HK1115027A - System and method for forming ad-hoc location-based multicast group - Google Patents

Abstract

A system, method, and media for providing group communication services to an ad-hoc group formed according to vicinity with other users of communication devices in a communication system. Communicating among a communication group of a plurality of wireless communication devices in a communication system includes forming the communication group including transmitting an invitation including group membership location criteria to join the communication group to the plurality of wireless communication devices. The group membership location criteria is evaluated at each of the plurality of wireless communication devices receiving the invitation and the communication group is formed by ones of the plurality of wireless communication devices that meet the group membership location criteria. Permission to transmit to others of the plurality of wireless communication devices of the communication group is granted to one of the wireless communication devices of the communication group.

Description

System and method for forming location-specific multicast groups

Claiming priority according to 35 U.S.C § 119

This patent application claims provisional application No. 60/668,440 entitled "Forming a user location based Push-to-Talk group and Granting a remote Floor (Forming Push-to-Talk Groups based on location of Users, and granted Floor removal)" prior to 4.4.2005, which is assigned to the assignee of the present application and is hereby expressly incorporated herein by reference.

Technical Field

The present invention relates to point-to-multipoint communication systems. More particularly, the present invention relates to a method and apparatus for forming a location-based ad-hoc multicast group.

Background

In emergency communication situations, such as those caused by natural or man-made disasters, it is important to be able to form effective communications so that a maximum number of affected people have access to limited resources (e.g., wireless telecommunications channels). In the event of a wide range of disasters, such as earthquakes or hurricanes, the communication resources can be subjected to unusually high loads. A wireless service designed for fast, efficient, one-to-one or one-to-many (group) communication has existed in various forms for many years. Broadly speaking, these services have been half-duplex, where a user presses a "push-to-talk" (PTT) button on their phone/wireless phone to initiate a conversation. In some embodiments, or in a screening type system, where communication occurs via some type of server, pressing a button (i.e., any key of the user's radio) will indicate the user's request for the "floor". If the floor or permission to talk is granted, the user typically talks for a few seconds, then he releases his PTT button and other talkers may request the floor. Communication is typically from one talker to a group of listeners, but may be one-to-one. These services have conventionally been used in applications where one person, a "dispatcher," needs to communicate with a group of people (e.g., field service personnel or taxi drivers), which is the source of the "dispatch" name for the service.

The main feature of these services is the rapidity and spontaneity of communication, which is typically initiated by simply pressing the PTT button, without going through the typical dialing and ringing sequence. Communication in this type of service is typically extremely short, with individual conversation "bursts" typically on the order of seconds and "sessions" possibly lasting one minute or less.

Since communications occur in "bursts" or small sessions, the information communicated is generally recapitulated and results in an efficient method of communication for emergency conditions in which communication resources may be limited. Thus, communications occurring in "bursts" only require that communication resources be temporarily allocated to a given user or group of users so that the resources are available for use by other users at different times. It is known that using communication "bursts" rather than dedicated channels results in more efficient use of resources, since many dedicated resource sessions contain a lot of transmitted silence. In addition, half-duplex sessions do not impose a resource burden on the part of the session (listening or talking) that is not used at the time.

As mentioned herein, communication may be configured to occur between group members. In the scheduling model, communication between endpoints occurs in virtual groups, where the voice of one "talker" is broadcast or (more specifically) multicast to one or more "listeners". A single instance of this type of communication is commonly referred to as a dispatch call or call only. A call is an instantiation of a group that defines the characteristics of a call and is essentially a member list with some associated information, such as a group name or group id. The member list is a list of one or more users invited to participate in the call.

There is a need for emergency response teams that establish communication with any and all users in an area affected by a wide range of natural disasters without over-stressing the available telecommunication resources and that assign users in the area emergency assistance information specific to the area in which the user is located.

Disclosure of Invention

A system and method for providing group communication services to an ad-hoc group formed according to proximity to other communication device users in a communication system is provided. In one embodiment of the present invention, a method to communicate between a plurality of wireless communication devices of a communication group in a communication system includes forming the communication group including transmitting an invitation including group membership location criteria to join the communication group to the plurality of wireless communication devices. The group membership location criteria is evaluated at each of the plurality of wireless communication devices that received the invitation, and the communication group is formed by the ones of the plurality of wireless communication devices that satisfy the group membership location criteria. Granting permission to transmit to other ones of the plurality of wireless communication devices of the communication group to one of the wireless communication devices of the communication group.

In another embodiment of the present invention, a wireless communication device comprises a method for communicating in a communication group of a plurality of wireless communication devices of a communication system. The wireless communication device joins a communication group in response to receiving an invitation to join the communication group for a plurality of wireless communication devices, the invitation including group membership location criteria. The wireless communication device evaluates the group member location criteria and joins the communication group when included in the criteria. The wireless communication device transmits to other devices of the plurality of wireless communication devices of the communication group upon receiving permission to transmit in the communication system.

