WO1996027952A1

WO1996027952A1 - Dual channel fm receiver with on demand information services

Info

Publication number: WO1996027952A1
Application number: PCT/US1996/002757
Authority: WO
Inventors: Dimitri Dimitriadis
Original assignee: Seiko Communications Systems, Inc.
Priority date: 1995-03-08
Filing date: 1996-02-29
Publication date: 1996-09-12
Also published as: JPH11505683A; EP0813772A1; CA2214716A1; AU4997896A

Abstract

Information services on demand by user allows a user in a one-way communication paging system to obtain on a limited basis information service items without interacting directly with the paging system to demand transmission thereof. The system provides information services in separate transmission channels. In each transmission channel including information service items, indicia thereinindicates categories of information items available therein. A remote information terminal (106), in response to user demand for a given category of information service (306), seeks information service items in that category by monitoring transmission channels and comparing information service indicia therein to the demanded information service. The user need not interact directly with the paging system to obtain information service items on a limited basis.

Description

DUAL CHANNEL FM RECEIVER WITH ON DEMAND INFORMATION SERVICES

RELATED APPLICATIONS The present application is a continuation-in-part of U.S. Patent Application

Number 08/365,859 filed December 29, 1994 naming inventors John Richartz and Dimitri Dimitriadis and entitled TRANSMITTING AND DISPLAYING ON A RECEIVER INFORMATION DESCRIBING BROADCAST PROGRAMS; and a continuation-in-part of U.S. Patent Application Serial Number 08/366,208 filed

December 29, 1994 naming inventors John Richartz and Dimitri Dimitriadis and

entitled SYSTEM FOR IDENTIFYING AND RESPONDING TO DIFFERENT BROADCAST PROGRAMS. Both of the above U.S. Patent Applications are assigned in common to the Assignee of the present application.

FIELD OF THE INVENTION

The present invention relates generally to communication systems, and particularly to delivery of information services on demand to a remote personal information terminal.

BACKGROUND OF THE INVENTION Commercial FM (frequency modulation) radio stations can simultaneously transmit both a main audio signal and a subcarrier signal. The main audio signal carries the traditional voice and music presentation and the subcarrier signal can carry for example a data signal for a paging system. Normal FM radios receive the main signal and paging devices such as the devices shown in U.S. Patent Number 4,713,808 entitled WATCH PAGER SYSTEM AND COMMUNICATION PROTOCOL and issued December 15, 1987, receive paging messages transmitted on the subcarrier.

Information service delivery to users of personal information terminals can

take a variety of forms. One type of information delivery system is by radio signal broadcast to remote radio signal receiving devices. The communication link is a one-way link, there being no radio signal transmission capability in the remote personal information terminal.

Information service delivery has been incorporated into existing paging systems. Users of the paging system devices subscribe to information services as represented in a subscription arrangement previously established and maintained by the paging system. Such information subscription arrangements are established by the paging system operator causing certain information service paging messages to be directed to a given paging device.

A user sometimes wants to only obtain a certain information service item

once or a limited number of times when needed. For example, when a travelling user of a receiving device leaves a "home" region or city and goes to another area. While in the distant area and away from home, the user has different information service requirements. Furthermore, signal transmission in the distant area does not

correspond to signal transmission in the home region, i.e., a different frequency or set of frequencies carry information addressed to receiving devices normally located in that distant area. To obtain information services while away from home, the user could contact the paging system operator to direct certain information services to its

terminal while in the distant region. Upon leaving the distant region, however, the user must again contact the paging system to modify its subscription.

Incorporating information services into a paging system can consume a significant portion of the system bandwidth. For example, some information services

require transmission of a significant volume of data, e.g., stock information. In some multiple-frequency paging systems, i.e., systems employing a plurality of transmission facilities to provide paging messages to frequency-agile receivers, all information services are provided on all transmission frequencies. Redundancy in

paging system transmission better ensures reception of vital information, i.e., paging information, by paging devices. Since some information services consume significant information delivery bandwidth. It is not feasible to incorporate a broad

spectrum of information services into a paging system.

