Extended dynamic resource allocation for packet data transfer

(54) Title: EXTENDED DYNAMIC RESOURCE ALLOCATION FOR DATA TRANSFER IN PACKAGE (30) Unionist Priority: I8 / 06/2003 gb 0314093.6 (71) Depositor (s): Matsushita Electric Industrial CO., LTD. (JP) (72) Inventor (s): Timothy Giles Beard, David Edward Cooper (74) Attorney: Dannemann, Siemsen, Bigler & Ipanema Moreira (86) International order: pct JP2004 / 002303 of 26/02/2004 (87) Publication International: wo 2004/114708 of 12/29/2004 (57) Summary: EXTENDED DYNAMIC RESOURCE ALLOCATION FOR PACKAGE DATA TRANSFER. The present invention relates to a method for controlling packet data transmissions on a TDMA wireless network to provide additional choices in allocating communication channels. The fixed ratio in the synchronization of the downlink allocation signal and the subsequent uplink transmission is changed for certain classes of mobile station to avoid physical restrictions. Examples of variations in USF signaling in GPRS are provided.

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Invention Patent Descriptive Report for EXTENDED DYNAMIC RESOURCE ALLOCATION FOR DATA TRANSFER IN PACKAGE.

Technical Field

The present invention relates to multiple access communication systems and in particular relates to dynamic resource allocation in time division multiple access systems.

Prior Art

In multiple wireless access systems such as GSM, a series of mobile stations communicate with a network. The allocation of physical communication channels for use by mobile stations is fixed. A description of the GSM system can be found in The GSM System for Mobile Communications by M. Mouly and Μ. B. Pautet, published in 1992 with the reference ISBN 2-9507190-0-7.

With the advent of packet data communications through Time Division Multiple Access (TDMA) systems, more flexibility is required in the allocation of resources and in particular in the use of physical communication channels. For packet data transmissions on General Packet Radio Systems (GPRS), a series of Packet Data Channels (PDCH) provide physical communication links. The time division is by frames lasting 4.615 ms, and each frame has eight consecutive 0.577 ms segments. A description of the GPRS system can be found at (3GPP TS 43.064 v5.1.1). The segments can be used for uplink or downlink communication. The uplink communication is a transmission from the mobile station for reception by the network with which it is connected. Reception by the mobile station of a transmission from the network is described as a downlink.

In order to make the most effective use of available bandwidth, access to channels can be allocated in response to changes in channel conditions, traffic loading, Quality of Service and subscription class. Due to channel conditions changing continuously and traffic loads, a method for dynamically allocating available channels is available.

The amounts of time that the mobile station receives from the downlink or transmits from the uplink can be varied and the segments allocated accordingly. The segment sequences allocated for reception and transmission, the so-called multi-segment pattern, is usually described in the form RXTY. The receiving segments (R) allocated being the number X and the transmission segments (T) allocated the number Y.

A series of classes with multiple segments, one up to 45, is defined for GPRS operation and the maximum uplink (Tx) and downlink (Rx) segment allocations are specified for each class.

In a GPRS system, access to a shared channel is controlled by means of an Uplink Condition Indicator (USF) transmitted on the downlink to each mobile station (MS) of communication. In GPRS, two allocation methods are defined, which differ in the convention about which uplink segments are made available at the reception of a USF. The present invention relates to a particular allocation method, in which an equal number N of PDCHs, a PDCH representing a pair of uplink and downlink segments corresponding to each other on a 1-1 basis, is allocated for potential use by MS. The uplink segments available for actual use by a particular mobile station sharing the uplink channel are indicated in the USF. The USF is a data item capable of obtaining 8 VO-V7 values, and allows uplink resources to be allocated within up to 8 furniture, where each furniture recognizes one of these 8 values ​​as 'valid', that is, conferring the use exclusive of the features for this furniture. A particular mobile station can recognize a different USF value in each of the segments assigned to this mobile station. In the case of the extended dynamic allocation method, for example, the receipt of a valid USF in segment 2 of the current frame will indicate the actual availability for transmission of transmission segments 2 ... N in the next TDMA frame or group of frames, where N is the number of PDCHs allocated. Generally, for a valid USF received in the receiving segment n, the transmission takes place in the next transmission frame in the transmission segments n, n + 1 and the following until the number of allocated segments (N). For the dynamic allocation method extended as presently defined, these allocated segments are always consecutive.

The mobile station is not able to instantly switch from a reception condition to a transmission condition or vice versa and the time allocated for these reconfigurations is known as the transmission reversal time. It is also necessary for the mobile station, during packet transfer mode, to perform measurements of adjacent cells. The mobile station must continuously monitor all holders of the Diffusion Control Channel (BCCH), as indicated by the BA list (GPRS) and the BCCH carrier of the service cell. A measurement sample of the received signal level is obtained in each TDMA frame, in at least one of the BCCH carriers. (3GPP TS 45.008v5 10.0). The transmission and measurement reversal times guaranteed by the network for a mobile station depend on the multi-segment class to which the mobile claims compliance. (3GPP TS 45.002v5.9.0 Annex B).

Adjacent cell measurements are obtained before reconfiguration from reception to transmission or before reconfiguration from transmission to reception.

A mobile station operating in extended dynamic allocation mode must begin uplink transmission in time segment Tx corresponding to time segment Rx in which the first valid USF is recognized. This means that there is a fixed relationship in the synchronization of the downlink allocation signal and the subsequent uplink transmission. Due to the physical limitations of mobile stations with a single transceiver, some desirable multi-segment configurations are not available for use.

These restrictions reduce the availability of segments for uplink transmissions, thereby reducing data flow and flexibility to respond to changing conditions. Therefore, there is a need to provide a method with which the use of these configurations with multiple segments is currently unavailable for Extended Dynamic Allocation is allowed.

Description of the Invention

It is an objective of this invention to reduce restrictions by affecting extended dynamic allocation with minimal effect on the existing order. This can be achieved by changing the fixed ratio in the synchronization of downlink allocation signaling and subsequent uplink transmission for certain classes of mobile station.

According to the invention, there is a method for controlling data transmissions in an uplink packet and a mobile station operating according to the method, as specified in the appended claims.

Brief Description of Drawings

Figure 1 illustrates the GPRS TDMA frame structure showing the numbering convention used for uplink (UL) and downlink (DL) time segments;

Figure 2 illustrates a steady state allocation with 4 R1T4 segments from the prior art;

Figure 3 illustrates a steady state allocation with 5 R1T5 segments prohibited in the prior art;

Figure 4 illustrates a steady state allocation with 5 R1T5 segments allowed by the method of the present invention;

Figure 5 illustrates a displaced USF applied to a class 7 MS with 3 uplink segments allocated;

Figure 6 illustrates a class 7 MS with 2 allocated uplink segments;

Figure 7 is a flow chart for the implementation of the USF located at a mobile station;

Figure 8 illustrates a transition from an uplink segment to five downlink segments for a class 34 MS; and

Figure 9 illustrates a transition from four to five uplink segments for a class 34 MS.

Best Way to Carry Out the Invention

In this modality, the invention is applied to a wireless GPRS network operating according to the standards applicable for classes with multiple segments.

In Figure 1, the GPRS TDMA frame structure is illustrated and shows the numbering convention used for uplink (Tx) and downlink (Rx) time segments. It should be noted that in practice, Tx can be advanced in relation to Rx due to the synchronization advance (TA), although this is not shown in the illustration. Thus, in practice, the amount of time between the first Rx and the first Tx of a frame can be reduced by a fraction of a segment from the illustrated value of 3 segments due to the synchronization advance.

Two successive TDMA frames are illustrated with downlink (DL) and uplink (UL) segments identified separately. The segment positions within the first frame are shown by numbers 0 to 7 with the transmit and receive segments offset by a margin of three segments. This is in line with the convention that the first transmission frame in a TDMA delays the first reception frame by an offset of 3 (thus, GSM with a single common segment can be considered as a particular case in which only segment 1 transmission and reception is used).

The remaining figures conform to the illustration in figure 1, but the segment numbering has been removed for extra objectivity. The shaded segments are allocated to the particular states and the arrow inserts indicate the applicable measurement and transmission reversal intervals. The hatched segments indicate the receipt of a valid USF and the time segment in which this USF is received. As mentioned above, restrictions are imposed due to the need to allow measurement and transmission reversal segments and the prescription for these in the dynamic allocation of limits of 3GPP TS 45.002 Annex B, as shown in Table 1.

Table 1

<td rowspan="2">Class with Multiple Segments</td><td colspan="3">Maximum number of segments</td><td colspan="4">Minimum number of segments</td>

<td>Rx</td><td>Tx</td><td>Sum</td><td>T_you</td><td>T_Also</td><td>T_frog</td><td>T_rb</td>

<td> 7</td><td> 3</td><td> 3</td><td> 4</td><td> 3</td><td> 1</td><td> 3</td><td> 1</td>

<td> 34</td><td> 5</td><td> 5</td><td> 6</td><td> 2</td><td> 1</td><td> 1</td><td> 1</td>

<td> 39</td><td> 5</td><td> 5</td><td> 6</td><td> 2</td><td> 1</td><td>1 + to</td><td> 1</td>

<td> 45</td><td> 6</td><td> 6</td><td> 7</td><td> 1</td><td> 1</td><td> 1</td><td>to</td>

T_OK is the time required for the MS to measure the signal level of the adjacent cell and prepare to transmit.

T_Also is the time required for the MS to prepare to transmit T_frog is the time required for the MS to measure the signal level of the adjacent cell and prepare to receive.

T_rb it is the time needed for MS to prepare to receive.

It should be noted that, in practice, the T times_you and T_Also can be reduced by a fraction of a segment due to the synchronization advance.

T_O is a synchronization advance offset of 31 symbol periods

With reference to figure 2, a single steady-state downlink and an allocation of 4 uplink segments to a class 34 mobile station are illustrated. The transmission and measurement reversal periods for this class are shown in Table 1 as Tra, Trb and Ttb, each having one segment and Tta having two segments. These periods can be accommodated for this allocation when a valid USF is received in time segment 0.

However, when the uplink segment allocation extends to five, a constraint arises, as shown in the illustration in figure 3, which is for a class 34 mobile station with a downlink allocation and five uplink segments .

The restriction occurs at the position indicated by Ά 'because no time is allowed for the traffic transfer process from transmission to reception (Trb). In the downlink time segment 0, a valid USF is received and the next two segments provide Tta. According to the invention, for this modality, the mobile has uplink segments designated in the usual way, through the use of Information Elements USF_TN0 ... USF_TN7 in the packet Uplink Designation and Time Segment Reconfiguration messages of Package. However, the network sends the USF to both the first and second time segments designated in the downlink PDCH associated with the second designated time segment.

Considering, for example, a class 34 MS with a designation of 5 uplink segments (TN0 - TN4) as discussed above where the network sends USF_TN0 in time segment 1 instead of that in time segment 0. This provision is illustrated in figure 4, where it can be seen that the segments marked with 'B' and 'C' provide the transmission reversal times Tra and Trb, respectively.

An allocation by the network of 4 uplink segments to the MS will be signaled by sending USF_TN1 in time segment 1. The characters of the two signals USF_TN0 and USF_TN1 must be different and must be distinguishable by the mobile station.

It is not necessary to add extra information elements to indicate when the USF Offset mechanism should be used, as this can be done implicitly in the time segment allocations for the particular multisegment class of the mobile station.

Therefore, no increase in signaling overhead would be required.

With reference to figure 5, another example of an allocation allowed by the implementation of a displaced USF is illustrated in figure 5. The application is a class 7 MS with three uplink segments allocated. The USF on the downlink segment 1 allocating the 3 uplink segments indicates that the first available uplink segment is the uplink segment 0 instead of the usual 1 segment. This provides the periods Ttb and Tra (as required by table 1) and as shown in figure 5 in D and E, respectively. The allocation would not have previously been available for the need for a sufficient period for Tra.

The allocation of 2 segments shown in figure 6 reverts to normal operation, that is, the USF is not displaced. There are no physical restrictions on normal allocations for this 2-segment arrangement in Figure 6 and the standard USF in time segment 1 allocates uplink segments starting with the uplink segment number 1.

