O
`
`United States Patent (19)
`Wilson et al.
`
`(11)
`45
`
`US0052991 99A
`5,299,199
`Patent Number:
`Date of Patent: Mar. 29, 1994
`
`(54 CHANNEL RE-ASSIGNMENT METHOD
`FOR TIME DIVISION MULTIPLE ACCESS
`(TDMA) TRUNKED SYSTEMS
`75) Inventors: Timothy J. Wilson, Schaumburg;
`Kenneth J. Crisler, Wheaton, both of
`ill.
`73 Assignee: Motorola, Inc., Schaumburg, Ill.
`(21) Appl. No.: 894,396
`22 Filed: .
`Jun. S. 1992
`a Yg
`51) Int. Cli................................................ H04J 3/16
`(52) U.S. C. ................................... 370/95.3; 370/85.7
`(58) Field of Search .................... 370/95.1, 95.3, 94.1,
`370/85.7, 69.1; 455/34.1, 34.2, 58.2, 33.2, 33.1,
`54.2; 379/63, 56, 60
`References Cited
`U.S. PATENT DOCUMENTS
`2, E. A.
`et
`seas a was 370/95.1
`3.
`y
`ynk, Jr. et al. .
`4,829,543 5/1989 Borth et al. .
`4,887,266 12/1989 Neve et al. ......................... 3095.1
`4,949,336 8/1990 Hamada et al. .................. 370/85.15
`5,159,702 10/1992 Aratake .............................. 455/54.2
`
`(56)
`
`5,161,154 ll/1992 Diaz et al. .......................... 370/85.7
`5,163,047 1 1/1992 Perdikaris et al. .
`... 370/94.1
`Primary Examiner-Douglas W. Olms
`Assistant Examiner-Ajit Patel
`Attorney, Agent, or Firm-James A. Coffing; Steven G.
`Parmelee
`ABSTRACT
`57
`A radio communication system controller embodies the
`present invention by providing extended use (306) of a
`communication resource (106) to a plurality of commu
`nication units. The inventive method includes the steps
`of assigning (402) a first communication resource to a
`first communication unit, and then temporarily config
`uring (406) the assigned communication resource as a
`reserved resource. The controller then receives (408),
`from a second communication unit, a request to transmit
`a second communication on the assigned communica
`tion resource. Lastly, the controller re-configures (412)
`the assigned communication resource to allow transmis
`SO of
`second communication on the assigned com
`munication resource.
`24 Claims, 3 Drawing Sheets
`
`CONTROLLER OPERATION
`
`
`
`ASSIGN CHANNEL/SLOT
`
`|- DISCONNECT
`RECEIVED
`
`CONFIGURE ASSIGNED
`SLOT AS RESERVED
`
`VALID
`REQUEST RECEIVE
`
`RECONFIGURE ASSIGNED
`SOT TO FACILITATE REQUEST
`
`
`
`42
`
`
`
`MEASURE
`TRANSISSION PARAMETERS
`
`410
`
`HANG TIVE
`EXPRED
`YES
`RELEASE CHANNEL/SLOT
`
`
`
`
`
`
`
`416
`
`
`
`
`
`
`
`
`
`ERICSSON v. UNILOC
`Ex. 1019 / Page 1 of 9
`
`

`

`U.S. Patent
`
`Mar. 29, 1994
`
`Sheet 1 of 3
`
`5,299,199
`
`100
`AV C. 7
`T (UPLINK)
`103
`R1234,23412341234,2341234
`
`f01
`106
`
`
`
`102
`
`(DOWNLINK )
`R3412341234.123
`41234123412
`
`104
`
`AVC. 2
`203
`
`205
`
`106
`202
`208
`206
`CONFIG
`TRANSMISSION2%
`-201->
`202
`CONFIG
`CODE
`
`204
`
`UNUSED
`
`301
`
`
`
`30
`
`(UPLINK)
`306
`306
`
`307 300 309 .
`
`2%%22%22
`
`FRAME
`
`FRAME 2
`
`FRAME 5
`
`FRAME 4
`FRAME 3
`FRAME 6
`(DOWNLINK)
`302
`s
`305
`305
`g
`t
`2%%%%%
`
`
`
`
`
`
`
`| FRAME
`
`FRAME 2 T FRAME 3 T FRAME 4
`
`FRAME 5
`
`ERICSSON v. UNILOC
`Ex. 1019 / Page 2 of 9
`
`

