Note: Descriptions are shown in the official language in which they were submitted.
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METHOD. AND APPARATUS FOR
RATE GOVERNING COMMUNICATIONS
Field Of The Invention
The present invention relates to communications and more
particularly an improved method and apparatus for transferring data
l0 in a communications system.
Background
The fast 10 years have seen a tremendous increase in the
demand for communications services, including both wired and
wireless networks capable of handling data communications. Unlike
real-time voice services, such as standard telephony or cellular
wireless services, in which circuit-switched communications are
used because of the sensitivity of users to the timing of oral
diaiogue/voice data, greater efficiencies can often be achieved in
non-voice data communications through the use of packet-~vvitched
or .hybrid communications systems. This is particularly the case
with communications to remote users (e.g., persons sending
messages via one of the well-known available wireless networks
like GSM (Global System for Mobiles) or AMPS (Advanced Mobile
Phone System) cellular), where protracted circuit-switched sessions
into a mail server or LAN (local area network) could be prohibitively
expensive due to the high per-minute session charges by the wireless
service provider.
One solution to this problem has been for users to limit, as
much as feasible; their comr~nunications to sessionless
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communications. This can be done, e.g., by subscribing to additional
email services that can receive LANIWAN (wide area network) email
and send out broadcast pages and transmissions to registered users,
in lieu of requiring a user to maintain a session with a mail server.
However, this disadvantageously requires subscription to an
additional service, and is typically limited in the types -of
applications supported. With the rapid, growth in emerging session-
oriented applications--tike the popular client server application of
Lotus Notes~--the need is growing for more cost effective solutions
to providing connectivity of such session-oriented applications and
' users remotely located from their host servers.
Regardless of whether a session-oriented or session-less
communication service is used, it is also desirable to limit the
amount of information communicated between a remote user and
host, both to save off-site user's time and ~to limit the costs arising
from the more expensive rates for remote communications.
Unfortunately, typical applications like email do not provide for
user-selected methods for choosing and limiting the volume of down-
loaded communications, or for filtering uploaded or downloaded
communications. Thus, a user who wants to receive remote
messaging is left with an option of receiving all his messages (or
some summary thereof), even 'the ones he or she might otherwise be
willing to leave unprocessed until a later time when no longer using
expensive remote communications services. Further, many
processes, like that of a typical email reply, are wasteful of
bandwidth by resending all earlier messages each time a new reply is
generated, even though the earlier messages may still be stored at
both ends of the wireless network.
' In addition to the above concerns over how to optimize the
types and amount of data being transferred, there is additionally a
problem in a lack of effective techniques for monitoring and even
controlling an aggregate use of tariffed networks. While the network
service providers have means for tracking use by an individual unit
~
CA 02365520 2002-O1-09
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basis, which is totaled in periodic billing statements, this
information is typically unavailable to users or their
managers/application administrators. Thus, users and managers are
typically left without any effective means for controlling the level
of messaging during a billing cycle, and can only monitor or react to
usage following the service providers periodic statements.
There remains therefore a need for an improved means for data
communications that solves these and related problems.
Brief Description Of The Drawings
FIG. 1 is a block diagram of a communications system according
to a first embodiment of the invention;
FIG. 2 is a block diagram of a communications system according
to a further embodiment of the invention;
FIG. 3 is a flow chart illustrating virtual session data transfer.
between the different functional entities of the wireless
communications system of FIG. 2;
FIG. 4 is a flow chart illustrating a pre-stage filtering
embodiment for data transfer between the different functional
2o entities of the wireless communications system of FIG. 2;
FIG. 5 is a flow chart illustrating one embodiment of pre-stage
filtering for data transfers;
FIG. 6 is . a flow chart illustrating another embodiment of pre-
stage filtering for data transfers;
FIG. 7 is a flow chart illustrating a message summarization and
selection embodiment for data transfer between the different
functional entities of the wireless communications system of FIG. 2;
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FIG. 8 is a diagram illustrating an embodiment of a summary
index for use in the process of FIG. 7;
FIG. 9 is a flow chart illustrating an optimized reply
embodiment for data transfer between the different functional
entities of the wireless communications system of FIG. 2; and
FIG. 10 is a flow chart illustrating a rate governor embodiment
for data transfer between the different functional entities of the
wireless communications system of FIG. 2.
1o Detailed Description
These problems and others are solved by the improved method
and apparatus according to the invention. A presently preferred first
main embodiment of the invention is a system including a virtual
session manager (VSM) for establishing and maintaining a
sessionless communication path with a first data processing device
(e.g., a mobile client) on the one hand and a session-oriented
communication path with a second data processing device (e.g., a host
system). The session-oriented communication protocol (including
network and application layer protocols) with the host system
permits remote access to, e.g., LAN-based applications, while the
virtual session, via a sessionless-oriented communication protocol,
between the VSM and remote (i.e., coupled via a tariffed network or
connection) client permits this access to be carried out without the
expense of a dedicated/circuit switched connection.
In a second main embodiment, a prestage filter stage is
provided for applying user-definable filter parameters (e.g., reject,
pass, or granularity filters) on data being transferred between the
remote communication unit and communication server. For
downloading, e.g., email from a host post office, a communication
3o server controller preferably either forwards the filter parameters in
a query object or message to the post office to apply and return
' CA 02365520 2002-O1-09
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qualified mail, or the communication server receives all unprocessed
mail and applies the filters locally, only acknowledging as processed
that mail which is qualified. For uploading, e.g., email from a client,
a client controller applies an upload prestage filter so as to retain
all filter rejected mail, while transmitting mail passing the filters.
