Apparatus, and associated method, for communicating packet data in a radio communication system

Apparatus, and an associated method, by which to transmit packet data from a mobile station to network infrastructure of a TDMA, cellular communication system at an increased rate. The increased rate is provided while still operating the mobile station in half-duplex mode of operation. In one implementation, the mobile station is operable to effectuate triple-rate communication of packet data at a multi-rate defined in the GPRS-136 standard.

The present invention relates generally to the communication of packet data
 in a communication system, such as a TIA/EIA-136 cellular communication
 system which provides GPRS (General Packet Radio Service). More
 particularly, the present invention relates to apparatus, and an
 associated method, for communicating packet data between a mobile station
 and a radio base station of the network infrastructure of the
 communication system. A signaling scheme is provided which permits packet
 data to be transmitted at increased bit rates without requiring the mobile
 station to be operated in a full-duplex mode.
 BACKGROUND OF THE INVENTION
 Advancements in communication technologies have permitted the introduction
 of, and popularization of, new types of communication systems. As a result
 of such advancements, the rate of data transmission, and corresponding
 amount of data, permitted to be communicated in such communication
 systems, has increased.
 A radio communication system is representative of a type of communication
 system which has benefited from advancements in communication
 technologies. A radio communication system inherently increases
 communication mobility as communication channels defined in such a system
 are formed of radio channels and do not require wireline connections for
 their formation. A radio communication system, however, typically is
 bandwidth-limited. That is to say, regulatory bodies which allocate usage
 of the electromagnetic spectrum allocate only a limited amount of the
 electromagnetic spectrum for communications in a particular radio
 communication system. Because the spectrum allocation for use by a
 particular system is limited, communication capacity increase of a radio
 communication system is limited by such allocation. Increase of the
 communication capacity of the radio communication system, therefore, is
 typically only possible if the efficiency by which the allocated spectrum
 is used is increased.
 Digital communication techniques, for instance, provide a manner by which
 to increase the bandwidth efficiency of communications in a communication
 system. The use of digital communication techniques are particularly
 advantageously implemented in radio communication systems due to the
 particular need to efficiently utilize the spectrum allocated to such
 systems.
 A cellular communication system is exemplary of a radio communication
 system. Cellular communication systems make relatively efficient use of
 the spectrum allocated thereto. Signals generated during operation of the
 cellular communication system are of relatively low power levels. Because
 of the use of low-power signals, the same channels can be reused
 throughout a cellular communication system according to a cell reuse plan.
 Concurrent use of the same channels is permitted according to the cell
 reuse plan, thereby to effectuate different and concurrent communications
 on the same channels at different locations throughout the area
 encompassed by the cellular communication system.
 However, even with the relatively efficient utilization of the allocated
 spectrum, many cellular communication systems have been operated at their
 maximum capacities, particularly at certain times-of-day and within
 certain cells of the cellular communication system. Digital communication
 techniques have advantageously been utilized in cellular communication
 systems to increase the communication capacities of such systems.
 Increased communication capacity of both voice and non-voice information
 is generally provided as a result of use of such digital communication
 techniques.
 When information is digitized pursuant to a digital communication
 technique, the digitized information can be formatted into packets of data
 to be transmitted in packet form as discrete packets. When information is
 communicated in the form of packets of data, a dedicated channel need not
 necessarily be allocated for the transmission of the data. Instead, a
 channel can be shared, used by a plurality of mobile stations.
 GPRS (General Packet Radio Service) communications for a GSM (Global System
 for Mobile communications) is a packet data service which shall be
 available to subscribers of some GSM systems. Standard specifications
 promulgated by ETSI pertaining to GPRS communications define the
 communication protocols for communicating packet data in such a system.
 Both real-time and non-real-time communications can be effectuated
 utilizing packet data transmissions, such as those provided pursuant to
 GPRS. When real-time data is communicated, the manner, e.g., the rate in
 which the packets of data are communicated is required to be controlled to
 ensure that the packets of data are transmitted in a manner to permit
 their delivery in a timely manner at a destination.
