Method and device for off hour over the air software programming of selective call receivers

A selective call receiver (10) utilizes a method for performing over-the-air software programming when the selective call receiver (10) is on or switched off by a user. A first selective call signal is received and programming related information including an anticipated time of transmission of a second selective call signal is received. The selective call receiver (10) is prepared to receive the second selective call signal in response to the programming related information received, whereby the receiver circuitry (30) is energized at the anticipated time of transmission to receive the second selective call signal. The selective call receiver (10) is further switched on at the anticipated time of transmission of the second selective call signal, and the receiver circuitry (30) is energized to receive the second selective call signal when the user has switched off the selective call receiver (10) prior to the anticipated time.

FIELD OF THE INVENTION 
This invention relates generally to selective call receivers, and more 
particularly, to a system and method for automatically performing airway 
software upgrades in pagers and pager like devices at predetermined times 
for conserving battery power, increasing the probability of effectuating 
software changes and improving the efficiency of radio carriers. 
BACKGROUND OF THE INVENTION 
Selective call receivers, such as pagers, are devices for receiving 
electronic messages, also called pages or selective call signals. The 
transmitted selective call signals are sent by an originator to a portable 
target device at a predetermined address assigned to the selective call 
receiver and demodulated, decoded and processed by a processor to generate 
a user readable message displayed for viewing. The processor also accepts 
user inputs via user controls, acts upon the inputs, activates an alarm to 
alert the user/owner of incoming messages, and stores and accesses 
information and messages in nonvolatile memory. As is appreciated by those 
skilled in the art, other major components in a selective call receiver 
include radio frequency (RF) receiver circuitry for receiving and 
demodulating selective call signals and protocol information; preamble and 
sync code detection circuitry to process the protocol preamble and 
synchronization code words, respectively, by correlating a known preamble 
bit pattern with the demodulated signal and by framed synchronization with 
a periodically imported sync code to maintain synchronized communication; 
address correlating circuitry for comparing address information in the 
demodulated signal with a predetermined address of the receiver; baud rate 
detection circuitry for generating a signal that indicates the symbol or 
baud rate of the signal; internal timing controls; and nonvolatile memory 
locations for storing select information in the absence of power. 
The components selected in conventional selective call receiver circuitry 
designs are typically low energy consuming components. Low powered 
components are preferred since there exists an ongoing challenge in pager 
and portable communications technology to conserve battery power, to 
extend battery life and to minimize the size of the battery source 
required for weight and dimensional reasons. Not all of the circuitry in a 
selective call receiver can utilize low energy consumption components due 
to desired performance characteristics. For instance, the RF receiver 
circuitry still uses high energy consuming components. Accordingly, other 
methods and systems are incorporated in pager architecture to minimize 
power consumption. One such method and apparatus includes the battery 
saving circuit disclosed in U.S. Pat. No. 5,376,975, commonly assigned to 
the assignee of the present invention. Since the receiver circuit requires 
high energy consuming components and can not be continually active, the 
receiver is selectively energized to guarantee that it receives the 
synchronization word code (sync code) of a transmitted page and is 
deactivated for a predetermined amount of time while the sync code is 
processed and correlated by the selective call receiver to conserve power. 
The battery saving circuit provides a signal to a receiver circuit to 
periodically energize and deenergize the receiver circuit. The battery 
saving circuit receives periodic inputs from the processor to periodically 
activate and deactivate the receiver circuit at predetermined rates based 
on the occurrence of the events responsive to signals from the sync code 
detector, the address correlator and the baud rate detector. However, the 
receiver circuitry and battery saver can only work when the selective call 
receiver, or pager, is powered, or in the "on mode." If the selective call 
receiver is not energized, then it cannot receive any selective call 
signals and users typically power down their units during off-peak hours, 
that is between 11 p.m. and 5 a.m., to conserve valuable battery power. 