Thus, only desired data transfers (i.e., those meeting user defined
filters) are communicated over the expense-bearing networks
between the remote unit and communication server.
In yet another main embodiment, a select and summary (S&S)
listing or index is used to provide user flexibility in reviewing and
requesting otherwise filtered data. Both the user's remote
communication unit and communication server maintain a S&S index
containing identifying (summary) information about data which has
not been fully transferred between the communication unit and
communication server. As new data is reviewed and filtered for
transfer, identifying/summary information is captured for any non-
qualifying data by either a host unit or the communication server.
This information is stored in the communication server's S&S index,
and at least periodically, or upon request, transferred wia update
2o messaging to the remote communication unit. Upon reviewing its
updates or its S&S index, the user may send a request for such of the
data that it desires partial or full transfers for further review.
Thus, a cost efficient review mechanism is provided to users for
determining whether to transfer data that otherwise fails selected
filter parameters.
In a fourth main embodiment, a method and apparatus for
optimized reply to messaging is provided. When sending a reply, the
remote communication unit's controller generates a delta (e.g., data
representing the content difference between two messages) between
3o a preceding message and the reply message, and forms an optimized
reply using the delta and an identifier of the preceding message. On
receiving the optimized reply, the communication server uses the
data unit identifier to retrieve the preceding message from a further
- CA 02365520 2002-O1-09
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host (e.g., the post office mailbox of the user associated with the
remote unit), reconstructs the full reply from the retrieved message
and the delta, and forwards the full reply to the addressee. When
receiving a reply for the remote unit, an index is preferably
maintained at both the remote unit and communication server of mail
stored at the remote unit. Resort is made to this index to determine
a preceding message forming part of the reply. An optimized reply is
similarly formed from a delta and identifying information of the
preceding message, and sent to the remote unit. In this manner, the
volume and expense incurred in reply messaging is greatly reduced,
by only sending a delta and small header (i.e., the identifying
information).
Finally, in a fifth embodiment, a rate governor is provided for
monitoring and controlling the amount of communications between
the remote unit and communication server. Preferably, as
thresholds) are passed a user is alerted to amounts (time andJor
charges) spent or remaining, and once a use limit is reached further
communication is restricted. A main rate governor is maintained at
the communication server, allowing access, control and the like by
system administrators and the like. A further rate governor,
responsive to the main rate governor, may also be used at the remote
unit. By means of this rate governor a mechanism is provided for
both limiting user or group data transfer beyond a set amount, as
well as providing alerts to users as the limit is approached.
Turning now to FIG. 1, there is generally depicted a
communication system 100 in accordance with a first embodiment of
the invention. This system is configured to support one or more user
devices such as wireless subscriber units (i.e., mobile station (MS)
105) communicating with host processor 115 via an infrastructure
including base station 120 and intermediate system 125 coupled to a
data network 130. In the illustrated case mobile station 105 ~is a
portable computer having an rf (radio frequency) modem 106. A
communications server 110, including a virtual session manager
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(VSM) and query manager (QM), is coupled between the public data
network 130 and the host server 115. The virtual session manager
and query manager are, preferably, an appropriately configured data
processing device, the VSM and QM program being shipped for loading
on the server 110 via any convenient means such as a machine-
readable CD-ROM 111 (compact disc-read only memory) or the like.
Counterpart client-communications software, e.g., a prestage filter,
can be shipped via a similar convenient form like CD-ROM 107,
downloaded directly from server 110 to subscriber 105 (also being,
1o e.g., a data processing device, by which is meant virtually any
processor (but not a human) capable of processing data for a
programmed result, whether a general purpose computer or more
specialized electronic processor), or the like.
In this embodiment the mobile user 105 communicates with the
server/VSM 110 using any appropriate data protocol being used by
the data network 130, as necessarily modified for transport over the
wireless infrastructure; the wireless infrastructure could be, e.g.,
any private system like ARDIS~ or DataTAC~, CDPD (cellular digital
packet data), GPRS (GSM Packet Radio Service), and the like. Thus, a
sessionless data flow between the mobile user 105 and server/VSM
110 occurs on an event driven basis, and no costly connection is
maintained when there is nothing being communicated. In order to
keep connectivity costs to a minimum, the server 110 is preferably
connected to the LAN/WAN on which the host 115 is also connected,
via any standard LAN/WAN communication channel (e.g., a bus or
backbone). This allows the communications server 110 to
advantageously maintain the same session with the host 115 that the
client 105 typically enjoys when connected to the LAN/WAN. Thus,
by use of the server 110 the client 105 can achieve a virtual session
with the host 115 with almost the same access as if directly
connected to the host's 115 LAN, but at a substantial reduction in the
cost of communicating via the wireless network and PDN 130.
CA 02365520 2002-O1-09
FIG. 2 illustrates an alternative communication system 200
embodiment of the present invention. A first client, a mobile end
system (M-ES) computer including a user device 201, is in
communication with a base station (BS1 ) 218 of a wireless
communication system. This base station 218 is coupled, e.g., on a
same bus or via bridgeslrouters, to a communication server 220
which includes VSM 230. An electronic mail (email) post office is
coupled locally to VSM 230, either as another program running on the
same communications server 220 or located on another server 240 of
i0 the communications server's 220 LANI1NAN. It is not important,
however, where the post office is located for purposes of operation
of the VSM 230, as is illustrated by other application hosts B and C
255, 260 being ~ in .communication via other networks such as a public
data network or public switched telephone network 250. In fact, the
same user 207 could be concurrently coupled via the VSM 230 to, for
example, a local email post office 240, a remote client-server host
255, a further database host server (not shown), an administrator
host server 260, a multimedia host, a voice processor, etc, it should
be understood that for purposes of this application, a first device or
2o component is responsive to or in communication with a second unit
or component regardless of whether the first and second units are
directly coupled or indirectly coupled, such as via intermediate
units, including switches that operatively couple the units for only a
segment of time, as long as a signal path can be found that directly
or indirectly establishes a relationship between the first and second
units. For example, the client computer 105 is in communication
with the VSM server 110 even though intermediate system (e.g., a
router or switch) 125 and a packet network 130 having multiple
switches etc. are disposed between the user device 105 and VSM
server 110.
