further embodiment of the invention a method in a packet-switched mobile communications system for establishing a downlink temporary physical channel between a network and a mobile station is used. The network requires a downlink temporary physical channel, which it assigns to the mobile station. The mobile station stores parameters of the downlink temporary physical channel used and the network transmits data to the mobile station using the assigned downlink temporary physical channel with the stored parameters of a previously used downlink temporary physical channel.

Further features and advantages will become apparent from the following, and more particular description of the various embodiments of the invention as illustrated in the accompanying drawings, wherein:

Figure 1 shows a generic uplink resource assignment procedure;

Figure 2 illustrates a GPRS MAC Header;

Figure 3 shows an EGPRS MAC Header;

Figure 4 shows an optimised uplink resource assignment procedure;

Figure 5 is a flow chart for downlink TBF assignment with and without stored parameters; and

Figure 6 is a flow chart for uplink TBF assignment with and without stored parameters.

The following paragraphs will describe various embodiments of the invention. For exemplary purposes only, most of the embodiments are outlined in relation to a GPRS communication system and the terminology used in the subsequent sections mainly relates to the GPRS terminology. However, the used terminology and the description of the embodiments with respect to a GPRS architecture is not intended to limit the principles and ideas of the inventions to such systems.

Also the detailed explanations given in the Technical Background section above are merely intended to better understand the mostly GPRS specific exemplary embodiments described in the following and should not be understood as limiting the invention to the described specific implementations of processes and functions in the mobile communication network.

The following paragraphs will describe various embodiments of the invention, including a method for assigning a downlink TBF, and illustrates further, alternative, configurations.

All downlink RLC/MAC (Medium Access Control) blocks contain a two bit field called the Relative Reserved Block Period (RRBP), as shown in Figure 2 and Figure 3. The RRBP field is only valid if S/P (Supplementary/Polling) bit is not set to 0 within the GPRS MAC header or the ES/P (EGPRS S/P) bit is not set to 00 within the EGPRS MAC header [3GPP TS 44.060 V6.15.0 (2005-11), GPRS: MS - BSS interface, RLC/MAC protocol (Release 6), p. 170 - 171].

In the case of GPRS, there are four combinations of RRBP and S/P bit sequences that are not used as shown in Table 1. In the case of EGPRS, there are four combinations of RRBP and ES/P bit sequences that are not used as shown in Table 2. Currently the RRBP field is used to indicate the amount of time the mobile station has to respond to a poll request. If the mobile station is not polled then the RRBP field is ignored by the mobile station.

Table 1 GPRS RRBP and S/P bit sequences

Table 2 EGPRS RRBP and ES/P bit sequences

There are 4 bit patterns not used in the case of GPRS and EGPRS (see Table 1 and Table 2). One or more of these bit patterns could be used by the network to signal other information to the mobile station. The definition of one bit pattern from GPRS and one bit pattern from EGPRS would need to be kept as it is currently defined. This bit pattern would imply no reaction from the mobile station. For example, for GPRS when RRBP = 00 and S/P=0 then no reaction expected from the MS in relation to these two fields. Similarly, for EGPRS when RRBP = 00 and ES/P = 00 then no reaction is expected from the MS in relation to these two fields. It is possible to define other value or values of RRBP which would expect no reaction from the mobile station.

The invention is that when a mobile station is assigned uplink TBF resources, it is instructed to save a record of the TBF parameters describing the assignment of these resources when the uplink TBF is released and a downlink TBF is active. When the mobile station requests new uplink TBF resources from the network, the network could tell the mobile station to use the previously stored uplink TBF parameters. The network would signal this to the mobile station by using a specific RRBP pattern, with S/P=0 in case of GPRS and ES/P=00 in case of EGPRS. For example, it can be defined that RRBP=OI , and either S/P=0 in the case of GPRS or ES/P=00 in the case of EGPRS, means the mobile station shall use the previously stored uplink TBF parameters. The new procedure for assigning uplink TBF resources is shown in Figure 4.

In this case the mobile station is instructed to store the uplink TBF parameters before the TBF is released. The mobile station requires an uplink TBF after some time and sends a request to the network. The network this time sends a downlink radio block containing other information, such as a downlink RLC data block, and sets the S/P and RRBP bits in such a way that it instructs the mobile station to use the stored uplink TBF parameters. The mobile station then activates the uplink TBF and transfers data as normal.

