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PCT 

INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) 



(51) International Patent Classification 6 : 

H03M 13/00, H04L 1/18, H04M 11/00 



(11) International Publication Number: WO 97/26709 

(43) International Publication Date: 24 July 1997 (24.07.97) 



(21) International Application Number: PCT/US97/00823 

(22) International Filing Date: 16 January 1997 (16.01.97) 



(30) Priority Data: 

08/588.165 18 January 1996 (18.01.96) 



(71) Applicant: POCKETSCIENCE, INC. [US/US]; P.O. Box 

391 143, Mountain View, CA 94039 (US). 

(72) Inventors: FULLAM, Scott, F.; 2149 Junction Avenue #12, 

Mountain View, CA 94043 (US). PERETZ, Neil, M.; P.O. 
Box 391 143, Mountain View, CA 94039 (US). 

(74) Agent: LOHSE, Timothy, W.; Gray Cary Ware & Freidenrich. 
400 Hamilton Avenue, Palo Alto, CA 94301-1825 (US). 



(81) Designated States: AL, AM, AT. AU, AZ, BA, BB, BG, BR, 
BY, CA, CH, CN, CU, CZ, DE, DK, EE. ES, FI. GB, GE, 
HU, IL, IS, JP, KE. KG, KP, KR, KZ. LC, LK, LR, LS. 
LT, LU, LV, MD, MG. MK, MN. MW, MX, NO. NZ, PL. 
PT, RO. RU, SD, SE, SG, SI, SK, TJ, TM, TR, TT, UA, 
UG. UZ, VN, ARrPO patent (KE. LS, MW. SD, SZ, UG), 
Eurasian patent (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), 
European patent (AT, BE. CH, DE, DK. ES. FI, FR, GB, 
GR, IE, IT, LU, MC, NL, PT. SE). OAPI patent (BF. BJ, 
CF, CG, CI, CM, GA, GN, ML, MR, NE, SN, TD, TG). 

Published 

With international search report. 



(54) Title: ELECTRONIC MESSAGING SYSTEM AND METHOD 




30 



HFAXOutputl 
H E-mail Output k 32 
. |Pager Output k ~34 



A multi-function el 



messaging system (18) for transmitting messages over a first communications link (24) having a remote 
(22) for generating forward error corrected signals representing various types of electronic messages, for generating acoustical tones 
corresponding to the error corrected signals is provided. The acoustical tones are coupled to the send-only first communications link (24) 
and transferred to a computer (20). The computer sends an acknowledgement signal back to the user of the remote unit (22) over the first 
communications link (24) and decodes and error checks the signals. The computer (20) also reformats the various messages and resends 
vanous communication links depending on the ultimate destination of the message. The computer (20) may also send 
messages to the remote unit (22) over a receive-only second communications link (36). 



FOR THE PURPOSES OF INFORMATION ONLY 



Codes used to identify States party to the PCT on the front pages of pamphlets publishing international 
applications under the PCT. 



Central African Republic 



Kyrgyslan 

Democratic People's 
of Korea 

Republic of Korea 



Poland 



SE Sweden 

50 Singapore 

51 Slovenia 



MC Monaco 



UA Ukraine 



VN Viet Nam 



WO 97/26709 



PCT/US97/00823 



ELECTRONIC MESSAGING SYSTEM AND METHOD 

BACKGROUND OF THE INVENTION 

The present invention relates generally to an electronic messaging system, 
and more particularly to an inexpensive, portable electronic messaging system and 
method that allows transmission of facsimile, electronic mail and pager messages 
over a first communications link, as well as reception of incoming messages over a 
second communications link. 

Prior to the proliferation of computers, people communicated 
store-and-forward style messages (i.e., messages that are first stored in some 
manner and then later forwarded) using facsimile machines and direct 
computer-to-computer data connections over existing and leased telephone lines. 
As computers became cheaper and easier to use, people began using more 
advanced facsimile machines, computer facsimile modems, and direct 
computer-to-computer modem connections to transfer information between each 
other. 

More recently, people began to use commercial on-line services to 
communicate large amounts of store-and-forward style information (i.e., electronic 
mail) with each other. Now, a new medium for communicating, the Internet, is 
attaining general public popularity. In the last five years, the number of people 
connected to the Internet has increased because the Internet allows users who 
have an Internet account, a modem, and a computer to communicate great 
amounts of information with each other, regardless of each party's method of 
accessing the Internet or the geographic location of their Internet access point, at 
minimal expense. For example, for the cost of a local telephone call, a person in 
California can send a long electronic mail (e-mail) message to a friend (who also 
must have Internet access) anywhere in the world. Due in large part to the 
Internet, the popularity of electronic store-and-forward messaging, such as e-mail, 

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WO 97/26709 ^ PCTYUS97/00823 

has also increased exponentially. 



Initially, due to the large size of computers, people typically only accessed 
the Internet from a desktop computer. Later, as the size of computers decreased 
from desktops to notebooks to palmtops, people could carry their computer with 
them wherever they go and access their e-mail account from any location where 
they could locate a telephone jack to connect, via modem, to the Internet. 

At the same time that e-mail was increasing in popularity, paging technology 
was also increasing in popularity. Many people carry pagers to ensure that others 
can easily reach them at any time. In addition, a new product category of portable 
computer, known as a personal digital assistant (PDA) was introduced. The PDAs 
are basically very small handheld computers (several of which offer limited 
messaging capabilities, such as paging or e-mail), but are priced too high (i.e., in 
excess of $500) for purchase by the average consumer and do not offer 
communication features well-tailored to the average consumer user's needs. 

Today, a number of PDAs are on the market. One well-known PDA has a 
small touch-sensitive screen controlled by special user-interface software. This 
PDA also has a modem that allows a user to communicate with a computer 
network and to send e-mail messages, facsimiles, and pager messages. This PDA 
and its accessories, however, are very expensive, and require that the user locate a 
phone jack for message transmission and reception. In these well known current 
PDA systems on the market today, all messages are transmitted and received over 
the same communications link, which requires an expensive modem and extensive 
handshaking time between the modem in the PDA and the modem to which the 
PDA is connected. 



A second well known PDA is a cellular telephone with a touch-sensitive 
backlit display that acts as a keyboard. This second PDA has the ability to send 
facsimiles, to communicate with commercial on-line services, and to manage a 
user's schedule with a built-in time management system. This second PDA, 
however, is also very expensive and too large and heavy to carry around in a 



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user's pocket. In addition, due to this PDA's circuit-switched communications, 
costs can be very high because it can only communicate over more expensive 
cellular telephone systems, rather than using less expensive landline telephones 
and short-burst packet data transmission protocol. In addition, because this PDA 
relies solely on cellular communications, it has relatively high power consumption, 
which leads to a very short battery life. 

