BR112017013178B1 - INTERNET PROTOCOL BASED STATION THAT PROVIDES AT LEAST ONE OF ONE ADVERTISING PAGE AND PARTY LINE CONFERENCE RELATIVE TO OTHER IP BASED STATIONS - Google Patents

Abstract

INTERNET PROTOCOL (IP) SERVERLESS PAGE PARTY (SPP) STATION AND SYSTEMS AND METHODS FOR MULTIPLE STATION DEPLOYMENT. The present invention relates to a serverless Page Party (SPP) station for page announcement and line party conferencing that is configured to implement mutual provisioning so as to allow all SPP stations within a system to mutually maintain their configurations in runtime, and multiple master station negotiation and master failover. Multiple SPP stations are connected with an Ethernet or WIFi cable to a network and thus without the need for expensive cabling and cumbersome daisy-chaining setup between stations. SPP stations forward packets to each other using multicast technology and without the need for an IP-PBX or other server (for example, a SIP server) to control connections between stations. In Mutual Provisioning Mode, SPP stations operate using a system configuration obtained from other SPP stations already in the network using a command channel. The system configuration is maintained by an SPP station designated as a master station. Several SPP stations can negotiate with each other to designate a new station (...).

Description

BACKGROUND OF THE INVENTION FIELD OF THE INVENTION:

[001] The present invention relates to an IP-based serverless Page Party (SPP) station and methods and apparatus for deploying multiple SPP stations using multicast technology.

DESCRIPTION OF RELATED TECHNIQUE:

[002] An existing "Analog" Page Party station is a product that is widely used in deployments where both Page Announcement and Line Party Conferences are a necessity. Multiple stations operate together to allow multiple users to talk on up to 5 channels , in addition to allowing Page Ads to be made simultaneously on local speakers.

[003] Such systems are modular, thus obtaining the advantage of being a decentralized system that does not have a single point of failure. Cabling in Page/Party systems, such as the system depicted in Figure 1, however, can be expensive and cumbersome.

[004] For example, the more Page or Party lines required for an installation and the greater the distance between the devices, the greater the cabling cost. When traditional phones can contact multiple endpoints (with the help of an exchange) on a single physical line, Page Party requires a single line per channel. The result is that a large bundle of wires connected to each station is used. Additionally, station enclosures must be large enough to accommodate additional cables for future service loops.

[005] Another approach uses a base network as the communications infrastructure and Voice over IP (VoIP) devices. With networks, multiple "channels" can be used on a single cable. It may be possible to deploy multiple IP devices on an existing base network, further reducing the cost of added infrastructure. Such traditional VoIP solutions, however, require the use of a VoIP switch in the same way that an analog telephone system might require a switch. This approach fails to realize the power of decentralization, introducing a single point of failure that would otherwise not be present in a Page Partyanalog system.

[006] Therefore, there is a need for an improved Page Party station that does not require expensive and cumbersome cabling and an improved system for deploying multiple Page Party stations that do not require interconnection control using a server or other centralized point of failure or single.

SUMMARY OF THE INVENTION

[007] The problems discussed above and others are overcome and additional advantages are obtained, by illustrative embodiments of the present invention.

[008] According to aspects of illustrative embodiments of the present invention, a Page Party station provides Page announcement and Party line conference in relation to other Page Party stations. The Page Party station is connected to other Page Party stations in a network that supports multicast and peer-to-peer communication. The Page Party station comprises: a network interface for connecting the Page Party station to the network; a plurality of configurable multicast addresses for transmitting and receiving audio in line Party conferencing with other Page Party stations; a plurality of configurable multicast addresses to transmit Page advertisements to other Page Party stations; a Party line selector to select one of the multicast addresses for Party line conferencing; a Page row selector to select one of the multicast addresses for Page advertising; and a processing device that operates in a mutual provisioning mode to configure the station to provide Page announcement and Party line conferencing operations using Voice over Internet Protocol (VoIP) on the network. Mutual provisioning mode allocates multicast addresses to designate Page sockets and Party line sockets used by the Page Party station and other Page Party stations on the network according to a system configuration. The Page Party station, once configured, operates to listen to its configured Page sockets for incoming audio, to transmit audio on its configured Page sockets, and to participate in Party line conferencing on its partially configured line sockets according to the system configuration. .

[009] According to aspects of illustrative embodiments of the present invention, the processing device is configured to operate the Page Party station as a master station in relation to other Page Party stations and maintain the system configuration.

[010] According to aspects of illustrative embodiments of the present invention, the system configuration comprises assigning a selected multicast address to a command channel used by the Page Party station and other Page Party stations, and the Page Party station that operates as a master station can listen on the command channel for an announcement provided on the command channel by another Page Party station and send responses to that Page Party station via the command channel.

[011] According to aspects of illustrative embodiments of the present invention, the system configuration comprises a list of master stations, and the processing device is programmed to negotiate with other Page Party stations in the master list to designate one of them as the new station teacher.

[012] According to aspects of illustrative embodiments of the present invention, the network interface is at least one of an Ethernet cable interface and a WiFi interface.

[013] According to aspects of illustrative embodiments of the present invention, the Page Party station additionally comprises a local power supply.

[014] According to aspects of illustrative embodiments of the present invention, the Page Party station is configured for at least one of IPv4-enabled communication and IPv6-enabled communication with other Page Party stations.

[015] According to aspects of illustrative embodiments of the present invention, audio transmitted and received through the Page Party station comprises a real-time transport protocol (RTP) layer of structured packets in accordance with the RFC 3550 internet standard.

[016] According to aspects of illustrative embodiments of the present invention, the system configuration comprises at least two virtual zones defined using designated station identifiers and zone identifiers.

[017] Additional and/or other aspects and advantages of the present invention will be presented in the following description, or will be obvious from the description, or can be learned through the practice of the invention. The present invention may comprise a Page Party station or Page Party system and methods for configuring and/or operating the same having one or more of the above aspects, and/or one or more features and combinations thereof. The present invention may comprise one or more features and/or combinations of the aspects cited, for example, in the attached claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[018] The present invention will be more readily understood with reference to the illustrative embodiments as shown in the attached figures, in which:

[019] Figure 1 is a block diagram illustrating a conventional analog Page Party system.

[020] Figure 2A is a front view of a conventional Page Party station.

[021] Figure 2B is a top view of a conventional Page Party station.

[022] Figure 3A is a front view of a serverless Page Party station according to an illustrative embodiment in the present invention.

[023] Figure 3B is a top view of the serverless Page Party station.

[024] Figure 3C is a rear view of a rear view of the front panel of the serverless Page Party station.

[025] Figure 3D is an internal view of the serverless Page Party station (SPP).

[026] Figures 4, 5, 6, 7 and 8 are illustrations of multiple SPP stations in an illustrative installation.

[027] Figure 9 is a block diagram of a control board printed on the SPP station.

[028] Figure 10 is a block diagram representing hardware inputs and outputs in relation to a processor on the control board printed in Figure 9.

[029] Figure 11 is a block diagram representing software modules in relation to a processor on the control board printed in Figure 9.

[030] Figures 12, 13, 14, 15, 16, 17 and 18 are state diagrams implemented by the various software modules in Figure 11.

[031] Figures 19, 20 and 21 illustrate a command channel flow between the SPP station in accordance with illustrative embodiments of the present invention.

[032] Figure 22 illustrates an illustrative data packet transmitted and received by SPP stations in accordance with an illustrative embodiment of the present invention.

[033] Throughout the figures, similar numerical references will be understood to refer to similar elements, characteristics and structures.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[034] Reference will now be made in detail to embodiments of the present invention, which are illustrated in the attached drawings. The embodiments described herein exemplify, but do not limit, the present invention when referring to the drawings.

[035] In accordance with advantageous aspects of illustrative embodiments of the present invention and with reference to Figures 3A, 3B, 3C and 3D, an enhanced Page Party station 20 is provided (for example, later in this document referred to as a Page Party station without server (SPP)) that employs multicast, that is, technology to enable multiple IP devices configured to listen on a given broadcast address in order to receive data over a network from a single source. The SPP station is configured to have one or more of the following features:

[036]* Enabled for IPv4 / IPv6.

[037]« Telephone with Press Bar to control Page/Party mode.

[038]* Five Configurable Multicast Channels for conference talk with Party Line Selector.

[039]* Eight Configurable Multicast Channels for Page ads with Page Line Selector.

[040]* Six Configurable Outputs.

[041]* Onboard amplifier with non-audible self-check feature and Ambient Level detection.

[042]* Auxiliary analog audio input.

[043]* Operation with between 2 and 4095 stations per system.

[044]* Mutual Provisioning Mode for easy solution deployment.