Alternatively, it may be convenient to apply positive displacement signaling in the uplink allocation position and an implementation of a USF displaced in a mobile station operating the extended dynamic allocation, is illustrated in figure 7. It should be noted that the indication ( 2) in figure 7 it can be explicit (that is, extra signaling) or implicit (automatic for the particular multithreaded class configuration). With reference to figure 7, the mobile station receives in 1 a designation of uplink resources and USF's from the network. If at 2, an indication to use a displaced USF is detected, then, for the first USF, the second downlink segment is monitored (3) otherwise the first downlink segment is monitored (4). In both cases, when a valid USF has been received at 5 then uplink transmissions are initiated on the first uplink segment from the mobile station (6). When no valid USF has been received at 5, then the second downlink segment is monitored against a second USF at 7 and, if valid (8), then uplink transmissions are initiated at the second uplink segment ( 9).

In the examples illustrated in figures 2 to 6, the allocations are steady state so that the allocations shown are maintained from frame to frame. The invention is not restricted to steady-state allocations and can also be applied to control uplink resources that change from one frame to another.

Examples of transitions are illustrated in figures 8 and 9. Each of these figures represents four consecutive frames, but they have been divided for presentation.

Figure 8 illustrates the transition from an uplink segment allocation to the allocation of five uplink segments, for a Class 34 mobile. The first two frames (top) show the steady state operation with one segment and the next two frames (bottom) show the transition frames. For this transition, the location of the USF segment is changed.

Figure 9 illustrates the transition from four uplink segments to five uplink segments, for a Class 34 mobile. The first two frames show the steady state operation with four segments and the next two frames show the transition. For this transition, the location of the USF segment is constant but the value of the USF is changed.

In order to implement the invention in GPRS, for example, a table (Table 2) can be built for a Type 1 MS to allow extended dynamic allocation using the principles below:

In the case of extended dynamic allocation, it is desirable for the MS to be able to transmit up to its physical segment limit; specifically, the MS must be able to transmit the maximum number of possible segments according to the limitation of its class with multiple segments, while continuing to receive and decode the USF value in exactly one segment and making measurements. If it is not possible to define a configuration with multiple segments that allows MS to transmit up to its physical segment limit using T_frog, but if it were possible to use T_tó, then T_fan should be used.

If it is not possible to define a configuration with multiple 5 segments for extended dynamic allocation that allows MS to transmit up to its physical segment limit, but if it is possible to use the displaced USF mechanism, then the displaced USF should be used. In this case, T_frog will be used as the first preference, but if this is not possible, T_OK will be used as a second preference.

Table 2

<td>Way of access to middle</td><td>N^s of Segments</td><td>T_frog must be applied</td><td>T_you must be applied</td><td>Applicable multithreaded classes</td><td>Note vation</td>

<td rowspan="5">Uplink, Dynamic Ext.</td><td> 1-3</td><td>Yes</td><td> -</td><td> 1-12, 19-45</td><td></td>

<td> 4</td><td>Not</td><td>Yes</td><td> 33-34, 38-39, 43-45</td><td> 2</td>

<td> 5</td><td>Yes</td><td> -</td><td> 34, 39</td><td> 5</td>

<td> 5</td><td>Not</td><td>Yes</td><td> 44-45</td><td> 2,4</td>

<td> 6</td><td>Not</td><td>Yes</td><td> 45</td><td> 5</td>

<td rowspan="7">Link downward + uplink, Dynamic ext.</td><td>d + u = 2-4</td><td>Yes</td><td> -</td><td> 1-12, 19-45</td><td></td>

<td>d + u = 5, d&gt; 1</td><td>Yes</td><td> -</td><td> 8-12, 19-45</td><td></td>

<td>d = 1, u = 4</td><td>Not</td><td>Yes</td><td> 30-45</td><td> 2</td>

<td>d + u = 6, d&gt; 1</td><td>Yes</td><td></td><td> 30-45</td><td> 2,3</td>

<td>d = 1, u = 5</td><td>Yes</td><td></td><td> 34, 39</td><td> 5</td>

<td>d + u = 7, d&gt; 1</td><td>Not</td><td>Yes</td><td> 40-45</td><td> 2,4</td>

<td>d = 1, u = 6</td><td>Not</td><td>Yes</td><td> 45</td><td> 5</td>

Continuation

Note 1

Observation 2

Observation 3

Observation 4

Observation 5

Normal measurements are not possible (see 3GPP TS 45.008).

Normal BSIC decoding is not possible (see 3GPP TS 45.008).

TA offset required for classes with multiple segments 35-39.

TA offset required for classes with multiple segments 40-45.

Operation of the displaced USF must be applied (see 3GPP TS 44.060)