System and method of group calling in mobile communications.
Abstract
Information is retrieved from a list of members of a group call group (Fig.7). Based on the retrieved information, a group call is established between first and second mobile stations (MS). The first MS is served by a first base station controller (BSC) and the second MS is served by a second BSC. Voice data for the group call is transmitted in a multicase session. Based on a history of group calls between two points in a mobile communications network, a determination is made as to whether to establish a multicast session between the two points, e.g., in anticipation of a future group call.

Term
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6 claims: 5 independent, 1 dependent
- 1NOVEDAD DE LA INVENCIÓN Habiendo descrito la presente invención se considera como novedad y por lo tanto se reclama como propiedad lo descrito en las siguientes reivindicaciones. REIVINDICACIONES 1. Un método para el uso en establecer una llamada en grupo, caracterizado porque comprende:recuperar información de una lista de miembros 10 de un grupo de llamada en grupo;y basándose en la información recuperada, establecer una llamada en grupo entre la primera y segunda estaciones móviles (MS), en donde la primera MS es servida por un primer controlador de estación base 15 (BSC) y la segunda MS es servida por un segundo BSC.
- 2El método de conformidad con la reivindicación 1, caracterizado porque la primera MS es servida por un primer centro de conmutación móvil (MSC) y la segunda MS es servida por un segundo MSC. 20 3. El método de conformidad conla reivindicación 1, caracterizado porque la primera MS y la segunda MS son servidas por un primer centrode conmutación móvil (MSC). 4. El método de conformidad conla 25 reivindicación 1, caracterizado porque además comprende:provocar que los datos de voz para la llamada en grupo se transmitan en una sesión de multiemisión. 5·. El método de conformidad con la reivindicación 1, caracterizado porque además comprende: dirigir los datos de voz para la llamada en grupo entre el primer y segundo conmutadores de procuración, en donde la primera MS es servida por el primer conmutador de procuración. 6. El método de conformidad con la reivindicación 5, caracterizado porque el primer conmutador de procuración recibe los datos directamente del primer BSC. 7. El método de conformidad con la reivindicación 5, caracterizado porque el primer conmutador de procuración recibe los datos del primer BSC mediante un primer centro de conmutación móvil (MSC). 8. El método de conformidad con la reivindicación 1, caracterizado porque por lo menos una porción de la llamada en grupo es medio doble. 9. El método de conformidad con la reivindicación 1, caracterizado porque además comprende: provocar que el control de habla se transfiera entre los miembros en la llamada en grupo. 10. El método de conformidad con la reivindicación 1, caracterizado porque además comprende: transmitir datos textuales por lo menos a una de las MS. 11. El método de conformidad con la reivindicación 1, caracterizado porque además comprende: 5 determinar cuáles miembros en la lista no están participando en la llamada en grupo. 12. El método de conformidad con la reivindicación 1, caracterizado porque además comprende: enviar una indicación de que un miembro carece 10 del control del habla en la llamada en grupo que ha pedido el control del habla en la llamada en grupo. 13. El método de conformidad con la reivindicación 1, caracterizado porque además comprende: antes de establecer la llamada en grupo, 15 establecer una sesión de multiemisión basándose en una predicción que tiene que ver con el establecimiento de la llamada en grupo. 14. Un método para su uso en establecer una llamada en grupo, caracterizado porque comprende: 20 recuperar información de una lista de miembros de un grupo de llamada en grupo;y basándose en la información recuperada, establecer una llamada en grupo entre la primera y segunda estaciones móviles (MS), en donde la primera MS 25 es servida por un primer estándar de señalización de ΊΟ radio y la segunda MS es servida por un segundo estándar de señalización en radio. 15. El método de conformidad con la reivindicación 14, caracterizado porque el primer 5 estándar de señalización de radio incluye una tecnología de acceso múltiple de división por tiempo, y el segundo estándar de señalización de radio incluye una tecnología de acceso múltiple de división por código. 16. Un método para su uso en establecer una 10 llamada en grupo, caracterizado porque comprende: basándose en un historial de llamadas en grupo entre dos puntos en una red de comunicaciones móvil, determinar si establecer una sesión de multiemisión entre los dos puntos. 15 17. El método de conformidad con la reivindicación 16, caracterizado porque además comprende: basándose en un historial de llamadas en grupo entre dos puntos en una red de comunicaciones móvil, predecir una demanda a futuro de las llamadas en grupo 20 entre los dos puntos. 18. El método de conformidad con la reivindicación 16, caracterizado porque además comprende: basándose en un historial de las llamadas en grupo entre dos puntos en una red de comunicaciones 25 móvil, determinar una topología de las sesiones de muitiemisión para utilizarse en una llamada en grupo a futuro en la red de comunicaciones móvil. 19. Un método para su uso en llamada en grupo, caracterizado porque comprende: 5 recuperar, mediante un primer controlador de estación base (BSC) , una indicación de que una primera estación móvil (MS) ha producido una señal de llamada que corresponde a una llamada en grupo;determinar que una segunda MS pertenece al 10 mismo grupo de llamada en grupo que la primera MS;poner en contacto la segunda MS, y establecer una sesión de multiemisión que transporta los datos de voz entre la primera MS y la segunda MS. 15 20. Un sistema para su uso en llamada en grupo, caracterizado porque comprende: primera lógica de llamada en grupo que recupera, mediante un primer controlador de estación base (BSC) , una indicación de que una primera estación móvil 20 (MS) ha producido una señal de llamada que corresponde a una llamada en grupo;segunda lógica de llamada en grupo que determina que una segunda MS pertenece al mismo grupo de llamada en grupo que la primera MS;25 tercer lógica de llamada en grupo que pone en ' RESUMEN DE LA INVENCIÓN - La información se recupera de una lista de miembros de un grupo de llamada en grupo. Basándose en la información recuperada, una llamada en grupo se establece 5 entre la primera y segunda estaciones móviles (MS) . La primera MS es servida por un primer controlador de estación base (ESC) y la segunda MS es servida por un segundo ESC. Los datos de voz para la llamada en grupo se transmiten en una sesión de multiemisión. Basándose en un 10 historial de llamadas en grupo entre dos puntos en una red de comunicaciones móvil, se hace una determinación en cuanto a si establecer una sesión de multiemisión entre los dos puntos, por ejemplo, en anticipación de una llamada en grupo a futuro. 2/19 FIGURA 2 r i i I I I I ! I I i l l I 1 I I MU í । INICIACIÓN DE LLAMADA EN GRUPO \ l \ I 1012Á MU LÓGICA DE LLAMADA EN GRUPO 1^1010 1012B 10120. M|J GRUPO 11014
- 33/19 RED DE IP DE MULTIEMISIÓN FIGURA 3
- 44/19 300 308 FIGURA 5 307 314 en 6/19 1070 1068A 1060D USUARIO n DE CUG BS O n 1062D 1064D J II , _ f _ BSCl MSC ;SW1 DE LLAMADA EN GRUPO 1066A MSC PLM/PSTN 1076 . SW2 DE LLAMADA EN GRUPO f 1066B 10680^. MSC ¡Wn DE LLAMADA EN GRUPol? ---- 7 -----------------K 1066C MSC 1072 1068B DIRECTORIO ACTIVO DE CUG RED DE IP HABILITADA POR MULTIEMISIÓN 7/19 1074 FIGURA 7 MS-A BSC-1 WCS-1 MG1 MG2 WCS-2 BSG-2 MS-B HLR GCR 1. MENSAJE DE , íl íí III FIGURA 8A 8/19 I I I 9/19 MS-A BSC-1 WCS-1 MG1 MG2 WCS-2 BSC-2 22. CONEXIÓN 11B27. CONEXIÓN ¡i 11B28. CONEXION ll ----------- —4¡11B28. CONEXION II 23.JONO EXITOSO____ REPRODUCIDO EN BANDA' ii I) _22, REPRODUCIR ll TONO (EXITO EN ’l MS-A) i[24, REPRODUCIR [aceptación DE “TONO MS-B HLR' GCR 11B23 iALERTACON. . Información 11B24. ORDEN DE__ w ACEPTACION DE Ms“* ^11B25. ORDENL_. DE CONEXIÓN 1JB26._ORDEN DE_ ACEPTACION DE BS 25. SESIÓN DE GIR EN PROGRESO (MS-A TIENE CONTROL DE HABLA) FIGURA 8C 10/19 I i I I 11/19 FIGURA 9 ι I I I I I I I I I 12/19 WCS-1 WCS-2 FIGURA 10 MS-1 BSC-1 WCS-1 MG1 MG2 WCS-2 BSC-2MS-2 HLR’ GCR 2. INICIAR DTME ----------Π----il il i! El ?