In the illustrated case client 201 includes a data transfer
manager or exchange unit 206, which in simple form could be an
appropriately programmed electronic processor 207 (e.g., a general
purpose CPU (central processing unit) and memory or data store 211.
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A timer 205 is also preferably employed in the data exchange control
process, as will be explained further in connection with the flow
chart of FiG. 3 below. A typical client 201 would also include some
forms) of user interface such as display 204, a data
encoderldecoder 203 to accommodate the system' communications
protocol(s), and a transceiver (if using rf or infrared
communications) and a modulator-demodulator (or modem) 202 to
connect to a wireless or wireline communications network.
Transceiver/modem 202 in this case would either include a built-in
to or attached user module for wireless LAN communications; the
specific type will vary depending on the system, e.g., including
PCMCIA (personal computer memory card interface association)
wireless modems, and attached or built-in PSTN (public switched
telephone network) modem, etc. Specific features of data exchange
unit 206 preferably includes (as more fully described below) a
prestage filter (PSF) manager 208, rate governor (RG) 209, user
profile store 212, select and summary index store 213, and mail
store 214 (a store being any available device (e.g., ROM (read-only
memory), disks) or program (e.g., a database) for storage of the
specified information).
The communication server 220 preferably includes a data
transfer manager or controller 229 having a VSM 230, memory stores
for storing active client profile (user parameters) and inactive client
profile information 226 and 227, a timer 224, and optionally some
form of protocol translators or formatters 222. The VSM 230 serves
to manage the virtual session with the client 201 and session with
host systems 240, 255 andlor 260 based on the parameters loaded
into the active user parameter storelprofile memory 226 or object.
Controller 229 preferably also includes a query manager (QM) 231 for
3o controlling specific processes (e.g., sending messages to a post
office to query for unprocessed messages and forwarding received
messages etc.), and a prestage filter 232 and rate governor 234.
Memory 225 also preferably includes a client select and summary
index database or store 228, which will also be described more fully
CA 02365520 2002-O1-09
below in connection with FIGS. 7 and 8. The protocol translators 222
serve to format or code the messages as appropriate for transport
between the VSM 230 and client 201; these include, e.g., appropriate
protocol software that can be located at the communications server,
5 or any other convenient processor per design of the given
communication system. By messages is meant any appropriate data
unit (whether a frame, datastream, packet, or other format),
including objects, datagrams, etc., for containing information being
communicated.
l0 Communications server 220 is also illustrated as supporting
additional users, e.g. user module 216, communicating via different
access points, e.g., control module (CM) 217 of a wireless LAN and
base station 219, all access points 217-219 being coupled via a
common bus, backbone, etc. These base stations can be part of the
same communication system, similar systems owned by different
service providers, or even different systems, all of which may be
different from the communications server service provider. Thus,
for example, a single communications server can support at one local
region 215 an ARDIS~ node, a RAM~ node, a wireless LAN controller
module, a CDPD node, an in-building cordless telephone node, etc.,
allowing users from a variety of systems to access the same
communications server and post office. Users not registered could
access through the appropriate one of these nodes along the model of
FIG. 1, i.e., via PDN 250 to a remote communications server having
their VSM/QM. Thus, any number of system configurations is
possible, limited only by the network services provided and the
user's preference.
A process by which a VSM manages communications between
client and host is illustrated in the flow chart embodiment of FIG. 3.
This process typically begins with a user event, such as instantiation
(forming) of a communications object at the client and sending a
registration message (steps 301-302). Alternatively, the
infrastructure could initiate the communications by sending a page
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or the like requesting the client to register (for example, when the
client has registered with the wireless system but not yet requested
registration with the communications server). In any event, once a
registration message is received by the communications server, it
preferably authenticates and otherwise qualifies the client,
including sending a logonlregistration message to the host for its
authentication of the client (steps 303-305). Upon successful
authentication, the communications server instantiates a client
object (CO) for the communications session including client
parameters retrieved from an inactive client parameter store, as
modified by the user in his registration or subsequent messages
(step 306). These parameters include at a minimum client and host
identifiers, but may also include additional preferences based on the
type of communications involved. Also, the registration and
authentication process can be handled by the VSM, or alternatively by
another appropriately programmed entity of the communications
server. Following instantiation at the server, a response message,
e.g., a further registration message, is sent to the client, and an
acknowledgment (ACK) returned to the server; both client and server
then retain the instantiated objects as fully ~ qualified, and may start
session timers (steps 307-309). At this point a virtual session has
been established between the client and the VSM, and a regular
session established between the VSM and host computer. If the
registration is not successful; then any instantiated object is
deleted, with the client returned to an inactive status.