In another embodiment of the present invention, a wireless communication system includes a communication manager including a scheduler interface configured to generate an invitation to join a communication group, wherein the invitation includes group membership location criteria. The communication manager is further configured to grant permission to one of the groups to transmit to other devices in the communication group. The wireless communication system further comprises: a base station configured to transmit an invitation to join the communication group; and a plurality of wireless communication devices configured to evaluate a group membership location criterion at each of the plurality of wireless communication devices receiving the invitation. The device of the plurality of wireless communication devices that satisfies the group membership location criteria is further configured to accept the invitation to join the communication group, and one of the plurality of wireless communication devices is further configured to receive permission to transmit and transmit to the other devices of the communication group in response thereto.

In yet another embodiment of the present invention, a communication device for communicating among a plurality of wireless communication devices of a communication group includes means for joining the communication group, the device including: receiving means for receiving an invitation to the plurality of wireless communication devices to join the communication group, the invitation including group membership location criteria; and evaluating means for evaluating group membership location criteria at each of the plurality of wireless communication devices that received the invitation. The wireless communication device further comprises: joining means for joining the communication group; and transmitting means for transmitting to other ones of the plurality of wireless communication devices of the communication group upon receiving permission to transmit to the other ones of the plurality of wireless communication devices of the communication group in the communication system.

In yet another embodiment of the present invention, a computer-readable medium is provided that comprises a method of communicating between a communication group of a plurality of wireless communication devices in a communication system. The method of communicating between a communication group of a plurality of wireless communication devices in a communication system includes forming the communication group including transmitting an invitation including group membership location criteria to join the communication group to the plurality of wireless communication devices. Group membership location criteria is evaluated at each of a plurality of wireless communication devices receiving the invitation, and the communication group is formed by ones of the plurality of wireless communication devices that satisfy the group membership location criteria. Granting permission to transmit to other ones of the plurality of wireless communication devices of the communication group to one of the wireless communication devices of the communication group.

In yet another embodiment of the present invention, a computer-readable medium is provided that comprises a method of communicating in a communication group of a plurality of wireless communication devices in a communication system. The method comprises the following steps: joining the communication group in response to receiving an invitation to join the communication group to the plurality of wireless communication devices, the invitation including group membership location criteria. The method further comprises: the group membership location criteria is evaluated and joined to the communication group when included in the criteria, and transmitted to other ones of the plurality of wireless communication devices of the communication group upon receipt of permission to transmit in the communication system.

Drawings

Fig. 1 illustrates a typical prior art wireless communication system 100;

fig. 2 illustrates a wireless communication system configured for group communication in accordance with an embodiment of the present invention;

fig. 3 illustrates a representative implementation of group communications in accordance with an embodiment of the invention;

FIG. 4 illustrates the formation of ad-hoc groups formed based on proximity to a specified location, according to an embodiment of the present invention;

fig. 5 is a flow diagram illustrating a representative floor control method in accordance with one or more embodiments of the invention;

fig. 6 is a flow diagram illustrating a group member's remote floor request and grant to the group member in accordance with an embodiment of the present invention; and

fig. 7 is a flow diagram illustrating remotely releasing a floor in a communication group according to an embodiment of the present invention.

Detailed Description

The present invention is a system and method for providing group communication services to an ad-hoc group formed according to proximity to other Communication Device (CD) users or according to proximity to a given location in an existing communication system. Forming communication groups based on proximity to other users or based on user locations defined within a given area may allow for more efficient or appropriate deployment of emergency services during an emergency. In general, a set of neighboring CDs are not subscribed to a particular communication group. Various embodiments of the present invention provide a method and system for identification, grouping, and usage rules of limited communication resources available to neighboring CDs.

The invitation to join a particular group is broadcast widely using membership criteria. The inviting recipient CD determines whether it is included in the membership criteria. The CD included in the membership criteria responds to the invitation with an acceptance invitation. In other embodiments of the present invention, the "floor" or talk burst is managed by a dispatcher to manage large numbers of talk requests, prioritize talkers, assist failed talkers, and release talkers who may not be able to relinquish talk bursts.

Although the teachings of the present invention are described herein with reference to a wireless CDMA communication system, it should be appreciated that the present invention may be used in any wireless communication system, including GSM systems, AMPS systems, TDMA systems, satellite communication systems, and other communication systems. In addition, the present invention is not limited to a wireless communication system. It may be used for wired telephones, paging devices, portable or desktop computers, digital cameras, video cameras, and the like. Furthermore, it should be understood that the present invention is applicable to both real-time data, such as audio and video data (including voice data), and time-independent data, such as computer files, e-mails, and the like. Moreover, the terms "conversation," "speaking," and the like, as used throughout are exemplary only, and encompass all forms of media including, but not limited to, voice, conversation, data, video, and other signaling techniques.

A common form of group communication is known as "push-to-talk", commonly abbreviated PTT. The characteristics of this communication method include a conversation over a semi-multiplexed communication line by pressing a button to allow transmission of voice communications and releasing the button to allow reception of voice communications. Such PTT features are being implemented in current Communication Devices (CDs), such as mobile terminals, mobile phones, handsets (handsets), wireless devices, etc., allowing CDs to act as digital two-way radios (e.g., walkie-talkies) in push-to-talk operation. One person can talk at a time by pressing the PTT button, while one or several others can listen immediately. Some PTT schemes are based on 2.5G packet-switched networks (e.g., CDMA, GPRS, etc.) and use specific protocols, namely SIP (session initiation protocol) and RTP (real-time transport protocol). These particular versions of PTT are referred to as "push-to-talk over cellular networks" (or push-to-talk over cellular), generally referred to simply as PoC.