All of the known messaging systems that allow a user to both send and 
receive multiple types of electronic messages (i.e., facsimile, pager and e-mail) are 
too large, too expensive, too inconvenient (i.e., they require telephone connectivity 
through an RJ-1 1 telephone jack) or drain a battery too quickly. In addition, these 
known systems cannot send a message reliably over a normal public pay 
telephone line or many cellular links due to occasional line noise problems that 
cannot be corrected by known systems, and due to a lack of more convenient (i.e. 
appropriate acoustic) telephony coupling technology. In addition, none of these 
known systems provide an inexpensive way to send different types of messages 
and also provide the user with an audible acknowledgement signal from the 
receiving computer indicating whether or not the message is sent correctly. 

Thus, there is a need for an electronic messaging system that is inexpensive 
and transmits various types of electronic messages over any type of 
communications link. There is also a need for an electronic messaging system that 
has a system for sending an audible acknowledgement signal back to the user and 
a system for performing multiple levels of error detection and correction. The 
electronic messaging system in accordance with the invention addresses the above 
problems of conventional messaging systems and it is to this end that the invention 
is directed. 

SUMMARY OF THE INVENTION 

The invention provides an inexpensive, portable electronic messaging 
system and method that may be easily coupled to a communications link, such as 
a pay telephone handset. It may send any type of electronic messages over a first 



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WO 97/26709 PCT/US97/00823 
4 

communications link. The electronic messaging system also receives incoming 
messages over a second communications link that is separate from the first 
communications link. 

The electronic messaging system may also send electronic mail, facsimiles, 
and paging messages over the same first communications link, through a 
computer; and allow a user to receive immediate audible feedback, (i.e., a signal 
acknowledging the receipt of the transmitted data) over the first communications 
link from the computer. 

The electronic messaging system of the invention also may have a forward 
error correction scheme that increases the reliability of message transmission over 
a noisy communications link. The error correction scheme may include multiple 
levels of error detection and correction to further increase the message 
transmission reliability. The error correction levels may include data packet level 
error correction, resending corrupt data packets in response to a corrupt data 
packet acknowledgement signal from a central computer, and bit level error 
correction. 

The electronic messaging system and method of the invention may employ 
a computer and a unit remote to the computer for communicating data between 
the computer and the remote unit. The remote unit may have a system for 
receiving input from a user and for producing electrical signals corresponding to 
the input data. The remote unit may also have a system for producing error 
corrected data based on the electrical signals and for producing acoustical tones 
corresponding to the error corrected data. The remote unit may also have a 
system for coupling the acoustical tones to a first communications link for 
transmission to the computer. 

The computer may have a system for detecting and correcting errors in the 
data represented by the acoustical tones and a system for sending a signal back 
to the user of the remote unit over the first communications link to acknowledge 
receipt of the acoustical tones. The remote unit, in addition, may have a system for 



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5 

receiving data from the computer over a second communications link. 

The electronic messaging system also may have a method of error detecting 
and correcting data in the computer that includes checking data packets for errors, 
resending any data in which any data packets contain any errors, comparing the 
data packets to the resent data packets, and comparing each bit in the data 
packets to each bit in the resent data packets to determine a correct bit. The 
method may generate an integrity flag, for each data packet, that indicates errors 
within each data packet. 

BRIEF DESCRIPTION OF THE DRAWINGS 

Figure 1 is a schematic diagram of an embodiment of the electronic 
messaging system of the present invention including a computer and a unit remote 
to the computer for communicating electronic messages between the computer 
and the remote unit; 

Figure 2 is a block diagram of an electronic messaging system in 
accordance with the invention that has a plurality of remote units communicating 
with the computer; 

Figure 3 is a front view of the remote unit shown in Figure 1 ; 

Figure 4 is a side view of the remote unit shown in Figure 1 ; 

Figure 5 is a back view of the remote unit shown in Figure 1 ; 

Figure 6 is a top view of the remote unit shown in Figure 1 ; 

Figure 7 is a more detailed block diagram of the remote unit shown in 
Figures 3-6; 

Figure 8 is a more detailed block diagram of the telecommunications 
interface that sends incoming messages to the computer of Figure 1 ; 

Figure 9 is a flowchart showing a method of processing an incoming 
message from a remote unit that may be carried out by the incoming message 
system within the computer; 

Figure 10 is a schematic diagram showing the electronic messaging 
communications transfer protocol; 

Figure 1 1 is a flowchart of a method of multiple error detection and 



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WO 97/26709 PCT7US97/00823 

correction of the invention that may be carried out by the incoming message 
system; 

Figure 12 is a schematic diagram of the error packet overlay error correction 
method that is part of error correction method shown in Figure 1 1 ; 

Figure 1 3 is a flowchart of the error packet overlay error correction method 
shown in Figure 12; and 

Figure 14 is a schematic diagram of the majority bit voting packet error 
correction method, shown in Figure 1 1 . 



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 

The present invention is generally applicable to an electronic messaging 
system that can transmit electronic messages, such as facsimile messages, pager 
messages, and e-mail messages. The electronic messaging system in accordance 
with the invention will be described in that context. It will be appreciated, however, 
that the system and method of the invention has greater utility. 

The multi-function electronic messaging system in accordance with the 
invention may include a computer, and a hand-held, portable, battery powered unit. 
The unit is located remotely from the computer and generates and transmits 
electronic messages, such as pager, facsimile, and e-mail messages, over a first 
communications link to the computer, and receives incoming messages from the 
computer over a second communications link. The remote unit may also have a 
display device and an input device for creating and viewing messages. The 
remote unit may also have a coupling system so that signals from the remote unit 
may be coupled to and transmitted through the first communications link. The 
computer of the electronic messaging system may receive the incoming remote 
unit electronic messages, may detect and correct errors in remote unit signals, and 
may transmit an audible signal back to the user of the remote unit, over the first 
communications link, indicating receipt of the remote unit signals. The computer 
may also transmit the various types of electronic messages from the remote unit 



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WO 97/26709 ^ PCT/US97/00823 

(i.e., e-mail, pager, and facsimile) over various appropriate outputs, and transmits 
messages back to the remote unit over a second communications link. 

Figure 1 is a schematic diagram of an electronic multi-function messaging 
system 1 8 embodying the invention. As shown, the electronic messaging system 
18 may include a computer 20, and a portable unit 22 remote to the computer. A 
first communications link 24, such as an ordinary telephone line, may connect the 
remote unit 22 to the computer 20 to permit the transmission of messages from the 
remote unit to the computer. The remote unit preferably generates acoustic tone 
patterns (V.23 CCITT originating station modem tone frequencies to indicate a 
serial 1/0 bit stream) representing various types of electronic messages created by 
a user. The acoustic tones may be output by an output device 26, such as a 
speaker, and transmitted over the first communications link to the computer, which 
interprets the tones from the remote unit using a data receiver modem 28, that is 
described below in more detail. The computer may detect and correct errors in the 
data, as described below, sent to it by the remote unit, and may generate an 
audible signal that is sent back to the user of the remote unit over the first 
communications link. The signal may indicate a sufficiently error-free data 
transmission or may indicate that the data must be resent because the 
transmission is not sufficiently error-free. 

