Voice over internet protocol (VoIP) multi-user conferencing

Abstract

Voice Over Internet Protocol (VoIP) devices are invited to a conference bridge based on a pre-defined criteria for the conference bridge (e.g., passengers on a plane. The conference invite messages are transmitted using Internet Protocol, which they may or may not accept. The invited VoIP users may be determined based on their physical proximity to the initial caller and other pre-determined characteristics. A VoIP soft switch includes conference bridges that eliminate the conventional requirement that they dial the phone number of another specific VoIP communications device. Instead, location information relating to the initial VoIP user is passed to the VoIP conference bridge, either from the user's VoIP communication device or from their respective location server. Location and other information is then compared by the VoIP soft switch against other VoIP devices, to find potential VoIP conference participants.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to Voice Over Internet (VoIP) protocols and architectures. More particularly, it relates to conferencing services using VoIP.

2. Background of the Related Art

Voice-Over-Internet Protocol (VOIP) is a technology that emulates a phone call, but instead of using a circuit based system such as the telephone network, utilizes packetized data transmission techniques most notably implemented in the Internet.

The use of VoIP technology is growing quickly. Given VoIP technology, there are at least three VoIP scenarios:

• • 1. A VoIP UA that is physically connected to a static data cable at a “home” address. For instance, an Analog Telephone Adapter (ATA) that is connected to the “home” data cable and uses traditional telephone devices.
  • 2. A VoIP UA that is physically connected to a data cable at a location different than its “home” address. For instance, a laptop computer device utilized away from home as a VoIP software telephone would be a VoIP ‘visitor’ device as described by this scenario.
  • 3. A VoIP UA that is wireleless, physically disconnected from any data cable.

In this situation, the VoIP UA connects to the VoIP service provider via either a wide-are wireless technology (e.g., cellular, PCS, WiMAX) or via a local-area wireless technology (e.g., Wireless Fidelity (WiFi), UWB, etc.) using a laptop computer or handheld device.

VoIP phone calls are routed to a VoIP voice gateway, from which they are passed on to their destination. A VoIP voice gateway or soft switch is a programmable network switch that can process the signaling for all types of packet protocols. Also known as a ‘media gateway controller,’ ‘call agent,’ or ‘call server,’ such devices are used by carriers that support converged communications services by integrating SS7 telephone signaling with packet networks. Softswitches can support, e.g., IP, DSL, ATM and frame relay.

VoIP telephone technology is quickly replacing conventional switched telephone technology. A location of a given VoIP device may be provisioned to be at a given geographic location, or queried from a home location register (HLR) in a mobile system.

With given VoIP technologies, a VoIP user must know the specific phone number of an individual, business, or other entity that they wish to call. There is no conventional technique for allowing a conference call between two or more VoIP users. In the Internet venue, users can find each other using a “chat room”, but the burden nevertheless remains on the user to search for, identify, and use a specific phone number or Universal Resource Identifier (URI) information to reach specific entities. This creates inefficiency and lack of flexibility with respect to the desire to establish a conference call, preventing VoIP users from managing their own communication needs and preferences. Generally, voice communication using VoIP technologies is limited to only point-to-point direct links between familiar or previously identified parties.

There is a need for an architecture and methodology that simplifies the complexity of conferencing VoIP calls.

SUMMARY OF THE INVENTION

In accordance with the principles of the present invention, a Voice Over Internet Protocol (VoIP) conference bridge comprises a conference bridge application active in a location addressed using Internet Protocol. A module determines a plurality of potential VoIP participants to the conference bridge based on pre-defined criteria. An invite module issues invites to each of the plurality of potential VoIP participants to the conference bridge. The conference bridge application has access to a plurality of Internet interfaces, to accept a respective plurality of potential VoIP participants to the conference bridge. The given conference is established between the accepted plurality of VoIP participants, with each of the plurality of VoIP participants satisfying the pre-defined criteria.

A method of conferencing Voice Over Internet Protocol (VOIP) voice communications devices in accordance with another aspect of the present invention comprises establishing at least one conference bridge. At least one criteria for participation in given conference bridge is determined, and an Invite Session IP message is issued to each of a plurality of potential VoIP participants defined by the at least one criteria.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exemplary architecture of a VoIP conference bridge application operating in a soft switch of a VoIP provider to provide VoIP location based conferencing, in accordance with the principles of the present invention.