In expanding cellular communication networks to accommodate other and various types of data, such as voice, image, audio, video, multimedia, and so on, various internet access technologies are utilized. An example would be Internet Protocol (IP), which is a data-oriented protocol used by source and destination hosts for communicating over a packet-switched network, such as the internet, and examples include IPv4, IPv6, and the like.

Among the various features of PTT, including a particular type of PTT known as PoC, floor control procedures with respect to the server are important for efficient group communications. In particular, the server can be considered a central point that grants the "floor" to PTT users who want to talk to a communication or talk group. That is, the user may "get the floor" and talk to other users who may only listen during that time.

When multiple users want to get the floor (to speak to other users) by sending transmission requests (e.g., floor requests, talk burst requests, etc.) accordingly, priorities should be assigned so that the users can talk in turn by considering whether their transmission requests have been granted or denied. For example, priority may be assigned on a first come first served basis. For each transmission request from each client, the server may grant or deny each request based on the communication environment or other factors thereof. Talk burst allocation may also be referred to as obtaining the right to talk (or the right to talk) or obtaining permission to transmit (access request). Users granted the right to talk are referred to as having granted the "floor" or granting the "talk burst," and these expressions may be used interactively.

In various embodiments of the present invention, a primary privilege to manage talk spurts is given to a particular user (e.g., a dispatcher), and the server controls talk spurts according to a talk management scheme applicable to the situation or a particular time.

Fig. 1 illustrates a typical prior art wireless communication system 100 that is incapable of implementing the formation and control of ad-hoc group communications, otherwise known as point-to-multipoint communications or push-to-talk communications. CDs 102, 104, and 106 represent 3 of a large number of wireless telephones distributed throughout a small geographic area 118 serviced by communication system 100. CDs 102, 104, and 106 generally transmit and receive communication signals with base stations 108 and/or 110 depending on their proximity to each base station. In a typical wireless communication system, there are many base stations available to support the large number of CDs in communication system 100.

The present invention is illustrated herein in the functional block diagram format shown in fig. 2. A group communication system 200, alternatively referred to as a push-to-talk system, a push-to-talk over cellular system (PoC), a group or network broadcast system, a dispatch system, or a point-to-multipoint communication system, is shown. A defining feature of such communication systems is that typically only one user can transmit information to other users at any given time. In the group communication system 200, a group of communication device users, individually referred to as group or network members, communicate with each other using a wireless Communication Device (CD) assigned to each group or network member.

The term "group" or "network" represents a collection of communication device users that are privileged to communicate with each other. In general, the central database contains information identifying the members of each particular group. More than one group may operate in the same communication system. For example, a first group may be defined as having 10 members and a second group may be defined as having 20 members. The 10 members of the first group may communicate with each other but generally not with the members of the second group, although in principle an individual user may be a member of more than one group. In other cases, members of different groups can monitor communications between members of more than one group, but can only transmit information to members within their own group. In yet another scenario, a group may not be predefined, but may typically be formed in a particular manner by users who invite other users to a particular group one at a time. Groups formed in this manner are disbanded upon termination of a particular communication session.

The group members communicate with each other using assigned communication devices, shown as Communication Devices (CDs) 202, 204, and 206. In this example, CDs 202, 204 and 206 are terrestrial wireless telephones. In other embodiments, the various CDs may include wireless video cameras, still cameras, audio devices such as music recorders or players, laptop or desktop computers, or paging devices. In another embodiment, at least one CD comprises a combination of the preceding embodiments. For example, CD 202 may comprise a wireless terrestrial telephone equipped with a video camera and display. Throughout the following discussion, reference to an individual CD may be expressed as CD 202. It should be understood, however, that references to CD 202 are not intended to limit the discussion to terrestrial wireless telephones. In general, discussions related to CD 202 will apply equally to other types of CDs as well.

In general, a CD may be a terrestrial wireless telephone that is capable of converting media (typically human speech) into data packets suitable for transmission over a data network. CDs typically include an antenna, a display, keys, a speaker, a headset, and optionally a push-to-talk (PTT) switch. The display and keys are collectively referred to herein as a user interface. In an alternative embodiment, a CD may use an existing key as a push-to-talk switch when in a push-to-talk communication mode instead of using a dedicated push-to-talk switch.

The CD further includes a legacy transmitter and receiver for compatibly interacting in a wireless communication system. CDs may be configured to operate in one or more modes or a single communication mode. By way of example, and not limitation, one mode of operation may comprise a standard audio call mode from a CD to a base station. This mode is used to make typical point-to-point telephone calls using a given technology of the associated communication system. For example, the voice service mode of a CD may involve point-to-point audio communication using CDMA telecommunication standards promulgated by the Telecommunications Industry Association (Telecommunications Industry Association).

