 |
Description  |
|
|
FIELD OF THE INVENTION
This invention relates in general to communication systems and more
specifically to a selective call receiver within a communication system
capable of requesting information.
BACKGROUND OF THE INVENTION
Generally, selective call receivers sub:scribing to a paging system are
capable of receiving messages broadcast from the paging system addressed
to one or a group of selective call receivers. The selective call
receivers, by monitoring an assigned frequency, receive the messages from
a central transmitter. Each message intended for a particular selective
call receiver is encoded with the address of that selective call receiver
which notifies the selective call receiver that a message is being sent
from the central transmitter.
Some selective call receivers have acknowledge-back capability, that is,
the selective call receivers are capable of responding to the transmission
of an address from the central paging station by transmitting a short
message to the central paging system to confirm receipt of its address or
to redirect the message to an alternative selective call receiver.
Similarly, an acknowledge-back paging system include:s a central station
which broadcast messages to one or a group of selective call receivers
having acknowledge-back capabilities, the group of selective call
receivers, upon receipt of the message, transmit an acknowledge-back
response to the central station, preferably on a different frequency
sub-band being allocated to the selective call receivers in the group.
Additionally, some selective call receivers are capable of receiving
multi-recipient messages or information from various types of information
services, for example, stock markets, sports, weather and new reports,
etc. The multi-recipient messages, when transmitted, are capable of being
received by only those pagers who are authorized to access the
multi-recipient messages. Therefore, once a selective call receiver is
authorized to access multi-recipient messages, the selective call receiver
receives that type of message when it is being transmitted unless the
pager is turned-off. Accordingly, the selective call receivers receive
message only when the paging central station is transmitting and may
devote enormous amounts of time receiving a very long message which
shortens battery life because battery saving features are disabled when
the selective call receiver is receiving the multi-recipient messages from
an information services.
Thus, what is needed is a convenient and simple method for subscribing to a
plurality of information services.
SUMMARY OF THE INVENTION
A communication system comprises a base station having memory for storing
information within a plurality of information files relating to a
plurality of information services. A receiver receives an information
service request for requesting information within at least one of the
plurality of information files from a selective call receiver. A
transmitter transmits the information requested from within the at least
one information service file to the selective call receiver. The selective
call receiver includes a generator for generating the information service
request and a transmitter for transmitting the information service
request. The selective call receiver receives the information transmitted
from the base station in response to the information service request and a
display displays the received information.
In a communication system, a method for requesting information comprises
the steps of
(a) storing information in a base station within a plurality of information
files relating to a plurality of information services;
(b) receiving a request from a selective call receiver for information
within one of the plurality of information files;
(c) transmitting the information requested within the at least one
information service file to the selective call receiver requesting same;
(d) generating, in the selective call receiver, the information service
request;
(e) transmitting the information service request to the base station;
(f) receiving the information transmitted from the base station in response
to the information service requested by the selective call receiver; and
(g) displaying the received information.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a communication system in accordance with a
preferred embodiment of the present invention.
FIG. 2 is a block diagram of a hierarchy-tree-structure arrangement of a
plurality of information service in accordance with the preferred
embodiment of the present invention.
FIG. 3 is an information service request indicating an encoded codeword
designating an information service from which information is requested in
accordance with the preferred embodiment of the invention.
FIG. 4 is an electrical block diagram of a selective call receiver capable
of requesting information in accordance with the preferred embodiment of
the present invention.
FIG. 5 is an electrical block diagram of the microcomputer used in the base
station of FIG. 1 and the selective call receiver of FIG. 4.
FIG. 6 is a flow diagram illustrating the operation of the communication
system of FIG. 1.
FIG. 7 is a flow diagram illustrating t:he operation of the selective call
receiver of FIG. 4.