- 55^3. MODIFICAR •I CONEXIÓN ¡I. j(4. MODIFICAR ACEPTACION. ¡i DE CONEXION 5. CONTROL DE HABLA PARA LA SESIÓN DE GIR AHORA DISPONIBLE PARA TODOS LOS PARTICIPANTES EN LA LLAMADA :¡1. INICIAR DTMF 2. INICIAR DTMF ir n :i !f II ¡1 !I ¡i il il !l II !l !l il il 11 3. MODIFICAR t CONEXIÓN ¡4. MODIFICAR ACEPTACIÓN J DE CONEXION 5, REPRODUCIR ¡ TONO (ÉXITO EN I MS-B) 16. TONO DE ÉXITO i reproducidcTeñ BANDA |7. REPRODUCIR , ¡ACEPTACION DE TONO 1
- 68. SESIÓN DE G1R EN PROGRESO (MS-2 TIENE EL CONTROL DE HABLA) 13/19 FIGURA 11 DE 14/19 FIGURA 12 MSA G1 AD1 ABANDONAR HABLAR ADQUIRIR HABLAR -----------------------------------------------------1----------------TONO DE FALLA 16/19 FIG U RAM MS A CS1 HLR' 1 AD HLR'2 MSB CS2 MSC ACTUALIZACIÓN DE UBICACION ACTUALIZACIÓN .BE UBICÁCIóTr* ^.actualización) \de ubicación l . ACTUALIZACION DE UBICACIÓN ACTUALIZACIÓN DE UBICACIÓN ACTUALIZACIÓN DE UBICACIÓN ACTUALIZACIÓN DE UBICACIÓN ACTUALIZACIÓN ACTUALIZACIÓN DE UBICACIÓN DE UBICACIÓN 17/19 ENCONTRAR HLR' BASÁNDOSE EN IMSl/MIN/ESN ENCONTRAR TODOS LOS CUG EN LOS CUALES MIN/ESN PERTENECE Y ENCONTRAR EL AD DE CUG CORRESPONDIENTE FIGURA 15 D 18/19 FIGURA 16 19/19
Independent claims6
249 paragraphs in 29 sections, as filed
(54) Title: A SYSTEM AND A METHOD FOR GROUP CALLS IN MOBILE COMMUNICATIONS.
(54) Title: SYSTEM AND METHOD OF GROUP CALLING IN MOBILE COMMUNICATIONS.
(57) Summary
The information is retrieved from a list of members of a group call group. Based on the retrieved information, a group call is established between the first and second mobile stations (MS). The first MS is served by a first base station controller (BSC) and the second MS is served by a second BSC. The voice data for the group call is transmitted in a multicast session. Based on a history of group calls between two points in a mobile communication network, a determination is made as to whether to establish a multicast session between the two points, for example, in anticipation of a future group call.
(57) Abstract
Information is retrieved from a list of members of a group cali group (Fig. 7). Based on the retrieved information, a group cali is established between first and second mobile stations (MS). The first MS is served by a first base station controller (BSC) and the second MS is served by a second BSC. Voice data for the group cali is transmitted in a multicase session. Based on a history of group calis between two points in a mobile Communications network, a determination is made as to whether to establish a multicast session between the two points, eg, in anticipation of a future group cali.
<img file="MXPA03009869A_D0001.tif" />
(12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (19) World Inteilectual Property Organized International Burean (43) International Publication Date
November 2002 (07.11.2002)
<img file="MXPA03009869A_D0002.tif" />
PCT
IIIIIIIOIHIinilM (10) International Publication Number
WO 02/089501 Al (51) International Patent Classification<sup>7</sup>: H04Q 7/00,
7/20, 1/30, H04B 1/06, 7/26 (21) International Application Number: PCT / US02 / 12884 (22) International Fiiing Date: 24 April 2002 (24.04.2002) (25) Fiiing Language: English (26) Publication Language: English (30) Priority Data:
09 / 845,934 30 April 2001 (30.04.2001) US (71) Applicant: WINPHORIA NETWORKS, INC. [US / US]; 3 Highland Drive, Tewksbury, MA 01876 (US).
(72) Inventor: VISHWANATHAN, Kumar, K .; 6 Squire Armor Road, Windham, NH 03087 (US). SUNDAR, Rangamani; 5 Squire Armor Road, Windham, NH 03087 (US). ARAVAMUDAN, Murali; 3 Squire Armor
Road, Windham, NH 03087 (US). NAQVI, Shamim, A .; 19 Spring Valley Road, Morristown, NI 07960 (US). RAMAKRISHNAN, Kajamalai, G .; Apt. 204, 11 Old Boston Road, Tewksbury, MA 01876 (US). IYER, Prakash, R .; 6205 Archstone Avenue, Tewksbury, MA 01876 (US).
(74) Agents: DICHIARA, Peter, M. et al .; Hale and Dorr LLP, 60 State Street, Boston, ΜΛ 02109 (US).
(81) Designated States (national): AE, AG, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, BZ, CA, CH, CN, CO, CR, CU, CZ, DÉ , DK, DM, DZ, EC, EE, ES, H, GB, GD, GE, GH, GM<sup>Z</sup>HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, > MX, MZ, NO, NZ, OM, PH, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TN, TR, TT, TZ, UA, UG, UZ , VN, YU, ZA, ZM, ZW.
(84) Designated States (regional): ARIPO patent (GH, GM, KE, LS, MW, MZ, SD, SL, SZ, TZ, UG, ZM, ZW), Eurasian patent (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), Europcan patent (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE, TR), OAPI patent
[Continued on next page] wo 02/089501 Al ιιιιιιιι
1060A 4 ^ 1
<img file="MXPA03009869A_D0003.tif" />
1062A, 1064A
Bts
BS
CUG USER 1
1060B
CUG USER 2
BS2
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1066A
BS
1062B, 1064B
1060C
CUG USER m
BSp
1062C. 1064C
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BS
1060D
BSq
1062D, 10640
<img file="MXPA03009869A_D0006.tif" />
BS
CUG USER n
1070
1068A
GROUP CALL SW1
GROUP CALL SW2
1066B
1068C ^ MSC
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PLM / PSTN
1074
CUG ACTIVE DlñECTORYp (GROUP CALL SWnf ^ 1066C
MULTICAST
ENABLED
IP NETWORK
1068B
1072
1076 (57) Abstract: Information is retrieved from a list of members of a group cali group (Fig. 7). Based on the retrieved Information, a group cali is established between first and second mobile stations (MS). The first MS is served by a firet base station controller (BSC) and the second MS is served by a second BSC. Voice data for the group cali is transmitted in a multicase session. Based on a history of group calis between two points in a mobile Communications network, a determination is made as to whether to establish a mullicast session between the two points, cg, in anticipation of a future group cali.
WO 02/089501 Al Η · ΙΙ · Ι · Ι ^^^ (Bb, BJ, CF, CG, Cl, CM, GA, GN, GQ, GW, ML, MR, Fortwo-letter codes and therabbreviations, reference the GuidNE, SN, TO, TG). <sub>ance Noles on Codes</sub> and Abbreviations appearingat the beginPublished: <sup>n</sup>'<sup>n8 each issue</sup> ° f<sup>the Pcr</sup> Gazette.
- with International search report
SYSTEM AND METHOD FOR GROUP CALLING IN MOBILE COMMUNICATIONS
1. Field of Invention
This invention relates to mobile communications, and more particularly to a system and method for group calling in mobile communications.
two. Background of the Invention
All mobile modem communication systems have a hierarchical arrangement, in which a geographic coverage area is divided into a number of smaller geographic areas called cells. Referring to Figure 1, each cell preferably is served by a Base Transceiver Station (BTS) 102a. Several BTS 102b-n are added via the fixed link 104a-n on a Base Station Controller 106a (BSC). The BTS and BSCs are sometimes collectively referred to as the Base Station (BS) Subsystem 107. Several of the BSCs 106b-n can be added to a Mobile Switching Center (MSC) 110 via the fixed link 108a-n.
The MSC 110 acts as a local switched exchange (with traditional features to handle mobility management requirements, discussed in the following) and communicates with the telephone network 120 (PSTN) via truncated groups. Under the mobile networks of the United States, there is a concept of a local MSC and a serving MSC. The local MSC is the MSC corresponding to the exchange associated with a Mobile Station (MS); this association is based on the telephone number, eg area code, of the MS. (The local MSC is responsible for the HLR discussed in the following). The serving MSC, on the other hand, is the exchange used to connect the MS call to the PSTN (when the subscriber roams in the area covered by the service provider, different MSCs perform the function of the serving MSC). Consequently, sometimes the local MSC and the serving MSC are the same entity, but other times they are not (for example, when the MS is roaming. Typically, a Visitation Location Record 116 (VLR) is co- located with the MSC 110 and a logically unique HLR is used in the mobile network As 20 will be explained in the following, the HLR and VLR are used to store many types of subscriber information and profiles.
Briefly, one or more radio channels 112 are associated with the entire coverage area. The 25 radio channels are divided into groups of channels assigned to individual cells. Channels are used to carry the signaling information to establish call connections and the like, and to carry voice or data information once a call connection is established.