In the group communication system of fig. 2, unique transmission privileges are defined that generally allow only a single user to transmit information to other group members at any given time. The transmission privilege is granted or denied to the requesting group member depending on whether the transmission privilege is currently assigned to another group member when the request is received. The process of granting and denying transmission requests is referred to as arbitration. Another common term for such arbitration is also referred to as "requesting the floor," granting the floor, "and" denying the floor. Other arbitration schemes evaluate factors such as the priority level assigned to each CD to determine whether to grant a transmission privilege or "floor" to the requesting group member.

To join a group communication, CDs 202, 204, and 206 are each equipped with a means for requesting transmission privileges from Communication Manager (CM)218, as explained in more detail below. CM218 manages the real-time and administrative operations of the group including PTT request arbitration (e.g., floor request/grant/deny), maintenance, and distribution and registration lists of the group membership, call setup and tear down of necessary system and communication resources, and overall control of the group or network state.

CM218 maintains a list of defined groups, provided that privileges are provided by service providers, and is designed for remote management by communication system service providers, group members, or both. CM218 receives the group definition through external management interface 226. Group members may request administrative actions through their service provider or through requests to the hypervisor interface 226.

In one embodiment of the present invention, the supervisor interface 226 provides a scheduler for requesting that users located in a particular neighborhood or area be formed into a particular communication group and for regulating communications over the group communication system 200 based on various criteria. The dispatcher through hypervisor interface 226 may manage large numbers of talk requests, prioritize speakers, assist disabled speakers, and release speakers that may not be able to relinquish permission to talk.

In one embodiment of the invention, a CD is configured to request transmission privileges by initiating or activating a push-to-talk (PTT) key or switch. When a user of a CD in communication system 200 wants to transmit information to other group members, a push-to-talk switch located on the CD is depressed, sending a request (e.g., a floor request) to gain transmission privileges from communication manager 218. If no transmission privilege is currently assigned to other group members and the floor is not prohibited or denied as a result of the valid communication standard, the requesting user is granted the transmission privilege and notified by an audible, visual, or tactile alert through the CD. After the requesting user is granted the transmission privilege, information may then be transmitted from the user to other group members.

In one embodiment of the invention, each wireless group member establishes a forward link and a reverse link with one or more base stations 216. The former is used to describe the communication channel from the base station 216 and the latter is used to describe the communication channel from the CD to the base station 216. Voice and/or data (as well as other media forms) are converted into data packets using CDs, where the data packets are compatible with a particular data network 214 through which communications with other users occur.

In one embodiment, the data network 214 is the internet. In another embodiment, a dedicated forward channel is established in each communication system (i.e., terrestrial and satellite communication systems) to broadcast information from each group member to the other group members. Each group member receives communications from other group members over a common channel.

In another embodiment, a dedicated reverse link is established in each communication system to communicate information to CM 218. Finally, a combination of the above schemes may be used, such as establishing a common forward broadcast channel but requiring wireless CDs to transmit information to CM218 over individual reverse links assigned to each CD.

When a first group member wants to transmit information to other members of the group, the first group member requests a transmission privilege by pressing a push-to-talk key on its CD, which generates a request (e.g., floor request) formatted for transmission over the data network 214. In the case of CDs 202, 204, and 206, the request is transmitted wirelessly to one or more base stations 216. The Mobile Switching Center (MSC)220 includes a well-known interworking function (IWF) (not shown) to handle data packets (including the request) between the MSC 220 and the data network 214. MSC 220 is typically a packet switch designed to route data packets according to the Internet Protocol (IP).

If no other member currently holds the transmission privilege at the time CM218 receives the transmission privilege request, CM218 transmits a message (e.g., a floor grant) to the requesting group member informing that the transmission privilege has been granted to the requesting group member. Audio, visual, or other information is then transmitted from the first group member to the other group members by sending the information to CM218 using one of the transmission paths described above. In one embodiment, CM218 then provides the information to the group members by copying the information and sending each copy to the group members. If a single propagation channel is used, the information need only be replicated once for each broadcast channel used. If some but not all group members can listen to the broadcast channel, the information is replicated once for that user and once for every other user that cannot listen on the broadcast channel. This concept can be extended for the case of multiple broadcast channels.

In an alternative embodiment, CM218 is incorporated in MSC 220 such that data packets from supporting base stations are routed directly to CM218 without being routed over data network 214. In this embodiment, CM218 is still connected to data network 214 so that other communication systems and devices may join the group communication.

CM218 maintains one or more databases for managing information relating to individual group members and each defined net. For example, for each group member, one database may include a username, account name, telephone number or dial-up number, a mobile identification number associated with the member's CD, assigned to the CD, the status of the current member in the group, such as whether the member is actively joining the group, a data telephone number associated with the CD, an IP address associated with the CD, and an indication of which groups the member is authorized to communicate with. Other relevant types of information may also be stored by the data with reference to each group member.

