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Mobile Phone Patent Abstract
The procedure for Over-The-Air Parameter Administration (OTAPA)
utilizes the over-the-air programming protocol and procedures which
support the Over-The-Air Service Provisioning (OTASP) feature in
accordance with established industry standards (TIA/EIA/IS-683).
The mobile phone is programmed with a service option for changing
the NAM parameters including an identification number for this option.
The network base station sends a message to the mobile phone using
the identification number and, if the mobile phone has OTAPA capability,
it responds indicating support. The base station then transmits
message telling the mobile station to proceed to the Traffic Channel
and inquires whether the encryption mode is enabled, proceeding
with the OTAPA only if the encryption mode is enabled. Once on the
Traffic Channel, a Parameter Change Code (PCC) is sent. If the PCC
is verified by the mobile unit, the base station proceeds to update
the parameters and store the updated parameters into the phone's
memory. After verification of the programmed data in accordance
with OTASP processing, the process is terminated. No user intervention
is required to initiate or conduct the OTAPA procedure.
Mobile Phone Patent Claims
I claim:
1. A method for making changes in at least one of a plurality of
operating parameters of a mobile phone which operates within a network,
the plurality of operating parameters being stored within a non-volatile
memory, the method comprising:
providing an encryption means for securing communications between
the mobile phone and the network;
programming the mobile phone with a parameter change service option
and at least one parameter change code for permitting over-the-air
changing of operating parameters;
transmitting a page message from a base station within the network
to the mobile phone, the page message including an inquiry as to
the identity of the mobile phone and the presence of the parameter
change service option;
transmitting a page response message from the mobile phone to the
base station verifying the identity of the mobile phone and the
presence of the parameter change service option;
transmitting instructions from the base station to the mobile phone
to enter an over-the-air service provisioning process;
transmitting the at least one parameter change code from the base
station to the mobile phone;
transmitting from the mobile phone to the base station a response
verifying the at least one parameter change code;
downloading updated operating parameters corresponding to the at
least one parameter change code from the base station to the mobile
phone;
storing the updated operating parameters in the non-volatile memory;
and
transmitting from the base station to the mobile phone a call releasing
message.
2. The method of claim 1, wherein the encryption means comprises
a programmable encryption mode and the step of programming the mobile
phone includes programming the programmable encryption mode to enable
message encryption.
3. The method of claim 2, wherein the page message includes an
inquiry to confirm that the programmable encryption mode is enabled.
4. The method of claim 1, wherein the encryption means comprises
a permanent encryption code for encrypting all communications between
the mobile phone and the base station.
5. The method of claim 1, wherein the plurality of operating parameters
are divided into a plurality of parameter groups and wherein said
at least one parameter change code comprises a plurality of parameter
change codes with one parameter change code corresponding to each
parameter group of the plurality of parameter groups.
6. The method of claim 1, wherein the at least one parameter change
code is an authentication key for the mobile phone.
7. The method of claim 1, wherein the step of determining whether
the mobile phone is set up for message encryption comprises:
transmitting a channel assignment message from the base station
to the mobile phone wherein the channel assignment message has an
encryption mode turned on; and
transmitting a response from the mobile phone to the base station
verifying that the encryption mode is turned on.
8. The method of claim 1, wherein the step of programming the mobile
phone comprises assigning one service option number from a plurality
of service option numbers for the parameter service option and setting
the value of the one service option number to "1".
9. The method of claim 8, wherein the page response message includes
a field containing the one service option number.
10. The method of claim 1, wherein the at least one parameter change
code has a pre-set value.
11. The method of claim 10, wherein the pre-set value of the at
least one parameter change code may be changed to a different value
only by intervention of a user of the mobile phone.
12. The method of claim 1, wherein the step of downloading updated
operating parameters includes downloading the updated operating
parameters using the over-the-air service provisioning process according
to the IS-683 standard.
13. A method of claim 1, wherein the step of determining whether
the mobile phone is set up for message encryption further includes
transmitting a channel assignment message to the mobile phone.
14. The method of claim 1, wherein the step of transmitting instructions
to enter an over-the-air service provisioning process includes transmitting
data burst messages.
