Note: Descriptions are shown in the official language in which they were submitted.
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SYSTEM AND METHOD FOR PROVIDING
MOBILE SWITCHING AND MULTI-PAR~'Y SERVICES OVER A
PACKET-SWITCHED NETWORK
PRIORITY STATEMENT UNDER 35 U.S.C ~11!9{e) & 37 C.F.R. ~1.78
This nonprovisional application claims priorit,~r based upon the following
prior
U.S. provisional patent application entitled: "Syste;m and Method for
Providing
Mobile Stations in a Radio Telecommunications Network with Multimedia Services
over Packet-Based Networks," Ser. No. 60/110,811 (Attorney Docket Number 1000-
0136), filed December 3, 1998, in the names of Hung Tran, Kim Vo, Bartosz
Balazinski, Jean-Francois Bertrand, Laura Hernande::, and Suhail Hasan.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application discloses subj ect matter related to the subject matter
disclosed
in the following co-assigned patent applications: (1) "System and Method for
Providing Wireless Telephony over a Packet-Switched Network," filed October
26,
1999, Ser. No. (Attorney Docket Number 1000-144), in the names of Kim
Vo, George Foti, Hung Tran, Jean-Francois Bertrand, Bartosz Balazinski,
Francis
Lupien, Zeng-Jun Xiang, and Yang Lu; (2) "System and Method for Mobile
Terminal
Registration in an Integrated Wireless Packet-Switched Network," filed October
26,
1999, Ser. No. (Attorney Docket Number 1000-154), in the names of
Hung Tran, Laura Hernandez, Jean-Francois Bertrand, and Bartosz Balazinski.
BACKGROUND OF THE INVENTION
Technical Field of the Invention
The present invention relates to telecommunication systems and, more
particularly, to a system and method for providing mobile switching and mufti-
party
services over a packet-switched network such as, for example, a network using
the
Internet Protocol (IP). '
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I~escn~ of Related Art
Coupled with the phenomenal growth in p~opulari'y of the Internet, there has
been a tremendous interest in using packet-switched network infi'astructutes
(e-g.,
chose based on IP addressing) ass a replacement for the existing circuit-
switched
network infrastructures used in today's telephony. From the fretwork
operators'
perspective, the inherent uaffic aggregation in paclket-switched
infrasuuctures allows
for a reduction in the cast of transmission and the infrastructure cost per
end-user.
Ultimately, such cast reductions enable the network operators to pass on the
concomitant cost savings to the end-users.
~e existing Voice-over-IP (VoIP) net'vorks implement communications
infrastructures chat are typically based on mui'tiple protocols which include,
for
example, the well-knowan H.323 protocol. These: protocols are primarily
ot7ented to
operating with fixed-neT~'ork-based telecommunications protocols and arc
designed
to provide such services as call control, et cexer'~~, for wireline
subscribers. Cutient
VoIP systems, accordingly, cannot be used advarvtageou.sly in wireless
environrnenis,
although some VoIP systems may support rudimentary location managem~t
services.
There exist several inadequacies in the Plain CJId Cellular System (POCS) with
respect to supposing 1P-based infrastructures and seraices. Also, there exist
deficiencies and shortcomings in the existing 1P-based VoIP systems in Germs
of
24 supportingwireless access technology such as for example, ANSI-136, Global
System
for Mobile communications (GSIVI],1S-95, et cetera. Some pf the more
slgtuftcant of
these inadequacies and shortcomings ate sumrnati2ed below.
First, cunentPOCS systems and technology infrastructures are not compatible
with communications infrastructures as reqr.iired by the Vole standards. The
25 operation, maintenance, and the connection management required by the
tra~~ional
ppCS systems ate based on switched physical hunk copnections. These mechanisms
ue noG compatible with the packet switch's glrouttng mechanisms such as, e-g.,
Domain Name System (DNS), Dynamic Host Configuration Protocol (DHCP), etc.
required far managing devicclh4st addressing and configiuation.
3Q InGatnpatibilities also exist between '.POCS protocols atad communications
protocols of the existing vow applications. 'The POCS sY~et~ cannot support a
Plain
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Old Telephone System (POTS) or Integrated Services Digital Network (ISDN)
client
in the Internet context. The Internet "client" is typiically required to
handle Internet-
based protocols such as, e.g., Real-time Transfer Protocol (RTP), Resource
Reservation Protocol (RSVP), etc. which are not in the definition or domain of
the
POCS systems.
Another important disparity which should b~e noted is that the POCS signaling
and user data planes use distinct physical transport and network facilities,
whereas the
same physical network facilities are used to route signaling and user data
information
in the Internet domain.
With respect to the inadequacies of the existing VoIP systems, it should be
appreciated that current VoIP clients and infrastructiare can handle neither
the wireless
access-side technology nor the basic network-side functional signaling plane
which
enables mobility management, authentication/security, service definition,
service
mitigation and execution, et cetera. Clearly, the provision of such
advancements in
the POCS as Wireless Intelligent Network (WIN) services, can onlymagnify these
and
other disparities and incompatibilities between the POCS and VoIP
infrastructures.
