Beukelman and Mirenda estimated that approximately 1. Enderby, Judge, Creer, and John estimated that 0. According to the National Survey of Children With Special Health Care Needs — , the estimated prevalence of children with special health care needs who have a speech difficulty is 2. Of these children, 7. The majority of children in this study had a primary diagnosis of developmental delay, autism, or pervasive developmental disorder PDD. SLPs play a central role in the screening, assessment, diagnosis, and treatment of persons requiring AAC intervention.
Aided Communication. Aided Comm has 4 integrated parts. Selection Methods Selection methods are the ways a user chooses the symbols. Strategies The strategies are the action plans in place to encourage success. Pros and cons of aided communication Tools with pictures or icons are easy to understand by most partners. The user needs to be able to identify, locate and select the pictures or icons.
Problems occur if the pictures get misplaced or lost. This assumes that all partners will understand the language of the device. These speech generating devices SGDs can be picture, icon, or text-based.
The user needs to know how to activate the device. The user should know how to maintain the device. Tools that use technology are popular. Technology breaks. We should consider having low-tech options and a backup plan.
Print Materials. Connected Computer Aided Communication David Sloan. A short summary of this paper. Connected Computer Aided Communication. Indeed research shows that al output of electronic communication aids is limited to literacy- users, in general, are limited to short or one word utterances; they based devices, even though most users are not literate. Current show little motivation and in many cases stay passive when it systems for pre-literate users are dependent on carers for input and comes to communicating with others [9].
Utilizing the Social Web and the computing power afforded by online connectivity 2. This is an area of high potential for impact and in- Supporting language development for individuals with congenital novation as recent projects have shown.
Instead carers and users are trained to use well-researched methods to organize vocabulary. Any concept of Keywords: WiFi Network, Augmentative and Alternative facilitating the automatic development of vocabulary, its retrieval Communication AAC , Personal narrative, Language develop- and indeed any long term access to once information is stored, is ment, Assistive technology, Disability, Cerebral Palsy, Mobile nonexistent.
The majority of this user group is pre-literate, de- in the research context. For example, Newell et al. In addi- such as Did Mary go to the store? Dempster [3] is working on tion, users need to know what vocabulary they wish to retrieve using NLG to support social interaction for adult AAC users with and in what order; this is a fundamental challenge when many various degrees of literacy.
An example of harvesting information users are in the process of developing language and communica- from the internet to increase access to vocabulary in this case to tion skills. Communication output is characterized by single inform word prediction is the Webcrawler project [4].
These examples however do not address the need for symbol access for the majority of pre-literate users. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that 3.
Copyright However, the applica- An NLG system specifically designed to support language devel- tions remain isolated systems with little merging of functionality. The development of an infrastructure for data trans- ated using NLG technology.
Nine children with SSPI successfully fer between AAC devices with an openly available system archi- trialed the system in a special school. Standard-C SESs do not require the use of a dedicated receiver for receiving signalling information. The SES consists of a DCE data circuit terminating equipment providing the interface to the satellite network, and a DTE data terminal equipment, for example a personal computer which provides the user interface. For ship-to-shore message transfer, a message is formatted in the DTE and then transferred to the DCE for transmission.
In the shore-to-ship direction, the DCE receives the complete message from the radio channel before passing it to the DTE for the attention of the user. Enhanced Group Calls are also transmitted on this channel. Additional optional services are available within the system and may be offered by CESs. These services include access to electronic mail and message handling services X. The polling and data reporting services are primarily aimed at providing a service to remotely operated and land mobile terminals.
Standard-C protocol was not designed to be used in connection with land mobile data terminals but was designed only for maritime use. In addition, Standard-C was not designed for use or integration with computer aided dispatch applications. Thus, there is a need for a satellite communications system that provides effective communications for land mobile data terminals for use or integration with a computer aided dispatch application.
Conventional electronic mail and message handling services are not designed for extensive message transmissions in a satellite communication system. Service vehicles such as taxicabs, trucks, etc. Moreover, there is a need for providing advanced messaging capabilities where a variety of messages can be initiated by mobile terminals without providing excessive loading on the satellite.