FIG. 2 shows an exemplary message flow diagram for establishing a VoIP location based conference, in accordance with the principles of the present invention.

FIG. 3 shows a VoIP user originating an invitation to join a conference bridge in a VoIP soft switch, in a business to business or business to consumer scenario, in accordance with the principles of the present invention.

FIG. 4 shows exemplary signal/call flow for a VoIP user originating an invitation to join a conference bridge sent to other VoIP users as shown in FIG. 3.

FIG. 5 shows a VoIP user originating the transmission of a series of Invitations to join a conference bridge in a VoIP soft switch, in a peer to peer or consumer to consumer scenario, in accordance with the principles of the present invention.

FIG. 6 shows exemplary signal/call flow for a VoIP user originating an invitation to join a conference bridge sent to other VoIP users as shown in FIG. 5.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

A VoIP user from time to time might wish to initiate a conversation with other (known or unknown) VoIP users based on location and other shared attributes/criteria. The need may be for a single point-to-point type connection, or it may extend to the desire for a multi-user conference with other VoIP users.

Existing conferencing systems for putting VoIP users in touch with one another relies upon prior knowledge and contact information existing between the specified users. The present invention provides a way for VoIP users to use VoIP technology to form temporary or permanent “VoIP Communities” or VoIP conferences by initiating an interaction based on location and other shared attributes, supply/demand relationships, or other criteria.

Currently, there is no existing mechanism to create a voice link between VoIP communication devices based on the location of each VoIP user (and potentially other preferences or attributes). Existing VoIP technology does not address this problem for VoIP voice calls nor does it for any conference established based on location. For instance, while Internet text chat rooms provide a means of communication between party's, Internet text chat rooms do not utilize the user's location to find and invite available individuals/businesses/entities.

The present invention provides the ability for a VoIP user to utilize their own geographic position to narrow down or pinpoint known and even unknown potential VoIP third parties meeting the user's criteria based on their physical location to join in on a phone conference.

FIG. 1 shows an exemplary architecture of a VoIP conference bridge application operating in a VoIP soft switch of a VoIP provider to provide VoIP location based conferencing, in accordance with the principles of the present invention.

In particular, as shown in FIG. 1, a VoIP communications device 104 is serviced by their service provider's soft switch 102. A positioning center 106 provides location data upon request from the soft switch 102. Other VoIP users 110,112, 114 etc. are potential members of any given conference.

Conference bridges 100 are implemented on the VoIP soft switch 102 located, e.g., at the VoIP service provider's VoIP network.

While the VoIP soft switch 102 is preferably capable of being provisioned with as many VoIP conference bridges 100 as are required in any particular application, only one conference bridge 100 is shown in FIG. 1 for simplicity of explanation.

Also, while the conference bridge 100 is shown implemented in the soft switch 102, it can be embodied within another suitable network element having an Internet Protocol (IP) type connection (e.g., TCP/IP) with the initial user 104 as well as with the potential conferees 110, 112, 114.

The use of a conference bridge 100 eliminates the otherwise conventional requirement that the VoIP user 104 dial digits for a direct link with another specific VoIP communications device 110, 112 or 114. Instead, in accordance with the principles of the present invention, location information relating to the initial VoIP user 104 is passed to the VoIP conference bridge 100, either from the user's VoIP communication device 104 or from their respective location server 106. The location information is then compared by the VoIP soft switch 102 against other VoIP devices 110, 112, 114 etc. to find matching predetermined location-based criteria, e.g., within a geographic vicinity of the user's VoIP communication device 104.

The VoIP soft switch 102 makes use of the location information and other existing data or user input (e.g., existing preferences on file on the Soft Switch 102, user entry through the keypad of the communications device 104, or voice response). Based on the location and user input, the VoIP conference bridge 100 identifies potential other participants to be asked to join the conference currently established by the initial VoIP user 104 on the conference bridge 100, and outputs invites or requests 204 to join that conference 100 to the specific URLs, phone numbers and/or other identifying address information relating to VoIP communications equipment 110, 112, 114 of the potential other participants.

