(12) United States Patent
`Lyer et al.
`
`USOO629545OB1
`(10) Patent No.:
`US 6,295,450 B1
`(45) Date of Patent:
`Sep. 25, 2001
`
`(54) METHOD AND APPARATUS FOR
`TRANSFERRING COMMUNICATION
`WITHIN A COMMUNICATION SYSTEM
`
`(75) Inventors: Subramanian S. Lyer, Mundelein;
`
`Jeetendra G. Deshmukh, Vernor Hills,
`See Spa skis, her, D.
`uSal, St. Uharles, all O
`(73) Assignee: Motorola, Inc., Schaumburg, IL (US)
`(*) Notice:
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`(21) Appl. No.: 09/103,228
`22) Filled:
`Jun. 23, 1998
`(22)
`9
`(51) Int. Cl." ................................................... H04Q 7/20
`(52) U.S. Cl. .......................... 455/436: 455,417; 455/452;
`455/524; 455/525
`(58) Field of Search ..................................... 455/452, 524,
`455/525, 436, 437, 438, 439,517, 417:
`s 370,346 34s 335 326 455
`References Cited
`U.S. PATENT DOCUMENTS
`1/1988 Brenig ................................., 455/436
`6/1995 Barnett et al. ....................... 455/436
`
`4,718,081
`5,428,816
`
`(56)
`
`
`
`
`
`4/1996 Jonsson et al. ...................... 455/436
`5,513,246
`9/1997 Turcotte et al. ..................... 455/436
`5,666,650
`12/1997 Kallin et al. ......................... 455/434
`5,701,585
`5,729.542 * 3/1998 Dupont ................................. 370/346
`5.
`: 3.
`incide a- - - - - - - - - - - - - - - - - - - - 3.85
`
`5/1998 scholefield et al. . 455/452
`5,752.193
`7/1998 Persson et al. ...................... 455/434
`5,778,316
`6/1999 Mitts et al. .......................... 370/331
`5,912,885
`6/1999 Tiedemann et al. ................. 370/348
`5,914,950
`5,915,221 * 6/1999 Sawyer et al. ....................... 455/437
`6,119,005
`9/2000 Smolik ................................. 455/436
`* cited by examiner
`
`Primary Examiner Lee Nguyen
`Assistant Examiner Simon Nguyen
`(74) Attorney, Agent, or Firm-Kenneth A. Haas
`(57)
`ABSTRACT
`Transferring communication within a communication Sys
`tem (100) occurs as follows: During communication with a
`serving base station (101), a handover candidate list (110) is
`provided to the remote unit (113). The list (110) comprises
`a set of neighboring base stations (102) that are capable of
`Supporting the Service requirements of the remote unit (113)
`and does not include any neighboring base station (111) that
`are incapable of Supporting the current Service required by
`the remote unit.
`
`10 Claims, 2 Drawing Sheets
`
`116
`-4-
`
`117
`
`110 7-1 A13
`
`REMOTE
`UNIT
`
`116
`
`116
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`U.S. Patent
`
`Sep. 25, 2001
`
`Sheet 1 of 2
`
`US 6,295,450 B1
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`Ex.1019
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`U.S. Patent
`
`Sep. 25, 2001
`
`Sheet 2 of 2
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`US 6,295,450 B1
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`IDENTIFY A NUMBER OF BASE STATIONS h 200
`
`IDENTIFY CAPABILITIES OF THE
`BASE STATION
`
`2O2
`
`CATHER INFORMATION ON REMOTE UNIT h 204
`
`BASED ON STEPS 202,204, GENERATE
`LIST OF CANDIDATE BASE STATIONS
`
`206
`
`TRANSMIT LIST TO REMOTE UNIT
`
`212
`
`MONITOR SIGNAL QUALITY PARAMETERS h 214
`
`DETERMINE LIST OF BASE STATIONS
`FOR MEASUREMENT REPORTING
`
`215
`
`REPORT MEASUREMENTS TO BASE STATION 216
`
`PERFORM HANDOFF
`
`218
`
`FIC. 2
`
`
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`DETERMINE NEICHBOR CAPABILITIES
`
`3 O 1
`
`COMPLIE A LIST BASED ON
`NEIGHBOR CAPABILITIES
`
`303
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`BROADCAST LIST TO REMOTE UNIT
`
`305
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`307
`
`FI C. 3
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`15
`
`1
`METHOD AND APPARATUS FOR
`TRANSFERRING COMMUNICATION
`WITHIN A COMMUNICATION SYSTEM
`FIELD OF THE INVENTION
`The present invention relates generally to cellular com
`munication Systems and, in particular, to transferring a
`remote unit's communication among base Stations within
`Such cellular communication Systems.