[045] As mentioned above, the conventional stations 15 in the system depicted in Figure 1 are connected to a heavy cable 17 (e.g., a core cable 16) comprising Page, Party lines and electrical power transmission lines in a scheme of daisy-chain wiring extending from a main cabinet to a zone comprising a group of 15 stations within a designated area. The SPP station avoids the need for a bulky cable such as cable 17 and the impractical sequential station configuration 15 as it is configured with local power and a much less complicated Ethernet cable connection with the existing network infrastructure having an installation Standard Ethernet and information technology (IT) and other SPP stations. Additionally, SPP stations can be configured to be in virtual zones and are not limited to being in designated physical area zones due to the proximity required for the conventional station daisy chain wiring scheme 15.

[046] For existing Page/Party systems that employ VoIP, each station 15 or VoIP phone must be commissioned through a central SIP server or IP-PBX which represents a single undesirable point of failure. The SPP station 20 is advantageous over existing stations 15, as it is configured to be serverless in terms of connections to other SPP stations 20, and can only use an optional server for configuration and updates, for example. As described below, each SPP station 20 is also configured to be self-aware, allowing simple replacement of stations 20 without recommissioning via a SIP or IP-PBX server.

[047] Additionally, the SPP station 20 is essentially real-time operational in that multicast is instantly available on the Party line without the need for a conference bridge and additional time required to set up a conference on older systems (or that is, the delay associated with a SIP/server or conference bridge that selects a line for a user, the user dials into the conference, and then presses a Page button, the paging port of an IP-PBX to an amplifier that is being dialed, the Page button is released and the call is then forwarded to the conference bridge).

[048] According to advantageous aspects of the present invention, a customer IT personnel or other administrator can easily allocate or program addresses/ports or multicast sockets for the respective Party and Page lines employed by the SPP stations 20. The SPP stations can , then listen to RTP on sockets for which they are configured to listen as part of a designated group and convert the RTP to audio for playback. Each SPP station in a group can be listening to a Party line, and several people can broadcast on the same Party line, without the need for an IP-PBX or similar device.

[049] As described herein, SPP stations 20 and other advantageous aspects of illustrative embodiments of the present invention allow the elimination of a DHCP server. One or more SPP stations 20 can be designated as master stations to manage the configuration and update of any SPP station in your system.

SPP 20 Station Operations Overview

[050] Page/Party operations are emulated using VoIP.

[051]Party Line Operation:

[052]1. The Party line selector switch has an address/port or multicast socket assigned to each of the five Party lines for both transmitting and listening when selected.

[053]2. Station 20 will listen to Page sockets as described in Page Operation below.

[054]3. When a Party line is selected and the handset is off-hook, if configured, audio from the amplifier will be muted and audio from the selected multicast socket will be routed to the headset and audio from the handset microphone will be transmitted to the multicast socket.

[055] Page Operation:

[056] Station 20 may broadcast received Page audio while the unit is off-hook in a Party line conversation.

[057]1. A multicast socket is used to transmit and listen to the Page line. Page audio is not typically monitored in the headset, but station 20 can be configured so that a station listens to Page audio in the headset when the push bar is pressed.

[058]2. The SPP 20 station performs idle listening for all configured Page sockets by routing the received Page audio appropriately to the amplifier. Audio is not routed to the Page line until the telephone set is lifted and the Press Bar is pressed. When the Push Bar is pressed, audio from the designated Page line socket is routed to the headphone jack and audio from the microphone is routed to the Page line socket.

[059]3. Zoning can be performed in a manner similar to current multicast groups on the VoIP telephone described in US Commonly Owned Patent Application No. 14/471,642 using the same priority scheme. Station 20 preferably only receives Pages on the configured Page Receive sockets. A multicast socket can be designated as the local zone socket. This local zone socket can be used for paging from the station. All stations in the same local zone will be disabled using the local Page zone socket. The station also listens to the other X Page sockets.

[060]4. Mutual Mute is achieved by using the contributing source identifier (CSRC) in the RTP audio packet header. Station 20 may allow up to a designated number of CSRC's to be configured in addition to its own. Upon receipt of RTP from any of the configured CSRC's, the station discards the packet. If audio is received from a CSRC that is not configured, it is routed to the Page amplifier assuming it has priority. Audio is preferably only routed to the handset if the same local zone socket as the station and the telephone set is off-hook and the Push Bar is pressed.

[061]5. A pre-announcement tone is configurable and transmitted to both the headset and Page line before routing voice audio from the handset microphone.

[062]6. If a higher priority Page is broadcasting in the local zone, station 20 does not allow a Page to begin, and a busy tone may be heard in the headset while the telephone set is off-hook and the Push Bar is pressed . The Busy Tone can be configurable with the Snooze function described in function item 9 below.

[063]7. Station 20 may support a 600 Ohm audio output to route received audio to an external amplifier or other device with a feedback contact closure that indicates the presence of audio at the output.

[064]8. Station 20 may have a 600 Ohm audio input to transmit external audio in the designated Page zone. Additionally, there may be a contact closure input to indicate when external audio should be broadcast. External audio preferably has the same priority scheme as voice audio in that it is prohibited if a higher priority Page is being broadcast in the local Page zone.

[065]9. In addition to the 5 Party Line sockets, station 20 can listen to up to, for example, 8 other Page sockets configurable for incoming Page audio. Each Page socket has a priority associated with it from 1 to 8. When idle or in a Party Line Conference, station 20 will route the highest priority Page Audio stream being received at the station to the amplifier. . Station 20 can be configured to make Page announcements on up to four of the 8 existing Page sockets. When making a Page announcement, the socket used will be the one selected by the Page Zone Selector switch. If this zone is the same as the one being received, then the user will participate in the announcement. In this case, the audio is currently routed to the amplifier instead of the headphones. Each Page socket can be configured to defer. If the selected Line Page is set to snooze, then station 20 will not allow the user to participate in the current advertisement. Instead, a busy tone will be played in the headset if the incoming audio is on a different priority socket than the selected Page zone when the Press Bar is pressed, so the user can make a Page announcement normally without affecting the audio Page on the amplifier.

[066] SNMP can be used as a method for station monitoring. Health checks may include:

[067]a. Device is online and functional

[068]b. Telephone device is in use/off the hook

[069]c. Device currently paging

[070]d. Telephone device integrity

[071]e. Telephone Amplifier Integrity

[072]f. Speaker Amplifier Integrity

[073]g. Speaker integrity

[074] Power can be supplied via power over Ethernet (PoE) to provide maximum output power under POE, or via universal AC AUX or 24VDC AUX.

Illustrative Usage Scenarios

[075] Figure 4 shows an exemplary installation scenario for multiple SPP stations 20 referred to as stations A to H. All stations 20 are connected to a network 40, each via a single cable 36 (e.g., in this case, an Ethernet cable such as a Cat 5 cable). Network 40 could be a simple single network switch or a complex network. The behavior of the network itself is beyond the scope of this invention and is omitted herein for brevity. The network is generally existing infrastructure available at the deployment location and simply needs to be configured in a way that allows all SPP stations 20 to forward network packets to one another, this includes the need for all nodes within the network 40 to handle the multicast-based traffic as well as point-to-point traffic.

[076] The ability to (1) connect the SPP 20 stations merely with an Ethernet cable to a network, and (2) the stations to forward packets between each other through multicast technology and, therefore, without the need for an IP- PBX or other server (e.g., a server) to control interstation connections 20, realize significant advantages over existing analog Page/Party systems, and existing Intelligent Page/Party systems that employ IP-PBXs or other switching or switching. As mentioned above, the stations 15 in the system depicted in Figure 1 are connected to a heavy cable 17 (e.g., a 16-core cable), for example, in a daisy-chain wiring scheme. Consequently, the more stations 15 are used, the more cabling is required, which can be expensive. Furthermore, each station 15 is provided with an additional length of cable 17 for future service loop connections. In many cases, a station 15 compartment has 60.96 cm (2 feet) of bulky cable stored therein, this requires a proportionately large compartment for the station 15. The SPP station 20 compartment 23 can be almost % of the width of the station 15 as illustrated when comparing Figures 3A and 3B with Figures 2A and 2B respectively. SPP SPP 20 stations are less expensive to manufacture and are easier to install at more customer locations than conventional 15 stations due to the smaller overall station 20 profiles.

[077] Unlike a Smart Page/Party system that uses an IP-PBX or SIP server for IP paging or conference connections, the SPP 20 stations are configured to be serverless, as described below, thus avoiding a single Potential and unwanted point of failure associated with systems that use centralized paging control between stations.

[078] Figure 5 shows Users on Station A, Station C and Station E in a Party Line Conference on Party Line 1. All 3 users are using their SPP station handsets with the Press Bar released and the Power Selector Switch Party Line set to 1. All 3 Users can chat freely with each other.

[079] Figure 6 shows Users on Station B and Station D in a Party Line Conference on Party Line 2. Both users are using their SPP station handsets with the Press Bar released and the Party Line Selector Switch set to 2. These 2 Users can chat freely with each other. The Users in the scenario in Figure 5 are using the system simultaneously with the Users at Stations B and D. Each group of Users is participating in their own separate conversation through the system.