Figure 6 is a flow chart of the method described above. The method starts with step 600, and then in step 610 the mobile station requests an uplink TBF of the network. Depending on whether the mobile station has stored uplink TBF parameters the network instructs the mobile station to use the stored uplink TBF parameters in step 630, or the network assigns an uplink TBF to the mobile station in step 640 and then the mobile station stores the uplink TBF parameters in step 650.

In step 660 the mobile station transmits the uplink data to the network, which acknowledges this in step 670. If all TBFs are to be released in step 680 the mobile station clears all stored TBF parameters in step 690 and then returns to the beginning. Otherwise the method starts from the beginning in step 600 again.

The method described above can also be applied to the case of downlink TBF assignment. Figure 5 is a flow chart describing this method. It starts with step 500 and then in step 510 the network requires the downlink TBF. If the mobile station has stored TBF parameters in step 520, the network instructs the mobile station to use the stored downlink TBF in step 530. If, however, the mobile station has not got any downlink TBF parameters stored in step 520, the network assigns a downlink TBF to the mobile station in step 540. The mobile station then stores the downlink TBF parameters in step 550.

After the instruction to use the stored downlink TBF or assignment of a downlink TBF the network transmits the downlink data in step 560, which the mobile station acknowledges in step 570. If it is decided in step 580 that all TBFs are to be released, the mobile station clears all stored TBF parameters in step 590 and the method returns to the beginning, otherwise the method restarts with the TBF parameters in the storage section of the mobile station.

A further extension is that other values of RRBP than RRBP =01 could be used (when S/P or ES/P =0 ) to indicate previously stored parameters. For example, usage could be:

RRBP=OI Use most recently stored uplink TBF parameters

RRBP=IO Use 2nd most recently stored uplink TBF parameters

RRBP=11 Use 3rd most recently stored uplink TBF parameters.

Another embodiment of the invention relates to the implementation of the above described various embodiments using hardware and software. It is recognized that the various above mentioned methods as well as the various modules described above may be implemented or performed using computing devices (processors), as for example general purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, etc. The various embodiments of the invention may also be performed or embodied by a combination of these devices.

Further, the various embodiments of the invention may also be implemented by means of software modules which are executed by a processor or directly in hardware. Also a combination of software modules and a hardware implementation may be possible. The software modules may be stored on any kind of computer readable storage media, for example RAM, EPROM, EEPROM, flash memory, registers, hard disks, CD-ROM, DVD, etc.

Claims

1. A method in a packet-switched mobile communications system for establishing an uplink temporary physical channel between a mobile station and a network, the method comprising the steps of:

requesting by the mobile station to assign an uplink temporary physical channel;

assigning to the mobile station by the network the requested uplink temporary physical channel;

storing parameters of the uplink temporary physical channel used by the mobile station; and

transmitting data to the network by the mobile station using the assigned uplink temporary physical channel with the stored parameters of a previously used uplink temporary physical channel.

2. The method according to claim 1 further comprising the step of releasing by the mobile station the uplink temporary physical channel.

3. The method according to any of claims 1 or 2 further comprising the step of acknowledging data by the network after transmitting data by the mobile station.

4. The method according to any of claims 1 to 3, wherein the parameters include at least one of frequency, timeslots, temporary flow identity, timing advance and uplink state flag.

5. The method according to any of claims 1 to 4, wherein the packet-switched mobile communication system is operated as a GPRS or EGPRS system.

6. The method according to claim 5, wherein the uplink temporary physical channel is a temporary block flow used by the mobile station and the network to support unidirectional transfer of upper layer information.

7. The method according to any of claims 1 to 6, wherein the network signals to the mobile station to use the uplink temporary physical channel with the parameters stored in the mobile station.

8. The method according to claim 7, wherein bit sequences used to signal to the mobile station are a supplementary polling bit or EGPRS supplementary polling bits.

9. The method according to claim 8, wherein the supplementary polling bit or EGPRS supplementary polling bits are set to ¹O'.

10. The method according to any of claims 8 or 9, wherein the bit sequences used to assign a temporary physical channel to the mobile station are relative reserved block period bits.

11. The method according to claim 10, wherein the relative reserved block period bits are set to indicate that the most recently, the second most recently or the third most recently stored parameters are used.

12. The method according to any of claims 1 to 11 , wherein the mobile station deletes the stored uplink temporary physical channel parameters upon returning to idle state.