At a relatively high level of abstraction, mobile network signaling involves at least two main aspects. One aspect involves signaling between an MS and the rest of the network. With 2G (2G being the industry term used for second generation) and the latest technology, this signaling has to do with access methods used with the MS (for example, time division multiple access or TDMA; code division multiple access , or CDMA), radio channel assignment, authentication, etc. A second aspect involves the signaling between the various entities in the mobile network, such as the signaling between the MSCs, VLRs, Hlr, etc. This second part is sometimes referred to as the Mobile Application Part (MAP) especially when used in the context of System No. 7 is Signaling (SS7).
The various forms of signaling (as well as voice and data communication) are transmitted and received in accordance with various standards. For example, the Electronic Industries Association (EIA) and the
Telecommunications Industry Association (TIA) help define many North American standards, such as IS-41, which is a MAP standard. Similarly, the CCITT and ITU help define international standards, such as GSM-MAP, which is an international MAP standard. Information on these standards is well known and can be found from relevant organizational bodies as well as in the literature, see, for example, Bosse, SIGNALING IN 10 TELECOMMUNICATIONS NETWORKS (Wiley 1998).
To provide a call from an MS 114, a user dials the number and presses send on a cell phone or other MS. MS 114 sends the dialed number indicating the required service to MSC 110 via BS 107. MSC 110 checks with an associated VLR 116 (below) to determine whether MS 114 is allowed the required service. The serving MSC routes the call to the user's local exchange dialed on PSTN 12 0. The local exchange alerts the called user terminal, and a counter response signal is routed back to the MS 114 through the serving MSC 110 which then completes the conversation path to the MS. Once the establishment is complete, the call can proceed.
To provide a call to an MS .114 (assuming the call originates from the PSTN 120), the PSTN user dials the associated telephone number of the MS. At least according to North American standards, the PSTN 12 0 routes the call to the local MSC 5 of the MS (which may or may not be the one serving the MS). The MSC then interrogates the HLR 118 to determine which MSC is currently serving the MS. This also acts to inform the serving MSC that a call is forthcoming. The local MSC then routes the call to the serving MSC. The serving MSC searches for the MS using the appropriate BS. The MS responds and the appropriate signaling links are established.
During a call, BS 107 and MS 114 may cooperate to change channels or BTS 102, if needed, for example due to signal conditions. These changes are known as handoffs and involve their own well-known message types and signaling.
One aspect of ΜΆΡ involves mobility management. Briefly, different BSs and MSCs may be needed and used to serve one MS, since the MS 114 roams in different locations. Mobility management ensures that the serving MSC gets the subscriber profile and other information needed by the serving MSC to calls (and bill) correctly. For this purpose, the MSCs use a Visitation Location Register 116 (VLR) and a Local Location Register 118 (HLR). The HLR is used to store and retrieve the Mobile Identification Number (MIN), Electronic Serial Number (ESN), MS status, and MS service profile, among other things. The VLR stores similar information in addition to storing an MSC ID that identifies the MSC (Local).
Furthermore, under appropriate MAP protocols, the location update procedures (or registration notifications) are performed so that the local MSC of a mobile subscriber knows the location of those users. These procedures are used when an MS roams from one location to another or when an MS is powered on and registers itself to access the network. For example, a location update procedure may proceed with the MS 114 sending a location update request to the
VLR 116 via BS 107 and MSC 110. VLR 116 sends a location update message to HLR 118 serving MS 114, and the subscriber profile is downloaded from HLR 118 to VLR 116. MS 114 an acceptance of a successful location update is sent to you. The HLR 118 asks the VLR (if any) that previously held the profile data to override the data related to the relocated MS 114.
Figure 2 shows in greater detail the signaling and user traffic interfaces between a BS 107 and an MSC 110 in a CDMA mobile network. The BS 107 communicates the signaling information using the Al interface. The A2 interface carries user traffic (eg, voice signals) between the MSC switching component 204 and the BS 107. The interface A5 is used to provide a path for user traffic for circuit switched data call (as opposed to voice calls) between the resource BS and the MSC.
Also, subscribers who are demanding 15 newer services (eg data calls) to the Internet. For some of these services, MSCs are not cost effective because they are primarily designed for voice calls. The integration of new services within the MSC is complicated or not feasible 20 due to the proprietary and closed designs used by many MSC software architectures. That is, the software logic required to provide the services is not easy to add to the MSC 110. Often times, a switching adjunct is used to provide such services. For example, a Function of
Internal Work (IWF) is an attachment to mourning a data call to the Internet. Any procedure, integrating functionality within the MSC or adding a truncated side attachment - involves the MSC at service entry 5. As the new service is expected to stimulate demand, integrating new services through MSC design changes or through truncated-side attachments will likely exacerbate network congestion at MSC and require expensive MCS resources.
With respect to the Internet, multi-destination communication refers to the transmission of identical data packets to multiple selected destinations on an Internet Protocol Network. (In contrast, broadcast communication refers to an indiscriminate transmission of data packets to all destinations, and single-destination communication refers to the transmission of data packets to a single destination.)
Each participant in a multicast receives information transmitted by any other participant in the multicast. Users connected to the network who are not participants in a particular broadcast do not receive the information transmitted by the participants in the broadcast. In this way, multi-destination communication uses only the network components (eg, switches and trunks) currently required for multicast transmission.
In multicast processing, when a potential participant (host) is directed to join a particular IP multicast group, the host sends a request message to join the router with. closest multi-cast capability to require joining the multi-cast group and receive the information sent to this group. For example, host A sends a message to join multicast group Y, and host D sends a message to join multicast group X. A router R propagates the request to the multicast source if the data path is no longer in place.
Upon receipt of an IP packet for group X, for example, router R maps an IP multicast group address to an Ethernet multicast address, and forwards the resulting Ethernet packet to the appropriate switch (s).
According to the current Internet Group Management Protocol (IGMP), a host's membership in a broadcast group expires when the router does not receive a periodic membership report from the host.
Regarding the interaction between MS, a Nextel service (known as Nextel Direct Connect®, using Specialized Mobile Radio technology, and 5 described at http: //www.nextel.eom/pho: ne_service / directconnect. Shtml ) which has two versions that have been proposed for special connection calls between MSs. Both versions of the special connection calls require that all members be located in the same area served by a BSC. In the first version, a one-to-one conversation is allowed between two mobile phone subscribers, for example A and B.
When A wishes to have special connection communication with B, A enters B's private identification number, 15 holds down a push-to-talk (PTT) button, waits for an audible prompt that means B is ready to receive, and begins to speak. To listen, A releases the PTT button. If B wishes to speak, B holds down the PTT button and waits for an audible confirmation that A is ready to receive. The service allows a subscriber to choose private identification numbers from lists displayed on mobile phone units or to search a list of pre-stored names of subscribers.
In the second version, conversations are allowed between members of a predefined group of subscribers, known as a Conference Group, which is identified by a number. The mobile phone unit allows Conference Group numbers to be searched through the unit's control surface. In order to make a group call, the initiating subscriber, for example A, locates a Conference Group number on the unit, holds down the PTT button, and with reception on audible confirmation such as chirp, can start talking. All other Talk Group members in the group call can listen only while A is holding down the PTT button. If A releases the PTT button, another member in the group call can hold down the PTT button, acquire control signaled by the audible confirmation, and begin speaking.
Summary of the Invention
The invention generally provides mobile communication systems and methods and specifically provides a system and method for group calling. The information is retrieved from a list of members of a group call group. Based on the retrieved information, a group call is established between the first and second mobile stations (MS). The first MS is served by a first base station controller (BSC) and the second MS is served by a second BSC. The voice data for the group call is transmitted in a broadcast session. Based on a history of group calls between two points in a mobile communication network, a determination is made as to whether to establish a multicast session between the two points (eg, in anticipation of a future group call.
By initiating a single call, a member of a group can cause a group call to be established between all members of the group who may be online. Group calls can be established between members who can be located in different areas served by different BSCs and perhaps by different access methods (eg TDMA or CDMA). Internal BSC voice traffic between members in a group call may be carried over an alternative communication network such as a network of
Internet Protocol.
Brief Description of Drawings
In the drawings:
FIG. 1 is a prior art mobile network system diagram; í
Figure 2 illustrates a prior art interface between a BS and a mobile switching center in a prior art mobile network;
Figure 3 illustrates a block diagram of a system that includes group call logic;
Figures 4-5 illustrate a proxy switch and certain deployments in a mobile network;
Figure 6 illustrates an exemplary data plane of a proxy switch in accordance with a preferred embodiment of the invention;
Figures 7, 9, 16-17 illustrate architectures of a group communication system;
Figures 8a-8c, 11-15 are call flow diagrams of uses of a group communication system; Y
Figure 10 illustrates a flow chart of group call logic.
Detailed description of the invention
With reference to Figure 3, a system and method is provided for arranging calls between members of a predefined group of mobile phone users. As described in greater detail in the following, a proxy switch or other device that implements call 1010 logic in
I group detects a group call initiation by a member 1012a of a group 1014 and automatically tries to connect all members 1012a, 1012b, 1012c of the group in a group call. In a specific implementation, group call communication is two-way (that is, only one member can speak at a time, and voice traffic for the group is carried over an Internet Protocol (IP) network in a multi-broadcast session.
