WO1997040640A1

WO1997040640A1 - Inbound overlay system to an outbound paging system

Info

Publication number: WO1997040640A1
Application number: PCT/US1997/006230
Authority: WO
Inventors: Steven Jeffrey Goldberg; Gene Steven Gurley; Michael P. O'brien
Original assignee: Motorola Inc.
Priority date: 1996-04-25
Filing date: 1997-04-11
Publication date: 1997-10-30

Abstract

A two-way messaging system using an inbound overlay system (50) to an outbound paging system (10) having a user access terminal (12) with a subscriber list, a controller (14), and a base station transmitter (16), the inbound overlay comprises a plurality of subscriber units (56), each of the plurality of subscriber units being capable of receiving and decoding outbound selective call messages from a base station transmitter and for transmitting inbound signals (57), a plurality of overlay base receivers (54) wherein at least one of the plurality of overlay base receivers receives and decodes the inbound signals from the subscriber unit to provide inbound decoded information, and an overlay user access terminal (52) for managing and correlating the inbound decoded information with the subscriber list.

Description

INBOUND OVERLAY SYSTEM TO AN OUTBOUND PAGING

SYSTEM

Technical Field

This invention relates generally to a paging system, and in particular, to a two-way messaging system using a inbound overlay system with an outbound paging system.

Background

Two-way asymmetrical messaging has benefits in certain communication scenarios. These scenarios are generally characterized by the ability to move data in non real-time and by outbound data greatly exceeding that of inbound data. The benefits include the ability to pack data more efficiently since the delivery can be delayed and provided in any sequence, thus increasing channel utilization; and power savings in the respect that a subscriber unit would only have to wake up at known widely separated times and that lower inbound data rates and short transmissions mean the power required is considerably less than for full duplex operation.

One type of service that could benefit from a two-way system is campus type systems which may require inbound capabilities, but can revert to a one-way system external to the campus. For example, a hospital campus would find it very desirable to know who can respond to a page located on the grounds.

These reasons make two way asymmetrical messaging systems attractive and explain why they are being adopted and implemented by many service providers. The cost to implement these systems with new infrastructure equipment can be a barrier to entry for some into the market place. Thus, a need exists for a lower cost solution that could take advantage of existing one-way infrastructure to provide a two-way asymmetrical messaging system. Additionally, a need exists for a means to cost effectively deploy an inbound message capability in a campus environment, while taking advantage of the inexpensive area wide coverage of a public paging system.

Summary of the Invention

In a first aspect of the present invention, a two-way messaging system using an inbound overlay system to an outbound paging system having a user access terminal with a subscriber list, a controller, and a base station transmitter, the inbound overlay comprises a plurality of subscriber units, each of the plurality of subscriber units being capable of receiving and decoding outbound selective call messages from a base station transmitter and for transmitting inbound signals, a plurality of overlay base receivers wherein at least one of the plurality of overlay base receivers receives and decodes the inbound signals from the subscriber unit to provide inbound decoded information, and an overlay user access terminal for managing and correlating the inbound decoded information with the subscriber list.

In a second aspect of the present invention, an overlay user access terminal for managing and correlating inbound decoded information from a two-way subscriber unit with a subscriber list from an one-way paging system, comprises a plurality of inputs for receiving decoded acknowledgment signals from at least one of plurality of two-way subscriber units, a memory containing a subscriber data base, and a processor for correlating and managing the subscriber list from the one-way paging system with the subscriber data base in the memory of the overlay user access terminal.

In a third aspect of the present invention, a method of overlaying an inbound paging system to a one-way outbound paging system having a subscriber list comprises the steps of providing a plurality of subscriber units, wherein at least one of the plurality subscriber units is a two-way subscriber unit capable of transmitting an acknowledgment signal. Then, receiving the acknowledgment signal at one or more of a plurality of overlay base receivers. The next step is to decode the acknowledgment signal at the one or more of the plurality of overlay base receivers to provide an inbound decoded signal. Then the inbound decoded signal is received at an overlay user access terminal. Finally, the inbound decoded signal is correlated with the subscriber list of the one-way outbound paging system at the overlay user access terminal.

Brief Description of the Drawings

FIG. 1 is a block diagram of a two-way asymmetrical messaging system using an inbound overlay paging system in accordance with the present invention.