13. A method in a packet-switched mobile communications system for establishing a downlink temporary physical channel between a network and a mobile station, the method comprising the steps of:

requiring by the network a downlink temporary physical channel;

assigning to the mobile station by the network the required downlink temporary physical channel;

storing parameters of the downlink temporary physical channel used by the mobile station; and

transmitting data to the mobile station by the network using the assigned downlink temporary physical channel with the stored parameters of a previously used downlink temporary physical channel.

14. The method according to claim 13 further comprising the step of releasing by the mobile station the downlink temporary physical channel.

15. The method according to any of claims 13 or 14 further comprising the step of acknowledging data by the mobile station after transmitting data by the network.

16. The method according to any of claims 13 to 15 wherein the parameters include at least one of frequency, timeslots, temporary flow identity, timing advance and uplink state flag.

17. The method according to any of claims 13 to 16 wherein the packet-switched mobile communication system is operated as a GPRS or EGPRS system.

18. The method according to claim 17, wherein the downlink temporary physical channel is a temporary block flow used by the network and the mobile station to support unidirectional transfer of upper layer information.

19. The method according to any of claims 13 to 18, wherein the network signals to the mobile station to use the downlink temporary physical channel with the parameters stored in the mobile station.

20. The method according to claim 19, wherein bit sequences used to signal to the mobile station are a supplementary polling bit or EGPRS supplementary polling bits.

21. The method according to claim 20, wherein the supplementary polling bit or EGPRS supplementary polling bits are set to ¹O'.

22. The method according to any of claims 20 or 21 , wherein the bit sequences used to assign a temporary physical channel to the mobile station are relative reserved block period bits.

23. The method according to claim 22, wherein the relative reserved block period bits are set to indicate that the most recently, the second most recently or the third most recently stored parameters are used.

24. The method according to any of claims 13 to 23, wherein the mobile station deletes the stored downlink temporary physical channel parameters upon returning to idle state.

25. A method in a packet-switched mobile communications system for establishing an uplink temporary physical channel between a mobile station and a network, the method comprising the following steps to be carried out by the mobile station:

requesting to assign an uplink temporary physical channel;

transmitting data to the network using an assigned uplink temporary physical channel with the stored parameters of a previously used uplink temporary physical channel.

26. The method according to claim 25 further comprising the step of releasing the uplink temporary physical channel.

27. The method according to any of claims 25 or 26, wherein the parameters include at least one of frequency, timeslots, temporary flow identity, timing advance and uplink state flag.

28. The method according to any of claims 25 to 27, wherein the packet-switched mobile communication system is operated as a GPRS or EGPRS system.

29. The method according to claim 28, wherein the uplink temporary physical channel is a temporary block flow used by the mobile station and the network to support unidirectional transfer of upper layer information.

30. The method according to any of claims 25 to 29, wherein bit sequences used to signal to the mobile station are a supplementary polling bit or EGPRS supplementary polling bits.

31. The method according to claim 30, wherein the supplementary polling bit or EGPRS supplementary polling bits are set to ¹O'.

32. The method according to any of claims 30 or 31 , wherein the bit sequences used to assign a temporary physical channel to the mobile station are relative reserved block period bits.

33. The method according to claim 32, wherein the relative reserved block period bits are set to indicate that the most recently, the second most recently or the third most recently stored parameters are used.

34. The method according to any of claims 25 to 33, wherein the mobile station deletes the stored uplink temporary physical channel parameters upon returning to idle state.

35. A method in a packet-switched mobile communications system for establishing an uplink temporary physical channel between a mobile station and a network, the method comprising the following steps to be carried out by the network:

receiving a request from the mobile station to assign an uplink temporary physical channel;

assigning to the mobile station the requested uplink temporary physical channel; and

receiving data from the mobile station using the assigned uplink temporary physical channel with the stored parameters of a previously used uplink temporary physical channel.

36. The method according to claim 35, further comprising the step of acknowledging data after transmitting data by the mobile station.

37. The method according to any of claims 35 or 36, wherein the parameters include at least one of frequency, timeslots, temporary flow identity, timing advance and uplink state flag.

38. The method according to any of claims 35 to 37, wherein the packet-switched mobile communication system is operated as a GPRS or EGPRS system.

39. The method according to claim 38, wherein the uplink temporary physical channel is a temporary block flow used by the mobile station and the network to support unidirectional transfer of upper layer information.

40. The method according to any of claims 35 to 39, wherein the network signals to the mobile station to use the uplink temporary physical channel with the parameters stored in the mobile station.

41. The method according to claim 40, wherein bit sequences used to signal to the mobile station are a supplementary polling bit or EGPRS supplementary polling bits.