The interfaces of the system are divided into functional and physical interfaces. The physical interface is not unique to group communication system 200 and consists of existing wireless air interfaces, wireless service options, and business data interconnection standards. Higher layer functional interfaces, especially at the application layer, are unique to group communication services.

In one embodiment of a group communication system, at the application layer, a representative embodiment of the present invention operates on an internet-based protocol as shown in fig. 3. Of course, other protocols may be used instead. Communications between CM218 and CDs 202, 204, and 206 occur within these protocols. CDs can find, join, leave, and learn about various groups using the well-known signaling protocol, Session Initiation Protocol (SIP), used in the telecommunications industry. Audio (collectively referred to herein as media) including voice, video or data is separately distributed via a third encapsulation. In the example shown in FIG. 3, CD 202 is currently "on the floor," i.e., a transmission privilege or permission to transmit media to the group. A "floor control" request is a request for a transfer privilege. While CD 202 holds the transmission privilege, the remaining group members 204, 206 are defined as listeners and accordingly do not have permission to transmit media to the group. In general, any CD may send media signaling or SIP signaling traffic at any time, regardless of whether it holds transmission privileges.

CM218 communicates with CDs joining in group communications via transport and group communication application layer protocols. These communications include application signaling (PTT transmission privilege requests, network registrations, etc.) as well as real-time voice media packet streams distributed by CM 218. All real-time media is distributed via CM218 and the dynamic RTP/UDP/IP interface on the CD. If CRTP header compression is not available, the real-time media is encapsulated directly within UDP/IP packets or datagrams. All real-time signaling occurs through CM218 and the dynamic UDP/IP interface on the CD. Other signaling may occur via predetermined data protocol interfaces, such as TCP/IP, using the well-known Session Initiation Protocol (SIP) between CM218 and a CD, an application layer Call signaling protocol designed to support Internet telephony. Although the present representative embodiment utilizes SIP for signaling, other protocols providing compatible signaling known to those skilled in the art may be utilized.

CM218 may support other administrative type interfaces for creating groups, configuring specified privileges to schedulers, for example, and these administrative type interfaces may also be based on IP signaling techniques. CM218 may provide an administrative interface that provides CM users with administrative access, networking, and administrative databases and associated parameters using hypertext markup language (HTML) semantics. Alternatively, a language other than HTML may be used. In one embodiment, the interface operates over TCP/IP. There may also be a second network interface that supports administrative functions. This second administrative interface supports high volume real-time delivery of administrative information including membership lists and network status reports to Java or similar client administrative applications.

A representative group communication system has been described herein with reference to fig. 1-3. To facilitate formation of a particular user group when included in the location-based membership criteria, the group communication system is further configured to cooperatively facilitate formation of a group based on user location and management communication permissions according to available principles of limited communication resources, such as management of large volume talk requests, prioritization of talkers, assistance to void talkers, and relinquishing talk permissions of users.

There are certain unique security aspects associated with forming ad-hoc groups in a cooperative and automated manner. Thus, the privilege to initiate the formation of such a group is controlled by a strict security program. Only privileged personnel are allowed to access scheduler 226 and the control link between access scheduler 226 and CM 218. CM218 in turn controls the formation of specific user groups when included in location-based membership standards, so the security aspects of such formation will only be uniquely driven by franchises and trained personnel (e.g., police, emergency maintenance, fire department personnel, etc.) through secure access to CM218 functionality with respect to such an application. In addition to physical security, remote access to critical facilities is also directed (e.g., a flag can be set on a paging channel) using security keys and authorization certificates in accordance with techniques well known to those skilled in the art.

Fig. 4 illustrates the formation of an ad-hoc group in response to an emergency notification, wherein the group is formed based on proximity to a specified location. Scheduler 400 identifies the occurrence or occurrence of events or conditions in which communications between neighboring users may benefit. The scheduler 400 requests 402 setting of an emergency flag in a generally monitored channel ("common channel"), such as a paging or broadcast channel regularly monitored by CDs located in the area of interest.

In another embodiment of the invention, scheduler 400 also specifies group membership location criteria, such as an area or location criteria that defines the inclusion boundaries of users invited to join the group. By way of example and not limitation, representative location criteria may include a location center point and acceptable radius, perimeter location, serving base station identifier, and other location-based identifiers known to those skilled in the art.

The request from scheduler 400, including any location criteria, is sent to CM 404 for processing and scheduling in subsequent transmissions. CM 404 directs 406 MSC/BS_N408 are being assigned by a designated base station (designated BS herein)_N408) Transmitting a set of emergency flags on common channels in at least one region of service, wherein the BS_N408 serve the area around the user's desired location contained within the particular group.

MSC/BS_N408 transmit (410) the set of emergency flags in a regularly monitored common channel by CDs 412, 414, 416, etc. At the same time, MSC/BS_N408 transmit (420) to all recipient CDs, as previously directed by the CM 404, a full or undifferentiated or universal invitation to join the group, wherein the CD accepts the invitation conditional on qualifying it according to the location criteria also transmitted in the full undifferentiated invitation.

