U.S. patent application number 11/807290 was filed with the patent office on 2007-10-11 for system and method for full wireless synchronization of a data processing apparatus with a messaging service.
Invention is credited to Michael Belshe, Mike Bennett, Roger Collins, John Friend.
Application Number | 20070239898 11/807290 |
Document ID | / |
Family ID | 30002541 |
Filed Date | 2007-10-11 |
United States Patent
Application |
20070239898 |
Kind Code |
A1 |
Friend; John ; et
al. |
October 11, 2007 |
System and method for full wireless synchronization of a data
processing apparatus with a messaging service
Abstract
A system is disclosed in which a data processing device is
completely synchronized with a messaging service. One embodiment of
the system comprises a wireless data processing device; a messaging
service to maintain messages and other information on behalf of a
user; and synchronization logic for maintaining synchronization of
the messages and other information between the wireless device and
the messaging service.
Inventors: |
Friend; John; (Los Altos,
CA) ; Belshe; Michael; (Sunnyvale, CA) ;
Collins; Roger; (Novato, CA) ; Bennett; Mike;
(Brisbane, CA) |
Correspondence
Address: |
BLAKELY SOKOLOFF TAYLOR & ZAFMAN
1279 OAKMEAD PARKWAY
SUNNYVALE
CA
94085-4040
US
|
Family ID: |
30002541 |
Appl. No.: |
11/807290 |
Filed: |
May 24, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10109928 |
Mar 29, 2002 |
7243163 |
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11807290 |
May 24, 2007 |
|
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09924283 |
Aug 7, 2001 |
7155483 |
|
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10109928 |
Mar 29, 2002 |
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Current U.S.
Class: |
709/248 ;
707/E17.032 |
Current CPC
Class: |
H04L 67/14 20130101;
H04L 67/1095 20130101; H04W 76/10 20180201; H04L 51/38 20130101;
G06F 15/16 20130101; H04L 12/1895 20130101; H04W 76/12 20180201;
H04L 12/56 20130101; G06F 16/27 20190101; H04W 4/12 20130101; H04L
69/329 20130101; H04L 29/08 20130101; H04L 67/325 20130101; H04L
69/04 20130101; H04L 67/04 20130101; H04L 29/06 20130101; H04W 8/26
20130101; H04L 45/24 20130101 |
Class at
Publication: |
709/248 |
International
Class: |
G06F 15/16 20060101
G06F015/16 |
Claims
1-41. (canceled)
42. A system comprising: a wireless data processing device; a
messaging service to maintain data objects on behalf of a user; and
synchronization means for maintaining synchronization of said data
objects between said wireless device and said messaging service
over a wireless network, said synchronization means transmitting
data object transaction updates originating at said service to said
wireless device as modifications occur to data objects at the
service and wirelessly transmitting data object transaction updates
originating at said wireless device to said service as
modifications occur to data objects at the wireless device.
43. The system as in claim 42 wherein said data objects include
e-mail messages.
44. The system as in claim 43 wherein said data objects include
electronic calendar data.
45. The system as in claim 44 wherein said data objects includes a
to-do list data.
46. The system as in claim 45 wherein said data objects include
contact information.
47. The system as in claim 42 wherein said synchronization means
further comprises compression means for compressing said messages
and other information transmitted between said wireless device and
said service.
48. The system as in claim 42 wherein said synchronization means
further comprises batch-processing means for combining groups of
data object transaction updates before transmitting said updates
between said wireless data processing device and said messaging
service.
49. The system as in claim 42 wherein said data processing device
comprises control means allowing said user to modify configuration
parameters of said messaging service from said data processing
device.
50. The system as in claim 42 wherein said synchronization means
synchronizes message transaction updates including the movement of
messages between e-mail folders.
51. The system as in claim 50 wherein one of said message
transaction updates comprises indications that said user has viewed
a message from said wireless data processing device.
52. The system as in claim 42 wherein said synchronization means
further comprises: a first batch processing means configured at a
customer site at which said service operates; and a second batch
processing means configured at a data center communicatively
coupled between said wireless data processing device and said
customer site.
53. The system as in claim 52 wherein said first batch processing
means combines data object transactions concurrently executed by a
user at said customer site before transmitting said data object
transactions and wherein said second batch processing means
combines data object transactions not concurrently executed by said
user.
54. A system for synchronizing a wireless device with a service
comprising: an interface communicatively coupled between said
service and said wireless device, said interface executed at a
customer site at which said service in installed and configured to
transmit data object transaction updates to said wireless device as
modifications occur to data objects at the service, and to transmit
data object transaction updates to said service as modifications
occur to data objects at the wireless device; and a data center
communicatively coupled between said wireless device and said
interface, said data center temporarily storing said data object
transaction updates until said data object transaction updates are
successfully transmitted to said wireless device.
55. The system as in claim 54 further comprising: batch processing
logic to group said data object transaction updates together prior
to transmission to said wireless device and/or to said
interface.
56. The system as in claim 55 wherein said batch processing logic
further comprises: a first level of batch processing logic
implemented at said interface, said first level of batch processing
logic grouping data object transaction updates concurrently
executed by a user prior to transmitting said data object
transaction updates; and a second level of batch processing logic
implemented at said data center, said second level of batch
processing logic grouping data object transaction updates
individually executed by said user prior to transmitting said data
object transaction updates to said wireless device.
57. The system as in claim 54 wherein said interface combines two
or more data object transactions at said service into an equivalent
single data object transaction to be transmitted to said wireless
device.
58. The system as in claim 57 wherein said two or more data object
transactions comprise a delete command deleting a data object from
a source location on said service and a new command reproducing
said data object in a destination location, and wherein said single
data object transaction transmitted to said wireless device is a
move command.
59. A wireless data processing device comprising synchronization
logic for maintaining synchronization of said data objects with a
messaging service via a wireless network by transmitting data
object transaction updates to said service as modifications occur
to data objects at the wireless device.
60. The wireless data processing device as in claim 59 wherein
further comprising compression logic for compressing said messages
and other information transmitted to said service.
61. wireless data processing device as in claim 42 further
comprising batch-processing logic for combining groups of data
object transaction updates before transmitting said updates to said
messaging service.
Description
PRIORITY
[0001] This application is a continuation-in-part of co-pending
U.S. Application entitled APPARATUS AND METHOD FOR CONSERVING
BANDWIDTH BY BATCH PROCESSING DATA TRANSACTIONS, Ser. No.
09/924,283, filed Aug. 7, 2001.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention relates generally to the field of network
data services. More particularly, the invention relates to an
apparatus and method for synchronizing a wireless data processing
device with a wireless messaging service.
[0004] 2. Description of the Related Art
[0005] A variety of wireless data processing devices have been
introduced over the past several years. These include wireless
personal digital assistants ("PDAs") such as the Palm.RTM. VIx
handheld, cellular phones equipped with data processing
capabilities (e.g., those which include wireless application
protocol ("WAP") support), and, more recently, wireless messaging
devices such as the Blackberry.TM. wireless pager developed by
Research In Motion ("RIM")..TM.
[0006] Personal digital assistants such as the Palm devices
typically provide only limited wireless messaging capabilities
(e.g., instant messaging and basic Internet access). For example,
these devices typically require a user to manually establish a
connection to the Internet via an Internet Service Provider ("ISP")
or to a corporate server to check e-mail messages.
[0007] Although corporate messaging systems such as the RIM
Blackberry provide more comprehensive messaging capabilities, there
are significant limitations to these systems. Specifically, these
systems employ e-mail "redirection" or "forwarding" techniques in
which messages are redirected to the wireless device only if
certain conditions are met. These conditions, referred to as
"redirection events," may include, for example, an indication that
the user is not working at his corporate desktop (e.g., removal of
the wireless device from the desktop cradle, a screen saver firing
on the desktop, . . . etc) or a manual redirection command
initiated by the user (e.g., via the wireless device or the
corporate desktop). One such message redirection system is
described in U.S. Pat. No. 6,219,694 ("System and Method for
Pushing Information From a Host System to a Mobile Data
Communication Device Having a Shared Electronic Address").
[0008] As a result, these systems are (as a practical matter)
incapable of providing complete synchronization between the
wireless device and the corporate e-mail database. For example,
because messages are only redirected to the wireless device under
certain conditions (e.g., following a redirection event), at any
given point in time, the wireless device may contain an incomplete
set of e-mail data. Moreover, even when messages are actively being
forwarded to. the wireless device, the e-mail data stored at the
wireless device and the e-mail database are not truly synchronized.
