Title of Invention

METHOD FOR PROVIDING BEARER FORMAT TYPE CAPABILITIES IN A CELLULAR COMMUNICATION SYSTEM AND SYSTEM FOR DISTRIBUTING BEARER FORMAT TYPE INFORMATION

Abstract A communication system (100) provides for a distribution of bearer format type information among Network Ele- ments (110 ,130, 160, 170) located along a bearer path of a commumcatation seasion, thereby faclitating a selection of a bearer format type for the communication session. The bearer format type information informs of bearer format types supported by each of the Network elements. In one embodiment of the present invetion, the bearer from types are conveyed in bearer format type data fields (301-303) of bearer format type massage (300), which data fields may be modified by each Network Element in order to identify the bearer format type capabilities of the Network Element.
Full Text WO 2005/057799 PCT/US2004/040809
1.
METHOD AND APPARATUS FOR PROVIDING BEARER FORMAT TYPE
INFORMATION IN A CELLULAR COMMUNICATION SYSTEM
Cross-referance to Related Application(s)
This application is related to U.S. Patent Application No. 60/487,182, attorney
dockat no..CE11713R, filed July 17, 2003, and further claims priority from provisional
application aerial no 60/527,949, entitled "METHOD AND APPARATUS FOR
PROVIDING DEARER FORMAT TYPE INFORMATION IN A CELLULAR
COMMUNICATION SYSTEM " filed December 8, 2003, which is commonly owned
and incorporated herein by reference in its entirety.
Field of the Invention
The present invention relates generally to cellular communication systems, and, in
particular, to transcoding functionality in a cellular communication system.
Background of the Invention
In a typical Code Division Multiple Access (CDMA) cellular network, such as a
second generation (2G) CDMA communication network, transcoders are located in each.
of an originating mobile station (MS), a terminating MS, and abase station (BS), and in
particular in a base station controller (BSC), serving each of the originating and
terminating MS8. The transcoder of "the BS serving the originating MS receives
compressed voice packets from the MS eed converts the voice packets to pulse code
modulated (PCM) signals for transmission through a circuit switched core network:
included in the cellular network. The BS then transmits the PCM signals upstream
through the circuit switched core network and, via the core network to a Public Switched.
Telephone Network (PSTN) coupled to the operator's cellular network. Similarly, PCM
signals received by a 2G CDMA cellular network from a PSTN that are intended for the
terminating MS are transmitted as PCM signals through the circuit Switched core network.
to the BS servicing the terminating MS, where the transcoder in the BS converts the PCM

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signals to compressed voice packets. The BS then transmits the compressed voice
packets to the terminating MS.
The development of next generation CDMA, networks, such as a cdms2000
cellur network, have allowed system operators to install Packet Switched core networks
in place of, or in parallel with, the circuit switched cope networks, thereby permitting data
packets to be transmitted through the cellular networks in place of, or in parallel with
circuit switched signals. The installation of such Packet Switched core networks permits
a system operator to transmit voice data as a compressed voice packet through the Packet
Switched core network, rather than transmit voice data as PCM signals through the circuit
switched core network. To facilitate transmission of voice through a cellular network in a
data packet format, operators of cdma2000 cellular networks have expressed an interest in
relocating the transcoders closer to the PSTN. In addition, a relocation of transcoders to a
more centralized location deeper in the cellular network can reduce system costs by
providing a more centralized transcoder function, as opposed to a widely distributed, B8-
based, transcoder function, and by permitting voice services to be transported over more
of a backhaul network in a compressed format as opposed to an uncompressed formal
However, when a legacy CDMA communication system is upgraded with a
relocated transcoder function, a result may be a provision of a transcoding function in
each of a core network and a BS, Furthermore, some systems may service mobile stations
that are not capable of transmitting voice in a format compatible for transmission over a
Packet Switched core network, thus necessitating a transcoding fraction in a BS. A result
is that multiple transcoding functions may reside along a voice signal's path, which
multiple transcoding functions may each support a same or different bearer format type.
In boder to determine an appropriate bearer format type for a communication session
involving an originating mobile station (MS) and a terminating MS, the transcoding
capabilities of the originating and terminating MSs, as well as the transcoding capabilities
of any transcoding functions residing along a voice bearer path associated with the MSs,
must be made known to a decision-making entity.
In addition, each time voice is re-encoded/re-decoded, by a transcoder a quality of
the voice degrades. As a result, the standards underlying the next generation CDMA

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networks Further allow for, but do not specify implementation of, transcoder-free
operation (TrFO), wherein voice is transmitted (trough the cellular network without
application to the voice, by the network, of any transocoder function. However, in order
to for a cellular network to engage in transcoder-free operation or to engage appropriate
transcoders into operation, the network must determine the most appropriate bearer
format type to be supported by each of the Network Elements involved in the call,
including an originating MS and the terminating MS for the case of mobile-to-mobile
calls.
Therefore, there exists a need for a method and apparatus for determining the
bearer format type capabilities of each MS involved in a communication session and
further of the transcoding functions within Network Elements (for example, Media
Gateways) located along a voice bearer path associated with the tall session.
Brief Description of the Drawings
FIG. 1 is a block diagram of a wireless communication system in accordance with
am embodiment of the present invention.
FIG. 2A is a logic flow diagram 200 of steps executed by the communication
system of FIG. 1 in distributing information concerning the bearer format type
capabilities of each mobile station engaged in a communication session and each network
transcoder located along a voice bearer path associated with the mobile stations in
accordance with various embodiments of the present invention.
FIG. 2B is a continuation of the logic flow diagram of FIG. 2A depicting steps
executed by the communication system of FIG, I in distributing information concerning
the bearer format type capabilities of each mobile station engaged in a communication
session and of each network transcoder located along a voice bearer path associated with
the mobile stations in accordance with various embodiments of the present invention
FIG. 2C is a continuation of the logic flow diagrams of FIGs. 2A and 2B depicting
steps executed by the. conuxntnication system of FIG, 1 in distributing information
concerning the bearer format type capabilities of each mobile station engaged in a

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communication session and of each network transcoder located along a voice bearer path
associated with the mobile stations in accordance with various embodiments of the
present invention.
FIG. 2D is a Continuation of the logic flow diagrams of FIGs. 2A, 2B, and 2C
depicting steps executed by the communicalion system of FIG. 1 in distributing
information concerning the bearer formal type capabilities of each mobile station engaged
in a communication session and of each network transcoder located along a voice bearer
path associated with the mobile stations in accordance with various embodiments of the
present invention.
FIG. 3 is a black diagram of an exemplary bearer format type message that may be
used by the communication system of FIG. 1 to distribute in the bearer format type
capabilities of each mobile station engaged in a communication, session and of each
network transcoder located along a voice bearer path associated with the mobile stations
in accordance with an embodiment of the present invention.
FIG. 4 is a logic flow diagram of steps executed by a base station of FIG. 1 in
assembling the bearer format type message of FIG. 3 in accordance with an embodiment
of the present invention.
FIG, 5 is a logic flow diagram of steps executed by a Packet Switch of FIG. 1 in
modifying bearer format type data fields of the bearer format type message of FIG. 3 in
accordance with an embodiment of the present invention.
Detailed Description of the Invention
To address the need far a method and apparatus for determining the bearer format
type capabilities of each mobile station involved in a communication session and further
of the transcoding function within Network Elements (for example, Media Gateways)
located along a voice bearer path associated with the call session, a communication
system is provided that distributes bearer format type information among Network
Elements located along a bearer path of a communication session, thereby facilitating a
selection of a bearer format type for the communication session. The bearer format type

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information informs of bearer format types supported by each of the Network Elements.
In one embodiment of the present invention the bearer format types are conveyed in
bearer format type data fields of bearer format type messages, which data fields may be
modified by each Network Element in order to identify the bearer format type capabilities
of the Network Element
Generally, an embodiment of the present invention encompasses a method for
providing beaier format type capabilities in a cellular communication system. The
method includes assembling a message comprising bearer format type information,
wherein the bearer format type information, comprises. When a first beaier format type is
assigned to a mobile station, the assigned beaier format type, and further comprises, when
the mobile station and a Network Element serving the mobile station mutually support a
second bearer format, the second bearer format and conveying the assembled message.
Another embodiment of the present invention encompasses a method for
providing bearer format type capabilities in a cellular communication system. The
method includes receiving bearer format type information comprising at least ons of a
first bearer format type assigned to a mobile station and a second bearer format type
mutually supported by the mobile station ami a base station serving the mobile station and
conveying the received beater format type information to a Network Element other than
the base station.
Still another embodiment of the present invention encompasses a method for
providing hearer formal type capabilities in a cellular communication system. The
method includes receiving bearer format type information comprising at least one of a
first bearer format type assigned to a first mobile station and a second bearer format type
mutually supported by the first mobile station and a base station serving the first mobile
station and assigning a bearer format type to a second mobile station based on the
received bearer format type information.
Yet another embodiment of the present invention encompasses a method for
providing bearer format type capabilities in a cellular communication system, the method
comprising assembling a message comprising a first data field identifying a bearer format
type assigned to a mobile station and at least a second data field identifying a bearer