Based on the foregoing, it is apparent that i:n order to address these and
other
problems of the current technologies set forth above, what is needed is a
seamless
integration between the existing POCS and VoIP infrastructures so that the
numerous
advantages, known and hitherto unknown, of packet-based networks may be
realized
within the context of wireless telecommunication;>. However, as those of
ordinary
skill in the art should readily appreciate, critical to implementing mobile
network
infrastructures within a VoIP system is providing end-user switching services
on an
iP-based core network in an economical way.
In addition, it should be further appreciated that in an integrated network
that
supports both mobile stations and lP terminals, it would be very advantageous
if the
IP entity that facilitates mufti-party services such as, e.g., a three-party
conference, in
accordance with a current protocol, e.g., the H.323 standard, can still be
used for such
services regardless of the access. However, it is well-known that the current
procedures for setting up a three-party corrfer~nce; using the H.323 protocol
do not
support call enquiry, call waiting, or three-party conferencing as defined by
the mobile
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communicaiiotis standard ANSI-53 or certain proprietary flash messaging
schemes_
Thus, it would be of significant benefit to provide a system arid method for
supporting
the ANSI-~3 or proprietary flash messaging within the context of art
irstegtrated VoIP
system.
SUMMARY OF THE INVENTION
In one aspeet, the present invention is dir~:cted to an integrated wireless
packet-
switched network for providing telecommunications services to a mobile
subscriber.
The network co;nprises an IP-based network portion for u'ansporCing
co~tuttication
7 0 traffic relating to the mobile subscriber. A radio network controller is
provided for
controlling radio access for the mobile subscriber. A gateway is disposed
between the
packet-switched network (ll'-based) portiotn and the radio network controller.
Further,
the gateway includes means for switching the c:omrnunication traffic relating
to the
mobile subscribez.
The interface between the gateway and radio network controller includes a
first
protocol translator for converting Transaction Capability Application Part
(TCAF)
messaging into IP messaging and a second protocol translator for convet; ring
lrttegrated
Services Digital Network (ISpl~ User Part (1;SUP) messaging into Primary Raze
Interface (PRI) messaging. In some exemplar5r erttbodiments, either or both.
of the
translators may be integrated within the IP gatemay.
In another aspect, the present invention its directed to a method of
registering
a mobile terminal in an integrated wireless pads:et-switched network which
anclndes
a cellular nehyork portion and a packet-swil~ched network portion. The
cellular
network portion comprises a serving radio >netlvor3c controller (RNC) for
pmvzding
~5 wdio access services for the mobile terminal. 'j~e packet-switched network
portion
includes a gatekeeper and a gateway, wherein the gateway comprises an IP stack
for
switching cellular traffic related to the mobile: terminal- The method begins
by
determining, in the serving RNC, that the mobilu° tertrtinal is located
in a service area
associated with the seining ~tNC. Responsive to the determining step, azs
Invoke
message is sent from the serving RNC to the gateway, wherein a Registration
>:,Tpdaie
signal is encapsulated in ibe Invoke message. I1'pon receiving the Invoke
message, a
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Registration Request message is then sent from the gateway to the gatekeeper,
the
Registration Request message including a ternainalAlias parameter. Responsive
thereto, a Registration Confirm message is sent from the gatekeeper to the
gateway
if the mobile terminal is successfully registered at the gatekeeper.
Otherwise, a
Registration Reject message is sent from the gatekeeper to the gateway.
Thereafter,
responsive to receiving either the Registration Confirm message or the
Registration
Reject message, a registration status of the mobile terminal is reported via a
Return
Result message sent by the gateway to the RNC.
in a further aspect, the present invention is related to a method of de-
registering
a mobile terminal in an integrated wireless pacl~;et-switched network system
which
includes a cellular network portion and a packet-switched network portion. The
cellular and packet-switched network portions include components as set forth
above.
The method begins by first determining, in the serving RNC, that the mobile
terminal
located in a service area associated with the serving RNC has powered down.
1 S Responsive to the determining step, an Invoke message is sent from the
serving RNC
to the gateway, wherein a Registration Update signal is encapsulated in the
Invoke
message. Upon receiving the Invoke message, a~z Unregistration Request message
is
sent from the gateway to the gatekeeper, the Unre~;istration Request message
including
an endpointAIias parameter. Responsive thereto, an Unregistration Confirm
message
is sent from the gatekeeper to the gateway if the mobile terminal is
successfully
unregistered at the gatekeeper. Otherwise, an Unregistration Reject message is
sent
from the gatekeeper to the gateway. Subsequent3!y, responsive to receiving one
ofthe
Unregistration Confirm and Unregistration Reject: messages, a registration
status ofthe
mobile terminal is reported via a Return Result nnessage sent from the gateway
to the
RNC.
In a still further aspect, the present invention is directed to an integrated
wireless packet-switched network having a wireless portion and an Internet
Protocol
(IP) portion. The IP portion preferably includes a gateway for interfacing
with the
wireless portion. The network system comprises a radio network controller for
providing radio access services to a mobile~ubscriber. The gateway includes
means
for switching communication traffic relating to 'the mobile subscriber. The
network
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syste:Gn further inc hides one or more protocol ttar~slators disposed between
the gateway
and the radio network controller.