[080] Figure 7 shows a User at Station G using their telephone handset with the Press Bar held down and the Page Destination Zone Selector Switch set to 1 to make a Page Announcement to other stations listening in Zone Page 1 In this case, Station C, Station D and Station H are internally configured to listen in Zone Page 1 and thus these stations will reproduce speech from the speakers/amplifiers connected to it and not to the telephone device. This audio is one-way, so no audio is heard at Station G. Users in the scenarios in Figure 5 and Figure 6 are using the system simultaneously with the User at Station G. Page audio can be transmitted from the speaker/amplifier on Station C while the User on Station C can chat in a separate conversation via Party Line 1.

[081] Figure 8 shows Users at Station G and Station H using their devices with the Push Bar held down and the Page Destination Zone Selector Switch set to 2 to make a Page Announcement to other stations listening in the Zone Page 2. In this case, Station E and Station D are configured to listen in Zone Page 2 and so these stations will play speech from the speakers/amplifiers connected to it. Station D is configured to listen in both Zone Page 1 and Zone Page 2. Since Zone Page 2 is set to a higher priority than Zone Page 1, Station D now ignores audio from Zone Page 1 and instead of transmitting the audio from Zone Page 2.

Serverless Page/Party Station Configuration (SPP) 20

[082] Still referring to Figures 3A to 3D and with reference to Figures 9 and 10, an SPP station 20 has a compartment 23 with a front panel 21. A telephone handset 22 and support base 30 are provided. A user has access to a Line selector switch 24 and a Party Line selector switch 26 of the front panel 21. The underside of the telephone apparatus 22 may be provided with a Press Bar 28 in a conventional manner. It will be understood that the Line Selector Switch Page 24, Line Party Selector Switch 26 and Press Bar 28 may have different form factors and may be provided in the SPP Station 20 in locations other than those depicted in Figure 3A. A main printed circuit board (PCB) 32 is connected to the bottom side of the front board 21 as shown in Figure 3C, but may be mounted within the housing 23 in a different orientation or location. The housing comprises a power source CD 34 as shown in Figure 3D, although other means for providing DC or AC power may be employed. The station is connected to an Ethernet cable in the conventional way (not shown). The station may also be configured for WiFi communication in a manner as described in US Commonly Owned Patent Application No. 14/471,642, filed August 28, 2014.

[083] Some of the components on the main PCB 32 are shown in Figure 9. The main PCB 32 comprises a processor 50, a flash memory 52, a SRAM 54, an Ethernet connection 56 (for example, a Cat5 or other Ethernet interface) and related physical interface circuit (PHY) 58, and a power over Ethernet (PoE) interface) 60. A non-volatile memory can be used to store, for example, Application data for maintaining a static firmware image and Configuration data for store modifiable data such as configuration settings, internal events, and so on. Various TDM codecs generally indicated in reference number 62 are provided for processing signals received and transmitted over the Ethernet connection. An optional primary codec 64 and an optional secondary codec 66 are provided for processing audio signals from the speaker 68 and microphone 70 and the other audio interface (e.g., a telephone handset) 72 at the SPP station 20. The main PCB 32 also provides an I/O decoding circuit 74 for connecting different inputs to the processor and conditioning different output signals from the processor. An amplifier circuit 80 (Figure 10) may be provided on the main PCB 32 or be provided on a separate board within the enclosure. An optional Watchdog (WDOG) circuit 76 and UART connection 78 can also be provided.

[084] Referring to Figure 10, is a block diagram representing different SPP station hardware elements 20 and their respective inputs and/or outputs in relation to processor 50. Party Line Selector Switch 26 is used to select which one of the various Party lines (e.g. lines 1 through 5, although a different number of Party lines may be used) is currently in use by the SPP station. The Hook Switch detects whether the Telephone Device is on-hook or not. The Page 24 Line Selector Switch is used to select the current Page Zone in use by the SPP station. A designated number of Page Lines (e.g. 1 to 4) can be used. The Press bar (e.g. on the bottom side of the telephone set 22) is used to select audio Page. The handset (e.g., on telephone handset 22) is used to play audio received by the SPP station. The microphone (e.g., in telephone handset 22) is used for actual sound sampling of the user's voice. The Amplifier 80 shown as the Amplifier Output in Figure 10 is used to reproduce Page audio through an Amplifier and speaker 68 powered or connected to the SPP station 20. An Amplifier Input (e.g., the Amplifier load) is provided, along with an Amplifier Load Sensor used to read a voltage returned from an Amplifier Health Checker. Amplifier State Control is used to control Amplifier Mode. The outputs are used to drive external peripherals such as Relays or LEDs. For example, a Heartbeat LED is used for visual indication. The Ethernet MAC (EMAC) is used for network communication with other devices, including the transmission and reception of audio data as well as secondary network services. An Auxiliary Audio Input is used to sample audio from an external analog source. For example, an Auxiliary Audio Contact can be used to indicate to the SPP station that it should sample audio from the Auxiliary Audio Input rather than the microphone for an Announcement Page. A UART can be used to output string data from the SPP 20 station.

[085] With reference to Figures 11 to 18, the operations of SPP station 20 components and software for controlling them will now be described.

[086] Figure 11 is a block diagram representing software elements or modules in processor 50 of SPP station 20. Physical devices 88 are described above with reference to Figures 9 and 10. Device drivers 90 are a collection of processes that form a control and data interface to the actual hardware devices. They implement hardware control on behalf of application processes and can be hardware dependent. For example, an Ethernet MAC driver initializes the Ethernet MAC and implements the functions necessary for data to be written to and read from the device. A codec driver implements a stream of input and output local audio data at station 20. The codec driver initializes any hardware relating to the Microphone, Phone, Auxiliary Audio Input and Amplifier, provides PCM data from the Microphone and Auxiliary Audio Input to the application layer for reading and receives PCM data from the application later for writing to the Phone and Amplifier. A Timer driver can be provided to implement timing signals needed by the rest of the system. For example, the Timer driver can handle timer interrupts generated by a hardware timer.

[087] Still referring to Figure 11, a bootstrap process 100 provides an initial process that is executed when power is applied to the SPP station 20. This process, for example, comprises the following operations:

[088]* Performs a CRC Check on non-volatile memory contents.

[089]* Initialize Device Drivers 90

[090]* Initializes Programmer 102

[091]* Initializes Internal Command System 92

[092]* Initializes Station Clock 118

[093]* Initializes Configuration Manager 104

[094]* Initializes Audio Manager 106

[095]* Initializes the General I/O Manager 108

[096]* Initialize Telnet 112 Client

[097]* Initializes SNMP Client 114

[098]* Initialize TFTP Client 116

[099]* Initializes Health Monitor 110

[0100] When all these processes are completed, the bootstrap process 100 transfers control to the Programmer 102. The Programmer 102 manages the resource usage of the other software processes in the system, for example, ensuring that urgent processes (e.g. (e.g., audio-related tasks) that require certain resources can obtain those resources when needed (e.g., postponing all non-urgent processes until resources are available to handle them). The primary requirement for Programmer 102 in this system is to ensure that audio transmission and reception time requirements can be met.

SETTINGS MANAGER

[0101] Still referring to Figure 11, the SPP station 20 supports a Configuration Manager 104. The Configuration Manager is responsible for maintaining the current configuration of the running station. Configuration Manager handles all requirements for reading and writing configuration data in non-volatile memory and for the current running configuration. The Configuration Manager 104 is responsible for validating each of the fields it maintains. For example, the configurable fields may be as indicated in the Appendix below. Figure 17 is an illustrative state diagram for a Configuration Manager as it handles configuration change requests, stores/retrieves configuration data, maintains the running configuration state, and makes the configuration state available to other services in the Configuration Manager. system.

[0102]Command Channel. Configuration Manager 104 may use a dedicated Multicast Address/Port to communicate with other SPP stations, called a "Command Channel." All SPP stations that have visibility and access to this channel can send and receive text data on this channel. Illustrative commands are provided in the table below: MUTUAL PROVISIONING MODE PROTOCOL COMMANDS

[0103]Configuration Storage. Each SPP 20 station individually maintains a copy of the running System Configuration at run time and also in non-volatile storage so that it persists between shutdowns.

[0104]System Configuration. SPP 20 stations use a formal configuration structure called “System Configuration”. This structure contains the configuration of all SPP stations within the system. System Configuration is always preferably used independently of the various Configuration options available. A System Configuration consists of the following logical elements:

[0105]System Designation. The System Designation is a string value (e.g. “GTUK Burton”) that indicates which system the SPP station belongs to. It is mainly used to avoid conflicts and corrupted data when stations are moved between systems. The Administrator must set this value as a unique string to discriminate your System from any other that may be on your network or used in your organization.

[0106]There is a reserved designation value “FACTORY”. This designation indicates that the SPP station has the default System Configuration applied. This value cannot be adjusted in SPP manually - it is applied at the time of manufacture or when restored to factory defaults.