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format mutually supported by a mobile station and a base station serving hte mobile
station.
Still another embodiment of the present invention encompasses a method for
providing bearer format type capabilities in a cellular communication system. The
method includes conveying first bearer format type information, wherein the first bearer
format type information comprises, When a first bearer format type is assigned to a first
mobile station, the assigned bearer format type and further comprises, the assigned first
bearer format and, when the first mobile station and a first base station mutually support a
second bearer format, the second bearer format. The method further includes receiving
the first bearer format type information from the first base station, in response to
receiving the first bearer format type information, determining whether a first Network
Element other Chan the first base station and one or more of the first mobile station and
the first base station mutually support a third bearer format type, and further in response
to receiving the first bearer format type information, conveying second bearer format
information comprising the first bearer format type information and, when the first
Network Element and one or more of the first mobile station and the first base station
mutually support a third bearer format type, the third bearer format type. The method
further includes receiving the second bearer format type information, in response to
receiving the second, bearer format type information, determining whether a second.
Network Element other than the first base station and one or mote of the first mobile
station, the first base station, and the first Network Element mutually support a fourth
beater format type, and further in response to receiving the second bearer format type
information, conveying third bearer format type information comprising the received
second bearer format type information and, when the second Network Element and one or
more of the first mobile station, the first base station, and the first Network Element
mutually support a fourth bearer format type, the fourth bearer format type. The method
further includes receiving the third bearer format type information and, in response to
receiving the second bearer format type information, assigning a bearer format to a
second mobile station based on the third bearer format type information.
Yet another embodiment of the present invention encompasses a base station
controller that assembles a message comprising bearer format type information, wherein

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the bearer format type information comprises, when a first bearer format typa is assigned
to a mobile station, the assigned bearer format type, and further comprises, when the
mobile station and a Network Element serving the mobile station mutually support a
second bearer format the second bearer format, and conveys the assembled message.
Still another embodiment of the present invention encompasses a Packet Switch
comprising at least one memory device that maintains at least one bearer format type
supported by an associated transcoder. The Packet Switch further comprises a processor
coupled to the at least one memory device that receives bearer format type information
comprising at least one of a first bearer format type assigned to a mobile station and a
second bearer format type mutually supported by the mobile station and a base station
serving the mobile station and conveys the received bearer format type information to
another Network Element.
Yet another embodiment of the present invention, encompasses a base station
controller that receives bearer format type information comprising at least one of a first
bearer format type assigned to a first mobile station and a sword bearer format type
mutually supported by the first mobile station and a base station serving the first mobile
station and that assigns a bearer format type to a second mobile station based on the
received beaier format type information.
Still another embodiment of the present invention encompasses a computer
readable medium storing instructions for assembling a message comprising a first data
field identifying a bearer format type assigned to a mobile station and at least a second
data field identifying a bearer format mutually supported by a mobile station and a base
station serving the mobile station.
Yet another embodiment of the present invention encompasses a system for
distributing bearer format type information. The system includes a base station that
comprises a first transcoder and that conveys a message comprising bearer format type
information, wherein the bearer format type information comprises, when a first bearer
format type is assigned to a mobile station, the assigned bearer format type, and further
comprises, when the mobile station and the base station mutually support a second bearer
format, the second beater format. The system further includes a bearer format controller

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that receives the bearer format type information from the base station, selects a bearer
format type for a communication session associated with the mobile station based on the
received bearer format type information, and informas the base station of the selected
bearer format type
Still another embodiment of the present invention encompasses a system for
distributing bearer format type information. The system includes a first base station
having a first transcoder and that conveys first bearer format type information, wherein
the first bearer format type information comprises, when a first bearer format type is
assigned to a first mobile station, the assigned bearer format type and further comprises,
when the first mobile station, and the first base station mutually support a second bearer
format, the second bearer format. The system further includes a first Packet Switch
having a second transcoder and that receives the first bearer format type information from
the first base station, determines whether the first Packet Switch and one or more of the
first mobile station and the first base station mutually support a third bearer format type,
and conveys second bearer format information comprising the first bearer format type
information and, when the first Packet Switch and one or more of the first mobile station
and the first base station mutually support a third bearer format type, the third bearer
format type. The system further includes a second Packet Switch having a third
transcoder and that receives the second bearer format type information from the first base
station, determines whether the second Packet Switch and one or more of the first mobile
station, the first base station, and the first packet Switch mutually support a fourth, bearer
format type, and conveys third bearer format type information comprising the received
second bearer format type information and, when the second Packet Switch and one or
more of the first mobile station, the first base station, and the first Packet Switch mutually
support a fourth bearer format type, the fourth hearer format type. The system further
includes a second base station having a fourth transcoder and that receives the third
bearer format type information from the second Packet Switch and assigns a bearer
format to a second mobile station serviced by the second base station based on the third
bearer format type information.
The present invention may be more fully described with reference to FIGs, 1-5.
FIG. 1 is a block diagram of a wireless communication system 100 in accordance with an

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embodiment of the present invention. Communication system 100 includes a first base
station (BS) 110 that comprises a first hase transceiver station (BTS) 112 operably
coupled to a first base station controller (BSC) 120. Communication system 100 further
includes a fitst core network 140 that is upstream from, and copied to, BS 110, and in
particular to BSC 120, and that comprises a first Packet Switch 130. BS 110 provides
communication services to a first mobile station 102 via BTS 112 and further via a first
air interface 108.
Communication system 100 further includes a second base station (BS) 170 that
comprises a second base transceiver station (BTS) 172 operably coupled to a second base
station controller (BSC) 180, Communication system 100 further includes a second core
network 150 that is upstream from, and coupled to, BS 170, and in to particular DSC 1 SO.
and that comprises a second Packet Switch 160. BS 170 provides communication
services to a second MS 192 via BTS 172 and further via a second air interface 198.
Each Packet Switch 130, 160 may comprise one or more of a Media Gateway, a
3G (Third Generation) Mobile Switching Center (MSCe), and a packet voice Soft Switch
that is available from Motorola, Inc, of Schaumburg, Illinois, and that has been modified
to perform the functions described herein. Each air interface 108, 198 comprises a
forward link (not shown) having multiple communication channels, such as one or more
forward link control channels, one or more forward link traffic channels, and a forward
link paging channel, and a reverse link (not shown) having multiple communication
channels, such as one or more reverse link control channels, one or more reverse link
traffic channels, and a reverse link access channel.
Each of MSs 102 and 192, BSCs 120 and ISO, and Packet Switches 130 and 160
includes a respective processor 104, 194, 122, 182, 131, 161, such as one or more
microprossor, microcontrollers, digital signal processors (DSPs), combinations (hereof
or such other devices known to those having ordinary skill in the art. Each of MSs 102
and 192> BSCs 120 and ISO, and Packet Switches 130 and 160 further includes a
respective one or more memory devices 106, 196,124,184,132,162 associated with the
respective processor 104, 194, 122, 182, 131, 161, such as random access memory
(RAM) dynamic random access memory (DRAM), and/or read only memory (ROM) or

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equivalents thereof, that store data and programs that may be executed by the processor.
Bach of BSCs 120 and 180 and Packet Switches 130 and 160 further optionally includes a
respective transcoder 125, 186, 133,163 that is capabte of is capable of decoding voice
data packets into at least one of multiple bearer format types, such as SMV (18-893),
EVRC (1S-127), 13k-QCELP (IS-733), 8k-QCELP (IS-96C), and G.711. The one or
more memory devices 106, 196 of each of MSs 102 and 192, as well as the one or more
memory devices 124, 184,132, 162 of each of BSCs 120 and 180 and Packet Switches
130 and 160 when the BSC or Packet Switch includes a transcoder, farther stores the
bearer format types supported by the MS or associated transcoder, that is, by trancoders
126,186, 133 and 163 with respect to BSCs 120 and 180 and Packet Switches 130 and
160.
Each Packet Switch. 130,160 further includes a respective hearer format controller
135, 165 that is capable of determining a bearer format of the multiple bearer formats
possible in communication system 100 that will encode and decode voice traffic of
various bearer formata during a communication session involving MS 102. Each bearer
format controller 135, 165 includes a respective processor 136,166, such as one or more
microprocessors, microcontrollers, DSPs, combinations thereof or such other devices
known to those having ordinary skill in the art. Each bearer format controller 135, 165
further includes a respective one or more associated memory devices 137, 167, such as
RAM, DRAM, and/or ROM or equivalents thereof that maintain data and programs that
may be executed by the corresponding processor. However, in another embodiment of
the present invention each bearer format controller 135, 165 may be implemented in a
respective processor 131,161, and a respective one or more memory devices 132, 162, of
the associated Packet Switch 130,160.
First core network 140 communicates with second score network 150 via a wide
area packet transport network 142. As a result, first MS 102 is able to engage in voice
communications with second MS 192 via first air interface 108, first BS 110, first core
network 140, wide area packet transport network. 142, second core network 150, second
BS 170, and second air interface 198. Together, BSs 110 and 170, core networks 140 and.
150, and wide area packet transport network 142 are collectively referred to herein as a
communication system network.