FIG. 2 is another block diagram of a two-way asymmetrical messaging system using an inbound overlay paging system in accordance with the present invention.

Detailed Description of the Preferred Embodiment

The present invention utilizes existing outbound paging infrastructure and adds the function of an inbound channel as an overlay, thus greatly reducing the initial outlay in infrastructure costs to an existing one-way paging service provider. Fundamentally, the vast majority of two way uses can be implemented by generating appropriate blind one way traffic that in no way requires additional equipment for a traditional outbound carrier. Referring to FIG. 1 , a block diagram for the overlay system is shown in accordance with the present invention. The elements above the demarcation line 100 can be found in an existing outbound only paging system 10. The elements below the line 100 belong to the inbound overlay system 50. The outbound only paging system typically comprises a user interface 11 which can simply be a conventional phone or preferably an alphanumeric entry device such as Motorola's Alphamate® alpha entry device or a computer having software allowing for a modem or an internet connection to a paging terminal such as the user access terminal 12. Messages and data received at the user access terminal 12 are preferably forwarded via link 13 and encoded, queued and batched at a controller 14. Alternatively, these functions or portions of these functions can be done in separate units or within a paging terminal such as the user access terminal 12. Additionally, the controller can receive data or messages from other sources (21 and 23). Once the functions of queuing and batching are done, the messages can be forwarded to one or more base station transmitters (16) over a plurality of links (15, 25 and/or 27). The base station transmitter 16 can then transmit a selective call message over an RF outbound path 17 to a plurality of subscriber units (18 and 56). The subscriber unit 18 can be a typical one way unit and the subscriber unit 56 is preferably a two way unit such as Motorola's Tango™ two-way personal messaging unit.

The subscriber unit 56 preferably has receive and transmit capabilities and preferably its operation will differ from existing two way systems in what it expects to receive from the one way only infrastructure, and the different means for delivering two way control data. In other words, the formatting, location, and vehicles used to route control data found in an existing one-way outbound system could be changed so that the overlay system is accommodated without affecting the existing one-way system. For instance, control data typically only found in a header can be imbedded in the message portion of an outbound paging transmission. In any event, the subscriber unit 56 preferably uses an RF inbound link 57 to transmit to an infrastructure receiver 54 or a plurality of infrastructure receivers (not shown). The subscriber unit 56 can use a variety of modulation techniques for transmitting its inbound signals (i.e., acknowledgment signals, canned responses) including spread spectrum techniques. This receiver 54 may be the same as those used in non-overlay two way messaging systems and should be able to decode the modulation technique used by the subscriber unit, but they need not be aware of whether this is an overlay or a complete two way system. The Infrastructure receiver 54 is preferably linked to an overlay user access terminal 52 which will provide reconciliation of inbound and outbound messages among other things. Optionally, the infrastructure receiver 54 could have two receivers within the same unit to decode both the inbound messages from the subscriber unit as well as the outbound messages coming from one-way outbound paging system 10. Alternatively or in addition to the infrastructure receiver 54, a separate infrastructure receiver 69 could be used as a monitor receiver for directly receiving and decoding outbound messages to further add to the integrity of the inbound overlay system. Thus, inbound messages from the subscriber unit 56 will be correctly correlated with the outbound messages from the paging system 10. The infrastructure receivers that directly receive and decode the outbound messages from the paging system 10 are particularly useful in cases where the messages did not originate from the overlay user access terminal 52 or the inbound overlay system, but from the user interface 11 for instance.

Another option than could eliminate the costs of additional user interfaces and associated phone lines comprises the coding and re-routing of messages designated for the two-way system. For instance, a message that is designated for a known two-way subscriber unit that is initiated through the user interface 11 of the one-way outbound paging system, could be redirected at the user access terminal 12 to be sent to the overlay user access terminal 52 via link 65. This would allow the overlay user access terminal to act as if the message was initiated at the user interface 58 without requiring the user interface 58. Then, the message could be sent back through link 65 to the user access terminal 12 with the subscriber identification modified such that it is recognized as an outbound only subscriber unit, or the message could be sent directly to the controller 14 from the overlay user access terminal 52 via link 67. Again, the controller 14 in this instance should view and handle the information from the overlay user access terminal 52 as if the message was initiated from the user access terminal 12 and intended for a typical one-way subscriber unit.

