CA2568815A1

CA2568815A1 - Adjustable download rate for a portable electronic device

Info

Publication number: CA2568815A1
Application number: CA002568815A
Authority: CA
Inventors: Dan Dumitru; Rakesh Arora; Eshwar Stalin
Original assignee: Research in Motion Ltd; Arizan Corp
Current assignee: BlackBerry Ltd
Priority date: 2006-11-23
Filing date: 2006-11-23
Publication date: 2008-05-23
Anticipated expiration: 2026-11-23
Also published as: CA2568815C

Abstract

A method for downloading data from a server to a portable electronic device operating on a wireless network includes determining a network speed of the wireless network, setting a chunk size based on the network speed, sending a request to the server including the chunk size and receiving data from the server in chunks having the chunk size.</SD OAB>

Description

ADJUSTABLE DOWNLOAD RATE FOR A PORTABLE ELECTRONIC DEVICE
FIELD

[0001] The present disclosure relates to portable electronic devices operating on wireless networks, in particular, to an adjustable download rate for data transferred to portable electronic devices.

BACKGROUND

[0002] On a portable electronic device, the performance of applications that use wireless networks to transfer data is highly dependent on the throughput of the wireless network. The network speeds of older wireless network technologies such as GPRS (General Packet Radio Service), for example, vary significantly from those of more modern wireless networks such as EDGE (Enhanced Data GSM (Global Systems for Mobile) Environment), UMTS
(Universal Mobile Telecommunications System) and HSDPA (High Speed Downlink Packet Service), for example.

[0003] Typically, the chunk size is a default value that is determined for a specific device type. If the default chunk size is large, devices operating on slower networks will perform poorly. If the default chunk size is small, devices operating on high speed networks will not fully utilize the capability of the network. Therefore, it is desirable to select a chunk size that is suited to the wireless network in order to optimize data transfer.

SUMMARY

[0004] In one aspect there is provided a method for downloading data from a server to a portable electronic device, the method including: determining a network speed of a wireless network on which the portable electronic device is operating, setting a chunk size, the chunk size being determined based on the network speed, sending a request to the server including the chunk size and receiving the data from the server in chunks having the chunk size.

[0005] In another aspect there is provided a method for requesting and viewing an attachment of an email message in an attachment viewer of a portable electronic device, the method including: sending a request from the portable electronic device to an attachment server to view the attachment in the attachment viewer, the request including a chunk size for receiving the attachment, building a graph structure within the attachment server representing a map of the attachment and encapsulating the graph structure in an attachment viewer readable format and sending the attachment in the attachment viewer readable format from the attachment server to the portable electronic device, the attachment being received in chunks having the chunk size; wherein the chunk size is determined based on a speed of a wireless network on which the portable electronic device is operating.

[0006] In another aspect there is provided a portable electronic device operating on a wireless network, the portable electronic device including: an attachment viewer stored on the portable electronic device, the attachment viewer for requesting to view the attachment and providing a chunk size for receiving the attachment and an attachment server in communication with the attachment viewer, the attachment server for building a graph structure representing a map of the attachment and sending the attachment to the attachment viewer;
wherein the chunk size is determined based on a speed of the wireless network.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The embodiments will be better understood with reference to the following Figures in which like numerals denote like parts and in which:

[0008] Figure 1 is a schematic diagram of a wireless communication system;

[0009] Figure 2 is a block diagram of components of a portable electronic device according to an embodiment; and [0010] Figure 3 is a flowchart showing device-side operation of a method for downloading data to an Attachment Viewer of the portable electronic device of Figure 2;
and [0011] Figure 4 is a flowchart showing server-side operation of a method for downloading data to an Attachment Viewer of the portable electronic device of Figure 2.

DETAILED DESCRIPTION

[0012] Referring now to Figure 1, a communication system 10 for a portable electronic device 12 is generally shown. The portable electronic device 12 is operable to effect communications over a radio communications channel and communicates with a base station (not shown) while located within a coverage area that is defined by the base station. The base station is part of a wireless network that is in communication with the Internet 14. Data is delivered to the portable electronic device 12 via wireless transmission from the base station.
Similarly, data is sent from the portable electronic device 12 via wireless transmission to the base station.