 The standard relating to GPRS communications, for instance, sets forth a
 mode of operation and a signaling protocol between a mobile station and
 the network infrastructure pursuant to which the GPRS communications are
 effectuated. A mobile station, for instance, transmits packets of data
 during packet data communication operations according, and responsive, to
 such protocol. The ETSI GSM specifications define how the GPRS packets are
 transferred over the GSM radio interface between a mobile station and a
 base station. The ETSI GSM standards also define the GPRS network
 elements, interfaces between network elements, signaling procedures, and
 data transfer procedures between the mobile station and the network.
 The GPRS services will be provided also in TIA/EIA-136 mobile communication
 networks. The GPRS over TIA/EIA-136 has been named GPRS-136. GPRS-136 is
 being standardized in TIA. The GPRS-136 will differ from the GSM GPRS
 mainly in the radio interface part. It is necessary to define in the
 TIA/EIA-136 standards how the GPRS data packets will be transferred over
 the TIA/EIA-136 radio interface. This radio interface differs from the GSM
 radio interface in for instance bandwidth and frame structure. Most other
 aspects, except the radio interface, will be the same in GPRS-136 as in
 GSM GPRS. This means mainly that the ETSI GSM specifications will define
 the signaling procedures, data transfer procedures and the network
 elements and interfaces also in GPRS-136. From the user point of view many
 of the same services will be available as in GSM GPRS.
 The proposed standards pertaining to uplink transmissions, i.e., packet
 data communicated by a mobile station to the network infrastructure,
 contained in an existing GPRS-136 draft standard does not, however,
 provide for significant bit rate increases in uplink double and triple
 rate relative to full rate of operation. A significant problem which
 limits the bit rate increase in the double-rate and triple-rate modes of
 operation is due to the existing requirement that the same sub-channel be
 used for both the uplink transmission of packet data and downlink
 acknowledgment of receipt of each packet of data. Namely, a PCF
 sub-channel is utilized by the network infrastructure to transmit
 acknowledgment indications responsive to receipt, at the network
 infrastructure, of GPRS 136 MAC PDUs on the same sub-channel. Such PCF
 sub-channel is also utilized by the network infrastructure to allocate
 uplink time-slots to the mobile station to communicate the packets of data
 thereon.
 In other words, in the existing draft standard, a mobile station is
 required both to receive and to transmit upon the same sub-channel. But
 operation of the mobile station at a double or triple-rate of operation,
 would require full-duplex operation of the mobile station. Full-duplex
 operation would require more complex and costly implementation of the
 radio frequency circuitry of the mobile terminal.
 A manner by which to permit double- or triple-rate communication of the
 packet data while permitting the mobile station to operate in a
 half-duplex mode would therefore be advantageous.
 It is in light of this background information related to the communication
 of packet data that the significant improvements of the present invention
 have evolved.
 SUMMARY OF THE INVENTION
 The present invention, accordingly, advantageously provides apparatus, and
 an associated method, for communicating packet data at a desired rate.
 In one implementation, double- and triple-rate half-duplex modes of packet
 data transmission are provided for a GPRS-136 standard proposal which
 defines operational standards of packet data communications provided in
 the TIA/EIA-136 system.
 Improved bit rates of data transmission are provided through operation of
 an embodiment of the present invention without requiring a mobile station
 to be operated in a full-duplex mode. Bit transmission rates of packet
 data communicated by a mobile station to the network infrastructure is
 provided at the same level as triple-rate, full-duplex operation but
 without requiring full-duplex operation of the mobile station. The need
 otherwise to provide channels for implementing full-duplex operation of
 the mobile station is obviated.
 In one aspect of the present invention, when packet data is to be
 communicated by a mobile station to the network infrastructure of a
 cellular communication system, a request is first made by the mobile
 station to the network infrastructure for allocation to the mobile station
 for a fixed allocation of communication capacity to communicate an
 unbounded size transaction of packet data. The request also indicates the
 mobile station to be multi-rate half-duplex capable. Responsive to
 detection at the network infrastructure of the request, a determination is
 made whether to grant to the mobile station the communication resources to
 permit the communication of the packet data at a selected transmission
 rate. That is to say, the request for the fixed allocation is of a level
 to permit the communication of packet data at a selected multirate, such
 as a double-rate or a triple-rate. If a determination is made at the
 network infrastructure to grant to the mobile station communication
 capacity to effectuate the communication of the packet data at the
 selected rate, the network infrastructure grants to the mobile station
 communication resources by way of a downlink transmission to the mobile
 station. The grant is for a fixed allocation of a plurality of successive
 time-slots.