With respect to the case in which group call logic is implemented by a proxy switch, the proxy switch may operate as described in co-pending US application Serial No. 09/721329, entitled System and
Method of Servicing Mobile Communications with a Proxy Switch, filed Nov. 22, 2000, which is incorporated herein by reference. As described in the co-pending application and illustrated in Figure 4, switching operations 1034 are performed between at least one mobile switching center (MSC) 1030 and at least one base station (BS) subsystem 1032. The switching allows communication traffic to be siphoned to or from an alternate network 1036 such as an IP network. The communication is transparent so that neither the MSC nor the BS need any changes to work with the inventive switching.
The proxy switch described in the co-pending application includes signaling message handling logic 1038 to receive the signaling messages from the MSC and BS in accordance with a mobile signaling protocol. The message interception logic 1040 cooperates with the signaling message handling logic and sends an acceptance message to an MSC or 10 BS that transmitted a signaling message. The message interception logic also prevents the signaling messages from being sent to another of the BS and MSC respectively. The message conversion logic 1042 cooperates with the signaling message handling logic and converts a signaling message from one of the MSC and BS into a converted signaling message for transmission to the other from the BS and MSC, respectively. The message transmission logic 1044 cooperates with the signaling message handling logic and transmits the signaling messages from one of the MSC and the BS to the other of the BS and MSC respectively.
A set of BS support circuitry 1046 is assigned to the proxy switch. The signaling messages 25 between the MSC and the BS are received and analyzed to determine and correspond to the assigned set of support circuits. If so, the control information in the signaling messages is transported to the alternate communication network; and the information carried on the carrier circuitry is siphoned into the alternate network.
Figure 5 shows a preferred development of a proxy switch 300, in which the proxy switch 300 is positioned between BS 107 and MSC 110. Only a subset of main lines 306 carrying user traffic needs to be terminated at the proxy switch; other main lines 308 can directly connect MSC 110 and BS 107. All control links 312 of BS 107 terminate at proxy switch 3 00. The proxy switch includes a control plane 302 and a data plane 3 04 (also known as a support plane). Control plane 3 02 handles all signaling traffic, and data plane 304 handles all user traffic for the trunk lines connected to the proxy switch.
Under certain embodiments, there is a one-to-one correspondence between an MSC and a proxy switch. Multiple BSs can work with a single proxy switch.
The proxy switch 300 includes software that accepts all signaling messages and, depending on the message and the state of the system, does at least one of the following:
1. passes the message unaltered to the MSC or BS addressed in the message;
two. intercepts the messages between the MSC and the BS;
3. for some intercepted messages, it converts the intercepted messages into a different message and sends the converted message instead of the original, the intercepted message to the MSC or BS addressed in the intercepted message;
Four. Siphons the message from the mobile and PSTN-based network to an alternative network such as an IP network.
The types of actions performed in each case together with the trigger events are described in the following.
In many cases, particularly when a message from an MS 114 is siphoned and traffic is directed to an alternate network, the proxy switch 300 can act as an MSC 110. In such a role, the proxy switch fulfills the responsibilities and roles that a traditional MSC can perform. Some of these functions and roles pertain to mobility management. Consider the case of a roaming MSC; since it roams from one cell to another, it can roam a cell served by a different MSC 5, thus necessitating a handoff between the source and the target MSCs. If the proxy switch 300 has siphoned the message and the call / session has been directed to an alternate network, then the handover is handled by the proxy switch analogously to the way a handover can be handled by a conventional MSC. The proxy switch causes the appropriate databases to be updated with the new location of the MS.
Another function of the proxy switch pertains to resource allocation. In particular, when an MS initiates a message that requires a new call / session, appropriate circuits (channels) need to be allocated for this session. Depending on the system configuration and the state of the system, the proxy switch makes the assignments analogously to the way the conventional MSC assigns to the circuits.
Figure 6 shows an exemplary development in which the proxy switch 300 is connected to several alternative networks, such as a structure 412 ι
IP main or an alternate circuit based network 414, eg, a different carrier. These alternative networks can be used to carry voice and / or data traffic to desired destinations while completely or partially avoiding the PSTN 120 along with the costly resources of the MSC 110. Alternatively, these arrangements can be used so that circuit traffic can be carried back to a different network; eg Nashua loop traffic, 10 NH can be trailed back to an MSC in Waltham MA. 0 can be used to connect to other networks. For example, the IP backbone 412 can communicate with the IP voice networks 418 or the Internet 416. As explained in the co-pending application, when the traffic to an alternative network is siphoned, both the control information (for example, from the signaling messages) and the voice or data from the support circuits on the links 306 they can be sent over an alternative network.
In a specific implementation of the group communication system introduced in the above, mobile communication users (user) belonging to a closed user group (group or CUG) are provided with an ability to make contact with each other quickly and easily and consequently start talking to each other. Each group includes two or more users (members), and a user can belong to multiple CUGs. Conversations can occur between two members of a group (private mode) or between all available members of a CUG (public mode). The group communication system uses conventional mobile communication equipment such as cell phones and mobile PDAs.
In a specific implementation, the group communication system implements group call logic on logically arranged proxy switches between MSC and ESC as described above to intercept group call initiations, bypass MSCs and PSTNs, and implement group calls as IP multicast sessions that perform Voice over IP (VoIP). Users in a group can be served in disparate geographical locations by multiple MSCs making intervals of an aggregate network that relies on one or more wireless technologies such as CDMA. TDMA (including IS-136 and GSM), GPRS, and third generation technologies. For example, among group members joined in any group call, one or more users can roam on a GSM network simultaneously with one or more users roaming on a CDMA network. Control information pertaining to a group call can be made available - to one or more users' such as deployment participants in the group call while the group call is in progress. Group call lists 5 can be dynamically created and modified by the group call user, using standard membership schemes such as MIN, IMSI and ESN.
The general architecture for an exemplary embodiment of the group communication system is shown by example in Figure 7. Figure 7 shows four. users in a group call using wireless 1060a-1060d devices connected on different 1062A-1062D BTS systems. For purposes of the following description, it is assumed that wireless devices 15 have both textual and audio display capabilities. The BTSs connect to 1064A-1064D Base Station Controllers (BSCs), which connect to proxy switches that implement the 1066A-1066C group call logic 20 (group call switches). Each group call switch connects to an MSC such as MSC 1068<sup>to</sup>, 1068B, or 1068C. At least one group call switch is provided for each MSC in a group call service enabled network. With respect to the signaling information, each group call switch is logically located between a corresponding-BSC and a corresponding MSC. The group call switch receives the signaling and data from the MSC and in the reverse direction from the wireless devices via the BTS and the BSC. Each group call switch operates in such a way that neither the BSC nor the MSC is aware that the group call switch lies between the BSC and the MSC. Signaling and control information from the MSC and BSC is intercepted by the group call switch and passed without defined limits to the involved elements as required without any discernible change.
The MSCs connect to the 1070 Public Land Mobile Network (PLMN) and the group call switches 15 connect to an IP network 1072 enabled by backbone multicast (backbone network), which provides access to a Directory 1074 CUG Asset and a 1076 Local Location Record I
Improved (HLR).
As described above with respect to the co-pending request proxy switch, the group call switch includes a control plane and a data plane. The functions in the control plane are the termination of signaling messages from the BSC or the MSC or both. For example, \
Instead of CDMA, signaling messages are defined by the IS-634 protocol specification. The control plane terminates the incoming signals and generates new signaling messages for transmission near the MSC or other elements. The control plane also supports a multicast function described in the following.
In a particular embodiment, the group call switch data plane receives 10 TDM traffic from the BSC or the MSC or both and uses a TDM cross-connection (DACS) (Figure 5) to interconnect the incoming traffic to a outgoing destination. In other embodiments, the data plane can also receive incoming IP traffic from Base Station 15 complex (also known as the radio access network, or RAN), and change incoming IP traffic to outgoing IP traffic. . The scheduling control in the control plane determines the cross connections between the incoming TDM traffic and the outgoing destinations, particularly the traditional MSC and / or the destinations in an IP network.
In the case of the MSC serving as the outgoing destination of the DASC, the group call switch is essentially transparent to the network; traffic 25 and control flow without defined limits from the BSC to the
MSC and from MSC to BSC. When the outgoing destination is in place on an IP network, a media gateway (described in the co-pending application) in the data plane diverts selected portions of the incoming TDM traffic from the MSC and converts the incoming TDM traffic into traffic. RTP / UD / IP and push the RTP / UD / IP traffic into the backbone IP network.