15. A wireless communications network having a base station with
a service administrator, and a mobile station, the mobile station
having a plurality of operating parameters stored within a non-volatile
memory, at least a portion of the plurality of operating parameters
which may be changed by the service administrator, the network comprising:
message encryption means for securing communications between the
base station and the mobile station;
means for programming the memory of the mobile station wherein
the mobile station has programmable options for over-the-air parameter
changes, the mobile station being set to enable the programmable
options;
means for initiating a call from the base station to the mobile
station when the mobile station is in an idle mode, the call comprising
a paging message for interrogating the mobile station to confirm
a mobile station identity and that the programmable options for
over-the-air parameter changes are enabled;
means for terminating the call if the programmable options for
over-the-air parameter changes are not enabled;
means for instructing the mobile phone to enter into an over-the-air
service provisioning process;
means for enabling a download of updated operating parameters from
the base station to the mobile station including transmitting a
parameter change code portion within the programmable options for
over-the-air parameter changes;
means for storing the updated operating parameters in the non-volatile
memory; and
means for terminating the call.
16. The network of claim 15, wherein the message encryption means
comprises a programmable encryption mode and the means for programming
the memory of the mobile station includes means for programming
the programmable encryption mode to enable message encryption.
17. The network of claim 16, wherein the paging message includes
an inquiry to confirm that the programmable encryption mode is enabled.
18. The network of claim 15, wherein the message encryption means
includes a permanent encryption code for encrypting all communications
between the mobile station and the base station.
19. The network of claim 15, wherein the over-the-air service provisioning
process is in accordance with the IS-683 standard.
20. The network of claim 15, wherein the plurality of operating
parameters are divided into a plurality of parameter groups and
each parameter group of the plurality has a corresponding parameter
change code.
21. The network of claim 15, wherein the parameter change code
is an Authentication key for changing a Shared Secret Data set of
the mobile station.
22. The network of claim 15, wherein the paging message includes
a channel assignment message from the base station to the mobile
phone wherein the channel assignment message has an encryption mode
turned on and a response message from the mobile phone to the base
station verifying that the encryption mode is turned on.
23. The network of claim 15, wherein the means for programming
includes a data field having a plurality of service option numbers
including one service option number corresponding to a parameter
service option for over-the-air parameter changes and setting the
value of the one service option number to "1".
24. The network of claim 15, wherein the parameter change code
portion has a pre-set value.
25. The network of claim 24, wherein the pre-set value of the parameter
change code portion may be changed to a different value only by
intervention of a user of the mobile station.
26. A method for administering a wireless communications network
comprising a base station and a plurality of mobile phones, each
mobile phone having an identity and a plurality of operating parameters
stored in a non-volatile memory, at least a portion of the operating
parameters which require updating, wherein a user of the mobile
phone is not required to initiate a procedure for updating the operating
parameters, the method comprising:
programming the mobile phone with a parameter change service option
and at least one parameter change code for permitting over-the-air
changing of operating parameters;
when an update to the operating parameters is required, transmitting
a General Page Message from a base station to the mobile phone in
an Idle Mode, the General Page Message including a request to verify
the identity of the mobile phone and a first data field for the
parameter change service option;
receiving a Page Response Message from the mobile phone to the
base station including the identity of the mobile phone and the
first data field for the parameter change service option;
transmitting a Channel Assignment Message from the base station
to the mobile phone, the Channel Assignment Message including a
second data field for message encryption and instructing the mobile
phone to set up a traffic channel;
receiving a response from the mobile phone including the second
data field to verify message encryption;
terminating the transmission from the base station if message encryption
is not verified;
transmitting a Data Burst Message from the base station to the
mobile phone instructing the mobile phone to enter an over-the-air
service provisioning process;
transmitting a Protocol Capability Request Message from the base
station to the mobile phone, the Protocol Capability Request Message
including a third data field for feature capability of the mobile
phone;
receiving a Protocol Capability Response Message from the mobile
phone indicating the third data field;
transmitting the at least one parameter change code from the base
station to the mobile phone;
transmitting from the mobile phone to the base station a response
verifying the at least one parameter change code;
downloading updated operating parameters corresponding to the at
least one parameter change code from the base station to the mobile
phone; and
transmitting a Data Commit Message from the base station to the
mobile phone for storing the updated operating parameters in the
non-volatile memory and for releasing the call.
27. The method of claim 26, wherein the at least one parameter
change code has a pre-set value.