42. The method according to claim 41 , wherein the supplementary polling bit or EGPRS supplementary polling bits are set to ¹O'.

43. The method according to any of claims 41 or 42, wherein the bit sequences used to assign a temporary physical channel to the mobile station are relative reserved block period bits.

44. The method according to claim 43, wherein the relative reserved block period bits are set to indicate that the most recently, the second most recently or the third most recently stored parameters are used.

45. The method according to any of claims 35 to 44, wherein the mobile station deletes the stored uplink temporary physical channel parameters upon returning to idle state.

46. A packet-switched mobile communications system adapted to establish an uplink temporary physical channel between a mobile station and a network, wherein:

the mobile station is adapted to request the network to assign an uplink temporary physical channel;

the network is adapted to assign to the mobile station the requested uplink temporary physical channel;

the mobile station is further adapted to store parameters of the uplink temporary physical channel used; and the mobile station is further adapted to transmit data to the network using the assigned uplink temporary physical channel with the stored parameters of a previously used uplink temporary physical channel.

47. The system according to claim 46, the mobile further being adapted to release the uplink temporary physical channel.

48. The system according to any of claims 46 or 47, the network further being adapted acknowledge data after transmitting data by the mobile station.

49. The system according to any of claims 46 to 48, wherein the parameters include at least one of frequency, timeslots, temporary flow identity, timing advance and uplink state flag.

50. The system according to any of claims 46 to 49, wherein the packet-switched mobile communication system is operated as a GPRS or EGPRS system.

51. The system according to claim 50, wherein the uplink temporary physical channel is a temporary block flow used by the mobile station and the network to support unidirectional transfer of upper layer information.

52. The system according to any of claims 46 to 51 , wherein the network is adapted to signal to the mobile station to use the uplink temporary physical channel with the parameters stored in the mobile station.

53. The system according to claim 52, wherein bit sequences used to signal to the mobile station are a supplementary polling bit or EGPRS supplementary polling bits.

54. The system according to claim 53, wherein the supplementary polling bit or EGPRS supplementary polling bits are set to O'.

55. The system according to any of claims 53 or 54, wherein the bit sequences used to assign a temporary physical channel to the mobile station are relative reserved block period bits.

56. The system according to claim 55, wherein the relative reserved block period bits are set to indicate that the most recently, the second most recently or the third most recently stored parameters are used.

57. The system according to any of claims 46 to 56, wherein the mobile station is adapted to delete the stored uplink temporary physical channel parameters upon returning to idle state.

58. A mobile station in a packet-switched mobile communications system adapted to establish an uplink temporary physical channel between the mobile station and a network, the mobile station comprising:

a request section adapted to request the network to assign an uplink temporary physical channel;

a storage section adapted to store parameters of the uplink temporary physical channel used; and

a transmitting section adapted to transmit data to the network using the assigned uplink temporary physical channel with the stored parameters of a previously used uplink temporary physical channel.

59. The mobile station according to claim 58 adapted to carry out the method steps according to claims 26 to 34.

60. A network in a packet-switched mobile communications system adapted to establish an uplink temporary physical channel between a mobile station and the network, the network comprising:

a receiving section adapted to receive a request from the mobile station to assign an uplink temporary physical channel;

an assigning section adapted to assign to the mobile station the requested uplink temporary physical channel; and

a receiver adapted to receive data from the mobile station using the assigned uplink temporary physical channel with the stored parameters of a previously used uplink temporary physical channel.

61. The network according to claim 60 adapted to carry out the method steps according to claims 36 to 45.

62. A method in a packet-switched mobile communications system for establishing a downlink temporary physical channel between a network and a mobile station, the method comprising the following steps to be carried out by the mobile station:

storing parameters of the downlink temporary physical channel used by the mobile station.

63. The method according to claim 62 further comprising the step of releasing by the mobile station the downlink temporary physical channel.

64. The method according to any of claims 62 or 63 further comprising the step of acknowledging data by the mobile station after transmitting data by the network.

65. The method according to any of claims 62 to 64 wherein the parameters include at least one of frequency, timeslots, temporary flow identity, timing advance and uplink state flag.

66. The method according to any of claims 62 to 65 wherein the packet-switched mobile communication system is operated as a GPRS or EGPRS system.

67. The method according to claim 66, wherein the downlink temporary physical channel is a temporary block flow used by the network and the mobile station to support unidirectional transfer of upper layer information.