Accordingly, it would be desirable to provide in a one-way communication system, e.g., in a paging system, an ability to provide on demand information services without requiring the user to interact with the paging system by way of an alternate channel of communication, e.g., by telephoning the paging system to modify information service paging messages directed thereto. The user would like

to access on a limited basis, i.e., one or several times, information service items without inconvenience and without establishing an information service subscription through interaction with the paging system.

The subject matter of the present invention provides information services on demand by user whereby the user need not interact directly by alternate communication channel with the paging system to receive selected information

service items on a limited basis.

SUMMARY OF THE INVENTION The present invention provides in an information delivery system a receiver receiving both a main FM station audio transmission and a subcarrier transmission. In addition to normal paging messages, the receiver receives information services on user demand by way of the subcarrier signal. The user selectively receives one or both of an audio signal and paging system data including information services on

demand.

A method of information service delivery under the present invention includes reception of a set of information service items in a plurality of information categories. A first subset of information service items are broadcast in a first transmission channel and a second subset of information service items are broadcast in a second

transmission channel. Each transmission channel providing information service items also includes indicia of information category found therein. Remote information terminals respond to a user demand for a given information category by seeking indicia corresponding to the demanded information category in at least one of the first and second transmission channels.

A system delivering information services to remote information terminals under the present invention includes a radio signal transmission portion providing

data transmission across a plurality of transmission channels. A transmission control portion receives information items in a plurality of information service categories and broadcasts such information items by way of the radio signal transmission portion in at least two of the transmission channels. Each radio signal

transmission includes indicia therein corresponding to at least one information category available therein. At least one of the remote information terminals includes a user-interface allowing a user to demand information in a selected information service category. The terminal then seeks to user demanded information service

items in the selected category by monitoring at least one of the radio signal transmissions and comparing information service category indicia therein to the demanded information category.

The subject matter of the present invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. However, both the organization and method of operation of the invention, together with further advantages and objects thereof, may best be understood by reference to the following description taken with the accompanying drawings wherein like reference characters refer to like elements. BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which:

FIG. 1 illustrates a personal information terminal receiving both conventional audio radio signal and data signal transmissions from FM radio stations.

FIG. 2 illustrates in block diagram the personal information terminal of FIG. 1.

FIG. 3 illustrates generally information services on demand by user system encompassing three distinct geographic areas.

FIG. 4 illustrates in more detail signal transmission facilities of the system of FIG. 3.

FIG. 5 illustrates a data packet transmission protocol employing multiple frequency transmission wherein each transmission references similar but relatively offset time frames in a time-division multiplexed transmission protocol.

FIG. 6 illustrates a second form of a personal information terminal receiving selected information service items on user demand in accordance with the present

invention. FIG. 7 illustrates generally programming in the paging system receiving information service data and distributing subsets of information service data among

transmission channels.

FIG. 8 illustrates programming for information terminals showing normal paging message reception and also showing information service reception

according to user demand.

FIG. 9 illustrates personal information terminal programming further detailing on demand information service reception in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates a personal information terminal 106 operating in accordance with the present invention. FIG. 2 illustrates terminal 106 in block diagram. Generally, terminal 106 is a combined audio and data FM radio signal receiving device. With reference to FIG. 1, each terminal 106 includes a liquid crystal display (LCD) 301 for presentation of FM radio tuning information and, as explained more fully hereafter, and a LCD 300 for presentation of paging messages and information sen/ices provided on demand in accordance with the present invention. Terminal 106 includes an AM/FM switch 180 as well as a volume dial 182 and tuner dial 184 to receive and present to the user a conventional audio signal.

In FIG. 2, each terminal 106 includes an antenna 186 coupled to receivers 188a and 188b. Receivers 188a and 188b produce baseband composite signals 190a and 190b applied to bandpass filters 191 and 192, respectively. Bandpass filter 199 monitors a subcarrier signal for application to a data decoder 193. Bandpass filter 192 extracts a main audio channel for application to a stereo decoder 194. Stereo decoder 194 applies right and left audio channels to a stereo amplifier 195, which in turn drives right and left speakers 196 according to volume control 182. Data decoder 193 drives a data presentation and storage block 197.