The computer may also separate out the individual types of messages 
according to their ultimate destination (i.e., facsimile, e-mail, and pager messages), 
and send those messages to the appropriate sub-system within the computer that 
transmits the messages (i.e., a facsimile machine sub-system for transmission of 
facsimile messages). In the system shown in Figure 1, the computer may have a 
facsimile output 30, an e-mail output 32 and a pager output 34. The multi-function 
electronic messaging system according to the present invention may process any 
other type of electronic messages and may also have additional types of functions, 
such as a voice messaging system. The computer may also send incoming 
electronic messages to the remote unit over a second communications link 36, as 
will be described below. 



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WO 97/26709 

8 



The separation of the first communication link for transmitting data from the 
second communications link for receiving data provides many advantages. In 
particular, the first communications link is used solely for unidirectional transmission 
of messages from the remote unit (i.e., send-only, with no handshaking between 
the computer and the remote unit), in packet form, and the second 
communications link is used solely for unidirectional transmission of messages from 
the computer to the remote unit (i.e., receive-only, with no handshaking between 
the computer and the remote unit), in packet form as well. This unidirectional 
transmission of packetized messages is faster than traditional bi-directional 
transmission because the bi-directional transmission requires handshaking and 
greater synchronization between the remote unit and the computer. The 
unidirectional transmission also may maximize the use of the most convenient 
communications link for time-sensitive messages from the computer to the remote 
unit, and may use more affordable bandwidth for the transmission of messages 
from the remote unit to the computer. 

In this embodiment, the second communications link may be a wireless 
pager frequency link. To receive the incoming pager messages, the remote unit 
may have a pager receiver 38. In addition, the first communications link may be a 
pay telephone line with a receiver handset 40, and the remote unit speaker is held 
against the telephone handset microphone to couple the acoustical tones to the 
telephone line. The first and second communications links may be any type of 
communications link, and are not limited to the examples shown in Figure 1 

Figure 2 is a block diagram of the computer 20 connected to a plurality of 
remote units 50, 52, 54, 56 and 57. The remote units may be connected to the 
computer, as shown, through a variety of different first communication links, such 
as a public telephone line 58, an office public broadcast exchange (PBX) 60, a 
hotel telephone switchboard and branch exchange 62. an ISDN link 64, or a 
cellular telephone link 66 through a cellular base station 68. In addition, as 
described above, the remote units may also have a built-in or external pager radio 
receiver (not shown), so that the remote units carr receive incoming pager 
messages over the second communications link, such as radio pager system 70. 



SUBSTITUTE SHEET (RULE 26) 



WO 97/26709 g PCT/US97/00823 

All of the remote units attached to the different first communications links, are 
connected to the computer by a Public Switched Telephone Network (PSTN) 72 
that may handle a plurality of telephone calls from remote units by switching the 
calls to various incoming telephone lines and a plurality of modems (not shown) in 
the computer. The modems are connected to a telecommunications interface 74 
sub-system of the computer that interprets and translates (converts) the incoming 
acoustical tones from the remote units into electronic digital form. The 
telecommunications interface then forwards the interpreted incoming remote unit 
data to an incoming message System 76 that processes the incoming data from 
the remote units, and detection and correction of errors is performed in an error 
detection and correction system 78, and routes the messages to the appropriate 
outgoing systems, as described below. The operation of the incoming message 
system will be described below with reference to Figure 9. All of the computer 
systems may include microprocessors or multi-tasking computer servers and are 
connected together by a backbone network 80, such as an Ethernet network, so 
that all of the systems within the computer may exchange data with each other. In 
this embodiment, the outgoing systems shown are an outgoing facsimile system 
82, an e-mail system 84, a pager system 86, a billing, message and user profile 
system 88, and a backup system 90. The invention is not limited to the outgoing 
systems shown and may have other systems, such as a voicemail system. 

If some of the data received by the incoming message system 76 is a 
facsimile message, then the message is first error detected and corrected in the 
error detection and correction unit 78 and then routed over the backbone network 
to the outgoing facsimile system 82, that may have a facsimile machine 92 or 
server attached to it for sending outgoing facsimile messages. If some of the data 
received by the incoming message system is an outgoing electronic mail (e-mail) 
message, the message is routed to the e-mail system 84, and then over an 
electronic mail channel, such as the Internet. For an incoming e-mail message to 
the remote unit user, the e-mail message is received by the e-mail system and 
routed to the pager system 86, which sends the message to the remote unit 
through a paging terminal and transmitter 70 in the form of a pager message. If 
some of the data received by the incoming message system is an outgoing pager 



SUBSTITUTE SHEET (RULE 26) 



WO 97/26709 PCT/US97/00823 
10 

message, then the message is routed to the pager system 86 that is connected to 
the paging terminal and transmitter 70. 



The billing, message and user profile system 88 stores all of the information 
necessary to keep track of billing, message usage, and user profiles. The billing, 
message and user profile system may also have a database 94 and an archival 
storage device 96, for short term and long term storage, respectively, of the user 
profiles and billing information. The database also stores audible messages (i.e. 
prerecorded voice messages) that may be sent to the user of the remote unit user 
over the first communications link (i.e., as an acknowledgement that data from the 
remote unit has been properly received). The back-up system 90 may include a 
back-up facsimile system, a back-up e-mail system, a back-up pager system, a 
back-up incoming Message system and a back-up billing, message and user 
profile system that are all connected together by a back-up network. The details of 
the back-up system are not shown. This back-up system provides redundancy 
within the computer to reduce lost data due to crashes and other possible 
malfunctions and mishaps. 



Figures 3, 4, 5 and 6 show a front, side, back and top views, respectively, 
of a preferred implementation of the remote unit 22. It may include a display 
device 100, such as a liquid crystal display (LCD), and a user input device 102, 
such as a keyboard. The input device receives information from the user, such as 
text messages, and later generates electrical signals corresponding to those 
electronic messages. The display device displays any electronic messages created 
by the user and displays any incoming messages. The display device also 
displays the address book, the calendar, and any other programs that are resident 
in the remote unit memory. To initiate the transfer of data from the remote unit to 
the computer, the remote unit may have a send button 104. On the back side of 
the remote unit, as shown in Figure 5, there may be a battery compartment 106 
and the sound output device 26, such as a speaker. The sound output device 
outputs modulated data tones (V.23 outgoing compatible tones) generated by a 
one-way acoustic data modulator (not shown) inside the remote unit. The sound 
output device permits the remote unit to communicate to the computer by coupling 



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11 

the acoustical tones to the first communications link, such as an ordinary telephone 
line as shown in Figure 1. On the end of the remote unit, as shown in Figure 4, is 
an interface port 108 so that a user can transfer data, such as e-mail addresses, 
calendar appointment records and saved e-mail messages, between the remote 
unit and a personal computer. As shown, the remote unit may be a small, 
handheld, pocket-sized, battery powered messaging system. 