The problem associated with removing power from selective call receiver is 
that the receiver is also de-energized such that selective call signals 
cannot be received by the device. Signals received by selective call 
receivers include small, user specific messages, as well as larger signals 
for implementing programming changes and software upgrades to the 
selective call receiver. The type of programmable call receiver upgrades 
and changes being done over the air (OTA) may be found in U.S. Pat. No. 
4,839,628 to Davis, et al, issued Jun. 13, 1989 and include reprogramming 
memory (RAM, FLASH, EEPROM and the control ROM) with software upgrades; 
changing variables, memory parameters, applications and executables; 
adding data features such as real estate, sports and stock market files; 
and interrupting service to the device. The problem is that OTA changes to 
the selective call receiver device tend to be large and, as such, 
interfere with receiving personal user specific messages. In addition, the 
selective call device cannot receive required programming changes and 
upgrades unless the receiver is left activated. 
Although selective call receivers are becoming increasingly sophisticated 
in their ability to do OTA software upgrades, a major drawback still 
exists in radio carrier capacity. Pager OTA programming upgrades can be 
long and time consuming even with high speed protocols, such as POCSAG or 
FLEX, especially during high traffic times. In addition, OTA programming 
renders the device unavailable for other incoming messages and must be 
performed while the device is in the "on mode." Since peak time traffic is 
already high, doing OTA software upgrades during peak hours chokes the 
RCC's system which decreases the probability of having a successful 
upgrade and decreases the overall efficiency of controlling radio 
communication traffic. 
Consequently, OTA software upgrade programming should be done during the 
off peak hours, such as 11 p.m. to 5 a.m., so as to not interfere with 
normal air traffic and to better effectuate processing. Most selective 
call receiver devices, however, are placed in the off mode late at night 
and during the low peak hours to conserve and extend battery life. 
Therefore, implementing off peak hour software upgrades requires the 
device be "on" at all times which requires a trade off with overall 
battery life. Since conserving battery power is essential, off-peak OTA 
programming is not necessarily a viable solution. While devices such as 
battery saving circuits periodically deactivate the receiver to reduce 
energy consumption, it does not have the ability to reactivate the 
receiver circuitry for receiving OTA software upgrades when the device is 
off. In addition, coordinating device subscribers and control centers for 
processing OTA off peak hours programming does not offer a practical 
solution. Accordingly, there exists a need for a method and system for 
allowing selective call receiver devices to be automatically upgraded with 
OTA software changes when the device is in the off mode so that upgrades 
may be implemented during the off peak hours without forfeiting battery 
life. Such a system would allow users to deactivate their devices when not 
in use during the late night or low peak hours to conserve battery power, 
yet enable them to still receive OTA software upgrades. 
SUMMARY OF THE INVENTION 
Accordingly, the present invention provides a selective call receiver 
device and method for implementing OTA software upgrades in selective call 
receiver devices during predetermined times such as off-peak air 
communication hours. The instant invention is designed to allow the device 
to be placed in the power off mode and yet receive OTA software upgrades 
without user intervention. This allows the device to be turned off during 
the off-peak hours to conserve battery power and then automatically 
reactivated to receive software upgrades in a manner transparent to the 
device owner. 
In accordance with an embodiment of the present invention, a method for 
performing over-the-air software programming of a selective call receiver 
which can be switched off at any time by a user, the over-the-air software 
programming being independent of and transparent to an action by the user, 
the selective call receiver including receiver circuitry for receiving and 
demodulating selective call signals, said method comprising the steps of: 
(a) receiving a first selective call signal intended for the selective call 
receiver; 
(b) detecting, within the first selective call signal, predetermined 
programming related information which includes an anticipated time of 
transmission of a second selective call signal; 
(c) preparing the selective call receiver to receive the second selective 
call signal in response to the programming related information; 
(d) receiving the second selective call signal in response to said step of 
preparing at the anticipated time of transmission of the second selective 
call signal; and 
(e) switching the selective call receiver on at the anticipated time of 
transmission of the second selective call signal to receive the second 
selective call signal when the user has switched off the selective call 
receiver prior to the anticipated time. 