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Communication system 100 comprises a wireless packet voice communi cation
system. In order for each MS 102,192 to engage in a voice communication with another
MS, each of BSs 110, 170, core networks 140, 150, and wide area packet transport
network 142 operates in accordance with well-known wireless telecommunications
protocols. By operating in accordance with well-known protocols, a user of an MS 102,
192 can be assured that the MS will be able to communicate with a respective serving BS
110,170 and a respective serving core network 140, 150, and establish a communication
link with a network external to the serving core network, such as core networks 150 and
140, respectively. Preferably, communication system 100 operates in accordance with the
3GPP2 and TIA/EIA (Telecommunications Industry Association/Electronic Industries
Association) IS-2001, or IOS (Inter Operability Specification), standards, which provides
a compatibility standard cdma2000 or IXEV-DO systems and wherein each
communication, channel of the multiple communication channels of each of the forward
link and the reverse link of air interfaces 108 and 198 comprises one or more orthogonal
codes, such as Walsh codes. The standard specifics wireless telecommunications system
operating protocols, including radio system parameters and call processing procedures,
However, those who are of ordinary skill in the art realize that communication system
100 may operate in accordance with any one of a variety of wireless packet-oriented voice
communication systems, such as a Global System for Mobile communication (GSM)
cmmunication system, a Time Division Multiple Access (TDMA) commmunication
system, a Frequency Division Multiple Access (FDMA) communication system, or an
Orthogonal Frequency Division Multiple Access (OFDM) communication system,
When an originating MS, such as MS 102, establishes a communication session
with BS 110, in ton establishing communication sessions with Packet Switch 130,
cnmmunication system 100 may determine one or more bearer format types, to be used
during the communication session. Further, a mobile-to-mobile communication session
may additionally- involve a terminating wireless communication network, that is, core
network 150, BS 170 and a terminating MS, such as MS 192, in regard to which
communication system 100 may further determine one or more bearer format types to be
used by the terminating wireless communication network during the communication
session. In addition, communication system 100 may determine the bearer format

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required to establish the mobile-to-mobile communication session as a transcoder free
operation (TrFO) wherein votes traffic propagates through the communication system
without being interworked, that is translated, by any network transcoder 126, 133, 163,
186. However, in order for communication system 100 to determine the one or more
bearer format types or whether to establish teh communication session as a TrFO, the
communication system; must determine the bearer format type capabilities of each MS
102, 192 engaged in the communication session and farther of each transcoder 126, 133,
163, 186 located along a voice bearer path associated with the MSs. Accordingly,
communication system 100 provides a method and apparatus for distributing information
concerning the bearer format type capabilities of each MS 102, 192 engaged in the
communication session and farther of each transcoder 126, 133,163, 186 located along a
voice bearer path associated with the communication session.
Referring now to FIGs, 2A, 2B, 2C, and 2D, a logic flow diagram 200 illustrates
steps executed by comunication system 100 in distributing information concerning the
bearer format type capabilities of each MS, auch as one or more of MSs 102 and 192,
engaged in the communication session and further of each transcoder, such as one or
more of trancoders 126, 133, 163 and 186, located along a voice bearer path associated
with the MSs In accordance with an embodiment of the present invention. Logic flow
diagram 200 begins (202) when MS 102 conveys to network 180, and in particular to BS
110 via BTS 112, and BS 110 receives (204), a request for service, that is, a request to
establish, a voice, or a voice and data, communication session with MS 192. Preferably,
the request for service comprises an Origination Message as is known in the art, which
Origination Message requests service and requires a Layer 2 acknowledgment. Equitably,
the request for service may also comprise an Page Request message and requires a Page
Response message. Unless otherwise specified herein, the functions performed herein by
each MS 102, 192 are performed by the respective processor 106, 196 the MS.
Furthermore, unless otherwise specified herein, the functions performed herein by each of
BS 110 and BS 170 are performed by a respective BSC 120, 180, and in particular a
respective processor 123, 182 of the BSC, and the functions performed by BSCs 120 and
ISO, Packet Switches 130 and 160, and bears* format controllers 135 and 165 are
respectively performed herein by processors 123, 182, 132, 162, 136, and 166.

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In response to receiving the request for service, BS 110 determines (206) whether
one or more bearer format types are supported by originating MS 102. In one
embodiment of the present invention, BS 110 may determine whether one or more bearer
format types are supported by originating MS 102 by first requesting, from the MS, the
bearer format types supported by the MS. For example, as part of the setup of the
communication session, B8 110 allocates a forword link traffic channel end a reverse link
traffic in air interface 108 and further establishes a communication link between the BS
and Packet Switch 130 for the communication session. Upon establishing the traffic
channels and communication link, BS 110 conveys to MS 102 a request for a list of
service configuration supported by MS 102. Preferably, the request is included in a
Status Request/Status Response Order. In response to receiving the request, MS 102
conveys 1O BS 110 the Service Option (SO) capabilities of the MS, which SO capabilities
intitule bearer format types supported by fee MS.
In another embodiment of the present invention, BS 110 may be informed by MS
102 of the bearer format types supported by the MS without first prompting the MS for
the bearer format types, For example, as part of the setup of the communication session,
MS 102 may convey the bearer format types supported by the MS in any one of multiple
reverse link signaling OT paging messages, such as an Origination message or an Paging
Response message, which have been formatted to include voice SOs corresponding to the
supported bearer format types.
In response to receiving one or more bearer formal types supported by MS 102,
BS 110 stores (208), in association with the MS and in the one or more memory devices
124 of BSC 120, thr one or more supported bearer formal types or associated SOs. BS
110 may farther assign (210) one of the one or more supported bearer format types to the
MS, which assigned bearer format type is also stored by BS 110 in association with the
MS and in the one or more memory devices 124 of BSC 120. However, in another
embodiment of the present invention BS 110 may determine to delay assignment of a
bearer format type to MS 102. When BS 110 assigns a supported bearer format type to
MS 102, in response to assigning the bearer format type, BS 110 conveys (212) the
assigned bearer format type to the MS. For example, BS 110 may convey the assigned
bearer format type to the MS via an SO assignment in a Service Connect Message/Service

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Response Order, MS 102 may or may not then acknowledge to BS 110 that the MS is
able to support the assigned SO or bearer format type, for example by conveying a
Service Connect Completion Message to the BS.
Based on the one or more supported bearer format types received from MS 102,
BS 110 determines the bearer format types mutually supported by each of MS (02 and
various resources under control of BS 110, such as radio traffic channels and transcoder
126 of BSC 120. BS 110 then conveys (214) to Packet Switch 130, and in particular to
bearer format controller 135, and Packet Switch 130 receives (216) from the BS, first
bearer format type information comprising the bearer format type assigned, if any, to MS
102 and any other bearer format types mutually supported by MS 102 and BS 110, with
and/or without interworking by transcoder 126, that is, with and/or without requiring
bearer translation performed by transcoder 126.
In one embodiment of the present invention the one or more, bearer format type
data fields conveyed by BS 110 to Packet Switch 130 may then be propagated in bearer
format type messages among the Network Elements located along a voice bearer path
between originating MS 102 and a terminating Public Switched Telephone Network
(PSTN) 144, The bearer format type messages comprise bearer format type data fields in
which may be embedded bearer format type capabilities of an MS engaged in the
cmmunication session and one or more other Network Elements. Each Network
Element, upon receiving a bearer format type message comprising the one or more bearer
format type data fields, may then modify the data fields based on the bearer format types
supported by a transcoder or other resources associated with the Nertwork Element
For example, in one such embodiment of the present invention, based on the first
bearer format type information received from BS 110, Packet Switch 130, and in
particular bearer format controller 135, is now informed of the bearer format types/SOs
supported by MS 102 an BS 110. Based on the bearer format types/SOs supported by
MS 102 and BS 110 and the bearer format type/SO capabilities of the Packet Switch,
beater format controller 135 selects (218) a beater format type for the communication
Session. Packet Switch 130 then informs (220) BS 110 of the selected bearer format type,
For example in order to inform BS 110 of the selected bearer format type, when the first