[0107]System Version. The System Version is an integer that defines the version of the System Configuration on a given workstation. This version number must be incremented by the Administrator when changes are made to the System Configuration, so that the new System Configuration is proliferated to all other stations within that System.

[0108]Group Number. A group must describe common or general settings that apply to a large number of SPP stations. A System Configuration can define up to 16 Group Numbers. Each Group Number is a unique number within the System Configuration between 0 and 15. This number is unique and has up to 255 Station Numbers associated with it. The Group Number corresponds directly to and is selected by the value defined by the Group Selector Switch (Figure 10).

[0109] Each Group has a single Group Configuration associated with it. This is a list of configurable fields within the SPP station that are used for all stations within that Group. For details on which fields are adjusted by the Group, see the Appendix below. Each Group also specifies the Network Mode for that Group and any fields required for that mode of operation.

[0110] Each Group also specifies a standard usage Profile for all stations within that Group.

[0111] Station Number A Station Number is used to identify a specific station within a Group. Each Station Number within a Group must be unique. The Station Number corresponds directly to the value configured by the Station Number Selector Switch.

[0112]Station Name. A Station Name is an identifier that consists of two parts; The Group number and Station Number. For example, Station Name “2.54” could represent “Station Number 54 in Group 2”. Each Station Name has a unique Profile associated with it.

[0113]Master List. The Master List is a comma-delimited list of Station Names. It describes which stations in this system should act as “Master” stations. It also describes the Order of Preference. The Order of Preference is used to determine which of the Masters should assume the role of Master Station in the event that the highest in the Order of Preference is absent from the network. For example, “0.1, 1.3, 0.2” could indicate that the Master Station is 0.1, which fails about 1.3, which fails about 0.2.

[0114]Profile. A Profile is a list of configuration settings that apply to local and/or station-specific adjustments. Up to 64 profiles can be defined within a System Configuration. A single Profile can be applied to as many stations as needed. Note that some configuration data can be defined in both a Profile and a Group. When there are one or more fields defined in both the Group and the Profile, the data for those fields in the Profile is always used and the data for those fields in the Group is ignored.

[0115]Network Mode. The following are the network modes supported by the SPP station. A single mode is defined within each Group as part of System Configuration.

[0116]Static IP Mode. If Static IP Mode is set for a Group, that Group must define the following common data for the SPP stations within that Group:

[0117] - Subnet Mask

[0118] - Gateway

[0119] Additionally, in Static IP Mode, the following station-specific data is defined for each station belonging to that Group:

[0120] - Fixed IP Address.

[0121]DHCP Mode If DHCP Mode is set, SPP stations within that Group operate using an IP Address obtained from a DHCP server as a DHCP client in accordance with RFC 2131. DHCP Mode does the following:

[0122]* Provisions the SPP station with an IP Address from a DHCP server.

[0123]* Provisions the SPP station with a Subnet Mask from a DHCP server.

[0124]* Provisions the SPP station with a Gateway Address from a DHCP server.

[0125]* Provisions the SPP station with a TFTP Server Address from a DHCP server.

[0126] Additionally, the following station-specific data can be defined for each station in that Group:

[0127] - Fixed IP Address.

[0128]If a Fixed IP Address is configured, the station does not use DHCP mode.

[0129] In DHCP Mode, the SPP station depends on the presence of a working DHCP server to operate. In case a DHCP server is not found, the station will trigger a "DHCP Lost" alarm. During DHCP server loss, the SPP station can be configured to not make Page or Party advertisements over the network.

[0130]Master Allocation Mode. If Master Allocation Mode is set, the Group must define the following common data for the SPP stations within that Group:

[0131] - IP Address Pool

[0132] - Subnet Mask

[0133] - Gateway

[0134] Additionally, the following station-specific data can be defined for each station in that Group:

[0135] - Fixed IP Address.

[0136] In Master Allocation Mode, the IP Address Pool is a range of IP Addresses, for example “192.168.1.12 to 192.168.1.46”. While operating in this mode, the SPP station will depend on the Master Station for IP address allocation through the Command Channel. If the SPP station is the Master Station, it only uses a fixed IP address set within the Group configuration. It is the responsibility of the current Master Station to maintain the current address pool for Master Allocation Mode.

[0137] If a Fixed IP Address is configured and conflicts with the IP Address Pool, the address is reserved and cannot be allocated to the Pool. If a configuration change creates an IP conflict, the Master must resolve the issue by reallocating addresses as necessary.

[0138] Master Allocation Mode can preferably only be used, for example, with SPP stations running in Mutual Provisioning Mode, where there is a Master Station currently designated to perform IP allocation.

[0139]Configuration Modes. The SPP station supports two configuration modes. The mode is controlled using the Profile Selector Switch (e.g., the Station and Group number selector switches shown in Figure 10 which can be, for example, implemented as hexadecimal (0-F) rotary switches on the main board 32 ). When the Profile Selector Switch is set to 0, the SPP station must use Manual Configuration Mode, for example. When the Profile Selector Switch is set to 1 to 255, the SPP station must use Mutual Provisioning Mode, for example.

[0140]Manual Configuration Mode. This mode is intended to allow an SPP station to operate as a standalone device, possibly within a pre-existing and/or third-party multicast-based audio system. It is also intended for use during the initial configuration for Mutual Provisioning Mode (see below).

[0141]In Manual Configuration Mode, the SPP station uses only Group 0 and Profile 0 from its current System Configuration. The SPP station does not share or accept System Configuration data on the Command Channel from other SPP stations in this mode. Manual Configuration Mode does not use Mutual IP Allocation and does not use or need “Master” stations.

[0142]Mutual Provisioning Mode. This mode is intended to allow all SPP stations within a system solution to mutually maintain their runtime configurations, without the support of a fixed central point such as a server, and without the need for human administration.

[0143] Mutual Provisioning Mode is intended to optimize the initial configuration process by separating the system design/planning and system installation stages of a customer solution and is also intended to minimize the cost and effort required to maintain/replace defective SPP stations in an existing system.

[0144] In Mutual Provisioning Mode, SPP stations operate using the System Configuration obtained from other SPP stations already on the network using the Command Channel.

[0145]Feature Summary for Mutual Provisioning Mode:

[0146]* All stations share a System Configuration.

[0147]* Two Selector Switches to control Group and Station Number.

[0148]* Fixed Multicast Address/port “Command Channel” used for configuration control and proliferation between stations. Factory configurable.

[0149]* 16 Groups, each with configurable fields.

[0150]* 16 Profiles, each with configurable fields.

[0151]* Static, DHCP or Mutually Allocated IP Settings.

[0152]* Mutual Provisioning used for configuration only, does not affect/is not necessary for actual station operation.

[0153]* System-wide control via “Master” station. Master Station (and backups) determined by System Configuration.

[0154]* System wide interface via Master Station. The IP Address determined according to the configured Network Mode, can be configured as Static within DHCP or Master Allocation Mode if necessary.

[0155]* Individual SPP Stations can be isolated from Mutual Provisioning Mode by setting the Station Number and the Group Number changes to “0”.

[0156] As a basic illustrative event flow for configuring a system when using Mutual Provisioning Mode is as follows:

[0157]Generate System Configuration. SPP stations that are operating in Mutual Provisioning Mode obtain their configuration information from System Configuration. System Configuration captures the configuration of all SPP stations within the system. This is the design point of the solution and must occur before the actual installation of the SPP stations. Typically, an Administrator would generate the System Configuration as a file using a text editor, to be subsequently applied to the first SPP station.

[0158]Connect & Configure the First SPP station. The Administrator adopts the first SPP station and sets the Group Selector Switch to 0 and the Station Number Selector Switch changes to 0. This places the station in Manual Configuration Mode. This station is then connected to a laptop/PC using a network cable and powered.

[0159] An Administrator must interface with this station and update the existing System Configuration or load a previously generated System Configuration File. As part of this, the Administrator must define a new System Designation, e.g. “GTUK Burton” and System Version, e.g. “1”. Whenever the System Configuration is changed in any way, the SPP station must validate the entire configuration to ensure that the configurations are compatible. If the file is valid, the SPP station must generate a new MD5 Checksum against that file which can be used as an identifier.

[0160] Once the new System Configuration has been applied to the SPP station, the Group/Number Selector switches must be set to their appropriate values. This should trigger a reconfiguration on the station that will apply the settings according to the System Configuration for that Station Name, for example, "0.1".

[0161] Once the reconfiguration process has been completed, the SPP station (hereinafter known as Station 0.1, as it now has a Station Name) announces itself on the Command Channel using the AN command, which contains the System Designation , the Group Number and the Station Number.

[0162] Duplicate Station Detection. The AN command is used to announce the presence of an SPP station that has just been activated or has just had its group and/or station number configuration changed. When other stations in the system receive the AN command, they respond with a DS command if they share the same Number of Groups, Number of Stations, System Designation. The DS command indicates to the initial SPP station that there is a duplicate station in the system. In this case, the first SPP station must trigger a “No Configuration” alarm.