For example, certain types of transactions performed on the
wireless device, such as an indication that a message has been
viewed by the user, message deletions, movement of messages from
one folder to another, . . . etc., are not updated at the e-mail
service wirelessly.
[0009] Moreover, only basic e-mail functions such as sending and
receiving messages may be controlled at the wireless device. More
advanced e-mail management functions must be set at the user's
desktop (e.g., configuring e-mail filters, outgoing e-mail
signatures, security settings such as passwords, . . . etc).
[0010] In addition, prior messaging systems require a corporate
desktop to which the device must be attached when the user is in
the office. The problem with this is not merely that a corporate
desktop is required, but also that the corporate desktop must be
configured with software and a proprietary "cradle" that allows it
to communicate directly to the wireless device.
[0011] Accordingly, what is needed is a system and method for
providing complete synchronization and management between a
wireless device and a messaging service (e.g., a corporate e-mail
account). What is also needed is a wireless apparatus for receiving
and sending e-mail messages which does not require a corporate
desktop or any software to be installed and executed on the
corporate desktop.
SUMMARY
[0012] A system is disclosed in which a data processing device is
completely synchronized with a messaging service. One embodiment of
the system comprises a wireless data processing device; a messaging
service to maintain messages and other information on behalf of a
user; and synchronization logic for maintaining synchronization of
the messages and other information between the wireless device and
the messaging service.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] A better understanding of the present invention can be
obtained from the following detailed description in conjunction
with the following drawings, in which:
[0014] FIG. 1 illustrates an exemplary network architecture used to
implement elements of the present invention.
[0015] FIG. 2 illustrates one embodiment of a system for
compressing data.
[0016] FIGS. 3a-c illustrate an exemplary sequence of related
e-mail messages.
[0017] FIG. 4 illustrates one embodiment of a method for
compressing data using redundant data found in previous
messages.
[0018] FIG. 5 illustrates one embodiment of an apparatus for
performing state-based compression.
[0019] FIG. 6 illustrates one embodiment of a state-based data
compression format.
[0020] FIG. 7 illustrates a code word table employed to compress
data according to one embodiment of the invention.
[0021] FIG. 8 illustrates one embodiment of a method for
compressing data with code words.
[0022] FIG. 9 illustrates a text compression module coordinating
data compression tasks between a plurality of other compression
modules.
[0023] FIG. 10 illustrates a compressed data format according to
one embodiment of the invention.
[0024] FIG. 11 illustrates one embodiment of a system for
synchronizing message transactions between a wireless device and a
service.
[0025] FIG. 12 illustrates an improved embodiment of a system for
synchronizing message transactions between a wireless device and a
service.
[0026] FIG. 13 illustrates a method for determining whether to
enter a batch processing mode.
[0027] FIG. 14 illustrates an embodiment of the invention which
employs multi-level batch processing.
[0028] FIG. 15 illustrates an embodiment of the invention which
employs in-order control functions.
[0029] FIG. 16 illustrates an embodiment of the invention which
maps synchronization identification codes to standard
identification codes.
[0030] FIG. 17 illustrates an embodiment of the invention for
detecting and resolving data object version conflicts.
[0031] FIG. 18 illustrates an embodiment of the invention in which
a move command is transmitted to a wireless device in lieu of a
delete command and a new command.
[0032] FIGS. 19a and b illustrate embodiments of a method for
generating a move command.
DETAILED DESCRIPTION
[0033] In the following description, for the purposes of
explanation, numerous specific details are set forth in order to
provide a thorough understanding of the present invention. It will
be apparent, however, to one skilled in the art that the present
invention may be practiced without some of these specific details.
In other instances, well-known structures and devices are shown in
block diagram form to avoid obscuring the underlying principles of
the present invention.
An Exemplary Network Architecture
[0034] FIG. 1 illustrates one embodiment of a network architecture
for implementing the compression techniques described herein. The
"customer site" 120 illustrated in FIG. 1 may be any local-area or
wide-area network over which a plurality of servers 103 and clients
110 communicate. For example the customer site may include all
servers and clients maintained by a single corporation. The servers
103 may be configured to provide a variety of different messaging
and groupware services 102 to network users (e.g., e-mail, instant
messaging, calendaring, . . . etc). In one embodiment, these
services are provided by Microsoft Exchange. However, the
underlying principles of the invention are not limited to any
particular messaging/ groupware platform.
[0035] In one embodiment of the invention, an interface 100
forwards data objects maintained by the service 102 (e.g., e-mail
messages, instant messages, calendar data, . . . etc) to a
plurality of wireless data processing devices (represented in FIG.
1 by wireless device 130) via an external data network 170 and/or a
wireless service provider network 171. For example, if the service
102 includes an e-mail database, the interface 100 transmits any
new e-mails which arrive in a user's mailbox on the service 102 to
the user's wireless data processing device 130 (over the network(s)
170 and/or 171). Alternatively, or in addition, the service 102 may
provide the e-mail to the user's local computer (e.g., client 110)
upon request (i.e., so that the user will receive the e-mail on
his/her wireless device 130 when out of the office and on his/her
personal computer 110 when in the office). Conversely, e-mail
messages sent from the user's wireless data processing device 130
are transmitted to the service 102 via the interface 100.
[0036] In one embodiment, the interface 100 is a software module
adapted to work with the particular service 120. It should be
noted, however, that the interface 100 may be implemented in
hardware or any combination of hardware and software while still
complying with the underlying principles of the invention.
[0037] In one embodiment, the external data network 170 is
comprised of a plurality of servers/clients (not shown) and other
networking hardware (e.g., routers, hubs, . . . etc) for
transmitting data between the interface 100 and the wireless
devices 130. In one embodiment, the interface 100 encapsulates data
in one or more packets containing an address identifying the
wireless devices 130 (e.g., such as a 24-bit Mobitex Access Number
("MAN #")). The external data network 170 transmits the packets to
a wireless service provider network 171 which, in turn, transmits
the packets (or the data contained therein) over a wireless
communication link to the wireless device 130. In one embodiment,
the wireless service provider network is a 2-way paging network.
However, various other network types may be employed (e.g., CDMA
2000, PCS, . . . etc) while still complying with the underlying
principles of the invention.
[0038] It should be noted that the network service provider network
171 and the external data network 170 (and associated interface
100) may be owned/operated by the same organization or,
alternatively, the owner/operator of the external data network 170
may lease wireless services from the wireless service provider
network. The underlying principles of the invention are not limited
to any particular service arrangement.
[0039] In one embodiment of the invention, the service 102 (e.g.,
the e-mail database) is fully synchronized with the wireless data
processing device 130. Thus, any actions performed on the wireless
device 130 are automatically updated on the service 102 and any
transactions occurring at the service 102 are automatically
reflected on the device 130. Synchronization updates of this type
may include but are not limited to device configuration
modifications, calendar updates, e-mail message updates, instant
messages, to-do list updates and/or any other type of personal
information management transactions or corporate data management
transactions (hereinafter "message transactions"). As one example,
when a user views an e-mail message using the device 130, an
indication that the user viewed the message is transmitted to the
service 102 (via the interface 100). Accordingly, if the user
subsequently connects to e-mail via a client 110, the e-mail will
appear as having already been viewed. Other actions such as message
deletions, filing activities (e.g., moving a message to a
particular folder), message responses, meeting
confirmations/additions . . . etc, will automatically be reflected
in the service 102, thereby providing complete synchronization
between the service 102, the device 130 and/or the client 110 (if
one is being used).
[0040] Current messaging systems do not offer complete wireless
device synchronization. As such, these systems require that the
user have a desktop computer with a "cradle" to which the device is
attached to received certain types of synchronization updates. One
reason for this is that prior systems process message transactions
in a relatively inefficient manner and employ only limited
compression techniques, thereby making complete synchronization
impractical. As such, in order to realize complete wireless
synchronization, embodiments of the invention employ one or more of
the following compression and/or message processing techniques.
State-Based Compression
[0041] FIG. 2 illustrates certain aspects of the wireless data
processing device 130 and the interface 100 in greater detail. In
one embodiment, the data processing device 130 is comprised of a
local data compression/decompression module 225 (hereinafter "codec
module 225") and a local message cache 210. The local codec module
225 compresses outgoing data and decompresses incoming data using
the various compression techniques described herein.