Further, there is a need for providing advanced messaging capabilities where a variety of messages can be initiated by computer aided dispatch applications for effectively and efficiently controlling groups of mobile terminals.
The initiation of messages via the computer aided dispatch application will also result in effective and efficient controlling fleets of vehicles.
In view of the foregoing, there a feature and advantage of the present invention is in a low cost mobile communication system that provides efficient transport of user messages via a satellite network. Another feature and advantage of the present invention is in an electronic mail messaging system for transporting messages between a dispatcher and mobile communication terminals that uses predetermined message forms to minimize user efforts in generating and displaying mail messages.
Another feature and advantage of the present invention is in a satellite communications system that provides effective communications for land mobile data terminals for use or integration with a computer aided dispatch application.
Another feature and advantage of the present invention provides is advanced messaging capabilities where a variety of messages can be initiated by computer aided dispatch applications for effectively and efficiently controlling groups of mobile terminals. According to at least one aspect of the present invention, a mobile satellite system includes a satellite communication switching office having a satellite antenna for providing communication of a satellite message with a mobile communication system via a satellite, and a central controller communicating with the mobile communication system via the satellite communication switching office.
The mobile satellite system includes a satellite communication switching office having a satellite antenna for providing communication of satellite messages via a satellite. According to another embodiment of the invention, a method of managing and transmitting the customer messages between the CAD system and the mobile satellite system is provided.
The method includes the steps of supporting central controller communication services, satellite message communication services, and network management communication services, configuring middleware services for invocation, and receiving outbound messages from the CAD system, and formatting the outbound messages as application programmer interface API calls. The method also includes the steps of receiving inbound messages, interpreting the inbound messages, and delivering the inbound messages to the CAD system, invoking the middleware services via a library of middleware functions and the API calls, and performing message logging including logging control information.
The method also includes the steps of interfacing with a physical transport medium of the CAD system, providing an interface between the CAD system and the central controller and providing the CAD system access to the mobile satellite system, and configuring access information for accessing the central controller.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. The present invention provides a mobile communication system that sends and receives electronic mail messages to and from other stations in a satellite communication system.
The mobile communication system is designed to provide flexibility to users, while maintaining efficient terminal operations. The techniques described herein enable the mobile communication system to be implemented as a low-cost terminal requiring a minimal amount of memory. An overview of the overall satellite communication system and mobile communication system will be provided, followed by a more detailed description of the software interfaces and software functions of the mobile communication system.
The MCS provides services on the Mobile Communicator AMC application software so that it can communicate with a satellite modem and exchange data across the satellite network. These services include receiving messages from the application software and packaging them for delivery to the network, receiving data from the network and translating it into application messages, and providing services for the application to control and configure the transceiver.
The required communications services include receiving messages from the customer applications and packaging them for delivery to the network, and receiving data packets from the network and translating them for use by the customer's CAD systems. The satellite communication system 10 includes a dispatcher station 12, a satellite communication switching office 14, and a satellite network 16 for transporting satellite messages between the satellite communication switching office 14 and an adaptive mobile communication AMC system The AMC is implemented, for example, as a communications device on vehicle, for example a truck.
The dispatcher 12 is located at a customer premises, for example at a management office of a trucking company having a fleet of trucks. The dispatcher 12 sends and receives signals to and from the satellite communication switching office 14 via a leased communication line of a public packet switched network 20, for example a X. The satellite communication switching office 14 includes a satellite antenna 22, and a land earth station LES 24 that interfaces between the satellite antenna 22 and the public X.
Data packets carrying satellite messages received from the dispatcher 12 via the X. The communications requirements for the enhanced satellite communications protocol of the preferred embodiment is described in more detail in commonly assigned, copending application Ser. Satellite messages received from the mobile user via satellite network 16 by the LES have addresses identifying the recipient of the satellite message, described below.
If the intended recipient is the dispatcher 12, the LES 24 transparently forwards the received message byte stream plus a header from the satellite network 16 to a customer premise gateway CPG 26 at the dispatcher 12 via the public X. The CPG middleware 26a receives the byte stream from the X.