In yet another aspect, the present invent~,on prAVides an integrated Voice
over
IP (VoIP) network that is capable of supporting tnulti-pat~tyse~viees
involving ANSI-
53 messaging or proprietary flash messaging. The V oiP network preferably
comprises
a radio network controller that provides radio access services to one or more
mobile
subscribers. A gateway is operably coupled to the radio network controller for
combining a packet-swliched portion and a circuit-switched cellular portion of
the
integated VoIP network. A Multipoint Control Unit (MC1.>] for setting up
inulii-pity
IO services is wnnected to d1e packtt-switched potion. A flash proxy agent is
disposed
between the MCU and the gateway for ma~Pping ANSI-53 or proprietary #lash
messages relating to the rr~ulti-party services into messages compatible with
the MCU.
In alicmative embodiments, the flash proxy agent may be integrated within
suitable
H.323 components such as, e.g., the MCU or ihr gateway.
BRIEF DFSCRLPTION OF THE 1')RA,Wf.I~~IGS
A more complete understanding of Llhe present invention inay be had by
reference to the following Detailed l3escription when taken in conjunction
with the
accompanying drawings wherein:
FIG. 1 depicts a functional block diagram, of a wireless IP (WLIF) netwot~ in
accordance with the teachings of the present invention;
FiG. 2 depicts a functional block diagram of a pardon of the exemplary WLIP
network with additional components for providing 3P-based switehiug;
FIG_ 3 depicts a functional block diag~~m of an addressing scheme for use in
the ViTLIP network;
FIGS. 4A acrd 4B depict, respectively, control message pathways fox
ragistration and de-regisiration of a mobile station in the V~LIp network;
FIG. S depicts a control message pathway for placing a call from a mobile
station in the network:
FIG. 6 depicts a control message pathway for placing a call to a mobile
station
in the WLIP network;
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FIG. 7 depicts a control message pathway for an exemplary embodiment of a
call waiting scenario in the WLIP network;
FIG. 8 depicts a control message pathway for an exemplary embodiment of a
call enquiry scenario in the WLIP network;
FIG. 9 depicts a control message pathway for supporting an exemplary
embodiment of a mufti-party conference in the WLIP network;
FIG. 10 depicts a functional block diagram of another view of the WLTP
network portion for supporting mufti-party services using a Multipoint Control
Unit
(MCU);
FIG. 11 depicts a functional block diagram. of the WLD' network portion with
the MCU for supporting mufti-party services using ,a flash agent provided in
accordance with the teachings of the present invention;
FIGS. 12-14 depict control message pathways for additional embodiments of
a mufti-party conference using the flash agent; and
FIGS. 15 and 16 depict control message pathways for additional exemplary
embodiments of call waiting scenarios in the WLIP network portion having the
flash
agent.
DETAILED DESCRIPTION OF EMBODIMIM:NTS
FIG. 1 depicts a functional block diagram ~of a WLIP network system 100 for
providing H.323-based mobile switching in accordance with the teachings of the
present invention. A legacy PSTNlPLMN network portion 102 is connected to a
Home Location Register (HLR) 1 b0 via a Signaling System hIo. 7 (SS?) path
257. An
H.323-based VoIP portion 206 comprises an IF' network 207 disposed among a
plurality of H.323-compliant components such as, for example, a gatekeeper
200, one
or more terminals (e.g., terminal 203), one or more PCS (e.g., PC 202), a
Multipoint
Conference Unit (MC'I>7 204, et cetera.
1n order to integrate the VoIP network portion 206 with the POCS
infrastructure, a conventional Mobile Switching C'.enter (MSC) of the POCS
network
is modified in accordance with the teachin~s~f the present invention to
provide only
radio services. Accordingly, the switching functionality of the MSC is removed
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therefrom such than it becomes a Radio Networ;h Controller (RNC), for example,
RNC
130 shown in FIG. 1. A.n IP or RhTC gateway ?S0 is provided preferably as an
interface between the Ip network 207 and the ItNC 130. The IPIRNC gateway 250
is
an H.3?3-compliant gateway that is suitably tttodifled to support the
comrnttnication
S between the H.323 network acid the RNC I3!). An SS7lANSI-41 path 2I0 is used
between the RNC 130 and the IP gateway 250 during call setup. An ISI?N User
Part
(ISUP) signaling path 208 is also provided between the RNC 130 and the IP
gateway
?~0 in order to . establish trunk coiulectiorts fer'r voice transferring
dtuing the call.
The gatekeeper (GK) 200 operates as a mobility server for keeping 'track of
vatians call clients and servers. In addition, the gatekeeper 200 maintains
registration
and status information with respect to mobile stations (for example, MS 103)
and
H.323 clients in general- PrGferahly, the gatekeeper 200 is provided as an
H.323 entity
on the IP network 207 (which lnay comprise' a Local Area Network) that
provides
address tratulation alnd controls access to the network for the otherl"i.323
components.