DESCRIPTION OF A PREFERRED EMBODIMENT
Referring to FIG. 1, a block diagram of a communication system is shown in
accordance with the preferred embodiment of the present invention. A base
station 100 includes a Radio Frequency (RF) transmitter/receiver 106
capable of transmitting and receiving information well known to those
skilled in the art. The transmitter/receiver 106 is coupled to a processor
104, the processor 104 having a decoder 118 for decoding information
service requests and other information received by the
transmitter/receiver 106. A memory 116 stores information relating to a
plurality of information service providers (or information services or
information service files) 60, 122-124, 126,128, and 130.
The plurality of information service providers 120,122-124,126,128, and 130
are preferably coupled to a telephone interface 120 which is coupled to
the processor 104. When the processor 104 receives information from the
plurality of information services 120,122-124,126,128 and 130, the
information is stored in memory. Access to the information files is
provided by a hierarchy-tree-structure unique to the information services
being subscribed to by each selective call receiver which is further
described below. The plurality of information services 120,122-124,126,128
and 130, as shown, is coupled to the processor 104 via the telephone
interface 120 for periodically receiving information to update the memory
116. A selective call receiver 200, as shown, is capable of requesting
information from a selected information service being subscribed to by
that selective call receiver 200 by transmitting the information service
request to the base station 100 to be described in detail below. The base
station 100, upon receipt of the information service request, accesses the
information from the selected information service file of the plurality of
information service files or directly from the service providers
120,122-124,126,128 and 130. FIG. 2 is an illustration of a
hierarchy-tree-structure arrangement of the plurality of information
service providers in accordance with the preferred embodiment of the
present invention. Accordingly, the base station 100 is shown coupled to
at least a subset of the plurality of information service providers. Some
of the information service providers have corresponding information
service files for storing information in memory 116 that is periodically
received from respective information service providers. Those of ordinary
skill in the art will appreciate that the plurality of information service
providers can be alternatively coupled to transmitters and receivers (not
shown) for providing communication between the base station 100 and the
plurality of information service providers. This information service files
store the most recent information as received from the respective
information service providers. This information is then readily accessible
to the selective call receivers 200 subscribing to that information
service. Access to the information service is shown categorized in blocks
of four according to the preferred embodiment o:f the present invention,
but any other number of categorizations will be equally suitable. By using
a four-level categorization, each of the four information services can be
accessed by encoding two bits in the information service request, for
example, communication by "00", information by "01", services by "10", and
others by "11". Further reference to FIG. 3 shows an encoded information
service request 300 according to the preferred embodiment of the present
invention.
For illustration, if a user of a selective call receiver 200 is requesting
information from "MY STOCKS" where FIG. 2 illustrates the subscription
list for the requesting selective call receiver 200, the user, by
selecting an appropriate switch, selects"INFORMATION" (FIG. 2) which
encodes "01" in the information service request position 1. A further
selection of "FINANCE" encodes "11" in the information request position 2.
Subsequent selections of "DOMESTIC", "STOCK MARKET", "NYSE", and finally,
"MY STOCKS" as shown by the bold directional arrow in FIG. 2 results in
the information service request being encoded with the series of bits
"011110010100", positions 1-6. The information service request 300 is then
encoded with the address of the selective call receiver 200 from which the
base station 100 determines whether the selective call receiver 200 has
access to the selected information service, and if so, the base station
100 retrieves the requested information. A similar
hierarchy-tree-structure access information is stored in memory of the
base station for each selective call receiver identifying the information
services and access to the information that are accessible by each
selective call receiver. Those skilled in the art will appreciate that
each selective call receiver 200 can have different information services
in its hierarchy-tree-structure because each selective call receiver can
subscribe to different information services. Accordingly, the subscription
list of the selective call receiver 200 is stored in the memory 116 of the
base station which uses the address of the information service request 300
to provide information back to the requesting selective call receiver 200.
In this way, each selective call receiver subscribes only to the
information services from which information is needed, the base station
stores the list of information services available to each selective call
receiver which is determined by an address assigned to each selective call
receiver. Additionally, by arranging the each subset of information
service being subscribed o by each selective call receiver in the
hierarchy-tree-structure, the information service request is encoded with
2.times.N bits which provides access information to 2.sup.N number of
information service providers.