28. The method of claim 27, wherein the pre-set value of the at
least one parameter change code may be changed to a different value
only by intervention of a user of the mobile phone.
29. The method of claim 26, wherein the step of downloading updated
operating parameters includes downloading the updated operating
parameters using the over-the-air service provisioning process according
to the IS-683 standard.
30. The method of claim 26, wherein the at least one parameter
change code is an A-key for changing a set of Shared Secret Data
for the mobile phone.
Mobile Phone Patent Description
FIELD OF THE INVENTION
This invention relates generally to administration of parameters
for operation of mobile telephones, and more specifically to a method
for maintaining, changing, and/or updating of mobile phone parameters
by a network service provider without requiring intervention by
the mobile phone user.
BACKGROUND OF THE INVENTION
Over-the-air service provisioning (OTASP) for activation of mobile
phones, both cellular and PCS, which allows a network service provider
to activate new service without intervention of a third party, such
as an authorized dealer, is well known, with established standards
provided in Telecommunications Industry Association/Electronics
Industries Association Interim Standard 683 (TIA/EIA/IS-683). OTASP
enables the service provider to activate a potential subscriber's
(mobile user's) mobile phone by downloading the required parameters,
e.g., a phone number, over the air to the mobile unit. Since a qualified
dealer or service agent is not required to initiate the procedure,
service providers have the capability of marketing mobile phones
through general merchandise-type retail stores, such as drug stores
and discount department stores, rather than specialty electronics
stores. OTASP also provides the ability to securely load an authentication
key ("A-Key") into the mobile unit to allow validation
and confirmation of the identity of the mobile unit to enhance security
and reduce the potential for fraudulent use of the network service.
OTASP can be initiated only by the user and requires connection
to the service provider's customer service center for interaction
with a customer service representative.
At the time of activation, in addition to the phone number and
security code, values known as Number Assignment Modules (NAMs)
are downloaded into the memory of the mobile unit from the base
station. The NAMs specify parameters which control wireless network
usage, such as preferred mode of operation (analog or digital),
shared secret data (SSD), and roaming information, or "Preferred
Roaming List". A list of numeric indicators is provided in
Appendix F of the TIA/EIA/IS-95-A standard and is incorporated herein
by reference. Once this initial programming is completed, because
the link is broken, the network service provider has little control
of the NAM parameters, unlike equivalent parameters in wired telephone
networks. Typically, changes made after initial activation, which
can include change of the area code of the phone number, or changes
in Preferred Roaming List parameters based upon new service areas
and/or new roaming agreements with other network providers, need
to be made with intervention of the subscriber--either by initiating
communication with the network or by taking the mobile unit to an
authorized dealer or service agent. This can result in many of the
changes being left undone since the subscriber may be too busy or
simply does not want to bother making the effort. Further, improvements
in technology are constantly being made which may be appropriate
for automatic incorporation into existing services without requiring
user input, e.g., changeover from analog to digital service. Another
problem resulting from the loss of control of the mobile phone parameters
(NAMs) is that the service provider has no means for preventing
the purchaser of a phone which the provider subsidized from going
to a competitor to have the service transferred prior to the expiration
of a contracted minimum subscription period. Thus, situations exist
where it may be appropriate or desirable for the network service
provider to access the mobile unit to maintain or change parameters
within the mobile unit without requiring the involvement of the
subscriber.
The capability of making over the air network-initiated changes
of mobile station NAMs raises significant concerns regarding security,
i.e., interception of the change code, and fraud, including unauthorized
changing of parameters, including changing of networks, by competing
service providers, a practice often referred to as "slamming".
For these reasons, such capabilities have been heretofore unavailable,
and the need remains for a secure procedure for making possible
over-the-air parameter maintenance and changes.
SUMMARY OF THE INVENTION
It is an advantage of the present invention to provide a means
for allowing network-initiated over-the-air access to a mobile station's
Number Assignment Module (NAM) without requiring user intervention.
It is another advantage of the present invention to provide means
for simplifying the administration of NAM parameters by a network
service provider.
Yet another advantage of the present invention is to provide means
for preserving security and integrity of NAM parameters to prevent
unauthorized access.
In an exemplary embodiment of the present invention, the procedure
for Over-The-Air Parameter Administration (OTAPA) utilizes the over-the-air
programming protocol and procedures which support the Over-The-Air
Service Provisioning (OTASP) feature in accordance with established
industry standards (TIA/EIA/IS-683). The mobile phone is programmed
with a service option for changing the NAM parameters--the Parameter
Administration Service Option (PASO), which includes assignment
of a PASO number. The mobile phone will also have one or more parameter
change codes (PCCs) in its memory. The network possesses means for
determining whether a mobile phone is OTAPA capable. In this procedure,
the network base station sends a General Page Message to the mobile
phone using the PASO number. After first verifying its identity
using the standard Authentication process, if the mobile phone has
OTAPA capability, it responds with a Page Response Message, indicating
support for the PASO by sending the PASO number. If the mobile station
does not support the option, the response will indicate that the
option is not available. Once the presence of the option is confirmed,
the base station transmits a Channel Assignment Message, telling
the mobile station to proceed to the Traffic Channel. For security
reasons, the Signaling Message Encryption (SME) is used in the Channel
Assignment Message. Use of encryption is enforced, and, where encryption
is optional, if the encryption mode is not enabled, the mobile station
will enter into the Service Negotiation process on the Traffic Channel
and will request the other service option, indicating that the PASO
is not supported, or will terminate the call according to the Call
Release Procedure.
Once the mobile station is on the Traffic Channel, an OTASP Data
Message is sent containing a Parameter Change Code (PCC). If the
PCC matches the PCC for the mobile phone, it is verified by the
mobile unit, after which it may be used to unlock the mobile station,
update the parameters and store the updated parameters into the
phone's memory. After verification of the programmed data in accordance
with OTASP processing, the process is terminated. A number of different
PCCs may be used for different parameters, or different groups of
parameters per NAM. The PCC for a mobile unit will initially have
a pre-set default value which can only be changed with user intervention
to prevent unauthorized changes. As long as the PCC value remains
the same, no user intervention is required for any other parameter
changes which are initiated by the network service provider.
BRIEF DESCRIPTION OF THE DRAWINGS
Understanding of the present invention will be facilitated by consideration
of the following detailed description of preferred embodiments of
the present invention taken in conjunction with the accompanying
drawings, in which like numerals refer to like parts, and in which:
FIG. 1 is a block diagram of an exemplary mobile phone receiver;
and
FIG. 2 is a diagram of an exemplary OTAPA call flow for changing
a Roaming List according to the present invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
The following detailed description utilizes a number of acronyms
which are generally well known in the art. While definitions are
typically provided with the first instance of each acronym, for
convenience, Table 1 below provides a list of the acronyms and abbreviations
used herein along with their respective definitions.
TABLE 1 ______________________________________ ACRONYM DEFINITION
______________________________________ A-Key Authentication Key
ANSI American National Standards Institute BS Base Station CDMA
Code Division Multiple Access EIA Electronics Industries Association
HLC/AC Home Location Register/Authentication Center IS Interim Standard
MS Mobile Station NAM Number Assignment Modules NID Network IDentification
OTAPA Over-The-Air Parameter Administration OTASP Over-The-Air Service
Provisioning PASO Parameter Administration Service Option PCC Parameter
Change Code RAM Random Access Memory SID System IDentification SME
Signaling Message Encryption SPASM Subscriber Parameter Administration
Security Mechanism SPC Service Programming Code SPL Service Programming
Lock SSD Shared Secret Data SSPR System Selection for Preferred
Roaming TIA Telecommunications Industry Association ______________________________________
It should be noted the font variations within the specification
and claims, particularly italicized text and text in all capital
letters, reflect the formats established according to the various
standards which are applicable to wireless communications, e.g.,
IS-95 and IS-683.
Referring to FIG. 1, a conventional mobile phone receiver, which
is generally designated by reference numeral 1, typically comprises
an antenna 10 for receiving call signals. The received signals are
provided to a receiver and a demodulator circuit 20 and the resulting
digital signal is fed to a microcontroller 30. Microcontroller 30
comprises a decoder 32, a processor 34, and an internal RAM 36.
The digital signal is decoded by the decoder 32 and processed by
processor 34, which reads from or writes to internal RAM 36. Memory
storage for the mobile phone parameters is provided by RAM 40. The
user can enter data into processor 34 via user input circuitry 60.