Upon establishing the virtual session, a query is preferably
generated by query manager requesting unprocessed data for the user,
and the VSM forwards the query to the host (step 320). In the case of
email, e.g., this might include generating a request message for all
unread mail in the users post office box. The post office then checks
for new mail received, and forwards all such mail to the VSM (steps
321-322}. Because the VSM has established a LAN session with the
post office, these communications are performed relatively quickly,
e.g., in accordance with the LAN's and host's typical processing for
CA 02365520 2002-O1-09
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their current loading level. The VSM in turn forwards the data (i.e.,
mail) received via the virtual session transport (step 323). For
example, in the case of FIG. 1 where PDN 130 is an ISDN (integrated
services digital network) network connected to a CDPD wireless
network, the mail would be appropriately packetized by the
communications server and delivered via the serving BS 120
according to ISDN/CDPD system protocols. This can take up to
several minutes or more for a moderately sized mail package.
However, since the data is being delivered in a sessionless mode, the
amount of time the communication channel (including the more
expensive wireless communication channel portion, as well as the
portion via PDN 130) is tied up is kept to a minimum. This also
translates into a significant cost savings for the user, since the user
is only charged on a per packet basis for mail when it is actually
transported, and doesn't have to pay for a prolonged session to keep
connected to the post office in order to receive new mail. Finally,
upon receipt by the client, appropriate acknowledgments are sent and
the post office box updated, e.g., by marking the mail as read or
processed (steps 324-326)
2o While in some systems it may be advantageous to store some of
the data at the communications server, in the case of email and the
like it is presently envisioned that the communication server is
preferably used in maintaining the sessions between client and host,
and not as a remote server for the host. Thus, rather than have all
new data from the host pushed down to the communications server,
most data exchanges are preferably initiated, at some predetermined
interval or intervals, by the communications server (e.g., by the query
manager).
Further, it is an inefficientuse of resourcesto
continue
3o querying a host attempting deliver data the client
or to when is no
longer receiving at its remote when the
location
(occurring,
e.g.,
client leaves a coverage the user turns its modem or
area, or off
processor). Thus, a process either maintainingthe client
for in an
- CA 02365520 2002-O1-09
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active status, or removing the client from active status in response
to an event, is also preferably included in the VSM. One such process
is to utilize timers at both client and VSM to determine when a
virtual session is no longer active. The timers are first set upon
registration, and are subsequently reset after each data exchange
(steps 327-336). If no data exchange occurs within a predetermined
period of time, say 20 minutes, both client and VSM would remove
the client qualification (i.e., destroy the client object for the
communication session) and, if desired, mark the client as being in
l0 an inactive status (steps 337-340). The VSM would also forward a
logoff message to the host (step 341 ). In order to avoid an undesired
time out, the client is preferably configured to send a short. message
after a predetermined period since the last data exchange,
sufficiently prior to the time at which the timers elapse so that the
VSM can receive it. Otherwise, if there are only intermittent data
exchanges, the client may be required to frequently re-register; this
in turn means the client will not be notified of outbound data until
the client re-registers and is again coupled via the virtual session
manager.
Turning now to FIGS. 4 through 6, a presently preferred
embodiment is shown for prestage filtering data for transfer
between the different functional entities of the wireless
communications system of FIG. 2. This typically begins with the
generation of a query object or message at the communications
server (step 406). This object/message may be created in response
to a preceding client generated message (e.g., a request generated
when clicking on an application button requesting updates, executing
the mail application, etc.), or in response to settings in the client
profile. However, after updating the active client profile/object for
3o an active client application; the query manager is preferably
programmed to send query objects at predetermined intervals for
each application being run by each active client, the intervals varying
depending on the application type or administrator preference (e.g.,
for mail about every 10-30 seconds or longer). Alternatively, the
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intervals could be user specified via the client profile, for example
to shorten the query intervals for time critical applications (e.g., for
emergency services or "real time" applications) , or lengthen the
intervals when less frequent updates are desired (e.g., to conserve on
traffic expenses for updates to a rapidly changing, but non-time
critical, group-ware file or document).
The content of the query objects will vary depending both upon
the application and client filter settings. One approach for mail
applications is to have a predetermined number of user-definable
1o filter attributes stored in the client profile databases (e:g., stores
212 and 226-227 of FIG. 2). These attributes can include, by way of
example, the priority of a message (e.g., urgent, normal, or low); the
date on which the message is sent or posted; the size of the message
(typically uncompressed, i.e., the normal stored size; although
transmission size or cost could also be used); the author of the
message; and the subject of the message (e.g., key words in a subject
line or in the text). These attributes can simply be used as reject
criteria (e.g., reject all messages having "low" priority, date before
"12/15/95", size more than "2" kbytes (kilobytes), or subject not
2o containing "project x"), pass criteria (all messages from "Boss") or a
combination of both, the variety and complexity being a matter of
design choice. These attributes also preferably include certain
"granularity" filters, i.e., filters additionally limiting the size of a
message passing all or most of the other filters. Three possible
examples of granularity filters are a truncation size filter (e.g.,
truncate the message after . the first "100" bytes), and text or file
attachment filters (e.g., indicating whether or not to strip
attachments). Thus, messages passing all criteria but message size
could still be received in a truncated size meeting the message size
3o criterion. Alternatively, messages failing the author or subject
filters could still be passed with header information, by setting all
rejected messages to be passed with a text truncation size of "0"
bytes. One skilled in the art will appreciate that a variety of other
reject/pass filter criteria may be used, and the specific ones and
CA 02365520 2002-O1-09
combinations of user-definable (or even administrator-definable)
features will be largely a matter of design choice depending on
factors such as the desired functionality, complexity, and
applications) (including filterable features). It is significant,
5 however, that clients are now provided by the present invention with
a means for effecting prestage filtering of their communications by
virtue of the communications server and definable filter-settings,
rather than having to choose between receiving no messages or
receive all messages, including less important or expensive and
10 time-consuming transmissions.