The CUG Active Directory (CUG AD) also known as Group Call Record 10 (GCR), is a database system that contains CUG data. In a specific implementation, a CUG AD in Figure 15 is implemented as a distributed database system for scalability. The CUG AD contains the definitions of all the CUGs in the group call network. A request to the CUG AD specifies the identifier of a CUG, that is, the request requests the definition of a specific CUG, and the result is a list of group user IDs for all members of the specific CUG. For example, a request that specifies CUG ID 2347 can cause the CUG AD to produce a result that identifies the Mobile Identification Numbers xxx, yyy, zzz, and www (the MINs) for the four users on the CUG. In a specific implementation, the MIN numbers are assigned to the GIR service users 25 by the service provider.
Each CUG is identified to the system by a unique identifier ID derived from a CUG name slot that is divided such that the different divisions are assigned to different distributed parts of the CUG AD. A division index of the division scheme is made available to all group call switches. When a group call switch needs to retrieve the definition of a CUG, the group call switch can use index 10 to determine the AD component of the CUG to be required.
The enhanced HLR 1076 is an enhanced version of the standard HLR database (standard HLR) used in cellular telephony. The standard HLR 15 produces field location updates from roaming mobile users. The traditional path through these updates is from a mobile phone to the BTS, from the BTS to the BSC and then over the MSC, which sends an update message to the HLR. In a specific implementation of the group call network, the group call switch is located between the BSC and the MSC, which makes all location updates visible to the group call switch. For users who have subscribed to the group call service, the group call switch intercepts the location update messages and duplicates them to the HLR '. In addition to consequently storing the cell location of the group call users, the HLR 'also stores a list of all the CUGs to which each group call user belongs. A request to the HLR 'specifies a MIN that identifies a group call user and produces a response that includes a list of CUGs in which the group call user is a member.
In a specific implementation, the HLR 'is a distributed database in which the data distribution is based on the MIN hierarchy. Alternatively, the HLR 'may also be based on the International Mobile Subscriber ID 15 (IMSI) or Equipment Serial Number (ESN). An index similar to the split index described above for the CUG namespace allows a group call switch to determine the split of HLR 'to be requested when an incoming request is to be processed.
In the following example for a family, a CUG can be defined as having Dad, Mom, and Teen users, each of whom carries a cell phone. By pressing a special sequence of passwords on his cell phone (or a special passcode if provided on the phone), Dad can cause a group call initiation process to run that locates Mom and Teen and invites Mom and the Teen to join a group call. In the dual media implementation described above, when the group communication system confirms that at least one member of the CUG has joined the group call, Dad who is the initiating joined member is assigned control of speak and can start speaking 10 while the other joined member or members listen.
When Dad gives up speech control, any of the other joined members of the CUG (for example the Teen if the Teen has joined the call) can gain control of speech and speak. Thus, in the dual medium implementation, only the joined member who has been assigned speaking control; another joined member cannot speak until speech control is re-left and reassigned. As described in detail in the following, to request a speech control, 20 a user in a group call can press a standard number key on the phone, can press a special key if provided by the phone manufacturer, or You can send a text message to the current speaker who requires speaking later, if all 25 phones have text message capability. If at any point during the call speech control. remains unassigned for a predetermined period of time (that is, the conversation is done), the call is terminated.
A group call can be accommodated when all members of a CUG are in the same switching area, that is, in a geographic area controlled by a single MSC or proxy switch, or they are in different switching areas. For example, in the case of a CUG that has users A, B, C, and D, A and B can currently roam in the SI switching area, C in the S2 switching area, and D in the S3 switching area. commutation. If the switching areas SI, S2, S3 and S4 are all operated by the same service provider or managed by operators who have agreed to cooperate with each other to offer group call service, a group call can be established so that it connects A, B, C, and D. If so, individuals can be widely dispersed with respect to physical location, for example, A and B can be in Boston, C can be in Texas, and D can be in California.
The group communication system provides call interoperability through heterogeneous network technologies, that is, it allows a group call to be established regardless of whether the members of a CUG are roaming through networks that are based on different technologies. For example, user A may be in Boston Roaming on a Code Division Multiple Access (CDMA) based network while B is roaming in the United Kingdom (UK) on a Global System for Mobile Communications ( GSM) (GSM uses Time Division Multiple Access (TDMA) technology). If A and B belong to the same CUG and the CDMA and GSM operators have agreed to cooperate in offering the group call service, a group call can *
settle between A and B.
The system may include one or more of the following enhancements, which are described in more detail in the following. As is apparent from the above description, a group call can be established regardless of whether all members of a CUG cannot join in a group call, an exception list listing the missing members can be generated and logged by the system. . If one or more CUG members have phones that have display screens, the exception list can be displayed on the display screens. Additional actions can be taken based on the exception list. For example, during or after the call, a voicemail message can be sent to the members listed on the exception list; For example, the voicemail message can be logged once by the call initiator and 5 can be delivered by the group communication system to voicemail mailboxes at pre-specified voicemail phone numbers for members in the exception list. Instead or in addition, CUG members joined to a particular group call 10 can be enlisted on the available display screens of the phones of all joined members during the call, to make each joined member aware of other members. they are on the call. A visual indication may be provided on the available display screens to identify the member currently in control of speech.
A private call can be established by one user of the group communication system with another user of the group communication system, so that the users can discuss confidential or personal information outside of a group call. Thus, two participants in a continuous group call can temporarily join into a private call and then return to the continuous I i group call. A user of the group communication system can request a list of the group calls in progress (active group calls) for the CUGs in which the user is a member, and join one of the calls. A user of the group communication system can initiate or join a public group call, that is, a group call for a CUG that includes each user of the group communication system. An operator can define any number of public user groups (PUGs). Each user of the group communication system automatically becomes a member of all PUGs. To join an active public group call, the user requests a list of active public group calls and selects a call in which they participate.
If a user of the group communication system has the ability to hold the call, the user can place a group call and hang up and answer an incoming call signal. A user who does not want to accept any of the incoming call signals, including for group calls, can activate call forwarding or call blocking. A user can 'choose to block only incoming call signals for group calls, for private calls, 25 or for both.
The group communication system can incorporate conversation-to-text translations into group calls for the benefit of users who are in a noisy environment, users in public places where the use of the audible telephone is restricted, and hear disabled users and can incorporate language translations (for example, from English to French).
A user of the group communication system 10 can be contacted using the user's mobile phone number or a special group communication system identification number (group user ID) that the service provider can assign during recruitment. group service 15 based on contact information that is stored in the user's telephone directory. Group user IDs can be self-establishing (self-provisioning) instead of or in addition to using a web-based provisioning system as described in the following.
As noted in the above, the group communication system provides three modes of operation: Closed User Group (CUG) mode, Private mode, and Public User Group (PUG) mode. 25 Except for user-controlled calls, i<sup>&</sup> As described in the following, the user presses one. number key (or special phone key if provided) to speak, and expect to hear a tone indicating that the user has been granted speech control. When the user is finishing speaking, the user can press a key, which causes the other joined users to hear a tone indicating that speech control is available. Another joined user can then press a key, hear a tone, and begin speaking. The initiator begins speech control after at least * one other user has joined the call as indicated as indicated by a ¡tone. The call ends when all joined users have hung up or when speech control has not been required for a period of time, as noted above. The system arbitrarily resolves conflicts between simultaneous user requests for speech control. For example, a
Human Protocol can be used if a full duplex mode for conversations is available. In such a case, control can be passed to multiple users, so that eventually all but one user becomes silent, and control of speech is transferred to that un-silent user.
In CUG mode, group call users form a Closed User Group by creating a unique group ID for a list and assign members to the list using the members' group call IDs and their mobile phone numbers. For 5 handsets to be designated by the Radio Access Network (RAN) under the direction of the proxy switch, since the RAN uses mobile phone numbers to effect signaling, the CUG information includes mobile phone numbers . 10 Each CUG includes two or more users, optionally with a maximum size imposed by the service provider.
In a specific implementation, if the group call user wants to make contact with a group of users in the user community (i.e. 15 CUG mode), the user keys in a call initiation sequence (enter) , for example, * 4 followed by the CUG ID, and press the send key. (The call initiation sequence can also be stored and dialed from the user's telephone speed dial 2 0 territory.) A CUG member who is unable to join the call when notified first can join the call later, if the call is still active, by entering the call start sequence and pressing the send key.
In CUG mode, the call initiator has the option of requesting a user-controlled call, which is a call that has an interrupt capability. Based on the ability to interrupt, a listening user can send an alert message to the speaking user by pressing a sequence of service configurable DTMF keys to indicate to the speaking user that the listening user would like to take over. speech. At that point, the speaking user can press a key 10 to leave speech control, or can continue speaking. Accordingly, the ability to interrupt provides the speaking user with an audible notification of a listening user's desire to speak, and, in the case of a telephone having a text display, it may also provide a text message displaying the name of the user listening to who sent the break message. In this way, the speaking user is not forced to guess that a listening user would like to speak. When the speaking user does not want 20 interruptions (for example, during the announcement to a large group of people), the ability to interrupt can be disabled.
As described in the above, the CUG mode can also provide an attention report with the speaker identification ability and an attention exception with the broadcast ability.