 In a specific implementation of the GPRS-136 draft standard for a
 TIA/EIA-136 cellular communication system, when the mobile station is to
 communicate packet data to the network infrastructure, the request is made
 as part of an uplink BEGIN PDU (Packet Data Unit). In particular, the
 request forms a portion of a BP (Bandwidth Preference) field of the PDU.
 The request includes an indication that the mobile station is capable of
 operation in a multirate, e.g., half-duplex, triple-, or full-rate mode,
 and further includes a request for an unbounded size transaction and usage
 of fixed allocation. Once the request is received at the network
 infrastructure, acknowledgment of the BEGIN request is returned to the
 mobile station by way of downlink ARQ status PDU (Protocol Data Unit). As
 part of the ARQ status PDU, the network infrastructure provides to the
 mobile station a grant of an allocation of time-slots within which the
 packets of data are to be communicated by the mobile station.
 In one implementation, the allocation commences from the first occurrence
 on the uplink of the sub-channel on which the mobile station receives the
 ARQ status PDU.
 The mobile station inserts CONTINUE PDUs in successive uplink time-slots to
 indicate to the network infrastructure that the transaction formed of the
 packet data is not yet complete. When a transaction is near completion by
 the mobile station, the mobile station sends a CONTINUE PDU with an END
 block indicating the BSN (Block Sequence Number) of the last data block.
 The base station acknowledges all CONTINUE PDUs by sending ARQ status
 PDU(s) after the end of the fixed allocation as a response to the mobile
 setting the PI (Poll Indication) bit in the last CONTINUE PDU.
 Thereby, when the mobile station is to be operated in a multi-rate, e.g.,
 double- or triple-rate mode of operation, by requesting allocation of the
 fixed allocation of time-slots to effectuate the communication at the
 selected bit rate, and subsequent grant of allocation thereto by the
 network infrastructure, half-duplex operation of the mobile station can
 commence. Packets of data are inserted into time-slots allocated thereto
 and the packets of data are transmitted by the mobile station to the
 network infrastructure. The desired bit transmission rate is provided
 without the need to operate the mobile station in a full-duplex mode which
 otherwise would require more complex and costly mobile terminal
 implementation. Also, because the grant is for a plurality of time-slots,
 separate grants need not be generated to grant the mobile station
 permission to transmit packet data during each time-slot. The base station
 acknowledges all CONTINUE PDUs with ARQ status PDUs at the end of the
 fixed allocation. This removes the necessity to use the PCF subchannel for
 individual acknowledgments.
 In these and other aspects, therefore, apparatus, and an associated method,
 is provided for facilitating communication of packet data upon time-slots
 defined upon a communication channel formed between a first communication
 station and a second communication station. A fixed allocation requester
 is coupled to receive indications of when the packet data is to be
 communicated to the second communication station. The fixed allocation
 requester indicates the first communication station to be fixed allocation
 capable and requests allocation of a fixed sequence of successive
 time-slots defined upon the communication channel. The successive
 time-slots of the fixed sequence of which the allocation is requested,
 defines a transmission rate at which the packets of data are to be
 communicated upon the communication channel to the second communication
 station. An allocation grant detector is coupled to receive indications of
 a grant of the fixed sequence of the successive time-slots received at the
 first communication station. The allocation granted the detector detects
 when the fixed sequence of the successive time-slots are allocated to the
 first communication station to communicate the packet data thereon. The
 grant encompasses a plurality of time-slots. A formatter is operable to
 detection by the allocation grant detector of the allocation of the fixed
 sequence of the successive time-slots to communicate the packet data
 thereon. The formatter formats the packet data within the time-slots of
 the fixed sequence of the successive time-slots allocated to the first
 communication station.