Each of receivers 188a and 188b may be selectively tuned to a given broadcast frequency whereby a selected main audio signal and selected data transmission are received concurrently from one or more FM radio stations. A single frequency agile receiver may be employed to receive audio signal transmissions, but during brief, e.g., 35 millisecond, intervals receive paging message data packets on the same or a different broadcast frequency. While such

brief loss of the audio signal would possibly be audible to the user, the audio signal would be generally comprehensible. The present embodiment, however, will be shown with two separate receivers 188a and 188b, each individually tunable to a selected FM station to receive audio and data transmissions, respectively.

A programmable controller 170 orchestrates generally operation of terminal 106 including monitoring buttons 302, 304, and 306 and FM radio controls 180 and 184. Controller 170 activates and tunes receivers 188a and 188b and dictates operation of data presentation and storage block 197 and of data decoder 193. Thus, each terminal 106 monitors both selected audio and selected data

transmissions. FIG. 3 illustrates generally an information service on demand by user system encompassing three distinct geographic areas 100a, 100b, and 100c, in the

illustrated embodiment city A, city B, and city C, respectively. Each city or area 100 includes a plurality of radio signal transmission stations 102 each broadcasting, at separate frequencies and according to a given transmission protocol, a broadcast signal 104 to a plurality of personal information terminals (T) 106. Users of personal information terminals 106 travel within a given city or area 100, or may travel

between areas 100.

Each personal information terminal 106 is a frequency-agile device capable of tuning to selected frequencies, and thereby receiving information from a selected one of stations 102, e.g., data and audio signals taken from different stations 102. Data transmission and reception within the information services system of FIG. 3 operates according to a given broadcast protocol. For example, the illustrated system operates generally in the fashion of a paging system, or incorporated within a paging system protocol. The present invention will be illustrated with reference to a particular paging system protocol, but the invention is not limited to the particular paging system and transmission protocol selected herein for illustration of the present invention.

The present invention will be described in the context of a paging system as disclosed in U.S. Patent Number 4,897,835 entitled HIGH CAPACITY PROTOCOL WITH MULTISTATION CAPABILITY and issued January 30, 1990. In U.S. Patent Number 4,897,835, a wide area paging system is disclosed in which paging messages input to the system in one local area can be broadcast to a receiver in any other local area without necessarily broadcasting the message in all areas. A

local area clearinghouse in each area stores resident subscriber data including current location and receiver serial number. This data is used to transfer messages over a data network to the correct clearinghouse. The system uses a TDM data

protocol. The data is encoded and transmitted at a very high rate (e.g., 19,000 baud) in short packets (256 bits/13 milliseconds) via stereo FM sidebands. Receivers are assigned to receive sequentially numbered time slots matching a portion of their address. The addresses of intended receivers are included in the

data packets. Receivers can be deactivated between packets and reactivated in accordance with the sequential time slot number scheme to receive an incoming packet. Messages longer than a packet are segmented and transmitted in two or more packets, linked together by data contained in the packets. A watch pager used in the system employs a wristband antenna which electromagnetically couples to the user's body. The watch pager displays time, telephone numbers and icons

representing common types of paging messages.

FIG. 4 illustrates generally the transmission stations 102 of FIG. 3 as well as delivery of information to stations 102 and coordinated information delivery among the regions 100. In FIG. 4, a plurality of stations 102, each providing a separate broadcast signal 104, each include a subcarrier generator 120. Subcarrier generators 120 receive a data stream 122 from a paging system clearinghouse 124. Subcarrier generators 120 produce a subcarrier signal incorporated into the normal audio signal transmission, e.g., an FM signal transmission provided by a commercial

FM radio station comprising one of stations 102. Paging system clearinghouse 124

orchestrates delivery of paging data streams 122 to stations 102 according to

paging system protocol. Such protocol includes not only formatting and addressing

of paging information for reception by selected information terminals 106, but also

relative offset in paging data signal transmission among the stations 102.

Clearinghouse 124 interacts through a public switch telephone network (PSTN) 126

with a plurality of telephones 128, represented by a single telephone 128 in FIG. 4.