`

`U.S. Patent
`
`Mar. 29, 1994
`
`Sheet 2 of 3
`
`5,299,199
`
`RECONFIGURE ASSIGNED
`SLOT TO FACILITATE REQUEST
`
`412
`
`WEASURE
`TRANSWISSION PARAMETERS
`
`410
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`CONTROLLER OPERATION
`
`ASSIGN CHANNEL/SLOT
`
`DISCONNECT
`RECEIVED
`
`CONFIGURE ASSIGNED
`SLOT AS RESERVED
`
`WAID
`REQUEST RECEIVE
`
`HANG TIME
`EXPRED
`YES
`RELEASE CHANNEL/SLOT
`
`
`
`
`
`
`
`
`
`ERICSSON v. UNILOC
`Ex. 1019 / Page 3 of 9
`
`

`

`U.S. Patent
`
`Mar. 29, 1994
`
`Sheet 3 of 3
`
`5,299,199
`
`GROUP UNIT OPERATION
`
`A77 6.6
`500
`
`507
`
`YES
`
`C END O
`
`
`
`NO
`
`NO
`
`505
`
`509
`
`SEND REQUEST TO TRANSMIT
`
`
`
`ID FIELD
`
`UNIT ID
`
`DETERVINE PRESENT
`TRANSWISSION PARAWETERS
`
`
`
`
`
`TRANSIT DATA r
`
`
`
`SEND DISCONNECT
`
`ERICSSON v. UNILOC
`Ex. 1019 / Page 4 of 9
`
`