 A more complete appreciation of the present invention and the scope thereof
 can be obtained from the accompanying drawings which are briefly
 summarized below, the following detailed description of the presently
 preferred embodiments of the invention, and the appended claims.

DETAILED DESCRIPTION
 Turning first to FIG. 1, a radio communication system, shown generally at
 10, is operable at least to communicate packet data between a mobile
 station 12 and network infrastructure of the communication system. In the
 exemplary implementation shown in the Figure, the communication system 10
 comprises an EIA/TIA-136 cellular communication system which provides GPRS
 (General Packet Radio Service), such as that defined in a GPRS-136
 standard promulgated by the TIA, 136-330 draft standard. The elements in
 the Figure pertain to packet communications. While operation of an
 embodiment of the present invention shall be described with respect to
 such cellular communication system, in other implementations, other
 embodiments of the present invention are analogously operable in other
 communication systems to communicate packet data between a sending station
 and a receiving station.
 The network infrastructure of the cellular communication system 10 includes
 a plurality of spaced-apart radio base stations 14 positioned at spaced
 intervals throughout the geographical area encompassed by the
 communication system. The radio base stations 14 are fixed-site radio
 transceivers capable of multi-user communications. In the exemplary
 implementation shown in the Figure, groups of three radio base stations 14
 are co-located. Each radio base station 14 forms a sector cell 16. For
 purposes of illustration, the cells 16 are represented to be hexagonal in
 configuration.
 Groups of the radio base stations 14 are coupled to an SGSN (Serving GPRS
 Service Node) 20. The SGSN 20 is coupled to a TIA/EIA-41 MSC/VLR (Mobile
 Switching Center/Visitor Location Register) 22. And, in turn, the MSCO/VLR
 22 is coupled to a TIA/EIA-41 HLR (Home Location Register) 24.
 The SGSN 20 is further coupled to a GSM HLR 26 and to a GGSN (Gateway GPRS
 Service Node) 28. The GGSN is coupled to a PDN 30 (Packet Date Network) to
 which a correspondent entity 32 is also coupled.
 The SGSN 20 is further coupled to a GGSN 34 which is coupled to another
 PLMN (Public Land Mobile Network).
 During operation of the communication system, packet data is communicated
 between the mobile terminal 12 and a correspondent entity, such as the
 correspondent entity 32. Packet data communicated therebetween is routed
 over a radio link extending between the mobile station a base station 14
 through the nodes 20 and 28, and through the packet data network 30.
 Communication of packet data analogously can be effectuated between a
 mobile station 12 and another correspondent entity, such as a
 correspondent entity coupled to the PLMN 36.
 The aforementioned GPRS-136 standard for TIA/EIA-136 sets forth a radio air
 interface standard defining protocols of operation for communicating the
 packets of data from the mobile station 12 to the radio base station 14 to
 perform GPRS in the TIA/EIA-136 system. Such standard sets forth, amongst
 other things, signaling protocols by which the mobile station requests,
 and is granted, communication resources to effectuate the communication of
 packet data from the mobile station to the radio base station, thereafter
 to be routed therefrom.
 Existing proposals define the protocols by which the mobile station
 requests, and the network infrastructure grants, communication resources
 for the communication of the packets of data. A standard rate at which the
 packets are transmitted is defined in which packets of data communicated
 by the mobile station are transmitted on the same uplink subchannel that
 carries to the downlink PFC (Packet Channel Feedback) indicating
 acknowledgments and reservations to the mobile. Proposals have been set
 forth to increase the rate at which the packets of data are transmitted by
 the mobile station. For instance, double rate and triple rate modes of
 operation of the mobile station have been proposed. However, utilizing
 existing protocols, double- and triple-rate operation cannot be
 effectuated in conventional manner with a conventional signaling scheme
 without operating the mobile station in a full-duplex mode. An embodiment
 of the present invention provides a manner by which to permit the mobile
 station to transmit at multi-rates, e.g., the double or triple-rates,
 while operating the mobile station in a half-duplex mode.
 FIG. 2 illustrates the mobile station 12 and a portion of the network
 infrastructure, each operable pursuant to an embodiment of the present
 invention. The portion of the network infrastructure is here identified as
 a logical element, a FA (Fixed Allocation) manager 42. The logical element
 is located, e.g., at any of the elements shown in FIG. 1 to form the
 network infrastructure of the cellular communication system 10, or
 distributed amongst more than one element.