[0042] The local message cache 210 is comprised of an input queue
211 for temporarily storing a incoming messages and an output queue
212 for storing outgoing messages. Although illustrated as separate
logical units in FIG. 2, the local message cache 210 may be
comprised of only a single block of memory for storing both
incoming and outgoing messages according to a cache replacement
policy. In one embodiment, messages are maintained in the input
queue and/or output queue using a first-in, first-out ("FIFO")
replacement policy. However, various other cache replacement
techniques may be employed while still complying with the
underlying principles of the invention. For example, a
least-recently used ("LRU") policy may be implemented where
messages used least frequently by the local codec module 225 are
stored in the cache for a shorter period of time than those used
more frequently. As described below, messages used more frequently
by the local codec module 225 may frequently include messages which
form part of a common e-mail thread, whereas those used less
frequently may include junk mail or "spam" (i.e., for which there
is only a single, one way message transmission).
[0043] The interface 100 of one embodiment is comprised of a remote
data compression/decompression module 220 (hereinafter "codec
module 220") and a remote message cache 200 with a remote input
queue 201 and a remote output queue 202. The codec module 220
compresses messages transmitted to the wireless data processing
device 130 and decompresses messages received from the data
processing device 130 according to the techniques described herein.
The remote message cache 200 temporarily stores messages
transmitted to/from the data processing device 130 (e.g., using
various cache replacement algorithms as described above). In one
embodiment, the cache replacement policy implemented on the
interface 100 is the same as the policy implemented on the wireless
device 130 (i.e., so that cache content is synchronized between the
remote cache 200 and the local cache 210).
[0044] FIGS. 3a-c illustrate an exemplary sequence of e-mail
messages which will be used to describe various aspects of the
invention. FIG. 3a illustrates the initial e-mail message 300 in
the sequence which (like most e-mail messages) is logically
separated into a header information portion 305 and a text
information portion 310. Also shown in FIG. 3a is an attachment
320, indicating that a document is attached to the message and an
electronic signature which may be automatically inserted in the
message by the sender's (i.e., John Smith's) e-mail client.
[0045] FIG. 3b illustrates the second e-mail message 301 in the
sequence transmitted by user Roger Collins in response to the
initial e-mail message. As indicated by the new header information
335, this message is transmitted directly to the initial sender,
John Smith, and to a user who was CC'ed on the initial e-mail
message, Tom Webster. The message is also CC'ed to everyone else in
the group to whom the initial message was transmitted. This "reply
to all" feature, which is found in most e-mail clients, provides a
simple mechanism for allowing a sequence of e-mail messages to be
viewed by a common group of individuals.
[0046] As illustrated in FIG. 3b, the text 310 of the initial
e-mail message 300 is substantially reproduced in the new e-mail
message. This "reply with history" feature is also common to most
e-mail clients, allowing a sequence of comments from the
individuals in the common group to be tracked from one e-mail
message to the next. Also illustrated are a plurality of characters
316 inserted by the responder's (Roger Collins') e-mail system at
the beginning of each line of the original e-mail text. This
feature, which is common in some (but not all) e-mail systems,
allows users to differentiate between new text and old text.
[0047] Accordingly, even after the initial e-mail response in a
sequence of e-mails, the e-mail history (i.e., the portions of text
and attachments reproduced from prior messages) represents a
significant portion of the overall message, resulting in the
transmission of a significant amount of redundant information being
transmitted over the wireless network, in both the text portion of
the e-mail and the header portion of the e-mail.
[0048] FIG. 3c illustrates the final e-mail message 302 in the
sequence in which the addressee of the second e-mail responds to
the sender of the second e-mail and CC's all of the other members
in the group. As illustrated, the only non-redundant information in
the e-mail message 302 is a few lines of text 355. The e-mail
addresses of all of the group members are the same as in the
previous two messages (although switched between different fields,
the underlying addresses are the same) and the text and header
information from the previous messages 300, 301, including the
attachment 320 are reproduced, with only a few minor modifications
(e.g., the additional ">"characters inserted by the e-mail
system).
[0049] One embodiment of the invention compresses e-mail messages
by taking advantage of this high level of redundancy. In
particular, rather than sending the actual content contained in new
e-mail messages, portions of the new messages identified in
previous e-mail messages stored in the caches 200, 201 are replaced
by pointers to the redundant portions. For example, in message 302
all of the redundant content from message 301 may be replaced by a
pointer which identifies the redundant content in message 301
stored in the cache of the user's wireless device. These and other
compression techniques will be described in greater detail
below.
[0050] FIG. 4 illustrates one embodiment of a method for
compressing messages using redundant content found in previous
messages. This embodiment will be described with respect to FIG. 5,
which illustrates certain aspects of the message interface 100 in
greater detail. At 400, the interface 100 receives a message (or a
group of messages) to be transmitted to a particular wireless data
processing device 130. At 405, the message is analyzed to determine
whether it contains redundant data found in previous messages. In
one embodiment, this is accomplished via message identification
logic 500 shown in FIG. 5 which scans through previous e-mail
messages to locate those messages containing the redundant
data.
[0051] Various message identification parameters 505 may be used by
the message identification logic 500 to search for messages. For
example, in one embodiment, the message identification logic will
initially attempt to determine whether the new message is the
latest in a sequence of messages. Various techniques may be
employed by the message identification logic 500 to make this
determination. For example, in one embodiment, the message
identification logic 500 will search the subject field of the
message for the stings which indicate the new message is a response
to a prior message. If these strings are identified, the message
identification logic 500 may then look for the most recent message
in the sequence (e.g., based on the text found in the subject
field). For example, referring back to the FIGS. 3a-c, upon
receiving message 302, the message identification logic 500 may
identify the message 302 as part of a sequence based on the fact
that it contains "RE: Patent Issues" in the subject field. The
identification logic 500 may ignore the RE: (or FW: if the message
is forwarded) and scan to the text in another message which matches
the remainder of the subject field (i.e., "Patent Issues") and
identify the most recent previous message containing that text in
it's subject header.
[0052] If the message subject does not contain characters such as
RE: or FW: indicating that the message is part of a sequence, then
message identification logic 500 may employ a different set of
identification parameters 505 for identifying previous messages.
For example, in one embodiment, the message identification logic
500 will search for the most recent message in which the sender of
the new message is listed in the header (e.g., as the recipient).
Moreover, the message identification logic 500 may search for
certain keywords or combinations of words indicating that the
message contains relevant data (e.g., such as the electronic
signature 315 illustrated in FIGS. 3a-c). In one embodiment, the
message identification logic 500 may generate a prioritized subset
of messages which (based on the defined parameters 505) are the
candidates most likely to contain content found in the new
message.
[0053] If no redundant data exists in prior messages, determined at
410, then at 420 additional compression techniques are applied to
compress the message, some of which are described below. If,
however, redundant data exists in prior messages then, at 415, the
redundant data is replaced with pointers/offsets identifying the
redundant data on the cache 210 of the wireless device 130 (or in
the cache 200 of the interface 100, depending on the direction of
message transmission). As illustrated in FIG. 5, in one embodiment,
this is. accomplished by state based compression logic 510 which
generates the pointers/offsets using the messages identified by the
message identification logic 500.
[0054] FIG. 6 illustrates one embodiment of a state-based
compression format generated by the state-based compression logic
510. As illustrated, the format is comprised of a one or more
chunks of non-redundant data 601, 610, 620 separated by offsets
602, 612, lengths 603, 613, and message identification data 604,
614, which identify blocks of data from previous messages. For
example, if the compression format of FIG. 6 were used to encode
message 302 shown in FIG. 3c, the new text 302 might be stored as
non-redundant data 601, whereas all of message 301 might be
identified by a particular message ID 604, followed by an offset
602 identifying where to begin copying content from message 301 and
a length 603 indicating how much content to read from the address
point identified by the offset.
[0055] Similarly, if message 301 from FIG. 3b were encoded by the
state-based compression logic 510, the new text portion 340 might
be stored as non-redundant data 601. Moreover, each of the ">"
characters automatically inserted by the e-mail system 316 might be
transmitted as non-redundant data, separated by lines of redundant
data identified by offsets and lengths (i.e., at the end of each
redundant line in message 300 identified by lengths/offsets in the
new message, a new, non-redundant ">" would be inserted).