`BACKGROUND OF THE INVENTION
`Communication Systems are well known and consist of
`many types including land mobile radio, cellular
`radiotelephone, personal communication Systems, and other
`communication System types. Within a communication
`System, transmissions are conducted between a transmitting
`device and a receiving device over a communication
`resource, commonly referred to as a communication chan
`nel. To date, the transmissions have typically consisted of
`Voice signals. More recently, however, it has been proposed
`to carry other forms of Signals, including high-speed pack
`etized data Signals. For ease of operation, it is preferable to
`have the data transmission capability overlay the existing
`Voice communication capability, Such that its operation is
`essentially transparent to the Voice communication System
`while Still utilizing the communication resources and other
`infrastructure of the Voice communication System.
`One Such communication System currently being devel
`oped with transparent data transmission capabilities is Gen
`eral Packet Radio Service (GPRS) system as described in the
`Global System for Mobile Communications (GSM) Tech
`nical Specification (TS) 2.60 and incorporated by reference
`herein. Within such a communication system a GSM com
`munication system is overlaid with a GPRS communication
`system. In contrast to GSM's service model, which offers
`telephony on demand, GPRS’s service model offers a wire
`less Wide Area Network (WAN) supporting a wide range of
`applications Such as low-volume intermittent telemetry,
`Video, web browsing, and the transfer of large amounts of
`data.
`In Such a System, each remote unit may have specific
`Service requirements, which include the remote unit's
`requirements for the communications network to provide
`Support for a certain call type (e.g. voice, video, data) and
`channel coding (e.g. full rate, half rate) as well as certain
`quality of Service (QoS) parameters. (QoS parameters
`Specify the remote unit's requirements for the network to
`Support constraints Such as bounded transfer delays and
`Specified data throughput). In Such a System, an active
`remote unit may be engaged in multiple calls of various or
`Similar types, each call having various QoS parameters.
`Additionally, each base Station may have Specific capabili
`ties that it is capable of Supporting, (Such as Services needed
`to Support a particular call type, channel coding Services,
`and Statically configured QoS classes). Abase station will be
`configured to provide a set of QoS classes, however, at a
`Specific point in time, a particular QoS class may not be
`available due to the varying demand on that base Station for
`that QoS class. Thus, currently available QoS classes in a
`base Station is dynamic while the Set of QoS classes con
`figured in a base Station is Static. Individual base Stations
`may not be equipped with the capability to Support a remote
`unit's Specific Service requirements. For example, Some base
`stations may not have GPRS capabilities while their neigh
`boring base stations are GPRS capable.
`65
`The current base station monitoring process in GSM/
`GPRS uses a static list of neighboring base stations to aid in
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`transferring communication among base Stations, which is
`described in detail in GSM recommendation 5.08. AS
`described, the remote unit monitors all the base Stations in
`a Static list and reports measurements for a Subset of the list
`having the best Signal quality. Hence, base Stations that may
`not Satisfy a remote unit's Service requirements are unnec
`essarily monitored and reported by the remote unit to its
`Serving base Station. Therefore, a need exists for a method
`and apparatus for transferring a remote units communica
`tion within a communication System that does not needlessly
`monitor and report neighboring base Stations that do not
`Satisfy a remote unit's Service requirements.