IS The H.3?3 terminals (e.g., terminal 203) are preferably provided as 1P
clienu that may
transfer voice, video, and multimedia data- The MCTJ 204 is preferably
provided for
establishing conference calls and rnuIti-party services. Although not
specifically
shown in this FIG., a Multipoirst Controller (MC) may also be provided as part
of the
VoIP portion 206_ Furthermore, a "plain" PSTN gateway 249 may be provided
between the VoII' network portion 20b and the legacy PSTNIPLMN network portion
102 with a conneeuan 253. Alternatively, the legacy PSTNIPLMN network po~ttion
102 is coupled to the IP network 207 via the IPI~NC gateway 250. Accordingly,
it
should be realized that the GK 204 may decide to route a cah to the external
aetwork
(i.e., the PSTNIPLMN portion 102) via eithc~~ the IPIRNC GW 250 or the PSTN GW
ZS 249, using their respective paths alternatively ~(i-e., path 255 or path
253, respectively).
The G~ may also perform a load balancing or bandwidth control fvnctit~n with
respect
to such rousing to the external network poriit>tz.
FIG. 2 .illttsttates a functional diagtram of a relevant portion 202 of the
exemplary WLIP network system 100 shown in FIG. I, with additional details
provided for the gateway RNC interface pathway. A f~rsi protocol ua~rislaior
(TI) 304
is preferably provided as an SS7 stack or; the path 210 fat convetvng
Trausaction
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Capability Application Part (TCAP) messaging into suitable IP messaging. A
second
protocol translator (T2) 306 is provided on the path 208 for performing the
translation
between ISUP messaging and Primary Rate Ir.~terface (PRI} messaging. Those of
ordinary skill in the art should readily understand that either or both of the
translators
provided in accordance herewith may be integrated within the IP/RNC gateway
250
in some implementations. Further, although not shown in FIG. 1 or FIG.2,
cellular
entities such as, for example, a Visitor Location Register {VLR), one or more
base
stations, an Authentication Center (AC), Service Control Points (SCPs), et
cetera, may
be included within the WLIP network system 100.
Referring now to FIG. 3, shown therein is a functional block diagram of an
exemplary addressing scheme for use in the VVLIP network 100. Preferably, the
address translation between the Location Area (LA) and the RNC is performed
only
when the IP gateway 250 supports more than one. RNC. An RNC, e.g., RNC 130,
may
control one or more base stations (BSs). For <;xample, BS 140A and BS140B are
shown in this FIG. Translation between Mabile Identification Number (IVIll~
and LA
is preferably performed only when the LA information is to be maintained
within an
access network instead of the gatekeeper 200. The LA information may be
transmitted
to the gatekeeper 200 as a terminalAlias parameter in a Registration Request
(RRQ)
message and may be returned as a destinationlnfo or srclnfo parameter in an
Admission Confirm {ACF) message. It should be appreciated that the LA
information
may also be sent as nonStandardData in the RRQ and ACF messages. In a
presently
preferred exemplary embodiment ofthe present :invention, a mobile station (MS)
may
be paged globally.
Referring now to FIG. 4A, a control message pathway is illustrated therein for
registering an MS (e.g., MS 103) disposed in the WLIP network 100. After
determining that the MS 103 is located within its serving area, the serving
RNC 130
sends an AhtSI-41 private message, e.g., H32'3 Invoke message 602 to the RNC
gateway 250. The MSS-MRS RegUpdate signal is encapsulated within the H323
Invoke message 602. Upon receiving the InvolcE~ message 602, the RNC gateway
250
sends a RAS RRQ message 604 to the gatel~:eper 200.
If the MS has previously registered with a gateway within the domain of the
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gatekeeper 200, the gatekeeper 200 simply returns a RAS ACF message.
Otherwise,
it stores the MIN as an arias of the gateway and remirns a RAS Registration
Confirm
(RCF~ message 606. If the MS has failed the registration process; a R~IS
Registration
Reject (RR.>) return message (also labeled as message 606) may be sent. Upon
receiving either the ,RAS RCF AT RRJ message 606, the IPIR,NC gateway 250
constructs alt ANSI-41 private tnessage, H313 Return Restclt (RR) response
message
616, by wrapping the MSS-MRS RegUpdateR signal and returns it to the Rh'C 134.
FIG_ 4B depicts a control message pathway for de-registering an MS (e.g_, MS
103) in the WLIP network I QO provided it1 accordance with the teachings of
the
present iz?vention. The RNC 130 sends an ANSI-~~ 1 H323 Invoke message 6I 0
(with
encapsulated MSS-MRS RegUpdctte signal) to the IPlRNC gateway X50 to inform
the
)i.323 IP network 206 that the MS I03 has powe~:d down. Upon receiving the
H3Z3
Invoke message 610, the gateway 250 sends a R.AS Unregistratton Request (URQ)
I S message 61z to the gatekeeper 200 to remove. the MS fxom its registry. An
ert~poirztAlias parameter is provided within thE: RAS URQ message 6I3. After
determining that the registration of the MS can be revoked, the gatekeeper 200
updates
its tegisttyappropriately and $etids aRAS Unreg~strarion Conf rm (L1C.F~
message 614
to the IP1RNC gateway 350. if the registration of 'the MS cannot be revoked
for some
reason, the gatekeeper 200 transmits aIsAS Unregisrration Reject (ZIR.n
message (also
denoted as message 614) to the gateway. Thereafter, responsive to the UCF or
URl
message 614, the iPIRNC gateway 250 reads an ANSI-41 H323 RR response message
616 to the RNC 130, including the encapsulated RegUpdøreR signal thereiTi.