CDs 412, 414, 416 monitor (422, 424, 426) respectively by MSC/BS_N408, and while monitoring the common channel, the recipient CD 412, 414, 416 recognizes the set of emergency flags and responds appropriately by effectively monitoring (428, 430, 432) the designated or well-known emergency broadcast channel for further information. The CDs 412, 414, 416 receive a totally undifferentiated invitation to join the group, with the right to accept the invitation conditioned on qualifying the CD based on location criteria also transmitted with the totally undifferentiated invitation in an emergency broadcast channel.

The CDs 412, 414, 416 calculate their locations and evaluate (434, 436, 438) their locations according to group member location criteria (examples of which include specified location criteria) to determine eligibility to accept invitations to join the group. By way of example, and not limitation, FIG. 4 illustrates a CD₁412 qualifies to join the group and therefore accepts 440 the invitation and forwards it back to the scheduler 400 through the CM 404. Scheduler 400 modifies 442 the group list to associate CDs₁412 includes being a determined member of the group. Similarly, FIG. 4 also illustrates CDs₂414 qualifies to join the group and accordingly accepts (444) the invitation and forwards the invitation back to the scheduler 400 through the CM 404. Scheduler 400 modifies 446 the group list to associate CDs₂414 include being a determined member of the group. Since more CDs can

Fig. 5 is a flow diagram illustrating a representative floor control method in accordance with one or more embodiments of the invention. Conducting group communications during various conditions in which resources are limited may benefit from implementation of one or more access control methods. Fig. 5 illustrates various access control restrictions that may be imposed on members of a group to provide more efficient use of available communication resources. Once a specific group has been formed through the generalized wide-area invitation process described above, the CD is designated_NThe floor may be requested (502) according to a floor request procedure, such procedures described herein or according to other floor request procedures are well known to those skilled in the art. The determination 504 identifies the current or scheduled availability of communication resources and denies (506) the CD when the floor is not available_NIs requested for the floor.

When determination 504 identifies that the floor is available, determination 508 identifies a potentially valid floor-authority criteria, and when the floor-authority criteria are valid, determination 510 then identifies the CD_NWhether or not restricted. If CD_NIf restricted, rejecting the CD_N(506) Is requested for the floor. If CD_NNot restricted or if the floor authority is not valid, then a determination 512 identifies the floorWhether the floor prioritization criteria are in effect and granting (520) the floor request when the floor priority is not in effect. Evaluating (514) the CD using a dispatcher priority table 516 when floor prioritization criteria are in effect_NTo determine CD_NWhether the access request of (1) is prioritized. The determination 518 identifies any priority and rejects (506) the CD if the CDN priority is low_NOr if the CD is a CD_NGranting 520 CD higher priority_NIs requested for the floor.

Fig. 6 is a flow diagram illustrating the ability of a group member to remotely request and grant a floor to the group member. Various conditions may occur that prohibit CD users from communicating in the group. Representative conditions may include the user's eligibility or the user's ability to participate in the physical steps necessary to request the floor (e.g., activating a PTT button on a CD). Whether such disablement is pre-existing in a disaster event or triggered by an event, the present embodiments of the invention facilitate communication between the dispatcher and the CD user.

In the present embodiment of the invention, the scheduler acts as a CD by requesting (602) the floor according to a floor request procedure_NSuch processes, described herein or according to other floor request processes, are well known to those skilled in the art. In response to a dispatcher or agent floor request, the processing of the request may be in accordance with the CD shown in FIG. 5_NThe access request process 500 continues. Alternatively, the scheduler may be directed to a CD or CD that is not affected by any floor restriction or floor prioritization criteria and thus more quickly results in the floor being granted_NThe agent issues an access request.

Determination 604 identifies the floor grant generated and, thus, the dispatcher or other group member monitors (606) for traffic from the CD_NTo communicate. The resulting monitoring may allow disabling of the user from making an emergency service voice request or may allow monitoring of situational or conditional data.

FIG. 7 illustrates a flow chart of yet another embodiment of the present inventionFigure (a). In granting the floor to a specified CD_NWhen in contact with the CD_NThe floor is reserved until the user releases the floor. In an emergency or disaster event, a CD_NThe floor may be owned and may not be able to be relinquished or released to other users due to an emergency or catastrophic condition, or the scheduler may determine that the communication resources are immediately needed by another user. Thus, the present embodiment of the invention enables the scheduler to release (610) the assigned CD_NThe floor held thereby allowing other members of the group to utilize the communication resource.

Those of skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with the following means: a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (45)

1. A method for communicating between a communication group of a plurality of wireless communication devices in a communication system, comprising:

forming the communication group, including:

transmitting an invitation to join the communication group to the plurality of wireless communication devices, the invitation including group membership location criteria;

evaluating the group membership location criteria at each of the plurality of wireless communication devices receiving the invitation;

forming the communication group consisting of wireless communication devices of the plurality of wireless communication devices that satisfy the group membership location criteria; and

granting permission to transmit to others of the plurality of wireless communication devices of the communication group to one of the plurality of wireless communication devices of the communication group.

2. The method of claim 1, wherein the forming the communication group further comprises: accepting, by each of the plurality of wireless communication devices that satisfies the group membership location criteria, the invitation to join the communication group.