The soft switch 102 also maintains the attributes and rules from other communication devices 110, 112, 114 etc. for receiving conference bridge calls, as well as the fixed location (e.g., a place of business) or the ability to query for a current location (e.g., for mobile communication devices such as mobile phones) for each device. Based on this information, with or without other user input (e.g., to select or prioritize among a list of available third parties), the soft switch 102 invites one or more other communication devices 110, 112, 114, etc. to join the conference bridge. This creates a voice link between the first user 104 and the other third parties 110, 112, 114 without requiring the first user 104 to know the contact information or name of the third parties 110, 112, 114.

FIG. 2 shows an exemplary message flow diagram for establishing a VoIP location based conference, in accordance with the principles of the present invention.

In particular, as shown in FIG. 2, the initial VoIP user 104 sends a request for conference bridge call to the soft switch 102. Preferably the initial VoIP user 104 includes location information with the conference request call 201. However, as depicted in FIG. 1, location information can be obtained from an appropriate positioning server 106 if not available from the initial VoIP user 104.

Subsequent to the incoming conference call 201, suitable potential conferees are determined, and those that are within the geographic boundary pre-set or pre-provisioned into the conference bridge are invited with respective invite messages 204, 206.

In operation, the user's VoIP communication device 104 dials a pre-determined phone number (or URL) to initiate a conference bridge 100 on the relevant VoIP soft switch 102. Various phone numbers (or URL's) may be made available at the VoIP conference bridge 100, each corresponding to a respective VoIP conference bridge 100 each with its own pre-established profile of who will be invited once the conference bridge 100 is first entered by the initiating VoIP user 104.

For instance, one VoIP conference bridge 100 may be profiled to invite all other VoIP users within a geographic boundary of, e.g., 1 mile radius from a center point formed by the location of the initiating VoIP user 104. A geographic boundary need not be merely a distance range. For instance, a geographic boundary may comprise, e.g., the grounds of a college or schoolyard, a workplace, etc., or be as specific as those VoIP users within a given room (e.g., gym) at the college or schoolyard. Another VoIP conference bridge 100 with its own phone number (or URL) may correspond to invites to all other VoIP users 110, 112, 114 etc. currently located in, e.g., a given sports stadium.

The profiles used to identify the potential other VoIP conference participants may provide additional filtering characteristics beyond the location based information, e.g., other VoIP users who are contained not only within the pre-established geographic boundaries set for a given conference bridge 100, but also listed within a ‘conference buddy’ list pre-listed by the user. Thus, as a result, ‘buddies’ that a user has pre-listed that are within the sports stadium at the time of the user's call will be invited to join a VoIP conference bridge.

While use of location information is ideal in a preferred embodiment, another embodiment of the invention relates to conference invite messages being sent to those VoIP users meeting a particular filtering function (e.g., use of a buddy list).

FIG. 1 shows use of a VoIP positioning center (VPC) 106. The VoIP soft switch 102 may receive the user's location information either from each of the VoIP communication devices 104, 110, 112, 114 etc., or from the VPC 106.

The VoIP soft switch 102 preferably uses both the location information of the initiating VoIP user 104, together with any profile criteria set for a given conference bridge 100, to determine a list of potential other conferees to be sent INVITE messages inviting them to join the established VoIP conference bridge 100. The profile information for the conference bridge 100 is preferably either pre-established by the VoIP service provider (e.g., to set a geographic boundary within a sports stadium), and/or may be input by the initiating user through keypad entry or voice response on the communications device. Alternatively, profile information for a particular conference bridge may be pre-established via an appropriate web page and transmitted via the Internet to the soft switch 102 or other host gateway.

The VoIP soft switch 102 preferably also maintains the attributes and rules from other VoIP communication devices 110, 112, 114 for receiving conference bridge calls, as well as the fixed location (e.g., a place of business) or the ability to query for a current location (e.g., for mobile communication devices such as mobile phones) for each device. Based on this information, with or without other user input (e.g., to select or prioritize among a list of available third parties), the VoIP soft switch 102 invites one or more other VoIP communication devices 110, 112, 114, etc. to join the VoIP conference bridge 100. This creates a voice link between the first VoIP user 104 that initially called into the VoIP conference bridge 100, and the other potential, third party conferees 110, 112, 114, etc., without requiring the first VoIP user 104 to know the name or even the contact information of the other potential, third party conferees 110, 112, 114, etc.