[0056] In one embodiment, when a user has not received messages for
a long period of time, numerous related messages (e.g., such as
messages 300-302) may build up in his inbox on the e-mail service
102. Accordingly, in one embodiment, the interface 100 will employ
state-based compression techniques as described above using
pointers to messages which have not yet arrived in the cache of the
user's wireless device. That is, the interface 100 will determine
where messages in the group (stored in the user's inbox on the
service 102) will be stored in the cache 210 of the wireless data
processing device 130 once the user re-connects to the service.
[0057] Referring once again to FIGS. 4 and 5, once the state-based
compression logic 510 finishes compressing the message, the
compressed message 515 may be transmitted to the user's wireless
device 130. Alternatively, at 420, additional compression
techniques (described below) may be applied to compress the message
further. Once the message is fully compressed it is transmitted to
the wireless device (at 425) where it may be decompressed via codec
module 225.
[0058] The state-based compression techniques were described above
in the context of an interface 100 compressing messages before
transmitting the messages to a wireless device 130. It will be
appreciated, however, that the same compression techniques may be
performed by the wireless device 130 before it transmits a message
to the interface 100 (e.g., lengths/offsets may identify redundant
data stored in the remote message cache 200). In addition, although
described above with respect to e-mail messages, the described
compression techniques may be employed to compression various other
message types (e.g., newsgroup articles, instant messages, HTML
documents . . . etc).
Supplemental/Alternative Compression
[0059] Various additional compression techniques may be employed,
either in addition to or as an alternative to the state-based
compression techniques just described.
[0060] In one embodiment of the invention, common characters and
strings of characters (i.e., which are frequently transmitted
between the wireless device 130 and the interface 100) are encoded
using relatively small code words whereas infrequent characters or
strings of characters are encoded using relatively larger code
words. In order to encode data in this manner, a statistical
analysis is performed to identify common character strings. Based
on the statistical analysis, a lookup table similar to the one
illustrated in FIG. 7 is generated and maintained at both the
wireless device 130 and the interface 100. As illustrated, certain
character strings such as the domain used for corporate e-mail
"@good.com" and the first 6 digits of the corporate telephone
number, e.g., "(408)720-" may be quite common. As such, replacing
these common bit strings with relatively small code words may
result in a significant amount of compression. Referring back to
messages 300-302, using this compression technique, the domain
"@good.com" encountered numerous times in each message header could
be replaced by a short, several-bit code word.
[0061] In one embodiment, a different look up table may be
generated for different types of data transmitted between the
interface 100 and the wireless data processing device 130,
resulting in greater precision when identifying common strings of
characters. For example, a different set of code words may be used
to compress e-mail messages than that used to compress the
corporate address book. Accordingly, the code word table used to
compress e-mail messages would likely contain relatively small code
words for the most common e-mail domains whereas the corporate
address book might also contain relatively small code words for the
corporate address and portions of the corporate phone number.
[0062] Moreover, in one embodiment, a unique code word table may be
generated for each field within a particular type of data. For
example, a different code word table may be employed for the e-mail
header field than that used for the remainder of the e-mail
message. Similarly, a different table may be generated for the
"address" field of the corporate address book than that used for
the "e-mail address" field, resulting in even greater precision
when generating the set of code words.
[0063] Rather than statistically generating and transmitting a code
word table for each field, alternatively, or in addition, one
embodiment of the invention refers to a dictionary of "known"
words, like an English dictionary, and therefore does not need to
transmit the dictionary with the data. For example, in one
embodiment, a spell-check dictionary maintained on the wireless
device 130 and/or the interface 100 may be used to compress
content. Rather than sending the actual text of the e-mail message,
each word in the message would be identified by its entry in the
spell-check dictionary (e.g., the word "meeting" might be replaced
by entry#3944).
[0064] One type of data particularly suitable to the foregoing
types of compression is the corporate address book maintained on
most corporate e-mail servers. In one embodiment of the invention,
the corporate address book is synchronized initially through a
direct link to the client 110 (see FIG. 1). On the initial
synchronization (e.g., when the wireless device is directly linked
to the client 110), statistics on common letters and "tokens"
(e.g., names, area codes, e-mail domains) are generated. The
statistics and tokens are then used to compress the data as
described above. Thereafter, any changes to the address book are
wirelessly transmitted. On subsequent updates, the compressors on
both sides (wireless device 130 and interface 100) would refer to
the earlier statistics gathered, and thus compress without any new
statistics or words being transmitted.
[0065] The updates may represent a small percentage of the entire
address book, but may still represent a significant number of
bytes, especially when multiplied by all the wireless devices in
use in use at a given company. Accordingly, reducing the amount of
data required to transmit the updates to the address book as
described above, would result in a significant savings in
transmission costs. Additionally, as the address book can be very
large relative to the storage available on the client, storing the
address book on the client in a compressed form will allow more
entries to be stored.
[0066] In one embodiment, to conserve additional space, only
certain fields of the corporate address book will be synchronized
wirelessly. For example, only the Name, Address, E-mail, and Phone
Number fields may be updated wirelessly. All fields of the address
book may then be updated when the wireless device is once again
directly linked to the client 110.
[0067] One embodiment of a method for generating a code word table
is illustrated in FIG. 8. At 810, occurrences of certain byte
strings are calculated for use by a standard Huffman compression
algorithm. At 820 certain "tokens" are generated for a particular
field based on the natural boundaries for that field type. For
example, as described above, e-mail addresses could be broken into
".com" and "@good.com" as described above for e-mail fields. Phone
numbers might be broken into "(650)" and "(650)620-" for address
book fields.
[0068] At 830 the occurrences of tokens are counted in the same way
as the occurrences of the byte strings are counted, though one
occurrence of, say, a four-byte token adds four to the count. At
840 a code word table of all the letters and those tokens that
occur more than once (or maybe the top N tokens that occur more
than once) is generated. Part of the table will include the tokens
themselves. At 850, each record is compressed using the code word
table of characters and tokens and, at 860, the code word tables
and the compressed records are then sent to the wireless device
130.
[0069] In one embodiment, the code word tables are identified with
a unique number, such as a timestamp. Both the interface 100 and
the wireless device 130 would store the tables. On the wireless
device 130, the records may remain compressed to conserve space,
being decompressed only when opened. On subsequent syncs, the
wireless device 130 may request updates to the corporate
dictionary. As part of the request, the wireless device 130 may
include the unique number assigned to the code word tables. If, for
some reason, the wireless device 130 doesn't have the original
tables, it may send a particular type of ID to notify the interface
100 (e.g., by using a "0" for the ID). Likewise, if the host
doesn't recognize the ID for some reason, it can ignore the
original tables and create new ones.
[0070] In most cases, however, the wireless device 130 and
interface 100 will agree on what the ID is, and the compression of
the update will use the existing code word tables previously
computed. For example, a new employee with the same e-mail domain
and phone prefix as existing employees would compress nicely. Since
the updates should be a small percentage of the overall address
book, it will most likely be very similar to the existing data.
[0071] One embodiment of the invention converts alphanumeric
characters (e.g., standard ASCII text) into a proprietary
variable-bit character format, allocating relatively fewer bits for
common characters and relatively more bits for uncommon characters.
In one particular embodiment, 6 bits are allocated for most
characters, and 12 bits are allocated for all other characters.
This embodiment may be seamlessly integrated with the other forms
of compression described above (e.g., message pointer generation,
code word lookups, . . . etc) through an escape function described
below.
[0072] Most messages will have ASCII text in them. For example, the
TO: field in an e-mail, or the name in an Address Book entry are
generally comprised of ASCII text. Most ASCII text use 7
bits/character. Typical exceptions are accented characters, like n
or o. Realistically, though, most text in a text field consists of
a-z, 0-9, space, and a few symbols.
[0073] Compressing text using code word tables as described above
is a good way to encode large amounts of text, because it gathers
statistics about how frequently a given character occurs, and
represents more frequent characters in fewer bits. For example, the
letter `e` occurs more often than the letter `k`, so it may be
represented in, say, 3 bits. It is also particularly suitable for
compressing data in specific data fields where it is known that the
same character strings appear regularly (e.g., such as the e-mail
domain "@good.com"). One problem with this technique, however, is
that it requires transmitting and storing the statistical
information with the encoded text. For small amounts of text (e.g.,
short e-mail messages), this becomes impractical.
[0074] A 6-bit character format provides for 64 characters
(2.sup.6=64). In one embodiment, the following symbols are encoded
using 6-bits: a zero, handy for denoting the end of strings; `a`
through `z;` `0` through `9;` space; and the most common symbols
(e.g., dot, comma, tabs, new-lines, @, parens, !, colon, semicolon,
single, double quotes, . . . etc). The values above account for 48
of the 64 values, leaving 16 values remaining.