The prestage filtering is preferably performed at the host
server. This may be accomplished, for example, 'by passing the filter
attributes in an appropriately formatted query object or message for
use by the host application. In the illustrated case a query object
15 with the client filter settings is forwarded to the post office; and
applied by a communications server object or CSO (instantiated at
the post office when the virtual session is established). The post
office/CS0 reads/queries the query object for the filter attributes,
and applies these criteria in the selection and formatting of
2o unprocessed messages (steps 408-412). The filtered messages are
then encapsulated and forwarded to the QM, which similarly forwards
the filtered messages (with appropriate protocol translation) to the
client (steps 414-416). Alternatively, where the host application is
not designed to permit prestage filtering, all unprocessed messages
can be forwarded to the communications server, where the filters
are applied via a prestage filter (PSF) object or routine (e.g., PSF 232
of FIG. 2), with only qualifyinglfiltered messages being forwarded to
the client (steps 410, 418-424). Through acknowledgments. the post
office is notified how to mark the mail index in both cases. For
3o example, when prestage filtering at the post office, all forwarded
mail would be marked as processed/read and all filtered mail as
unprocessed (truncated messages being marked as either depending
on design conventions, or if available marked as filtered or partially
processed). If prestage filtering is done at the communications
- CA 02365520 2002-O1-09
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server only those messages forwarded to the client would be
acknowledged and marked as processed (step 428).
In addition to downloadldownlink filtering, prestage filtering
is also advantageously used in upload/uplink transmissions. This can
take the form of granularity filtering, or automatically retaining the
whole data unit or message based upon filterable attributes for later
transmission when on a lower cost network. In this case, each client
would have a prestage filter (PSF) unit such as that of PSF 208 of
FIG. 2 (e.g., a PSF object or routine drawing on selected attributes in
1o the profile store 212). Each data unit generated is filtered using the
user-selected criteria, with qualifying data being forwarded via the
communication server (steps 430-436). If a data unit is not sent, it
is retained locally for transmission later, e.g., when connected via a
lower cost network to the post office. As an enhancement, the user
could additionally be provided with a selection of types of send
buttons (i.e., filtered send or unfiltered send), or be prompted with an
alert dialogue or similar message when a message is filtered to
decide whether to forward the data unfiltered (steps 438-440).
Similarly, the user can be provided with several groups of filter
2o settings that could be manually or automatically activated, so as to
enable the client to adjust plural filter settings with a minimum
effort, for example by switching to a more restrictive profile when
entering important meetings (which profile could be automatically
activated via an appropriately configured and coupled calendar
program, etc.).
While only the client need retain the upload filter attributes in
its profile store, preferably both the communication server and
client store copies of the download filter settings in their profile
memories. This conveniently permits a client to review all settings
3o whenever desired, and to change the settings locally. When the
download settings are changed at the client, the changes are
communicated to the communication server preferably as soon as the
change is made, or as soon as a virtual session is established if the
CA 02365520 2002-O1-09
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changes are made while offline from the communication server
(steps 442-444). Further, where a summary index of filtered
messages is maintained (as is described in connection with FIGS. 7
and 8 below), upon a change in filter settings the communication
server may be automatically set to forward all messages previously
rejected but now passing the new filter settings.
FIGS. 5 and 6 illustrate two approaches to prestage filtering
particularly useful for email filtering. In FIG. 5, a series of five
reject filters are applied to each message. If a mail message does
not meet any of the criteria (priority, date, size, author, or
subject/key word) then it is left unprocessed (steps 502-516). Once
all unreviewed messages (i.e., all unprocessed messages, or if
expanded marking is available all unprocessed messages not
previously filtered) have been filtered, those not rejected are
forwarded (step 518). FIG. 6 illustrates the application of
granularity filters. If a message exceeds the filter size, it is
appropriately truncated (including insertion of a note indicating
truncation) (steps 602-606). Similarly, if there are text or file
attachments, and these are marked to be filtered, they are stripped
with, optionally, a note being inserted alerting the addressee that
the attachment was stripped (steps 608-614). Once filtered, the
message is sent (step 616).
FIGS. 7 and 8 illustrate a further enhancement, permitting the
user to more conveniently review selected information even for
filtered/rejected data. In the preferred embodiment a query object
or message is similarly generated by the communication server as
described above. However, in addition to the profile information, the
query object in this case includes a request for summary information
about each partially and fully rejected message (step 702). When the
host (i.e., a post office server in the illustrated case) receives the
query it applies the appropriate filters; if only qualifying mail is
present, this is forwarded to the client as described above (steps
704-708). Where there is partially (e.g., truncated) or fully rejected
' . CA 02365520 2002-O1-09
data, identifying summary information is captured for all rejected
data (step 710). For mail this identifying summary information
would include the message serial number, along with certain header
information (801 and 802 of FIG. 8). This header information may
5 include any filterable attribute (e.g., date, author, subject, size,
priority, attachment indicator) and is preferably client definable, so
the client can decide how much header information it needs and how
much to omit. All qualifying and non-qualifying (i.e., filter-rejected)
mail is marked similarly as described above (step 712).