Telephones 128 allow callers to submit paging messages to clearinghouse 124 for

delivery to selected information terminals 106. Further, users of terminals 106

employ telephones 128 to interact with paging system clearinghouse 124 when

necessary.

Clearinghouse 124 also receives by way of telephone network 126

information service items originating from information sources 130. Information

sources 130 submit information in a variety of categories to clearinghouse 124. In

this manner, the paging system makes available information services in distinct

categories to users of terminals 106. Clearinghouse 124 further includes an

intercity link 132 coupling clearinghouse 124 in a given area 100 with a

corresponding clearinghouse 124 in a separate area 100. In this manner, coordinated distribution of paging messages and information services results among

the areas 100a-100c. FIG. 5 illustrates generally the time-division multiplexed protocol dictating operation of stations 102 and personal information terminals 106. Each personal

information terminal 106 monitors a selected broadcast signal 104 during at least one time slot 200 of an associated cyclically repeating time frame 202. Each time frame 202 corresponds to one of stations 102, with a unique offset associated with

each station 102. Each time frame 202 includes a fixed number of time slots 200 each of fixed duration. Information terminals 106 interpret the leading three time slots, designated 200a, 200b, and 200c in FIG. 2, as control time slots. The remaining time slots 200 in each time frame 202 carry data packets directed to one or more members of the local population of personal information terminals 106.

Personal information terminals 106 tune to a selected station 102 and synchronize relative to the time frame 202 associated with that station 102. Each

terminal 106 stores therein a station list representing a set of stations 102 available in a given area 100. By reference to the station list, an information terminal obtains frequency values and relative time frame 202 offset values to selectively tune to stations 102 in a given area 100, and thereby selectively obtain paging data and information services from a given station 102 and time slot 200.

Data packets transmitted during the control time slots 200a, 200b, and 200c provide system information as discussed more fully hereafter. Each personal information terminal 106 is associated with at least one of the remaining time slots 200 in each time frame 202. More typically, however, each terminal 106 is associated with a set of time slots 200 within each time frame 202. Terminals 106 each have a unique serial or identification number a portion of this number provides a mask identifying a set of time slots 200 within each time frame 202. Each terminal 106 thereby identifies a set of time slots 200 assigned thereto. Each personal

information terminal 106 synchronizes operation relative to a selected station 102

and associated repeating time frame 202 to activate its radio signal receiving circuitry and receive data packets transmitted during a targeted time slot 200.

Each station 102 broadcasts message data packets with reference to one of repeating time frames 202, but time frames 202 are not in aligned synchronization. Time frames 202 are offset relative to one another. This relative offset allows a terminal 106 to switch frequencies, i.e., tune in a different station 102, and receive more quickly a data packet during its assigned time slot. The terminal 106 need not wait for the next assigned time slot in the original time frame 202. For example, if a given terminal 106 finds corrupted data in a data packet provided during its assigned time slot, it could wait until a next occurrence of an assigned time slot in the current time frame 202. Relative offset among time frames 202 allows a terminal

106 to switch stations 102 and more quickly encounter an assigned time slot 200. Radio stations 102 are, therefore, distinguished not only by distinct broadcast 104 frequencies of transmission, but also according to a given relative offset of each repeating time frame 202.

Each time frame 202 begins with control time slots 200a, 200b, and 200c. Data packets transmitted by a given station 102 during control time slots 200a-200c provide a variety of configuration and system information. Time slot 200a provides a data packet including a system flag 208. The system flag, in the illustrated example comprising a 20 bit sequence "11110001111000110010", identifies to the

terminal 106 the paging system source of information provided in the broadcast signal 104. Terminals 106 differentiate among one or more paging systems employing similar transmission protocol by reference to the system flag 208 leading each time frame 202. As will be discussed more fully hereafter, variation in the system flag available during control time slot 200a of each time frame 202 indicates a sub-system within a given information system. For example, sub-systems may be designated for carrying particular categories of information, i.e., particular

information services.