`

`10
`
`30
`
`1.
`
`CHANNEL REASSIGNMENT METHOD FOR
`TME DIVISION MULTIPLE ACCESS (TDMA)
`TRUNKED SYSTEMS
`FIELD OF THE INVENTION
`The invention relates, in general, to radio communi
`cation systems, and in particular, to communication
`systems which employ a time division multiple access
`(TDMA) signalling protocol.
`BACKGROUND OF THE INVENTION
`Trunked radio frequency (RF) communication sys
`tems are well known in the art. In such systems, a plu
`rality of subscribers (e.g., mobiles, portables, consoles)
`15
`share a limited number of communication resources,
`e.g., channels. In particular, channels are typically as
`signed to requesting subscribers by a communication
`resource controller, which request and assignment are
`exchanged via a common control channel. The control
`20
`ler might assign a channel to an individual subscriber
`for a single transmission such that, at the end of the
`subscriber's transmission, the channel is re-assigned to
`another subscriber (i.e., so-called transmission trunk
`ing).
`25
`In the alternative, the controller might assign a chan
`nel to a group of subscribers for engaging in a conversa
`tion, and keep the channel assignment active until com
`pletion of, or a substantial pause in, the conversation.
`That is, the assigned channel is not made available for
`re-assignment until the end of the conversation is antici
`pated. A conversation may include multiple transmis
`sions from multiple subscribers and is referred to in the
`art as a message. Accordingly, this form of channel
`assignment is referred to as message trunking.
`35
`Subscribers attempting to engage in a conversation
`on a transmission trunked system are required to exe
`cute channel assignment request procedures for each
`transmission. Such procedures may result in significant
`transmission delay, particularly if an idle channel is not
`available at the time of the request. Message trunking
`eliminates the channel assignments within a conversa
`tion. Hence, message trunking presents benefits to the
`communication system users by allowing conversations
`to proceed in a more efficient and natural manner.
`45
`Prior art systems have attempted to offer message
`trunked services by appending a time delay, known as
`the "hang-time', to the end of each subscriber transmis
`sion. In these systems, the controller extends the assign
`ment (i.e., leaves it open for another subscriber belong
`50
`ing to the group who wishes to transmit) for a predeter
`mined period, or so-called hang-time. If no new trans
`mission is begun by the completion of the hang-time, the
`system controller terminates the channel assignment. As
`long as the time intervals between successive transmis
`55
`sions are less than the hang-time, message trunking is
`effectuated.
`During the course of a conversation, the communica
`tion controller typically receives transmissions from
`multiple subscribers. Each transmission may exhibit
`substantially different transmission characteristics, e.g.,
`propagation delay, power level, etc. These differences
`are at least partially due to the subscribers being located
`at substantially different distances from the communica
`tions controller. Today's message trunked communica
`65
`tion, e.g., frequency division multiplex (FDM) systems,
`simply accept each new transmission, and its associated
`transmission characteristics. Accordingly, the prior art
`
`5,299,199
`2
`method for accomplishing message trunking works well
`only for systems which are relatively robust with re
`spect to differences in transmission characteristics be
`tween multiple subscribers. A new method is required
`for systems which are more sensitive to differences in
`subscriber transmission characteristics.
`Communication systems employing time division
`multiple access (TDMA) signalling are well known.
`These systems divide an RF resource into a series of
`recurring time frames which are further divided into
`time-slots, as shown in FIG. 1. Time-slots 103, occur
`ring periodically in time frames 101, constitute the com
`munication channels of interest. As earlier described,
`the controller assigns a channel (i.e., time-slot) to a
`group of subscribers to enable a conversation among
`subscribers belonging to the group. That is, group mem
`bers communicate (i.e., transmit and receive) informa
`tion among themselves using the assigned time-slot,
`Unlike FDM systems, however, the timing of each
`subscriber transmission in a TDMA system must be
`strictly controlled to avoid interference among sub
`scribers transmitting on adjacent time-slots. In particu
`lar, even slight differences in transmission parameters,
`e.g., propagation delay, power level, cause an undesir
`able level of inter-slot interference.
`Many known systems control subscriber timing by
`enabling the controller to measure the arrival time of
`the received request on the control channel, and adjust
`ing the timing prior to the first transmission on the
`assigned channel. However, this measurement is only
`applicable to the subscriber submitting the initial re
`quest for a channel assignment. Subsequent transmis
`sions from other group members (i.e., which demon
`strate substantial differences in transmission timing from
`the initiating subscriber) can cause interference with the
`time-slots adjacent to the assigned time-slot. Similarly,
`excessive power levels of uplink transmissions may
`cause interference among adjacent time-slots, resulting
`in performance degradation. Control of transmission
`power levels from the initiating subscriber, therefore,
`would help to enhance system performance.
`Accordingly, there exists a need for a radio communi
`cation system which is able to maintain efficient usage
`of available communication resources, while limiting
`undesirable interference among those resources. In par
`ticular, a TDMA system which provides message
`trunking for group calls, would be an improvement
`over the prior art. That is, by reserving an assigned
`time-slot for the group members, and updating transmis
`sion parameters for each transmission, a TDMA radio
`system would not be constrained by foregoing limita
`tions of today's systems.
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 shows a simplified graphical representation of
`an uplink data frame sequence and a downlink data
`frame sequence, as is well known in the art.
`FIG. 2 shows a simplified graphical representation of
`a downlink slot, in accordance with the present inven
`tion.
`FIG.3 shows a simplified graphical representation of
`an uplink data stream and a downlink data stream, in
`accordance with the present invention.
`FIG. 4 shows a simplified flow diagram depicting the
`operation of a radio communication system controller,
`in accordance with the present invention.
`
`ERICSSON v. UNILOC
`Ex. 1019 / Page 5 of 9
`
`