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is a block diagram of a communication System in
`accordance with the preferred embodiment of the present
`invention.
`FIG. 2 is a flow chart illustrating operation of the com
`munication System of FIG. 1 in accordance with the pre
`ferred embodiment of the present invention.
`FIG. 3 is a flow chart showing operation of the commu
`nication System of FIG. 1 in accordance with an alternate
`embodiment of the present invention.
`DETAILED DESCRIPTION OF THE DRAWINGS
`In order to address this need and others, transferring
`communication within a communication System occurs as
`follows: During communication with a Serving base Station,
`a handover candidate list is provided to the remote unit. The
`list comprises a Set of neighboring base Stations that are
`capable of Supporting the Service requirements of the remote
`unit and does not include any neighboring base Station that
`are incapable of Supporting the current Service required by
`the remote unit. Because the handover candidate list con
`tains only neighboring base Stations that are capable of
`Satisfying the remote unit's Service requirements, the remote
`unit will not needlessly monitor and report Signal quality for
`base Stations that will not Satisfy the remote units require
`ments. Consequently, the remote unit will be handed over to
`a neighboring base Station that can best Support the remote
`unit's Service requirements for a maximal Subset of the
`remote unit's currently active calls.
`The present invention includes a method for transferring
`communication within a communication System. The
`method comprises the Steps of determining a plurality of
`neighboring base Stations, determining a plurality of base
`Station capabilities for the plurality of neighboring base
`Stations, and determining a current Service required by a
`remote unit. In the preferred embodiment of the present
`invention a list is transmitted to the remote unit. The list
`comprises a Set of base Stations within the plurality of
`neighboring base Stations that are capable of Supporting the
`current Service required by the remote unit. The list addi
`tionally does not include neighboring base Stations that are
`incapable of Supporting the current Service required by the
`remote unit. In the preferred embodiment, the list is utilized
`by the remote unit in transferring communication within the
`communication System.
`The present invention additionally encompasses a method
`for transferring communication within a communication
`System. The method comprises the Steps of determining a
`plurality of neighboring base Stations, determining a plural
`ity of base Station capabilities for the plurality of neighbor
`ing base Stations, and determining a current Service required
`by a remote unit. Next, Signal quality is measured for
`individual base stations within a set of the plurality of
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`US 6,295,450 B1
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`15
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`3
`neighboring base Stations and a list of individual base
`Stations within the Set of the plurality of neighboring base
`stations is determined. In the preferred embodiment of the
`present invention the list includes those base Stations that are
`capable of Supporting the current Service required by the
`remote unit, and does not include neighboring base Stations
`that are incapable of Supporting the current Service required
`by the remote unit.
`Finally, the present invention encompasses an apparatus
`for transferring communication within a communication
`System. The apparatus includes a logic unit for determining
`a list. In the preferred embodiment, the list comprises a Set
`of base Stations, within a plurality of neighboring base
`Stations, that are capable of Supporting a current Service
`required by a remote unit, the list additionally does not
`include base Stations neighboring a Serving base Station that
`are incapable of Supporting the current Service required by
`the remote unit.
`Turning now to the drawings, wherein like numerals
`designate like components, FIG. 1 is a block diagram of
`communication system 100 in accordance with the preferred
`embodiment of the present invention. In the preferred
`embodiment, communication system 100 comprises a GSM
`system overlaid with a GPRS system, but in alternate
`25
`embodiments communication system 100 may utilize other
`analog or digital cellular communication System protocols
`Such as, but not limited to, the Narrowband Advanced
`Mobile Phone Service (NAMPS) protocol, the Advanced
`Mobile Phone Service (AMPS) protocol, the Code Division
`Multiple Access (CDMA) system protocol, the Personal
`Digital Cellular (PDC) protocol, the United States Digital
`Cellular (USDC) protocol, or the Cellular Digital Packet
`Data (CDPD) protocol.
