U.S. patent application number 09/783196 was filed with the patent office on 2001-07-26 for method and apparatus providing residential base carrier inactivation after line failure or line in use.
Invention is credited to Alanara, Seppo M..
Application Number | 20010009851 09/783196 |
Document ID | / |
Family ID | 25324465 |
Filed Date | 2001-07-26 |
United States Patent
Application |
20010009851 |
Kind Code |
A1 |
Alanara, Seppo M. |
July 26, 2001 |
Method and apparatus providing residential base carrier
inactivation after line failure or line in use
Abstract
A personal base station (38) includes a transceiver (38b , 38c)
coupled to an antenna (38d) for conducting bidirectional wireless
communications with a mobile station (10); an interface (38g) to a
telephone line; and a controller (38a) that includes a circuit
(38f) for sensing that the telephone line is not available for use.
The controller is responsive to the telephone line not being
available for use for notifying a mobile station that the mobile
station is to register with a cellular communication system (32).
In a preferred embodiment of this invention the sensing circuit is
operable to discriminate between a disconnection of the telephone
line and the use of the telephone line. In the first case the
disconnect message may be sent immediately, while in the latter
case the disconnect message may be sent after some predetermined
time delay. In one embodiment the controller formats and transmits
a message to the mobile station for notifying the mobile station
that the mobile station is to register with the cellular
communication system, while in another embodiment the controller
terminates a transmission of an RF carrier signal to the mobile
station for notifying the mobile station that the mobile station is
to register with the cellular communication system. Methods for
operating the personal base station are also disclosed.
Inventors: |
Alanara, Seppo M.; (Oulu,
FI) |
Correspondence
Address: |
PERMAN & GREEN
425 POST ROAD
FAIRFIELD
CT
06430
US
|
Family ID: |
25324465 |
Appl. No.: |
09/783196 |
Filed: |
February 14, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09783196 |
Feb 14, 2001 |
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08856769 |
May 15, 1997 |
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6212375 |
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Current U.S.
Class: |
455/426.1 ;
455/445; 455/462; 455/525; 455/528; 455/561; 455/68 |
Current CPC
Class: |
H04M 1/724 20210101;
H04W 24/04 20130101; H04W 52/28 20130101; H04M 1/72505
20130101 |
Class at
Publication: |
455/426 ;
455/445; 455/462; 455/525; 455/528; 455/561; 455/553; 455/68 |
International
Class: |
H04Q 007/20 |
Claims
What is claimed is:
1. A method for operating a wireless communications system of a
type that includes a mobile station, a base station connected to a
public cellular communication system, and a personal base station,
comprising the steps of: sensing that a telephone line connected to
the personal base station is not available for use; and notifying
the mobile station that the mobile station is to obtain service
from the public cellular communication system.
2. A method as set forth in claim 1, wherein the step of notifying
includes a step of transmitting a message to the mobile station
from the personal base station.
3. A method as set forth in claim 1, wherein the step of notifying
includes a step of immediately terminating a transmission of an RF
carrier signal to the mobile station from the personal base
station.
4. A method as set forth in claim 1, wherein the step of sensing
includes a step of discriminating between a disconnection of the
telephone line and the use of the telephone line.
5. A method for operating a wireless communications system of a
type that includes a mobile station, a base station connected to a
public cellular communication system, and a personal base station,
comprising the steps of: sensing that a telephone line connected to
the personal base station is not available for use, the step of
sensing including a step of discriminating between a disconnection
of the telephone line and the use of the telephone line; for the
case where the telephone line is determined to be disconnected,
notifying the mobile station that the mobile station is to register
with the public cellular communication system; and for the case
where the telephone line is determined to be in use, delaying for a
period of time and, if the telephone line is still in use,
notifying the mobile station that the mobile station is to register
with the public cellular communication system.
6. A method as set forth in claim 5, wherein the steps of notifying
each include a step of transmitting a message to the mobile station
from the personal base station.
7. A method as set forth in claim 5, wherein the steps of notifying
each include a step of terminating a transmission of an RF carrier
signal to the mobile station from the personal base station.
8. A personal base station, comprising: a transceiver coupled to an
antenna for conducting bidirectional wireless communications with a
mobile station; an interface to a telephone line; and a controller
including a circuit for sensing that said telephone line is not
available for use, said controller being responsive to said
telephone line not being available for use for notifying a mobile
station that the mobile station is to obtain service from a
cellular communication system.
9. A personal base station as set forth in claim 8, wherein said
sensing circuit is operable to discriminate between a disconnection
of the telephone line and the use of the telephone line.