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bearer format type information is received by Packet Switch 130 via a bearer format type
message comprising one or more bearer format type data fields, bearer format controller
135 may modify the case or more bearer format type data fields as described below with
respect to FIG. 5 to identify the selected bearer format type. Bearer format controller 135
may that convey the modified one or more bearer format type data fields to BS 110 in a
bearer format type message Based on the selected bearer formal type identified in the
bearer format type message received from bearer format controller 135, BS 110 and MS
102 may determine (222) bearer format types to be used by their respective transcoders in
conveying bearer traffic between MS 102 and MS 192, Logic flow 200 then ends (266).
In another embodiment of the present invention, wherein MS 102 engages in a
mobile-to-mobile communication session with MS 192, in response to receiving (216) the
first bearer format type information from BS 110, Packet Switch 130 stores (224) the
received first bearer format type information in the one or more memory devices 132 of
the Packet Switch or the one or more memory devices 137 of bearer format controller 135
and conveys (326) second bearer format type information that includes the received first
bearer format type information to a Packet Switch that services terminating MS 192, that
is, second Packet Switch 160. The one or more bearer format type data fields conveyed
by BS 110 to Packet Switch 130 may then be propagated in bearer format type messages
comprising the bearer format type data fields among the Network Elements located along
a voice bearer path between originating MS 102 and terminating MS 192, that is,
Network Elements 160 and 170. As a result, the one or more bearer format type data
fields provide for a distribution, in communication system 100, of the bearer format type
capabilities of originating MS 102, terminating MS 192, and each transcoder in a voice
heater path. Based on the data, collected in the one or more bearer format type data fields,
Communication system 100 is able to determine a supportable bearer format type for the
communication session and is further able to determine whether the communication
Session can support TrFO.
FIG. 3 is a block diagram of an exemplary bearer format type message 300 that
may be used by communication system 100 to distribute in the bearer format type
capabilities of one or more of originating MS 102 and terminating MS 192 and of each
transcoder in a voice bearer path in accordance With an embodiment of the present

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invention. Bearer format type message 300 comprises multiple bearer format type data
fields 301-303. Each of BSs 110 and 170, and in particular BSCs 120 and 180, and
Packet Switches 130 and 160, may assemble a bearer format type message 300, such as
the first, second, third, fourth, and fifth bearer type message listed below, based on
instructions maintained in the respective at least one memory devices 124,184,132, and
162, of such BSs and Packet Switches. In addition, each of bearer format controllers 135
and 165 may assemble a bearer format type message 300 cased on instructions
maintained in the respective at least one memory devices 137, 167 of the bearer format
controller.
Bearer format type message 300 comprises a first bearer format type data field
301 of the multiple bearer format type data fields that informs of a bearer format type, or
SO, assigned to MS 102. En one embodiment of the present invention BS 110 may
indicate a bearer format type assigned to MS 102 by embedding, in bearer format type
data field 301, a value corresponding to the assigned bearer format type or SO, For
example, BS 110 may embed a value corresponding to 'NULL,' indicating that the MS
does not specify a bearer format type or has not been assigned a bearer format type, or
may embed a value corresponding to the assigned bearer format type, such as a value
corresponding to one of SMV, EVRC, 13k-QCELP, 8k-QCELP, and G.711. In another
embodiment of the present invention, bearer format type data field 310 may comprises a
list of bearer format types, BS 110 may then indicate a bearer format type assigned to MS
102 by tagging a bearer format type in the list. When MS 102 does not specify a bearer
format type or has not been assigned a bearer format type data type, then BS l10 does not
tag any bearer format type.
Bearer format type message 300 further comprises a second bearer format type
data field 302 of this multiple bearer format type data fields that informs of any bearer
format type, or SO, that is mutually supported by MS 102 and the BS 110, without
interworking, that is, without a need for transcoding by transcoder 126, other than the
bearer format type assigned to the MS, Similar to data field 301, in one embodiment of
the present invention, BS 110 may indicate each, bearer ibnuat type that is mutually
supported by MS 102 and BS 110 without interworking by embedding, in bearer format
type data field 302, a value corresponding to each such mutually supported bearer format

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type or SO. When BS 110 knows of no mutually supported bearer format types, the BS
may embed a value corresponding 'NULL.' Again similar to data field 301, in another
embodiment of the present invention, second bearer format type data field 302 may
comprise a list of bearer format types. BS 110 may than indicate each mutually supported
bearer format type by tagging the bearer format type, When BS 110 knows of no
Mutually supported bearer format types, the BS does not tag any bearer format type.
As a result, the bearer format types listed in the first and second bearer format
type data fields 301, 302 are 'native' to MS 102, that is, are bearer format types that the
MS can support without requring any transcoding by BS 110. Since the MS supports
each of these bearer format types, these are bearer format types that are eligible for TrFO
with respect to MS 102.
Dearer format type message 300 further comprises a third bearer format type data
field 303 of the multiple bearer format type data fields that informs of any bearer format
type, or SO, that is mutually supported by MS 102 and by a transcoder of at least one
Network Element in communication system 100, such as by transcoder 126 of BS 110,
transcoder 133 of Packet Switch 130, transcoder 163 of Packet Switch 160, and
transooder 186 of BS 170, and that requires interworking by the at least one Network
Element transcoder. That is, each bearer format type identified in third bearer format type
data field 303 is a bearer format type that is not directly supported by MS 102 but that can
be translated by the at least one Network Element to a 'native' bearer format type
supported by the MS. Each Network Element 110, 130, 160, and 170 may indicate a
bearer format type that is mutually supported by MS 102 and the Network Element, that
is, by a respective transcoder 126, 131, 163, 186 of the Network Element, with
interworking by embedding, in bearer format type data field 303, a value corresponding to
each bearer format type supported by the Network Element and not by MS 102, which
bearer format type tan be translated by the Network Element to a bearer format type
supported by the MS. When the Network Element is not capable of supporting
translation between any such bearer format types, the Network Element omits appending
beaier format values in data field 303 or alternately embeds a value corresponding
'NULL' in another embodiment of the present invention, third bearer format type data
field 303 may comprise 4 list of bearer format types. The Network Element may then

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indicate each bearer format type supported by the Network Element and not by MS 102,
which bearer format type the can be translated by the Network Element to a bearer format
type supported by the MS, by tagging the beater format type. When the Network Element
is not capable of supporting translation between any such bearer format types, the
Network Element does not tag any bearer format type.
FIG, 4 is a logic flow diagram 400 of steps executed by a BS, such as BSs 110 and
170, and in particular processors 122 and 182 of BSCs 120 and 180, in assembling a
beater format type message such as beard format type message 300 in accordance with
an embodiment of the present invention. When assembled by BS 110, message 300 may
comprise a modified version of a CM Service Request message or an Assignment
Complete message, which CM Service Request message or Assignment Complete
message is modified to include the bearer format type data fields 301-303.
Logic flow diagram 400 begins (402) when the BS, such as BS 110, determines
(404) whether the MS serviced by the BS, that is, MS 102, is assigned a bearer format
type or an associated SO. Although the assembly of beater format type message 300 is
described herein with respect to originating MS 102 and the BS servicing MS 102. that is,
BS 110) one of ordinary skill in the art realizes that bearer format type message 300 may
also be assembled by a BS, such as BS 170, servicing a terminating MS, that is, MS 192.
When BS 110 determines that MS 102 is assigned a bearer format type or an associated
SO, She BS embeds (406) a value in first bearer format type data field 301 that
corresponds to the assigned bearer format type or associated SO, or associates a tag with
the value in first bearer format type data field 301 corresponding to the assigned bearer
format type or associated SO. When BS 110 determines that MS 102 is not assigned a
bearer format type or an associated SO, the BS (408) omits tagging any bearer format
type or SO in first bearer format type data field 301 or embeds, in the data field, a value
corresponding to 'NULL.'
BS 110 then determines (410) whether the BS knows of bearer format types or
associated SOs that have not been assigned to MS 102 and that can be mutually supported
by the MS and the BS without interworking, that is, without bearer format type
translations by the BS. When BS 110 determines one or more bearer format types or