In accordance with another aspect of the present invention, a selective 
call receiver which can be switched off at any time by a user and which 
can be programmed over-the-air independent of and transparent to an action 
by a user comprises receiver circuitry, a processor, timing control means 
and energizing circuitry. The receiver circuitry receives and demodulates 
selective call signals, including a first selective call signal which 
delivers programming related information which includes an anticipated 
time of transmission of a second selective call signal. The processor is 
coupled to the receiver circuitry and for detects the anticipated time of 
transmission of the second selective call signal within the programming 
related information. The timing control means is coupled to the processor 
and is responsive to the anticipated time of transmission for generating a 
control signal in response to an occurrence of the anticipated time of 
transmission of the second selective call signal. The energizing circuitry 
selectively energizes the receiver circuitry in response to the control 
signal for enabling the receiving and demodulating of the second selective 
call signal. The energizing circuitry further switches on the selective 
call receiver and selectively energizes the receiver circuitry for 
enabling the receiving and demodulating the second selective call signal 
when the user has switched off the selective call receiver prior to the 
anticipated time.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 1-4, the selective call receiver 10 and method for OTA 
programming 100 in accordance with the present invention are depicted. The 
embodiments of the instant invention provide a selective call receiver 10 
and method 100 for receiving selective call signals, including control 
pages and OTA software upgrade programs, that automatically perform 
software program upgrades in the device. The system of the instant 
invention comprises a receiving means including a receiver circuitry 12, a 
timing means including a time correlator 26, and a nonvolatile internal 
timer 24, sync detector circuitry 18, baud rate detector or detecting 
means 14, nonvolatile memory 32, flash RAM memory 28 EEPROM, STATIC RAM 
and an address correlation means including a control page address 
correlator 20 for correlating control page address information with 
selective call receiver address information. 
In the system of the present invention, the selective call receiver 10 
receives selective call signals which includes first selective call 
signals having device programming related information, such as, the 
anticipated transmission time of the second selective call signals which 
include the actual OTA software program upgrades. Accordingly, the device 
can prepare itself to receive the program upgrade signals at the 
anticipated time without user involvement. The series of control page data 
words are transmitted via conventional radio communication carrier means 
from the signal call receiver's control center, local or otherwise, at 
different times of the day as shown in FIG. 4. The times of control page 
transmission may be predetermined and scheduled for transmission during or 
close to the peak hours of airway traffic when the selective call 
receivers are normally "on" to ensure reception. The control page 200 is 
intended to include the information required to schedule an OTA software 
program upgrade so as to utilize little overhead. That is, the control 
page 200 is designed for low overhead, limiting itself to program time, 
address information and size information, so that it does not interfere 
with the current flow of radio carrier traffic. The control page 200 can 
also hit multiple pagers with the same data by indicating codes and times 
of programming so as to prompt the pagers that will be receiving the same 
upgrades with the control page 200. Thus, the instant invention prompts at 
least one selective call receiver that an over the air software upgrade 
page 210, herein after refereed to as an OTA software upgrade page 210 
will be implemented at a predetermined time without interfering with peak 
hour traffic. Each of the control page words may be limited to a 
predetermined data size and merely include a specific data string of 
relevant information to enable the selective call receiver 10 to prepare 
for the OTA software upgrade page 210. The preferred control page 200 
includes the approximate time that the OTA software upgrade page 210 will 
begin broadcasting and may further include the approximate byte size of 
the OTA software upgrade page 210. The size of the upgrade program is 
typically referenced in bits or bytes, but may be delineated by the 
approximate time required for programming. 