Callers accessing two way devices such as subscriber unit 56 can reach the overlay user access terminal 52 via a plurality of RF inbound links (53, 59, 61). Alternatively, like the one way user access terminal 12, another user interface 58 such as a computer with alpha entry paging software can be linked to the overlay user access terminal 52. The user interface 58 could be used among other things to modify subscriber lists, modify class of service for a particular subscriber, or initiate a page through the overlay user access terminal 52. Initiating an outbound page through the overlay user access terminal 52 would require either a link 65 to the one way user access terminal 12 or a link 67 to the controller 14 of the outbound paging system. The link used would depend on the configuration of the service provider's system. The overlay user access terminal 52 is cognizant of the two way operations and would have access to a data base in memory 55 (or elsewhere) necessary to properly signal the subscriber units. Signals received from the subscriber units are processed and acted on accordingly. Additionally, a two-way system, including this overlay system can allow for roaming of subscriber units among different paging systems. Thus, an intraterminal link 60 coupled to the overlay user access terminal 52 as well as to a remote terminal 62 from another system would facilitate the forwarding of messages and location finding of roaming subscriber units. The remote terminal 62 can also be another overlay user access terminal like terminal 52.

The means for interconnecting the various blocks are numerous. In general they will be driven by the service provider's existing data networks, the availability within the regions of service, and the costs of the available means. Co-location of the parts, although often a cost advantage, is not necessary to the effective operation as long as the latencies are not severe and the bandwidth adequate for existing traffic.

The present invention allows to a varying degree for several full two- way features using inbound control via the outbound infrastructure. For instance, frequency reuse is a feature that creates the ability to locate a subscriber unit to a sufficiently restricted area so a limited number of transmitters can be used for further delivery of data. Other subscriber units which are sufficiently separated from the unit can then also use the same communication resource (same frequency or time slot, etc.) without there being harmful interference at each subscriber unit location.

Regional systems have no RF coverage overlap. If a subscriber unit is isolated to a single region, reuse can therefore occur in other regions. Each region may still have its data broadcast in simulcast. The overlay system of the present invention will always be able to provide this level of resolution.

In overlap regions the difficulty is identifying a subset of overlapping transmitter patterns. Using just receiver information may not be viable for single transmitter identification. A set of transmitters would therefore be identified. If the region was sufficiently large, it may therefore be possible to identify non-interfering simulcast sub-regions for bulk data delivery. For example, a system simulcasting from Boston to New York, could identify units in Boston and New York, and simulcast different data around those two cities without worrying about interference occurring in Connecticut.

Full two way systems can work around this problem by having each transmitter send out a unique identification code. These codes returned by the subscriber unit to the infrastructure allow the identification of one or a few transmitters that are capable of reaching the unit. By simply updating the existing one-way base stations to provide these codes, this capability could also be added to the overlay system's capabilities.

A two-way system allows you to eliminate unnecessary transmissions. If the message body is large compared to the size of a minimum page, it is often beneficial to first determine if the pager will be able to receive the bulk transmission. A simple "are you there" page with the appropriate response from the subscriber can therefore be sent to determine if the subscriber is even available to receive such lengthy messages. Taking one step further, a page requesting acknowledgment and the memory available at the subscriber can further aide in reducing unnecessary transmissions.

On the other hand, a two-way system has the capability to retransmit messages to improve reliability. The two-way system can use a time out period based on the lack of receipt of an expected inbound response in response to an outbound page which does not acknowledge receipt. Thus, the message can be resubmitted to the outbound paging system to increase reliability.

As a unit moves to different regions it searches for regional identification codes. These could exist in the normal protocols, or be generated as periodic global pages by the overlay terminal. When a unit detects it has entered a different region, it transmits an unsolicited message. The system receiving this message informs the home system of the unit as to its whereabouts. The home system will now only send pages to the registration area. If the page is not acknowledged in the registration area and if the customers options are set appropriately, the system may hunt for the unit in other regions, having assumed that registration failed for some reason.

A two-way system facilitates the delivery of subscriber originated information or replies to outbound requests. The delivery of responses, delivery confirmation or failure, or read indication can be delivered by outdialing, holding the information for caller inquire, forwarding to another pager, or a variety of other means.