Upon receipt of an invite to a VoIP conference bridge 204, 206, the potential other VoIP users 110, 112, 114, etc. are preferably notified similar to an incoming telephone call, e.g. with a ring signal, though it may be customized to be distinguished from the sound of an otherwise ordinary incoming phone call. For instance, a given unique phone tone may be activated upon receipt of an invite 204, 206 to a conference bridge 100.

In accordance with the principles of the present invention, the VoIP user(s) 110, 112, 114 receiving invitations to join a VoIP conference 100 may be provided with a filter that automatically rejects any/all invite requests not meeting their own specific criteria (e.g., maintained on their VoIP devices 110, 112, 114 themselves, though such filtering may alternatively be performed at a network level, e.g., at the VoIP soft switch 102 or other centralized location.

Benefits of the invention include that there is no effective limit to the number of participants in the conference VoIP call, there are no cold transfers of a call as VoIP invitees enter or leave the conference bridge 100, and there is the ability to continue the conference call even after the initial VoIP user 104 disconnects.

The present invention has particular applicability with any/all VoIP users, VoIP service providers, and/or even Public Safety Access Points (PSAPs).

FIG. 3 shows a VoIP user 104 originating an invitation to join a conference bridge 100 in a VoIP soft switch 102, in a business to business or business to consumer scenario, in accordance with the principles of the present invention.

In particular, as shown in FIG. 3, a VoIP user 104 initiates an invitation or request 204 based on certain pre-defined criteria for a service provider or a peer attribute. The VoIP service provider acquires the user's location information, either directly from the VoIP communications device 104 or by request to the LIS 106, and initiates a conference on the conference bridge 100. The conference bridge 100 issues invitations or notifications to one or more potential VoIP conferee users 110, 112, 114 etc. based on the location of the original user 104 and the specified criteria, by comparison to attribute or provider data for the other VoIP users 110, 112, 114 etc. The conference bridge 100 enables participation by multiple parties and does not depend on the participants' knowledge of or current access to each other's contact information, profile/attributes/business type, or location. In addition, VoIP users can elect when to receive notifications based on their current status (away, available, business hours, etc.) For instance, the VoIP user 104 would initiate a call to the conference bridge 100, thus initiating the sending of invitations or requests to potential conferees 110, 112, 114 etc. based on certain criteria (e.g., “tow truck drivers currently in Seattle”). Upon receipt of the initial call from the initiating VoIP user 104, the VoIP service provider initiates a conference bridge 100 and issues an INVITE or other notification to one or more VoIP users 110, 112, 114 etc. who have selected or subscribed to receive such conference notifications for this particular conference topic (as defined by its criteria). Subscriptions may be semi-permanent criteria for that particular conference bridge 100 (e.g., occupations or interests of the registered user of the relevant VoIP device) or temporary criteria (e.g., passengers on a specific airline flight, ticket agents with extra tickets for a specific event, etc.) The conference bridge 100 enables participation by multiple parties and does not depend on the participants' knowledge of or current access to each other's contact information. In addition, VoIP users can elect when to receive notifications based on their current status (e.g., away, available).

More sophisticated implementations of the invention include adaptation of the criteria for a given conference bridge 100 to correspond to a particular live auction. For instance, in such application, the matchmaking database 300 functions as an automated auction tool by accepting as criteria for the auction data such as the proposed cost of service, and then connect the lowest bidder of those potential bidders 110, 112, 114 to the conference bridge 100.

Preferably, the initiating VoIP user 104 is allowed to pre-define given criteria for the conference bridge 100, e.g., a maximum number of participants (e.g., the first 4 providers or peers who accept the conference invitation), or other criteria for choosing among multiple users (e.g., to select the VoIP user(s) 110, 112, 114 etc. whose location is closest to the initiating VoIP user 104 who initiated the conference invitation in the first place).

FIG. 4 shows exemplary signal/call flow for an initiating VoIP user 104 calling to establish a conference bridge 100, causing invitations to be transmitted to each potential VoIP conferee using IP protocol (e.g., TCP/IP) to join the conference bridge 100 as shown in FIG. 3. In response, each invited VoIP user 110, 112, 114 may accept or reject the invitation with an Accept or Reject message transmitted via Internet Protocol back to the VoIP soft switch 102 that transmitted the initial invite messages 204, 206.