With reference to FIG. 1, all selective call signals are received and 
demodulated by the receiver circuitry 12 and processed if it is of a 
compatible baud rate. Accordingly, the control page 200 and ultimately the 
OTA software upgrade page 210 transmissions are received by the selective 
call receiver 10 and filtered through the receiver circuitry 12 for 
processing. After demodulating the received selective call signal, that is 
either the control page 200 or OTA software upgrade page 210, the 
demodulated word is sent to the preamble and sync code detector 18, to the 
baud rate detector 14 and to the control page address correlator 20 to 
determine if a compatible and readable signal is present for further 
processing. The sync code and baud rate detectors comprise conventional 
circuitry for receiving, synchronizing and processing selective call 
signals from conventional synchronous, pseudo-synchronous, and 
asynchronous protocols, such as POCSAG, FLEX.TM. and other protocols. The 
control page address correlator 20 may be a conventional address 
correlator or may comprise novel features, as discussed herein, for 
receiving and accepting control pages and OTA software programs. The 
selective call receiver 10 is adaptable to any protocol because the 
control page 200 is transmitted and received by the selective call 
receiver 10 as a conventional message and demodulated to determine 
compatibility with the receiving device and to store the programming data 
information. Although the instant invention is preferably implemented with 
synchronous paging protocols, for purposes of this discussion, the instant 
invention is described with reference to the POCSAG protocol which is 
considered a pseudo-synchonous protocol. 
In the POCSAG protocol, the control page data word is preceded by a 
conventional preamble and sync protocol. Other protocols may have a 
comparable data or bit string, like the preamble, to precede message data 
strings to prepare the device for receiving messages. The preamble is 
typically a 576 bit string of one-to-zero transitions and a 32 bit 
synchronization code word ("sync code") which the device receiver uses to 
establish synchronization. The control page data word follows the preamble 
and sync code, and includes the header information and program related 
data. The header typically includes the control page address of the device 
being upgraded and the programming related data. The control page address 
is exclusive to the device and programmed by the controlling company to 
protect the device from being reprogrammed or changed without 
authorization. The control page address is compared to the address of the 
device by the control page address correlator 20 to determine 
compatibility with the device. The control page address may be a new 
individual address used exclusively for programing purposes as a password 
to protect the device or it may be an existing address. Either way it is 
only known by the device's control center which originates the control 
page and upgrade, and it is transparent to other users. 
Once the baud rate detector 14 determines that a selective call signal of 
compatible speed is being received, the baud rate detector 14 prompts the 
processor 22 which initiates control and authorizes further activity of 
the receiver circuitry 12. The processor 22 prompts the preamble and sync 
code detector circuitry 18 to begin reading the preamble code and sync 
code. The preamble and sync code detection and processing involves 
conventional circuitry and procedures wherein the preamble circuitry reads 
the demodulated signal and correlates it with a preamble bit pattern known 
to the preamble detector 20. It should be noted that the sync code 
detector 18 may comprise any conventional protocol communications matching 
circuitry known in the art, since the instant invention preferably 
provides a means for over the air software programming independent of the 
user and pager activity. Since the preamble typically comprises at least 
576 alternating zero-to-one transitions which must be correlated, a 
conventional battery saving circuit, energized by the processor 22, 
deactivates the receiver circuitry 12 while the preamble bit pattern is 
correlated to conserve battery power. Since the synchronization code word 
follows the preamble bit pattern, the sync code detector 18 is 
subsequently activated by a signal from the processor 22. The sync code 
detector 18 correlates the demodulated signal to detect the presence of 
the sync code and then stores it in nonvolatile memory 32. The sync code 
detector periodically retrieves the sync code from nonvolatile memory 32 
for processing to maintain synchronized communication. Before processing 
the actual control page message, the selective call receiver 10 must 
correlate the device address and the target address transmitted in the 
demodulated selective call signal, when either the control page 200 or OTA 
software upgrade page 210 is received. Once the central page address 
correlator 20 receives a start signal from the processor 22, it correlates 
the address information from the demodulated signal with a predetermined 
address assigned to the selective call receiver 10 and stored in 
nonvolatile memory 32. The predetermined address identifies the selective 
call receiver 10. Again, the correlation of the stored assigned address 
and the target address may be conventional. The purpose of the control 
page address correlator 20 is to match the address of the selective call 
receiver 10 with the selective call signal addresses in the control pages 
and messages to protect the device from unauthorized or improperly 
executed software changes. Thus, in addition to conventional address 
correlators which provide a confirming signal to the processor, the 
control page address correlator 20 of the instant invention provides a 
signal to the processor 22 once the control page or OTA upgrade address 
information is processed indicating whether to receive, process and allow 
scheduled OTA upgrade or programming pages. 