3. The method of claim 1, further comprising: broadcasting a flag in a first common channel that directs the plurality of wireless communication devices to monitor a second common channel that includes the invitation.

4. The method of claim 2, wherein the first common channel is a paging channel.

5. The method of claim 2, wherein the second common channel is an emergency common channel.

6. The method of claim 1, wherein evaluating the group member location criteria comprises: comparing a current location of each of the plurality of wireless communication devices receiving the invitation to the group membership location criteria to determine wireless communication devices of the plurality of wireless communication devices that are within the group membership location criteria.

7. The method of claim 1, wherein the granting transmission permission to one of the plurality of wireless communication devices of the communication group further comprises: an availability of communication resources to be granted in the communication system is determined, and access to the communication resources is granted to the one of the plurality of wireless communication devices of the communication group when the communication resources are available.

8. The method of claim 1, wherein the granting transmission permission to one of the plurality of wireless communication devices of the communication group further comprises: denying access to the communication resource to the one of the plurality of wireless communication devices when the floor-authorization criteria restricts the one of the plurality of wireless communication devices from accessing the communication resource.

9. The method of claim 1, wherein the granting transmission permission to one of the plurality of wireless communication devices of the communication group further comprises: when the prioritization criteria prioritize access to the communication resource by one of the plurality of wireless communication devices, the granting of access to the communication resource by the one of the plurality of wireless communication devices is prioritized.

10. The method of claim 1, wherein the granting transmission permission to one of the plurality of wireless communication devices of the communication group further comprises: requesting, by another, permission for the one of the plurality of wireless communication devices to transmit to the other of the plurality of wireless communication devices.

11. The method of claim 1, further comprising: releasing, by another one of the plurality of wireless communication devices, permission for the one of the plurality of wireless communication devices to transmit to the other one of the plurality of wireless communication devices of the communication group.

12. In a wireless communication device, a method of communicating among a communication group of a plurality of wireless communication devices in a communication system, comprising:

joining the communication group, comprising:

receiving an invitation to the plurality of wireless communication devices to join the communication group, the invitation including group membership location criteria;

evaluating the group membership location criteria at each of the plurality of wireless communication devices receiving the invitation; and

joining the communication group; and

transmitting to other ones of the plurality of wireless communication devices of the communication group upon receiving permission to transmit to other ones of the plurality of wireless communication devices of the communication group in the communication system.

13. The method of claim 12, wherein the forming the communication group further comprises: accepting the invitation to join the communication group when the wireless communication device satisfies the group membership location criteria.

14. The method of claim 12, further comprising: monitoring a first common channel for a flag directing the wireless communication device to monitor a second common channel including the invitation.

15. The method of claim 13, wherein the first common channel is a paging channel.

16. The method of claim 13, wherein the second common channel is an emergency common channel.

17. The method of claim 12, wherein evaluating the group member location criteria comprises comparing a current location of the wireless communication device to the group member location criteria to determine whether the wireless communication device is within the group member location criteria.

18. A wireless communication system, comprising:

a communication manager including a dispatcher interface configured to generate an invitation to join a communication group, the invitation including group membership location criteria, the communication manager further configured to grant permission to one of the groups to transmit to others of the communication group.

A base station configured to transmit the invitation to join the communication group; and

a plurality of wireless communication devices configured to evaluate the group membership location criteria at each of the plurality of wireless communication devices receiving the invitation, a wireless communication device of the plurality of wireless communication devices that satisfies the group membership location criteria further configured to accept the invitation to join the communication group, one of the plurality of wireless communication devices further configured to receive the transmission permission and transmit to the other of the communication group in response thereto.

19. The wireless communication system of claim 18, wherein the communication manager and the base station are further configured to broadcast a flag in a first common channel directing the plurality of wireless communication devices to monitor a second common channel that includes the invitation.

20. The wireless communication system of claim 19, wherein the first common channel is a paging channel.

21. The wireless communication system of claim 19, wherein the second common channel is an emergency common channel.

22. The wireless communication system of claim 18, wherein each of the plurality of wireless communication devices is further configured to compare a current location of the each of the plurality of wireless communication devices to the group membership location criteria to determine whether the each of the plurality of wireless communication devices is within the group membership location criteria.

23. The wireless communication system of claim 18, wherein the communication manager is further configured to determine availability of communication resources to be granted in the communication system, and grant access to the communication resources to the one of the plurality of wireless communication devices of the communication group when the communication resources are available.

24. The wireless communication system of claim 18, wherein the communication manager is further configured to deny granting access to communication resources to the one of the plurality of wireless communication devices when a floor-authority criterion restricts access to the one of the plurality of wireless communication devices.

25. The wireless communication system of claim 18, wherein the communication manager is further configured to prioritize granting of communication resource access by the one of the plurality of wireless communication devices when a prioritization criterion prioritizes access to communication resources by the one of the plurality of wireless communication devices.

26. The wireless communication system of claim 18, wherein the communication manager is further configured to grant transmission permission to one of the plurality of wireless communication devices of the communication group when permission for the one of the plurality of wireless communication devices to transmit to the other of the plurality of wireless communication devices is requested by another one.