`

`10
`
`5,299,199
`3
`4.
`FIG. 5 shows a simplified flow diagram depicting the
`user ID field 205 identifies the transmitting unit whose
`operation of a radio communication group unit, in ac
`right it is to now transmit into the assigned uplink slot
`cordance with the present invention.
`301. Slot descriptor field 201 also serves to convey the
`pertinent transmission parameters for the transmitting
`DETAILED DESCRIPTION OF A PREFERRED
`unit. In particular, transmission parameter field 206,
`EMBODIMENT
`which may be either a time advance value and/or a
`In a preferred embodiment of the invention, the com
`power level value as later described, is use to ensure
`munications resource takes the form of a particular set
`that the uplink transmission does not interfere with
`of slots on a time-division multiplexed (TDM) radio
`adjacent channels (i.e., time-slots).
`channel. The structure of the TDM radio channel is
`In a preferred embodiment, a time advance value is
`shown in FIG. 1. In particular, uplink 100 (i.e., trans
`written to transmission parameter field 206, and is used
`mitted from the subscriber to the central controller) and
`to convey to the transmitting unit an amount of time it
`downlink 102 (i.e., transmitted from the central con
`must advance, or delay, each of its uplink transmissions.
`troller to the subscriber) signals are transmitted on two
`This parameter is necessary to ensure that the transmis
`frequencies of a particular frequency pair. Uplink 100 is
`sions arrive at the controller at the proper time despite
`15
`divided into time-slots 103, and a particular number of
`the effects of propagation delay in the radio channel.
`slots are grouped together into frames 101 (e.g., four
`The time advance value is based on a measurement
`made by the controller on the request-to-transmit signal
`slots in each frame, as shown in FIG. 1) and indicated
`by the numbering of the time-slots. The number of com
`received from a unit wishing to transmit on the next
`munications resources available on the TDM radio
`available time-slot. Similarly, a power control value
`20
`channel is equal to the number of time-slots in each
`instructs the transmitting unit as to the correct power
`frame. Similar to uplink 100, downlink 102 is divided
`level to use on the uplink transmission, such that the
`into time-slots 106, and slots are grouped together into
`transmissions arrive at the controller with sufficient, but
`frames 104. In general, the uplink 100 and downlink 102
`not excessive, power to avoid undesired interference. In
`signals are partitioned in like manner (i.e., same number
`a preferred embodiment, it is the time advance value
`25
`of time-slots per frame).
`which is conveyed to the transmitting unit, but an em
`FIG. 2 shows a more detailed view of the information
`bodiment which either also, or instead, conveys the
`contained in a particular downlink slot 106 as it might
`power control value is also contemplated by the present
`appear in two configurations. Each downlink slot 106
`invention. Also, it should be noted that a communica
`contains a slot descriptor block 201. The slot descriptor
`tion unit which is able to detect its own transmission
`block includes a configuration code field 202, which
`parameter (e.g., time advance value, power control
`field indicates a present configuration of the slot (i.e.,
`value) is contemplated by the present invention.
`user traffic, reserved, or unassigned configuration).
`In a preferred embodiment, when the transmitting
`Configuration 203 shows downlink slot 106 as it might
`unit completes the data transmission (e.g., voice data), it
`be configured for user traffic, while configuration 204
