Method and apparatus for selecting a communication mode in a mobile communication device having voice recognition capability

A mobile communication device containing voice recognition capability is first enabled to perform voice recognition (102). The user then speaks the name of the party the user wishes to call (104), the name corresponding to a record the user has programmed into a memory of the mobile communication device. The mobile communication device then uses the output (106) of the voice recognition process to search the memory for a corresponding record (108). The record contains at least two calling numbers, each associated with a different mode of communication, such as dispatch and telephone communication. For a brief period of time after locating the record, the mobile communication device waits (118) for the user to initiate a call in the first communication mode (120) by, for example, pressing a dispatch call button (124). If, after a preselected duration of time has passed and no input is received from the user, the mobile communication device defaults to a second communication mode and makes a call (122).

TECHNICAL FIELD 
This invention relates in general to mobile communication devices, and more 
particularly to mobile communication device that are capable of engaging 
in more than one type of communication service. 
BACKGROUND OF THE INVENTION 
Mobile communications has evolved from an expensive service, used by 
relatively few people, to a commonly used and affordable service. Many 
people consider their mobile communications service as indispensable as 
land line telephone service. With the proliferation of mobile 
communication systems, there has been a demand for additional services 
besides mobile telephone service. Recently some service providers and 
system operators have begun to offer dispatch service in addition to 
telephone service, both types of service being supported by a single 
mobile communications device. Dispatch service is essentially a half 
duplex communication mode where users take turns speaking, similar to two 
way radio communication except the signal is carried over a land based 
network instead of directly from radio to radio. Just as each mobile 
communication device has an associated telephone number, so does it have 
an associated dispatch identification number. 
It is also true that manufactures are designing more features into mobile 
communication devices. One feature that is gaining popularity is voice 
recognition for selecting a record from a memory of the mobile 
communication device. Typically a user stores the name and phone number of 
another party, or may have the number stored in one of a few speed call 
memory locations. When the user desires to call another party for which 
there is a record stored in the mobile communication device, the use 
activates voice recognition and speaks the party's name. The voice 
recognition algorithms maps the audio voice signal to, for example, a 
record identifier such as text, and uses this to locate a corresponding 
record in the memory. When the record is located, the associated phone 
number is retrieved and either the number is automatically dialed, or 
displayed so that the user can simply confirm it is the desired record. 
Voice recognition is a relatively processor intensive operation. For a hand 
held, battery operated communication device, it is preferable to minimize 
the amount of processing done in completing tasks. There are numerous 
methods and algorithms for performing voice recognition, many of which, 
while powerful and typically are highly accurate, would require far more 
computing resources than is typically available in a cost sensitive 
product such as a mobile communication device. Therefore, the voice 
recognition techniques used are generally less accurate than higher 
accuracy versions used in, for example, desktop personal computers. 
Therefore, it is preferable if, in a mobile communication device, the 
voice recognition based record retrieval can be performed with the 
utterance of a single word. In communication devices that support only one 
mode of communication, i.e. telephone interconnect, only the name or speed 
dial number of the desired record needs to be uttered by the user. This 
limits the amount of processing that is necessary, and therefore allows 
the use of a less powerful voice recognition method. 
However, in a mobile communication devices that support more than one type 
of communications modes, such as mobile telephony and dispatch calling, 
each record will typically have two numbers associated with it; one for a 
first mode of communication, such as dispatch or private dispatch calling, 
and a second number associated with a second mode of communication, such 
as mobile telephony. In employing voice recognition, the voice recognition 
would have to be given an indicator as to which communication mode is 
desired so that the appropriate number can be retrieved. This can be done 
by speaking the type of service in addition to the name of the party the 
user wishes to call. However, a two-word utterance is less likely to be 
accurately recognized; if a single word has a 90% probability of being 
recognized, two words together have only an 81% likelihood of being 
properly recognized (90% for each word). Therefore there is a need for 
performing voice recognition based record retrieval in a mobile 
communication device having more than one more of communication, without 
increasing the amount of voice information that needs to be processed.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
While the specification concludes with claims defining the features of the 
invention that are regarded as novel, it is believed that the invention 
will be better understood from a consideration of the following 
description in conjunction with the drawing figures, in which like 
reference numerals are carried forward. 
The invention permits a default communication mode to be set. Upon enabling 
a voice recognition mode in the mobile communication device, the user 
speaks a single word corresponding to the desired record, such as the name 
of the party to be called. The mobile communication device will then 
correlate the received audio voice information with a record and 
initialize the mobile communication device to make a call associated with 
a first calling number, such as a dispatch call, whereupon the user will, 
for example, press a dispatch call button to make the dispatch call. 
However, if no input is received within a preselected period of time, the 
mobile communication device defaults to a second mode of communication, 
and uses a second calling number associated with the record to make a 
corresponding type of call, such as a telephone call. Preferably, the 
second type of call is made automatically, without user input after the 
time has expired. 