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associated 30s that are mutually supported by both the BS and MS 102 without
interworking and that have not been assigned to the MS, the BS embeds (412), in second
bearer format type data field 302, a value corresponding to each such mutually supported
beater format type or SO or associates a tag with each value in second bearer format type
data field 302 corresponding to the mutually supported bearer format type or SO. When
BS 110 is unable to determine at least one bearer format type or SO that is mutually
supported by the BS and MS 102 without interworking and that has not been assigned to
the MS, the BS (41 4) omits tagging any bearer formal type or SO in second bearer format
type data field 302 or embeds, in the data field, a value corresponding to'NULL.'
BS 110 then determines (416) whether the BS knows of bearer format types or
assoicated SOs that are mutually supported by MS 102 and the BS 110 via interworking.
That is, BS 110 determines whether it is capable of supporting one or more bearer format
types of associated SOs that is riot natively supported by MS 102 but is a bearer format
type that the BS is capable of translating to a bearer format type supported by the MS.
When BS 110 determines one or more bearer format types or associated SOs that are not
natively supported by MS 102 but is a bearer format type that the BS is capable of
translating to a bearer format type supported by the MS, the BS embeds (418), in third
bearer format type data field 303, a value corresponding to each such mutually supported
bearer format type or SO or associates a tag with each value in third bearer format type
data field 303 corresponding to the supported bearer fonnat type or SO. When BS 110 is
unable to determine a bearer format type that is not natively supported by MS 102 but is a
bearer format type that the BS is capable of translating to a bearer format type supported
by the MS, the BS (420) omits tagging any bearer format type in third bearer format type
data field 303 or embeds, in the data field, a value corresponding to 'NULL.' Logic flow
400 then ends (422).
Referring again to FIG. 2, in response to receiving (216) the first bearer fonnat
type information from BS 110, Packet Switch 130 may further determine whether any
bearer fonnat types or associated SOs not idientified in the first bearer format type
information can be supported via translation, that is, via interworking, by Packet Switch
130 to and from one or more of the bearer format types or associated SOs that are
assigned to originating MS 102 or that are mutually supported by MS 102 and serving BS

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110 without interworking. That is Packet Switch 130 further determines whether any
additional bearer format types or associated SOs can be supported via translation, that is,
via interworking, by Packet Switch 130, and in particular by transcoder 133 of the Packet
Switch, to and from one or more of the bearer format types or SOs identified in first
bearer format type data field 301 or second bearer format type data field 302. When
Packet Switch 130 determines one or more such bearer format types/SOs, Packet Switch
130 further forwards (228) such bearer format types/SOs to terminating Packet Switch
160 as part of the second bearer format type information.
When the first bearer formal type information is received by Packet Switch 130
from BS 110 via a first bearer format type message comprising bearer format type data
fields 301-303, Packet Switch 130 may inform Packet Switch 160 of the first bearer
fonnat type information, as well as any bearer fonnat types/SOs that can be supported via
interworking by Packet Switch 130, by conveying a second bearer fonnat type message
comprising a modified version of data fields 301-303. For example, the second bearer
format type message may comprise a modified version of a SIP Invite message, which
SIP Invite message has been modified to include data fields 301-303 received by, and
possibly modified by, Packet Switch 130.
In one embodiment of the present invention, Packet Switch 130 may modify data
fields 301-303 by adding, to third bearer format type data field 303, a value
corresponding to each such bearer fonnat type or SO that can be supported via translation
by Packet Switch 130 and which bearer fonnat type/SO is not identified in the first bearer
format type message. In another embodiment of the present invention, when data field
303 comprises a list of beater format types, Packet Switch 130 may modify data fields
301-303 by associating a tag with each bearer format type listed in data field 303 that
corresponds to a bearer format type or SO that can be supported via translation by Packet
Switch 130 and that is not tagged in the first bearer format type message.
As a result, the second bearer format type information conveyed by Packet Switch
130 to Packet Switch 160 informs Packet Switch 160 of a bearer format type/SO assigned
to originating MS 102, if any were so assigned, and of each bearer format type that may
be directly supported by MS 102 or that may be supported by MS 102 in conjunction with

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interworking by the transcoder 126, 133 of one or more of BS 110 and Packet Switch
130. That is, terminating Packet Switch 160 is informed of the bearer format types/SOs
that the originating side of communication system 100, that is MS 102, BS 110, and core
network 140, is capable of supporting during the communication session
In response to receiving (230) the second bearer format type information,
terminating Packet Switch 160 stores (233) the received second bearer format type
iafbrmMioii in the one or more memory devices 162 of the Packet Switch or the one or
more memory devices 167 of bearer format controller 165. Packet Switch 160 further
conveys (234) third bearer format type information that includes the second bearer format
type information to the BS serving terminating MS 192, that is, second, or terminating,
BS 170.
Similar to Packet Switch 130, Packet Switch 160 may further determine whether
any bearer format types or associated SOs not identified in the second bearer format type
information can be supported via translation, that is, via interworking, by Packet Switch
160 to and/or from the bearer format types/SOs Identified in the in the second bearer
format type information. For example, Packet Switch 160 may further determine whether
any additional hearer format types or associated SOs can be supported via translation, that
is, via interworking, by Packet Switch. 160, and in particular by transcoder 165 of the
Packet Switch, to and from the bearer format types or SOs identified in the first bearer
format type infonnation When Packet Switch 160 determines one or more such hearer
format types/SOs, Packet Switch 160 further forwards (236) such bearer format
types/SOs to BS 170 as part of the third bearer format type information.
When the second bearer format type information is received by Packet Switch
160 from Packet Switch 130 via a second bearer format type message comprising bearer
format type data fields 301-303, Packet Switch 160 may inform BS 170 of second bearer
format type information, as well as any additional bearer format types/SOs that can be
Supported via interworking by Packet Switch 130, by conveying a third bearer format type
message comprising modified version of data fields 301-303. For example, the third
bearer format type message may comprise a modified version of a Page Request message,
an Assignment Request message, or a Bearer Request message, which Page Request

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message, Assignment Request message, or Bearer Request message has been modified to
include the data fields 301-303 received by, and possibly modified by, Packet Switch 160.
In one embodiment of the present invention, Packet Switch 160 may modify data
fields 301-303 by adding, to third bearer format type data field 303, a value
corresponding to each such bearer format type or SO that can be supported via translation
by Packet Switch 160 and which bearer format type/SO is not identified in the second
bearer format type message. In another embodiment of the present invention, when data
field 303. comprises a list of bearer format types, Packet Switch 150 may modify data
fields 301-303 by associating a tag with each bearer format type listed in data field 303
that corresponds to a bearer format type or SO that can be supported via translation by
Packet Switch 160 and that is not tagged in the second bearer format type message.
In response to receiving (238), from Packet Switch 160, the third bearer format
type information, BS 170 assigns (2300) to terminating MS 192 one of the bearer format
types/SOs identified in the third bearer format type information. For example, Packet
Switch 160 may convey the third bearer format type information to BS 170 in the third
bearer format type message, which message includes bearer format type data fields 301-
303. When the bearer format type data fields 301-303 received by BS 170 include a tag
or value embedded in bearer format type data field 301 identifying a bearer format
type/SO assigned to MS 102, then BS 170 may then attempt to assign to terminating MS
192 the bearer format type/SO identified in bearer format type data field 301. When the
bearer format type data fields 301-303 received by BS 170 include one or more tags or
values embedded in bearer format type data field 302 identifying, one or more bearer
fonnat types/SOs mutually supported by MS 102 and BS 130 without requiring
interworking by BS 130, then BS 170 may then attempt to successively assign, to
terminating MS 192, each bearer fonnat type/SO identified in bearer fonnat type data
field 302 until an assignment is successful. When the bearer fonnat type data fields 301-
303 received by BS 170 include one or more tags or values embedded in bearer fonnat
type data field 303 identifying one or mote bearer fonnat types/SOs mutually supported
fay MS 102 and BS 130 and requiring interworking by one or more of BS 130 and Packet
Switch 130, then BS 170 may attempt to successively assign, to terminating MS 192,
each bearer format type/SO identified in bearer format type data field 303 and supported

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by BS 170 until an assignment is successful.
Since interworking may cause degradation in a quality of conveyed voice, it is
desirable to minimize an amount of interworking performed by communication system
100 during the communication session between MS 102 and MS 192. Optimally, no
interworking is performed by the communication system network and the communication
session is a TrFO communication session. Therefore, when bearer format types are
identified in more than one bearer format type data field of bearer format type data fields
301-303, BS 170 may first attempt to assign a bearer format type/SO identified in bearer
format type data field 301. When no bearer format type/SO is identified in bearer format
type data field 301 Of the attempted assignment is unsuccessful, BS 170 may attempt to
assign a. bearer format type/SO Identified in bearer format type data field 302. When no
bearer format type/SO is identified in either bearer formal type date field 301 or 302 or an
attempted assignment of each bearer format type/SO identified in bearer format type data
fields 30l and 302 is unsuccessful, BS 170 may assign a bearer format type/SO identified
in bearer format type data field 303.
Tn response to assigning a bearer format type/SO to MS 192, BS 170 (242) stores
the assigned bearer format type/SO, BS 170 further conveys (244) to terminating Packet
Switch 160, and in particular to bearer format controller 165, and the terminating Packet
Switch receives (246) from the BS, fourth bearer format type information comprising the
bearer format type assigned to MS 192 and any other bearer format types mutually
supported by MS 192 and BS 170, with or without interworking by transcoder 186.
Preferably, BS 170 informs Packet Switch 160 of the assigned and/or mutually supported
bearer format types/SOs by conveying to the Packet Switch a fourth bearer format type
message comprising bearer format type data.fields 301-303 and that is assembled by the
BS as described in detail above with respect to FIG. 4. For example, the fourth bearer
format type message may comprise a modified version of a Page Response message, an
Assignment Complete message, or a Bearer Response message, which Page Response
message, Assignment Complete message, or Bearer Response message has been modified
to include the bearer format type data fields 301-303 assembled by BS 170. As a result,
terminating Packet Switch 160 may now possess information concerning the bearer
format types/SOs that may be supported by the originating side of communication system