Referring to FIG. 5, depicted therein is a control message pathway for placing
a call from an MS to a terminal (e.g., terminal 203 shown in F1G_ 1 or FIG. 2)
disposed
in the WLIP network 100. An ANSI-41 H323 Invoke message 702 (with an
encapsulated SetizeTCII sigaal) is sent from the RNC 130 to the 1PlRNC gateway
zS 0.
Responsive thereto, a R~ISAdmission Request (Ai~~l) message 704 which includes
the
calling and caDed parties' nurrtbe~ (A# and B#, respectively) is sent fTOtn
the 1P/RNC
gateway 250 to the gatekeeper 200. A .RAS ACS' message 706 is then returned
from
the gatekeeper 200.
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After receiving the ACF message 70b, the IP/RNC gateway 250 determines if
the call can be handled. If not, an ANSI-4I H323 RR message 708 including
suitable
parametric information, e.g., CallCong parameter, is returned to the RNC 130.
Otherwise, the IP/RNC gateway 2S0 returns an ANSI-41 H323 Invoke message 7I0
S with a ConnectMS2 parameter to the RNC 130. In response thereto, an ANSI-41
H323
RR message 712 including a MSConnected parameter is returned to the gateway
250.
Subsequently, a trunk connection 714 is established between the gateway 250
and
RNC 130 using the B# and a suffix received in the MSConnected parameter.
Thereafter, a Q.931 Setup message ? 16 with appropriate parametric
information is sent from the IPlRNC gateway 250 to the terminal 203. In
response,
a Q.931 Call Proceeding message 718 is returned from the terminal 203 to the
gateway 250. The terminal 203 also engages in RAS :messaging with the
gatekeeper
200 as shown by the RAS ARQ and ACF messages 72:0 and 722, respectively. After
completing the RASmessaging, the terminal 203 sends a Q.931 Alertingmessage
724
1 S to the IP/RNC gateway 250. After a ringback tone 7.>.6 from the gateway
250 to the
RNC 130, a Q.93I Connect message 728 is sent by tlhe terminal 203 to the
gateway
250. Thereafter, an H.24S phase 730 is established !between the RNC 130 and
the
terminal 203.
Referring now to FIG. 6, illustrated therein is a control flow pathway for
placing a call to an MS from a terminal or a wireline phone. A voice gateway
(GW)
152 is provided as a media gateway, preferably for interfacing between the
VoIP
network portion and the PSTN (not shown). Pursuant to the call to be placed to
the
MS, the voice GW 1S2 first engages in RAS messaging with the gatekeeper 200 as
exemplified by ARQ and ACF messages 802 and $t)4, respectively. Thereafter, a
Q.93I Setup message 806 with appropriate parametric information is sent from
the
voice GW to the IP/RNC gateway 250. Responsive thereto, the IP/RNC gateway 250
sends a Call Proceeding message 808 to the voice G~JV 1 S2.
The IP/RNC gateway 2S0 then engages in its own RAS messaging with the
gatekeeper 200 as depicted by ARQ and ACF messages 8I0 and 812, respectively.
Subsequently, the IP/RNC gateway 2S0 sends an,l~NS~I-4I H323Invoke message 814
to the RNC 130 with a FindMSposl signal encapsulated therein. After
successfully
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finding the MS' location, the RNC 130 responds by returning an ATISI-41 H313
RR
message 816 with the encapsulated MSpasfouhdl signal- Thereafter, a trunk
connection 822 is established between the RNC 130 and the IPIRNC gateway 250,
pursuant to the H3.23 Invoke and RR messages 818 and 820; respectively. 'These
messages include, respectively, ConnecrMS1 and MSCo~t~tected parameters.
Subsequent to additional ANSI-41 H323 Invoke and ,R.R messages (messages 8z4
and
826, which include Alert Wirtfo andAlenWInfoR pa~'ameters, respect;vely)
between the
RNC 130 and the IP/RNC gateway 250, a Q.931 ~llerriag message 828 is
propagated
from the IP/RNC gateway 2S0 to the voice GW 152.
Thereat $ddition.al ANSI-aT 3i31.31nvoke aid RR messages (messages 830
and g32, respectively) between the RNC I 30 and the IflRNC gateway 250 give
rise
~o a Q_93I Connecr message 834 that is propagated from the IPlRNC gateway 250
to
the voce GW 152_ An H-245 phase 730 is then es~rabtished between the ltNC 130
and
voice GW I52.