10. A personal base station as set forth in claim 8, wherein said
controller formats and transmits a message to the mobile station
for notifying the mobile station that the mobile station is to
register with the public cellular communication system.
11. A personal base station as set forth in claim 8, wherein said
controller terminates a transmission of an RF carrier signal to the
mobile station for notifying the mobile station that the mobile
station is to register with the public cellular communication
system.
Description
FIELD OF THE INVENTION
[0001] This invention relates generally to radiotelephones and, in
particular, to radiotelephones or mobile stations such as those
capable of operation with a cellular network and also with a
residential or personal base station.
BACKGROUND OF THE INVENTION
[0002] In some modern wireless communications systems a mobile
station, such as a cellular telephone or wireless communicator, is
enable to operate in two frequency bands. In a first frequency band
the mobile station is able to make and receive calls through a
conventional cellular network having base stations and a mobile
switching network. In a second frequency band the mobile station is
able to make and receive calls through a local or residential base
station, also sometimes referred to as a personal base station. By
example, when entering a building (such as a residence or an
office) having a personal base station the mobile station
automatically switches from the first frequency band to the second
frequency band. Appropriate signalling and message formats are used
to inform the telephone network that any calls to the mobile
station should be routed to a telephone number associated with the
personal base station. If an incoming call arrives the personal
base station pages the mobile station over a paging channel and
thereafter sets up the required voice channel, with the paging and
voice channels both being in the second frequency band.
[0003] A problem that exists in presently specified systems relates
to the occurrence of a failure of the primary power to personal
base station, and/or an incoming telephone line failure. By
example, as presently specified the personal base station is
required to delay for some period of time (e.g., 15 minutes) after
an occurrence of a line failure before terminating the RF carrier.
As can be appreciated, during this time the mobile station may miss
any incoming paging messages and, thus, may not receive an
important incoming call.
[0004] Another problem that is not adequately addressed in
currently implemented or proposed systems relates to the case where
a conventional residential telephone shares the telephone line with
the personal base station. If the residential telephone is in use,
a call to the associated telephone number that is intended for the
mobile station will receive a busy signal.
OBJECTS OF THE INVENTION
[0005] It is thus a first object of this invention to provide an
improved method for operating a personal base station in
conjunction with a mobile station that overcomes the foregoing and
other problems.
[0006] It is another object of this invention to provide an
improved personal base station that overcomes the foregoing and
other problems.
SUMMARY OF THE INVENTION
[0007] The foregoing and other problems are overcome and the
objects of the invention are realized by methods and apparatus in
accordance with embodiments of this invention. In accordance with
the teaching of this invention a personal base station includes a
transceiver coupled to an antenna for conducting bidirectional
wireless communications with a mobile station; an interface to a
telephone line; and a controller that includes a circuit for
sensing that the telephone line is not available for use. The
controller is responsive to the telephone line not being available
for use for notifying a mobile station that the mobile station is
to obtain service from a public cellular communication system. This
may typically require the mobile station to register with the
public cellular communication system using a system-specified
messaging protocol.
[0008] In a preferred embodiment of this invention the sensing
circuit is operable to discriminate between a disconnection of the
telephone line and the use of the telephone line. In the first case
the disconnect message may be sent immediately, while in the latter
case the disconnect message may be sent after some predetermined
time delay.
[0009] In one embodiment the controller formats and transmits a
message to the mobile station for notifying the mobile station that
the mobile station is to register with the cellular communication
system, while in another embodiment the controller immediately
terminates a transmission of an RF carrier signal to the mobile
station for notifying the mobile station that the mobile station is
to register with the cellular communication system.
[0010] Methods for operating the personal base station are also
disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The above set forth and other features of the invention are
made more apparent in the ensuing Detailed Description of the
Invention when read in conjunction with the attached Drawings,
wherein:
[0012] FIG. 1 is a block diagram of a mobile station that is
suitable for use in implementing this invention;
[0013] FIG. 2 is an elevational view of the mobile station shown in
FIG. 1, and which further illustrates a public cellular
communication system to which the mobile station is bidirectionally
coupled through first wireless RF links, and which also shows a
personal base station to which the mobile station is
bidirectionally coupled through second wireless RF links;
[0014] FIG. 3 is block diagram of the personal base station of FIG.