`The GSM system is comprised of a number of network
`elements including Serving Base Transceiver Station or base
`station (BTS) 101, neighboring base stations 102 and 111,
`Base Station Controller (BSC) 103, and Mobile Switching
`Center (MSC) 104. The GPRS system network elements
`include base station 101, base station 102, base station 111,
`BSC 103, Serving GPRS Support Node (SGSN) 105, and
`Gateway GPRS Support Node (GGSN) 106. In the preferred
`embodiment of the present invention, all network elements
`are available from Motorola, Inc. (Motorola Inc. is located
`at 1301 East Algonquin Road, Schaumburg, Ill. 60196).
`SGSN 105 controls users access to the GPRS network in
`terms of Subscription checking and overall traffic load
`situations, while GGSN 106 is the GPRS equivalent to a
`gateway function, which connects the GPRS network to
`external private or public networks 108-109. It is contem
`plated that network elements within communication System
`100 are configured in well known manners with processors,
`memories, instruction Sets, and the like, which function in
`any Suitable manner to perform the function Set forth herein.
`Operation of communication system 100 in accordance
`with the preferred embodiment of the present invention will
`be described below utilizing a mobile assisted handover
`(MAHO) to describe a remote unit's transfer of communi
`cations from one base Station to another. Although the
`preferred embodiment will be described with reference to
`MAHO, an alternate embodiment of the present invention
`utilizes a cell reselection method as described in TS 3.22 for
`transferring communications from one base Station to
`another.
`During typical operation, remote unit 113 moves through
`out a coverage area of Serving base Station 101 and Serving
`base Station 101 monitors a signal quality metric (e.g.,
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`RXLEV or received Bit Error Rate (BER)) of the remote
`units uplink communication Signal. Additionally, remote
`unit 113 monitors a Signal quality metric of the neighboring
`base Stations and reports the result to the Serving base
`Station. To account for changes in Signal quality as remote
`unit 113 moves throughout communication system 100, base
`station 101 will issue commands directing remote unit 113
`to handover to a base Station that can better Serve remote unit
`113 (e.g., neighboring base Station 102). More particularly,
`handover within communication system 100 in accordance
`with one embodiment of the present invention occurs as
`follows:
`During communication with base station 101, list 110 is
`provided to remote unit 113 via transceiver 121 and down
`link communication signal 116. In the preferred embodiment
`of the present invention list 110 comprises a set of neigh
`boring base Stations (e.g., base Station 102) that are capable
`of Supporting the Service requirements of remote unit 113.
`Remote unit 113 performs signal quality measurements of
`transmissions from all the base Stations in the neighbor list.
`In the preferred embodiment of the invention, using the
`Signal quality measurements of neighboring base Stations,
`remote unit 113 generates and transmits a signal quality
`measurements report 117, to serving base station 101, for a
`Subset of listed base Stations that have the best Signal quality.
`This measurement report is Sent via uplink communication
`signal 119, and received by transceiver 121. When serving
`base station 101 determines that a handover of remote unit
`113 is needed, base station 101 sends handover instructions
`to remote unit 113 via downlink communication signal 116,
`that instructs remote unit 113 to handover to a neighboring
`base station on list 117 that can best serve remote unit 113.
`FIG. 2 is a flow chart showing more detailed operation of
`communication system 100 in accordance with the preferred
`embodiment of the present invention. In the following
`description it is assumed that remote unit 113 is actively
`communicating to base Station 101 or is in a Suspended State,
`in which it actively or periodically monitors a control
`channel for notification of any pending transmission by base
`Station 101.
`The logic flow begins at step 200 where logic unit 123
`determines a list of base Stations that potentially are able to
`service remote unit 113. In the preferred embodiment of the
`present invention, logic unit 123 determines a plurality of
`neighboring base Stations Surrounding Serving base Station
`101 (e.g., base station 102 and base station 111).
`Next, at step 202, capabilities associated with the base
`stations identified at step 200 are determined by logic unit
`123. Capabilities of neighboring base Stations may be deter
`mined by a Serving base Station in any Suitable manner. In
`the preferred embodiment of the present invention, three
`methods for determining Such capabilities are envisioned.