Data transmitted during control time slot 200b includes a variety of configuration information, including one or more information service codes 210. Each code 210 indicates an information service available in the associated broadcast signal 104. For example, a set of information codes designate one or more of the following information services: weather, basketball scores, football scores, hockey scores, Dow Jones index, transportation index, airline index, and mutual funds index. For each information service available, a corresponding unique

code is assigned.

Terminals 106 seek particular information services in response to user demand by monitoring stations 102 and receiving information service codes 210, and comparing received codes 210 to demanded codes 210. For example, a terminal 106 seeks basketball scores by sequentially tuning to stations 102, monitoring the information codes 210 broadcast during a time slot 200b, and, upon

finding a station 102 broadcasting basketball scores, receiving basketball scores during a particular time slot 200 of the associated time frame 202. Similarly, terminals 106 seek particular information services in response to user demand by monitoring broadcast 104 seeking a particular system flag 208, i.e., a system flag

208 associated with a given one or set of information services. Information terminals 106 need not have information subscription messages specifically directed thereto to receive selected information services. The terminals 106 respond to user demand by seeking information services according to the content of signal broadcasts 104, i.e., by looking for particular service codes or particular system flags.

Returning to FIG. 1, each terminal 106 includes a set of control buttons. Activation of time button 302 causes presentation of a current time and date on display 300. The user activates button 304 to display stored or just-received paging

messages at terminal 106. Information service demand buttons 306, in the illustrated embodiment individually designated 306a, 306b, 306c, and 306d, cause terminal 106 to deviate from normal operation and seek information reflected in a user information service demand initiated by user activation of one of buttons 306. As illustrated, buttons 306a-306d correspond to weather, stock, football, and basketball information services. Button 306 assignments, i.e., association with a particular information service category may be fixed as illustrated in FIG. 1 , or programmable according to a given design or product criteria. A user of a terminal 106 receives specific information services on demand without establishing such information through a prearranged subscription established by direct interaction with the paging system operator.

While the particular terminal 106 shown has only four information service

demand buttons 306, a variety of alternate button and user-interface configurations may be employed to implement user demand for or reference to any desired number of information categories.

For example, FIG. 6 illustrates a watch-form terminal 106'. In FIG. 6, an LCD

display 320 provides alphanumeric information in "scrolling" fashion, i.e., presents textual information of significant length by scrolling through the display 320. The watch-form terminal 106', being limited in physical size and number of user-interface buttons available, makes multiple use of buttons 322 and 324. More particularly, in a normal mode of operation, button 322, when activated by the user, causes presentation of time and date information on display 320 and button 324, when activated, causes presentation of paging messages on display 320. By entering an information services demand mode, however, the watch-form terminal 106' makes alternate use of buttons 322 and 324. For example, by pressing both buttons 322

and 324 concurrently terminal 106' enters an information services demand mode wherein button 322 sequentially presents information service categories on display 320. When the user displays a desired information service on display 320, the user activates button 324 to select or demand information in that category. The watch-form terminal 106' thereby allows the user to "scroll and select" among available information categories. Reference to a given information category causes the device to seek information within that category in accordance with the present invention.

The invention will be described with reference to the terminal 106 as shown in FIG. 1, but certain programming and operation described also applies to the watch-form terminal 106' wherein "scroll and select" operation of buttons 322 and

324 substitutes operation of buttons 306 in the terminal 106 of FIG. 1.

Each terminal 106 monitors user activation of buttons 306 and seeks information services by switching to one or more stations 102 and by seeking an

appropriate information service code 210 or switching sub-systems by seeking broadcast signals 104 bearing an appropriate system flag 208. Each device 106 seeks a selected information service code 210 or a system flag 208 to satisfy the user-requested demand for a given information service. Station 102 tuning under normal multiple-frequency broadcast systems supports improved signal reception by tuning to a better-received station 102. Station 102 selection under the present invention is not for correcting bad reception, but rather to seek certain information services on demand without use of an alternate channel of communication, i.e., without calling the paging system operator.