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100, that is MS 102, BS 110 and Packet Switch 130, and by the terminating side of the
network, that is, Packet Switch 160, BS 170, and MS 192.
Therefore, in one embodiment of the present invention, in response to receiving
(246) the fourth beater format type information from BS 170, terminating Packet Switch
160, and in particular bearer format cautioner 165, may select (248) a bearer format type
for the communication session involving MSs 102 and 152, Packet Switch 160 then
informs (250) the originating side of communication system 100, and in particular Packet
Switch 130, of the selected bearer format type. Based on the selected bearer format type,
each of Packet Switch 1.30, BS 110, and MS 102 may determine (252) bearer format
types to be used by their respective transcoders in conveying bearer traffic between MS
102 and MS 192 and logic flow 200 then fends (266).
In one embodiment of the present invention, Packet Switch. 160 may informs
Packet Switch 130 of the selected bearer type format by modifying the bearer type data
fields 301 -303 received via a fourth bearer format type message by Packet Switch 160
form BS 170 and conveying a bearer format type message comprising the modified data
fields to Packet Switch. 130. For example, the bearer format type message may comprise
a modified version of an SIP_ 183 message arm SIP_Update message, which SIP_183
message or SIP_Update message has been modified to include the data fields 301-303
received by Packet Switch 160 from BS 170 and further possibly modified, by the Packet
Switch, Packet Switch 130 may then propagate these modified versions of data fields
301-303 to BS 110 and, based on the modified versions of the data fields, each of Packet
Switch 130 and BS 110 may determine bearer format types to be used by their respective
transcoder 133, 126 or whether to remove the transcoder from the bear path of the
communication session. BS 110 may further determine a bearer format type to be used
by MS 110 and assign to the MS the determined bearer format type.
For example, FIG- 5 is a logic flow diagram 500 of steps executed by Paeket
Switch. 160 in. modifying bearer type data fields 301-303 of bearer format type message
300 in accordance with an embodiment of the present invention. Logic flow diagram 500
begins (502) when Packet Switch 160 selects (504) a bearer format type/SO for the
communication session from among one or more hearer format types/SOs identified as

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bearer format types/SOs capable of being supported by the communication system 100,
that is, from one of bearer type data fields 301-303. When the selected bearer format
type/SO is a beater format type/SO identified as being assigned to terminating MS 192,
that is, a bearer format type/SQ identified (506) in bearer format type data field 301,
terminating Packet Switch 160 deletes (508) all tags in bearer format type data fields 302
and 303 or deletes all values embedded in fields 302 and 303 and embeds in each of
fields 302 and 303 a value corresponding to 'NULL,' Logic flow 500 then ends (522).
When the selected bearer format type/SO is a bearer format type/SO identified as
being mutually supported by terminating MS 192 and terminating BS 170 without
interworking that is, a bearer format type/SO identified (510) in bearer format type data
field 302, terminating Packet Switch 160 deletes (512) all tags in bearer format type data
field 302 associated with a bearer format type/SO other than the selected bearer fcunat
type/SO or deletes all values embedded in field 302 by BS 170 other than the value
associated with the selected bearer format type/SO. Terminating Packet Switch 160
further deletes (514) all tags in bearer format type data fields 301 and 303 or deletes all
values embedded in fields 301 and 303 and embeds in each of fields 301 and 303 a value
corresponding to 'NULL1 Logic flow 500 then ends (522).
When the selected bearer format type/SO is a bearer format type/SO identified as
being mutually supported by terminating MS 192 and BS 170 with interwoddng, That is, a
bearer format type/SO identified (516) in bearer format type data field 303, terminating
Packet Switch 160 deletes (518) all tags in bearear format type data field 303 associated
with a bearer format type/SO other than the selected bearer format typs/SO or deletes all
values embedded in field 303 other than the value associated with the selected bearer
format type/SO, Terminating Packet Switch 160 further deletes (520) all tags in bearer
format type data fields 301 and 302 or deletes all values embedded in fields 301 and 302
and embeds in each of fields 301 and 302 a value corresponding to 'NULL.' Logic flow
500 then ends (522).
Referring again to FIG, 2, in another embodiment of the present invention, in
response to receiving (246) the fourth bearer format type information from BS 170,
terminating Packet Switch 160 may forward fifth bearer format type information to

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Packet Switch 130 comprising the fourth bearer format type information received from
BS 170. That is, in response to receiving the fourth bearer formal; type information from
BS 170, Packet Switch 160 may convey (254), to originating Packet Switch 130, Nearer
format information concerning the bearer format type assigned to terminating MS 192,
bearer formal types mutually supported by MS 192 and serving BS 170 without
interworking, and bearer format types mutually supported by terminating MS 192 and BS
170 with interworking.
In addition, Packet Switch 160 may determine, and convey (256) to Packet Switch
130 as part of the fifth bearer format type information, any bearer format types or
associated SOs that can be supported via interworking by Packet Switch. 160, and in
particular by transcoder 163 of the Packet Switch, to and/or from the bearer format types
or associated SOs identified in the fourth bearer format type information.
When the fourth bearer format type information is received by Packet Switch 160
from BS 170 via a fourth bearer format type message comprising bearer format type data
fields 301-303, Packet Switch 160 may convey the fifth bearer format type information to
Packet Switch 130 via a fifth bearer format type message comprising modified version of
data fields 301-303 received from BS 170, Again, by way of example, the fifth bearer
format type message may comprise a modified version of an SIP_183 message or an
SIP_Update message, which SIP_ 183 message or SIP_Update message has been modified
to include the data fields 301-303 received by Packet Switch 160 from BS 170 and father
possibly modified by Packet Switch 160.
In the fifth bearer format type message, Packet Switch 160 may identify any
bearer format types/SOs that can be supported via interworking by Packet Switch 160 and
that are not identified in the fourth bearer format type message by modifying the third
bearer format type data field 303 as is described in detail above. That is, in one
embodiment of the present invention, Packet Switch 160 may modify data field 303 by
adding to the data field a value corresponding to each such beater format type or SO that
can be supported via translation by Packet Switch 160. In another embodiment of the
present invention; when data field 303 comprises a list of bearer format types, Packet
Switch 160 may modify the data field by associating a tag with each bearer format type

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listed in data field 303 that corresponds to a bearer format type or SO that can be
supported via translation by Packet Switch 160.
In response to receiving (258) the fifth bearer format type information from
terminating Packet Switch 160, originating Packet Switch 130, and in particular bearer
format controller 135, may select (2320) a bearer format type for the communication
session involving MSs 102 and 192- Packet Switch 130 then informs (362) BS 110 of the
selected bearer format type. Based on the selected bearer format type, BS 110 and MS
102 may determine (264) bearer format types to be used by their respective transcoders in
conveying bearer traffic between MS 102 and MS 192 and logic flow 200 then ends
(266).
Similar to the process described above with respect to Packet Switch 160 selecting
a bearer format type and informing the originating side of communication system 100 of
the selected bearer format type, Packet Switch 130 may inform BS 110 of the selected
beaier type format by modifying the bearer type data fields 301-303 received by Packet
Switch 130 via the fifth bearer format type message pursuant to the method depicted in
logic flow diagram 500. Packet Switch. 130 may then convey a message comprising the
modified data fields to BS 110, Based on the modified versions of the data fields, BS 110
may determine bearer format types to be used by transcoder 126 or whether to remove the
transcoder from the bear path of the communication session. BS 110 may further
determine a bearer format type to be used by MS 110 and then assign, or alternatively
reassign, to the MS the determined bearer format type.
Again, since it is desirable to minimize an amount of interworking and bearer
format/SO reassignments performed by communication system 100 during the
communication session between MS 102 and MS 19, when Packet Switch. 130, 160
selects a bearer format type/SO for use in the communication session, the Packet Switch
may first select a bearer format type/SO identified, in bearer format type data field 301.
When no bearer format type/SO is identified in bearer format type data field 301 or the
attempted assignment is unsuccessful, the Packet Switch 130, 160 may then select a
bearer format type/SO identified in bearer format type data field 302. When no bearer
format type/SO is identified in either bearer format type data field 301 or 302 or an