`Firstly, logical signaling links (not shown) can be provided
`between neighboring base Stations (i.e., base stations 101,
`102 and 111). Messaging is then used to exchange base
`Station capabilities between neighboring base Stations. Such
`messages include the capabilities of the base Station Sending
`the message. Secondly, base Station capability information
`for each base station within communication system 100 may
`be contained within a shared database (not shown) acces
`Sible by each base Station within communication System
`100. Thirdly, information on base station capability may be
`broadcast to remote units by neighboring base Stations
`within communication system 100 over control channels
`such as Broadcast Control Channels (BCCHs), Packet
`Broadcast Control Channels (PBCCHs), or any suitable
`communication channel. Remote units within communica
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`S
`tion system 100 then may relay the neighboring base station
`capability information to their respective Serving base Sta
`tion. The base stations receive the capabilities of other base
`Stations by receiving the capabilities relayed by the remote
`unit.
`Continuing, at Step 204 information relating to Service
`requirements of remote unit 113 is determined by logic unit
`123. In the preferred embodiment of the present invention
`this determination is made by logic unit 123 analyzing the
`remote unit's Service requirements for the current call(s).
`Based on the information determined at steps 202 and 204,
`at step 206 logic unit 123 determines list110 of neighboring
`base stations (e.g., base station 102) that remote unit 113 will
`use for monitoring measurements.
`It should be noted, in the preferred embodiment of the
`present invention it is anticipated that remote unit 113 has a
`mandatory Set of Service requirements and an optional Set of
`Service requirements. For example, if a remote unit is
`engaged in two simultaneous Sessions of data transfer with
`different data rates, one of these Sessions may be a manda
`tory Service and the other may be an optional Service. In the
`preferred embodiment of the present invention, any neigh
`boring base Station that does not Support the mandatory
`Service requirements of the remote unit will not be a
`candidate for list 110.
`At step 212 list 110 is transmitted to remote unit 113 via
`transceiver 121. In the preferred embodiment of the present
`invention, list 110 is transmitted individually by the serving
`base station 101 to remote unit 113 (i.e., not to other remote
`units within communication system 100), via a control
`channel Such as Packet ASSociated Control Channel
`(PACCH). List 110 comprises a set of neighboring base
`Stations that are capable of Supporting the current Service
`required by the remote unit (e.g., base station 102). In other
`words, list110 does not include any neighboring base Station
`(e.g., base Station 111) that is incapable of Supporting the
`current Service required by the remote unit.
`In an alternate embodiment of the present invention, at
`Step 212 base Station capability information and currently
`available QoS classes of neighboring base Stations is also
`transmitted to remote unit 113. Two methods of performing
`this function are envisioned. Firstly, the Serving base Station
`101 will Send this information regarding the neighboring
`base Stations to remote unit 113 through Signaling, after
`obtaining this information as described in Step 202.
`Secondly, each neighboring base Station (e.g., 102 and 111)
`will broadcast this information on its BCCH/PBCCH or any
`Suitable control channel. Remote unit 113 will use this
`information to modify the list of base stations (110) used for
`monitoring, by prioritizing the list based on a match of the
`base Station capabilities and currently available QoS classes
`with the remote unit's Service requirements.
`Continuing, at Step 214, remote unit 113 monitorS Signal
`quality measurements of transmissions from all base Stations
`in list 110. The quality parameters may be signal Strength
`(RXLEV), and other parameters such as Bit Error Rate
`(BER), Frame Erasure Rate (FER), etc.
`At step 215, remote unit 113 determines a Subset of the
`listed base stations (subset of list 110) whose signal quality
`measurements 117 will be reported to the serving base
`station 101. In the preferred embodiment of this invention,
`remote unit 113 will use the Signal quality measurements of
`neighboring base Stations to determine the Subset of base
`stations from list110 with the best signal quality for report
`ing. In an alternate embodiment, remote unit 113 will use the
`Signal quality measurements, base Station capability and
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`currently available QoS classes of neighboring base Stations
`to determine the Subset of base stations that have the best
`Signal quality and that best meet the remote unit's Service
`requirements for reporting. Signal quality measurements
`report 117 is then provided to serving base station 101 (step
`216).