 The mobile station 12 is here shown to include a receive portion 44 and a
 transmit portion 46 operable to receive and to transmit radio signals,
 respectively. A data source 48 sources packet data which is transmitted by
 the transmitter portion 46. And, a data sink 52 is coupled to the receiver
 portion 44.
 The mobile station 12 further includes a controller 54 operable to control
 operation of the mobile station. The controller 54 is here shown to
 include a functional element forming a fixed allocation requester 56. The
 requester 56 is coupled to receive indications when packet data sourced by
 the data 48 is to be communicated by the mobile station. Responsive to
 such indications, the requester 56 causes generation of a request for
 transmission to the FA manager 42 for a fixed allocation of successive
 time-slots upon a reverse packet channel to effectuate transmission of
 packets of data at a selected transmission rate. The request includes an
 indication of multi-rate capability of the mobile station.
 A representative portion of a reverse paging channel 58 is also shown in
 the Figure. The fixed allocation requester requests the fixed allocation,
 in a BP field of an uplink BEGIN PDU, indicated as section 62 of the
 portion of the reverse channel 58.
 The FA manager 42 is here shown to include a functional element forming a
 fixed allocation request detector 64. The fixed allocation request
 detector detects the request for the fixed allocation of successive
 time-slots generated by the mobile station 12 and here transmitted in the
 BP field 62. Indications of detections made by the detector 64 are
 provided to a grantor 66.
 The grantor is operable responsive to detection by the detector 64 of the
 indications of the request contained in the field 62 of the paging channel
 58. The grantor 66 is operable first to acknowledge the BEGIN PDU detected
 by the detector 64 indicated by the status indication defined upon a
 forward paging channel 72. An ARQ status PDU (Packet Data Unit) 74 is
 defined upon the paging channel 72.
 The grantor 66 is further operable to selectively grant to the mobile
 station 12 a fixed allocation of a selected number of time-slots for the
 mobile station to communicate packet data on the reverse channel 58. If
 the grantor 66 determines not to grant to the mobile station such a fixed
 allocation, the grantor is operable to require the mobile station 12 to
 operate in conventional reserve access mode.
 The ARQ status PDU 74 includes a field that indicates the fixed allocation
 and the number of time-slots allocated by the grantor for the mobile
 station to communicate the packet data thereon. The allocation commences
 from the first occurrence of a corresponding uplink sub-channel on which
 the mobile station received the ARQ status PDU 74. Here, the fixed
 allocation is indicated by the line segment 76. That is to say, the
 time-slots on the reverse channel falling within the length of the line
 segment 76 are the time-slots of the fixed allocation to the mobile
 station. The PCF (packet channel feedback) sub-channel of the time-slot
 that contains the ARQ status indicates allocation of this sub-channel to
 the mobile station. During the fixed allocation, an SA field of the PCF on
 all downlink slots indicates allocation to the mobile station.
 The controller 54 of the mobile station 12 further includes a functional
 element forming an allocation grant detector 82 coupled to receive
 indications of the portion 74 of the forward channel 72 which contains the
 ARQ status PDU. And, the controller 54, further includes a functional
 element forming a formatter 84 operable responsive to detection by the
 allocation grant detector 82 of the grant of the fixed allocation of
 time-slots to the mobile station. The formatter 84 is operable to cause
 formatting within the time-slots of the fixed allocation of time-slots of
 the packet data for communication from the mobile station 12 to the
 network infrastructure.
 The formatter 84, pursuant to its formatting operations, also inserts
 CONTINUE PDUs in the successive uplink time-slots allocated pursuant to
 the grant. That is to say, in each of the time-slots of the reverse
 channel of the fixed allocation, indicated by the line segment 76, a
 CONTINUE PDU is inserted. Such CONTINUE PDUs, when received at the FA
 manager 42, indicate that the transaction, i.e., transmission of the
 packet data, is to continue and is not yet completed. In one
 implementation, the CONTINUE PDU includes a PI (packet indicator) bit. The
 PI bit is set in any selected CONTINUE PDU to initiate an ARQ status to be
 returned by the network infrastructure. Such operation permits recovery
 from a "stalled TX window" situation and also permits more efficient use
 of the packet channel than waiting for termination of the fixed allocation
 to take additional action. Setting the PI bit indicates a request to end
 fixed allocation. When the BS notices the PI bit, it sends an ARQ status
 to the mobile.