`transmits a disconnect signal on a subsequent uplink
`35
`shows the same downlink slot as it might be configured
`time-slot (e.g., uplink slot 304). It should be noted that
`in both the reserved and unassigned modes, as later
`the disconnect signal could be replaced with any prede
`described.
`termined indicia, provided the controller was config
`In user traffic configuration (i.e., configuration 203),
`ured to recognize it. The controller then responds to the
`slot descriptor 201 contains a user identifier (ID) 205,
`disconnect signal by re-configuring the assigned slot to
`transmission parametric data field 206, and user data
`create a reserved time-slot. The controller indicates this
`field 208. In the reserved and unassigned configurations
`to members of the communications group by setting the
`(i.e., configuration 204), slot descriptor 201 contains
`configuration code (i.e., field 202) in the downlink slot
`only the appropriate configuration code (e.g., "001" for
`to "reserved', as depicted in downlink time-slots 305.
`reserved, and "000' for unassigned), while the remain
`The slot is thereafter available, at least for a predeter
`45
`der of the time-slot is unused. In a preferred embodi
`mined time as later described, to group members wish
`ment, the radio system controller modifies slot descrip
`ing to participate in the conversation (in a preferred
`tor 201 in downlink slot 106 to control the use of the
`embodiment, this includes the member who just com
`time-slot as a communications resource, as shown by
`pleted a transmission). Until a group member transmits
`way of example using FIG. 3.
`such a request, the assigned slot is empty, as depicted in
`50
`Referring to FIG. 3, there is shown an series of uplink
`uplink time-slots 306.
`frames 300, and a corresponding series of downlink
`Uplink time-slot 307 depicts a request-to-transmit
`frames 302. In a particular instance, the first slot of each
`signal being transmitted by a requesting group unit. The
`frame is assigned to a particular communications group
`request-to-transmit contains a requestor identification,
`for use in participating in a conversation. For example,
`which allows the controller to determine which unit is
`55
`a first member of the group might be transmitting user
`making the request. (It should be noted since the re
`data (301) into the assigned uplink slot, which is enabled
`questing unit does not yet have the required information
`by downlink slots being set to user traffic configuration
`regarding propagation delay for its transmissions, the
`(303). It should be noted that user data also appears on
`duration of the request to transmit signal, is preferably
`the assigned downlink slot, as previously described
`slightly shorter than the duration of the uplink slot. This
`using FIG.2 (i.e., field 208). Downlink user data signals
`insures that the transmission does not interfere with the
`are subsequently received by the transmitting unit as
`neighboring slots in spite of the unknown propagation
`well as the remaining units of the communications
`delay.)
`group.
`As previously discussed, the controller might derive
`Prior to allowing a transmission, the controller up
`several transmission parameters from the request-to
`65
`dates the slot descriptor field (i.e., 201 shown in FIG. 2)
`transmit sent by the requesting unit. The controller
`of the downlink slot with information that is required
`might measure the temporal position of the transmis
`for proper operation of the transmitting unit. That is,
`sion, from which it determines a propagation delay
`
`30
`
`ERICSSON v. UNILOC
`Ex. 1019 / Page 6 of 9
`
`