A non-volatile memory 50 is coupled to processor 34 for storage
of information necessary for the operation of mobile phone receiver
1. The memory can be an electrically erasable programmable read
only memory (EEPROM), a battery backed up memory device, or a similar
memory device which retains information even when power is not applied
to the mobile phone. Processor 34 accesses information such as options
for various features from non-volatile memory 50 during operation,
and can alter information in the memory 50 by reprogramming in accordance
with the present invention.
The procedure for Over-The-Air Parameter Administration (OTAPA)
utilizes the over-the-air programming protocol and procedures which
support the Over-The-Air Service Provisioning (OTASP) feature in
accordance with established industry standards (TIA/EIA/IS-683).
The IS-683 standard, which is incorporated herein by reference,
provides the technical requirements for a network operating in either
the analog or the wideband spread spectrum (CDMA) mode conforming
with TIA/EIA/IS-95 or ANSI J-STD-008. The following detailed description
specifically refers to a CDMA network, however, it will be apparent
to those skilled in the art that by substituting the corresponding
protocol and processes for analog networks according to the IS-683
standard, the inventive parameter administration method may be similarly
implemented in an analog network.
Stored within the non-volatile memory 50 of mobile phone is the
programming for a service option for changing the NAM parameters.
This option, the Parameter Administration Service Option (PASO),
includes assignment of a PASO number to the mobile unit. When the
network service provider wishes to update parameters in a particular
mobile unit, the base station initiates a Mobile Terminated Call
by sending a General Page Message which, along with initial inquiries
regarding the availability of a special service option (SPECIAL.sub.--
SERVICE set to "1") and the presence of the PASO option
(SERVICE.sub.-- OPTION set to "1"), includes the PASO
number for that mobile phone. The mobile terminated call will use
a new service option, which may, for illustration purposes, be referred
to as "Parameter Administration" (Service Option No. X).
As in the case of any new features in a standardized systems and
data formats, addition of a new service option number will requires
changes to existing IS-41 (Network Specification) specified messages,
or new messages will need to be defined by the standards organizations.
Initiating such changes is an administrative task that will be readily
apparent to those in the art.
The mobile station, which is preferably in Mobile Station Idle
State with power on and CDMA system acquired, receives the page
message and searches the message to determine, first, whether the
base station and mobile station possess identical sets of Shared
Secret Data (SSD) in accordance with standard authentication procedures,
and second, the message contains the mobile unit's PASO number.
At this point, no Speech Service Option is required since the procedures
for the OTAPA feature only requires message exchange over the air.
Assuming the authentication process is successful, if the PASO number
matches, the mobile unit responds with a Page Response Message,
acknowledging support for the PASO by responding to acknowledge
that SPECIAL.sub.-- SERVICE is set to "1" and SERVICE.sub.--
OPTION X for Parameter Administration is set to "1", and
sending the PASO number.
If the mobile station does not support the OTAPA option, i.e.,
the SERVICE.sub.-- OPTION X field is set to "0", an option
number will not be sent in response. If the mobile unit is engaged
in another service option, e.g., voice, it may be preferable to
include a response to a General Page Message containing the PASO
number to indicate that the base station should remain in a Waiting
for Answer Task, or should terminate the call and try later to reduce
network complications.
Once the presence of the option is confirmed (SERVICE.sub.-- OPTION
X field is set to "1") the base station transmits a Channel
Assignment Message, instructing the mobile station to proceed to
the Traffic Channel. For security, the Signaling Message Encryption
(SME) is used by setting ENCRYPT.sub.-- MODE to "01" in
the Channel Assignment Message. Because of the significant potential
for fraud or other misuse of parameter change capabilities, the
use of encryption is strictly enforced. Therefore, if the encryption
mode is not enabled (ENCRYPT.sub.-- MODE set to "00"),
the mobile station will enter into the Service Negotiation process
on the Traffic Channel and will reject the PASO by requesting the
other service option, i.e., SERVICE.sub.-- OPTION X set to "0",
indicating that the PASO is not supported, or will terminate the
call according to the Call Release Procedure.
In the event that standards are adopted such that the message encryption
mode is not optional, but is always enabled, verification of enablement
of an encryption option may not be necessary, and the above-described
steps involving the paging message and response can omit the verification
that the encrypt mode is enable.