 As indicated at the time-slot location 86 of the portion 58 of the reverse
 channel shown in the Figure, the quota of time-slots granted to the mobile
 station finishes, and, in subsequent time-slots indicated by the
 time-slots 88 the FA manager schedules uplink time-slots to another mobile
 station.
 The time-slot indicated at the location 92 of the portion of the reverse
 channel 72 indicates the quota of time-slots granted to the mobile station
 12 within the allocation indicated by the line segment is complete, and
 the mobile station 12 stops transmitting packet data, and instead,
 commences receive operations. Subsequent to the time-slots 88, the FA
 manager sends another ARQ status format 2 PDU to the mobile station. This
 ARQ status includes a bit map within the field 92.
 If another fixed allocation is to be granted to the mobile station 12 by
 the grantor 66, the subsequent fixed allocation link forms a portion of
 the field 92 of the ARQ status format to PDU. Additional fixed allocations
 are necessitated if the transaction requires the allocation of additional
 time-slots to complete the transaction. Again, the grant issued by the
 network infrastructure is for a plurality of successive time-slots.
 At the time indicated at location 94, the allocation grant detector 78
 detects the ARQ status format 2 PDU. Responsive thereto, the formatter 84
 is caused to format additional packets of data into the time-slots
 allocated to the mobile station.
 FIG. 3 illustrates a sequence diagram, shown generally at 102,
 representative of the procedure by which the mobile station requests, and
 the FA manager 42 allocates, a fixed allocation of successive time-slots
 upon which the mobile station transmits packets of data to effectuate
 multi-rate, e.g., double- or triple-rate, operation of the mobile station.
 First, and as indicated by the sequence segment 104, the mobile station
 requests a fixed allocation of time-slots to effectuate an unbounded size
 transaction. In the aforementioned GPRS-136 system, such a request is
 contained in the BP field of an uplink BEGIN PDU indicating to the network
 infrastructure that the mobile station is multi-rate capable. The request
 also requests a fixed allocation of time-slots to effectuate a transaction
 of an unbounded size.
 Responsive to the request, the network infrastructure determines whether to
 grant the fixed allocation. When a grant of a fixed allocation of
 time-slots is to be made to the mobile station, the network infrastructure
 generates a downlink ARQ status 1 PDU, indicated by the sequence segment
 106. The PDU acknowledges to the mobile station receipt of the uplink PDU
 104 and also includes a field indicating the fixed allocation and the
 number of time-slots allocated to the mobile station.
 Then, and as indicated by the sequence segment 108, packets of data are
 transmitted by the mobile station. During each time-slot of the fixed
 allocation, if a subsequent time-slot is to be used to continue a
 transaction prior to its completion, a CONTINUE PDU is inserted into the
 time-slot. The CONTINUE PDU indicates to the network infrastructure of
 non-completion of a particular transaction. Successive fixed allocation
 requests and grants are utilized until a transaction is completed.
 FIG. 4 again illustrates the mobile station 12 and the FA manager 42, shown
 previously in FIG. 2. The various elements of the mobile station and of
 the FA manager correspond to commonly-referenced elements shown in FIG. 2.
 The operation of such elements is as above-described, and shall not be
 described again. FIG. 4 illustrates operation of the mobile station and
 the FA manager at the end of a fixed allocation transaction. Portions of
 the reverse paging channel and the forward channel 72 are again also shown
 in the Figure.