`

`20
`
`5,299,199
`5
`6
`characteristic of the requesting unit, and derive from
`Having been assigned to the communication resource
`that measurement a time advance value which applies
`(i.e., slot), the unit decodes (501) the downlink slot
`to the requesting unit. Further, it might measure the
`information. The unit continues to evaluate the configu
`received power level of the transmission, from which it
`ration code of the downlink slot until the configuration
`derives a power control value which applies to the
`is no longer "user traffic". That is, so long as the config
`requesting unit. In either case, or in the case where the
`uration code remains "user traffic', the unit will con
`requesting unit might utilize both parameters to opti
`tinue to decode (501) the downlink slot information.
`mize its transmissions, the transmission parameters are
`Having determined (503) that the slot no longer holds
`conveyed to the requesting unit on a subsequent down
`traffic, the unit determines (505) whether or not the slot
`link slot.
`has been configured as "unassigned". If so, the unit
`In response to a valid request-to-transmit, the con
`reverts to monitoring (507) the control resource (e.g.,
`troller re-configures the assigned slot by setting the slot
`another slot) and the routine is exited.
`descriptor in the downlink slot to a user traffic configu
`If it is determined (505) that the configuration code is
`ration code. The controller updates the fields of the slot
`not "unassigned' (i.e., it must be "reserved"), the unit
`descriptor with the correct requestor ID, and transmis
`determines (509) whether or not the user has asserted
`sion parameters(s). This information is conveyed to the
`push-to-talk (PTT), which would indicate that the
`requesting unit via the slot descriptor fields of the
`group unit wishes to become the transmitting unit. If
`downlink slots 308, allowing the requesting unit to com
`PTT has not been asserted, the unit continues to decode
`mence its user data transmission in subsequent time-slot
`(501) slot information, as before. If PTT has been as
`309. This sequence completes the preferred cycle, in
`serted, the unit tries to acquire the right to transmit by
`accordance with the present invention.
`sending (511) a request-to-transmit on the uplink slot.
`FIG. 4 shows a flow diagram 400 depicting the oper
`The unit then continuously checks (513) for the config
`ation of the radio communication system controller, in a
`uration code to change to "traffic', indicating that a
`preferred embodiment of the invention. The controller
`valid request-to-transmit was received by the control
`assigns (402) a TDM time-slot to a group of communi
`ler. When the configuration code changes to "traffic',
`25
`cation units, thereby establishing one member of the
`the unit checks (515) the user ID field in the slot de
`group as the transmitting unit. The controller then waits
`scriptor to see if it matches its own ID. If not, i.e., an
`(404) until a disconnect is received from the transmit
`other unit has become the transmitting unit, the unit
`ting unit, indicating completion of its transmission.
`returns to decode (501) slot information. If the user ID
`When a disconnect is received, the controller config
`field matches that of the unit, the unit determines (517)
`30
`ures (406) the assigned slot as a reserved slot, and waits
`its present transmission parameter(s) (i.e., by reading the
`(408), for a predetermined time as later described, to
`appropriate field in the slot descriptor block to obtain its
`receive a valid request-to-transmit from a second, or the
`time advance and/or power control values). Once it has
`same, member of the group.
`been determined that the unit has the right to transmit
`After a valid request is received, the controller mea
`on the assigned/reserved slot, the unit transmits (519)
`35
`sures (410) the appropriate transmission parameters
`user data into the uplink slot, while continuously check
`(e.g., propagation delay characteristic, power level),
`ing (521) for the PTT to be released. Upon release of the
`from which it calculates a time advance and/or power
`PTT, the unit sends (523) a disconnect signal on the
`control value. The controller then re-configures (412)
`uplink slot, and returns to decoding (501) downlink slot
`the assigned slot to facilitate the request. That is, the
`information.
`40
`controller changes the configuration code field to "us
`In the foregoing manner, members of a communica
`er-traffic', and updates the user id and transmission
`tion group may exchange messages, via a single time
`parameter fields of the downlink slot (e.g., slot 203 of
`slot, until a conversation has been completed. That is,
`FIG. 2) to reflect the appropriate data for the request
`by reserving the assigned time-slot for a predetermined
`ing unit. These parameters are conveyed to all group
`time (i.e., hang-time), the radio communication system
`45
`members, allowing the requesting unit to respond, as
`can make efficient use of the limited communication
`later described using FIG. 5, by transmitting a message
`resources available to users. Further, the TDMA sys
`to the rest of the group. The controller then returns;
`tem controller is able to maintain high volumes of group
`waiting (404) to receive a disconnect from the new
`calls, using the aforementioned analogy to message
`transmitting unit.
`trunking, while sustaining superior levels of perfor
`Returning to decision 408, if no request-to-transmit is
`mance through reduced interference among adjacent
`received, the controller determines (414) whether or
`time-slots.
`not a so-called "hang-time” has expired. The hang-time
`What is claimed is:
`is simply a predetermined amount of time during which
`1. In a radio communication system controller, a
`a group member may respond, via the reserved slot,
`method of providing extended use of a communication
`55
`before the slot is released to other system users. In a
`resource to a plurality of communication units, the
`preferred embodiment, the hang-time ranges from one
`method comprising the steps of:
`to 10 seconds, but other durations might be suitable,
`A) assigning a first communication resource to a first
`depending on system loading and typical message dura
`of the plurality of communication units to produce
`tions. If no request is received before the hang-time
`an assigned communication resource;
`60
`expires, the controller releases (416) the assigned/-
`B) temporarily reserving, in response to a predeter
`reserved slot by changing the configuration code to
`mined indicia received from the first communica
`"unassigned', as depicted in slot 204 of FIG. 2.
`tion unit during a first communication, the assigned
`FIG. 5 shows a flow diagram depicting the operation
`communication resource such that a reserved com
`of a communication group unit, in accordance with the
`munication resource is produced;
`present invention. (FIG. 5 depicts the operation of a
`C) receiving on the reserved communication re
`communication unit which is initially not the transmit
`source, from a second of the plurality of communi
`ting unit, but rather a group member monitoring a call.)
`cation units, a request to transmit a second commu
`
`O
`
`65
`
`ERICSSON v. UNILOC
`Ex. 1019 / Page 7 of 9
`
`