Referring now to FIG. 1, there is shown a flow chart diagram of a method 
for selecting a communication mode in a mobile communication device having 
voice recognition capability. At the start (100) the mobile communication 
device is powered-up, and registered for service with a communication 
service provider. The start up step includes the step of providing a 
communication device that is capable of making calls in at least two 
communication modes, such as dispatch or telephone. By dispatch it is 
meant a half-duplex type of communication, similar in effect to two-way 
radio communication. An example of such a mobile communication device 
would be any one of the mobile communication devices sold by Motorola, 
Inc. under the trade name iDEN. Upon the user of the mobile communication 
device deciding to make a call, the user enables (102) a voice recognition 
mode of the mobile communication device. Since performing voice 
recognition requires processor operations, it is best to leave it off when 
not in use to conserve battery energy. Upon enabling voice recognition, 
the mobile communication device will preferably provide an indication that 
voice recognition is enabled, queuing the user to begin speaking (104). 
The mobile communication device receives (106) the audio voice input, and 
begins processing it in accordance with known voice recognition 
techniques. Generally, the voice recognition process will map the audio 
voice input to a means of identifying a record that is easily manipulated 
by a digital processor, such as ASCII text. The mobile communication 
device then correlates the output with a record stored in a memory of the 
mobile communication device by searching (108) through the records stored 
therein for a match. If no match is found (110), the mobile communication 
device will prompt (112) the user to try again. If a match is found, the 
record is retrieved, and an indication is given to the user by, for 
example, displaying (114) the record information on a display of the 
mobile communication device. Preferably the mobile communication device 
will give the user an opportunity to reject (116) the record if it is not 
the desired record. Upon successfully locating a matching record, the 
mobile communication device starts a timer (118). The timer is set to 
expire after a preselected period of time, such as 5 seconds, for example. 
During the time the timer is not expired, the mobile communication device 
is initialized to make a call using a first communication mode, such as a 
dispatch mode. While so initialized, the mobile communication device 
checks (120) to see if the user has provided an affirmative indication 
that the first communication mode is the desired mode, such as by pressing 
a dispatch call button located on the mobile communication device. If so, 
then a call is immediately made using the first communication mode. 
However, if no input is received, and the timer expires, then the mobile 
communication device initializes itself to make a call using a second 
communication mode, and preferably automatically make a call using a 
second calling number of the retrieved record. For example, if the timer 
expires, the mobile communication device will load a telephone number from 
the retrieved record, and make a telephone call. This obviates the need to 
for the user to speak two words, such as the name of the party and the 
type of call desired to be made to the party. While the timer is running, 
and while no affirmative input is received from the user, it is preferred 
that the user may also cancel the action. 
Referring now to FIG. 2, there is shown a block diagram schematic of one 
embodiment of a mobile communication device, in accordance with the 
invention. The mobile communication device comprises an audio input 
processing means 200, including a transducer such as a microphone 202 and 
preferably audio filtering and amplification circuitry 204. The audio 
input processing means provides an output signal to a voice recognition 
means 206, including, for example, a digital signal processor 208 (DSP) 
and instruction code stored in an associated memory means 210 for 
performing voice recognition algorithms. Upon processing a received audio 
voice input signal, the voice recognition means produces an output, as 
described hereinabove. The voice recognition means may pass this output to 
controller means 212 for searching, or it is contemplated that the voice 
recognition means may perform the search itself equivalently. Preferably, 
the mobile communication device comprises the controller means to control 
other functions in the mobile communication device, such as input and 
output, control of the radio frequency hardware, and so on. The controller 
means includes a microprocessor or microcontroller 214 and instruction 
code stored in a controller memory 216. The mobile communication device 
also comprises a semi-permanent memory 218 for storing records. Preferably 
each record contains an alias field, such as the name of the party, a 
first communication mode calling number field, and a second communication 
mode calling number field. The controller means constitutes a monitoring 
means for monitoring an input device, such as a keypad and other buttons 
220. The controller memory contains instructions for performing, among 
other, steps 108-124 of FIG. 1. Once the type of call to be made is 
determined, either by the user selecting the first communication mode by 
asserting an input, or defaulting to the second communication mode, the 
controller means directs various parts of the mobile communication device 
to make the desired type of call. This includes controlling a radio 
frequency means 222 to communicate with a communication system over an air 
interface, and establish the desired call type. 
Thus, the present invention allows for one word voice recognition in a 
mobile communication device having a plurality of communication modes. The 
method comprises enabling voice recognition; receiving an audio voice 
input from the user of the mobile communication device; searching a local 
memory and correlating the output of the voice recognition process with a 
record, the record having at least two calling numbers, each associated 
with a different type of communication mode, then waiting for a 
preselected period of time. If the user presents an input to the mobile 
communication device during the preselected time, the mobile communication 
device makes a call using a first mode of communication. If, however, the 
preselected period of time expires before any input is received from the 
user, a call using the second mode of communication is made. 
While the preferred embodiments of the invention have been illustrated and 
described, it will be clear that the invention is not so limited. Numerous 
modifications, changes, variations, substitutions and equivalents will 
occur to those skilled in the art without departing from the spirit and 
scope of the present invention as defined by the appended claims.