The inbound overlay system essentially uses a subscriber unit (56) and infrastructure adjunct (52 &54) to exploit the existence of outbound only paging systems without them being aware or modified. In this way, additional paging traffic is generated to an existing outbound only paging system to do among other things, retransmit an undelivered page, or locate a subscriber unit's position, or retransmit uncorrupted or unacceptable data previously sent, or to manage the inbound traffic in a more efficient manner than present art allows. Additionally, the overlay system allows for input and return of two way traffic via the overlay portion of the system.

Many of the benefits described above are equally applicable to the inbound overlay system 501 of FIG. 2. The elements above the demarcation line 100 once again can be found in an existing outbound only paging system 10 as described with FIG. 1. Likewise, the elements below demarcation line 100 belong to the inbound overlay system 501 , which preferably comprises all the same elements described with respect to the inbound overlay system 50 of FIG. 1 in addition to other elements to be described. The overlay user access terminal 52 of FIG. 2 could be a computer dedicated to the purpose of a terminal or a computer with an application running as a background task. Its basic purpose is to reconcile the inbound response traffic with the outbound paging traffic. In this case, the overlay user access terminal 52 acts as a control point or as an Intelligent Network Adjunct to a Private Branch Exchange (PBX) system of a local campus style system. It can process a page request, and store the information pertinent to the expected responses from subscriber units. The pages are then sent to a wide area paging system via a network interface. As seen in FIG. 2, this can be achieved in many ways. Responses and requests from a subscriber unit 56 can be received by an infrastructure receiver 54 as described in FIG. 1 or a receiver coupled to a computer 72 via RF link 57. Responses or requests could also be received by a transceiver coupled to a computer 70. The computer 72 would be linked to the overlay user access terminal 52 via link 59 to reconcile against expected messages. If the computer 72 or computer 70 is not directly coupled to the overlay user access terminal, then the computers (70 or 72) can indirectly forward responses or requests to the overlay user access terminal 52 via a local area network 74. The overlay user access terminal 52 can then forward requests to initiate a page via link 67 to the controller 14 of the outbound paging system. Alternatively, the local area network 74 can be used to forward requests to either the user access terminal 12 or controller 14 of the outbound paging system via a network gateway 75 and a wide area network 76 as shown. Use of the network gateway 75 and wide area network 76 depend upon the particular configuration of the campus computer network and the configuration of the outbound paging service provider. Finally, a local transmitter coupled to a computer 71 could be used within a computer network to transmit local content information to the two-way subscriber unit 56.

Preferably the information sent to the subscriber unit contains some possible actions, and the target for the response. The response and target are sent inbound by the subscriber unit 56, and the controller or overlay user access terminal 52 interprets what should be done with it. Both the inbound and outbound traffic are captured. The controller 14 therefore acts on the inbound, based on its decode of the outbound forwarded to it by the overlay system. Regeneration of pages that were not received or received inappropriate responses would be a basic use of such an implementation.

Ideally, the system of the present invention would provide for forwarding for two-way usage. In other words, a wide area network could be given knowledge of the two-way overlay. It would then forward either the page request, or an action option list to the local controller when a suitable page request was received. The local controller would then have the same capabilities as if the input occurred locally.

While the receivers in a local campus style system could use a private link network for their communications, the use of existing computer networks would provide for great cost savings. Computer networks have become ubiquitous in the manufacturing and business buildings of technologically advanced countries. The most predominant of these networks use the protocols referred to mnemonically as TCP/IP. TCP being the Transport Control Protocol (concerned with data integrity and movement), and IP which is the Internet Protocol (concerned with unique addresses of entities). The present invention preferably proposes the construction of two ported communication devices. One of the ports preferably consists of a slot for a particular portable communications device type such as a PCMCIA or PCIA receiver device. The other port connects to existing computers or servers by a standard interface such as an RS232 or RS423 or other suitable interface. This interface should be a very generic form suitable for connection to the vast majority of existing computer on a network. If a particular network is made up of numerous computers of the same type, a more cost effective implementation would be cards which directly plug into a computer's bus structure. This eliminates the need for additional power supplies, cabling, cases and so on. An implementation using a PCMCIA or PCIA form factor receiver or transceiver would be preferable. While not all fixed computers support this type of physical device, it is generic across computer types. A further variation would involve the slight remoting of the receivers from these ported computers serving as gateways to a computer network. This is desirable to extend the range of the portable devices. This could be accomplished by cables, infrared, or RF links. The long distance links would remain the existing local area network.

However the port is attached to the computers, a computer program is required on the host computer. This program would perform the task of communicating between the network gateway and the computer's communication network such as the local area network 74. The communication occurs transparent to the user of the computer. Ideally the computer's user would be ignorant of the network gateway transactions being performed. This is really dependent upon the capabilities of the computer.

Ethernet is the most widely deployed computer oriented communications hardware layer. The present invention would most likely be initially utilized with Ethernet as the communication backbone. The two port gateways which plug into or attach to the computers would in general be ignorant of the actual backbone used. Other possibilities would be variations on the IEEE specifications set 802 (Ethernet being 802.3), wireless WANs, Appletalk Network, ATM, or other suitable specifications.

The use of TCP as the transport protocol is likewise the predominant transport layer protocol, and therefore targeted for compliance. Other protocols such as UDP could be used under appropriate circumstances.

If all networks were ideal from the standpoint of bandwidth and delay, the invention could be deployed on a global basis. The existing (1996) networks however will limit its usefulness usually to building or campus deployments. In these locally controlled environments, the variations of the system are to some degree under the control of the local management. If a problem occurs, it is possible for the local management to do something about it. Public networks however are subject to more variations, and unforeseen loading and system characteristic changes. All this could possibly change in the future. The concept of information superhighways when deployed, would theoretically provide sufficient excess capabilities to allow this invention's wider deployment. Examples of this are existing service providers who loop high capacity fiber networks around a city. As the number of these loops expand and the interconnections between them proliferate, an implementation using the present invention can likewise expand and proliferate.

What is claimed is:

Claims

1. A two-way messaging system using an inbound overlay system to an outbound paging system having a user access terminal with a subscriber list, a controller, and a base station transmitter, the inbound overlay system comprising: a plurality of subscriber units, each of the plurality of subscriber units being capable of receiving and decoding outbound selective call messages from a base station transmitter and for transmitting inbound signals; a plurality of overlay base receivers wherein at least one of the plurality of overlay base receivers receives and decodes the inbound signals from at least one of the plurality of subscriber units to provide inbound decoded information; and an overlay user access terminal for managing and correlating the inbound decoded information with the outbound selective call messages.

2. The two-way messaging system of claim 1 , wherein the inbound signal is a spread spectrum signal.

3. The two-way messaging system of claim 1 , wherein the overlay user access terminal is coupled to the controller of the outbound paging system.

4. The two-way messaging system of claim 1 , wherein the overlay user access terminal is coupled to the user access terminal of the outbound paging system.

5. The two-way messaging system of claim 1 , wherein the overlay user access terminal is coupled to the user access terminal and the controller of the outbound paging system.

6. An overlay user access terminal for managing and correlating inbound decoded information from a two-way subscriber unit with a subscriber list from an one-way paging system, comprising: a plurality of inputs for receiving decoded acknowledgment signals from at least one of plurality of two-way subscriber units; a memory containing a subscriber data base; and a processor for correlating and managing the subscriber list from the one-way paging system with the subscriber data base in the memory of the overlay user access terminal.

7. The overlay user access terminal of claim 6, wherein the overlay user access terminal is coupled to a controller of the one-way paging system.

8. The overlay user access terminal of claim 6, wherein the overlay user access terminal further comprises a user interface for sending messages and receiving acknowledgments.

9. An inbound overlay paging system using a plurality of networked computers used in conjunction with an outbound paging system, comprising: a subscriber unit for receiving messages from the outbound paging system and for transmitting messages to the inbound overlay paging system; at least one receiver coupled to one of the plurality of networked computers for receiving the messages from the subscriber unit; and an overlay user access terminal coupled to the plurality of networked computers for managing and correlating the inbound messages with a subscriber list.

10. The inbound overlay paging system of claim 9, wherein the system further comprises at least one transceiver coupled to one of the plurality of networked computers for transmitting and receiving localized messages to and from the subscriber unit.