`

`5
`
`10
`
`15
`
`5,299,199
`7
`8
`nication on the assigned communication resource;
`E) determining a time advance value for the commu
`nication unit based on a present transmission pa
`and
`D) re-configuring, in response to the request, the
`rameter for the communication unit.
`assigned communication resource to allow trans
`12. The method of claim 11, wherein step E com
`prises the step of:
`mission of the second communication on the as
`E1) receiving the time advance value from the radio
`signed communication resource.
`2. The method of claim 1, further comprising the step
`controller.
`13. The method of claim 11, wherein step E com
`of:
`prises the steps of:
`E) measuring a transmission parameter for the second
`E1) receiving the present transmission parameter
`communication unit.
`3. The method of claim 2, wherein step E comprises
`from the radio controller; and
`the step of:
`E2) calculating the time advance value based on the
`received present transmission parameter.
`E1) determining a time advance value based on a
`14. The method of claim 10, further comprising the
`propagation delay characteristic of the request
`step of:
`received from the second communication unit.
`E) determining a power control value for the commu
`4. The method of claim 3, wherein step D comprises
`nication unit based on a present transmission pa
`the step of:
`D1) updating the assigned communication resource
`rameter for the communication unit.
`15. The method of claim 14, wherein step E com
`such that the time advance value is conveyed to the
`20
`prises the step of:
`second communication unit.
`E1) receiving the power control from the radio con
`5. The method of claim 2, wherein step E comprises
`the step of:
`troller.
`16. The method of claim 14, wherein step E com
`E1) determining a power control value of the request
`prises the steps of:
`received from the second communication unit.
`25
`E1) receiving the present transmission parameter
`6. The method of claim 5, wherein step D comprises
`from the radio controller; and
`the step of:
`E2) calculating the power control value based on the
`D1) updating the assigned communication resource
`received present transmission parameter.
`such that the power control value is conveyed to
`17. In a time-division multiple-access (TDMA) radio
`the second communication unit.
`communication system, a method, for use in a radio
`7. The method of claim 2, wherein step D comprises
`system controller, of providing extended use of one of a
`the step of:
`plurality of time-slots for communication among a plu
`D1) updating the assigned communication resource
`rality of communication units belonging to a communi
`such that the measured transmission parameter is
`cation group, each of the time-slots having data fields
`conveyed to the second communication unit.
`for conveying information, the method comprising the
`8. The method of claim 1, wherein step C comprises
`steps of:
`the step of:
`A) assigning a first time-slot to a first of the plurality
`C1) identifying the second communication unit to
`of communication units to produce an assigned
`produce a requestor identification (ID).
`time-slot;
`9. The method of claim 8, wherein step D comprises
`B) updating, in response to a predetermined indicia
`the step of:
`received from the first communication unit during
`D1) updating the assigned communication resource
`a first communication, a slot descriptor field of the
`such that the requestor ID is conveyed to the sec
`assigned time-slot, such that the assigned time-slot
`ond communication unit.
`is reserved for use by members of the communica
`45
`10. In a radio communication unit which is a member
`tion group;
`of a communication group, a method of responding to a
`C) receiving, on the reserved time-slot from a second
`first communication transmitted on an assigned commu
`communication unit, a request to transmit a second
`nication resource, via a second communication trans
`communication;
`mitted on the assigned communication resource, the
`D) re-configuring, in response to the request, the
`radio communication unit being in communication with
`reserved time-slot to allow transmission of the sec
`a radio communication controller, the method compris
`ond communication on the assigned time-slot; and
`ing the steps of:
`E) measuring a transmission parameter for the second
`A) determining whether the first communication
`communication unit.
`resource has been configured as a reserved commu
`18. The method of claim 17, wherein step E com
`55
`nication resource;
`prises the step of:
`B) sending to the radio communication controller, on
`E1) determining a time advance value based on a
`the reserved communication resource, a request-to
`propagation delay characteristic of the request
`transmit the second communication;
`received from the second communication unit.
`C) determining whether the reserved communication
`19. The method of claim 18, wherein step D com
`resource has been re-configured to accept the sec
`prises the step of:
`ond communication; and
`D1) updating the slot descriptor field of the assigned
`D) transmitting, responsive to the step of determining
`time-slot such that the time advance value is con
`whether the reserved communication resource has
`veyed to the second communication unit.
`been re-configured, the second communication on
`20. The method of claim 17, wherein step E com
`65
`the assigned communication resource.
`prises the step of:
`11. The method of claim 10, further comprising the
`E1) determining a power control value of the request
`step of:
`received from the second communication unit.
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`Ex. 1019 / Page 8 of 9
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`5,299,199
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`C) determining whether the reserved time-slot has
`21. The method of claim 20, wherein step D com
`been reconfigured to accept the second communi
`prises the step of
`cation;
`D1) updating the slot descriptor field of the assigned
`D) transmitting, responsive to the step of determining
`time-slot such that the power control value is con
`whether the reserved time-slot has been re-con
`veyed to the second communication unit.
`figured, the second communication on the assigned
`22. In a time-division multiple-access (TDMA) radio
`time-slot; and
`E) determining a time advance value for the commu
`communication unit which is a member of a communi
`nication unit based on a present transmission pa
`cation group, a method of responding to a first commu
`rameter for the communication unit.
`nication transmitted on an assigned time-slot via a sec
`23. The method of claim 22, wherein step E com
`ond communication transmitted on the assigned time
`prises the step of:
`slot, the radio communication unit being in communica
`E1) receiving the time advance value from the radio
`tion with a radio communication controller, the method
`controller.
`comprising the steps of:
`24. The method of claim 22, wherein step E com
`15
`prises the steps of:
`A) determining whether the first time-slot has been
`E1) receiving the present transmission parameter
`configured as a reserved time-slot;
`from the radio controller; and
`B) sending to the radio communication controller, on
`E2) calculating the time advance value based on the
`the reserved time-slot, a request-to-transmit the
`received present transmission parameter.
`20
`second communication;
`
`O
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`Ex. 1019 / Page 9 of 9
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