Extended dynamic resource allocation for packet data transfer

0001These Invention relates to multiple access communication systems and relates in particular, the dynamic allocation in time division multiple access communication systems.

0002In Multiple access wireless systems such as the GSM system, communicates a number of mobile stations to a network. The allocation of physical communication channels for Use by the mobile stations is fixed. The GSM system is in The GSM System for Mobile Communications by M. Mouly and MB Pautet published Described with the ISBN reference 2-95071190-0-7.

0003since the introduction of packet data transmissions over TDMA systems (Time Division Multiple Access system) is at the Allocation of resources and in particular in the use of physical communication channels higher flexibility required.

0004For data transfers in GPRS systems (General Packet Radio System) provides a number uplink packet data channels, (Packet Data Channels (PDCH)) the physical communication link ready. The multiplexing is done in the context of 4.651 ms duration and each frame has eight consecutive 0.557 ms slots. The GPRS system is in 3GPP TS 43.064 v5.1.1. described.

0005the slots may for uplink or downlink communication are used. Uplink communication is a transmission the mobile station through the network to which the mobile station is connected, is to receive. The receipt of a transmission from the network by the mobile station is known as downlink.

0006Around the available to use bandwidth most efficiently, can access in response to changes in the Channel conditions, the traffic load, quality of service and the Subskriptionsklasse be allocated. Due to the continuously changing Ka nalbedingungen and traffic loads is a method for dynamically Allocation of the available channels to disposal.

0007the periods, in which the mobile station receives downlink or transmits uplink may be varied and the slots are allocated accordingly. The sequence of the Slots which are allocated for receiving and transmitting, the so-called multislot pattern is usually in the form of RXTY described. The allocated reception slots (R) have the number X and the allocated transmit slots (T) have the number Y. For GPRS operation A number of multislot classes from 1 up to and including 45 defined and the maximum uplink slot allocations (Tx) and the maximum downlink slot allocations (Rx) for each class certainly.

0008In a GPRS system, access to a shared Channel through an uplink status flag (USF), which on the downlink transmit any communication mobile station is controlled. In GPRS two allocation methods are defined, extending through the convention which uplink slots at reception a USFs available be made different. The present invention relates to a particular allocation method in which an equal "N" number of PDCHs (a PDCH illustrates a pair of uplink and downlink slots which each on a one-to-one basis correspond, represent) for the potential use provided by the MS. In the USF are available Uplink slots shown that an uplink channel shared-use certain mobile station actually can use. The USF is data accept the eight values ​​of V0-V7 can and enable, allocated that uplink resources between eight mobile stations can be, each of said mobile stations one of these eight values ​​"valid" recognizes as, ie, that exclusive Use of the equipment of this mobile station is allocated. A particular mobile station can be connected to a different USF value identify each of the mobile station allocated slots. In the Case of the extended dynamic allocation method, for example, the receipt of a valid USFs at the slot 2 of the existing framework, the actual availability for transfers of the slots 2, ..., N in the next TDMA frame or in Display Frame, where N is the number of allocated PDCHs is. Generally found for a valid USF was received at a transmission slot n, transmission in the next transmission frame to the transmission slots n to n + 1 and the following up to the allocated number of slots instead of (N). In the extended dynamic allocation method, as defined herein, these allocated slots are always successive following.

0009the Mobile station can not immediately receive from a state to a switch send state and vice versa. The time that this reconfiguring is allocated is known as the transfer time. It should also it for the mobile station, while it in the packet transfer mode is necessary to perform measurements of adjacent cells. the Mobile station must continuously all BCCH carrier (broadcast control channel carriers), as indicated by the BA (GPRS) list specified, and the BCCH carrier monitor the serving cell. At least one of the BCCH carrier is in each TDMA frame a received signal level measurement was made. The through the network guaranteed switching and measurement times for a mobile station are from the multi-slot class for which the mobile station conformity (3GPP TS 45.002v5.90, Annex B) claimed dependent.

0010the Measurements of neighboring cells before reconfiguring from receiving to sending or before reconfiguring Send made to receive.

0011A Mobile station with the present extended dynamic allocation method works, the uplink transmission needs in the Tx timeslot corresponding to the Rx timeslot in which the first valid USF is detected, begin. This means that a fixed ratio between the timing of the downlink allocation signaling and subsequent uplink transmission consists. Due to the physical limitations of single transceiver / receiver mobile stations are some desirable Multislot configurations are not available for use.

0012These restrictions reduce the availability of slots for the uplink transmission and thus reduce the flow of data and the flexibility of the reactions to changing Conditions. Therefore, there is a need to provide a method, with the use of these multi-slot configurations that currently not possible is for enhanced dynamic allocation can be made possible.

0013<patcit><text>EP 1248479</text></patcit> discloses a multiple access communication method open in a network on a downlink slot an uplink status flag sends to the mobile station that instructs a mobile station, an uplink transmission on a first uplink slot transmitted on a first uplink slot is to perform.

0014It An object of this invention, the limitations that advanced to the dynamic allocation function, with minimal impact on the existing to reduce regulation. This can by changing the fixed ratio between the timing of the downlink allocation signaling and subsequent uplink transmission for certain Classes of the mobile station can be achieved.

0015According to the invention a method for controlling uplink packet data transmission and a mobile station, in accordance using the enclosed in the claims outlined method works, provided.

0016in the Hereinafter, with reference to the accompanying drawings an embodiment described, in the drawings

0017<figref idrefs="S18">1</figref> the represents PPRS-TDMA frame structure, the numbering convention which, the for uses the uplink time slots (UL) and the downlink time slots is, shows

0018<figref idrefs="S18">2</figref> a Four slot steady state R1T4 allocation according to the prior art shows,

0019<figref idrefs="S18">3</figref> a Five-slot steady state allocation R1T5 which prohibits according to the prior art, shows,

0020<figref idrefs="S19">4</figref> a by the method of the invention enabled five-slot steady state R1T5 allocation shows

0021<figref idrefs="S19">5</figref> on shifted USF applied to a mobile station of class 7, with three uplink slots allocated shows

0022<figref idrefs="S19">6</figref> a 7 MS class with two assigned uplink slots shows

0023<figref idrefs="S20">7</figref> on Flowchart of implementing a displaced USFs in a Mobile station,

0024<figref idrefs="S21">8</figref> a transition from one uplink slot to five Uplink slots for a 34-MS-Class representsrepresents and

0025<figref idrefs="S21">9</figref> a transition four to five Uplink slots for representing a 34-MS class.

0026In this embodiment the invention is applied to a GPRS wireless network, in accordance with the standards applicable to multislot classes, operates. In the <figref idrefs="S18">1</figref> PPRS the TDMA frame structure is illustrated, the numbering convention used for the uplink time slots (UL) and the downlink time slots (DL) is used shows. It should be noted that in the Tx practice, because of the timing advance (TA) relative to Rx may be advanced, although this is not in the representation will be shown. Consequently, in practice, due to the timing advance the amount of time between the first Rx and first Tx of a frame by a fraction of a slot from the illustrated value of three slots can be reduced.

0027Two successive TDMA frames are the downlink slot (DL) and the uplink slot (UL) defined in separately. The slot positions within the first frame by becoming the numbers 0 through 7 appears, the transmit and receive slots to a size of three Slots are offset. This is done according to the convention, that the first transmit frame in a TDMA frame compared to the first receiving delayed by an offset of 3 may is (consequently a common Single slot GSM can be regarded as a special case, in which is only one transmit and receive slot used).

0028The remaining figures are consistent with the presentation in the <figref idrefs="S18">1</figref> agree However, the slot numbering has been removed for reasons of clarity. The shaded slots are those allocated to specific states were, and the inserted Arrows indicate the applicable measurement and switching intervals. the chopped slots indicate reception of a valid USFs and the time slots, where this USF is received at. As previously mentioned, permit by the requirement, measurement and Umschaltschlitze, restrictions imposed and the provision for these in 3GPP TS 45.002, Annex B, limits the dynamic allocation, as shown in Table 1. table 1 <img img-content="tb" img-format="tif" he="50" wi="164" file="00060001.tif" /><dl><dt>T_ta</dt><dd>is the time for the Mobile station is required to measure the signal level of the adjacent perform cell and to be ready to send.</dd><dt>T_tb</dt><dd>is the time for the Mobile station is required to be ready to send.</dd><dt>T_ra</dt><dd>is the time for the Mobile station is required to measure the signal level of the adjacent perform cell and to be ready to receive.</dd><dt>T_rb</dt><dd>is the time for the Mobile station is required to be ready to receive.</dd><dt>t₀</dt><dd>31 symbol periods Timing advance offset.</dd></dl>

0029It should be noted that the times T_ta and T_tb because of the timing advance to a fraction of a slot can be reduced.

0030In the <figref idrefs="S18">1</figref> be a single-permanent condition downlink allocation and four uplink slot allocations shown. The switching and measurement periods for this class are in the Table 1 as T_ra, T_rb and T_tb shown. T_ra and T_rb each have a slot and T_ta has two slots. These periods may for this Allocation be included if in the time slot 0 a valid USF Will be received.

0031If extends the allocation of uplink slots to five slots created limits how in the representation of the <figref idrefs="S18">3</figref>Which for a mobile station of class 34 with an allocation of one downlink slot and five uplink slots is shown.

0032the restriction occurs at a position indicated by "A" position one, because no time to switch from transmit to receive approved is. In the downlink slot 0 a valid USF has been received and the following two slots provide T_ta ready. According to the invention has the Mobile station in this embodiment, by the use of USF_TN0 ... USF_TN7 information elements in the packet uplink assignment and the packet timeslot reconfiguration message in the usual Fashion allocated uplink slots. The network sends however the USF for both the first and the second time slot assigned on the second assigned timeslot associated downlink PDCH.

0033by means of Example is a mobile station of class 34 with an assignment of five Uplink slots (TN0-TN4) as discussed above, considered in which the network instead of USF_TN0 on timeslot 1 sends timeslot 0th This arrangement is in the<figref idrefs="S19">4</figref> shown, can be seen that the area marked "B" and "C" slots each switching times T_ra and T_rb provide.

0034A Allocation by the network of four uplink slots to the mobile station is signaled by sending USF_TN1 on timeslot. 1 The characters of the two signals USF_TN0 and USF_TN1 have different and must have can be distinguished from the mobile station.

0035It is not necessary, additional add information elements, to indicate when to use the shifted USF mechanism is, as these in the timeslot allocations for the particular multislot class the mobile station can be implied. Therefore, no increase in the Signaling overhead required.

0036In the <figref idrefs="S19">5</figref> is another example of an allocation that is made possible by the implementation of a shifted USFs, shown. This application is a mobile station of class 7, the three uplink slots are allocated. The USF in the downlink slot containing the three uplink slots allocated by, indicates that the first available uplink slot instead of the usual Slot 1 of the uplink slot 0 is. This represents the T_tb- and T_raPeriods ready (as indicated by Table 1 required), as described in <figref idrefs="S19">5</figref> each appears at D and E. The allocation would be earlier, a sufficient period for T_ra been having, not available.

0037the in the <figref idrefs="S19">6</figref> illustrated two-slot-allocation returns to to normal operation, that is, the USF is not shifted. There are No physical restrictions in normal allocations for this two-slot arrangement of <figref idrefs="S19">6</figref> available and the standard USF in time slot 1 shares the uplink slots with the slot number 1 starting to.

0038alternative it may be expedient, a positive signaling the shift in the position of the uplink allocation apply, and an implementation of a shifted USFs in a mobile station operating extended dynamic allocation, is in the <figref idrefs="S20">7</figref> shown. It should noted be that the display (step <figref>2</figref>) in the <figref idrefs="S20">7</figref> explicit (Ie extra signaling) may be or implicitly (for certain multi-slot class configurations automatically may be). Referring to<figref idrefs="S20">7</figref> the mobile station receives (Step <figref>1</figref>) An allocation of uplink resources and the USFs of the network. If (step<figref>2</figref>) an ad, to use a shifted USF is detected then, for the first monitors USF, the second downlink slot (Step <figref>3</figref>), Otherwise the first downlink slot is monitored (Step <figref>4</figref>). In both cases the mobile station is initiated, if (step <figref>5</figref>) A valid USF was received uplink transmissions in the first uplink slot (step <figref>6</figref>). If (step<figref>5</figref>) no valid USF has been received, then (step <figref>7</figref>) Of the second downlink slot monitored for a second USF and if (step <figref>8</figref>) Is found that is valid, (step <figref>9</figref>) Uplink transmissions in the second Uplink slot initiated.

0039In the in the <figref idrefs="S18">2</figref> to <figref idrefs="S19">6</figref> illustrated Examples are the allocations in the steady state, so that the shown Allocations of frames remain to frame. The invention is not limited to the steady state allocations and can also be applied to the uplink resources so as to control that they change from one frame to another.

0040In the <figref idrefs="S21">8</figref> and <figref idrefs="S21">9</figref> are shown examples of transitions. Each of these figures represent successive frames, was However, each divided the presentation.

0041the <figref idrefs="S21">8</figref> provides the transition from one uplink slot allocation to five uplink slot allocations for a mobile station Class is 34th The first (top) two frames show steady state operation with a slot and the next (Bottom) two frames show the transitional frames. For this transition will the slot of the USF changed.

0042the <figref idrefs="S21">9</figref> provides the transition from four uplink slots to five Uplink slots for show a mobile station in Class 34. The first two frames the steady-state operation with four slots and the next two Frames show the transitional frames. For the transition USF arrangement remains constant, but the value of USFs is changed.

0043Around apply in GPRS systems, the invention, for example, a Table (Table 2) for a create mobile station of class 1 to enhanced dynamic Allocation to allow, using the following principles:

0044In the case of the extended dynamic allocation it is for the mobile station he wishes, physical until their " Send slot limit "to can, more specifically, the mobile station should be in a position to the maximum Number of slots in accordance with the restrictions its multi-slot class possible is to be transmitted, while it continues to receive the USF value on exactly one slot and decode, and the measurements carried out. If it is not possible, to define a multislot configuration of the mobile station using T_ra allows "up to to send its physical slot limit ", but through the use of T_ra possible would be, then to T_ra be used.

0045If it is not possible is a multi-slot configuration for extended dynamic to define allocation, which enables "until at the mobile station to send its physical slot limit ", but using the shifted USF mechanism possible would then to the shifted USF mechanism be used. In this Case T_ra used as first preference, However, if it is not possible , T is_ra used as a second preference.

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