1 S FIGS. 7 through 9 depict conaoi message pathways for multi-
partytransactions
involving prs~prietaty hash messages which are converted or mapped to
appropriate
H_323 messages by a flash proxy agent that is des~~ribed-in greater detail
hereinbelow:
Referring now to FIG- 7, a control message pathway for a call waiting scenario
involving a Private Branch Exchange (PBX) 100:2 in the WLIP network 100 is
shown
therein. A twa-parry call (desigltat~i as the .A-B cali) 1004 is fast
estabushdl
preferably in amatuter set fort3~ above. When a tturd party caller (C)
atcetnpts to teach
the B party, a number of Q.931 and RAS lacssag~es (messages 1006 - Z 020)
similar to
those described hereinahove are RroPagated mong the PBX 100?, voice GW 152,
IPIRNC gateway 250 and, the gatekeeper 200. Thereafter, a CaIIWa=ring tone
1022
2S is issued from the IPIRNC gateway 250 to the RNC 130 serving ihc MS. After
a
Q.931 Alening message 102 is sent from the gateway 250 to the k'BX 1002, a
flushwi~fo message 1024 is sent by the RN(. 130 to the IPlRNC gateway 250.
.Responsive thereto, a hold message 1028 is issued by the IP/RNC gateway 250
to the
voice GW 152 for holding The A-B call. A hold ark message is returned from the
voice GW 152 thereafter. Subsequently, a Q.93'1 Conned message 1032 is sent by
the
1P/,RNC gateway 250 to the PBX 1002 for effectuating the C-B call.
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FIG. 8 depicts a control message pathway for an exemplary call enquiry
scenario in the WL1P network 100 of the present invention. It should be
readily
appreciated that the establishment of a two-party call 1102 and subsequent
control
messages 1104 -1128 are similar to those described in greater detail in the
foregoing
sections. Accordingly, it is believed that the exemplary call enquiry method
is readily
apparent from FIG. 8 and the description above taken '.in conjunction
herewith.
Referring now to FIG. 9, depicted therein is a control message pathway for
supporting a three-party conference in the WLIP network 100. Preferably, a 3-
party
state 1202 is established with decentralized control, for example, in a
multicast
manner, of the parties involved. Aflashwinfo message '1204 is sent from the
RNC I30
to the If /RNC gateway 250 after a two-party call (e.g., .~-B call) has been
put on hold.
Responsive to the flashwinfo message 1204, the IP/RNC gateway 250 sends a
retrieve
message 1206 to the voice GW I52 in order to effectuate the retrieval of the
held A-B
call. A retrieve ack response message 1208 is returned from the voice GW 152
to the
I S IP/RNC gateway 250. It should be realized by those ~of ordinary skill in
the art that
the decentralized multipoint conference method of tlhe present invention may
not
involve apoint-to-point call setup ofthe participating terminalslclients with
the MCU.
Based on the foregoing, it should be appreciated that the present invention
advantageously provides an integrated wireless IP network solution for
realizing end-
user switching services on a packet-based network. Furthermore, the present
invention
provides an inexpensive way to integrate IP-based switching with cellular
networks
because of the ease of the provision of an IP switc;hing stack in a gateway
and
removing the costly MSC components from the network. Accordingly, it should be
further appreciated that by using the present invention, .operators can
quickly and cost-
effectively provide IP-based cellular telephony solutions within compact LAN
architectures.
In the following portions of the Detailed Description, a system and method is
provided for supporting mufti-party services in an intel~ated network using
the MCU
wherein conventional ANSI-53 messaging is appropriately mapped to suitable
H.323
procedures.
CA 02353582 2001-06-O1
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FIG. 10 depicts a functional block diagam of another view of the WLIP
network portion 1202 far supporting mufti-patty conferences using an MCU 1302.
Because the teachings of the present invention are exemplified using an 1:-
L323-based
network, a brief description of the H.3?3 entities is. provided hereinbelaw_
The H.323 standard def ties four major types of components for forn~g an
inter-operable network: terminals, gateways, gaceke.epers and multipoint
control units
(MCLJs). In general, terminals, gateways and MCUs of an H.323-based network
are
referred to as "endpoints-" Gateways are typicah.y provided between networks
{or
network portions) that operate based on different standards or protocols. For
eXample,
one err mare gateways may be provided between a packet-switched network
portion
and a circuit~switched network portion. Terminals are employed by end-users
for
accessing the network or portions thereoly for example, for placing or
receiving a call,
or for accessing multimedia content at a remote site.
The gatekeeper is typically defined as the entity on the network that provides
I S address translation and cozltrols access to tl;e netvaork for other H.323
components-
Usually, a gatekeeper is provided with the address wanslation capability for a
speci fled
portion of the network called a "zone: ' Accordingly, a plurality of
gatekeepers may
be provided for carrying out address translation that is necessary for the
entire
network, each gatekeeper being responsible for a particular zone. In addition,
gatekeepers may also pFOVide other services to ih~e terminals, gateways, and
MCUs
such as bandwidth management and gateway location.
The H.323 standard defines multiple types of add~tesses associated with each
endpoint such as, for exaruple, a transport address (which, for example,
corresponds
to the IP address and the port address of a tertnin~a operated by the end-
user) and an
alias address. A.n endpoint may have one or more aliases associated with it.