Figure 7 is a detailed block diagram of the remote unit 22, that may include 
the input device 102 that have a plurality of keys including the SEND key 104, as 
described above. The remote unit may also have a central processing unit (CPU). 
120 that controls the operations of the remote unit, may generate forward error 
corrected data based on the electrical signals generated by the input device, and 
may generate acoustical tones for communicating the forward error corrected data 
to the computer. The CPU may also generate the acoustical tones from the 
electrical signals if no error correction is conducted on the electrical signals. The 
remote unit may also have an external memory unit 122 for storing data and 
software programs that run within the CPU, the display device 100 for displaying 
messages, an incoming message receiver 124, such as a pager system for 
receiving incoming messages from the computer, and a coupling system 1 26 for 
coupling the acoustical tones generated by the CPU to the first communications 
link (not shown). The memory unit may store an address book program, address 
book data, a calendar program, calendar appointment records, stored outgoing 
message data, an encryption system, an error correction system, and a plurality of 
incoming messages. 

The CPU 120 may have a plurality of interfaces (not shown) that connect 
various input and output devices to the CPU, such as the input device 102, a 
power switch 128, a real-time clock 130, the display device 100, a PC interface 
system 132, the incoming message receiver 124, the external memory unit 122, 
and a user alert system 134. The external memory unit may include a ROM 136, 
an SRAM 138, and an EEPROM 140. The ROM may store various program code, 
including the software for generating the DTMF acoustical tones and the modulated 
data tones. The SRAM may store incoming and outgoing messages. The 



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WO 97/26709 PCT/US97/00823 

combination of a special battery switching circuit (not shown) and the SRAM 
means that the SRAM memory contents (incoming and outgoing message data) is 
not lost when the power is shut off to the remote unit. The EEPROM may store 
various data, such as a remote unit identification number, any e-mail screening 
criteria (described below), any encryption key, and any other configuration data. 

The power switch 128 turns the remote unit on and off. The real-time clock 
130 dates and time stamps all the outgoing messages, and provides a real time 
clock to the user. The display device 100 may also have an LCD driver 142 that 
controls the output device, and a light emitting diode (LED) 144 for backlighting the 
output device to allow viewing of the output device under low light conditions. 

The outgoing and incoming messaging systems within the remote unit will 
now be described. The incoming messages may be received over the second 
communications link, such as pager frequencies, by the incoming message 
receiver 124 that may include a pager antennae 146, a pager receiver 148, and a 
pager protocol decoder 150. If a different type of second communications link is 
used, such as a wireless link, then another type of incoming message receiver may 
be used. 



The outgoing messages of the remote unit may be coupled to the first 
communications link. For outgoing messages, a program stored in the ROM may 
generate electrical signal corresponding to messages input by a user with the input 
device. As described above, error corrected signals may also be generated by the 
CPU, depending on the type of error correction is selected by the user. Then, a 
software based tone generator, stored in the ROM, generates acoustical tones 
corresponding to the electrical signals or the error corrected electrical signals. 
Once the acoustical tones are produced, the tones are sent to the coupling system 
126 where the tones are converted to a digital signal by a digital-to-analog 
converter 152. amplified by an audio amplifier 154, and output by the speaker 26. 
The acoustical tones, generated by the speaker, as described above, may be 
coupled to a first communications link 24 by, for example, holding the speaker near 
the pay telephone handset microphone 40, as shown in Figure 1 . 



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13 

The remote unit may also have the PC interface system 132 that may include 
an RS232 interface 156 that sends data from the remote unit over an RS232 port 
(not shown) to a personal computer (not shown) and receives data from a 
personal computer over the RS232 port and converts that data into remote unit 
compatible data. The user alert system 134 may include a vibrating buzzer 158, a 
piezoelectric beeper 160, and an LED 162. All of these devices are used to notify 
the user of the remote unit of various conditions. For example, the vibrator may 
vibrate to notify the user that an incoming message has been received. Similarly, 
the buzzer and the LED may also be used to notify the user. 

The operation of the electronic messaging system for generation and 
transmission of messages from the remote unit to the computer will now be briefly 
described. Once a remote unit user has entered a message into the remote unit 
using the input device, such as a keyboard or touch sensitive screen, the user 
indicates how the message is going to be sent (i.e., by facsimile, e-mail or pager). 
The user may also enter multiple messages to be ultimately sent through a variety 
of transmission methods and mediums. The user may also view the messages that 
he is creating using the output device. Once all of the messages have been 
entered and stored, the CPU of the remote unit generates electrical signals 
corresponding to the electronic messages of the user and also, if the option is 
selected, the remote unit produces forward error corrected signals corresponding 
to the electrical signals. Then, the user can go to a first communications link, such 
as a pay phone or any other communications link, such as cellular telephone, and 
dial an access number that connects the user to the computer. 

Once the user connects to the computer, the computer will request, via an 
audible message (i.e., a prerecorded voice message), that the user place the 
remote unit speaker against the telephone handset microphone, and initiate the 
message transfer from the remote unit to the computer. When the user depresses 
the SEND button, the CPU and software based tone generator generate acoustical 
tones corresponding to either the electrical signals or the forward error corrected 
electrical signals. The remote unit couples the acoustical tones to the first 
communications link using the speaker and the messages, in the form of electrical 



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WO 97/26709 PCT7US97/00823 

signals, are transferred to the computer. The messages that are sent by the 
remote unit to the computer may be encrypted for security or compressed to 
decrease the sending time. The messages may also be forward error corrected, 
described above. 



Once the message transfer is complete, the computer, using an error 
correction and detection method that will be described below, tests the message to 
determine if the message is sufficiently error-free. In the computer determines that 
the messages are sufficiently error-free, the computer then audibly notifies the user, 
using a synthesized or pre-recorded voice message or a tone, that the transfer of 
messages was successful. If the computer determines that the message contains 
too many errors, the computer will play a different audible message through the 
first communications link to tell the user to resend the message. The details of the 
messaging transfer protocol, and the error correction method will be described in 
more detail below. 



Figure 8 is a detailed block diagram of the telecommunications interface 74 
that is part of the data receiver modem 28, shown in Figure 1. The modem may 
include a modem CPU 180, a memory unit 182, a message transceiver 184, and ar 
incoming message system interface 186. The modem CPU may have a first UART 
port 188 that communicates with the incoming message system interface, such as 
an RS232 level shifter 190 to communicate data back and forth between the 
incoming remote unit server and the data receiver modem. A second UART port 
192 in the CPU connects to the message transceiver for receiving remote unit data 
(acoustical tones) and transmitting a signal acknowledging receipt of the remote 
unit data back to the user of the remote unit over the first communications link. 