[0075] In one embodiment, the remaining 16 values are used for the
following escape values:
[0076] (1) Four values for combining with the next 6-bits to allow
any possible ASCII value to be encoded in two 6-bit values. It
allows for any upper case letter, symbols not in the top ten,
accented characters, and so on. For example, binary values of 60,
61, 62, and 63 may each identify another 6-bit value which contains
the underlying character information. This provides for the coding
of an additional 256 characters (4*64=256), more than enough to
encode the entire US-ASCII character set.
[0077] (2) Shift Lock. Turns on shifting until a subsequent Shift
Lock turns off shifting. For letters, this is like a caps lock. For
numbers and symbols, this may have no effect. Alternatively, a
second set of values may be defined when shift lock is on (e.g., a
second "top ten" list of symbols).
[0078] In one embodiment, the remaining 11 6-bit characters are
"installable escape values," allowing one or more standard or
custom compressors. For example, the TO:, FROM:, CC:, and BCC:
fields in an e-mail all contain a list of e-mail addresses,
separated by a semicolon. As such, the following special escape
values may be defined: (1) the customer's/user's e-mail address may
be converted into a 6-bit value; (2) the customer's/user's domain
may be converted into a 6-bit value (e.g., "@Good.Com" would become
6 bits); (3) "common" domain names and suffixes may be converted
into a 6-bit value and a 6-bit argument (e.g., the "common" list
may be 64 of the most common names, and might include "@aol.com",
"@webtv.com", ".com", ".net",".org", ".gov", ".us", ".uk", . . .
etc); and (4) names "used recently" in an e-mail may be converted
into a 6-bit value and a 6-bit argument. Elsewhere in the message
is the e-mail ID this is dependent on. The argument might include 2
bits identifying the field (TO:, FROM:, CC:, or BCC:), and 4 bits
identifying the first 16 e-mail addresses in that field.
[0079] The new character format may be employed seamlessly with the
other types of compression described above (e.g., code words,
repeated characters; LZ compression; dictionary lookups; and/or
referring to prior messages). In one embodiment, illustrated in
FIG. 9, a text compression module 900 compresses text according to
the 6-bit character format described above and coordinates
compression functions between various other compression modules. In
the illustrated embodiment, this includes a state-based compression
module 910 for compressing messages by referring to prior, cached
messages (as described above) and a code word compression module
920 which compresses common character strings using code words
(e.g., by encoding statistically-analyzed tokens, referring to a
spell-check dictionary, . . . etc, as described above). In
addition, as indicated by alternative compression module 930,
various other types of compression may be employed on the system to
attain an even greater level of compression (e.g., standard LZ
compression).
[0080] FIG. 10 illustrates an exemplary portion of e-mail message
302 (from FIG. 3c) encoded according to this embodiment of the
invention. Starting from the upper right corner of the e-mail
message 302, the text compression module 900 begins encoding the
first set of characters (i.e., starting with the addressee field
"TO:"). With each character it coordinates with the other
compression modules 910, 920, 930 to determine whether those
modules can achieve greater compression. If not, then the text
compression module 900 encodes the text according to the 6-bit
character format. If a higher level of compression can be achieved
with one of the other compression modules 910, 920, 930, however,
the text compression module 900 hands off the compression task to
that module and inserts an "escape" sequence of bits indicating
where the compression task was accomplished by that module.
[0081] For example, as illustrated in FIG. 10, the escape sequence
"110010" following the first three characters ("TO:") indicates
that the code word generation module 920 compresses the subsequent
portion of data. In operation, once this point in the e-mail
message is reached, the code word generation module 920 notifies
the text compression module 900 that it can achieve a higher level
of compression using code words (e.g., using a tokenized e-mail
address). Accordingly, the sequence "1011001000" following the
escape sequence "110010" is a code word representing the tokenized
e-mail address "Collins, Roger" <rcollins@good.com>.
Alternatively, two or more code words may be used to encode the
e-mail address, depending on the particular set of code words
employed by the system (e.g., one for the individual's name and a
separate one for the domain "@good.com"). As indicated in FIG. 10,
the text compression module 900 may then pick up the encoding
process following the tokenized e-mail address (i.e., the return
character followed by the text "FROM:").
[0082] After the e-mail header information is encoded, the block of
new text 355 is encoded using the 6-bit character format. Of
course, depending on the code words employed by the code word
generation module 920 and/or previous e-mails on the system,
portions of the block of new text 355 may also be encoded using
code words and/or pointers to previous messages. Following the text
block 355, the state-based compression module 910, after analyzing
the message, notifies the text compression module 900 that it can
achieve a higher level of compression by identifying content found
in a previous message. As such, an escape sequence "110011" is
generated indicating that compression is being handled by the
state-based compression module 910 from that point onward. The
state-based compression logic 910 then identifies a previous e-mail
message using a message ID code (indicating message 301), and
generating an offset and a length indicating specific content
within that e-mail message (e.g., employing one or more of the
state-based compression techniques described above).
[0083] It should be noted that the specific example shown in FIG.
10 is for the purpose of illustration only. Depending on the code
words employed by the system and/or the previous messages stored on
the system, the actual encoding of the e-mail message 302 may turn
out to be different than that illustrated. For example, as
mentioned above, the block of text 355 may be encoded using code
words and/or pointers to previous messages as well as the 6-bit
character format.
[0084] Various supplemental/alternative compression techniques may
also be employed (e.g., represented by alternate compression module
930). In one embodiment, certain types of data are not transmitted
wirelessly between the wireless data processing device 130 and the
interface 100. For example, in one embodiment, when a device has
been unable to receive messages for a certain period of time (e.g.,
one week), only message headers are initially transmitted to the
device 130, thereby avoiding an unreasonably long download period
(i.e., wherein all messages received over the period of
unavailability are transmitted to the device). Alternatively, or in
addition, in one embodiment, when the device is out of touch for an
extended period of time, only relatively new messages (e.g.,
received over a 24-hour period) are transmitted to the device when
it comes back online. Similarly, in one embodiment, only e-mail
header information is transmitted to the wireless device 130 (e.g.,
indicating the subject and the sender) when the user is a CC
addressee and/or when the e-mail is from a folder other than the
user's inbox.
[0085] In one embodiment, only certain fields are updated on the
device 130. For example, with respect to a corporate or personal
address book, only Name, E-mail Address and Phone Number fields may
be synchronized on the device 130. When the device is connected
directly to the client, all of the fields may then be updated.
[0086] In one embodiment, certain details are stripped from e-mail
messages to make them more compact before transmitting them to the
device 130. For example, only certain specified header information
maybe transmitted (e.g., To, From, CC, Date, Subject, body, . . .
etc). Similarly, the subject line may be truncated above a certain
size (e.g., after 20 characters). Moreover, attachments and various
formatting objects (e.g., embedded pictures) may not be
transmitted. In one embodiment, when a user lists him/herself as a
CC addressee on an outgoing message, this message will not be
retransmitted back to the wireless device 130.
[0087] Although attachments may not be transmitted to the wireless
device 130, in one embodiment, users may still forward the
attachments to others from the wireless device (the attachments
will, of course, be stored on the e-mail server). Moreover, in one
embodiment, attachments may be sent to a fax machine in response to
a user command from the wireless device 130. Accordingly, if a user
is away from the office and needs to review a particular
attachment, he can type in the number of a nearby fax machine and
transmit this information to the interface 100. The interface 100
will then open the attachment using a viewer for the attachment
file type (e.g., Word, Power Point, . . . etc) and transmit the
document via a fax modem using the fax number entered by the user.
Thus, the user may view the attachment without ever receiving it at
the device.
Batch Processing of Message Transactions
[0088] As illustrated in FIG. 11, under certain conditions,
maintaining complete synchronization between the device 130 and
service 102 may consume a significant amount of wireless bandwidth.
For example, if a user has been out of range for an extended period
or time (e.g., the device is turned off) a plurality of messages
may be transmitted in succession from the interface 100 to the
wireless device 130 when the device is back within range. In some
cases, of course, the user may not necessarily be out of range at
all. Rather, the user may simply receive/ transmit a significant
number of e-mail messages is succession.
[0089] As illustrated, once the user begins viewing messages on the
device 130, message transaction updates are continually sent to the
interface 100. For example, when the user reads message 1, an
indication that the message was read is transmitted to the
interface 100. This may be followed by an acknowledgement from the
interface 100 (e.g., indicating that the communication was
received). Similarly, when the user reads and then deletes message
2, separate indications that the message was read and then deleted
are transmitted to the interface 100, respectively, followed by an
acknowledgement for each transaction.
[0090] Because each individual data transmission between the device
130 and the interface 100 may include a significant amount of
overhead (e.g., header information such as the device address 130,
the service address 102 and various other types of header/control
information), and because each message may require an
acknowledgement from the interface 100, synchronizing messages in
this manner may consume a significant amount of bandwidth. Put
another way, the ratio of actual data (e.g., database updates) to
control data (e.g., header data) will be relatively low. Moreover,
continual data transmissions of this type will tend to consume
significantly more power (e.g., because the device's radio will not
be idle long enough to enter its low-power mode).
[0091] Accordingly, in one embodiment of the invention, under
certain conditions (described below), data transactions between the
device 130 and the interface 100 are combined, or batch-processed
to conserve bandwidth. For example, as illustrated in FIG. 12, in
this embodiment, a plurality of message transactions are performed
on the data processing device before the device is synchronized
with the service 102. Subsequently, a single transmission 1201
containing all of the synchronization updates (e.g., message
viewings and deletions, message responses, . . . etc) is
transmitted to the interface 100, followed by a single
acknowledgement 1202 that the update was received.
[0092] Similarly, under certain conditions, database modifications
at the service 102 may be batch-processed before being transmitted
to the device 130. For example, if the user is in the office
reading through and responding to a series of e-mail messages
(e.g., from the client 110), transmitting each message transaction
to the wireless device 130 independently of one another may not be
efficient for the reasons set forth above. As such, in one
embodiment, these transactions (or a subset thereof) are combined
and concurrently transmitted to the wireless device 130.
[0093] As indicated in FIG. 12, the specific conditions under which
batch-processing is initiated and (once initiated) the specific
manner in which the messages are combined may be based on
processing parameters 1210, 1220 configured in the wireless device
130 and/or the interface 100, respectively. For example, in one
embodiment, batch processing will be triggered if the user has not
checked messages for an extended period of time (e.g., two days).
In this case, it is expected that once the user begins to check
messages he/she will perform a significant number of message
transactions within a relatively short period of time. It should be
noted, however, that various different batch-processing triggers
may be employed while still complying with the underlying
principles of the invention (e.g., two or more successive message
transactions within a predetermined period of time, manual
triggering set by the end user, . . . etc).
[0094] Once batch-processing is triggered, message transactions
occurring over periodic intervals (e.g., every 10 minutes) may be
combined and transmitted at the end of each interval.
Alternatively, or in addition, once the combined message
transactions reach some predetermined threshold (e.g., based on the
sheer number of transactions and/or the amount of data contained
within the combined transactions), the combined messages may be
transmitted together. Various other message combination parameters
may be employed while still complying with the underlying
principles of the invention.
[0095] One embodiment of a method for performing batch processing
of message transactions is illustrated in FIG. 13. At 1301, current
message transaction conditions are evaluated (e.g., the frequency
with which message transactions are performed, when the last
message transaction was initiated, . . . etc). At 1305 it is
determined whether the current conditions match the threshold
conditions required for batch processing. For example, as described
above, if the user's wireless data processing device 130 has been
out of range for a predetermined period of time and/or if the user
has not checked his e-mail for a period of time, the batch
processing mode may be invoked.
[0096] If the conditions are not met, then at 1310, the system
remains in standard message transaction mode. If, however, the
conditions have been met, then at 1315, the system (i.e., the
wireless device 130 and/or interface 100) processes messages
according to the established batch-processing parameters. For
example, at this stage the device 130 and/or interface 100 may
combine message transactions which occur over a predetermined
period of time (or which result in a specified number of
transactions or amount of data as described above).
[0097] At 1325 it is determined whether the standard message
processing conditions have once again been met. For example, if the
user's data processing device has been in range for a predetermined
period of time after entering the batch-processing mode, and the
user is periodically receiving and quickly responding to messages,
this may cause the system to revert back to the standard message
transmission mode. Depending on the system configuration, various
additional/alternative conditions may cause the system to enter its
standard message processing mode.
Multi-Level Batch Processing
[0098] In one embodiment of the invention, two levels of batch
processing are employed: one at the customer site 120 and another
at a data center located on the external data network 170. This
embodiment will be described with respect to FIG. 14 which shows a
data center 1410 communicatively coupled to the customer site via
an outbound gateway 1413 and to the wireless network 171 via a
wireless gateway 1411.
[0099] Batch processing logic 1400 at the customer site provides
the first level of batch processing. Specifically, in one
embodiment, when a user concurrently performs a group of message
transactions, the batch processing logic 1400 logically combines
the message transactions before transmitting them to the data
center 1410. For example, when a user deletes a block of e-mail
messages or moves a block of messages from one folder to another,
the block of individual deletions/moves are transmitted as a group
(i.e., as opposed to transmitting a series of individual
deletes/moves and waiting for an equal number of individual
acknowledgements form the data center 1410). In addition; the block
of message transactions are temporarily stored off in the remote
message cache 200 (described above with respect to FIG. 2), or in
an alternate cache at the customer site.
[0100] At the data center 1410, the batch-processed message
transactions are initially stored off in a secondary cache,
referred to herein as a "message switch" 1412. After receiving and
storing the block of message transactions, the message switch sends
a block acknowledgement to the batch processing logic 1400, which
may thereafter delete the block of message transactions from the
remote message cache 200. Alternatively, the batch processing logic
1400 may continue to store the block of message transactions for
some predetermined amount of time or after some predetermined event
has occurred (e.g., until it receives an indication that the
message transactions have been successfully received by the
wireless device 130).
[0101] If the wireless device is actively connected to the wireless
network, the message transactions are forwarded from the message
switch 1412 to the wireless device as a group (via the wireless
gateway 1411). For example, an indication that 10 messages have
been moved from the user's "inbox" to the user's "saved mail"
folder may be transmitted together. The wireless device 130 may
then respond with a single acknowledgement that it received all 10
message transactions. Alternatively, if one of the message
transactions had not been successfully received, the wireless
device 130 may request that individual message transaction as
opposed to the entire group (as described in detail below in the
section entitled "In-Order Delivery of Message Transactions").
[0102] In one embodiment, the message switch 1412 performs a second
level of batch processing functions in addition to (or in lieu of)
the first level of batch processing performed by the batch
processing logic 1400 at the customer site. Specifically, the
message switch 1412 batch-processes sequences of message
transactions generated over a period of time as opposed to the bulk
message transactions (e.g., "delete 10 messages") just described.
For example, a user will typically read one new e-mail message
after another at the customer site, and may continually add new
to-do list entries and calendar entries throughout the day. In one
embodiment, these individual message transactions are transmitted
from the interface 100 to the message switch 1412 as they occur at
the service 102. For example, when a user reads a single new e-mail
message, an indication that the message has been read is
transmitted to the message switch 1412. Similarly, when a user
generates a new calendar entry, the new entry is automatically
transmitted to the message switch 1412.
[0103] In one embodiment, the message switch 1412 groups the
various individual message transactions together before
transmitting them to the wireless device 130. If the wireless
device 130 is actively connected to the wireless network, the
message switch 1412 may group a certain number of message
transactions together and/or may group all message transactions
together occurring over a period of time before transmitting them
as a group to the wireless device 130. While the wireless device
130 is not actively communicating over the wireless network, the
message switch 1412 may combine all message transactions and
transmit them as a group once the wireless device comes online. In
one embodiment, the message switch 1412 and/or the batch processing
logic 1400 may batch-process message transactions based on the
batch processing parameters 1210 and 1220 described above with
respect to FIG. 12.
In-Order Delivery
[0104] In order to fully synchronize a wireless device 130 with a
service 102 as described herein, it is not only important that
message transactions are reliably communicated to and from the
wireless device but also that the message transactions are
communicated in the proper order (e.g., in the same sequential
order in which they occur at the service). For example, if a user
creates a new folder at the service 102 and then moves several
messages into the folder, the transaction creating the folder must
be received by the wireless device before the move transaction.
[0105] While wireless networks such as Mobitex ensure reliable
delivery of data, they do not necessarily ensure that the delivered
data arrives in-order. Moreover, while network protocols such as
the Transmission Control Protocol ("TCP") ensure in-order delivery
of data, these protocols assume that both the sending node and the
receiving node are always active and, therefore, are not
necessarily adapted to a system in which one of the nodes (i.e.,
the wireless device) is inactive for extended periods.