Exemplary aliases rttay include the well known E_'k64 telephone numbers, H.323
>Ds
(such as names, email-like addresse$, etc.), and so on_ 'j'he address
translation service
of the gatekeeper provides art alternative method of addressing an endpoint
wttercin
a user-friendly alias (e.g., the E.l6a telephone number) associated therewith
may be
translated into its appropriate transport address used by the ptotocol-
Continuing to refer to FIG. 10, the exemplary VoIP core network 206
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comprises one or more gatekeepers (e.g., gatekeepers 200A and 2008), one or
more
terminals (e.g., VCONI terminal 1304 and VCON:? terminal I306), et cetera, in
addition to the MCU 1302. Further, the gateway .?SO is preferably provided for
interfacing with a radio network controller (e.g., RNC I 30) as described
hereinabove.
S One or more base stations, for example, BS 1204, amd associated MSs (e.g.,
MS1
103A and MS2 1038) are preferably disposed in the cellular network portion of
the
WLIP network I00 as described hereinabove.
Conventionally, the MCU 1302 is provided within the H.323-based VoIP core
206 as an endpoint for providing the capability for three or more terminals
and
I O gateways to participate in a multipoint conference. V~Jhile the MCU 1302
is capable
of supporting a conference involving the H.323 enfiities, it is well-known
that the
current procedures used in setting up an H.323 conference do not support mufti-
party
services such as call enquiry, call waiting, or 3-party conferences, as
defined by the
mobile communications standard ANSI-S3.
15 FIG. I I depicts a functional block diagram of yet another view of the WLIP
network portion 1203 for supporting mufti-party services using a flash agent
203
provided in accordance with the teachings of the prcaent invention. Only
relevant
portions of the overall network architecture are depicted in this FIGURE. The
flash
agent 203 is preferably provided as a proxy device disposed between the
gateway 2S0
20 and the MCU 1302. Accordingly, the flash agent 203 maps an ANSI-S3 flash,
or such
other proprietary flash messages as maybe appropriate (e.g., the flash
messages shown
in FIGS. 7 through 9) to a suitable H.323 procedure for creating a conference
or
effectuating a mufti-party service. FIGS. 12-14 depict control message
pathways for
additional exemplary embodiments of a three-party conference service in
accordance
2S with the teachings of the present invention. FIGS. 1 S and 16 depict
control message
pathways for two additional exemplary call waiting scenarios, respectively. It
should
be understood that in each of these FIGURES described immediately hereinbelow
the
flash agent 203 is advantageously utilized between tire gateway 2S0 and MCU
1302
for mapping ANSI-S3 messages.
30 The scenario where an H.323 terminal (egg., VCONI 1304) is the creator of a
mufti-party conference is exemplified in FIG.12. Initially, the VCONI terminal
1304
CA 02353582 2001-06-O1
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creates a two-patty coufetettce with an MS by sending a Create message 1402 to
the
IVfCU 1302. The Create message I402 preferably includes a conference password
(e.g., 8711), a separator (which may be provided as a sequence of special
characters,
e.g., ~''), and the MS' telephone number' (e.g_, 888-555-0001 ). Ln response,
the MCU
S 1302 sends an I»vire message 1 t+04 which contains the password and
telephone
number information received from the VCON I temainal 1304 to the gateway 250_
.A.
Call 1406 is theft placed by the gateway 250 to the MS using this information
which
is routed via the RNC 130.
An ANSI-53 Flash message 1408 containing the third parry"s telephone
number, for example, the telephone number 7~7-S55-OpQ2 which belongs to the
YCON2 terminal 1306, is sent from the RNC 130 to the gateway 250, responsive
to
the data entered at the MS pursuant co a second eotaf ~rence password. When
the Flash
message 1408 is received at the gateway 250, the fit<~t conference passwot~d
(i.e., 8711 )
is preferably stored, and the LAN connection is put on hold (i.e., the )ZTP
speech
handler and a call handier associated with the initial two-patty conference
are
disassociated). A Create message 1412 is generated by the. gateway 250 Which
includes the second conference password {e.g., 8712), a separator (which may
again
be provided as a sequence of special chaTactets, e.g., ss), and the telephone
number
for the VCONZ terminal 1306. This message 1412 is sent from. the gateway 250
to the
MCU 1302.
Responsive to the Geate message 1412" the MCU 1302 sends an Invite
message 14I4 to the VCON2 terminal 1306, including the password Gild telephone
number information, fox connecting the tern~.inal with the MS. Thereafter; the
MS
toggles between the Qrigittal MS-VCONl conueciion azld the MS-VCON2
coruleCtiop
until a three-parry state is achieved. The wglling between the connections is
preferably effectuated by sending Flash messages with embedded codes (e.g.,
messages 1418,1422, and 1426) and propagating, Release messages {e.g.,
messages
1~i16apd14I8)betweenihegateway25flandtheV'CONtc~tsrtinals. Afteerestabtishing
the three-patty state pursuam to the Flash message I434, a Release message
1436 is
propagated between the gateway 250 arid the MhU 1342. Subsequently, the tluee
parties,.i.e., the MS and the two VCON terminals are engaged in. a phone
confes~tce.