Call transcription capability can be provided in CUG mode so that talk-to-text technology is used to transcribe a group call in real time. A group member who has a text display phone and is notified of the group call can request to silence the call and instead receive a text transcript. In a specific embodiment, a phone without text display 10 sends and receives audio only and a text-only device such as a text browser receives the text, and if the call transcription capability is not turned on, the text-only devices they are not notified of the group call. A full transcript of the call may be available at the end of the call, and may be sent to all CUG members, CUG members who did not join the call (based on a care exception list), or the origin Of the call. The capacity can be extended to 20 translation services, using the preferred language indicator available with IS-41-c. The preferred language indicator is an item of information included in the subscriber's profile and stored in the HLR database, to indicate a subscriber's preference for the language in which advertisements and other reports should be presented. The switch uses the preferred language indicator when playing pre-stored announcements. Additional resources such as the human or automated translator can be provided by the service provider.
Group caller IDs and the associated list of members can be established using a web-based provisioning application from a personal computer, or from a WAP-enabled device. The user can also establish a list of the user's mobile phone. The service provider specifies the limit to the number of members in a list, the network or networks the members belong to, and the number of lists that a group call user can maintain.
In private mode, the group call user can quickly invoke a call to any member of the user group that connects to a group call enabled network by entering the group call initiation sequence, for example, * 4 followed by the group call ID of the intended recipient member, and press send. The intended recipient member is notified of a call from the user and, in a specific embodiment, the user hears a chirp when the intended recipient member has answered the call.
In PUG mode, the group call user can view a list of current talk groups and decide to join a talk group. The group call user can create a new group of 5 conversation that is available to any group call user, by specifying a unique group call ID and providing a short text description of the group topic. The subscriber can optionally associate a text name with the caller ID in group, as long as the text name is unique across the current active talk groups.
The group calling feature does not take precedence over existing mobile phone features such as call forwarding, no disturbance, and call blocking. Callers in a group call are able to switch to an incoming call if you are enabling call waiting. Three forms of calling, conference calling, and call transfer are disabled during a group call for security reasons, and are re-enabled at the completion of the group call.
The group call service supports conversation encryption using the IS-41-C (VP) Voice Privacy feature, as required by the mobile phone, if the corresponding base station supports VP.
<sub>4</sub> In a specific implementation described in greater detail in the following, the group call service operates on the IP network using multicasting.
IP. As described above, IP multicast allows a source to send a single copy of a stream of VoIP packets that is received by multiple receivers who have explicitly registered to receive the stream. Multicasting is a receiver-based concept whereby receivers join a particular multicast session group and the stream is delivered to all members of that group via the network infrastructure. Only one copy of a multicast stream is passed over any link in the IP network, and copies are made only on IP multicast-enabled media gateways as needed.
In the wireless network, the service has certain characteristics of any conventional wireless call. As described above, the group call initiator invokes a group call by sending a DTMF feature escape sequence followed by the ID of the group call list of users that the initiator wants to contact (for example , * 4 followed by the user group ID). The escape sequence feature is used by the proxy switch to detect that the call is a group call and requests the Global Call Log (GCR or CUG AD) to retrieve the list of mobile phones to contact and their current locations . The current location information determines which Media Gateways and BSCs will be involved in the group call. Support channels are established between each BSC and the corresponding Media Gateway via the data plane of the group call switch. The group call is presented to each BSC as having conventional point-to-point call setup and demolition characteristics and is not presented to the MSC.
An exemplary call flow diagram for basic service within the wireless network is shown in Figures 8A-8C, where WCS-1 and WCS-2 represent group call switches. Referring to Figures 9-10, also, the main entities in the flow chart are the group call switches WCS-1, WCS-2 having respective media gateways MG1, MG2; a GCR that is accessible by WCS-2; the BSC, BSC-1, BSC-2; and mobile stations (eg telephone) MS-A, MS-B. In the example MS-A and
MS-B are covered by the same WCS-1 group call switch, but the procedure may be the same if MS-A and MS-B are covered by different group call switches.
Figure 10 illustrates a group call logic flow diagram that summarizes the call flow diagram of Figures 10A-10C for setting up a group call. The share of logic handled by WCS-1 is shown on the left and the share of logic handled by WCS-2 is shown on the right. The WCS-1 detects that MS-A has requested a group call (step 3010) and thus informs the WCS-2 (the group call coordinator) (step 3020). The WCS-2 refers to the GCR to determine the other MS-A CUG members and their last known locations (step 3030). (In this simple example, MS-B represents just another member.) WCS-2 creates a Media Gateway connection to WCS-1 (the group call switch for MS-A) (step 3040). WCS-1 acquires a wireless channel for MS-A (stage
3050). WCS-2 tells WCS-1 (the group call switch for MS-B) to search for MS-B (step 3060). WCS-1 searches for MS-B (step 3070) and then informs WCS-2 that MS-B was found (step 3080). WCS-2 creates a Media Gateway connection to WCS-1 (the group call switch for MS-B) (step 3090). WCS-1 acquires a channel '.<sup>42</sup>
I '-' wireless for MS-B (step 4000) and WCS-2 informs that the. acquisition has been accomplished (step 4010). WCS-2 tells WCS1 to tell MS-A that MS-B is reached (step 4020) and then causes a tone to be played to MS-A through Media Gateways (step 4030).
I Examples of additional call flows are explained in the following along with Figures 12-15.
As described above, in group calls, • only one joined user is allowed to speak at a time; a joined user who has control of speaking can abandon control by sending a predetermined DTMF digit (eg 1), and another joined user can then request control of speech by sending a DTMF digit (eg 8). The joined user who is in control of speech hears a success tone played when the send path is established as shown in Figure 11.
Prior to the group call, a group call user can choose to enable or disable one or more of the following features described in the above: Attention Exception Report, Attention Report, Call Transcription, and Ability to Break In.
In the established web-based system that is available to end users to establish their GCR lists, the web server connects to the GCR over a. IP binding to enable real-time updates of user group call lists. The establishment system supports the WAP protocol as well as the industry standard browsers.
Call records are collected by all participants in a group call, for accounting and network design purposes.
Figure 12 illustrates an example, now described, of a group call service application. According to the example, CUG1 is a CUG that has four users A, B, C and D. Users A and B are i currently served by group call switch G1, C is served by call switch G2 in group, and D is served by the group call switch G3. Users have been assigned to unique MINs through the group call service provider. For simplicity, unique MINs are referred to as A, B, C, and D, here. CUG1 has a unique identifier that is assigned by the service provider represented here, such as CUG1. The definition of CUG1, that is, the membership list of CUG1, is kept in a distributed component i of the CUG AD called AD1.
In a first exemplary exercise, a group call originates from A to group CUG1, ie, B, C and 'D. Figure 12 is a call flow diagram of the „group call.
A originates a group call request for the closed user group CUG1. The IS634 interface, 5 the request is represented as a CM_service_request with CUG1. In the case of the Radio Access Network (RAM), the request is very similar to any other call request. The IS634 commands and the information elements involved include, among other 10 information points, the calling number and the called number (eg assumed by CUG1 in the current example). In at least some cases, the RAM does not have the logic to distinguish valid numbering plans from invalid numbering plans, the logic of which can be implemented in the MSC. In such cases, the RAM sends the number information as part of the IS634 J message set at the MSC. As for the proxy switch that intercepts such messages, the number information i becomes available to the proxy switch. Since the proxy switch can operate in at least certain ways like an MSC, the proxy switch can determine that an incoming call request is not a conventional call request, but rather a group call request for a group. closed user. In such a case, the proxy switch assumes the role of a. group call switch and initiates the procedures for a group call.
The group call switch G1 issues a channel assignment request back to A. G1 also initiates a directory transaction to retrieve the definition of a group CUG1 of AD1 from the AD component of CUG. The response from AD1 is expected to include the list of MINs corresponding to the group CUG1 members, that is, B, C and D. When the response is received, G1 has been obtained from the following information:
CUG1 includes members B, C and D (in addition to A) '15 MIN B is the responsibility of the G1 switch (i.e. itself)
MIN C is the responsibility of the G2 switch MIN D is the responsibility of the G3 switch G1 initiates a call setup request to B (which is the responsibility of G1 itself) and sends the call setup requests to G2 and G3 for C and D respectively. Thus, G2 and G3 act as proxy switches for G1 for this particular group call. G1 also ensures that a new context is created in which TDM traffic is
I directs from the RAN to the Media Gateway, which converts the TDMA traffic into RTP / UDP / IP packets and forwards the RTP / UDP / IP packets to a multicast router. The multicast router is instructed to receive the packets and add A to the multicast group, and multicast the packets to the specific multicast group. In the call flow diagram of Figure 18, the instructions are shown collectively as Union Multicast Group (TDMA).