`Finally, at step 218, base station 101 hands off remote unit
`113 to a neighboring base Station (e.g., 102). In one aspect
`of the preferred embodiment of the present invention, logic
`unit 123, using measurement reports received from remote
`unit 113 at Step 216, determines a particular neighboring
`base station from report 117, that best meets remote units
`Service requirements. In an alternative embodiment of the
`present invention the currently available QoS classes of the
`neighboring base Stations are taken into consideration by the
`Serving base Station when handing over remote unit 113.
`Continuing, base Station 101 then sends a handover com
`mand to remote unit 113 via downlink communication Signal
`116 instructing remote unit 113 to handover to the chosen
`neighboring base Station. In an alternate embodiment of the
`present invention, remote unit 113 performs base Station
`reselection from the list of base stations reported in 117.
`Because list 110 contains only neighboring base Stations
`that are capable of Satisfying the remote unit's Service
`requirements, remote unit 113 will not monitor and report
`Signal quality for base Stations that will not Satisfy the
`remote unit's requirements. Consequently, remote unit 113
`will be handed over to a neighboring base Station that can
`best Support the remote unit's Service requirements for a
`maximal Subset of the remote unit's currently active calls.
`FIG. 3 is a flow chart showing operation of communica
`tion system 100 in accordance with an alternate embodiment
`of the present invention. In the alternate embodiment of the
`present invention, neighboring base Station capability list
`110 is broadcast to all remote units currently being served by
`base station 101 over a common control channel (CCCH).
`The logic flow begins at step 301 where base station 101
`determines the base Station capabilities of all neighboring
`base stations, as described in step 202 of FIG.2. Next, at step
`303, a neighboring base station capability list110 is formed
`comprising identification information of all neighboring
`base stations along with their capabilities. At step 305 list
`110 is broadcast to all remote units served by base station
`101 over a CCCH. Remote unit 113 utilizes list110 to create
`a candidate Set of base Stations that can Satisfy its Service
`requirements, and then continues to monitor only those base
`stations (step 307).
`The descriptions of the invention, the Specific details, and
`the drawings mentioned above, are not meant to limit the
`Scope of the present invention. For example, although logic
`unit 123 and neighboring list 125 are depicted within BTS
`101, these elements may be located within other network
`elements (e.g., BSC 103). It is the intent of the inventors that
`various modifications can be made to the present invention
`without varying from the Spirit and Scope of the invention,
`and it is intended that all Such modifications come within the
`Scope of the following claims and their equivalents.
`What is claimed is:
`1. A method for transferring communication within a
`communication System, the method comprising the Steps of:
`determining a plurality of neighboring base Stations that a
`remote unit is capable of monitoring;
`determining a plurality of base Station capabilities for the
`plurality of neighboring base Stations, wherein the
`plurality of base Stations capabilities are from the group
`consisting of an ability to provide a Video call, an
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`ability to provide a data call, an ability to provide a
`bounded transfer delay, and an ability to provide a
`Specified data throughput,
`determining a current Service required by the remote unit
`wherein the current Service taken from the group con
`Sisting of a Video call, a data call, a bounded transfer
`delay, and a specified data throughput, and
`transmitting to the remote unit, a list comprising a Set of
`base Stations from the plurality of neighboring base
`Stations, that are capable of Supporting the current
`Service required by the remote unit, the list additionally
`not including neighboring base Stations that are inca
`pable of Supporting the current Service required by the
`remote unit wherein the list is utilized by the remote
`15
`unit for transferring communication within the com
`munication System.
`2. The method of claim 1 wherein the step of transmitting
`to the remote unit further comprises the Step of transmitting
`a plurality of base Station capabilities to the remote unit.