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FIG. 13 depicts the control message pathway for the situation where the MS
is the creator of the original two-party conference with a VCON terminal. The
control
messages I 502 - 1536 are substantially similar to those described above in
reference
S to FIG. I2 and accordingly, only the salient features with respect to this
exemplary call
scenario are described herein. The MS creates and invites the VCONI terminal
1304
to the first conference connection via dialing a conference password (e:g.,
8711), a
separator, and the terminal's telephanenumber(e.g., 7'77-555-0001) (control
messages
1502, 1506, and 1508). Subsequently, after sending a Flash message 1504, the
MS
creates and invites the VCON2 terminal 1306 to the second conference
connection via
dialing another conference password (e.g., 8712), a separator, and the second
terminal's telephone number (e.g., 777-555-0002) (control messages 1512-1514).
FIG. 14 depicts the conference scenario wherE; two MSs, e.g., MS1 103A and
MS2 103B, are involved in the call connections. Again, only the salient
features of
I S this callflow are set forth. MS 1 103A is provided to be the creator of
the original two-
party call. MS2 103B is the creator of the enquiry two-party conference
connection.
MS1 creates and invites MS2 to the first conference via dialing in the data as
exemplified above. The control messages 1604-160E~ illustrate this callflow
portion.
MS2 creates and invites a terminal (e.g., the VCON'2 terminal 1306) to the
second
conference by dialing in the requisite data as shown lby messages 1614-1616.
After
a three-party state is achieved as explained in the foregoing, a Release
message 1638
is propagated between the gateway 250 and MCU 1302.
FIG. I S depicts a control message pathway for an exemplary embodiment of
a call waiting scenario in the WLIP network portion 12:03 provided in
accordance with
the teachings of the present invention. In this embodiment, MS 1 103A receives
a call
from the VGONI terminal 1304 while engaged in a two-party conference with MS2
103B, as shown by control messages 1702-1708. The call from the VCONl terminal
1304 is preferably effectuated in the same manner as described hereinabove.
After
receiving an Invite message 1712 from the MCU 130:2, an H.323 Admission
Request
(ARQ) message is sent from the gateway 25Q tc~the gatekeeper (not shown in
this
FIG.). Upon receiving an Admission Confirm (ACF) response message therefrom,
the
CA 02353582 2001-06-O1
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gateway 250 stores the ID of the call handler associated with the two-patty
conference
and issues a Call rYaiting tone 1716 to the RNC 13~D. Depending upon the dial
input
at the MS 1, three exernpIary events may then take place. For example, by
inputting
a "0" (message 1718}, a Release 1720 of the Call Waiting leg is effectuated
between
the gateway 2S0 and the VCONl terminal 1304. By inputting a "1" (message
1722),
the original two-p~Y connection is ieiminated (Release message 1726) and the
MSl
142A may then answer the waiting call (Connect message1728). 13y inputting a
"2",
the original call is put on hold and the MS answers the waiting call (Connect
message
1734).
FIG.16 depicts yet another exemplary emt~odiment of a call waiting ~cenaiio
in the WLIP ne~ork portion 1203 wherein MS 11 CI3A receives a call from
MS21038
while in a two-party conference with a terminal, e.;g., the VCON1 terminal
1304. The
establishment of the Ariginal twp-patty conference is exemplified by messages
1802-
1806. When MS2 1038 places a call, the RNC 13~D sends a Call From message 1808
to the gateway 250. Responsive thereto, a Call Waiting tone 1812 is issued fmm
the
gateway 250 to MS1_ Thereafter, an ARQ-ACF' messaging session is established
between the gateway 250 and the gatekeeper (not shown in this FIG.) so that
the
gateway 250 stores the ID of the call handler associated with the original two-
parry
conference. Subseguently, similarto the call waiting events described above,
multiple
call e~ettts maybe effectuated in this exemplary ennbodimerstby inpu~ing
appropriate
information at MS 1 103A_
It should be appreciated by those skilled in the art that the #lash agent 203
provided in accordance with the teachings hereiin advantageously converts
legacy
ANSI-53 messaging used for establishing mufti-party services into appropriate
Fi.323
2S messaging usable in a host of VoIP implementatic>ns. It should further be
appreciated
that the flash agent functionality, which may be suitably i:'itegrated within
a gateway
or other H.323 components of the network, may also be provided in conjtW
ctiouwith
the RNC t 30 disposed in the WLIP network portion 202 that includes suitable
protocol translators as disclosed herein with respect to FIG. 2.
Although the systems and methods of the various aspects of the prese~at
invention have been described in patlicular reference to the H.323 protocol
and ANSI-
i,
CA 02353582 2001-06-O1
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4I standards, it should be realized upon reference hereto that the innovative
teachings
contained herein are not necessarily limited thereto and may be implemented
advantageously with any applicable packet-switching protocols and radio
telecommunications standards.
S Furthermore, it is believed that the operation .and construction of the
various
aspects of the present invention will be apparent from the foregoing
description.
While the method and system shown and described h<~ve been characterized as
being
preferred, it will be readily apparent that various changes and modifications
could be
made therein without departing from the scope of the present invention as set
forth in
IO the following claims.