[0106] As such, one embodiment of the invention illustrated in FIG.
14, employs in-order control logic 1500, 1510 and 1520 at the
customer site, the data center and/or the wireless device,
respectively, to ensure in-order delivery of message transactions.
In operation, each message transaction at the customer site is
assigned a sequential code which indicates the relative order in
which the message transaction was generated. In one embodiment,
when a series of message transactions are transmitted to the
wireless device 130 (or transmitted from the wireless device 130 to
the interface 100), the wireless device 130 (or the interface 100)
will not execute a particular message transaction until it has
received all previous sequential message transactions. Thus, if the
wireless device 130 receives a series of message transactions coded
sequentially from 1 to 3 and from 5 to 10, it may execute message
transactions 1 to 3 but will not execute message transactions 5 to
10 until it receives message transaction 4.
[0107] In one embodiment, if the wireless device has not received
message transaction 4 after some specified period of time (e.g.,
because the message transaction was lost during transmission), the
wireless device 130 will send a request to the data center 1410
and/or the interface 100 to retransmit message transaction 4. The
in-order control logic 1500 or 1510 executed at the interface 100
and/or the data center 1410, respectively, will then retransmit
message transaction 4 from either the remote message cache 200 or
the message switch 1412, respectively.
[0108] The wireless device 130 notifies the interface 100 and/or
the message switch 1412 once it successfully receives message
transaction 4, thereby allowing the message transaction to be
removed from the remote message cache 200 and/or the message switch
1412 (i.e., assuming that other cache removal conditions described
herein have been met). In one embodiment, the wireless device may
send a block notification as opposed to an individual notification
for each message transaction. For example, rather than simply
sending a notification that it has received message transaction 4,
the wireless device 130 may send a single notification that it has
successfully received messages 1-10 (or some alternate number of
message transactions), thereby allowing all messages to be cleared
from remote message cache 200 and/or the message switch 1412 with a
single notification. It should be noted that the sequential
transaction numbers set forth above are for the purpose of
illustration only. Various alternate sequential codes may be
employed to indicate message transaction order while still
complying with the underlying principles of the invention.
Identification Code Allocation
[0109] Each e-mail message, calendar entry, to-do list entry, . . .
etc, is assigned a unique identification code by the service 102.
For example, if the service is Microsoft Exchange, a 128-byte
identification code is generated for each new data object.
Accordingly, when fully synchronizing a wireless device 130 to the
service 102, some mechanism must be provided to ensure that no
duplicate identification codes are assigned for two distinct data
objects. For example, if both the service 102 and the wireless
device 130 are capable of independently generating data objects,
they may both concurrently generate data objects with the same
identification codes, resulting in a conflict.
[0110] One mechanism for solving this problem is to require the
wireless device 130 to request a new identification code from the
service 102 each time it generates a new data object. One potential
problem with this scenario is that it may take an unreasonably long
time for the wireless device 130 to acquire the identification
code, depending on the speed of the wireless network. For example,
several seconds may be considered an unreasonable amount of time to
wait to begin entering a new e-mail message or calendar entry.
[0111] Alternatively, in one embodiment, the range of all possible
data object codes are divided between the wireless device 130 and
the service 103. In other words, a certain percentage (e.g., 1/2)
of all possible codes are allocated to the wireless device 130 and
the remaining possible codes are allocated to the service 103. In
operation, when a new data object is generated at the wireless
device (e.g., a new "to-do" list entry) the wireless device 130
will select a data object code only from within its pre-assigned
range, thereby preventing a conflict at the service 102. In one
particular embodiment, all negative codes are assigned to the
wireless device 130 and all positive codes are assigned to the
service 102. If a 32-bit (4-byte) code is used, this will result in
2,147,483,648 (2.sup.31) negative codes and 2,147,483,648
(2.sup.31) positive codes. It should be noted, however, that the
particular manner in which codes are divided up is not pertinent to
the underlying principles of the invention.
[0112] Another potential problem which exists when fully
synchronizing a wireless device with a service is that the standard
data object identification codes employed by many services are
unnecessarily large. As mentioned above, Microsoft Exchange
generates a 128-byte (1024 bit) code to identify each unique data
object.
[0113] Accordingly, in one embodiment of the invention illustrated
in FIG. 16, the interface 100 includes object identification code
mapping logic 1600 for mapping standard data object identification
codes 1620 (e.g., such as the 128-byte codes used by Microsoft
Exchange) to data object identification codes 1610 generated
specifically for use in the synchronization system described herein
(hereinafter "synchronization system identification codes"). As
illustrated, object identification code mapping logic 1600
maintains a data object identification table 1605 in which each
standard identification code 1620 is associated with a
corresponding synchronization system identification code 1610. As
described above, in one embodiment, the synchronization system
identification codes 1610 are 32-bits in length, thereby
significantly reducing the amount of information transmitted across
the wireless network. In addition, as indicated in FIG. 16,
negative identification codes 1610 identify data objects created by
the wireless device 130 and positive identification codes 1610
identify data objects created at the service 102 (e.g., from a
local desktop PC).
Data Object Conflict Resolution
[0114] Because copies of data objects may be maintained at both the
wireless device 130 and on the service 102, one embodiment of the
invention employs techniques to ensure that concurrent
modifications to the same data object at both the wireless device
130 and the service 102 are resolved in a logical manner. For
example, in one embodiment, a version number is associated with
each data object. Each time the data object is modified, the
version code is changed to indicate the new version.
[0115] In one embodiment, illustrated in FIG. 17, the interface 100
and/or the wireless data processing device 130 includes conflict
detection logic 1700 and 1701, respectively, for detecting when a
version conflict has occurred and conflict resolution logic 1710
for implementing one or more predefined conflict resolution
techniques to resolve the version conflict. By way of example, in
FIG. 17, a copy of Data Object X, Version 1 is initially stored on
both the wireless device 130 and the service 102. Version 1 may be,
for example, the initial version of a calendar entry or a to-do
list entry. Both copies of Data Object X, Version 1 are
concurrently modified at the service 102 and the wireless device
130 to generate Versions 2.sub.1 and 2.sub.2, respectively,
producing a version conflict. One way in which this may occur is
that a user modifies Data Object X at the wireless device 130 at
the same time as the user' administrative assistant modifies Data
Object X at the service 102. The wireless device 130 subsequently
attempts to update the service 102 with Version 2.sub.2 and,
likewise, the service 102 attempts to update the wireless device
130 with Version 2.sub.1.
[0116] In one embodiment, the conflict detection logic 1700, 1701
executed on the interface 100 and/or the wireless device 130,
respectively, detects the version conflict. In response, the
conflict detection logic 1700, 1701 triggers conflict resolution
logic 1710, 1711 which attempts to resolve the conflict by applying
one or more conflict resolution techniques. Various techniques may
be employed to resolve the conflict. For example, in one
embodiment, the version of the data object at the service 102
(Version 2.sub.1) is automatically retained, and the user is
notified that his modification of the data object from the wireless
device 130 will not be entered. The notification may be accompanied
by a visual indication of the new version (Version 2.sub.2) and/or
an explanation as to why the modification will not be entered.
Alternatively, in one embodiment, the user may be prompted from the
data processing device to select between the two potential
versions. Upon making a selection, the selected version will be
stored on both the wireless device 130 and the service 102. If
another individual attempted to enter the non-selected version
(e.g., the user's administrative assistant), then that individual
may subsequently be notified. In one embodiment, the version which
is selected is based on who entered it. For example, one embodiment
of the invention may be configured to always accept the version
generated by the user (i.e., and not the user's administrative
assistant). Thus, if the user modifies Data Object X from either
the wireless device 130 or directly at the service 102 (i.e., from
a desktop connected to the service 102), the user's modifications
will be accepted over any other modifications.
[0117] It should be noted that the specific conflict resolution
techniques described above are for the purpose of illustration
only. Various additional conflict resolution techniques may be
employed by the conflict resolution logic 1710, 1711 while still
complying with the underlying principles of the invention.
Full Wireless Synchronization and Zero Desktop Install
[0118] The advanced compression and message processing techniques
described above allow the wireless device 130 to be fully
synchronized with the service 102. For example, in one embodiment
of the invention, all major components of the messaging service are
completely synchronized on the wireless device 130. For example, if
the service is Microsoft Exchange, these components will include
e-mail, electronic calendar, contacts, tasks and notes.
Accordingly, all user transactions (message filings, to-do list
entries, . . . etc) are maintained up-to-date on the wireless
device without the need for a cradle.
[0119] In one embodiment, not only are messages synchronized, but
the entire state of the service 102 may be synchronized. This state
information may include, for example, the creation of new folders,
the deletion of old folders, filing of messages to folders, reading
a message from the device, marking a message unread, e-mail
deletions, arrival of new messages, copying of messages to a
folder, filing of messages and/or any other transaction which has
an effect on the mailbox maintained at the service.
[0120] In addition, in one embodiment, the wireless device 130 is
provisioned wirelessly. Thus, once a user's account has been
enabled on the service, all initial user data is sent wirelessly.
This data may include, for example, initial contacts (e.g. address
book), notes, tasks and calendar data. In one embodiment, a unique
encryption key may initially be installed on the wireless device
130 to encrypt communication between the device and the service
(e.g., by device installation software).
[0121] In one embodiment, even though the data on the wireless
device 130 is completely synchronized, an aging algorithm may be
employed to conserve space on the device. For example, at a given
point in time, the service may be storing 40,000 data objects
(e.g., e-mail messages, calendar entries, . . . etc), whereas, the
wireless device (having a limited amount of memory) may only be
capable of storing 20,000 data objects. Accordingly, in one
embodiment, the wireless device 130 will store data objects which
have not been modified or otherwise manipulated (e.g., moved from
one folder to another) for the longest period of time. In one
embodiment, the user may specify which types of messages should be
automatically deleted (e.g., only messages in the "sent mail"
folder, any messages over 1 month old, etc). Once a message has
been removed from the device, however, it may always be recovered
from the service.
[0122] For example, a user may request certain data objects to be
re-transmitted from the service 102 based on one or more specified
variables (e.g., creator, client, sender, recipient, date range, .
. . etc). Similarly, in one embodiment, if the user manipulates a
data object which has been deleted from the wireless device 130
from the user's desktop (e.g., moves an e-mail message from one
folder to another) that data object will be re-transmitted to the
wireless device and stored in the destination folder.
[0123] One embodiment of the invention maintains synchronization
events even if any part of the system is "down" (e.g., the data
network 170 and/or the wireless service provider network 171). For
example, as described above, any synchronization events which occur
during system downtime may be maintained in one of the batch
processing caches 1412 or 200 at the data center 1410 and/or the
interface 100, respectively. Thus, the interface 100 may be down
for a period of time, the data network 170 may be unavailable, the
wireless device 130 may be off, out of coverage or broken, and
synchronization updates will still be maintained. Once all parts of
the system are again working properly, the queued synchronization
updates are processed.
[0124] In one embodiment of the interface 100, "move" events are
detected and processed in an efficient manner. As indicated in FIG.
18 between the service 102 and the interface 100, when a message
(or other data object) is moved from one folder to another on
messaging systems such as Microsoft Exchange (e.g., from "sent
mail" folder to a "saved mail" folder, from the "inbox" folder to a
"read mail" folder, . . . etc), a new copy of the message is made
in the location of the destination folder and the original message
is then deleted from the source folder. Alternatively, the message
may initially be deleted from the source folder and then re-created
in the destination folder. Transmitting a delete command followed
or preceded by a copy of the underlying message to the wireless
device 130 is an inefficient way to perform move transactions.
Accordingly, as indicated in FIG. 18, one embodiment of the
interface 100 combines the "delete" and the "new" commands into a
single "move" command using the data object (i.e., message)
identification code, the source folder and/or the destination
folder, thereby significantly reducing the amount of information
transmitted across the wireless network.
[0125] In order to provide a move command to the wireless device
130 in this manner, the system (e.g., the interface 100) must first
identify the message which is to be moved. One embodiment of the
interface identifies the message using the methods set forth in
FIG. 19a and/or FIG. 19b, either alone or in combination. Referring
initially to FIG. 19a, at 1900 the interface 100 detects that
Message X has been deleted from Folder A. At 1910, the interface
100 attempts to determine if the deletion forms part of a move
command. As such, it searches other folders in the user's account
to locate the same message. If it finds the same message in a
particular folder, e.g., Folder B, it transmits a move command to
the wireless device 130 at 1930 indicating that Message X should be
moved from Folder A to Folder B. If, however, it does not locate
Message X in another folder, it transmits a delete command to the
wireless device indicating that Message X should be deleted from
Folder A.
[0126] Referring now to FIG. 19b, in one embodiment, the interface
100 initially detects that Message X has arrived in Folder B. In
response, the interface 100 searches the table of data object
identification codes 1605 (see, e.g., FIG. 16) to locate a match
for the identification code associated with the Message X. If a
match is found (determined at 1970), then the interface 100
transmits a move command to the wireless device 130 indicating that
Message X should be moved from Folder A to Folder B. If, however,
the interface 100 does not locate an identification code match, it
transmits a delete command to the wireless device indicating that
Message X should be deleted from Folder A.
[0127] When a wireless device 130 has been "out-of-touch" with the
service 102 for an extended period of time, a significant number of
transactions may have accumulated which need to be synchronized.
Accordingly, in one embodiment, in the interest of both saving
bandwidth and time on the device (e.g. not swamping it with
unsynchronized data), only representative portions of some data may
be transmitted. For example, if the wireless device 130 has been
off for two weeks, only message headers may be transmitted to the
device (i.e., not the message bodies). The underlying reason for
this is that the user will not likely want/need to read all of the
older mail on the device.
[0128] In one embodiment, the specific manner in which data is
transmitted to the device after an extended period of time may be
selected by the user. Thus, the user may select a period of time
after which only headers should be sent (e.g., older than 1 week,
never, etc). In any case, the user may still request the full
messages bodies after the headers have been transmitted.
[0129] As used herein, "zero desktop install" refers to the ability
of the wireless device 130 to function normally without the
installation of any client software on a user's desktop computer.
One embodiment of the invention does not require a desktop because,
as described above, all messaging features (e.g., management of
device options, configuration of the messaging service, message
filters, outgoing e-mail signatures, security settings, . . . etc)
may be accessed by the wireless device. This feature is not
available in current messaging systems because current wireless
devices support only a subset of all messaging functions. As such,
current systems require desktop software and a cradle to complete
the synchronization process.
[0130] In one embodiment, the wireless device's configuration
settings are stored and continually updated on the messaging
server. Accordingly, if the device settings are ever lost (e.g.,
because the device is initialized or lost) the settings may be
automatically recovered along with the messaging data. In fact, in
one embodiment, the device does not ever need to be backed up
because there is no data unique to the device that isn't
synchronized to the messaging server.
[0131] In addition, in one embodiment, software upgrades are
transmitted wirelessly to the device, thereby completely removing
any required link between the device and a desktop. Software
upgrades may include upgrades to the device's operating system as
well as application installations.
[0132] Embodiments of the invention may include various steps as
set forth above. The steps may be embodied in machine-executable
instructions. The instructions can be used to cause a
general-purpose or special-purpose processor to perform certain
steps. Alternatively, these steps may be performed by specific
hardware components that contain hard wired logic for performing
the steps, or by any combination of programmed computer components
and custom hardware components.
[0133] Elements of the present invention may also be provided as a
machine-readable medium for storing the machine-executable
instructions. The machine-readable medium may include, but is not
limited to, floppy diskettes, optical disks, CD-ROMs, and
magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, magnetic or
optical cards, propagation media or other type of
media/machine-readable medium suitable for storing electronic
instructions. For example, the present invention may be downloaded
as a computer program which may be transferred from a remote
computer (e.g., a server) to a requesting computer (e.g., a client)
by way of data signals embodied in a carrier wave or other
propagation medium via a communication link (e.g., a modem or
network connection).
[0134] Throughout the foregoing description, for the purposes of
explanation, numerous specific details were set forth in order to
provide a thorough understanding of the invention. It will be
apparent, however, to one skilled in the art that the invention may
be practiced without some of these specific details. For example,
while illustrated as an interface 100 to a service 102 executed on
a server 103 (see FIG. 1), it will be appreciated that the
underlying principles of the invention may be implemented on a
single client in which the client transmits data over a network.
Moreover, although described in the context of a wireless data
processing device, the underlying principles of the invention may
be implemented to compress data in virtually any networking
environment, both wired and wireless. Accordingly, the scope and
spirit of the invention should be judged in terms of the claims
which follow.
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