[0163]The station then listens on the Command Channel for the KA command from the Master Station. If the KA command is not received within 3 times the defined Keep Alive period, and if that station is included in the Master List, that station issues an NM command to the command channel (see later) to announce its Group Number and Station in the System to other Master Stations present. Since this is the first station, there will be no response and therefore it must designate itself as the "Master" station for the overall System. If this station is using Master Allocation Mode, the station must also assign itself an IP Address from an address range defined by the Administrator as part of its Group.

[0164]Master Station. The Master Station is an SPP station that has been assigned the role of maintaining the system configuration on behalf of all SPP stations within the system. The Master Station also serves as an interface point for the Administrator.

[0165]Keep Alive. During runtime, the Master Station uses a "Keep Alive" mechanism to inform other SPP stations that it is still present and functional within the system. The “KA” command is used for this purpose (see Command Channel Table above). This command is repeatedly issued by the command channel at an interval equal to the Keep Alive period (factory configured value) by the Master Station. Referring to Figure 19, The KA command contains the Group Number, Station Number, System Designation, System Version, and Configuration Checksum of the Master Station that issued it. SPP stations will ignore the KA command if it contains a System Designation that does not match their own (except for SPP stations with the designation "FACTORY").

[0166]Introduction of New SPP Stations. The installer takes a second SPP station (disconnected and powered off) and sets the Group Number Selector Switch to 0 and the Station Number Selector Switch changes to 2. The installer then connects this second SPP station (hereinafter referred to as the Station 0.2) to the network with the Master Station already configured and connected.

[0167] Referring to Figure 20, the second SPP station announces itself on the Command Channel using an AN command. It then waits for a KA command from the Master Station.

[0168] When the KA command is received, Station 0.2 compares its own configuration checksum with the checksum received from the KA command. If the checksums match, Station 0.2 should configure itself according to the data for station name "0.2" in its own System Configuration. If the checksums are different, Station 0.2 will compare its System Version to the System Version received in the KA command. If Station 0.2 has a lower System Version number than Station 0.1, Station 0.2 requests System Configuration data from the Master Station using an RD command. The Master Station responds to this command with a PD command to provide configuration data.

[0169] Station 0.2 stores the received System Configuration in non-volatile memory, recalculates the checksum on the received System Configuration and compares it with the checksum originally received from the Master and the checksum that was received with the configuration itself . If all checksums match, Station 0.2 applies the received System Configuration. It then reconfigures itself according to the data for the station name "0.2" in its System Configuration and deletes the old configuration.

[0170] If the checksums do not match, the second station will generate a request for the data again and repeat this process until the checksums match. If this process fails 3 times, the station should trigger a “No Configuration” alarm.

[0171]Finally, if Station 0.2 is included in the Master List of your new System Configuration, has the same System Designation as the current Master Station, and is higher in Order of Preference than the current Master Station, the same must inform the current master using an NM Command (see later) and then assume the role of Master. Any relevant volatile data, such as assigned IP addresses, held by the current Master must be transferred to the new Master in this case.

[0172] Configuration Maintenance and Updates. The command announces the current configuration checksum calculated from your System Configuration to other SPP stations in the system. Any SPP station that does not have a corresponding configuration checksum, even if it has been used previously, must request a configuration update via an RD command which the Master will respond with a PD command. This way, any configuration changes can be proliferated throughout the entire system, while the Administrator must only apply changes to the Master Station.

[0173] If Station 0.2 is operating in Master Allocation Mode, the Master Station must assign it an IP address from its corresponding Group Pool as part of this process. The SPP station then adopts the settings according to the System Configuration.

[0174] The same process must be followed to connect subsequent SPP stations to the network. In each case, the appropriate values must be configured with the Station Number and Group switches for each connected station.

[0175]Loss of Master. In case the Master does not send the KA command within 3 times the defined Keep Alive period, the remaining SPP stations included in the Master List of that System must issue an NM command to the command channel to announce the Group and Station number. After all remaining SPP stations contained in the Master List issue their command, or after a set timeout, the new SPP Master station must be determined using the Order of Preference. The new Master should then begin issuing KA commands to the Command Channel normally.

[0176] With reference to Figure 21, if the recently negotiated Master then loses connection for any reason, the same behavior will repeat if the KA command is not received within the defined Keep Alive period. Therefore, the overall system must always have a station present to facilitate configuration updates and provide an interface to the Administrator.

[0177]System Power Loss / Simultaneous Startup. SPP stations maintain awareness of the currently configured Master in non-volatile memory. If a System Power Loss event occurs, stations must be initialized and announced on the Command Channel using an AN command. They must then wait for a KA command from the Master. If the Master has been permanently disconnected during the System Power Loss event and the KA command is not received within 3 times the defined Keep Alive period, the remaining SPP stations in the Master List must negotiate with each other to decide which SPP station should be assigned the new Master Station using the same Master Loss method (see above).

[0178]Multi-Master Negotiation / Master Failover. When multiple Master Stations with the same System Assignment are operating in Mutual Provisioning Mode and are located across the Command Channel, the SPP stations in the Master List negotiate with each other to decide which SPP station should be assigned the new Master Station using the same method as Master Loss (see above).

[0179] If two separate systems (i.e., two groups of SPP stations with different System Designations) are merged/connected in this manner, the stations in each respective system will not attempt to override one another's configuration. In fact, each station must always remain part of its own System according to its System Designation until such time as it is reset to the FACTORY designation.

[0180] If using Master Allocation mode, the Master Station must reallocate IP addresses to resolve any IP or configuration conflicts that are detected (i.e., if two separate SPP station networks with separate Master Allocated IP pools had been connected).

[0181]Configuration Missing. If the selected Station Group or Station Number is not configured within the current System Configuration immediately after this configuration is applied, the SPP station must trigger the "No Configuration" alarm.

[0182] Master Introduction of a second System. If the SPP station is connected to and powered by a System Configuration from a Second system and is included in the Master List of its own System Configuration, the existing Master Station will not attempt to overwrite its configuration as the System Assignment will be different. Similarly, other SPP stations in the first system will not make configuration requests to the Master Station in the second system, except that all Master Stations in the first system lose network connectivity.

[0183] This is a design choice to prevent SPP stations moved from other systems from corrupting the existing System Configuration. This ensures that the worst-case scenario for a conflict will be that a single station is incorrectly configured. The exception to this rule are SPP stations with the system designation "FACTORY". These SPP stations will allow any Master to provide them with a new System Configuration until a new System Configuration changes their System Designation to another value.

[0184]Additional Maintenance. When changes to an established System Configuration need to be made, the Administrator must interface with the current Master Station to make the necessary changes. This must be done via a Telnet connection. The IP Address of the SPP station used for this purpose will depend on the chosen network mode, but in all cases it can be configured manually as part of System Configuration so that it is known.

[0185] When the System Configuration is updated, the Master Station KA command must include the new Checksum and System Version. Other SPP stations with the same System Designation as the Master Station, a different Configuration Checksum, and a lower System Version than the Master Station must request a configuration update from the Master Station using an RD command.

[0186]Initial Configuration. Configuration Manager loads System Configuration during boot into memory. The SPP station omits valid hardcoded configuration values during initialization if a System Configuration is not present. The SPP station triggers a “No Configuration” alarm (e.g. using the Health Monitor) if there is no onboard configuration present.

[0187]Reset to Factory Defaults. The SPP 20 station supports Factory Reset as an update function. The SPP station stores a Factory System Configuration in non-volatile storage so that it continues between shutdowns. When invoked, the Reset to Factory Defaults function replaces the currently running System Configuration with the Factory Default System Configuration and applies the new System Configuration settings.

[0188] Configuration Update Request. Configuration Manager supports Configuration Update Requests. Configuration Manager accepts requests for single Configuration Field updates to the existing System Configuration or for a Factory Reset.

[0189]User Account &Access Levels. System Configuration maintains a list of 5 user accounts that are used to authorize access and configuration modification on the SPP station, as well as authorize commands issued to the SPP station. Each user account must consist of:

[0190]Username. Unique Identifier. Values: 32-character string.

[0191]Password. Values: 32-character ASCII string.

[0192] Access Level. Values: 1 to 5.

[0193] Access Levels. System Configuration maintains a list of 5 Access Levels that are referenced by User Accounts. An Access Level defines a permissive list of which configurable parameters/commands can be changed or invoked by a User with that Access Level. Any parameter/command not included in that Access Level cannot be accessed by that access level. Additionally, each Access Level consists of:

[0194] Access Level. Unique Identifier. Values: 1 to 5.

[0195] Each SPP 20 station also has a special User Account with Access Level 0. This account is a reserved account intended for manufacturing use. This access level has no restrictions imposed on it. The account preferably always exists in the system, and should be automatically generated by the SPP station in case it is missing from the configuration.

AUDIO MANAGER

[0196] Still referring to Figure 11, the SPP station 20 supports an Audio Manager process 106. The Audio Manager is responsible for routing audio to and from hardware peripherals. Audio Manager 106 implements, for example, Audio Manager State Diagrams (and associated substates) described herein with reference to Figures 12 to 15

[0197] Referring to Figure 12, the Audio Manager manages audio routing to/from peripherals and channel priority negotiation for the Page Line.

[0198] Figure 13 illustrates a state diagram for a Paging Reproduction substrate in Figure 12. For example, initially the Pressure Bar is released, and the Telephone Handset is on Hook. The SPP station receives audio from the Page Line at a higher priority than that currently being played at the amplifier. The SPP station for routing lower priority input Line Page audio to the Amplifier. The SPP station mixes the highest priority input Line Page audio streams and routes the mixed audio to the Amplifier.

[0199] Figure 14 illustrates a state diagram for a Party Line Conference substrate in Figure 12. For example, initially the Pressure Bar is released, and the Telephone Set is on Hook. The User lifts the Telephone Device. The SPP station begins sampling audio into the Microphone. The SPP station routes the sampled audio to the selected Party Line. The SPP station routes the audio received on the selected Party Line to the Handset.

[0200] Figure 15 illustrates a state diagram for a Line Page Advertisement substrate. For example, initially the Pressure Bar is released, and the Telephone Handset is on Hook. The User presses the Pressure Bar. SPP station 20 for routing audio received on the selected Page Line to the Amplifier. The SPP station routes the audio received on the selected Page Line to the Handset. The SPP station mixes the remaining highest priority input Line Page audio streams and routes the mixed audio to the Amplifier. As an exception, the SPP station can be configured to defer to the currently selected Page Line while audio is being received on that Page Line. The SPP station plays the busy tone in the headset until the telephone set 22 goes on-hook or the Pressure Bar is released. SPP station 20 otherwise routes the pre-announcement tone to the handset for a fixed time. SPP station routes the pre-announcement tone to the selected Page Line for a fixed time. The SPP station begins sampling audio into the Microphone. The SPP station routes the sampled audio to the selected Page Line. As another exception, the User can change the selected Page Line. The SPP station is configured to defer to the recently selected Page Line while audio is being received on that Page Line. The SPP station plays the headset busy tone instead of audio/pre-announcement until the telephone handset goes on-hook or the Pressure Bar is released.

[0201] Audio Transmission and Reception between stations. Still referring to the Audio Manager generally in Figure 11, the SPP station transmits and receives audio over an IP Network. The following will describe illustrative means through which audio is sampled and transmitted and received between SPP stations.

[0202]Audio Sampling. Audio can be sampled at the Microphone and/or Auxiliary Audio Input as monaural PCM. The audio sampling rate can be fixed to a rate of at least 8000Hz. A higher default sample rate can be used to achieve higher audio sampling quality subject to hardware and performance constraints. A sampling rate below 8000Hz is generally unacceptable. PCM data from each device can be stored in a separate circular buffer (i.e., one buffer per device). The Auxiliary Audio Input PCM should only be used when the Auxiliary Audio Contact is Active.

[0203]Audio downsampling. When PCM audio is read from the circular buffer, it may need to be downsampled to a lower frequency before being compressed. This mechanism is necessary to match the chosen compression scheme for transmission and also for future development in the form of additional compression schemes. A given PCM audio stream may or may not need to be downsampled; this depends on the fixed sampling rate chosen and also the requirement of the compression scheme being used. The PCM is preferably not changed to a resolution lower than 8000Hz before compression.

[0204]Audio Compression. The sampled audio can be read from the circular buffer as entire 'frames'. Any partial frames (e.g. at the end of a conversation) can be filled with silence. The frame size depends on the compression scheme used. Each audio frame can be encoded using one of the following compression schemes as:

[0205]G.711 u-law,

[0206]G.711 a-law,

[0207]G.729.

[0208] It is understood that other compression schemes may be used. For example, higher bandwidth codecs can be used in conjunction with a compatible compression scheme. The compression scheme for compression use is configurable per input source (i.e. Microphone/Auxiliary Input).

[0209]Audio Transmission. Compressed frames are transmitted from an SPP station across the Network using RTP over IP at an auto-negotiated rate of 10 or 100MBit/s. Multicast addressing is used so that each packet can be received by multiple SPP stations. Each data packet is structured as shown in Figure 22, for example. Each layer of the package structure adapts to the relative RFC. Note that for a single packet, the IP layer can only adapt to RFC 791 (IPv4) or RFC 2460 (IPv6). The IP layer cannot adapt to both at the same time. SRTP (Secure RTP) could be used if data encryption was a desired feature.

[0210]Audio Destination. The Microphone's audio destination is determined by the software state of the SPP station, controlled by the Page Switch, Party Switch, and Press Bar. Auxiliary Audio is transmitted to the socket selected by Socket Page.

[0211]RTP Layer. This layer is the main mechanism behind transmitting and receiving audio with an SPP station. For the most part, the RTP layer of transmitted packets is structured according to RFC 3550. An example structure is provided below to illustrate that:

[0212]* some fields in the RTP layer are optional; the scope of an example implementation is captured here;

[0213]* the CSRC field is intended for use in a non-standard manner; It is

[0214]* Payload field size may vary between implementations.

[0215] The RTP layer of each packet can be constructed as follows:

[0216]V: Protocol Version. Values: 2.

[0217]Q: Filling. Not used. Values: 0

[0218]X: Extension. Not used. Values: 0.

[0219]CC: CSRC Count. Indicates the presence of the CSRC header. Values: 0, 1.

[0220]M: Marker bit. Not used. Values: 0.

[0221] Payload Type: Indicates the payload encoding format. Values: 0 (G.711 u-law) or 8 (G.711 a-law).

[0222]Sequence Number: Sequence Number. Incrementation of number indicating payload position in packet sequence. Values: 0 to 65535

[0223]Timestamp: Offset (ms) used to synchronize RTP during clock drift. Values: 0 to 4294967295.

[0224]SSRC: Unique RTP stream ID. Randomly generated. Values: 0 to 4294967295.

[0225]CSRC: Unique RTP stream ID. Configurable for Mutual Mute. Values: 0 to 4294967295.

[0226] Payload: Coded audio. The size may vary depending on the compression algorithm in use.

[0227] Each device has a configurable CSRC field that can contain a single value. Any other station with this value configured in its Mutual Mute List must ignore the audio from that SPP station.

[0228]Audio Reception (Network). Audio is received from network 40 by extracting payload data encoded within RTP packet streams on sockets that the SPP station is configured to listen to. The SPP 20 station can listen to up to 1 Party Socket and up to 8 Page Sockets simultaneously. The payload data of the selected Party Socket (according to the Party Line Selector Switch position) is buffered and ready for decompression. Simultaneously, payload data is buffered from the highest priority Socket Page as determined by the software state (e.g., the state diagrams in Figures 12 through 16) and configured priority assignments. Each Socket Page has a numeric priority value associated with it which can contain a value between 1 to 8. Each Socket Page must be configured with a unique priority value and this must be applied by validation. SPP stations may need to receive Page Announcements from areas outside their immediate communications group (i.e., the Page/Party channels they can transmit), such as emergency multicast announcements from other SPP stations or audio streams from external multicast. Therefore, up to 8 Page Sockets can be supported instead of just 4 Page Sockets.

[0229]Filtering. The payload data is not buffered, but instead is immediately discarded, if the value of the CSRC field matches a value contained in the Mutual Mute list at the SPP station, or, one of the header fields at the UDP or RTP layer does not match. fits one of the specified values (indicates incompatible stream configuration).

[0230]Audio Decompression. The payload in each RTP packet is decoded according to the compression scheme indicated by the Payload Type field within the RTP layer. This produces a monaural PCM frame of at least 8000Hz. A higher playback rate can be obtained (up to the sampling rate of the received data) by subjecting to hardware evaluation and performance constraints.

[0231] Identification. The SSRC field within the RTP layer is used to associate each PCM frame with an active 'channel' for mixing purposes. When a matching channel cannot be found, a new channel is created to store the new audio data. There is a maximum of 8 channels.

[0232]Buffering. Received PCM frames are stored in a circular buffer associated with the allocated channel. The buffer has a configurable size per user between 20ms to 2000ms in real time.

[0233] Mixing. When there is at least one frame available on each active receive channel, the oldest frame from each channel is mixed into a single 80-sample PCM frame. This frame is stored in a circular buffer associated with the receive socket ready for playback.

[0234]Reproduction. Audio is routed to the appropriate peripheral, as that socket receives priority (in the case of Page Audio) or becomes the selected Line (in the case of Party Audio). The details of where and when audio is routed to the headphone/amplifier are described above in conjunction with Figures 12 through 15.

[0235]General I/O (Input/Output) Manager.

[0236] The SPP station supports a General I/O Manager 108 that reads the Page Line Selector Switch, the Party Line Selector Switch, the Hook Switch, and the Auxiliary Audio Contact and maintains the input and output states. More generally, the General I/O Manager 108 is a process that is responsible for reading the electronic state of the various hardware peripherals as inputs and adjusting the state of the various peripherals as outputs. The General I/O Manager can implement, for example, the General I/O Manager State Diagram as shown in Figure 16.