2; and
[0015] FIG. 4 is a logic flow diagram that illustrates a method
executed by the personal base station of FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Reference is made to FIGS. 1 and 2 for illustrating a
wireless user terminal or mobile station 10, such as but not
limited to a cellular radiotelephone or a personal communicator,
that is suitable for practicing this invention. The mobile station
10 includes an antenna 12 for transmitting signals to and for
receiving signals from a base site or base station 30. The base
station 30 is a part of a public cellular network comprising a Base
Station/Mobile Switching Center/Interworking function (BMI) 32 that
includes a mobile switching center (MSC) 34. The MSC 34 provides a
connection to landline trunks such as the Public Switched Telephone
Network (PSTN) 36 when the mobile station 10 is involved in a
call.
[0017] The mobile station includes a modulator (MOD) 14A, a
transmitter 14, a receiver 16, a demodulator (DEMOD) 16A, and a
controller 18 that provides signals to and receives signals from
the transmitter 14 and receiver 16, respectively. These signals
include signalling information in accordance with the air interface
standard of the applicable cellular system, and also user speech
and/or user generated data.
[0018] It is understood that the controller 18 also includes the
circuitry required for implementing the audio and logic functions
of the mobile station. By example, the controller 18 may be
comprised of a digital signal processor device, a microprocessor
device, and various analog to digital converters, digital to analog
converters, and other support circuits. The control and signal
processing functions of the mobile station are allocated between
these devices according to their respective capabilities.
[0019] A user interface includes a conventional earphone or speaker
17, a conventional microphone 19, a display 20, and a user input
device, typically a keypad 22, all of which are coupled to the
controller 18. The keypad 22 includes the conventional numeric
(0-9) and related keys (#, *) 22a, and other keys 22b used for
operating the mobile station 10. These other keys 22b may include,
by example, a SEND key, various menu scrolling and soft keys, and a
PWR key. The mobile station 10 also includes a battery 26 for
powering the various circuits that are required to operate the
mobile station.
[0020] The mobile station 10 also includes various memories, shown
collectively as the memory 24, wherein are stored a plurality of
constants and variables that are used by the controller 18 during
the operation of the mobile station. For example, the memory 24
stores the values of various cellular system parameters and the
number assignment module (NAM). An operating program for
controlling the operation of controller 18 is also stored in the
memory 24 (typically in a ROM device). The memory 24 may also store
data, including user messages, that is received from the BMI 32
prior to the display of the messages to the user.
[0021] It should be appreciated that the mobile station 10 can be
capable of operating with one or more air interface standards,
modulation types, and access types. By example, the mobile station
may be capable of operating with any of a number of standards such
as IS-136, GSM and IS-95. Narrow-band AMPS (NAMPS), as well as
TACS, mobile stations may also benefit from the teaching of this
invention, as should dual or higher mode phones (e.g.,
digital/analog or TDMA/CDMA/analog phones). It should thus be clear
that the teaching of this invention is not to be construed to be
limited to any one particular type of mobile station or air
interface standard.
[0022] In the preferred embodiment of the invention the mobile
station 10 is also capable of operating with a personal base
station (PBS) 38 when in range of the PBS 38. Operation may occur
in a second band of frequencies that do not overlap the first band
of frequencies used for communication with the base station 30, or
in the same or an overlapping band of frequencies. The PBS 38 is
also connected to the PSTN 36 such that a call directed to the
mobile station 10, after the mobile station 10 has registered with
the PBS 38, will be directed to the PBS 38 for wireless connection
to the mobile station 10. One or more mobile stations 10 can be
serviced by the PBS 38.
[0023] Also shown in FIG. 2 is a capability to connect one or more
conventional telephone sets 40 to the incoming telephone line to
the PBS 38.
[0024] The PBS 38 is typically connected to the local power mains
(shown as AC and ACC), and may include a battery 41 for providing
temporary operating power in the event of a power loss or
failure.
[0025] Referring to FIG. 3, the PBS 38 includes a controller 38a,
such as a microprocessor and/or a digital signal processor, and a
transceiver comprised of a transmitter 38b, a receiver 38c and an
antenna 38d for communicating with the mobile station 10. The PBS
38 also includes a power supply 38e connected to the AC mains for
providing the required DC operating voltages (shown as +V and -V).
In this embodiment the power supply 38e generates a conventional
power loss or power down signal which is applied to the controller
38a to indicate a loss of AC power. The power down signal can be
connected to an interrupt input of the controller 38a or may be
connected to an input port for periodic sampling by the controller
38a. Controller 38a is also connected, through a suitable interface
circuit (INT) 38g to the incoming telephone line. A circuit such as
a comparator 38f can also be connected to the telephone line for
providing a line status signal to the controller 38a. In this case,
a reference voltage (V.sub.REF) is also connected to the comparator
38f. By example, when the voltage potential on the telephone line
drops below the reference voltage, the line status signal is
asserted to the controller 38a. Depending on the magnitude of the
reference voltage, the line status signal can indicate either that
the telephone line is disconnected or, for the case where the
conventional telephone 40 is connected, that the conventional
telephone 40 is off-hook and that the telephone line is in use.
[0026] It is also within the scope of this invention for the
controller 38a to periodically verify the operation of the
controlling telephone switch that is connected to the telephone
line. If the controlling switch is found to be non-functional, then
the disconnect message is sent, preferably immediately, to the
mobile station 10. The controller 38a can verify the operation of
the switch by periodically generating an off-hook condition, and
then detecting the presence of a dial tone from the switch. If the
dial tone is received, it is assumed that the switch is functional,
and the controller 38a then generates the on-hook condition.
[0027] Referring now to FIG. 4, the controller 38a of FIG. 3
operates in a loop to monitor power and the telephone line status.
At Block A the PBS 38 monitors the primary power as indicated by,
for example, the state of the power down signal. At Block B a
determination is made if the primary power is lost. If yes, and for
a case where the controller 38a does not have adequate battery
backup or has been operating for some period of time using the
battery backup, control passes to Block F wherein, in accordance
with this invention, the PBS 38 sends as message to the mobile
station 10 to disconnect from the PBS 38 and register with the base
station 30 of the serving cellular network. If no at Block B,
control passes to Block C where the PBS 38 monitors the phone line
connection as indicated by the line status signal output from the
comparator 38f (and/or by detecting the dial tone while temporarily
going off-hook). At Block D the PBS 38 determines if the phone line
is disconnected or otherwise non-functional. If yes, control passes
to Block F to send the disconnect message to the mobile station 10.
The message may be sent immediately or after some delay.
Immediately sending the disconnect message or indication, in the
context of this invention, implies that the message or indication
is sent without any preprogrammed delay. For the case where the
controller 38a is able to discriminate between the phone line being
disconnected and the use of the phone line by the attached
telephone 40, a separate determination is made at Block E if the
phone line is in use. If yes, the PBS 38 sends the disconnect
message to the mobile station. Assuming that the determinations at
Blocks D and E are both no, control passes back to Block A to
continue monitoring the primary power and the state of the phone
line.
[0028] It can be appreciated that the method described in FIG. 4
eliminates the possibility that the mobile station 10 may miss an
incoming call during a time that the PBS 38 is unpowered or when
the incoming telephone line is not available for use.
[0029] Having registered with the base station 30, any incoming
calls to the mobile station 10 will be routed by the MSC 34 through
the base station 30, and not through the PBS 38.
[0030] It is within the scope of this invention for the mobile
station 10 to periodically attempt to register with the PBS 38
after it has been instructed to deregister and register with the
BMI 32. In this manner the mobile station 10 is enabled to once
more obtain service through the PBS 38 after the power loss
condition or the telephone line unavailability condition has been
corrected or no longer exists.
[0031] It is also within the scope of this invention for the PBS 38
to delay sending the disconnect message when the determination at
Block E of FIG. 4 indicates that the telephone line is in use. By
example, having detected that another telephone is using the phone
line, the controller 38a may delay for some predetermined period of
time (e.g., one minute) and then re-execute Block E. Only if the
phone line is still in use does the controller 38a enter Block F to
send the message to the mobile station 10 instructing the mobile
station to deregister and register instead with the cellular
system. The use of the time delay in this case avoids the
possibility of causing frequent deregistrations due to short
incoming or outgoing phone calls being made to or from the
telephone 40.
[0032] Although described in the context of preferred embodiments,
it should be realized that a number of modifications to these
teachings may occur to one skilled in the art. By example, one
embodiment of the invention described in Block F of FIG. 4
immediately sends a message to the mobile station 10 to instruct
the mobile station to enter the cellular mode. However, this can
also be achieved by the PBS 38 terminating the transmission of an
RF carrier to the mobile station 10. In this case the mobile
station 10 senses the loss of the RF carrier, and then
automatically sends a registration message to the base station 30.
Of course, both techniques could be used (e.g., the PBS 38 sends a
specific disconnect message to the mobile station 10, followed by a
termination of the transmission of the RF carrier). A subsequent
transmission of the RF carrier by the PBS 38 can also be sensed by
the mobile station 10 and, assuming that the mobile station 10 is
not involved in a call, can result in the mobile station
deregistering from the BMI 32 and once more registering with the
PBS 38.
[0033] Thus, while the invention has been particularly shown and
described with respect to preferred embodiments thereof, it will be
understood by those skilled in the art that changes in form and
details may be made therein without departing from the scope and
spirit of the invention.
* * * * *