Offline activity also occurs, separate from the call flow, e.g., to update location data (be it permanent or temporary) and criteria or attributes for the conference bridge 200 itself. Availability data may also be maintained and updated offline, e.g., relating to pre-defined times for the conference bridge 100 to be established, and/or to the current status of the conference bridge 100.

FIG. 5 shows a VoIP user 104 originating the transmission of a series of Invitations 504 to join a conference bridge 100 in a VoIP soft switch 102, in a peer to peer or consumer to consumer scenario, in accordance with the principles of the present invention.

In particular, as shown in FIG. 5, the VoIP user 104 can call a conference bridge 100 and provide particular, customized criteria for the conference. In a peer-to-peer scenario as shown in FIG. 5, the VoIP user 104 issues a peer-to-peer request 550 such as a call searching for tickets to a specific public event (e.g., “Falcons Tickets”), searching for others with a similar hobby or interest (e.g., “Chess Players”), matchmaking services forming a personal add (e.g., “Male 30-35”), etc.

In the disclosed embodiment, the peer-to-peer conference is initiated by a call by an initiating VoIP user 104. The conference bridge 100 may be pre-established with pre-determined criteria, and the initiating VoIP user 104 merely calls the appropriate conference bridge 100. In such case, the VoIP service provider may establish network-wide criteria itself, or may allow customized conference bridges as a service to their subscribers. Alternatively, the criteria for the conference bridge may be established by the initiating VoIP user 104. The criteria may be transmitted to the soft switch to establish the relevant conference bridge 100 preferably with data contained within the call from the initiating VoIP user 104.

The peer attributes and desired geographical boundaries of the conference are maintained in a matchmaking database 500 in communication with the VoIP soft switch 102 or other gateway that hosts the conference bridge 100.

The VoIP soft switch 102 issues a Peer Request 504 with location data to any/all VoIP users 110, 112 and/or 114 fitting the criteria for the conference. In response, those VoIP users 110, 112 and/or 114 who accept entry into the conference (e.g., by activating an ‘Accept’ button on the VoIP communications device), return an Accept message 505 to the inviting VoIP soft switch 102. Those VoIP users 110, 112 and/or 114 that don't accept the Invite (either by activating a ‘Reject’ button on the VoIP communications device, or simply by not responding to the Invite message 204 within a given period of time) return a Reject message 505 to the inviting VoIP soft switch 102.

The invited VoIP users 110, 112, 114 may include a filter allowing through only acceptable Invite messages based on criteria established by or on the receiving VoIP users 110,112, 114.

FIG. 6 shows exemplary signal/call flow for a VoIP user originating an invitation to join a conference bridge sent to other VoIP users as shown in FIG. 5.

In particular, the peer-to-peer request 550 issued by the VoIP user 104 is depicted in FIG. 6, as are the respective Invite messages 504 and Accept or Reject messages 505 from each of the invited VoIP users 110, 112, 114.

The present invention allows VoIP users to find their most appropriate conferees, provider or peer match with minimal user interaction. This is particularly helpful for mobile VoIP users (e.g., while driving, walking, etc.) Moreover, there is no effective limit to the number of participants in the conference call (within network hardware limits of the conference bridge itself). There is also no risk of cold transfers of a VoIP telephone call as participants aren't handled in point-to-point connections that are transferred but rather join or exit an established conference at will. Furthermore, participants in the conference call can continue in the conference even after the initial user disconnects.

Potential markets for the present invention include VoIP service providers who may implement the inventive VoIP multi-user conferencing as a value added services for users. Other uses of the invention include consumer and business VoIP users with respect to commercial, government, educational activities, and Public Safety Access Points (PSAPs), to name a few.

VoIP location based conferencing in accordance with the principles of the present invention has particular applicability with any/all VoIP users and VoIP service providers.

While the invention has been described with reference to the exemplary embodiments thereof, those skilled in the art will be able to make various modifications to the described embodiments of the invention without departing from the true spirit and scope of the invention.