27. The wireless communication system of claim 18, wherein the communication manager is further configured to release permission by another one of the plurality of wireless communication devices to transmit to other ones of the plurality of wireless communication devices of the communication group.

28. A communication device for communicating among a communication group of a plurality of wireless communication devices, comprising:

a joining device for joining the communication group, comprising:

receiving means for receiving an invitation to the plurality of wireless communication devices to join the communication group, the invitation including group membership location criteria;

evaluating means for evaluating the group membership location criteria at each of the plurality of wireless communication devices receiving the invitation; and

joining means for joining the communication group; and

transmitting means for transmitting to other ones of the plurality of wireless communication devices of the communication group upon receiving permission to transmit to other ones of the plurality of wireless communication devices of the communication group in a communication system.

29. The communication device of claim 28, wherein means for forming the communication group further comprises means for accepting the invitation to join the communication group when the wireless communication device satisfies the group membership location criteria.

30. The communications device of claim 28, further comprising means for monitoring a first common channel for a flag that directs the wireless communications device to monitor a second common channel that includes the invitation.

31. The communications apparatus of claim 29, wherein the first common channel is a paging channel.

32. The communication device of claim 29, wherein the second common channel is an emergency common channel.

33. The communications device of claim 28, wherein means for evaluating the group member location criteria comprises means for comparing a current location of the wireless communications device with the group member location criteria to determine whether the wireless communications device is within the group member location criteria.

34. A computer readable medium embodying a method of communicating between a communication group of a plurality of wireless communication devices in a communication system, the method comprising:

forming the communication group, including:

transmitting an invitation to join the communication group to the plurality of wireless communication devices, the invitation including group membership location criteria;

evaluating the group membership location criteria at each of the plurality of wireless communication devices receiving the invitation; and

forming the communication group consisting of wireless communication devices of the plurality of wireless communication devices that satisfy the group membership location criteria; and

granting permission to transmit to others of the plurality of wireless communication devices of the communication group to one of the plurality of wireless communication devices of the communication group.

35. A computer readable medium including the method of claim 34, wherein in the method, wherein the forming the communication group further comprises: accepting, by each of the plurality of wireless communication devices that satisfies the group membership location criteria, the invitation to join the communication group.

36. A computer readable medium embodying the method of claim 34, wherein the method further comprises: broadcasting a flag in a first common channel that directs the plurality of wireless communication devices to monitor a second common channel that includes the invitation.

37. A computer readable medium including the method of claim 34, wherein in the method, wherein the evaluating the group membership location criteria comprises: comparing a current location of each of the plurality of wireless communication devices receiving the invitation to the group membership location criteria to determine wireless communication devices of the plurality of wireless communication devices that are within the group membership location criteria.

38. The computer readable medium including the method of claim 34, wherein in the method, wherein the granting transmission permission to one of the plurality of wireless communication devices of the communication group further comprises: denying access to the communication resource to the one of the plurality of wireless communication devices when the floor-authorization criteria restricts the one of the plurality of wireless communication devices from accessing the communication resource.

39. The computer readable medium including the method of claim 34, wherein in the method, wherein the granting transmission permission to one of the plurality of wireless communication devices of the communication group further comprises: when the prioritization criteria prioritizes access to the communication resource by the one of the plurality of wireless communication devices, prioritizing granting of access to the communication resource by the one of the plurality of wireless communication devices.

40. The computer readable medium including the method of claim 34, wherein in the method, wherein the granting transmission permission to one of the plurality of wireless communication devices of the communication group further comprises: requesting, by another, permission for the one of the plurality of wireless communication devices to transmit to the other of the plurality of wireless communication devices.

41. A computer readable medium embodying the method of claim 34, wherein the method further comprises: releasing, by another one of the plurality of wireless communication devices, permission for the one of the plurality of wireless communication devices to transmit to the other one of the plurality of wireless communication devices of the communication group.

42. A computer-readable medium embodying a method of communicating in a communication group of a plurality of wireless communication devices in a communication system, the method comprising:

joining the communication group, comprising:

receiving an invitation to the plurality of wireless communication devices to join the communication group, the invitation including group membership location criteria;

evaluating the group membership location criteria at each of the plurality of wireless communication devices receiving the invitation; and

joining the communication group; and

transmitting to other ones of the plurality of wireless communication devices of the communication group upon receiving permission to transmit to other ones of the plurality of wireless communication devices of the communication group in the communication system.

43. A computer readable medium including the method of claim 42, wherein in the method, wherein forming the communication group further comprises: accepting the invitation to join the communication group when the wireless communication device satisfies the group membership location criteria.

44. A computer readable medium embodying the method of claim 42, the method further comprising: monitoring a first common channel for a flag directing the wireless communication device to monitor a second common channel including the invitation.

45. A computer readable medium including the method of claim 42, wherein in the method, wherein the evaluating the group membership location criteria comprises: comparing a current location of the wireless communication device to the group member location criteria to determine whether the wireless communication device is within the group member location criteria.