Once the mobile station is on the Traffic Channel in the OTASP
mode, the OTASP Data Message processing procedure is used to unlock
the mobile station, update the parameters and store the updated
parameters into the phone's memory as follows, then terminate the
OTASP process. A number of different unlock codes may be used for
different parameters, or different groups of parameters per NAM,
as described in more detail below.
As specified in the IS-683 standards, delivery of OTASP Data Messages
does not require sequential delivery of messages by the layer 2
protocol because OTASP procedures ensure that only one OTASP Data
Message is outstanding at any time. Therefore, a Data Burst Message
(OTASP BURST.sub.-- TYPE) may be used in accordance with TIA/EIA/TSB58,
"Administration of Parameter Value Assignments for TIA/EIA
Wideband Spectrum Standards". Data Burst Messages may also
be used on the Control Channel (Paging/Access Channel) per IS-95
specifications. The OTASP BURST.sub.-- TYPE messages may be expanded
over the control channel for OTAPA purposes.
The base station checks the mobile station's OTASP feature capability
using the OTASP Data Message designated as the Protocol Capability
Request Message (OTASP.sub.-- MSG.sub.-- TYPE field set to "00000110"),
to which the mobile station responds with a Protocol Capability
Response Message (with the same field setting). New feature capabilities
are defined for OTAPA and may be indicated in the fields of the
Protocol Capability Request/Response Messages designated as NUM.sub.--
FEATURES, FEATURE.sub.-- ID, and FEATURE.sub.-- P.sub.-- REV. The
existing standards for the FEATURE.sub.-- P.sub.-- REV field includes
reserved values for future standardization, selected values of which
may be used for OTAPA standardization.
To unlock the parameters in the mobile unit, the Parameter Change
Code (PCC), i.e., a password, is required. If the PCC is correct
and verified by the mobile station, the parameters under the control
of this PCC can be updated. A separate PCC may be assigned for different
parameters or groups of parameters, e.g., NAM values or Roaming
Lists may have different PCCs. The default value for PCC is "000000".
In some mobile phones, if the Service Programming Lock (SPL) is
supported, the PCC can be the same as the Service Programming Code
(SPC) used in the SPL. The Authentication key (A-Key checksum),
which is used to update SSD and, thus, is known only to the mobile
station and its associated Home Location Register/Authentication
Center (HLC/AC), may also be used as a PCC. The updated parameters
are downloaded into the permanent memory, i.e., non-volatile memory
50. (In accordance with standard OTASP procedures, if the NAM values
or other parameter values are not stored in permanent memory, they
will be discarded by the mobile station.)
Data message processing involved in OTAPA follows the same procedures
designated under the IS-683 for OTASP, with a difference being that
initiation of the procedure does not require the intervention of
the mobile user. Once the PCC is set, which does require user intervention,
the network provider can change or update mobile phone parameters
as long of the mobile unit is in the Idle Mode.
New OTASP Data Messages will need to be assigned by the standards
organizations to support the PCC verification/change process from
the base station. When the base station sends the PCC via the OTASP
Data Message, the mobile station validates the PCC before allowing
any parameters to be updated.
To prevent the unauthorized changing of a PCC from the default
value to a non-default value, subscriber authorization is required.
Thus, when the base station sends the OTASP Data Message to change
the PCC from default to non-default, the mobile station must always
wait for the user's authorization before any change(s) in the PCC(s)
can take place.
After the network service provider has updated the desired parameters,
the OTASP data commit procedure using the Commit Request Message
(OTASP.sub.-- MSG.sub.-- TYPE set at "00000101") is used
to make the new parameters effective and to terminate the OTAPA
call. Depending on the nature of the changes, some parameters may
require the mobile station to run through a power cycle before the
parameter is activated.
FIG. 2 provides an exemplary call flow for changing the Roaming
List parameters. In accordance with IS-95, the mobile station has
a list of one or more home (non-roaming)(SID,NID) pairs (network
identification (NID) and system identification (SID)). A change
in the Roaming List would be initiated if, for example, two cellular
systems merged or established an arrangement which permitted their
subscribers to travel between the two systems without incurring
roaming charges, or if a new network were added within the cellular
system to which the mobile user subscribes. The following assumptions
apply:
1) The Mobile Station and Base Station each supports the OTAPA
service option:
2) The Mobile Station is powered up and the user is not talking
on the phone (not in voice mode);
3) The Base Station and the Mobile Station have already performed
the Authentication process successfully (in accordance with established
authentication procedures under IS-95);
4) The Base Station (Network) supports Signaling Message Encryption
(SME), including authentication; and
5) The Parameter Change Code (PCC) of Roaming List update is programmed
into the Mobile Station.