The memory unit 182 may have a RAM 194 that may act as a buffer for the 
incoming electronic messages and may temporarily store program information and 
variables, such as the set-up information for each particular remote unit. The 
memory unit may also have a ROM 196 for storing software programs that run on 
the modem CPU. The incoming data from the remote unit and outgoing 



SUBSTITUTE SHEET (RULE 26) 



WO 97/26709 PCT/US97/00823 
15 

acknowledgement signals to the user of the remote unit go through the message 
transceiver that may include a telecommunications interface 1 97, a first and second 
amplifier 198, 200, and a data demodulator 202. The incoming data from the 
remote unit may be carried over the first communications link (not shown) to 
another communications network, such as a Public Switched Telephone Network 
(PSTN) 204, or the first communications link itself may be the PSTN. The incoming 
tones are converted to electrical signals by the telecommunications interface, 
amplified by the first amplifier, demodulated by the data demodulator, and enter 
the modem CPU through the UART port. For outgoing acknowledgement signals 
sent out over the PSTN and any other first communications link, the modem CPU 
signals another sub-system (not shown) within the computer to generate a signal, 
such as a synthesized or pre-recorded audio message. The modem CPU also 
controls this signal by controlling the enabling signal to the second amplifier 200. 
Thus, the signal is fed into the second amplifier, through the telecommunications 
interface, and transmitted over the PSTN 204 or any other first communications link 
back to the user of the remote unit. The telecommunication interface 197 is 
controlled by an ON/OFF hook signal (the phone line is switched between on and 
off hook conditions) generated by the modem CPU. An incoming ring condition 
from the PSTN generates a ring detect signal that is fed into the modem CPU, 
causing the modem CPU to activate the telecommunications interface. 

Fig. 9 is a flowchart showing the operation taken by the incoming message 
system 76, shown in Figure 2, for processing an incoming remote unit message. 
At 220, the telephone call from the user with the remote unit is answered by the 
incoming message system and, at 222, the incoming message system plays an 
audible message, such as a synthesized or pre-recorded voice message, 
instructing the user to "Send the data now" by holding the remote unit next to the 
telephone handset microphone and pressing the Send button. The voice message 
played by the incoming message system may be stored in the database, shown in 
Fig. 2. Then at step 224, the incoming message system receives data from the 
remote unit, including any outgoing message data, any new e-mail screening 
criteria, and a log of pager messages received by the remote unit since last 
communication with the incoming message system. 



SUBSTITUTE SHEET (RULE 26) 



WO 97/26709 PCT/US97/00823 
ib 

The e-mail screening criteria allow the computer to automatically screen 
e-mail messages ultimately destined for the remote unit user. For example, 
messages that are sent from a person considered particularly annoying by the user 
of the remote unit may be screened out. The pager message log is used to 
ensure that the remote unit user receives all of his/her incoming pager messages 
and to cause the computer to retransmit any lost pager messages. After the error 
correction and detection is performed at 225, at 226, it is determined whether or 
not all of the data received from the remote unit is sufficiently error-free. The error 
detection and correction that occurs in the incoming message system when a 
message is received will be described in more detail below with reference to Figure 
11-14. If the data contains too many errors, then control goes back to 222, 
where the incoming message system plays an audible message requesting that the 
data be resent. However, if the data is sufficiently error-free, then at 228, the 
incoming message system plays another audible message that tells the user that 
the data was received clearly. The messages played by the incoming message 
system may be stored in the database, shown in Figure 2. After the data received 
message is played, the incoming message system hangs up the phone at 230. 

After hanging-up the phone with the user, the further processing of the 
incoming data stream begins (232). The incoming data is separated into the e-mail 
screening criteria, as described above, the incoming messages (each being 
separated according to its ultimate destination), and the log of previously received 
pager messages, as described above. Then, the log of previously sent pager 
messages is analyzed (234) and compared to the log of previously received pager 
messages, and it is determined if all paging messages sent to the user's remote 
unit were properly received since the user last uploaded data to the incoming 
message system (236). If the user's remote unit has not properly received all of 
the previously sent pager messages, then the incoming message system locates 
the user's missing/lost pager messages in the database (238), shown in Figure 2, 
and uploads them to the paging system, shown in Figure 2, for re-transmission to 
the remote unit. 

Once any missed pager messages have been re-transmitted, or once all 



SUBSTITUTE SHEET (RULE 26) 



WO 97/26709 PCTYUS97/00823 
17 

previously sent pager messages have been confirmed as received, then the 
incoming message system at 240, forwards any changes in the e-mail screening 
criteria to a user records database stored in the database, shown in Figure 2. 
Then, at 242, any outgoing messages are forwarded to an outgoing message stack 
and control in the computer is now transferred, at 244, to the individual systems 
that handle the various types of outgoing messages. For example, if the outgoing 
messages contained an e-mail message and a facsimile message, then control 
would go to the facsimile system and to the e-mail system. The various message 
systems in the computer may also operate simultaneously and independently and 
process several different messages simultaneously. 

Figure 1 0 is a schematic diagram showing the transfer communications 
protocol between the remote unit and the computer during data transfer. The 
transfer protocol provides a way of identifying the remote unit to the computer, a 
method of verifying that the data has been received correctly, and a way of 
requesting that the data be resent if it is received unclearly. As shown, there may 
be six phases of a data transfer between the remote unit and the computer, 
including a dial phase 260, a connect phase 262, a preamble transmission phase 
264, a data transmission phase 266, an acknowledgement phase 268, and an end 
phase 270. 

In the dial phase 260 and connect phase 262, a connection through a first 
communication link, such as a telephone line, is established between the user of 
the remote unit and the computer. The computer may generate an audio tone, or 
synthesized voice welcome message instructing the user to begin sending data. 
Once connected, the user holds the speaker of the remote unit close to the 
telephone handset microphone and presses the SEND button of the remote unit to 
initiate the preamble phase of the communications protocol between the remote 
unit and the computer. 

In the preamble phase 264, the remote unit sends preamble data to the 
computer. The preamble data may include a synchronization part, a remote unit 
identification number, features data, a time and date stamp, error correction type 



SUBSTITUTE SHEET (RULE 26) 



WO 97/26709 PCT/US97/00823 
18 

data, modulation selection data, packet size selection data, a checksum, and 
extension data for any additional information. The features data notify the 
computer of the particular features of the particular remote unit in use at that time, 
such as the type of acknowledgement signal, whether a cellular phone connection 
is being used, whether the data is encrypted, and whether the acknowledgement 
from the computer to the remote unit user should occur at the end of each data 
packet transmission or at the end of all data packet transmissions (i.e., after the 
entire datastream containing the plurality of data packets has been transmitted). 
The preferred acknowledgement signal may be generated after the entire 
datastream has been transferred, as described above. The error correction data 
specifies the type of forward error correction being used for the data transmission. 
The packet size data permits the size of the data packets (i.e., the number of bytes 
between acknowledgement signals) to be varied between 1 byte and 256 bytes. 
The checksum data is transmitted in the preamble to enable the computer verify 
the integrity of the data in the preamble. 

The remote unit may also permit the user to select one of several transfer 
modes before the data is transferred from the remote unit to the computer. The 
changes in the user selectable transfer mode may effect changes in the values of 
the data sent within the preamble, including the type of forward error correction 
being used, the type of modulation being used, and the number of times that data 
will be resent. The user selectable transfer mode may allow the user to choose 
between a cellular mode, a payphone mode (a payphone typically has more noise 
problems than a normal telephone line), and a normal telephone line mode. Each 
of these user selectable modes configures the transfer protocol differently to 
optimize the remote unit's transmission for each particular environment. For 
example, for a cellular connection, which is generally extremely noisy and hard to 
communicate over, the amount of forward error correction may be increased, the 
modulation may be changed, and the number of times data may be resent is 
increased. Thus, a user is able to select a transfer protocol that is optimized for a 
particular type of first communications link, and the remote unit may provide data 
formatted in .that optimized transfer protocol to the computer. 