[0237]Outputs. The General I/O Manager 108 supports requests to adjust the state of 6 configurable Outputs. The SPP station triggers each of these 6 peripherals based on its internal logic state and the activation conditions configured for that peripheral.

[0238] Each logical state can be combined for a different peripheral. When more than one state is used, a logical OR between the two states must be performed to determine the final output state of the peripheral.

[0239]The exception to this is the ON and OFF states. These states override all other states. ON AND OFF cannot be set for the same peripheral at the same time.

[0240] The activation conditions of each output in the SPP station 20 for this purpose are as follows:

[0241]* IDLE. When the SPP 20 station is in the Idle State (Telephone Set On Hook, Press Bar Pressed, no Page announcement in progress).

[0242]* RXPAGEANY. When the SPP station is receiving Page audio on one or more Page channels.

[0243]* RXPAGEn. When the SPP station is receiving Page audio on the Page channel specified by 'n' (1 to 8).

[0244]* TXPAGEANY. When the SPP station is transmitting Page audio on one of the Page channels.

[0245]* TXPAGEn. When the SPP station is transmitting Page audio on the Page channel specified by 'n' (1 to 8).

[0246]* PARTY. When the SPP station is in a Party line conference.

[0247]* PARTYn. When the SPP station is in a Party line conference on the line specified by 'n' (1 to 5).

[0248]* OFFHOOK. When SPP station Hook Switch is in Off Hook state.

[0249]* ONHOOK. When SPP station Hook Switch is in On Hook state.

[0250]* FAULTY. When there are one or more Events recorded that indicate a failure state.

[0251]* HEALTHY. When there are no recorded Events that indicate a failure state.

[0252]* ON. Set the output to the Active state.

[0253]* OFF. Set the output to the Inactive state.

[0254]Inputs. The General I/O Manager 108 supports requests to read the functional state of system inputs. The supporting entries are:

[0255]* Party Key

[0256]* Page Key

[0257]* Hook Wrench

[0258]* Press bar

[0259] Whenever the General I/O Manager receives a request for the functional state of one of the above inputs, the General I/O Manager 108 must read that device and return the correct value.

[0260] Amplifier Status. The Amplifier has two states that are controlled using a relay. The relay is triggered from a GPIO pin. The General I/O Manager supports two Amplifier states:

[0261]* SPKR

[0262]* AMP

[0263] Whenever the General I/O Manager 108 receives a request to set the state of the Amplifier relay to one of the items above, it consequently activates the corresponding pin. Typically, the Amplifier State is triggered by the Health Monitor.

TELNET CLIENT

[0264] Still referring to Figure 11, the SPP station supports a Telnet service as a human-usable interface. The Telnet service allows a Telnet 112 client to form a TCP connection to the SPP station and interface with the Internal Command System. Each Telnet Client challenges each new connection to present a valid login. A login is valid if the Requester enters the strings corresponding to those stored in the SPP station configuration fields for User Login and User Password.

SNMP CLIENT (SIMPLE NETWORK MANAGEMENT PROTOCOL).

[0265] Still referring to Figure 11, the SPP station hosts an SNMP Agent for reporting changes in health status to and for handling health status requests from an SNMP Management System. This Agent maintains a Management Information Base to expose relevant health status information.

[0266] SNMP Client 114 supports SNMP trap to report changes in health status as asynchronous events to the SNMP Management System. The SPP Client does not support configuration provisioning via SNMP. The SPP Client recovers the system state using the Internal Command System. Each SNMP Client challenges each new connection to present a valid login. A login must be valid if the Requester enters the strings corresponding to those stored in the SPP station configuration fields for User Login and User Password. The SNMP Client maintains the Management Information Base (MIB) for the SPP station.

TFTP CLIENT (TRIVIAL FILE TRANSFER PROTOCOL)

[0267] Still referring to Figure 11, the SPP station supports a TFTP Client 116 to transmit/receive firmware and configuration between a TFTP server and the SPP station. The TFTP Client reads and writes data to the SPP station through the Internal Command System.

[0268]Configuration Updates. The TFTP Client 116 allows an Administrator to transmit configuration and/or MPG data as a plain text file to the SPP station 20. Configuration files may consist of part or all of the fields. The TFTP Client will attempt to update only the Configuration fields that are specified within the configuration file used. The TFTP Client performs validation on the file before applying configuration updates. If any field fails to perform validation, the TFTP Client rejects the entire update.

[0269]Configuration Recovery. TFTP Client 116 allows an Administrator to retrieve MPG data from the SPP station. The TFTP Client also allows an Administrator to retrieve configuration settings from the SPP station as a plain text file.

[0270]Firmware Updates. The TFTP Client 116 provides a mechanism for the SPP station to retrieve a firmware update from a TFTP server for self-updating. Upon a successful firmware download, the SPP station performs a reboot to apply the new firmware version.

[0271]Authentication. Each TFTP Client 116 challenges each new connection to present a valid login. A login must be valid if the Requester enters the strings corresponding to those stored in the SPP station configuration fields for User Login and User Password.

[0272]File Macros. The TFTP Client supports update file macros. The supported macros are:

[0273]TFTP Boot Configuration Update. The SPP station supports an option to perform TFTP configuration updates upon boot. When this option is enabled, the TFTP Client attempts to perform a configuration update after the SPP station is initialized.

[0274]TFTP Timed Configuration Update. The SPP station supports TFTP timed updates. When this option is enabled, the TFTP Client attempts to perform a configuration update at a defined time. The SPP station also supports a TFTP update interval. When configured, the TFTP Client attempts to update the configuration at an interval after the time set for the Timed Configuration Update. The interval is configurable in hours and minutes.

HEALTH MONITOR

[0275] Still referring to Figure 11, the SPP station 20 supports a Health Monitor 110 as a software service. The Health Monitor 110 is responsible for monitoring a set of internal conditions at the SPP station. Health Monitor is also responsible for logging Events. Health Monitor also monitors the internal system process to ensure it is still functioning. This is done by a simple request-response mechanism for each process.

[0276]Heartbeat LED. The Health Monitor 110 triggers a heartbeat LED. The LED should cycle at a constant rate of 500ms on, 500ms off. This function serves as an indication that the software is not stopped. If any designated internal service fails, then the heartbeat function should cycle at a constant rate of 250ms on, 250ms off. If the Heartbeat LED stops working, it indicates that the Health Monitor is stopped.

[0277]Events. The SPP station supports Event logging. An Event is defined as something that occurred that the SPP station detected and recorded. Each Event is recorded along with a timestamp. For example, an Event may be logged whenever one of the following occurs:

[0278] Figure 18 provides an illustrative state diagram of the Health Monitor 110 as it continuously monitors the current health state of the total system, maintains the current system health state, handles requests for health state information, and generates health status reports.

GLOSSARY

[0279]CRC. Cyclic Redundancy Check.

[0280]DHCP. Dynamic Host Configuration Protocol: A client/server protocol that automatically provides an Internet Protocol (IP) host with its IP address and other configuration information.

[0281]EMAC. Ethernet MAC.

[0282]Event. An incident that SPP Station detected and recorded in an internal log.

[0283]Telephone Device. Physical container for Headphone, Microphone, Hook Switch.

[0284]IP. Internet Protocol.

[0285]IP-PBX. Private Internet Protocol Telephone Switching Center.

[0286]IT. Information Technology

[0287]LAN. Local network.

[0288]LED. Light emitting diode

[0289] Raise the Telephone Device. Remove the telephone set from its base (e.g. hook).

[0290] MAC. Media Access Control; The MAC data communications protocol is a sublayer of the OSI data link layer (layer 2).

[0291]Master. The Master Station currently active for Mutual Provisioning

[0292]Off the Hook. The telephone set has been removed from its base (e.g. hook).

[0293]On the Hook. The Telephone Device was placed on its base.

[0294]Page Line. One of the 4 broadcast channels.

[0295]Advertisement Page. A one-way audio broadcast to one or more SPP Stations using a Page channel.

[0296] Page Line Audio. Audio received on a Page channel (network or auxiliary).

[0297]Party Line. One of 5 conference channels.

[0298]Party Line Conference. A conversation between two or more SPP Station users using a Party channel.

[0299]PCB. Printed circuit board.

[0300]PCM. Pulse Code Modulation.

[0301]Replace Telephone Device. Place the telephone handset on its base (e.g. hook).

[0302]RFC 3550. Internet Standards Tracking Protocol. See https://www. ietf.org/rfc/rfc3550.txt or http://www. rfc-base.org/txt/rfc-3550.txt.

[0303]RTP. Real-Time Transport Protocol.

[0304]SIP. Session Initiation Protocol.

[0305]SNMP. Simple Network Management Protocol.

[0306]Socket. An IP address and port combination used to send/receive RTP.

[0307]SPP. Serverless Page Party.