`3. The method of claim 1 wherein the step of determining
`the plurality of base station capabilities for the plurality of
`neighboring base Stations comprises the Step of receiving the
`plurality of base Station capabilities from the remote unit.
`4. The method of claim 1 further comprising the step of
`determining a specific base Station that best meets the
`Service requirements of the remote unit for transferring
`communication within the communication System to the
`Specific base Station.
`5. A method for transferring communication within a
`communication System, the method comprising the Steps of:
`determining a plurality of neighboring base Stations that a
`remote unit is capable of monitoring;
`determining a plurality of base Station capabilities for the
`plurality of neighboring base Stations, wherein the
`plurality of base Stations capabilities are from the group
`consisting of an ability to provide a Video call, an
`ability to provide a data call, an ability to provide a
`bounded transfer delay, and an ability to provide a
`Specified data throughput,
`determining a current Service required by the remote unit,
`wherein the current Service taken from the group con
`Sisting of a Video call, a data call, a bounded transfer
`delay, and a specified data throughput,
`measuring Signal quality for individual base Stations
`within a Set of the plurality of neighboring base sta
`tions, and
`determining a list of individual base Stations from the
`plurality of neighboring base Stations that are capable
`
`25
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`8
`of Supporting the current Service required by the remote
`unit, the list additionally not including neighboring
`base Stations that are incapable of Supporting the cur
`rent Service required by the remote unit wherein the list
`is utilized by the remote unit for transferring commu
`nication within the communication System.
`6. The method of claim 5 wherein the step of measuring
`Signal quality for individual base Stations within the Set of
`the plurality of neighboring base Stations comprises the Steps
`of:
`determining a plurality of base Stations within the plural
`ity of neighboring base Stations that meet the current
`Service required by the remote unit to create a set of the
`plurality of neighboring base Stations, and
`measuring Signal quality for individual base Stations
`within the set of the plurality of neighboring base
`Stations.
`7. An apparatus for transferring communication within a
`communication System, the apparatus comprising:
`a logic unit for determining a list of base Stations from a
`plurality of neighboring base Stations capable of being
`monitored by a remote unit;
`wherein the list comprises a set of base Stations that are
`capable of Supporting a current Service required by the
`remote unit;
`wherein the list additionally does not include base Stations
`neighboring a Serving base Station that are incapable of
`Supporting the current Service required by the remote
`unit,
`wherein the list is utilized for transferring communication
`within the communication System; and
`wherein the current Service required by the remote unit is
`a Service taken from the group consisting of a Video
`call, a data call, a bounded transfer delay, and a
`Specified data throughput.
`8. The apparatus of claim 7 further comprising a trans
`ceiver for transmitting the list to the remote unit.
`9. The apparatus of claim 7 wherein the communication
`system is a Global System for Mobile Communications
`(GSM) system overlaid with a General Packet Radio Service
`(GPRS) system.
`10. The apparatus of claim 7 further comprising a trans
`ceiver for receiving base Station capabilities that are broad
`cast from the plurality of neighboring base Stations.
`
`k
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`k
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`k
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`k
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`k
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`US 6,295,450 B1
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`Ex.1019
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`

`

`UNITED STATES PATENT AND TRADEMARK OFFICE
`CERTIFICATE OF CORRECTION
`
`PATENT NO. : 6,295,450 B1
`DATED
`: September 25, 2001
`INVENTOR(S) : Iyer et al.
`
`Page 1 of 1
`
`it is certified that error appears in the above-identified patent and that said Letters Patent is
`hereby corrected as shown below:
`
`Title page,
`Item 75), Inventor: first inventor reads "Subramanian S. Lyer', should be
`-- Subramanian S. Iyer --
`
`Signed and Sealed this
`
`Fourteenth Day of May, 2002
`
`Aftest:
`
`Attesting Officer
`
`JAMESE, ROGAN
`Director of the United States Patent and Trademark Office
`
`Ex.1019
`APPLE INC. / Page 8 of 8
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