FIG. 7 illustrates generally processing within the paging system directed to reception of information service data and distribution among transmission channels. In FIG. 7, the paging system receives in block 400 information service data from a variety of information sources. In block 402, subsets of information service data are assigned to appropriate transmission channels. More particularly, some information services may be assigned to dedicated paging systems, i.e., systems bearing a system flag 208 indicating broadcast of information services generally or particular information services. Further, information service data may be assigned to

particular stations 102 within a given paging system. Thus, "transmission channel" as indicated in block 102 refers to paging subsystems dedicated at least in part to information service broadcast or to particular stations 102 dedicated in whole or in part to delivery of particular information services. Continuing to block 404, the

paging system broadcasts the information service data according to transmission channel assignment. In other words, information data is directed to an appropriate transmission channel. In block 404, such broadcast may be intermixed with normal paging broadcasts or directed to dedicated paging subsystems or dedicated stations 102.

In any case, information service transmissions bear appropriate system flags

208 and information service codes 210 indicating the content of the transmission, i.e., indicating the category of information service available in that transmission. Thus, the paging system receives a set of information services and directs subsets of information services received to specific transmission channels. In this manner, overall system bandwidth is maximized by placing information service data on dedicated transmission channels, thereby leaving relatively more transmission

bandwidth available for paging message delivery. FIG. 8 illustrates generally operation of an information terminal 106 receiving normal paging messages, including messages generated by callers submitting requests to the paging system clearinghouse 124 or information service

subscriptions as established by pre-arrangement with the paging system. In addition, FIG. 8 illustrates response by the information terminal 106 to user activation of buttons 306 in implementation of information services on demand by user.

In FIG. 8, terminal 106 begins scanning generally for a data transmission in

block 500. Upon finding a data transmission, decision block 502 determines whether a valid system flag 208 is present, i.e., the terminal 106 receives information during a control time slot 200a. If a valid system flag is not present, processing returns to block 500 for further scanning to detect data transmission. If a valid system flag is found in decision block 502, processing advances to block 504 where terminal 106 stores the system station list including frequency and relative

time frame 202 offset values. In block 506, terminal 106 tunes to a system station. Decision block 508 determines if the currently tuned system station 102 operates according to a valid offset and frequency. If not, processing returns to block 506 to tune to a next system station 102. If a valid frequency and offset are found in block 508, processing advances to block 510 where terminal 106 targets a next time slot 200 for the time frame 202 associated with the presently tuned station 102, i.e., targets its assigned next time slot 200 to activate and receive information directed to

that particular terminal 106. Continuing to block 512, terminal 106 sets an interrupt for the next targeted

time slot to receive, if present during that time slot 200, normal paging information

including information service subscriptions as established by pre-arrangement with

the paging system. In block 514, terminal 106 interrogates buttons 306 to determine user activation. If a user has activated one of buttons 306, processing branches to

block 516 where terminal 106 executes an information service demand procedure

(FIG. 9).

Processing eventually reaches block 518 where terminal 106 activates its

radio receiving circuitry and receives a data packet during the targeted time slot 200. Thus, block 518 represents normal message reception according to normal

paging system protocol, including reception of information services as established

by pre-arrangement. Following block 518, processing returns to block 510 where

terminal 106 targets a next time slot 200 according to system protocol. If terminal

106 loses contact with the presently tuned system station 102, processing returns to

block 506 where terminal 106 employs the system station list to select a next station

102 for reception of paging system information.

FIG. 9 illustrates programming of terminal 106 as represented in block 516 of

FIG. 8. In FIG. 9, an information service demand procedure receives as parameters

a system flag 208 and an information service code 210. Activation of one of buttons 306 indicates to terminal 106 both a valid system flag 208 and a valid service code

210 for the user demanded information service. In block 600, terminal 106 scans for a valid information service system flag 208, i.e., one corresponding to the system flag associated with the demanded information service. Decision block 602

determines if a valid information service flag 208 has been obtained. If not, processing returns to block 600 for continued scanning in pursuit of a valid information service system flag 208. When a valid information service flag 208 is obtained, processing advances to block 604 where terminal 106 obtains a system

station 102 list. In block 606, terminal 106 tunes to a system station 102 and, in decision block 608, determines if that station 102 provides a valid information

service code 210. In other words, targets the control time slot 200b of that station 102 and interrogates the information service codes 208 for a match with the demanded information service. If not, processing returns to block 606 where a next

system station 102 is tuned in pursuit of an appropriate information service code

210 therein. When a valid information service code 210 is obtained, processing advances to block 610 where terminal 106 targets an information service time slot 200 of the current time frame 202. In block 612, terminal 106 receives the demanded information service data for storage and presentation on display 300.