Gl then waits to connect the messages from B, G2, and G3. Any of these three messages can be received in any order, and only a subset of them may be received. In the example, Gl, 15 first receives a connect message from B, followed by the connect message from G2 and G3. Upon receipt of the connection message from B, Gl sends a Union Multicast Group (TDM B) message which causes the Media Gateway to accept the RTP / UDP / IP traffic from the multicast router, converts the RTP traffic / UDP / IP on TDM and sends the TDM to the Gl switch which will cause the TDM to be transmitted via the BSC and the BTS to B. The multicast router is instructed to add B to the current multicast group. Thus, for current group calling purposes, the switch Gl serves as a source of TDM traffic and the switch G2 serves as a collector for TDM traffic. '
In the example, C sends a connect message to
G2 (that is, the switch that is responsible for C), which in turn sends a connect message to G1. G1 then sends a Union Multicast Group message (TDM C) causing C to join the group call in the RECEIVE mode. Similarly, the connect message from D to G3 is relayed to G1 causing D to be added to the multicast group.
The Media Gateway is instructed by the control plane to receive or send packets on certain RTP ports only in a particular context. All 15 packets are multicast by the router to multicast members.
Since, at this junction G1 has received at least one configuration from a user who has joined the group call, G1 sends a success tone to A 20 indicating that the group call can now proceed.
A is in the SEND mode and B and D are in the RECEIVE mode, and the broadcast router can broadcast to B, C, and D.
In another exemplary exercise, a speech control transfer is performed, as illustrated in the call flow diagram of Figure 13.
* Specifically, A abandons speech control which is acquired by C. '
To leave speech control, A points to
Gl which causes Gl to put the current group call into IDLE mode. (As explained above, if no user requires speech control within a specified time when measured by a system timer, the group call is terminated).
C issues a Talk, Acquisition command to the responsible G2 switch. Since, for current group calling purposes, switches G2 and G3 are proxies for Gl which is the control switch, the talk / acquire command is relieved to
Gl. Gl issues a CHANGE CONTEXT command to the Media Gateway that causes the Media Gateway associated with the switching G2 to accept incoming TDMA traffic from C, convert the TDMA traffic to RTP / UDP / IP and send the RTP / UDP / IP to multicast router. The Media Gateway is instructed to stop receiving TDM traffic from A. The multicast router is instructed to change the mode from A to RECEIVE and the mode from C to SEND. Gl issues a Concession Talk message to G2 that sends a success tone to C indicating that C can now proceed to
I 'speak. The broadcast session can now proceed as shown with C as the speaker and A, B, and D as the listeners.
If B, for example, issues a message from
Acquisition conversation while speech control is with C, the message is sent to the G1 switch responsible for P which denies the request (because C has not left speech control) and sends a trouble tone message to B .
In a further example, the situation is simplified so that the group call has two parties A and B, with A having control of speech. The network includes a single group call switch G1 that includes a control plane CS and controls two media Gateways MG1 and MG2. Traffic to and from A travels via MG1 and traffic to and from B travels via MG2, as illustrated in the call flow diagram of Figure 14.
Since A is in control of speech, the system responds to an Abandon Control command only from A. The command is received by the G1 control plane CS which issues a Modify Context command to MG1 that instructs MG1 to modify the call context by deprecating TDM traffic from A. The system goes into an INACTIVE state waiting for an Acquisition Control command. If no command is received within a specified time period as measured by an inactivity timer, a Call Release request is sent from CS to A and MS B. In addition, destruction context commands are sent to MG1 and MG2. The group call release sequence is complete when Release Complete messages are received from A and B and Destruction of Context complete messages are received from MG1 and MG2.
Figure 15 illustrates an example of the call flow with respect to the database record that is kept in the case of roaming. That is, location update.
Three mobile stations A, B and C are involved. A and B are the responsibility of a control plane CS1 of one group call switch and C is the responsibility of a control plane CS2 of another group call switch. A roams and issues a location update that is received by CS1 via the BTS and BSC. CS1 queries the index based on IMSl / MIN / ESN to determine the appropriate HLR 'for A, eg, HLR'l, and issues a location update request to HLR'l. HLR'l determines through its database all the CUGs to which A belongs. With this information, HLR'l issues a location update request to CUG AD. Consequently, CUG AD includes the updated location of A in the CUGs to which A. belongs.
While roaming, B also issues a location update, which comes to CS1. On the basis of IMSl / MIN / ESN, CS1 determines the appropriate HLR 'for B, particularly HLR'2. CS1 issues a location update request to HLR'2 that finds all the CUGs to which B. belongs. HLR'2 issues a location update request to CUG AD that asks CUG AD to update all CUGs to which belongs to B with the new location of B.
Location updates from C are received in CS2. CS2 determines the appropriate HLR ', e.g. HLR'2, sends the location update to HLR'2, which asks CUG AD to update the corresponding CUGs for C.
Variations
The above modalities facilitate all the making of the inventive group call. Subsets of the functionality, however, still provide advantages over the state of the art. For example, the group call that uses technology. different to multicast on the IP network still can. offer many of the advantages discussed above.
In particular, the standard telephone connections using PTSN can be inserted instead of the IP multicast connections.
In another example, the group call switch can be deployed on the trunk (back) side of the MSC. In such mode, the group call feature can operate as described in the following.
Figure 16 illustrates a group call switch deployed on the back side of the MSC, with the links fixed using standard ISDN User Part (ISUP) land line signaling.
The MSC connects to the Local Location Register (HLR) using the IS-41 protocol (also known as MAP). The group call switch and the MSC are also interconnected with the main support lines that carry the voice traffic between the two switches.
The group call switch has a TDM connection to the PSTN and an IP connection to an IP network from its data plane (also known as a Media Gateway). The group call switch can also ask the HLR to use IS-41. (Figure 16 shows the two MSC switches independently connected to ί.
'the PSTN, but both switches can connect to the. same PSTN). Both group call switches have access to Active Directory (CUG AD) over the IP network.
The development shown in Figure 16 can be used for group calling. For example, mobile Station A (MS) can connect to MSC-1 via RAN-1 and two mobile Stations B and C can connect to MSC-2 via RAN-2. Subscriber A may have a CUG 10 that includes B and C as members. As explained above, A can use a special group call initiation sequence to signal to the MSC that he wishes to make a group call. The logic of MSC-1 determines that the incoming call request is a group call and forwards the call request to the group call switch GCS-1 using the ISUP protocol. The group call switch GCS-1 uses its internal logic to access the Active Director's CUG AD to determine the members of the called CUG.
In this example, the request produces the MIN numbers of members B and C. In this case of deployment on the back side of the MSC, the group call switch does not have access to I location updates; since HLR<sup>F</sup> it does not contain the current locations of the called mobile stations. However, the HLR contains this information. In this way, the group call switch GCS-1 can make an IS-41 request (location request) to the HLR requesting the location of mobile stations B and C. For example purposes, mobile stations B and C may currently be located in a switching area controlled by MSC-2. Following standard mobile phone practice, this information is contained in the HLR database and the HLR now contacts MSC-2 10 (via a route request). Regarding MSC-2 that<sup>1</sup> You are using GCS-2 on the trunk side, the route request from the HLR is received by GCS-2. GCS-2 returns the Temporary Local Directory Number (TLDN) to the HLR that sends this information to the issuer (GCS-1) of the original location request. GCS-1 determines that TLDN belongs to GCS-2 and notifies GCS-2 about the group call. GCS-2 instructs MSC-2 to establish a group call at mobile stations B and C. Additional interactions proceeded as described above for the no backside case, with MSC-1 and MSC-2 effectively becoming transparent for group call purposes.
The later side of the switch development for group calling has a care benefit that may be apparent from Figure 16. In the case of such a development, land line phones. such as the telephone D shown in the
Figure 16, they can also get involved in a group call. In this way, a CUG member can register a landline telephone number as their reach number in the CUG Active Directory. If such a subscriber such as D needs to be included in a group call, the relevant group call switch may request the Serving MSC to complete a call from PSTN to D using the subscriber's stored reach number.
As described above, IP multicast technology can be used as the basic transport technology for group calling. However, in at least certain cases, the I
<td>implementations</td><td>standards</td><td>of</td><td>the</td><td>technology</td><td>of</td>
<td>multi-issue</td><td colspan="2">IP can test</td><td>to be</td><td>inefficient</td><td>for</td>
<td>satisfy the</td><td>needs</td><td>of</td><td>the</td><td>members of</td><td>CUG</td>
widely dispersed. Call setup 20 per dynamic call of multicast tunnels to carry traffic between multicast enabled routers can take an excessively long time. Subscribers who experience long group call setup times may place or retry the call, which can result in!
in unsatisfactory user experience. Long delays in call setup times can also lead to inefficient signaling network utilization.
For example, as shown in Figure 17, a number of multicast enabled routers, eg MCR-1, MCR-2, MCR-3, can be present in an IP network. In the example, the locations of these routers are fixed and not subject to change. The 10 multicast routers connect to group call switches (either in front of the MSC or on the back side of the MSC as described above) and thus to mobile phones via the Corresponding Radio Access Networks ( RAN).
(Although Figure 17 shows each multicast router connected, to a single group call switch, multiple group call switches can be connected to a single router.) If a subscriber initiates a group call based on the
0 members of the relevant CUG, one or more of the multicast routers can be involved in the call. In particular, the tunnels are established between the corresponding multicast routers as noted above. If the establishment of these 25 tunnels is delayed excessively, the quality of the group call may suffer as a result.