 Here, subsequent to a request for a fixed allocation by the mobile station,
 shown in FIGS. 2-3, the grantor 66 of the FA manager 42 grants to the
 mobile station 12 a fixed allocation of time-slots. Again, the grant is
 provided to the mobile station in the form of a downlink ARQ status format
 1 PDU 74 of the forward channel 72. Responsive thereto, the detector 78 of
 the mobile station detects the values contained in the field and causes
 formatter 84 to format the packets of data into the allocated time-slots
 to be communicated on the reverse packet channel during the allocated
 time-slots. And, formatter 84 again causes insertion of a CONTINUE PDU
 into the time-slots prior to completion of the transaction.
 When a determination is made at the mobile station that the transaction is
 approaching completion, such as at the last data block of the transaction,
 the formatter 84 inserts a CONTINUE PDU with an END BLOCK indicating the
 BSN of the last data block. The final data block of the transaction is
 transmitted by the mobile station on the reverse channel, the final data
 block having the BSN indicated in the END BLOCK thereof.
 The network infrastructure receives the last data block of the transaction
 transmitted thereto by the mobile station. Responsive thereto, a downlink
 ARQ status format 2 PDU with a bit map is inserted into the field 74 of
 the forward channel and transmitted to the mobile station.
 In the event that the fixed allocation time-slots allocated by the grantor
 66 to the mobile station ends prior to completion of communication by the
 mobile station of all of the data blocks, completion of the transaction
 can be effectuated in conventional manner. That is to say, single-rate
 transmission is used in which the mobile station is allocated uplink
 time-slots one at a time to effectuate completion of the transaction. In
 the event the transaction is completed prior to the end of the fixed
 allocation of time-slots, indicated by detection of the END BLOCK
 indicative of completion of the transaction, the GPRS manager is able to
 reschedule remaining portions of the fixed allocation of PDUs to another
 mobile station.
 FIG. 5 illustrates a sequence diagram, shown generally at 122, which
 illustrates operation of an embodiment of the present invention at the end
 of a fixed allocation transaction. When communication of a transaction
 formed of a plurality of packets of data from a mobile station to the
 network infrastructure is to be effectuated, requests are made by the
 mobile station for the allocation of successive time-slots upon which to
 communicate the packets of data. Subsequent to a request for the
 allocation of the time-slots, a grant is made by the network
 infrastructure, indicated by the sequence segment 124 which is
 communicated as a downlink ARQ status format 2 PDU. Detection is made at
 the mobile station of the PDU and uplink transmissions are generated,
 indicated by the sequence segment 126. An END portion of the transaction
 formed of the uplink transmissions of the packet data includes a CONTINUE
 PDU with an END BLOCK indicating the BSN of the final data block.
 Subsequent to communication of the last data block, the mobile station
 terminates its transmission and enters into a receive mode. Once the
 network infrastructure receives the last data block of the transaction, a
 downlink ARQ status format 2 PDU, indicated by the sequence segment 128,
 contains a bit map.
 Operation of an embodiment of the present invention thereby provides a
 manner by which to operate the mobile station at double- or
 triple-transmission-rates in a half-duplex mode. Merely by including a BP
 field value in an uplink BEGIN PDU, otherwise defined in a GPRS-136
 standard, defining a triple-rate half-duplex uplink, double- and
 triple-rates of transmission are achieved without requiring operation of
 the mobile station in a full-duplex mode.
 FIG. 6 illustrates a method flow diagram, shown generally at 132, listing
 the method steps of the method of operation of an embodiment of the
 present invention. The method facilitates communication of packet data
 upon time-slots defined upon a communication channel formed to extend
 between a first communication station and a second communication station.
 First, and as indicated by the block 134, a request is made by the first
 communication station for allocation of a fixed sequence of successive
 time-slots to communicate the packet data from the first communication
 station to the second communication station. The successive time-slots of
 the fixed sequence define a transmission rate at which the packets of data
 are to be communicated upon the communication channel.
 Then, and as indicated by the block 136, detection is made at the first
 communication station of when the request for the allocation of the fixed
 sequence is granted. And, as indicated by the 138, the packet data is
 formatted within the time-slots of the fixed sequence of the successive
 time-slots. Thereafter, the packets of data are transmitted from the first
 communication station to the second communication station.
 The previous descriptions are of preferred examples for implementing the
 invention and the scope of the invention should not necessarily be limited
 by this description. The scope of the present invention is defined by the
 following claims: