U.S. patent application number 13/350292 was filed with the patent office on 2012-05-10 for adaptive data delivery.
This patent application is currently assigned to RESEARCH IN MOTION LIMITED. Invention is credited to Allan David Lewis, Gary Phillip Mousseau.
Application Number | 20120113854 13/350292 |
Document ID | / |
Family ID | 37893811 |
Filed Date | 2012-05-10 |
United States Patent
Application |
20120113854 |
Kind Code |
A1 |
Lewis; Allan David ; et
al. |
May 10, 2012 |
Adaptive Data Delivery
Abstract
Techniques for use in delivering data from a host service to a
mobile device operative in a wireless network are disclosed. The
host service is configured to maintain in a host memory an
availability status indicative of the availability of the mobile
device in the wireless network. A router receives an indication
signal from the mobile device within a predetermined interval. The
indication signal indicates one or more functional states or
parameter levels of the mobile device. When the one or more
functional states or parameter levels of the indication signal are
indicative of availability, and a cached availability status in
cache memory of the router equals to unavailable, the router
changes the cached availability status from unavailable to
available and transmits the changed availability status from the
router to the host service for setting the availability status at
the host service.
Inventors: |
Lewis; Allan David; (New
Dundee, CA) ; Mousseau; Gary Phillip; (Waterloo,
CA) |
Assignee: |
RESEARCH IN MOTION LIMITED
Waterloo
CA
|
Family ID: |
37893811 |
Appl. No.: |
13/350292 |
Filed: |
January 13, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11236363 |
Sep 27, 2005 |
8121069 |
|
|
13350292 |
|
|
|
|
Current U.S.
Class: |
370/252 ;
370/254 |
Current CPC
Class: |
H04W 4/12 20130101 |
Class at
Publication: |
370/252 ;
370/254 |
International
Class: |
H04W 84/00 20090101
H04W084/00; H04W 40/00 20090101 H04W040/00; H04W 24/00 20090101
H04W024/00; H04L 12/28 20060101 H04L012/28 |
Claims
1-20. (canceled)
21. A method in a router system configured to route messages from a
host service to a wireless mobile device via a wireless network,
the host service being configured to provide a service for the
wireless mobile device, the method in the router system comprising:
receiving from the host service a message associated with the
service for the wireless mobile device, and forwarding the message
to the wireless mobile device via the wireless network; receiving
an indication signal from the wireless mobile device via the
wireless network, the indication signal including an indication
that indicates unavailability to receive the message associated
with the service; determining and setting in memory of the router
system an unavailability status associated with the wireless mobile
device based on the received indication signal; and providing to
the host service the unavailability status associated the wireless
mobile device, for indicating to the host service to not send
further messages associated with the service to the router system
for the wireless mobile device.
22. The method of claim 21, further comprising: receiving a request
from the host service; and in response to the request, sending the
unavailability status associated with the wireless mobile device to
the host service.
23. The method of claim 21, further comprising: determining the
unavailability status associated with the wireless mobile device
based on repeated unsuccessful attempts to transmit messages
associated with the service to the wireless mobile device.
24. The method of claim 21, wherein the router system is configured
to communicate with a plurality of host services which are
configured to provide a plurality of services for a plurality of
wireless mobile devices.
25. The method of claim 21, wherein the router system is configured
to route messages which comprise messages for electronic mail
(e-mail).
26. The method of claim 21, wherein the wireless mobile device
comprises a cellular telephone.
27. The method of claim 21, wherein the indication comprises a
functional state of the wireless mobile device.
28. The method of claim 21, wherein the indication comprises a
parameter of the wireless mobile device.
29. The method of claim 21, wherein the indication indicates a
status of a battery of the wireless mobile device or a status of
available memory space in the wireless mobile device.
30. The method of claim 21, wherein the router system is external
to the wireless network and in communication with the host service
over a connection via a communication network comprising the
Internet.
31. A router system, comprising: a receiver configured to receive
from a host service a message associated with a service for a
wireless mobile device; a transmitter configured to forward the'
message associated with the service to the wireless mobile device
via a wireless network; the receiver being further configured to
receive an indication signal from the wireless mobile device via
the wireless network, the indication signal including an indication
that indicates unavailability to receive the message associated
with the service; the router system being further configured to
determine and set in its memory an unavailability status associated
with the wireless mobile device based on the received indication
signal; and the transmitter being further configured to provide to
the host service the unavailability status associated the wireless
mobile device, for indicating to the host service to not send
further messages associated with the service to the router system
for the wireless mobile device.