If a proper address correlation is achieved the control page 200 and OTA 
software upgrade page 210 information will be stored in memory 28. The 
control page information is saved so that it may be retrieved by the time 
correlator 26 which compares the program time with a timing signal from 
nonvolatile internal timer 24 and generates a control signal for 
transmission to the processor when proper time correlation is achieved. 
The processor 22 then provides an activation signal to the receiver strobe 
circuitry 30 which energizes the receiver circuitry 12 in time to receive 
the OTA software update page 210. The OTA software upgrade page 210 is 
also stored in memory nonvolatile 32 for programming. The processing of 
the control page 200 and upgrade 40 is preceded by the processing of the 
decoder 16 which decodes the demodulated signal and provides the decoded 
signal information to the processor 22, as conventionally known. It should 
be noted that the control page may also be stored in an EEPROM location. 
In accordance with conventional selective call receiver architecture, the 
receiver circuitry 12 may sleep while the selective call signal 
information, including control page time, preamble detection, address, and 
baud rate information is processed and correlated with the selective call 
receiver 10 prior to being reactivated. Conventional receiver strobe 
circuitry 30, or battery saving circuitry, provides a signal to the 
receiver circuitry 12 to energize or de-energize the receiver circuitry 12 
for conserving battery power and extending battery life. The processor 22 
provides an energization signal to the receiver strobe circuitry 30 at a 
preselect time after the sync code is still being processed, affording the 
receiver circuitry 12 warm-up time. The processor 22 also provides a 
signal to the receiver strobe circuitry 30 to deactivate the receiver 
circuitry 12 in response to signals from the sync code detector 18, the 
control page, the control page address correlator 20, and the baud rate 
detector 14. 
Accordingly, the scope of the instant invention contemplates receiving two 
distinct but interrelated messages, the control page 200 and the OTA 
software upgrade page 210. The receiver circuitry 12 receives a control 
page word 200 for prompting the selective call receiver 10 that an OTA 
software upgrade, will be implemented at a predetermined time, preferably 
during off peak hours. The user may also be prompted if an upgrade is to 
be performed by the selective call receiver 10 with an audible or visible 
prompt to warn the user. Like other incoming messages, the control page 
200 has a message that is preceded by a preamble and sync code, or similar 
protocol patterns which must be processed and correlated. Upon receiving, 
demodulating and accepting the control page 200 for processing, the 
control page message is decoded by the decoder 16 which provides the 
selective call signal information to the processor. The control page 
message is like any typical message transmitted to a user. A distinction, 
however, is that this message is intended for the actual device and is 
transparent to the user. Thus, it is not placed in user readable format. 
The control page 200 includes information which provides relevant times of 
when an OTA upgrade will occur and may also include the anticipated size 
of the new code being implemented. Providing the OTA program size may aid 
the device in determining whether the complete OTA upgrade is received 
based on a predetermined margin of error. The time and new code size data 
information may be stored in flash RAM 28, RAM, or EEPROM in the processor 
22 and extracted for preparing the device for programming. According to 
the instant invention, a nonvolatile internal timer 24 maintains a 
relevant time compatible with the scheduled upgrade time so that the 
selective call receiver can be prepared to receive the new code at the 
appropriate time. 
The instant invention also includes a time correlator 26 which compares the 
OTA software upgrade programming time with an actual time from the 
nonvolatile internal timer 24 for anticipating the OTA upgrade. The 
compared times are typically in the form of signals provided by the 
processor 22 and nonvolatile internal timer 24. Upon receiving the program 
time, the processor 22 provides a signal to the time correlator 26 
indicating the time of OTA upgrade. The time correlator 26 may store this 
time for correlating with the actual timer time or it may continually 
extrapolate the scheduled time from flash RAM or EEPROM. The time 
correlator 26 may also have a pointer or indexing means for overriding and 
replacing the scheduled time with a new time. In any event, the time 
correlator 26 correlates stored upgrade time with the actual time provided 
by the nonvolatile internal timer 24 until the times match. Once the times 
correlate, the time correlator 26 provides a signal to the processor 22 
prompting the processor 22 to initiate power to the selective call 
receiver 10 if not already "on" and to energize the receiver circuitry 12. 
The processor 22 then provides an energization signal to a power circuit 
not shown and then to the receiver strobe circuitry 30 to activate the 
receiver circuitry 12. Thereafter, the receiver circuitry 12 sniffs the 
air looking for the anticipated OTA upgrade message until it is received, 
demodulated and correlated as previously discussed and shown in FIG. 4. If 
the OTA new code is received and decoded, it is stored in the memory 28 by 
the processor 22. The memory 28 is a temporary nonvolatile RAM location 
for storing the new code. Once the new code is received and stored the 
processor implements the OTA software upgrade into memory at the 
designated location as indicated by the OTA message. 
As noted, the selective code receiver device includes a nonvolatile 
internal timer 24. A time signal is generated by the timer and provided to 
the time correlator 26. The time correlator 26 compares the time signal to 
the scheduled programming time. When the two times match the pager is 
prepared for programming. As aforementioned, a signal is provided by the 
time correlator 26 to the processor 22 which signals the receiver strobe 
circuitry 30 to provide a signal to activate the receiver circuitry 12. 
After warm-up, the receiver circuitry 12 sniffs the air for a 
predetermined or allotted time looking for the OTA software upgrade 
message 210. The amount of time a selective call receiver 10 looks for an 
OTA software upgrade may be preprogrammed into the device, or determined 
by the control page 200. The time correlator 26 keeps track of time spent 
looking for the OTA software upgrade and will send a sniff termination 
signal to the processor 22 when the allotted time has elapsed. 
A successful transmission and receipt of the control page 200 may be 
authenticated to confirm that the complete control page data string has 
been received by the selective call receiver 10. For instance, with two 
way communications capability, a conventional handshake procedure can be 
used to confirm. In an alternative embodiment, the control page word may 
include information at the ends of the data string indicating the size of 
the control page 200. This information can be appropriately used by the 
select call receiver 10 to determine whether a complete OTA software 
upgrade page 210 is received before saving the program. The same may be 
done for the control page 200. If the complete control page 200 is not 
received, the selective call receiver 10 may remain activated until the 
next control page pulse is completely received and stored. The transmittal 
of the control page size may not be necessary, however, since each control 
page data word is proceeded by a preamble and 32 bit sync string and since 
the receiver circuitry 12 is periodically activated by the receiver strobe 
circuitry 30 in cycles that insure that it is activated in a timely 
fashion so as to receive the preamble of selective call signals and hence 
the transmitted selective call signal. 
The receiver circuitry 12 is activated and deactivated to conserve battery 
time. During the de-energized state, the receiver circuitry is not powered 
or activated to receive transmissions. The receiver sleep time is, 
however, less than the preamble period of any transmitted messages so that 
the receiver circuitry 12 is always activated in time to detect the 
presence of a signed preamble. When a preamble is detected, the device 
demodulates the preamble and follows the previous routine of ascertaining 
the proper baud rates for compatibility. If compatible, the system 
demodulates the selective call signal and pulls the page address to 
determine correlation. If the page address matches the address of the 
device, then the OTA software upgrade program is downloaded in memory and 
the device returns to its previous mode. If the selective call signal is a 
control page then the data may also be stored in memory. 
The memory 28 of the instant invention is a temporary nonvolatile memory to 
store the new code received via the OTA software transmission for 
programming the selective call receiver upgrade. It may also be used to 
temporarily store the control page message. 