SUBSTITUTE SHEET (RULE 26) 



WO 97/26709 PCT7US97/00823 
19 

Once the preamble is received and the computer has configured itself to 
receive data formatted in accordance with the user selectable transfer protocol, the 
remote unit transfers the data containing the various electronic messages and 
forward error corrected electronic messages in the transmit phase 266. Once the 
transmission of the data is complete, the computer checks all of the data packets 
within the data for errors, as described below. 

In the acknowledgement phase 268, the computer transmits an 
acknowledgement signal that may either inform the user that the data was received 
without uncorrectable errors or inform the user that the data must be resent due to 
errors within the data packets. Once the data has been correctly received, the 
computer generates a closing message to the user, during the end phase 270, and 
closes the phone connection with the user and the remote unit. 

The transfer protocol provides a system wherein the user of the remote unit 
may select a different transfer protocol, depending on the communications link to 
be used, in order to optimize the transfer, as described above. The transfer 
protocol may also permit the user to receive an audible acknowledgement signal 
from the computer. This acknowledgement signal enables the user to know that 
the data has been received without errors or must be resent immediately after the 
data transmission so the user can resend the data without having to reestablish 
another connection through the first communications link. A preferred error 
detection and correction scheme will be described below, but many different error 
detection and correction schemes, such as a checksum scheme, may be used in 
the encoding of data to be sent by the remote unit system. 

Figure 1 1 is a flowchart showing the error detection and correction method 
used in the electronic messaging system of the present invention. The error 
correction method of the present invention is carried out within the incoming 
message system 76 shown in Figure 2. The encoding of the datastream (the data 
uploaded from the remote unit to the computer via the incoming message system 
and its modems) using the error correction method of the present invention takes 
place within the remote unit. At 300, the error correction method, that may include 



SUBSTITUTE SHEET (RULE 26) 



WO 97/26709 PCT/US97/00823 
20 

a Bose, Chaughuri, Hocquenghem (BCH) forward error correction system, 
message resending, and error packet overlay error correction begins. At 302, the 
incoming message system receives the error correction encoded datastream from 
the remote unit. 

The datastream from the remote unit is first encoded by the CPU in the 
remote unit using a forward error correction method, such as a (15,7,2) BCH 
information code. With this BCH code, the original data from the remote unit is 
segmented into seven (7) bits, an extra parity bit is calculated (standard even/odd 
parity) and concatenated at the end of the fifteen encoded bits to generate a 
sixteen bit word that is easier for standard computer peripherals to use. The data 
is sent from the remote unit to the incoming message system sixteen (16) bits at a 
time. Thus, all data from the remote unit to the incoming message system is sent 
in sixteen (16) bit packets that include fifteen BCH code bits and one (1) parity bit. 
The fifteen BCH code bits contain seven (7) actual data bits and eight (8) BCH 
generated code bits. This BCH code can detect and correct up two (2) random 
errors within each sixteen bit data packet. In addition, the BCH error correction 
system can also detect more than two errors per packet, but cannot correct for 
them. In practice, up to four (4) sequential bit errors in a datastream can be 
corrected if those errors are equally split between two packets (i.e., if two errors 
occur at the end of packet N and two errors occur at the beginning of packet 
N+1). 

At 304, the incoming message system determines if any BCH errors 
occurred within each packet. If there were no errors within any of the sixteen bit 
packets sent from the remote unit, then the error correction method is completed 
at 306. Similarly, if a packet had two or fewer BCH errors, then the BCH error 
correction method can correct for those errors at 308 and the method is completed 
at 310. If any data packet had more than two bit errors, the BCH error correction 
method detects the errors, and the incoming message system will request, through 
an audible tone or a voice message, that the remote unit user resend the data at 
312. 



SUBSTITUTE SHEET (RULE 26) 



WO 97/26709 PCT/US97/00823 
21 

After the data is resent at 312, the incoming message system determines if 
any errors are present within any data packet in step 314. If 0, 1, or 2 errors exist 
within a data packet of the resent datastream, then the error correction ends at 
316. An error packet overlay correction, at 318, may be used, if errors still exist in 
any of the data packets. The error packet overlay error correction method will be 
described more fully below with reference to Fig. 12. At 320, it is determined 
whether any errors still remain after the error packet overlay correction. If all errors 
have been corrected by the error packet overlay correction, then the method ends 
at 322. If uncorrectable errors still exist within any data packet after the error 
packet overlay correction, then in step 324, it is determined whether the data has 
been sent more than three times, if the data has been sent less than three times, 
then the process returns to 312 where the data is sent again and error packet 
overlay correction is conducted. If the data has been sent three or more times, 
then at 326, a majority bit vote by packet correction method, described in more 
detail below with reference to Fig. 13, may be invoked. At 328, it is determined 
whether or not any errors remain after the majority bit vote by packet has been 
completed. If no errors are present, then the method ends at 330. If errors are still 
present after the majority bit vote by packet, then the process returns to 312 in 
which data is resent. In operation, the error correction method of the present 
invention provides three separate levels of error correction that ensure that an 
error-free datastream is received by the incoming message system. 

Fig. 12 is a schematic diagram showing the error packet overlay error 
correction method. As a datastream is received by the incoming message system, 
each 16 bit BCH packet has an integrity flag attached to ft by the incoming 
message system that identifies the packet as a good packet (errors less than or 
equal to two) or as a bad packet (errors greater than two). If there is at least one 
bad packet in the datastream, then the entire datastream is resent. As provided 
above, the datastream may be resent up to N times yielding N datastreams 
(datastream J. datastream_2, and so forth; up to datastream_N) that are stored 
temporarily. As shown, the integrity flags for each packet are also stored along 
with each individual data packet. A temp_buffer memory 352 is used to store the 
results of the error packet overlay error correction method set forth in Fig. 13. In 



SUBSTITUTE SHEET (RULE 26) 



WO 97/26709 PCT/US97/00823 
22 

the example shown in Figure 12, for packet A. the packet from datastream_l is 
stored in the temporary buffer because it has a good integrity flag. Similarly, for 
packet A+ 1 , the packet from datastream_2 or datastream_N may be stored in the 
temporary buffer because both have good integrity flags. For packet A +2, since 
all of the datastreams have bad integrity flags, the majority bit vote by packet error 
correction method is conducted. Finally, for packet A +3, any once of the packets 
from the three datastreams may be used because all of the integrity flags are 
good. 



Fig. 13 is a flowchart showing the operation of the error packet overlay erro 
correction method and when the majority bit voting error correction method is 
conducted. The method begins at 360. At 362, the integrity flags (flagl , 
flag2,...flagM) of a particular data packet (1,2,...M) for each datastream are 
compared to each other. For example, as shown in Fig 12, for data packet A, the 
integrity flag (flagl) of datastreamj is good, the integrity flag (flag2) of 
datastream_2 is bad and the integrity flag (flagM) of datastream_N is bad. At 364. 
it is determined whether or not all of the integrity flags are good. At 366, if all of 
the integrity flags for a particular data packet are good, then the data packet with 
the fewest errors is stored within the temp_buffer memory 352. At 368, it is 
determined if all of the integrity flags are bad. If all of the integrity flags are bad, 
then at 370, a majority bit vote by packet is done as long as at least three 
datastreams are present. If the integrity flags are not all bad, then the packet with 
the fewest errors is selected at 366. 