FIG. 4 is an electrical block diagram of a selective call receiver in
accordance with the preferred embodiment of the present invention. The
selective call receiver 200 comprises an antenna 202 for intercepting
transmitted radio frequency (RF) signals which are coupled to the input of
a receiver 204. The RF signals are preferably selective call (paging)
message signals which provide a receiver address and an associated
message, such as numeric or alphanumeric message. However, it will be
appreciated that other well known paging signaling formats, such as tone
only signaling or tone and voice signaling, would be suitable for use as
well. The receiver 204 processes the RF signal and produces at the output
a data stream representative of a demodulated address and message
information. The demodulated address and message information are coupled
into the input of a decoder/controller 206 which processes the information
in a manner well known in the art. A power switch 210, coupled to the
decoder/controller 206, is used to control the supply of power to the
receiver 204, thereby providing a battery saving function as is well known
in the art for use with selective call receivers. The power switch 210
also provides power to a transmitter 212 which transmits the information
service request 300 (FIG. 3) to the base station 100.
For purposes of this illustration, it will be assumed that the POCSAG
signaling format is utilized which is well known in the art, although
other signaling formats could be utilized as well. When the address is
received by the decoder/controller 206, the received address is compared
with one or more addresses stored in a code plug (or code memory) 222, and
when a match is detected, an alert signal is generated to alert a user
that a selective call message, or page, has been received. The alert
signal is directed to an audible alerting device 214 for generating an
audible alert or to a tactile alerting device 216 for generating a silent
vibrating alert. Switches 220 allow the user of the selective call
receiver to select between the audible alert 214 and the tactile alert 216
in a manner well known in the art.
The message information which is subsequently received is stored in memory
(not shown) and can be accessed by the user for display using one or more
of the switches 220 which provide such additional functions as reset,
read, and delete, etc. Specifically, by the use of appropriate functions
provided by the switches 220, the stored message is recovered from memory
and processed by the decoder/controller 206 for displaying by a display
208 which enables the user to view the message. Specifically, the switches
220 include switches for selection of the information service providers
included in the subscription list and for encoding the information service
request 300 as discussed above. The switches 220 also include a transmit
switch (not shown) in accordance with the preferred embodiment for
transmitting the information service request 00 to the base station 100.
In this fashion, the user, by selecting the appropriate switches of
switches 220, encodes the information service request 300 which is
transmitted by pressing the transmit switch on switches 220 (not shown).
The controller/decoder 206 of FIG. 4 can be constructed utilizing a
microcomputer as shown in FIG. 5. FIG;. 5 is an electrical block diagram
of a microcomputer based decoder/controller suitable for use in the
selective call receiver of FIG. 4 or the processor of FIG. 1. As shown,
the microcomputer 206 is preferably an MC68HC05 microcomputer such as
manufactured by Motorola, Inc., which includes an on-board display driver
514. The microcomputer 206 includes an oscillator 518 which generates the
timing signals utilized in the operation of the microcomputer 206. A
crystal, or crystal oscillator (not shown) is coupled to the inputs of the
oscillator 518 to provide a reference signal for establishing the
microcomputer timing. A timer/counter 502 couples to the oscillator 518
and provides programmable timing functions which are utilized in
controlling the operation of the receiver or the processor. A RAM (random
access memory) 504 i:s utilized to store variables derived during
processing, as well as to provide storage of message information which are
received during operation as a selective call receiver. A ROM (read only
memory) 506 stores the subroutines which control the operation of the
receiver or the processor, as is well known to those skilled in the art.
It will be appreciated that in many microcomputer implementations, the
programmable-ROM (PROM) memory area can be provided by an EEPROM
(electrically erasable programmable read only memory). The oscillator 518,
timer/counter 502, RAM 504, and ROM 506 is coupled through an
address/data/control bus 508 to a central processing unit (CPU) 510 which
performs the instructions and controls the operations of the microcomputer
206.