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attempted assignment of each bearer format type/30 identified in. bearer format type data
fields 301 and 302 Is unsuccessful, the Packet Switch 130, 160 may then select a bearer
format type/SO identified in bearer format type data field 303.
By providing for a distribution of bearer format type information among one or
more Network Elements 110, 130, 160, and 170 located along a bearer path of a
communication session, communication system 100 facilitates a selection of a bearer
format type for the communication session. The bearer format type information informs
of bearer format types supported by one or more MSs engaging in the communication
session and further of Network Elements capable of translating bearer formats during the
communication session, in one embodiment of the present invention, the bearer format
types are conveyed in bearer format type data fields 301-303 of bearer format type
messages 300, which data fields may be modified by each Network Element 110, 130,
160, and 170 in order to identify the bearer format type capabilities of the Network
Element. A bearer format controller 135,165 may then select a bearer format type for the
communication session based on bearer format types identified in the bearer format type
messages. The bearer format controller 135,165 may then inform one or more Network;
Elements of the selected bearer format type by modifying the bearer format type data
fields of a bearer format type message received by me controller and conveying the
modified bearer format type data fields to the Network Elements.
While the present invention has been particularly shown and described with
reference to particular embodiments thereof, it will be understood by those skilled in "the
art that various changes may be made and equivalents substituted for elements thereof
without departing from the scope of the Invention as set forth in the claims below.
Accordingly, the specification and figures are to be regarded in an illustrative rather then
a restrictive sense, and all such changes and substitutions are intended to be included
within the scope of the present invention.
Benefits, other advantages, and solutions to problems have been described above
with regard to specific embodiments. However, the benefits, advantages, solutions to
problems, and any elements) that may cause any benefit, advantage, or solution to occur
or become more pronounced are not to be construed as a critical, required, or essential

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feature or element of any or all the claims. As used herein, the terms "comprises,"
"comprising," or any variation thereof, ate intended to cover a non-exclusive inclusion,
such that a process, method, article, or apparatus that comprises a list of elements does
not include only those dements but may include other elements not expressly listed or
inherent to such process, method, article, or apparatus. It is further understood that the use
of relational terms if any, such as first and second, top and bottom, and the like are used
solely to distinguish one entity or action from another entity or action without necessarily
requiring or implying any actual such relationship or order between such entities or
actions.

WO 2005/057799 PCT/US2004/040809
What is claimed is:
1. A method for providing bearer format type capabilities in a cellular
communication system, the method comprising:
assembling a message comprising bearer format type information, wherein, the
bearer format type information comprises, when a first bearer format type is assigned to a
mobile station, the assigned bearer format type, and further comprises, when the mobile
station and a Network Element serving the mobile station mutually support a second
bearer format the second bearer format; and
conveying the assembled message,
2. The method of claim 1, wherein the second beater format type comprises at least a
second bearer format type and wherein the at feast a second bearer format type comprises
at least one of a second bearer format type mutually supported by the mobile station and
the Network Element without interworking by a transcoder and a third bearer format type
mutually supported by the mobile station and the associated Network Element with
interworking by the transcoder.
3. The method of claim 1, further comprising:
receiving the bearer format type information; and
selecting a bearer format type for a communication session associated with the
mobile station based on the received bearer format type information, and
conveying a message informing of the selected bearer format type.
4. The method of claim 3, wherein the bearer format information is conveyed in a
bearer format type message comprising a plurality of bearer format data fields and
wherein conveying a message informing of the selected bearer format type comprises:
modifying the bearer format type data fields to produce modified bearer format
data fields, wherein the modified bearer format type data fields identify the selected
bearer format type; and
conveying the modified bearer format data fields.

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5. A method for providing bearer format type capabilities in a cellular
communication system, the method comprising:
receiving bearer format type information comprising at least one of a first hearer
format type assigned to a moblle station and a second bearer format type mutually
supported by the mobile station and a base station serving the mobile station; and
conveying the received bearer format type information to a Network. Element
other than the base station.
6. The method of claim 5, wherein the Network Element other than the base station
comprises a first Network Element and wherein receiving comprises receiving bearer
format type information comprising at least one of a first bearer format type assigned to
the mobile station, a second beater fonnat type mutually supported by the mobile station
and a base station serving the mobile station, and a third bearer format type mutually
supported by the mobile station and one or more of the base station and a second Network
Element other than the base station.
7: The method of claim 6, further comprising:
determining whether a third Network Element other than the base station and one
or more of the mobile station, the base station, and the second Network Element mutually
support a fourth bearer format type; and
In response to determining that the third Network Element and one or more of the
mobile station, the base station, and the second Network Element mutually support a
fourth bearer format type, conveying the fourth bearer format type to the first Network
Element.
8, A method for providing bearer format type capabilities in a cellular
communication system, the method comprising;
rceiving bearer formal type information comprising at least one of a first bearer
format type assigned to a first mobile station and a second bearer format type mutually
supported by the first mobile station and a base station serving the first mobile station;
and

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assigning a bearer format type to a second mobile station based on the received
bearer format type information.
9. The method of claim 8, further comprising conveying a message informing of the
bearer format type assigned to the second mobile Station and of any other bearer format
types mutually supported by the base station and the second mobile station.
10. A method for providing bearer format type capabilities in a cellular
communication system, the method comprising assembling a message comprising a first
data field identifying a bearer format type assigned to a mobile Station and at least a
second data field identifying a bearer format mutually supported by the mobile station and
abase station serving the mobile station.
11. The method of claim 10, wherein the at least a second data field comprises a
second data field identifying a bearer format mutually supported by the mobile station and
a. base station without interworking by the base station and a third data field identifying a
bearer format mutually supported by the mobile station and one or more of a base station
and a Network Element other than the base station with interworking by each of the one
or more of the base station and the Network Element
12. A method for providing bearer format type capabilities in a cellular
communication system, the method comprising:
conveying first beater format type information, wherein the first bearer format
type information comprises, when a first bearer format type is assigned to a first mobile
station, the assigned bearer format type and further comprises, when the first mobile
station and a first base station mutually support a second bearer format, the second bearer
format;
receiving the first bearer format type information from the first base station;
in response to receiving the first bearer format type information, determining
whether a first Network Element other than the first base station and one or more of the
first mobile station and the first base station mutually support a third bearer format type;

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in response to receiving the first bearer format type information, conveying
second bearer format information comprising the first bearer format type information and,
when the first Network Element and one or more of the first mobile station and the first
base station mutually support a third bearer format type, the third bearer format type;
receiving the second bearer format type information;
in response to receiving the second bearer format type information, determining
whether a second Network Element other than the first base station and one or more of
the first mobile station, the first base station, and the first Network Element mutually
support a fourth bearer format type;
in response to receiving the second bearer format type information, conveying
third beaier format type information comprising the received second bearer format type
information and, when the second Network Element and one or more of the first mobile
station, the first base station, and the first Network Element mutually support a fourth
bearer format type, the fourth bearer format type;
receiving the third bearer format type information; and
in response to receiving the second bearer format type information, assigning a
bearer formal to a second mobile station based on the third bearer format type
information.
13 . The method of claim 12, wherein each bearer format type information of the first,
second, and third bearer format type information comprises a bearer format type message
having a plurality of bearer format type data fields and wherein each plurality of bearer
format type data fields of each bearer format type message comprises one of the plurality
of beaier format type data fields of the preceding bearer format type message or a
modified version of the plurality of bearer format type data fields of the proceding bearer
format type message.
14. The method of claim 12, further comprising:
conveying fourth bearer format type information to the second Network Element,
wherein the fourth, bearer format type information comprises the bearer format assigned
to the second mobile, station and, when the second mobile station and the second base

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34
station mutually support a bearer format other than the assigned bearer format, the other
bearer format;
receiving the fourth bearer format type information and
based on the fourth bearer format type information, selecting a bearer format type
for a communication session involving the first mobile station and the second mobile
station.
15. The method of claim 12, further comprising:
conveying fourth bearer format type information to the second Network Element,
wherein the fourth bearer format type information comprises the bearer format assigned
to the second mobile station find, when the second mobile station and the second base
station mutually support a bearer format other than the assigned bearer format, the other
bearer format;
conveying fifth bearer format type information to the first Network Element,
wherein the fifth bearer format type information comprises the fourth bearer format type
information and further comprises any bearer format types that are mutually supported by
the second Network Element and one or more of the second mobile station and a base
station serving the second mobile station and are not identified by the fourth bearer
format type information; and
receiving the fifth bearer format type information and
based on the fifth bearer format type information, selecting a bearer format type
for a communication session involving the first mobile station and the second mobile
station.
16. A base station controller that assembles a message comprising bearer format type
information, wherein the bearer format type information comprises, when a first bearer
format type is assigned to a mobile station, the assigned bearer format type, and further
comprises, when the mobile station and a Network Element serving the mobile station
mutually support a second bearer format, the second bearer format, and conveys the
assembled message.