The method of transmission, receiving and decoding is dependant on the 
device and protocol. For instance, the POCSAG protocol transmits a 576 bit 
preamble, 32 byte sync code and data batches, which include 8 frames per 
batch. If the baud rate of the preamble correlates to the baud rate of the 
device, then the control page 200 is received. As will be appreciated by 
skilled artisans, each device is programmed to store its address in one of 
the 8 frames with a most significant bit (MSB) of "0." The MSB for data 
strings is "1." When the processor correlates the control page data word 
address with the device control page address it first checks for the 
proper frame designation. That is, if the frame designation matches, then 
a bit to bit comparison is performed. After the control page address is 
confirmed, then the device receives, decodes and stores the control page 
data information of which is included the time and size of the upgrade 
code. The time and size data may be stored in memory as previously noted. 
In accordance with FIGS. 2 and 3, the instant invention provides a method 
(100) for automatically receiving an OTA software upgrade page 210 in the 
form of selective call signals at predetermined times and transparent to 
the selective call receiver user/owner so that the selective call receiver 
may be placed in the "off mode" to conserve and extend battery life 
without missing the OTA software upgrade page. The instant invention 
generally comprises the steps of sending and receiving a first selective 
call signal or control page 200, having program time data, a predetermined 
number of times (110); decoding, processing, and detecting programming 
related information such as time; storing this control page information in 
the targeted selective call receiver (112, 116); comparing the stored 
programming time with a timing signal generated by nonvolatile internal 
timer 24; activating the selective call receiver automatically at the 
preselected time indicated by a control pager related signal (120-136); 
receiving the OTA software upgrade code; and storing it in the memory of 
the device (140-148). 
During a predetermined time of day, while most selective call receivers are 
active, a series of control page data words are sent from the device's 
control center, or some other location, a predetermined number of times, 
as shown in FIG. 4 (110). The selective call receiver 10 receives the 
control page data word via its receiver and demodulator circuitry 12, 
demodulates the control page 200, and processes the transmitted 
information (112-116). The selective call receiver 10 processes the 
control page data word, as previously discussed, by processing the 
preamble and sync code, verifying correlation, and decoding the received 
control page data word. The time, and possibly expected new code size, is 
stored in either program memory for subsequent retrieval and correlation. 
According to FIG. 2 (120), the actual time or time signal generated by the 
nonvolatile internal timer 24 is correlated with the programming time 
provided by the control page information until a match is achieved or 
determined. Once the time correlator 26 responds in the affirmative with a 
correlated time, it sends a signal to the processor to check the pager's 
"on" status and to prepare for OTA programming (124, 128). If the 
selective call receiver, or pager, is not in the "on" mode, then the 
processor provides a signal to the power enabling circuitry until 
receiving a de-energizing signal so that the OTA upgrade may be received 
(128-132). If the selective call receiver is already powered, then the 
processor sends an activate signal to the receiver strobe circuitry 30, 
thereby activating the receiver for receiving the expected OTA upgrade 
message (128-136). The selective call receiver is then prepared for 
receiving the OTA software upgrade page 210. The processor 22, thereafter, 
maintains the receiver circuitry 12 in the active mode until the expected 
OTA upgrade message is received (140-143). In accordance with the instant 
invention, it is important to note that the processor 22 only allows the 
selective call receiver to be activated for receiving the expected OTA 
upgrade message and no other pages pursuant to the signal request from the 
time correlator 26 or the information provided by the control page data 
word in flash RAM 28. 
The processor 22 keeps the receiver alive to receive the expected OTA 
software upgrade page for a predetermined amount of time. The 
predetermined receiver activity or sniff time is processed and correlated 
by time correlator 26 with the actual time provided by the nonvolatile 
internal timer 24. Once the allotted time for looking elapses, as 
determined by the time correlator 26, then the device is de-energized to 
conserve battery power and it returns to its previous pager mode. Upon 
receiving the OTA upgrade message, the processor stores the new code 
program in program flash RAM 26 (144). The processor then programs the 
device with the new code or data transmitted in the OTA software upgrade 
in accordance with the information provided. Once the programming is 
complete, the selective call receiver is de-energized in accordance with a 
signal provided by the processor 22, and returned to its previous pager 
mode (148).