33. The router system of claim 31, further comprising: the receiver
being further configured to receive a request from the host
service; and the transmitter being further configured to send, to
the host server in response to the request, the unavailability
status associated with the wireless mobile device.
34. The router system of claim 31, which is further configured to
determine the unavailability status associated with the wireless
mobile device based on repeated unsuccessful attempts to transmit
messages associated with the service to the wireless mobile
device.
35. The router system of claim 31, which is further configured to
communicate with a plurality of host services which are configured
to provide a plurality of services for a plurality of wireless
mobile devices.
36. The router system of claim 31, which is further configured to
route messages which comprise messages for electronic mail
(e-mail).
37. The router system of claim 31, which is configured to
communicate with a wireless mobile device comprising a cellular
telephone.
38. The router system of claim 31, wherein the indication comprises
a functional state of the wireless mobile device.
39. The router system of claim 31, wherein the indication comprises
a parameter of the wireless mobile device.
40. The router system of claim 31, wherein the indication indicates
a status of a battery of the wireless mobile device or a status of
available memory space in the wireless mobile device.
41. The router system of claim 31, which is external to the
wireless network and in communication with the host service over a
connection via a communication network comprising the Internet.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation of and claims
priority to U.S. non-provisional patent application having
application Ser. No. 11/236,363 and filing date of 27 Sep. 2005,
now U.S. Pat. No. ______, which is hereby incorporated by reference
herein.
FIELD OF THE INVENTION
[0002] The present invention generally relates to a wireless
communication system, and more specifically to a system and a
method for adaptively delivering data to a wireless mobile device
based upon the availability of the wireless mobile communication
device in the wireless communication system.
BACKGROUND OF THE INVENTION
[0003] In a wireless communication system designed to deliver data
to a wireless mobile communication device ("mobile device") such as
a cellular telephone, a two-way pager, a wireless communication
capable personal digital assistant ("PDA"), and other similar
device, there are several main components in the wireless
communication system. A host service, which provides services such
as e-mail, calendar, and Internet web browsing, holds the data to
be delivered to the mobile device. The host service is coupled to a
router, which couples the host service and a wireless network that
is designed to communicate with the mobile device. To make a timely
delivery of the data, the host service forwards the data for the
mobile device to the router when the data becomes available. The
router then forwards the data to the wireless network, which
transmits the data to the mobile device. If the mobile device fails
to receive the data, the router queues the data and re-forwards the
data to the wireless network, which re-transmits the data to the
mobile device. This process continues until the. mobile device
receives the data and acknowledges the reception or the process
times out after a predetermined time period. While the data is
being transmitted and queued, another data may become available for
the mobile device in the host service, and may be forwarded to the
router. The other data is then forwarded to the wireless network
and is transmitted to the mobile device, but fails to be received
by the mobile device. The host service continues to transmit more
data, as they become available, to the router without the knowledge
of the mobile device thereby wasting the host service resources,
undeliverable data continues to accumulate in the router wasting
the router resources, and the capacity in the wireless network is
wasted by repeatedly transmitting the data without having any
indication that the delivery of the data will be successful.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is an exemplary environment in which a wireless
communication system in accordance with at least one of the
preferred embodiments may be practiced;
[0005] FIG. 2 is an exemplary state diagram of a host service in
accordance with at least one of the preferred embodiments;
[0006] FIG. 3 is an exemplary sequence diagram illustrating a
sequence of adaptive delivery of data from a host service to a
wireless mobile communication device in a wireless communication
system in accordance with at least one of the preferred
embodiments;
[0007] FIG. 4 is an exemplary flowchart illustrating a process of
adaptive delivery of data to a wireless mobile communication device
in a wireless communication system in accordance with at least one
of the preferred embodiments;
[0008] FIG. 5 is an exemplary flowchart further illustrating the
process for setting the availability status at the host service
based upon the cached availability status at the wireless router
system in accordance with at least one of the preferred
embodiments;
[0009] FIG. 6 is an exemplary flowchart further illustrating the
process for determining whether to re-transmit the data from the
wireless router system to the mobile device in accordance with at
least one of the preferred embodiments; and
[0010] FIG. 7 is an exemplary block diagram of a wireless
communication system configured to adaptively deliver data to a
wireless mobile communication device in the wireless communication
system in accordance with at least one of the preferred
embodiments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] A wireless communication system, comprising a host service,
a wireless router system coupled to the host service, a wireless
network coupling the wireless router system and a wireless mobile
communication device ("mobile device"), adaptively delivers data to
the mobile device in the wireless communication system. When the
host service has data to be delivered to the mobile device, it
first determines the availability status of the mobile device at
the host service. The availability status may be based upon its
previous data delivery to the mobile device, a cached availability
status at the wireless router system, which may check whether the
mobile device is registered in the wireless network. The wireless
network may be, but not limited to, a cellular telephone network, a
two-way paging network, a short range wireless network such as
Bluetooth.TM. and IEEE 802.11 compliant network, and others alike,
through which the mobile device is accessible by the wireless
router system. If the mobile device is determined to be available,
then the host service transmits the data to the wireless router
system, which delivers the data through the wireless network to the
mobile device. However, if the mobile device is determined to be
unavailable, then the host service queues the data but does not
send the data until the mobile device is re-determined to be
available, thereby avoiding unnecessary transmission of the data
directed to the mobile device.
[0012] FIG. 1 is an exemplary wireless communication system 100 in
which a wireless communication system in accordance with at least
one of the preferred embodiments may be practiced. The exemplary
wireless communication system 100 includes a plurality of host
services (three shown, 102, 104, and 106), each of which may have a
plurality of services such as, but not limited to, e-mail,
calendar, Internet web browser, and other applications, available
to their subscribers. The host services 102, 104, and 106 are
connected to a communication network 108 such as Internet, which
connects to a wireless router system 110 allowing communication
between the host services 102, 104, and 106 and the wireless router
110. The wireless router system 110 may also be connected to a host
service, such as a local service 112, without the communication
network 108. The wireless router system 110 is connected to a
plurality of wireless networks (three shown, 114, 116, and 118),
each of which may support a plurality of mobile devices (one in
each wireless network is shown, 120, 122, and 124). The wireless
networks 114, 116, and 118 may be a cellular telephone network, a
two-way paging network, a short range wireless network such as
Bluetooth.TM. and IEEE 802.11 compliant network, and others alike,
and the mobile devices 120, 122, and 124 are device compatible with
the corresponding wireless network.
[0013] FIG. 2 is an exemplary state diagram 200 of a host service
in accordance with at least one of the preferred embodiments. In
this example, the states of the host service 102 attempting to
deliver data to the mobile device 120 are illustrated. In state
202, the host service 102 checks whether the state of the
availability status of the mobile device 120 is known upon
generating the data to be delivered to the mobile device 120. The
data may be generated internally by the host service 102 or may be
generated in response to the host service 102 receiving
corresponding data from another source. For example, the data may
be a message from the host service 102 regarding a service that the
host service provides to the mobile device 120 such as Internet web
browsing, music downloads, news service, or any other host service
specific services originating from the host service 102, or the
data may be an e-mail message, sent from an external source and
received by the host service 102, to be delivered to the mobile
device 120. The availability status of the mobile device 120 may
be, or become, unknown, for example, when the host service 120
initially generates the data having no prior knowledge of the
availability of the mobile device 120, a previously stored
availability status becomes stale or too old, or the host service
encounters a reset condition such as losing connection to the
wireless router system 110. If the host service 102 has data for
the mobile device 120 and the availability status of in the mobile
device 120 is unknown, the host service 102 requests, and receives
from, the wireless router system 110 the current status of the
mobile device 120 in the wireless router system 110 in state 204,
and the availability status of in the mobile device 120 becomes
known in state 206. The host service 102 may also receive an
updated availability status whenever the availability status at the
wireless router system 110 changes. If the host service 102 has
data for the mobile device 120 and the availability status of in
the mobile device 120 is known, in state 206, the host service 102
determines whether mobile device 120 is available based upon the
known availability status. In state 208 where the known
availability status of the mobile device 120 equals available, the
host service forwards the data to the wireless router system 110.
If the known availability status of the mobile device 120 equals
unavailable available in state 210, the host service 102 queues the
data and returns to state 202.
[0014] FIG. 3 is an exemplary sequence diagram 300 illustrating a
sequence of adaptive delivery of data from the host service 102 to
the mobile device 120 in the wireless communication system 100 in
accordance with at least one of the preferred embodiments. When the
host service 102 generates data for the mobile device 120 having no
known state of the availability status of the mobile device 120,
the host service 102 requests the availability status of the mobile
device 120 at the wireless router system 110 from the wireless
router system 110. In this example, the wireless router system
returns the `unavailable` status to the host service 102, and the
data is queued in the host service 102. The host service 102 now
has a known availability status of the mobile device 120, which is
`unavailable.` A while later, the wireless router system 110
receives a `keep-alive` signal from the mobile device 120,
indicating that the mobile device 120 is now available to receive
data in the wireless communication system 100 through the wireless
network 114, and has an effect of the mobile device 120
establishing a virtual connection with the wireless router system
110. The wireless router system now sends the `available` status to
the host service 102, and the host service 102 forwards the data to
the wireless router system 110. The host service 102 now has a
known availability status of the mobile device 120, which is
`available." The wireless router system now transmits the data to
the mobile device 120 through the wireless network 114. When the
host service 102 generates subsequent set of data for the mobile
device 120, the availability status of the mobile device 120 is
already know as `available` and the host service 102 forwards the
subsequent set of data to the wireless router system 114. The
mobile device 120 is designed to transmit the `keep-alive` signal
at a predetermined time period such as every 15 minutes as shown in
FIG. 3, and the wireless router system 110 keeps the current
availability status of `available` as long as the wireless router
system 110 receives the keep-alive signal at the predetermined time
period interval. FIG. 3 shows the wireless router system 110
receiving two consecutive keep-alive signals at the predetermined
time period interval after transmitting the subsequent set of data.
Because the wireless router system 110 has received the keep-alive
signals at the predetermined time period interval, the availability
status of the mobile device 120 is unchanged as available, and the
wireless router system does not transmit an updated availability
status to the host service 102. However, as shown in FIG. 3, the
wireless router system 110 fails to receive the keep-alive signal
from the mobile device 120 during the third expected interval. The
availability status of the mobile device 120 is now changed to
`unavailable` and the wireless router system 110 transmits the
updated availability status of `unavailable` to the host service
102. The host service 102 then updates the availability status to
`unavailable` such that if any subsequent data for the mobile
device 120 is generated while the availability status is
`unavailable,` the host service 102 queues such data. A while
later, the wireless router system 110 again receives the keep-alive
signal from the mobile device 120, and updates the availability
status to `available.` Because there has been a change in the
availability status, the wireless router system transmits the
updated availability status of `available` the host service
102.
[0015] FIG. 4 is an exemplary flowchart 400 illustrating a process
of adaptive delivery of data to a mobile device in the wireless
communication system 100 in accordance with at least one of the
preferred embodiments. For the purpose of the illustration, the
data to be delivered resides in the host service 102, and the data
is to be delivered to the mobile device 120. As previously
explained, a host service may be connected to the wireless router
system 110 with or without the communication network 108 such as
Internet. The process begins in block 402 and data to be delivered
to the mobile device 120 is generated in the host service 102 in
block 404. The data may be generated internally by the host service
102 or may be generated in response to the host service receiving
corresponding data from another source. For example, the data may
be a message from the host service 102 regarding a service that the
host service 102 provides to the mobile device 120 such as Internet
web browsing, music downloads, news service, or any other host
service specific services originating from the host service 102, or
the data may be an e-mail message, which is sent from an external
source and received by the host service 102, to be delivered to the
mobile device 120. Initially, such as the very first time the host
service 102 is to deliver the data to the mobile device 120, the
host service 102 has no knowledge of the availability of the mobile
device 120 in the wireless communication system 100. Instead of
assuming that the mobile device 120 is available to receive the
data and transmitting the data to the mobile device 120, whether
the availability status of the mobile device 120 is known at the
host service 102 is determined in block 406. Whether the
availability status of the mobile device 120 is known at the host
service 120 in block 406 may be based upon a stored availability
status at the host service 102. The availability status of the
mobile device 120 may be deemed to be unknown if there is no stored
availability status of the mobile device 120 such as when the
process is first initiated and there is no prior stored
availability status of the mobile device 120 at the host service
102. Even if the stored availability status of the mobile device
120 is known, it may be deemed to be unknown if the stored
availability status becomes stale or too old. The stored
availability status may also become unknown if a connection between
the host service 102 and the wireless router system 110 is
lost.
[0016] If the availability status of the mobile device 120 is
determined to be known in block 406, the process advances to block
408. However, if the availability status of the mobile device 120
is determined to be unknown in block 406, the availability status
of the mobile device 120 at the host service 102 is set equal to a
cashed availability status of the mobile device 120 at the wireless
router system 110 in block 410. The availability status of the
mobile device 120 at the host service 102 now becomes known, and
the process advances to block 408. In block 408, the value of the
known availability status of the mobile device 120, i.e., available
or unavailable, at the host service 102 is determined. For example,
the mobile device 120 may be determined to be unavailable because
the mobile device 120 is outside of a coverage area provided by the
wireless network 114 or is turned off, or the wireless network 114
is unavailable or unable to transmit the message to the mobile
device 120.
[0017] If the known availability status is determined to equal
unavailable in block 408, then the data becomes pending and is
queued in the host service 102 in block 412, and the process loops
back to block 406. The pending data is only queued in the host
service 102 only if the pending data to be queued is new, and is
not re-queued if the pending data has been already queued in a
previous iteration. Queuing of the pending data at the host service
102 is helpful in preserving resources in the case of recovery from
a system related failure such as a lost connection to the wireless
router 110. If the known availability status is determined to equal
available in block 408, then the data is transmitted from the host
service 102 to the wireless router system 110 in block 414. The
data is then transmitted from the wireless router system 110 to the
mobile device 120 through the wireless network 114 in block 416. In
block 418, whether the data transmission to the mobile device 120
has been successful is determined. The successful data transmission
from the wireless router system 110 to the mobile device 120 may be
determined based upon a confirmation signal transmitted from the
mobile device 120 in response to successfully receiving the data.
For example, there may be a predetermined time period within which
the confirmation signal from the mobile device 120 is expected
after the data is transmitted from the wireless router system 110.
The availability status of the mobile device 120 at the wireless
router system 110 may be re-determining upon the confirmation
signal, and the cached availability status at the wireless router
system 110 may then be updated with the re-determined availability
status. If the data transmission is determined to be successful in
block 418, then the process loops back to block 404, and waits for
next data. However, if the data transmission is determined to be
unsuccessful in block 418, then whether the data should be
re-transmitted to the mobile device 120 is determined in block 420.
If the data is determined to be re-transmitted, then the process
loops back to block 416 where the data is re-transmitted to the
mobile device 120. If the data is determined not to be
re-transmitted in block 420, then the process advances to block 412
where the data is queued at the host service 102, and the process
from block 406 is repeated. However, if the indication signal from
the mobile device 120 is received by the wireless router system 110
after the data has been queued in the host service 102, the cached
availability status of the mobile device 120 at the wireless router
system 110 is updated to "available". The updated cached
availability status of "available" is transmitted to the host
service 102 from the wireless router system 110, making the
available status at the host service 102 in block 408 equal to
available. At this time, the pending data, which was previously
queued, becomes ready to be delivered to the mobile device 120, and
is un-queued. Then the process for determining successful
transmission of data to the mobile device 120 from the host service
102, previously described in blocks 414, 416, 418 and 420, is
followed. If the transmission of the queued data to the mobile
device 120 is determined to be successful in block 418, then the
previously queued data, which has now been successfully delivered
to the mobile device 120, is purged in block 422. The process then
advances to block 404, and waits for next data.
[0018] FIG. 5 is an exemplary flowchart further illustrating the
process of block 410 for setting the availability status at the
host service 102 based upon the cached availability status at the
wireless router system 110 in accordance with at least one of the
preferred embodiments. The cached availability status of the mobile
device 120 at the wireless router system 110 may be based upon an
indication signal transmitted from the mobile device 120. The
indication signal, sometimes referred as a "heart beat" or a
"keep-alive" signal, may be periodically transmitted by the mobile
device 120, and if it is received by the wireless router system
110, it generally indicates that the mobile device 120 is
available, or in a coverage area of the wireless network 114, and
has an effect of the mobile device 120 establishing a virtual
connection with the wireless router system 110. The indication
signal, however, may also indicate unavailability of the mobile
device 120 in the wireless communication system 100. For example,
the mobile device 120 may have a very limited memory space left and
is unable to receive further data, or due to its low battery
status, its wireless communication ability may begin to shut down
to conserve the battery power. The indication signal may include a
plurality of functionality states of the wireless device 120 such
as, but not limited to, the available memory space, battery status,
and received signal strength indicator ("RSSI"). In this example
for simplicity, the indication signal from the mobile device 120 is
used to illustrate that the mobile device 120 is available in the
wireless communication system 100.
[0019] In block 502, whether the indication signal from the mobile
device 120 is received at the wireless router system 110 is
determined. If it is determined that the indication signal has been
received, then the cached availability status of the mobile device
120 at the wireless router system 110 is set to be "available" in
block 504. If the cached availability status had previously been
set to "unavailable" then it is re-set to be "available" in block
504. The process then advances to block 506. If the indication
signal is determined not to have been received, then whether the
indication signal periodic interval has elapsed is determined in
block 508. If the indication signal periodic interval is determined
not to have elapsed, then the process loops back to block 502. As
long as the indication signal is received periodically at, or
within, the indication signal periodic interval, the cached
availability status of the mobile device 120 is kept equal to
available. However, if the indication signal periodic interval is
determined to have elapsed in block 508, then the cached
availability status of the mobile device 120 at the wireless router
system 120 is set to be "unavailable" in block 510. If the cached
availability status had previously been set to "available" then it
is re-set to be "unavailable" in block 510. The process then
advances to block 506. In block 506, the cached availability status
of the mobile device 120, either available or unavailable, at the
wireless router system 110 is provided to the host service 102,
setting the availability status to be known at the host service
102.
[0020] FIG. 6 is an exemplary flowchart further illustrating the
process of block 420 for determining whether to re-transmit the
data from the wireless router system 110 to the mobile device 120
as a result of the data transmission being determined to be
unsuccessful in block 418 in accordance with at least one of the
preferred embodiments. In block 602, whether predetermined re-try
logic has been exhausted is determined. The predetermined re-try
logic may include, and may be any combination of, a maximum number
of re-transmissions, a maximum overall time of re-transmissions,
and a maximum back-off time. When implementing a delivery system in
a wireless network, it is common to use a progressive back-off
method for re-transmitting data to a destination device. If the
re-try logic has not been exhausted, then the process loops back to
block 416 where the data is re-transmitted from the wireless router
system 110 to the mobile device 120. However, if the re-try logic
is exhausted, meaning that no confirmation signal has been
received, the mobile device 120 is deemed to be unavailable and the
cached availability status at the wireless router system 110 is
updated to "unavailable" in block 604. The updated cached
availability status is communicated from the wireless router system
110 to the host service 102 in block 606, and the availability
status of the mobile device 120 at the host service 102 is updated
to "unavailable." The process then advances to block 412 where the
data is queued in the host service 102.
[0021] Because it takes a finite amount of time between when the
mobile device 120 is determined to be available to receive the
generated data and when the data is transmitted from the wireless
router system 110 to the mobile device 120, there may be a change
in the availability status of the mobile device 120 during that
time. To address this concern, additional steps may be provided
between block 414, in which the data is transmitted from the host
service 102 to the wireless router system 110, and block 416, in
which data is transmitted from the wireless router system 110 to
the mobile device 120. For example, instead of solely relying on
the availability status of the mobile device 120 at the host
service 102, the availability status of the mobile device 120 may
be evaluated at the wireless router system 110 when the data is
transmitted from the host service 102 to the wireless router
service 110 based upon the current cached availability status at
the wireless router system 110. The decision whether to further
transmit the data from the wireless router system 110 to the mobile
device 120 then may be made based upon the evaluated cached
availability status of the mobile device 120. If the evaluated
cached availability status is "available", then the data is
transmitted from the wireless router system 110 to the mobile
device 120 in block 416, and the process previously described is
followed. However, if the evaluated cached availability status is
"unavailable", then the availability status of the mobile device
120 at the host service 102 is updated to "unavailable", and the
data is queued at the host service 102 in block 412.
[0022] FIG. 7 is an exemplary block diagram of a wireless
communication system 700 configured to adaptively deliver data to a
wireless mobile communication device ("mobile device") in the
wireless communication system 700 in accordance with at least one
of the preferred embodiments. Although the wireless communication
system 700 may include a plurality of host services, wireless
networks, and wireless devices as previously shown in FIG. 1, the
wireless communication system 700 in FIG. 7 is shown with a reduced
number of elements for simplicity. The wireless communication
system 700 includes a mobile device 702, and a host service 704,
which includes a data generator 706 configured to generate data to
be delivered to the mobile device 702. The data generator 706 may
generate the data to be delivered to the mobile device 702 in
response to receiving corresponding data. The host service 704 also
includes a status evaluator 708 configured to determine whether an
availability status of the wireless device 702 in the wireless
communication system 700 is known. The host service 704 is coupled
to a wireless router system 710, and has a host transmitter 712
that transmits the data to the wireless router system 710 if the
known availability status of the mobile device 702 equals
available. The host service 704 also has a host memory 714, and
queues the data in the host memory 714 if the known availability
status equals unavailable. The host service 704 only queues the
data in the host memory 714 only if the data to be queued is new
and does not re-queue the data that has already been queued in a
previous iteration. The host service 704 may be coupled to the
wireless router system 710 through a communication network 716,
which may be a wide area network such as Internet, and is
configured to allow communication between the host service 704 and
the wireless router system 710.
[0023] The wireless router system 710 includes a cache memory 718
configured to cache the availability status of the mobile device
702 in the wireless communication system 700. The wireless router
system 710 also includes a router receiver 720 configured to
receive the data from the host service 704, and a router
transmitter 722 configured to transmit the data to a wireless
communication network 724. The wireless communication network 724
is coupled to both the wireless router system 710 and the mobile
device 702, and is configured to receive the data from the wireless
router system 710 and to transmit the data to the mobile device
702. The wireless communication network 724 may be a cellular
telephone network, a two-way paging network, a short range wireless
network such as Bluetooth.TM. and IEEE 802.11 compliant network,
and others alike, which is compatible with the mobile device
702.
[0024] If the status evaluator 708 determines that the availability
status of the mobile device 702 in the wireless communication
system 700 is not known, then the status evaluator 708 sets the
cached availability status stored in the cache memory 718 as the
known availability status. If the known availability status equals
available, the host transmitter 712 transmits the data to the
wireless router system 710. If the known availability status equals
unavailable, the host service 704 queues the data in the host
memory 714. The data generator 706 may treat the queued data in the
host memory 714 as generated data.
[0025] The status evaluator 708 may also determine the availability
status of the mobile device 702 based upon a stored availability
status at the host service 704, for example in the host memory 714.
The status evaluator 708 may determine that the availability status
at the host service 704 is unknown if there is no stored
availability status, or if a predetermined time period has passed
since the availability status has been stored, meaning the stored
availability status is too old. The status evaluator 708 may also
determine that the availability status at the host service 704 is
unknown if a connection between the host service 704 and the
wireless router system 710 is lost.
[0026] At the wireless router system 710, the cached availability
status of the wireless device 702 may be based upon an indication
signal from the wireless device 702. The indication signal may
sometimes be referred as a "heart beat" or a "keep-alive" signal.
If the wireless router system 710 receives the indication signal,
for example by the router receiver 720, it indicates that the
wireless device 702 is available, or in a coverage area of the
wireless network 724. The indication signal may include various
states of the wireless device 702 in addition to an indication
being available to receive the data from the host service 704 such
as, but not limited to, current location based on a Global
Positioning System ("GPS") data, battery status, memory status,
transmit power level, receive signal strength indicator ("RSSI")
value, and other parameters. If the wireless router system 710
receives the indication signal from the mobile device 702, the
wireless router system 710 makes the cached availability status of
the wireless device 702 equal to available in the cache memory 718.