Claims

1. A Voice Over Internet Protocol (VoIP) conference bridge, comprising: a conference bridge active in a location addressed using Internet Protocol;a configuration module to receive an initiating VoIP device's custom conference criteria from an initiating VoIP device, said initiating VoIP device's custom conference criteria being a plurality of text characters typed on an initiating VoIP device to initiate establishment of said conference bridge;a module to determine a plurality of potential VoIP devices to connect to said conference bridge based on said initiating VoIP device's custom conference criteria;an invite module to issue an invite to each of said plurality of potential VoIP devices to connect to said conference bridge, said invite based on said initiating VoIP device's custom conference criteria; anda plurality of Internet interfaces to said conference bridge, to accept a respective plurality of potential VoIP devices to connect to said conference bridge.

2. The Voice Over Internet Protocol (VoIP) conference bridge according to claim 1, wherein: said issued invite is transmitted using Internet Protocol (IP).

3. The Voice Over Internet Protocol (VoIP) conference bridge according to claim 2, wherein: said issued invite is transmitted over an Internet.

4. A method of conferencing Voice Over Internet Protocol (VoIP) voice communications devices, comprising: establishing at least one conference bridge;receiving an initiating VoIP device's custom conference criteria from an initiating VoIP device, said initiating VoIP device's custom conference criteria being a plurality of text characters typed on an initiating VoIP device to initiate establishment of said conference bridge; andissuing an invite message to each of a plurality of potential VoIP devices, said invite based on said initiating VoIP device's custom conference criteria.

5. The method of conferencing Voice Over Internet Protocol (VoIP) voice communications devices according to claim 4, wherein: said custom conference criteria includes location-based information relating to a location of each of said plurality of potential VoIP devices.

6. The method of conferencing Voice Over Internet Protocol (VoIP) voice communications devices according to claim 4, wherein: a geographic boundary corresponding to said custom conference criteria is moveable during an active conference established on said at least one conference bridge.

7. The method of conferencing Voice Over Internet Protocol (VoIP) voice communications devices according to claim 6, wherein: said geographic boundary corresponds to devices on a mass transit vehicle.

8. The method of conferencing Voice Over Internet Protocol (VoIP) voice communications devices according to claim 7, wherein: said mass transit vehicle is an airplane.

9. The method of conferencing Voice Over Internet Protocol (VoIP) voice communications devices according to claim 7, wherein: said mass transit vehicle is a train.

10. The method of conferencing Voice Over Internet Protocol (VoIP) voice communications device according to claim 4, wherein: said conference bridge is established on a soft switch.

11. The method of conferencing Voice Over Internet Protocol (VoIP) voice communications device according to claim 10, wherein: said soft switch is located in a VoIP service provider's network.

12. Apparatus for conferencing Voice Over Internet Protocol (VoIP) voice communications devices, comprising: means for establishing at least one conference bridge;means for receiving an initiating VoIP device's custom conference criteria from an initiating VoIP device, said initiating VoIP device's custom conference criteria being a plurality of text characters typed on an initiating VoIP device to initiate establishment of said conference bridge; andmeans for issuing an invite message to each of a plurality of potential VoIP devices, said invite based on said initiating VoIP device's custom conference criteria.

13. The apparatus for conferencing Voice Over Internet Protocol (VoIP) voice communications devices according to claim 12, wherein: said custom conference criteria includes location-based information relating to a location of each of said plurality of potential VoIP devices.

14. The apparatus for conferencing Voice Over Internet Protocol (VoIP) voice communications devices according to claim 12, wherein: a geographic boundary corresponding to said custom conference criteria is moveable during an active conference established on said at least one conference bridge.

15. The apparatus for conferencing Voice Over Internet Protocol (VoIP) voice communications devices according to claim 14, wherein: said geographic boundary corresponds to devices on a mass transit vehicle.

16. The apparatus for conferencing Voice Over Internet Protocol (VoIP) voice communications devices according to claim 15, wherein: said mass transit vehicle is an airplane.

17. The apparatus for conferencing Voice Over Internet Protocol (VoIP) voice communications devices according to claim 16, wherein: said mass transit vehicle is a train.

18. The apparatus for conferencing Voice Over Internet Protocol (VoIP) voice communications device according to claim 12, wherein: said conference bridge is established on a soft switch.

19. The apparatus for conferencing Voice Over Internet Protocol (VoIP) voice communications device according to claim 18, wherein; said soft switch is located in a VoIP service provider's network.