The CPG application software 26b converts the reassembled message into a format usable by a computer-aided-dispatcher CAD 28 resident at the dispatcher 12, and outputs the converted message to the CAD application The dispatcher 12 and AMC stations 18 communicate using proformas-template forms to be used by the sender and having data fields.
The AMC stations 18 have the proformas stored in memory, described below. Exemplary proformas include stop-over form used to inform the dispatcher 12 of an overnight stay, including date, time, and address fields.
The dispatcher 12 would receive record of the address where trucker will be staying that evening. Other proformas include free form text message , dispatch request, service request, etc. Each proforma may also include an acknowledge field.
The proformas minimize the amount of data that needs to be transmitted over the satellite network 16 by transmitting a form identifier, and the binary data to fill in the form. Hence, there is no need for labels, screen positions, format commands, etc.
The computer-aided-dispatcher CAD application 28 provides the dispatching and e-mail messaging functions in a graphic user interface to enable a dispatcher to manage the fleet of mobile units.
Proforma messages from the CAD application 28, described below, are converted and compressed by the CPG application software 26b from text data into a message carrying binary data. The message carrying binary data is then sent to the CPG middleware 26a software which converts the message to a byte stream for transmission to the LES 24 via the X.
The DTE 32 includes middleware software 36 and application software 38 controlled by a 25 MHz Intel or better microprocessor. The middleware software 36 provides a communications protocol enabling communication between the transceiver and the CPG. The AMC 18 has a proforma definition file in non-volatile memory. Hence, the Dispatcher 12 can create new proformas and download them via satellite to the mobiles 18, where the mobiles would accept the new form definitions and store them in the proforma definition file.
As described below, a user of the AMC 18 sends a message by selecting a proforma, filling out the form with the appropriate information and pressing the send button. In response to the send button, the application software 38 converts and compresses the text data into a message carrying binary data. The message carrying binary data is then sent to the middleware software 36 which executes the communication functions, including controlling the transceiver The middleware software supplies a byte stream of the mobile message to the transceiver, which transmits the byte stream to the LES via the satellite network.
The AMC 18 includes the communicator software 40 including the middleware software 36 and the application software Display data is output to a display 56, described in detail below. Additional peripheral devices may be connected to the DTE 32, including a printer 58 and a message notification device The notification device 60 is preferably a localized RF paging device having a range of meters for use when a driver is not within the vehicle. In such instances, the paging device 60 is activated when a satellite message having a predetermined priority level is received by the AMC In FIG.
The layered structure permits individual layers to be easily replaced or modified. For example, by including a separate middleware communications layer, different low level communications code can be easily inserted or modified to support different radio transceivers.
The network controller layer allows or facilitates the insertion or modification of different network functionality. The communications software integrates with the baselined application software. Various implementations of the customer site systems exist. The same version of communications software used to package data sent by mobiles must be used at the customer end to translate the packets, and vice versa. The communications software exists between the CAD applications and the network and does not require functional changes for different CAD implementations.
The three specific layers of the Communications Software include an applications layer, a device layer and a physical layer, illustrated in FIG. The applications layer provides the services of the Communications Software that is standard across installations. The device layer provides the functions for controlling and configuring the physical devices used in attaching to the MMS network.
This layer's services are tailored to the unique combination of installed devices. The physical layer provides the services to the device layer to physically connect to the communications hardware.
The design of the software makes use of this concept so that only the device and physical layers are different between installations, as well as the site specific configuration files. In those instances where the end systems' software components are being specifically discussed, they are referred to as "end systems.
The communications software provides services to the application software in order for it to communicate user messages across the MMS network. The communications device used for network access is fully controlled and configured by the application software through the communications software. The communications software supports exchanging these device specific data transactions through the Local Messages defined in Appendix A. In some instances, the communications software exchanges data with the device independent of any stimuli from the application software e.
The commands and mechanisms used for all of the above functions are device specific and will vary between installations. The communications software establishes connections with the network and maintains them to the extent required for the installation. The communications software does not need to actively maintain "sessions" or "circuits" since there is only one DCE servicing only one DTE i. Once the communications software has initialized, it communicates with the DCE and informs it that it is ready for communications.