68. The method according to any of claims 62 to 67, wherein bit sequences used to signal to the mobile station are a supplementary polling bit or EGPRS supplementary polling bits.

69. The method according to claim 68, wherein the supplementary polling bit or EGPRS supplementary polling bits are set to O'.

70. The method according to any of claims 68 or 69, wherein the bit sequences used to assign a temporary physical channel to the mobile station are relative reserved block period bits.

71. The method according to claim 70, wherein the relative reserved block period bits are set to indicate that the most recently, the second most recently or the third most recently stored parameters are used.

72. The method according to any of claims 62 to 71 , wherein the mobile station deletes the stored downlink temporary physical channel parameters upon returning to idle state.

73. A method in a packet-switched mobile communications system for establishing a downlink temporary physical channel between a network and a mobile station, the method comprising the following steps to be carried out by the network:

requiring a downlink temporary physical channel;

assigning to the mobile station the required downlink temporary physical channel;

transmitting data to the mobile station using the assigned downlink temporary physical channel with stored parameters of a previously used downlink temporary physical channel.

74. The method according to claim 73, wherein the parameters include at least one of frequency, timeslots, temporary flow identity, timing advance and uplink state flag.

75. The method according to any of claims 73 or 74, wherein the packet-switched mobile communication system is operated as a GPRS or EGPRS system.

76. The method according to claim 75, wherein the downlink temporary physical channel is a temporary block flow used by the network and the mobile station to support unidirectional transfer of upper layer information.

77. The method according to any of claims 73 to 76, wherein the network signals to the mobile station to use the downlink temporary physical channel with the parameters stored in the mobile station.

78. The method according to claim 77, wherein bit sequences used to signal to the mobile station are a supplementary polling bit or EGPRS supplementary polling bits.

79. The method according to claim 78, wherein the supplementary polling bit or EGPRS supplementary polling bits are set to O'.

80. The method according to any of claims 78 or 79, wherein the bit sequences used to assign a temporary physical channel to the mobile station are relative reserved block period bits.

81. The method according to claim 80, wherein the relative reserved block period bits are set to indicate that the most recently, the second most recently or the third most recently stored parameters are used.

82. A packet-switched mobile communications system for establishing a downlink temporary physical channel between a network and a mobile station, the system wherein:

the network is adapted to require a downlink temporary physical channel;

the network is adapted to assign to the mobile station the requested downlink temporary physical channel;

the mobile station is adapted to store parameters of the downlink temporary physical channel used; and

the network is further adapted to transmit data to the mobile station using the assigned downlink temporary physical channel with the stored parameters of a previously used downlink temporary physical channel.

83. The packet-switched mobile communications system according to claim 82 adapted to carry out the method steps according to claims 14 to 24.

84. A mobile station in a packet-switched mobile communications system for establishing a downlink temporary physical channel between a network and a mobile station, the mobile station comprising: a storage section adapted to store parameters of the downlink temporary physical channel.

85. The mobile station according to claim 84 adapted to carry out the method steps of claims 63 to 72.

86. A network in a packet-switched mobile communications system for establishing a downlink temporary physical channel between a network and a mobile station, the network comprising:

a requiring section adapted to require a downlink temporary physical channel;

an assigning section adapted to assign to the mobile station the required downlink temporary physical channel;

a transmitting section adapted to transmit data to the mobile station using the assigned downlink temporary physical channel with stored parameters of a previously used downlink temporary physical channel.

87. The network according to claim 86 adapted to carry out the method steps of claims 74 to 81.

88. A computer readable medium storing instructions that, when executed by a processor of a mobile station in a packet-switched mobile communications system cause the mobile station to establish an uplink temporary physical channel between the mobile station and a network, by:

requesting to assign an uplink temporary physical channel;

89. The computer readable medium according to claim 88, storing instructions that, when executed by a processor of a mobile station in a packet-switched mobile communications system cause the mobile station to establish an uplink temporary physical channel between the mobile station and a network, by carrying out the steps of the method according to any of claims 2 to 12.

90. A computer readable medium storing instructions that, when executed by a processor of a mobile station in a packet-switched mobile communications system cause the mobile station to establish a downlink temporary physical channel between a network and the mobile station, by:

assigning to the mobile station by the network the requested downlink temporary physical channel;

91. The computer readable medium according to claim 90, storing instructions that, when executed by a processor of a mobile station in a packet-switched mobile communications system cause the mobile station to establish an uplink temporary physical channel between the mobile station and a network, by carrying out the steps of the method according to any of claims 14 to 24.