The demodulated data generated by the receiver is coupled into the
microcomputer 206 through an input/output (I/O) port 512. The demodulated
data is processed by the CPU 510, and when the received address is the
same as the code-plug memory which couples into the microcomputer through
an I/O port 513, the message, if any, is received and stored in RAM 504.
Recovery of the stored message, and selection of the predetermined
destination address, is provided by the switches which are coupled to the
I/O port 512. The microcomputer then recovers the stored message and
directs the information over the data bus 508 to the display driver 514
which processes the information and formats the information for
presentation by a display such as an LCD (liquid crystal display). At the
time a selective call receiver address is received, the alert signal is
generated which can be routed through the data bus 508 to an alert
generator 516 that generates the alert signal which is coupled to the
audible alert device that was described above. Alternatively, when the
vibrator alert is selected as described above, the microcomputer generates
an alert enable signal which is coupled through data bus 508 to the I/O
port 513 to enable generation of a vibratory, or silent alert.
The battery saver operation is controlled by the CPU 510 with battery
saving signals which are directed over the data bus 508 to the I/O port
512 which couples to the power switch. Power is periodically supplied to
the receiver to enable decoding of the received selective call receiver
address signals and any message information which is directed to the
receiver or to the transmitter.
FIG. 6 is a flow diagram illustrating the operation of the communication
system in FIG. 1. Operationally, the base station 100, after power-up
(step 600), waits to receive information, step 602. According to the
preferred embodiment of the present invention, the information received
comprises either a request for information service from the selective call
receiver 200 or information from any of the plurality of information
service providers or information services coupled to the base station.
Step 604 determines if the received information is an information service
request. If it is determined otherwise, the received information is stored
in the information service file being allocated for that type of service
information, step 606. However, when the received information is the
information service request, the processor of the base station decodes the
address of the selective call receiver requesting information, step 608,
and decodes the information service request to determine the information
file in which the information being requested according to the
hierarchy-tree-structure of the preferred embodiment, step 610. In step
612, the processor determines if that selective call receiver has access
to the information service being requested. If the selective call receiver
has no access to the information being requested, the base station
terminates further processing, step 614. When access is available, that
is, when the selective call receiver has requested information from a
information service being subscribed to by the selective call receiver,
the base station determines whether the information requested is stored in
memory in one of the plurality of information service files, step 616. If
no, the base station sends out a request via a modem or other suitable
transmitting means well known in the art, step 618. Such a request may
include a request for help, for example, medical or police services, etc.
In step 616, when the requested information is stored in one of the
plurality of information files, the request information is retrieved, step
620, and encoded by well known techniques for subsequent transmission. The
information is then transmitted at the first data rate over a
communication channel to the selective call receiver, step 622. As is well
known, the information being transmitted to the selective call receiver is
preferably transmitted at a high data rate in a wide band channel, for
example, 32 kbps, 64 kbps, etc. because of a high power transmitter which
is available at the base station.
Further in FIG. 7, a flow diagram of the operation of the selective call
receiver of FIG. 4 is shown. Operationally, when the user of the selective
call receiver desires information relating to any of the subset of the
plurality of information services that are subscribed to, the user,
subsequent to power-up (step 700), presses the switches as discussed in
FIG. 4 to encode the information service request for requesting
information from the desired information service, step 702. The
information service request is encoded according to the
hierarchy-tree-structure for designating the selected information service,
step 704. The encoded information service request is then combined with
the address of the selective call receiver, step 706, and then transmitted
to the base station, step 708.
In this way, the information being encoded in the hierarchy-tree-structure
for designating the information service allows the selective call receiver
to access the plurality of information service or information service
providers with the fewest number of bits in the information service
request. Also, because the selective call receiver is a low power device,
using the fewest number of bits is attractive because lower power will be
expended to transmit the information service request when the transmission
is constrained in a narrow band channel hav | | |