The communications software monitors the health of the network and insulates the application from any adverse affects that may result from network degradation. The communications software polls the DCE to determine the health of the network. If the DCE responds with a system status message that indicates the network access is healthy, the communications software provides a Network Status Local Message to the AMC application indicating the network access status is "healthy".
Otherwise, a "failed" network status is provided to the application in a Network Status Local Message. Since the status messages returned from the device may have other information that may be useful to the application, the communications software also provides a Comm Status Local Message to the application whenever a status message is received from the device with the binary representation of the string returned by the device.
The communications software monitors these incoming DCE system status messages for indications that the DCE is unable to communicate over the network. When the communications software receives user messages from the application for transmission and it has detected that the DCE is currently unable to transmit over the network, the communications software stores the messages and provides them to the DCE when the DCE indicates that it is once again ready for communications via successful poll results.
When the communications software is terminated, it saves the current user message data structures and the assigned message ID information to the DTE's RAM Disk in a directory. When the communications software initializes, it reconstitutes its user message structures from any that exist in the directory on the DTE's RAM Disk.
This allows asynchronous message services whereby messages that were sent by the communications software, but not fully confirmed and removed from processing, can be tracked and processing completed if the communications software re-initializes. Additionally, the communications software use the assigned message ID information retrieved from the directory at initialization to ensure that it does not reassign any recently used message IDs after a software restart. The Mobile Communicator application software components require the MCS to accept their application messages and to ensure their appropriate transmission across the MMS network.
The communications software accepts messages from the End System, configures the communications device with the appropriate parameters, and sends the data to the DCE for transmission. The application software constructs the application messages it needs to communicate and also controls the transmission parameters.
Before providing data to the MCS to transmit, the application software assembles the user message buffer containing the contents of the application message as well as much of the MCS packet header.
In addition to the message buffer with the MCS packet header, the application also supplies the destination address type and physical value. The communications software uses the destination information supplied in these separate parameters for sending the message.
The communications software then verifies the contents of the data from the application and add other header fields. The application message portion of the packet is not altered by the communications software. The communications software verifies that the Message Type value inserted into the Message Type Packet Header field by the application software is the hexadecimal value This value indicates the message is a user message.
If no Message Type is indicated by the application or an invalid value is indicated, the communications software does not send the message over the network but, instead, provides a Message Status Local Message to the originating application with a status code indicating "Bad Message Type".
The communications software verifies that the Priority Level inserted into the Priority field by the application software is a valid numeric value between 0 and 9. If no Priority is indicated by the application or if the application indicated an invalid value, the communications software place a default value in the Priority field of the MCS packet header.
If no Acknowledgment Level is indicated by the application or an invalid value is indicated, the communications software places the default value in the Ack Level field of the MCS packet header.
The communications software verifies that the application software has provided a valid Destination Address Type and Destination Physical Value combination for the Destination Address Type and Destination Address Value parameters not the packet header fields. Data in the other packet header fields entered by the application software is not be altered by the communications software i. Appendix B indicates other fields included in the packet header to support enhanced features such as failed message retries, message acknowledgment, and message segmentation.
These fields are used by the communications software to support reassembly and decoding of the packet by the receiving communications software. After the communications software has received a message from the application software for transmission and completed packaging it within a MCS packet with the appropriate header information, the communications software provides a Message Status Local Message to the application indicating a Message Queued status.
In order to send the message across the network, the communications software sets the appropriate parameters in the data communications device and sends the packet to the device for transmission. Once a message has been handed off to the DCE for transmission, the communications software provides a Message Status Local Message to the application indicating a Message Transmitted status.
The software configures the message packet in little endian, reverse byte order before providing the binary data to the DCE for transmission across the network. The communications software provides the messages to the DCE in the appropriate order as specified by the message priority. Lower priority numbers indicate higher message importance and are provided to the DCE before messages with higher priority numbers.
Messages with a priority level of 0 or 1 are provided to the DCE with a "Distress" indication. All other messages have a "Normal" indication. To send a message, the communications software sends the appropriate standard message parameter commands to the DCE in order to set up the transmission according to the values in the Priority and Ack Level header fields, and the provided Destination Address Type and Physical Value parameters.