If the wireless router system 701 fails to receive the indication
signal from the wireless device 702, the wireless router system 710
makes the cached availability status of the wireless device 702
equal to unavailable in the cache memory 718.
[0027] The wireless device 702 may transmit the indication signal
periodically, and the wireless router system 710 may keep the
cached availability status in the cache memory 718 equal to
available if the wireless router system 710 receives the indication
signal from the mobile device 702 periodically at a predetermined
interval. Conversely, if the wireless router system 710 fails to
receive the indication signal from the mobile device 702
periodically at a predetermined interval, the wireless router
system may change the cached availability status to unavailable,
and transmit the changed cached availability status to the host
service 704, for example, by the router transmitter 722, causing
the status evaluator 708 to update the known availability status to
unavailable. The cached availability status may be changed back to
available when wireless router system 710 once again receives the
indication signal from the mobile device 702, and may transmit the
changed cached availability status, now back to available, to the
host service 704. If there is queued data at the host service 704
at this time, then the host transmitter 712 transmits the queued
data to the wireless router system 710.
[0028] After the router transmitter 722 transmits the data to the
mobile device 702, the wireless router system 710 may determine
whether the data transmission to the wireless device 702 has been
successful based upon a confirmation signal transmitted from the
wireless device 702 in response to successfully receiving the data.
The wireless router system 710 may then re-determine the
availability status of the wireless device 702 based upon the
confirmation signal, and update the cached availability status in
the cache memory 718 with the re-determined availability status.
The wireless router system 710 may be configured to receive the
confirmation signal within a predetermined time period after
transmission of the data to the mobile device 702, and to
re-transmit the data to the mobile device 702 until predetermined
re-try logic is exhausted if the wireless router system 710 fails
to receive the confirmation signal within the predetermined time
period. The predetermined re-try logic may one or any combination
of a maximum number of re-transmissions, a maximum overall time of
re-transmissions, and a maximum back-off time. When implementing a
delivery system in a wireless network, it is common to use a
progressive back-off method for re-transmitting data to a
destination device. If the wireless router system 710 fails to
receive the confirmation signal after the predetermined re-try
logic is exhausted, then the wireless router system 710 updates the
cached availability status in the cache memory 718 of the mobile
device 702 to unavailable. The wireless router system 710 then
transmits the updated cached availability status to the host
service 704, which updates the availability status of the mobile
device 702 to unavailable and to queue the data in the host memory
714. However, if the indication signal from the mobile device 702
is received by the wireless router system 710 after the data has
been queued in the host memory 714, the cached availability status
of the mobile device 702 at the wireless router system 710 is
updated to "available". The updated cached availability status of
"available" is transmitted to the host service 704 from the
wireless router system 710, making the status evaluator 708 to set
the availability status at the host service 702 to equal available.
The wireless router system 710 then determines whether the
transmission of queued data to the mobile device 702 has been
successful as previously described. If the wireless router system
710 determines that the transmission of the queued data to the
mobile device 702 has been successful, then the host service 704
purges the previously queued data, which has now been successfully
delivered to the mobile device 702, from the host memory 714.
[0029] Because it takes a finite amount of time between when the
wireless router system 710 determines that the mobile device 702 is
available and when the router receiver 720 receives the data from
the host service 704, it is possible for the mobile device 702 to
have changed the availability status during that time. To address
this possibility, the wireless router system 710 be configured to
evaluate the cached availability status of the mobile device 702
after receiving the data from the host service 704 but before
transmitting the data to the mobile network 724. If the evaluated
cached availability status is equal to available, then the router
transmitter transmits the data to the mobile device 702 through the
wireless communication network 724. The determination of a
successful reception of the data by the mobile device 702,
re-transmission of the data, updating of the cached availability
status and availability status at the host service 704, and queuing
of the data may be performed as previously described.
[0030] While the preferred embodiments of the invention have been
illustrated and described, it is to be understood that the
invention is not so limited. Numerous modifications, changes,
variations, substitutions and equivalents will occur to those
skilled in the art without departing from the spirit and scope of
the present invention as defined by the appended claims.
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