1o When the response object or message is received by the QM of
the communication server, the encapsulated identifying summary
information is saved to a select and summary (S&S) index, such as
that illustrated by client S&S index database 228 of FIG. 2 and the
index structure of FIG. 8. This index is preferably created in
response to the first query following full qualification, although one
could retain a stored index when the client is inactive as long as the
index is fully updated upon re-registration/ qualification. In order to
minimize transmissions between the communication server and the
client, only changes to the S&S index are forwarded, as summary
delta data (i.e., a delta of the revised index to the immediately
preceding index, the preceding index being an acknowledged version
same as that stored in the S&S index (e.g., S&S index database 213 of
FIG. 2) of the client). Where only identifying summary information is
received in response to the query object, one may additionally delay
forwarding the delta information to the client for a predetermined
period of time or until the next message passing the prestage filters
is forwarded, whichever comes first (i.e.; the filter-rejected
information more likely being less important, some users may prefer
to receive S&S index updates less frequently in order to further
reduce costs or interruptions) (steps 714-718).
Upon receiving the delta of the identifying summary
information, the client updates its S&S index and, when appropriate,
prompts the user (again, the prompt criteria could be set for ali
CA 02365520 2002-O1-09
19
messages, or some sub-set based on any filterable attribute, etc.).
The user is thus able to review the summary information and make a
determination on whether or not to override the filter rejection. For
mail the user wants to read, the user indicates the decision by any
appropriate means (clicking on the message, voice command, etc.) and
an appropriate request generated (e.g., for all selected mail, for only
a partially filtered version (e.g., truncated}, etc.) (steps 72~-722).
The request is appropriately translated, as needed, and sent as a
query object or message to the post office: Upon retrieval, the
requested data is forwarded to the client via the QM. Upon receipt at
the client, a read acknowledgment may be generated and sent to the
communication server. Preferably when the read acknowledgment is
received at the communication server a further ACK
(acknowledgment signal) may be sent to the client, at which time
both client and communication server update their respective S&S.
indices to remove the entry for read mail from the S&S index, and
note any partially read mail. Upon acknowledgment, the post office
may further mark any read mail as processed (steps 724-734).
As with prestage filtering, one skilled in the art will
appreciate that many more filterable attributes and summary inputs
are possible than those described, and which ones are available will
depend on such factors as the desired functionality, complexity, and
application (s) (including filterable features) for which the select and
summary index is being used. The index structure may thus similarly
vary significantly, as will the means for achieving similar indices
for both the client and communication server; in other words, while
one could simply periodically forward the whole index, where
practical any one of a number of known delta (e.g., data representing
the content difference between two files) or other update approaches
for communicating less than the whole index are likely more
preferable. What is significant, no matter the particular design
approach selected, is that a summary index, showing unprocessed or
partially processed data (e.g., that filtered), is available to a client
for determination on whether to process the data further, with a
CA 02365520 2002-O1-09
substantially identical index being retained at the communication
server in order to further reduce transmission requirements.
FIG. 9 illustrates a yet further improvement, this embodiment
permitting a user to minimize the data transmitted for responses to
5 earlier data ~ transmissions. This is particularly advantageous in the
case of email, where it is common to append all prior messages in an
email conversation to a reply, making for lengthy reply messages
that contain substantial portions that are identical to mail already
saved at the client or target unit. While this has come to be expected
1o in email replies, it is also quite costly in time and tariff charges in
bandwidth limited systems like most wireless communication
systems.
Starting from a client perspective, the process of FIG. 9
commences with a client formulating a reply to a received mail
z5 message, much as he or she would for any typical email application
(step 902). However, when the user executes the reply, e.g., by
clicking on a send button, the client controller (201 of FIG. 2)
optimizes the reply message by calculating a delta or difference,
using any appropriate delta routine, between the reply message and
20 the preceding message. This delta is then formed into an optimized
reply along with a message/data unit identifier for the preceding
message/data unit (preferably the mail serial number, although any
retrievable identifier of the preceding message may be used, suck as
header information, or even a CRC (cyclic redundancy check) value)
(step 904). To ensure that only the shortest message is being sent,
the controller additionally compares the reply message with the
optimized reply to determine which is optimum for transmission
(step 906). This determination may be made based on a comparison
of the message sizes, compressed and formatted message sizes, or
any other convenient means for estimating - which version of the reply
will require the least bandwidth or transport cost. Thus, for
example, a normal reply message to a very short message may be
selected for transmission where the overhead of the delta and
CA 02365520 2002-O1-09
21
message identifier make the optimized reply bigger than the normal
reply message would be. However, in most instances it is
anticipated that the optimized reply will be smaller than a normal
reply message, providing significant savings to the client in time and
costs.
When the optimized reply is received at the QM of the
communication server, a determination is made on whether to
reconstruct the normal reply message (i.e., form a replica reply) or to
forward the optimized reply, based on known parameters (if any) of
l0 the target communication unitlclient. Thus, for example, where both
the originating and target clients are active and served by the same
communication server and thus are known to have optimized reply
capabilities, and the target client was an addressee or originator of
the preceding message identified by the message identifier of the
optimized reply, a reconstructed reply may ,not be required. Rather,
since the preceding message would either be in the inbox or outbox of
the target unit, the target unit can reconstruct the reply message
from the identified mail in its mailbox and the delta. This
advantageously allows bandwidth to be minimized for both the
sending and target clients. Further, if perchance the target unit has
already deleted the identified preceding message, the controller of
the target unit could, rather than acknowledge receipt, send a
request for the normal reply message, which the communication
server would reconstruct as described next.