Figure 14 is a schematic diagram of the majority bit vote by packet method 
that is part of the error detection and correction method shown in Figure 1 1 Each 
bit within the data packet is chosen to match the majority (more than fifty percent) 
of the bits being compared (i.e., the chosen value is the same as the value of 2 out 
of 3 bits that are compared). For example, as shown in Fig. 14, bit_one 400 in 
each datastream is 1,1, ..0 respectively for each datastream such that the majority 
(more than fifty percent) of the bits are equal to "1". Accordingly, bit_one is set to 
"1". Once the new packet values are determined by the majority bit method, the 
newly assembled data packets are checked for errors using a conventional 



SUBSTITUTE SHEET (RULE 26) 



WO 97/26709 PCT/US97/O0823 
23 

checksum method and the BCH method and are then stored in the temp_buffer 
memory, in this manner, all of the data packets within the datastream are 
determined so that the datastream can then be processed by the incoming 
message system. 

Thus, using this multi-level error detection and correction system in 
accordance with the invention, the data transmitted from the remote unit to the 
computer will be substantially error free. For most transmissions, the data may 
need only to be resent once and the error packet overlay method will detect and 
correct any errors in the data. This multi-level error detection and correction 
system increases message transmission reliability. In addition, this error correction 
and detection system is fast so that the user will very quickly receive an 
acknowledgement signal. This quick error detection and correction allows the user 
and remote unit to stay connected to the computer as short amount of time as 
possible without sacrificing message transmission integrity. 

While the foregoing has been with reference to a particular embodiment of 
the invention, it will be appreciated by those skilled in the art that changes in this 
embodiment may be made without departing from the principles and spirit of the 
invention, the scope of which is defined by the appended claims. 



SUBSTITUTE SHEET (RULE 26) 



WO 97/26709 24 PCT/US97/00823 

WE CLAIM: 

1 . A system for communicating data between a computer and a unit 
remote from the computer, comprising means in the remote unit for receiving input 
information from a user and for producing data signals corresponding to the input 
information; means for producing error corrected message signals from the data 
signals; means for generating acoustical tones corresponding to the error 
corrected message signals; means for coupling the acoustical tones to a first 
communications link for unidirectional transmission to the computer; and a 
receiving means in the remote unit for unidirectionally receiving data from the 
computer over a second communications link, which is independent of the first 
communications link. 

2. The system of Claim 1 , further comprising first receiving means in the 
remote unit for receiving a signal, over the first communications link, from the 
computer to the user to acknowledge receipt of the acoustical tones. 

3. The system of Claim 1 , wherein the error corrected message 
producing means comprises means for generating forward error correction data. 

4. The system of Claim 1 , wherein the remote unit further comprises 
means for generating facsimile, electronic mail and pager messages. 

5. The system of Claim 1 , wherein the first communications link 
comprises a telephone link. 

6. The system of Claim 1 . wherein the second communications link 
comprises a wireless link, and the means for receiving data from the second 
communications link comprises a radio pager receiver. 

7. The system of Claim 1 , wherein the acknowledgement signal is an 
audible signal generated by the computer and sent over the first communications 
link to the user of the remote unit. 



SUBSTITUTE SHEET (RULE 26) 



WO 97/26709 PCT/US97/00823 
25 

8. The system of Claim 1 , wherein the computer further comprises 
means for detecting and correcting errors in the error corrected message signals. 

9. The system of Claim 8, wherein the means for detecting and 
correcting errors comprises sending data packets from the remote unit to the 
computer, the data packets each comprising a plurality of bits; checking the data 
packets for errors in the computer; communicating to the user of the remote unit 
from the computer to resend all data packets when errors are present in any data 
packet; comparing the first-sent data packets to corresponding ones of the resent 
data packets to determine the presence of errors; and comparing corresponding 
bits of each first-sent data packet and each resent data packet to select a bit value 
that is present in a more than half of the data packets. 

1 0. A method for communicating data between a computer and a unit 
remote from the computer, comprising: 

receiving input information from a user to the remote unit; 
generating data signals in the remote unit corresponding to the input 
information; 

producing error corrected message signals in the remote unit corresponding 
to the data signals; 

generating acoustical tones in the remote unit corresponding to the error 
corrected message signals; 

transmitting the acoustical tones to the computer by coupling the acoustical 
tones to a send-only first communications link between the computer and the 
remote unit; and 

receiving, in a receiving unit of the remote unit, data from the computer over 
a receive-only second communications link, which is independent of the first 
communications link. 



11. The method of Claim 10, further comprising receiving, in a second 
receiving unit of the remote unit, a signal over the first communications link from 
the computer acknowledging receipt of the acoustical tones. 



SUBSTITUTE SHEET (RULE 26) 



WO 97/26709 



26 



PCIYUS97/00823 



12. The method of Claim 10, wherein producing error corrected message 
signals comprises generating forward error corrected data by encoding the data 
signals. 

13. The method of Claim 10, wherein coupling the acoustical tones to the 
first communications link comprises generating the acoustical tones over a speaker 
on the remote unit that is held near an input device attached to the first 
communications link. 

14. The method of Claim 10, wherein receiving the acknowledgement 
signal comprises receiving a message indicating that the data transmission is 
successful. 

1 5. The method of Claim 1 0, wherein receiving the acknowledgement 
signal comprises receiving a request to resend the data. 

1 6. The method of Claim 10, further comprising detecting and correcting 
errors in the error corrected message signals from the remote unit. 

17. The method of Claim 16, wherein the detecting and correcting errors 
comprises sending data packets from the remote unit to the computer, the data 
packets each comprising a plurality of bits; checking the data packets for errors in 
the computer; communicating to the user of the remote unit from the computer to 
resend all data packets when errors are present in any data packet; comparing the 
first-sent data packets to the corresponding resent data packets to determine the 
presence of errors; and comparing corresponding bits of each first-sent data 
packet and each resent data packet to select a bit value that is present in a more 
than half of the data packets. 

18. A method for communicating data between a computer and a unit 
remote from the computer, comprising: 

sending data packets from the remote unit to the computer, the data 



SUBSTITUTE SHEET (RULE 26) 



WO 97/26709 PCT/US97/00823 
27 

packets each comprising a plurality of bits; 

checking the data packets for errors in the computer; 

communicating to the user of the remote unit from the computer to resend 
all data packets when errors are present in any data packet; 

comparing the first-sent data packets to corresponding ones of the resent 
data packets to determine the presence of errors; and 

comparing corresponding bits of each first-sent data packet and each resent 
data packet to select a bit value that is present in a more than half of the data 
packets. 