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17 . The base station controller of claim 16, wherein the base station, controller assigns
the first bearer format type by receiving, from the mobile station, one or more bearer
format types supported by the mobile station and assigning to the mobile station a bearer
format type of the one or mors bearer format types received from the mobile station.
18. The base station controller of claim 16, wherein the second bearer format type
comprises at least a second bearer format type and wherein, the at least a Second bearer
format type comprises at least one of a second bearer format type mutually supported by
the mobile station and the associated Network Element without interwotking by the
trancecoder and a third bearer format type mutually supported by the mobile station and
the associated Network Element with interworking by the transcoder.
19. A Packet Switch comprising.
at least one memory device that maintains at least one bearer format type
supported by an associated transcoder; and
a processor coupled to the at least one memory device that receives bearer format
type information comprising at least one of a first bearer format type assigned to a mobile
station and a second bearer format type mutually supported by the mobile station and a
base station serving the mobile station and conveys the received bearer format type
information to another Network Element.
20. The Packet Switch of claim 19, wherein, the bearer format type information
received by the processor further comprises a. third hearer format type mutually supported
by the mobile station and one or more of the base station and a Network Element
interposed between the base station and the Packet Switch.
21. The Packet Switch of claim 20, wherein the processor determines whether the
Packet Switch and one or more of the mobile station, the base station, and the Network
Element interposed between the base station and the Packet Switch mutually support a
fourth bearer format type and, in response to determining that the Packet Switch and one
or more of the mobile station, the base station, and the Network Element interposed

WO 2005/057799 PCT/US2004/040809
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between the base station and the Packet Switch mutually support a fourth bearer format
type, conveys the fourth bearer format type to an another Network Element.
22. A base station controller that receives bearer format type information comprising
at least one of a first bearer format type assigned to a first mobile station and a second
beater format type mutually supported by the first mobile station and a base station
serving the first mobile station and that assigns a bearer format type to a second mobile
station based on the received bearer format type information
23. The base station controller of claim 22, wherein the bearer format type
information received by the base station controller farther comprises a third bearer format
type mutually supported by the mobile station and one or more of the base station and a
Packet Switch.
24. The base station controller of claim 22, wherein the base station controller further
conveys a message to a Network Element informing of the bearer format type assigned to
the second mobile station and of any other bearer format types mutually supported by the
base station controller and the second mobile station.
25. A system for distributing bearer format type information comprising:
a base station that comprises a first transcoder and thai conveys a message
comprising bearer format type information, wherein the bearer fomat type information
comprises, when a first bearer format type is assigned to a mobile station, the assigned
bearer format type, and further comprises, when the mobile station and the base station
mutually support a second bearer format, the second bearer format; and
a bearer format controller that receives the bearer format type information from
the base station, selects a bearer format type for a communication session associated with
the mobile station based on the received bearer formal type information, and informs the
base station of the selected bearer format type.
26. The system, of claim 25, wherein the base station further assigns the first bearer
format type to the mobile station.

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27. The system of claim 25, wherein the bearer format in is conveyed by the
base station in a bearer format type message comprising a plurality of bearer format type
data fields and wherein the bearer format controller informs the base station of the
selected beater format information, by modifying the bearer format type data fields to
produce modified bearer format data fields, wherein the modified bearer format type data
fields identify the selected bearer format type, and conveying the modified bearer format
type data fields to the base station.
28. A system for distributing bearer format type information comprising;
a first base station that comprises a first transcoder and that conveys first bearer
format type information, wherein the first bearer format type information comprises,
when E first bearer format type is assigned to a first mobile station, the assigned bearer
format type and further comprises, when the first mobile station and the first base station
mutually support a second bearer format, the second bearer format;
a first Packet Switch that comprises a second transcoder and that receives the first
bearer format type information from the first base station, determines whether the first
Packet Switch and one or more of the first mobile station and the first base station
mutually support a third bearer format type, and conveys second bearer format
information comprising the first bearer format type information and, when the first Packet
Switch and one or more of the first mobile station and the first base station mutually
support a third bearer format type, the third bearer fonnat type;
a second Packet Switch that comprises a third transcoder and that receives the
second bearer format type information from the first base station, determines whether the
second Packet Switch and one or more of the first mobile station, the first base station,
and the first Packet Switch mutually support a fourth bearer format type, and conveys
third bearer fonnat type information comprising the received second bearer fonnat type
information and, when the second Packet Switch and one or more of the first mobile
station, the first base station, and the first Packet Switch mutually support a fourth bearer
format type, the fourth bearer format type; and
a second base station that comprises a fourth transcoder and that receives ths third
bearer format type information from the second Packet Switch and assigns a bearer

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format to a second mobile station serviced by the second base station based on the third
bearer format type information,
29. The system of claim 28, wherein the first base station further assigns the first
bearer format to the first mobile station.
30. The system of claim 28, wherein each bearer format type information of the first,
second, and third bearer format type information comprises a bearer format type message
having a plurality of bearer format type data fields and wherein each plurality off bearer
format type data fields of each bearer format type message comprises one of the plurality
of bearer format type data fields of the preceding bearer format type message or a
modified version of the plurality of bearer format type data fields of the preceding bearer
format type message.
31. The system of claim 28, wherein the second base station conveys fourth bearer
format type information to the second Packet Switch, wherein the fourth bearer format
type information comprises the bearer format assigned to the second mobile station and,
when the second mobile station and the second base station mutually support a bearer
format other than the assigned bearer format, the other bearer format, and wherein the
second Packet Switch receives the fourth bearer format type information and, based on
the fourth bearer fbnnat type information, selects a bearer format type for a
communication session involving the first mobile station and the second mobile station.
32. The system of claim 28, wherein the second base station conveys fourth bearer
format type information to the second Packet Switch, wherein the fourth bearer format
type Information comprises the bearer format assigned to the second mobile station and,
when the second mobile station and the second base station mutually support a bearer
format other than the assigned bearer format, the other bearer format, wherein the second
packet switch conveys fifth bearer format type information to the first packet switch,
wherein the fifth bearer format type information comprises the fourth bearer format type
information and further comprises any bearer format types that are mutually supported by
the second packet switch and one or more of the second mobile station and the second

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base station and are not identified by the fourth bearer format type information, and
wherein the first Packet Switch receives the fifth bearer format type information and,
based on the fifth bearer format type information, selects a bearer format type for a
communication session involving the first mobile station and the second mobile station.

A communication system (100) provides for a distribution of bearer format type information among Network Ele-
ments (110 ,130, 160, 170) located along a bearer path of a commumcatation seasion, thereby faclitating a selection of a bearer format
type for the communication session. The bearer format type information informs of bearer format types supported by each of the
Network elements. In one embodiment of the present invetion, the bearer from types are conveyed in bearer format type data
fields (301-303) of bearer format type massage (300), which data fields may be modified by each Network Element in order to
identify the bearer format type capabilities of the Network Element.

Documents:

01454-kolnp-2005-abstract.pdf

01454-kolnp-2005-claims.pdf

01454-kolnp-2005-description complete.pdf

01454-kolnp-2005-drawings.pdf

01454-kolnp-2005-form 1.pdf

01454-kolnp-2005-form 3.pdf

01454-kolnp-2005-form 5.pdf

01454-kolnp-2005-international publication.pdf

1454-KOLNP-2005-(05-12-2011)-CORRESPONDENCE.pdf

1454-KOLNP-2005-(05-12-2011)-PA.pdf

1454-KOLNP-2005-(28-03-2012)-ASSIGNMENT.pdf

1454-KOLNP-2005-(28-03-2012)-CERTIFIED COPIES(OTHER COUNTRIES).pdf

1454-KOLNP-2005-(28-03-2012)-CORRESPONDENCE.pdf

1454-KOLNP-2005-(28-03-2012)-FORM-16.pdf

1454-KOLNP-2005-(28-03-2012)-PA-CERTIFIED COPIES.pdf

1454-KOLNP-2005-FORM-27.pdf

abstract-01454-kolnp-2005.jpg


Patent Number 239175
Indian Patent Application Number 1454/KOLNP/2005
PG Journal Number 11/2010
Publication Date 12-Mar-2010
Grant Date 09-Mar-2010
Date of Filing 26-Jul-2005
Name of Patentee MOTOROLA INC.
Applicant Address 1303 EAST ALGONQUIN ROAD, SCHAUMBURG, IL
Inventors:
# Inventor's Name Inventor's Address
1 MILTON LEWIS J. 1015 EDGEBROOK LANE, GLENCOE, ILLINOIS 60022
2 SCRIBANO GINO A. 40W060 EMILY DICKINSON LANE, ST. CHARLES, ILLINOIS 60175
PCT International Classification Number H04B
PCT International Application Number PCT/US2004/040809
PCT International Filing date 2004-12-07
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/527,949 2003-12-08 U.S.A.
2 10/899,292 2004-07-26 U.S.A.