In cases where the target unit is not an active client with the
communication server, the QM (or other appropriate entity of the
controller) functions to reconstruct the reply message from the
optimized reply. Because the communication server preferably does
not retain a copy of client mail or data located on other hosts (suck
3o remote stores typically adding complexity and cost, while being
unnecessary in view of the virtual session established via the
communication server), it would use the identifier to retrieve the
preceding message from the host (e.g., send a query object or
' ~ CA 02365520 2002-O1-09
22
message to the appropriate post office) (steps 908-912). This can be
implemented by requesting the preceding message from the client
inbox, or from the originating unit's outbox (or even the target unit's
inbox, if it is a cc: on the preceding message). Because the serial
number is a unique number widely used in email applications, this is
the preferable message identifier for email systems. However,
where this unique number is unavailable other identifiers may be
used, including author, date andlor subject matches. Further, for
some messages it may even be advantageous to use other relatively
unique values, such as CRC or other values, by themselves or together
with other identifiers. It is relatively unimportant for purposes of
the invention what the identifier is, as long as it is useful within the
accuracy demanded by the system design for retrieving the correct
preceding message:
Once the preceding message has been received by the
communication server, it uses a counterpart delta routine to that of
the client to reconstruct a replica of the reply message from the
delta of the optimized reply and the retrieved copy of the preceding
message. Once reconstructed, the reply message is forwarded to the
target unit(s), as well as to the outbox or sent mail folder of the
client's post office box (steps 914-916). While some additional
processing and network traffic is required between the
communication server and host, this is relatively inexpensive
compared to the savings achieved by using an optimized reply over
the tariffed network between the communication server and client.
While the preceding approach can be implemented without
resort to a message index, it can be further optimized by use of
indices at the communication server and client. In this case, a full
index of each active client's mailbox (or other application file(s)) is
maintained at both the client and the communication server. This
index could advantageously be one of the S&S indices 213 and 228 of
FIG. 2 designed to include all mail (although perhaps with less
identifying information for received mail than, for filter-restricted
CA 02365520 2002-O1-09
23
mail, depending on factors such as the memory available and the
amount of identifying information desirable). When an optimized
reply is received at the communication server, a search of the
appropriate client index (e.g., first the target unit, if also an active
client, otherwise the client's or originating unit's indices) for the
message identifier of the preceding message, indicating whether or
not the preceding message has been deleted. When the preceding
message's identifier is present, the process continues. as noted
above, in other words by sending the optimized reply to the target
unit, or reconstructing the reply message and forwarding it to the
target unit.
Replies being sent to the client can similarly use an optimized
reply to minimize messaging sizes. Thus, for example, where a reply
is received by the communication server which has the client as an
addressee, the communication server is capable of generating a delta
between the reply message and a preceding message known to be
stored in a mail database (e.g., memory 214 of FIG. 2) of the client.
The preceding message is most easily identified if an additional
identifier is included with the reply for ease of searching in the
2o client's index. However; where such is not included, identifier's can
be extracted from the text (e.g., author, date, recipient, subject) for
comparison matching. Alternatively, a comparison of the text of the
reply message can be used in determining the preceding message. For
example, a series of preceding messages could be retrieved for
textual comparison; or alternatively an identifying value for all or
selected (e.g., sent) mail can be maintained (e.g., by calculating the
text CRC value and storing it in the index), and a check of selected
portions (e.g., all portions below insertions identifying preceding
messages in the text) of the reply message text can then be
3o performed. The latest or largest matching preceding message is the
selected (which could be either a message sent to, or sent from, the
client), so as to minimize the delta, and the delta calculated between
the preceding message and the reply message. An optimized reply is
then formed including the delta and preceding message identifier
CA 02365520 2002-O1-09
24
recognizable by the client. This optimized reply is then forwarded,
and reconstructed at the client into the reply message. In other
words, the client retrieves from memory the message corresponding
to the message identifier, and forms a replica of the ~ reply message
from the delta and message. Once acknowledged, both client and
communication server indices are appropriately updated to reflect
the mail transfer (steps 918-930).
This embodiment thus provides an efficient process for
sending reply data between a client and the communication server,
without requiring the costly transfer of earlier transmitted portions
of the reply data.
In a final embodiment, a rate governor is provided so as to
assist clients in maintaining their messaging and expenses within
desired limits. Turning to FIG. 10, with reference also to FIG. 2, one
embodiment of such a rate governor is illustrated. This rate
governor operates to track the approximate time and/or expense for
client use, which can be as simple as timing a circuit-switched
connection, or where packet data is being sent, timing (or estimating
based on size) the time and/or cost of transmitting the packet over
~ the tariffed network(s). In estimating the transmission value (e.g.,
cost), a rate governor could better estimate actual costs by taking
into account known pricing factors established by each network
service provider (e.g., rates by time of day, by grade/ quality of
service (QoS) for packets, by size or bandwidth desired, etc.). These
values would be maintained for application by the rate governor (234
of FIG. 2) as each data unit is received to determine an estimated
transmission value.
In the illustrated case of an email application, upon receiving a
client-generated message the QM (or other appropriate controller
3o entity of the communication server) passes the pertinent packet
information or message parameter (e.g., the packet size from the
header) to the rate governor, which in this case operates as a packet
rate governor (or PRG). The PRG determines from the client object
., ' CA 02365520 2002-O1-09
(or profile store) the amount .of use time and/or charge still
available (or alternatively, the .amount already used, and limits
allowed), and compares the use time remaining (e.g., a previously
authorized or allocated transmission value) against the value for the
5 message parameter (step 954).