19. The method of Claim 18, wherein checking the data packets 
comprises generating an integrity flag, for the data packets, that indicates errors 
within the data packets, wherein a good integrity flag indicates no errors, and a 
bad integrity flag indicates errors, and checking the integrity flags of the data 
packets. 



20. The method of Claim 18, wherein the communicating from the 
computer to the remote unit further comprises sending a signal from the computer 
back to the user of the remote unit indicating a successful transmission. 

21. The method of Claim 19, wherein comparing the data packets 
comprises comparing the integrity flags of the data packets to each other. 

22. For use in a system for communicating data between a computer and 
a unit remote to the computer, the remote unit comprising means for receiving 
input information from a user and for producing data signals corresponding to the 
input information; means for producing error corrected message signals from the 
data signals; means for generating acoustical tones corresponding to the error 
corrected message signals; means for coupling the acoustical tones to a send-only 
first communications link for transmission to the computer; first receiving means for 
receiving a signal, over the first communications link, from the computer to the user 
of the remote unit to acknowledge receipt of the acoustical tones; and a second 
receiving means for receiving data from the computer over a send-only second 



SUBSTITUTE SHEET (RULE 26) 



WO 97/26709 



PCT/US97/00823 



28 

communications link, which is independent of the first communications link. 



SUBSTITUTE SHEET (RULE 26) 



WO 97/26709 



PCT/US97/00823 



1/12 



22- 




E-mail Output V 32 



Pager Output h 34 



FIG. 1 



WO 97/26709 



PCT/US97/00823 



2/12 



o 




WO 97/26709 



PCT/US97/00823 



3/12 




-108 



22- 

FIG.4 



22. 



106 



FIG. 5 



i n i-i n n r-i r-i >-i r^n 

r ^? 

22 26 

FIG. 6 



WO 97/26709 



PCT/US97/00823 



4/12 




WO 97/26709 



PCT/US97/0O823 



5/12 





WO 97/26709 



PCT/US97/00823 



6/12 



Answer Telephone p~ 220 



Play Voice Message Telling User to send 
Data 



Receive Outgoing Message Data. New 
E-mail Screening Criteria, and Log of 
Messages Reserved Since Last 
Communication with Network 
Gateway from Subscriber Handheld 
Unit 



-222 



-224 



FIG. 9A 




Verbally Tell Subscriber 
Message was Received Clearly 



Hang Up Telephone } — ^30 



Divide Incoming data into E-mail 
Screening Criteria Changes, Incoming 

Messages, and Log of Messages 
Received by Subscriber Handheld 
Unit Recently. 



—232 



Analy2e Log of Messages received by 
Subscriber Handheld Unit 



-234 



WO 97/26709 



PCT/US97/00823 



7/12 




^238 

f\ _ocate Missing Paging Messages 
in Database and Upload to 
Paging Terminal for Transmission 
to Subscriber Handheld Unit 
(see Outgoing Pager 
Messaging Server) J 



Forward Changes in E-mail Screening 
Criteria to Customer Record Database 



242- 



Forward Outgoing Messages To 
Outgoing Message Stack 



244 



Control 
transfej 




End , 



FIG. 9B 



FIG.9A 



FIG. 9B 



FIG. 9 



WO 97/26709 



PCT/US97/00823 



8/12 



Remote Unit 



260 

v. 

262 

264 

Sequence 
Phase 
266 -S*> 



V 



270 



Dial 



Connect 



Preamble 



Transmit 



Acknowledgement 



End 



Remote Unit Dials in 



^ ^mputer Greeting 
Remote Unit Preamble 



Remote Unit Transmission 

o 

Computer Acknowledge 



Comp uter Clo sing Message 



Computer 



FIG. 10 



WO 97/26709 



PCT/US97/00823 




FIG. 11 



WO 97/26709 



PCT/US97/00823 



10/12 



DataStreamJ 



DataStream_2 



352 



Packet a 


Packet A+1 


Jacket A+2 


3 acket A+3 


tntegrity:G 


lntegrity:B 


ntegrity:B 


ntegrity:G 


Packet A 


3 acketA+1 


Packet A+2 


3 ackelA±l 


lntegrity:B 


ntegrity:G 


ntegrity:B 


ntegrity:G 


Packet A 


Packet A+1 


3 acketA+2 


3 acketA + 3 


tntegrity:B 


ntegrity:G 


ntegrity:B 


ntegrity:G 


Q Q Q Q 


Packet A 


Packet A+1 


Majority 
bit vote 


3 acket A+3 



FIG. 12 



WO 97/26709 



PCT/TJS97/00823 




FIG. 13 



WO 97/26709 



PCT/US97/00823 



12/12 



Bit Stream #1 1 1 1 1 \ 0 [ 1 1 1 1 1 1 I I I I I | | j | [ 

Bit Stream #2 1 1 1 0| Ol 0| 1 1 1 1 I I I I I I I I I | 

Bit Stream #N 1 1 1 0 f 1 i 1 1 0 1 1 1 I I I I I I [ [ j | 

Temporary Buffer j 1 1 0 1 0 1 1 1 1 1 1 1 I M I I I j j | 1 
400^ 

FIG. 14 



INTERNATIONAL SEARCH REPORT 



International application No 
PCT/US97/00823 



A. CLASSIFICATION OF SUBJECT MATTER 
IPC(6) :H03M 13/00; H04L 1/18; H04M 11/00 
US CL :371/33, 35, 62, 379/58, 100 

According to International Patent Classification (IPC) or 

B. FIELDS SEARCHED 



■ both national classifies 



i documentation learched (classification system followed by classification symbols) 
U.S. : 371/33. 35. 62; 379/56, 57, 58, 100; 358/405, 406, 440. 442, 468; 370/448, 479. 375/206 ; 455/53.1, 54.1 



Documentation searched other than minimum documentation to the extent that such documents are included in the fields si 



Electronic data base consulted during the ir 
MAYA 



* base and, where practicable, search terms used) 



C. DOCUMENTS CONSIDERED TO BE RELEVANT 



Y, P 

Y, P 

A 
A 



Citation of document, with indication, where appropriate, of the relevant passages 



US 5,588,009 A (WILL) 24 December 1996, column 5, lines 
8-34. 

US 5,509,050 A (BERLAND) 16 April 1996, column 6, lines 
30-52. 

US 5,142,550 A (TYMES) 25 August 1992, see abstract. 

US 4,584,679 A (LIVINGSTON ET AL.) 22 April 1986, 
column 2, lines 47-62. 



Relevant to claim No 



1-22 

1-22 

1-22 
1-22 



U Further documents are listed m the conunuauon of Box C. \J See patent famuy annex 


SfepnomyriMcciuacd *" *~*-*mt member of the mmc fWv 


Date of the actual completion of the international search 
26 MARCH 1997 


Date of mailing of the international search report ~" 1 

2 3 APR 1997 


Name and mailing address of the ISA/US 
Commmiooer of Patents and Trademarks 

Washington, D.C. 20231 
Facsimile No. (703) 305-3230 

Form PCT/ISA/210 (second sheetXJulv 1992)* ~ 


^Authorized officer 

EMMANUEL L. MOISE 
iVlephone No. (703) 305-9706