Thus, information services on demand by user has been shown and described. The user need not interact directly with a paging system to receive

specific information services on a limited basis. A travelling user, upon entering a new area 100 and activating one of buttons 306, indicates to terminal 106 a desired information service. Terminal 106, in turn, seeks such information service without prior knowledge of local station 102 frequencies or prior knowledge of systems in which such information services may be obtained. Terminals 106 seek information services by content, i.e., system flags 208 or information service codes 210, found in broadcasts 104. The user merely presses a selected button 306 on its terminal 106, and need not engage an alternate communication channel, e.g., telephone the local paging system, to obtain particular information services on a limited basis and without formal subscription therefor.

It will be appreciated that the present invention is not restricted to the particular embodiment that has been described and illustrated, and that variations may be made therein without departing from the scope of the invention as found in the appended claims and equivalents thereof.

Claims

CLAIMS What is claimed is:

1. A personal information terminal comprising:

a dual channel radio signal receiving portion, said radio signal receiving portion being frequency agile and able to receive on selected radio signal frequencies including audio and data transmissions; an audio presentation portion presenting audibly an audio signal received by said radio signal receiving portion; and

a data presentation portion presenting and storing a data transmission received by said radio signal receiving portion.

2. A personal information terminal according to claim 1 wherein said data transmission is a paging message data signal.

3. A method of information service delivery comprising the steps: receiving a set of information service items in a plurality of information categories; broadcasting a first subset of said information service items in a first transmission channel, said broadcast of said first subset including indicia of information category found therein; broadcasting a second subset of said information service items in a second

transmission channel, said broadcast of said second subset including indicia of information category found therein; and responding at a remote information terminal to user demand for a given information category by seeking indicia corresponding to said given information

category in at least one of said first and second transmission channels.

4. A method according to claim 3 wherein said transmission channels correspond to radio signal broadcast, each radio signal broadcast operating at a separate transmission frequency.

5. A method according to claim 4 wherein said indicia is an information service code representing a category of information available in the corresponding transmission channel.

6. A method according to claim 1 wherein said transmission channels correspond to paging systems, each paging system being identified by a system flag in said transmission channel, said system flag representing availability of information services in the corresponding paging system.

7. A system delivering information services to remote information terminals, the system comprising: a radio signal transmission portion providing data transmission across a plurality of transmission channels; a transmission control portion collecting information items in a plurality of information service categories and broadcasting said items by way of said radio signal transmission portion in at least two of said transmission channels, each radio signal transmission including indicia therein corresponding to at least one information category available therein; and at least one of said remote information terminals including a user-interface allowing a user to demand information in a selected information service category and seeking in response thereto information service items in said category by monitoring at least one of said radio signal transmissions and comparing information

service category indicia therein to said selected information category.

8. A system according to claim 7 wherein each of said remote information terminals seek information service items on user demand.

9. A system according to claim 7 wherein said transmission channels

correspond to separate radio signal transmissions at different transmission frequencies.

10. A system according to claim 7 wherein said transmission channels correspond to separate paging systems each distinguished by a system flag available in a corresponding radio signal transmission.

11. A system of user demand information service delivery comprising: a paging system broadcasting by a plurality of radio signal transmissions data packets according to a given broadcast protocol, a first subset of said transmissions providing information service items in a first category of information services, a second subset of said transmissions providing information service items in a second category of information services, each transmission providing an information service item also providing indicia of information services available therein; a population of remote information terminals each selectively monitoring said radio signal transmissions, said terminals responding to a user demand for information services in a given category by seeking corresponding indicia in at least one of said transmissions and upon finding such indicia receiving a corresponding

information service item.

12. A system according to claim 11 wherein said radio signal transmissions operate at distinct broadcast frequencies.