[0308]SRAM. Static Random Access Memory.

[0309]Station Clock. Internal timekeeping process.

[0310]TCP. Transmission Control Protocol.

[0311]TFTP. Trivial File Transfer Protocol: A simple synchronized sequence file transfer protocol that allows a client to check out or place a file on a remote host.

[0312]UART. Universal Asynchronous Receiver/Transmitter.

[0313]UDP. User Datagram Protocol.

[0314]VoIP. Voice over Internet Protocol (IP)

[0315]Zone. A pre-configured Page Line Socket.

Additional modalities and implementations

[0316] Illustrative embodiments of the present invention have been described with reference to operations on a programmable device such as a Page/Party station or VoIP phone or server for station configuration or health monitoring in an internal communications system. It will be understood, however, that the present invention may also be embodied as computer-readable codes on a computer-readable recording medium. Computer-readable recording medium is any data storage device that can store data that can then be read by a computer system. Examples of the computer-readable recording medium include, but are not limited to, read-only memory (ROM), random access memory (RAM), CD-ROMs, DVDs, magnetic tapes, floppy disks, optical data storage device. It is anticipated that aspects of the present invention may be embodied as carrier waves (such as data transmission over the Internet via wired or wireless transmission paths). The computer-readable recording medium may also be distributed across networked computer systems so that the computer-readable code is stored and executed in a distributed manner.

[0317] The components of the illustrative devices, systems and methods employed in accordance with the illustrated embodiments of the present invention can be implemented, at least in part, in a digital electronic circuit set, analog electronic circuit set, or in hardware, firmware , software or computer hardware, or combinations thereof. These components may be implemented, for example, as a computer program product such as a computer program, program code, or computer instructions tangibly embodied in an information carrier, or in a machine-readable storage device, for execution by , or to control the operation of a data processing apparatus, such as a programmable processor, a computer, or multiple computers. A computer program may be written in any form of programming language, including compiled or interpreted languages, and may be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program can be deployed to run on one computer or on multiple computers at one location or distributed across multiple locations and interconnected by a communications network. Furthermore, functional programs, codes and code segments for carrying out the present invention can be easily interpreted within the scope of the invention by programmers skilled in the art to which the present invention belongs. The method steps associated with illustrative embodiments of the present invention may be performed by one or more programmable processors that execute a computer program, code, or instructions to perform functions (e.g., operating on input data and/or generating an output). The method steps may also be performed by, and the telephone apparatus of the invention may be implemented as, a set of special purpose logic circuits, for example, an FPGA (field programmable gate array) or an ASIC (application integrated circuit). specific).

[0318] Processors suitable for executing a computer program include, by way of example, general and special purpose microprocessors and any one or more processors of any type of digital computer. Generally, a processor will receive instructions and data from either a read-only memory or a random access memory or both. The essential elements of a computer are a processor to execute instructions and one or more memory devices to store instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, for example, magnetic, magneto-optical or optical disks. Suitable information carriers for embodying computer program instructions and data include all forms of non-volatile memory, including by way of example, semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g. internal hard disks or removable disks; magneto-optical discs; and CD-ROM and DVD-ROM discs. The processor and memory may be supplemented by, or incorporated into, a set of special purpose logic circuits.

[0319] The description and figures presented above are intended by way of example only and are not intended to limit the present invention in any way, except as set forth in the following claims. It is particularly noted that those skilled in the art can easily combine the various technical aspects of the various elements of the various illustrative embodiments that have been described above in many other ways, all of which are considered within the scope of the invention.

APPENDIX

[0320] The following illustrative configurable fields must be internally configurable at the SPP station within a System Configuration. Some fields are only configurable by certain users. Some fields are limited to Profiles or Groups (for example, where P = Profile, G = Group).

[0321] The configuration file format may be, for example, a plain text file comprising Profiles and Groups. Each Profile and Group defined within the file can contain a subset of configuration fields. Table: Illustrative General Adjustment Fields:

[0322] Other fields can be adjusted for Audio settings, SNMP Agent settings, Output settings, Hook Switch settings and Press Bar State Control, among others.

Claims (15)

1. Internet Protocol (IP)-based station that provides at least one of Page announcement and Party line conferencing relative to other IP-based stations, the IP-based station connected to other IP-based stations on a network that supports multicast and point-to-point communication, the IP-based station CHARACTERIZED by the fact that it comprises: a network interface for connecting the IP-based station to the network; at least one selector switch configured to select from a plurality of Party lines when the IP-based station is configured to transmit and receive audio in Party line conference with other IP-based stations, and from a plurality of Page lines when the IP-based station is configured to transmit and receive Page advertisements relative to the other IP-based stations, the Page lines being assigned to respective Party line sockets and the Page lines being assigned to respective Page sockets in accordance with a configuration of system; and a processing device that operates in a mutual provisioning mode to configure the IP-based station to provide Page announcement and Party line conferencing operations using Voice over Internet Protocol (VoIP) on the network, wherein the mutual provisioning mode allocates multicast addresses to designate at least one of the respective Page sockets and respective Party line sockets used by the IP-based station and the other IP-based stations in accordance with the system configuration, and the IP-based station once configured , operates to listen to their Page sockets configured for incoming audio, and to transmit audio on their respective Page sockets when designated by system configuration, and to participate in Party line conferencing on their respective line sockets partially when designated by system configuration. and to participate in Party line conference on respective Party line sockets when designated by system configuration; wherein, during mutual provisioning mode, at least one of the IP-based station and the other IP-based stations is provided with the system configuration at startup and operates as a master station, and the IP-based station and the other other IP-based stations are operable to use a designated multicast address as a dedicated channel, the processing device being configured performs at least one of: sending system configuration on the dedicated channel when the IP-based station is the master station, and receiving the system configuration via the dedicated channel from one of the other IP-based stations operating as the master station. 2. IP-based station according to claim 1, CHARACTERIZED by the fact that the processing device is configured to operate the IP-based station as a master station in relation to the other IP-based stations and maintains the system configuration . 3. IP-based station according to claim 1, CHARACTERIZED by the fact that the system configuration comprises the multicast address assigned to a dedicated channel used by the IP-based station and the other IP-based stations, and the station IP-based station operating as a master station can listen on the dedicated channel for an advertisement provided on the dedicated channel by another IP-based station and send responses to that IP-based station over the dedicated channel. 4. IP-based station according to claim 2, CHARACTERIZED by the fact that the system configuration comprises a list of master stations, and the processing device is programmed to negotiate with other IP-based stations in the master list to designate one of these as the new master station. 5. IP-based station according to claim 1, CHARACTERIZED by the fact that the network interface is at least one of an Ethernet cable interface and a WiFi interface. 6. IP-based station according to claim 1, CHARACTERIZED by the fact that it additionally comprises a local energy source. 7. IP-based station according to claim 1, CHARACTERIZED by the fact that the IP-based station is configured for at least one of IPv4-enabled communications and IPv6-enabled communications with the other IP-based stations. 8. IP-based station according to claim 1, CHARACTERIZED by the fact that the audio transmitted and received through the IP-based station comprises a real-time transport protocol (RTP) layer of packets structured in accordance with the Internet standard RFC 3550. 9. IP-based station according to claim 1, CHARACTERIZED by the fact that the system configuration comprises at least two virtual zones defined using station identifiers designed to uniquely identify the Page Party station and the other Page Party stations and identifiers of zone, each of the zone identifiers being assigned identifiers selected from the station identifiers. 10. IP-based station according to claim 1, CHARACTERIZED by the fact that the processing device is configured to operate the Page Party station as a master station when the Page Party station is identified as a master station in the system configuration , and to control the Page Party station to communicate over the command channel when one of the other Page Party stations is designated as a master station in the system configuration. 11. IP-based station according to claim 1, CHARACTERIZED by the fact that the system configuration comprises a system designation that identifies a system and respective station identifiers for each Page Party station and the other Page Party stations deployed in that system. 12. IP-based station according to claim 11, CHARACTERIZED by the fact that the system configuration further comprises a group identifier for each of one or more groups of Page Party stations deployed in the system and identifiers designated among the identifiers of stations that are assigned to each group, each group having a corresponding group configuration comprising configurable fields within the Page Party stations that are used for each of the Page Party stations assigned to that group, and the system configuration comprising a profile for the Page Party station comprising the system designation, a group number for the group to which the Page Party station is assigned, and the station identifier of the Page Party station. 13. IP-based station, according to claim 1, CHARACTERIZED by the fact that the system configuration comprises a fixed IP address for the Page Party station. 14. IP-based station, according to claim 1, CHARACTERIZED by the fact that the master station allocates an IP address to the Page Party station. 15. IP-based station according to claim 1, CHARACTERIZED by the fact that the Page Party station operates as a slave station to one of the other Page Party stations operating as the master station, and the processing device is configured to control the Page Party station to, upon initialization, send an announcement to the master station via the dedicated channel and to receive system configuration from the master station via the dedicated channel.