As now described, IP tunnels can be established in advance so that a number of group call initiation requests 5 arriving later can be served by these tunnels. For tunnels that are established in advance of future group call requests, the post-initiation set-up delay is accordingly reduced or eliminated. The tasks involved include predicting the demand for group calls that are expected to arrive in the future, and determining the topology of the tunnels that IP needs to be established to meet the anticipated demand.
The demand forecast relies on the .15 historical information in the form of the group call record. The group call history is divided into series, windows, with each window being defined for a length of time, known as the window size, which can vary from a couple of minutes to 20 several dozen minutes and is proportional to the average wait times for group calls. The current window size used in the demand prediction can vary based on the desired precision of the predictions and the computational resources that are used in deriving the predictions. Generally, shorter window sizes provide more accurate predictions. than larger window sizes as they cause more useless consumption of computing resources. Also, shorter windows tend to be more sensitive to burst traffic and make filtered aberrations less likely.
Each window includes a group call request number, along with the parameters that describe the calls, that is, the number of G and R calls between either of two multicast routers. As discussed in the following, X (I, J, N) denotes the number of group calls between routers I and J in window N.
The following example illustrates the forecast of future demand for group calls. In the example, the group call history is divided into 4 windows, with window 1 being the first in time and window 4 being the last in time (ie the current window). To calculate the demand in the next (future) window, that is, to window 5, the following filtration formula is used:
X (I, J, 5) = (1-a) * X (I, J, 4) + a * (1-a) * X (I, J, 3) + a * a * (Ια) * X (I, J, 2) + a * a * a * (la) * X (I, J, 1)
In the formula, a (alpha) is an empirically determined weighting factor with a value between 25 0 and 1. As expressed in the formula, the traffic prediction for the next time window is based on. give more preference to more recent windows than to previous windows. This preference is clearly apparent if the formula is rewritten in its more general recurring form, as follows:
X (I, J, N) - (la) * X (I, J, N-1) + α * Χ '(I, J, N-1)
Where X '(I, J, N-1) is the filtered estimate that encapsulates past history up to Nl.
In the formula, Current refers to the last window in the time sequence. Based on this formula and given a history of demands (windows A to N), as exemplified by the values of the parameter X (I, J, N), a table of values T (I, J) (demand matrix) can be calculated for the next window, so the value in row J and column J represents the number of group calls expected in the rising corner window between multicast routers I and J.
With regard to determining the tunnel topology to meet demand, the following information is used for inputs: the point-to-point demand matrix for group calls between either of the two multicast routers; a cost structure of the tunnels by the service provider, that is, the cost of establishing a tunnel of a particular capacity between either of the two 'routers'; the service provider's delay guarantees, that is, the maximum delay in the IP transport network between any of the two particular multicast routers 5; and the quality of service (QoS) constraints that need to be satisfied by group calls.
In view of such inputs, the topology of the tunnels between the multicast routers, that is, which tunnels and with what capacity connect to the multicast routers, is determined in a way that the topology explains the following constraints: tunnels emanating from each multicast router do not exceed the router's total output capacity (in bits per second), and the number of tunnels emanating from each multicast router does not exceed the internal limit on the number of tunnels in the router.
As described in the following, an Integer Linear Programming (ILP) mathematical optimization technique 20 is used to determine the <sup>1</sup> least cost topology, in view of the following points, as explained in the following. A recognition that the case is NP-difficult, and a formulation of the task as a multi-comfort flow of restricted degree that can be solved using ILP techniques.
According to the NP-difficult theory, a case that can be shown to be NP-difficult is not expected to have an efficient algorithmic solution. A given case, for example X, can be shown to be NP-difficult by considering a case already taken as NP-difficult, for example Y, and showing that Y reduces to X in a polynomial time transformation. The tunnel topology design 10 case can be shown to be NP-difficult by noting that it is a generalization of the multi-comfort flow problem that cannot be split (see J. Kleinberg, Single source unsplittable flow, Proc, of the 37th IEEE Symposium on Foundations of Computer 15 Science, 1996).
In this way, the tunnel topology case is reshaped in a way, shown in the following, that is suitable for the application of ILP approximation techniques.
ENTRY
Let N denote the number of multicast routers on the network.
Let D (max, l) denote the maximum number of tunnels that router I can establish.
Let P (t, J) denote the unit cost of tunnel 1 for the main line of type t. Here, 1 denotes a node pair l = (i, j) for multicast-enabled routers (the MCRs) i and j.
Let i (Tau) denote the set of all possible types of main lines (DSO, DS1, 0C3, etc.)
Let T (I, J) denote the demand matrix, that is, the expected group call traffic between routers I and J for a given future time period 10,
Let C (I) denote the capacity of router I in bits per second.
Let R (I, J) be the set of all viable routes to mourn the traffic between router 15 I and J.
(This is a pre-processing stage that generates all viable quality of service paths between MCRs I and J).
OUTPUT DECISION VARIABLES
Y (t, l): number of units of type t main lines assigned on link 1.
X (p): amount of traffic flow on path p.
Zi: a binary valued variable with the value if link 1 is assigned non-zero capacity; otherwise its value is zero.
ILP FORMULATION ·
Diminish . Σ Σ pW<sup>5 1</sup> Ter subject to • Demand Satisfaction (the tunnel topology satisfies the demand matrix):
Σ Xp * ν<sub>Μ </sub>peRy · Sufficient Tunnel Capacity (the total flow in all paths can be managed by the capacity of the main lines chosen):
Σ Σ Σ yi 'vi ij peR¡j tet y lep · Port Restrictions (the number of tunnels that emanate and terminate at a router do not exceed the router's maximum internal set):
£ Z | <Dr Vi
Σ 2a á Dj ^ Vj) :( ij) =<sup>TO</sup>l
The previous analysis is formalized in the following.
ENTRY
N: number of routers
Gave<sup>max</sup>: maximum number of tunnels that router i can establish
Ρ1<sup>ϋ</sup>: unit cost of tunnel 1 for the main line type t τ: set of all possible types of main lines: demand matrix T (I, J)
Cí: capacity of router i (bis / sec)
Rij: set of all viable routes to route traffic between router i and j
OUTPUT DECISION VARIABLES: number of t-type trunk units assigned to link 1 x<sub>P</sub>: amount of flow (volume of traffic) on paths p
Zi: = 1 if link 1 is assigned non-zero capacity = 0 otherwise
ILP formulation
Diminish
X pW tei submit · Satisfaction of demand
Σ * Ρ * Ty Vij peRij • Sufficient tunnel capacity
Σ Σ Σ y / vi ij peRy tet y
......
• Port restrictions £ 2 ^ <D ·, ™ V¡
Ι: (Μ) =<sup>Δ</sup>1 £ Zj <Dj ™ Vj
1: (ίΰ) = Ί · Tunnel Existence Restriction.
Σ and> 'vi
Zi 2 teT
------ where Μ = (ΣΣΤ «) + ε Μ ij where ε, a coefficient of decrease, is a given user parameter that has a value that is greater than zero.
Furthermore, to the extent that the modalities have been described in the context of particular wireless technologies such as the TDMA or CDMA protocols, the modalities can also be modified to work with wireless technologies that include one or more of the following: TDMA, CDMA, GSM, IS-136, and other 2G and 3G protocols.
Having described an exemplary modality, it should be apparent to those skilled in the art that changes can be made to the described modality without
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24 members in 10 offices
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| 0212884 | United States of America | W |
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| AU2003243429A1 | Australia | A1 | |
| KR20040002932A | Republic of Korea | A | |
| EP1391124A1 | European Patent Office (EPO) | A1 | |
| MXPA03009869AThis record | Mexico | A | |
| BR0209308A | Brazil | A | |
| KR20050007596A | Republic of Korea | A | |
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| EP1527624A1 | European Patent Office (EPO) | A1 | |
| CN1672438A | China | A | |
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| CN1830219A | China | A | |
| EP1391124A4 | European Patent Office (EPO) | A4 | |
| CN1314279C | China | C | |
| EP1527624A4 | European Patent Office (EPO) | A4 |
1 legal event, as the office reported them to INPADOC
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Numbers
- Application
- 3009869
Titles2
- English
- SYSTEM AND METHOD OF GROUP CALLING IN MOBILE COMMUNICATIONS.
- Spanish
- UN SISTEMA Y UN METODO PARA LLAMADAS EN GRUPO EN COMUNICACIONES MOVILES.
Classification
- CPC, 12
- H04L67/04
- H04W4/10
- H04W8/186
- H04W76/45
- H04W76/40
- H04W76/20
- H04L67/564
- H04L67/566
- H04L67/565
- H04L67/56
- H04W72/30
- H04L9/40
- IPC, 6
- H04M3 42
- H04L29 06
- H04L29 08
- H04W4 06
- H04W4 10
- H04W76 04