In FIG. 2, the Mobile Station is generally designated as 100 and
the Base Station as 200. Mobile Station 100 is in the Idle State
101 when, at the direction of the Network Service Administrator,
Base Station 200 initiates a Mobile terminated call 201 on Paging
Channel 150, sending a General Page Message 202 which includes the
OTAPA service option (SERVICE.sub.-- OPTION X set to "1").
Mobile Station 100 receives the page message and processes the OTAPA
Service Option request 102. Per the assumptions, Mobile Station
100 supports the OTAPA Service Option. Mobile Station 100 responds
on Access Channel 160, sending a Page Response Message 103 confirming
the mobile's support of the OTAPA Service Option. Base Station 200
Process the Page Response Message and enables the Signaling Message
Encryption (SME) 203 and, still on Paging Channel 150, sends a Channel
Assignment Message 204 which includes the encryption mode turned
on (ENCRYPT.sub.-- MODE set to "01"). Mobile Station 100
processes the Channel Assignment Message and verifies the SME, then
sets up the designated Traffic Channel 170 according to IS-95 procedures
104.
Base Station 200 sends a Data Burst Message using OTASP BURST-TYPE
fields 205 and transmits the message to Mobile Station 100 over
Traffic Channel 170. This message includes a Protocol Capability
Request Message. (All subsequent communications for this procedure
occur over Traffic Channel 170.) Mobile Station 100 processes Data
Burst Message 205 and enters into the OTASP process according to
IS-683 (step 105), and responds to indicate OTAPA feature capability
105 by sending a Protocol Capability Response Message in step 106.
In step 206, Base Station 200 transmits the Parameter Change Code
(PCC) for the Mobile Station 100. If the Mobile Station has more
than one PCC, the Base Station 200 will specifically select the
PCC for updating the Roaming List. Assuming the PCC is correct,
Mobile Station 100 receives and validates the transmitted PCC.
Still communicating over Traffic Channel 170, in steps 207 and
107, Base Station 200 and Mobile Station 100, respectively, follow
the System Selection for Preferred Roaming (SSPR) procedure for
Roaming List update as set forth in IS-683-A. After the updated
roaming information is fully downloaded, in step 208, Base Station
200 initiates the OTASP Data Commit process by sending a Data Commit
Message (OTASP.sub.-- MSG TYPE field set to "00000101")
in accordance with IS-683, telling Mobile Station 100 to process
and update the Roaming List. Mobile Station receives the Data Commit
Message and sets the field of the data commit result code to indicate
acceptance of the Data Commit Message (RESULT.sub.-- CODE set to
"00000000") and to store the new data in permanent memory.
(Note that, in accordance with IS-683), if any errors are detected
in the data, the RESULT.sub.-- CODE will be set to the appropriate
value to indicate the nature of the error.) After acceptance is
indicated by Mobile Station 100, the call is released.
The Over-The-Air Parameter Administration method of the present
invention provide the advantage of allowing a network service provider
to initiated over-the-air access to a mobile station's Number Assignment
Module (NAM) without requiring user intervention, allowing for actions
to be taken to protect the service provider's resources as well
as to improve service to its subscribers. The strict enforcement
of encryption procedures provides means for preserving security
and integrity of NAM parameters to prevent unauthorized access,
including unauthorized switching of service providers or "slamming".
The inventive procedure also may be useful in assisting in the deterrence
and apprehension of persons who have hijacked a subscriber's account
by stealing their mobile phone or by intercepting and using a transmission
from a mobile station. The OTAPA procedure can be initiated using
existing OTASP protocols and procedures, requiring minimal changes
to standards.
Other embodiments and modifications of the present invention will
occur readily to those skilled in the art in view of these teachings.
Therefore, this invention is to be limited only by the following
claims, which include other embodiments and modifications when viewed
in conjunction with the above specification and accompanying drawings.
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