Preferably several limits are established, including one or
more alert thresholds. These alert thresholds would serve to warn
the client each time a certain threshold is passed in amounts of
time/charge used or remaining, permitting the client to limit use as
10 needed to stay within budget, or to seek a higher limit in advance of
the point at which the use limit is reached. This use or transmission
limit serves as the budgeted limit for data transfers. Unless a user
is privileged, once the use limit is reached further
communications/data transfers are restricted. tn the simplest form,
15 such transfers are restricted by alerting the client that the use limit
has been reached, terminating the current session and preventing
further sessions until additional use limit time/charge is authorized.
Alternatively, certain messaging could still be permitted (based, e.g.,
on any filterable criteria--e.g., permitting messages to the
20 administrator but not a further communication unit), but with
reminders that routine messages will not be forwarded. This would
advantageously allow critical messages, messages to an
administrator (e.g., requesting additional authorization), etc., to still
be transferred, although it does not prevent a user from running up
25 excess charges for messaging to the communication server. A PRG
may thus also be advantageously used in the client (e.g., PRG 209 of
FIG. 2), signaled by the PRG of the communication server to
automatically set certain prestage filters to restrict all but certain
message transfers until a new use limit is, provided. If a user were
to bypass this client PRG and continue improper messaging, all
further sessions could be terminated by the communication server
with notification to the administrator and client.
CA 02365520 2002-O1-09
26
If the user is privileged, data transfers would still continue
despite the user limit having been exceeded. However, an alert would
still preferably be sent to both the client and administrator,
allowing the administrator to verify the privilege and reset the use
limit if desirable, and the client to still be aware it has passed a
targeted use amount (steps 956-968 and 980-984). In any event,
after each data transfer the client object or store is updated to
reflect the new estimated transaction total (e.g., time remaining,
total expense, etc.) (step 958).
1o As mentioned above, if a user is not privileged it is preferable
to allow the client an additional data transfer to an administrator
requesting additional allocation of time/ charges. This request
would be forwarded by the communication server to the
administrator host, where it would be processed for approval. If
approved, the administrator would notify the communication server
to adjust the use limit by a specified amount. Alternatively, if there
is no system administrator, but charges or debits are handled through
a communication server service provider, the client may send any .
appropriate authorization for additional chargeldebit to the
2o communication server (e.g., by sending an encrypted account number
and identifying information like a PIN (personal identification
number). Once the charge or debit is processed and approved to the
service provider's satisfaction, the amount of charge or debit would
be used to adjust the use limit. A notification would also be
forwarded to the client of the new use limit, with the client PRG
being updated accordingly (steps 970-978).
In addition to updating the use limit in response to a user or
administrator request, the rate governor can also be advantageously
set to automatically update the use limits upon the occurrence of a
3o predetermined update event. Thus, for example, where billing and
budgeting is done on a monthly cycle, and the administrator has set
rate governor preferences so as to automatically reset the use limit
on the first day of the next billing cycle, the communication server
CA 02365520 2002-O1-09
c
27
will automatically reset the client use limit at the specified time
and in the specified amount (step 992).
Moreover, in order to achieve an even more accurate billing
control, the communication server could be coupled with the tariffed
network service providers) so as to receive periodic charge
statements for client data traffic, as well as updates for tariff
rates, etc. In order to take advantage of these statements, a billing
index would be maintained for each client estimating use and charges
for each data transfer. Upon receiving the periodic charge statement
l0 (e.g., forwarded once a day during an administrative window) the
estimated use entries are replaced by the actual use and charges
from the statement, and the client profile (and object, if active) is
updated to reflect a corrected use limit, etc. The administrator is
notified, and the client is notified upon the next transaction, of the
updated amount. If desired, the client or administrator can request a
download of the current billing index showing the most recent .
estimated and actual charges (steps 986-990).
Finally, one should appreciate that the above process is equally
applicable to groups as well as to individual clients. Thus, the PRG
2o can advantageously be used to set use limits for groups and
supergroups of .users, as well as for individual clients as described
above. Thus, where one of the applications being used is groupware,
as opposed to the email example described above, different groups
can be assigned group use limits for groupware data transfers
(while retaining individual use limits for separate email or data
transfers, etc.): To avoid one or two users exhausting the group's
authorized limit, individual use limits can still be set for each
client, although with more flexibility, e.g., to draw on unused group
time before requiring additional allocation from an administrator, to
3o permit another user of the group to yield a portion of its individual
use limit, etc. As should be apparent, many variations exist on how
the rate governor is structured, depending on the applications being
used, clients and groups operating, the interactivity with service
CA 02365520 2002-O1-09
28
providers, complexity or simplicity desired, and many other related
and unrelated factors.
One skilled in the art will appreciate that there are many
variations that are possible for the present invention, only a limited
number of which have been described in detail above. Thus, for
example, while the embodiments above describe application to
clients communicating in certain systems, one should appreciate that
it has application to any communication system, wired or wireless,
client-server, distributed or other networks, etc., in which the user
is remote from a host. It can also be used with almost any
application program or groups of programs (e.g., transferring
database, wordprocessing, graphics, voice etc. files, executing
programs and control messages, etc.), not just email or groupware.
Moreover, white processor 206, controller 229, timers 205 and 224,
data stores 211 and 225, and other circuits, are described in terms
of specific logicallfunctional/circuitry relationships, one skilled in
the art will appreciate that such may be implemented in a variety of
ways, preferably by appropriately configured and programmed
processors, ASICs (application specific integrated circuits), and
2o DSPs (digital signal processors), but also by hardware components,
some combination thereof, or even a distributed architecture with
individual elements physically separated but cooperating to achieve
the same functionality. Thus, it should be understood that the
invention is not limited by the foregoing description of preferred
embodiments, but embraces all such alterations, modifications, and
variations in accordance with the spirit and scope of the appended
claims.