MMS customer uses of the system often impose widely varied responsibilities between installations. Many users may perform duties that require them to send messages much more often than other users. Meanwhile, some users may constantly receive messages and only need to send a message rarely. With this in mind. The parameter is defined as " send actions per receive actions". The first part of the parameter indicates the number of times the communications software checks for and executes pending send message actions for every second parameter part number of receive message actions taken.
The communications software uses this parameter to configure the frequency of send versus receive actions. Note that MRN information will generally be the only positive acknowledgment received when "None" level acknowledgment is requested for the message. When the communications software sends a message over the network requesting "Service" level acknowledgment, the LES provides a Positive Delivery Notification PDN to the DCE when it successfully delivers the message to the destination communications device.
Whenever the communications software receives the required response for a transmitted message i. Messages that have been successfully transmitted do not need to be saved at communications software termination.
The communications software interfaces with the DCE and accepts data streams received by the communications device. The communications software monitors the incoming data and if the message begins with a data sequence that matches the Format Indicator, the communications software identifies the incoming data stream as an MMS user message that it should receive. The communications software provides this MRN to the application with the user message.
This MRN is included with the message sent to the application; it is not included in a separate Message Status Local Message as in the transmitted message case. No matter what communications device is used, the application software constructs the DCE command, configuration, and query character strings defined for the device to send to the DCE.
The DCE responds to these commands and queries with response strings. Whenever the communications software receives command or query responses from the DCE, it sends the binary representation of the string received to the Application Software in a Comm Status Local Message. The communications software also receives DCE Event messages from the communications equipment and provides them to the application software in Comm Status Local Messages.
Again, the communications software provides the binary representation of the string received from the DCE in the local message. The communications software defined herein provides communications services to a "terrestrial end-system". The terrestrial end-system includes a Computer Aided Dispatch CAD system which requires access to the MMS network in order to communicate with the customer's mobile units.
Likewise, incoming messages and status information is given to the CPG application software where it is reformatted and translated into inputs to the CAD application.
This setup isolates the CAD system from any changes due to the implementation of communications software changes. Instead, the CPG application software absorbs the changes.
In customer systems where no CPG is used but, instead, the CAD application communicates with the communications software directly, any changes to communications software interface must be accommodated by chances to the CAD software. From the communications software standpoint, it is interfacing with a generic "terrestrial end-system".
On the terrestrial side of the MMS system, the communications software is responsible for opening and maintaining connections with the LES and exchanging data via those connections. There are several methods of connecting to and communicating with the LES which the communications software will support. The "device" and "physical" layers of the communications software provide the services to communicate with the LES using the required protocol and access method. The following functions are performed by the communications software in general to exchange data between customer applications and the LES.
Configuration parameters are used to set up the specifics required for the communications software to affectively utilize the lower-layer device dependent communications protocols.
The communications software is responsible for establishing connections with the network and maintaining them. The communications software performs several transactions with the LES at the same time. To manage these potentially simultaneous transactions, the communications software maintains "virtual circuits" with the LES on which the transactions are performed.
Whenever a transaction is needed, the communications software finds an available circuit or establishes a new one. Since the LES times-out a connection after a period of inactivity or closes a connection after a certain number of transactions, the communications software maintains these circuits and monitors which ones are available.
If the communications software needs to perform a transaction when no circuits are open and no more are allowed due to a maximum number of open circuits constraint , the communications software holds the transaction until a circuit is available or one can be opened. There are two customer message reception modes supported by the LES. If the customer is set up for "store and forward", the LES stores all incoming messages until the LES connects and forwards the data to the customer's X.
The communications software supports this mode by listening for connection requests from the LES and performing the necessary handshaking required to establish the LES connection and to receive the data being forwarded.
These LES initiated connections do not count in the number of virtual circuits being maintained as described above. The communications software supports requesting and retrieving these DNID files. In order to access the LES, the communications software first configures its communications over the host computer's communications port the port used depends on the LES access method.
The communications software configures the port's communications settings. The communications software is also responsible for monitoring the health of the network and for insulating the terrestrial end systems from any adverse affects that may result from network degradation. The communications software checks the network's health at a predetermined interval. If the LES access method is "Dialup", these network health checks consists of checking the status of accessing the Comm port and the health of the modem.
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