[0013] It will be appreciated that the portable electronic device 12 is movable within the coverage area and can be moved to coverage areas defined by other base stations. Further, as will be understood by one of ordinary skill in the art, wireless networks include GSM/GPRS, CDPD, TDMA, iDEN, Mobitex, DataTAC networks, EDGE, EVDO or UMTS and broadband networks such as Bluetooth and variants of 802.11.

[0014] A server 18 handles wireless client requests from the portable electronic device 12.
A firewall, or proxy server, 16, is provided between the server 18 and the Internet 14. The server 18 further operates as an Attachment Server, which communicates with an email ciient and an Attachment Viewer of the portable electronic device 12 to allow a user to view attachments that are received in email messages. While only one server 18 is shown for illustration purposes, a person skilled in the art will understand that the Attachment Server may alternatively be a separate server.

[0015] Referring now to Figure 2, a block diagram of certain components within the portable electronic device 12 is shown. In the present embodiment, the portable electronic device 12 is based on the computing environment and functionality of a wireiess personal digital assistant (PDA). It will be understood, however, that the portable electronic device 12 is not limited to wireless personal digital assistants. Other portable electronic devices are possible, such as smart telephones, and laptop computers.

[0016] The portable electronic device 12 is based on a microcomputer including a processor 20 connected to a read-only-memory (ROM) 22 that contains a plurality of applications executable by the processor 20 that enables each portable electronic device 12 to perform certain functions including, for example, PIN message functions, SMS message functions and cellular telephone functions. The processor 20 is also connected to a random access memory unit (RAM) 24 and a persistent storage device 26 which are responsible for various non-volatile storage functions of the portable electronic device 12. The processor 20 receives input from various input devices including a keypad 28. The processor 20 outputs to various output devices including an LCD display 30. A microphone 32 and phone speaker 34 are connected to the processor 20 for cellular telephone functions. The processor 20 is also connected to a modem and radio device 36. The modem and radio device 36 is used to connect to wireless networks and transmit and receive voice and data communications through an antenna 38. A
content store 40, which is generally a file storage system for the portable electronic device 12, is also provided.

[0017] Request/view functionality for an attachment of an email message received by the portable electronic device 12 is provided by the Attachment Viewer and the Attachment Server.
The Attachment Viewer, which is an application that is run by the processor 20 of the portable electronic device 12, displays images that correspond to attachments.

[0018] Referring to Figure 3, device-side operation of a method for requesting and viewing attachments on the portable electronic device 12 is generally shown. In order to view an attachment that is received in an email message, a user first opens the attachment in order to launch the Attachment Viewer. The user then selects "Full Content" from an Attachment Viewer menu, as indicated at step 42, in order to view the complete attachment.
Before the "Full Content" request is relayed to the Attachment Server 18, the Attachment Viewer determines the type of network on which the portable electronic device 12 is currently operating, as indicated at step 44.

[0019] Wireless networks are categorized into two groups by the portable electronic device 12: fast networks and slow networks. Fast networks include: EDGE (Enhanced Data GSM
Environment), EVDO (Evolution-Data Optimized), HSDPA (High Speed Downlink Packet Service) and UMTS (Universal Mobile Telecommunications System) Networks, for example.
Slow Networks include: GPRS (General Packet Radio Service), CDPD (Cellular Digital Packet Data), TDMA (Time Division Multiple Access), iDEN, Mobitex, and DataTAC, for example. Each category of network speed has a corresponding default chunk size for downloading data to the portable electronic device 12 associated therewith. If the network is a slow network, the Attachment Viewer sets the chunk size for receiving streamed data to 16 Kilobytes (K), as indicated at step 46. If the network is a fast network, the Attachment Viewer sets the chunk size to 32K, as indicated at step 48.

[0020] Device processor speed and device memory also contribute to the determination of network category. Since greater processing power is required to process and display larger data chunks, a device having limited processing power will be placed in the slow network category regardless of the speed of the actual network on which the device is operating.

[0021] Once the chunk size for downloading the attachment has been determined, the Attachment Viewer of the portable electronic device 12 sends an XML
(Extensible Mark-Up Language) request to the Attachment Server 18, as indicated at step 50. In the request, the chunk size is indicated by <CS> or <XCS> tags. For example the string:
"<CS>32000<CS>"
indicates that the chunk size being requested by the Attachment Viewer is 32K.
The request is then processed by the Attachment Server 18 and the attachment is downloaded in chunks having the specified chunk size to the Attachment Viewer, as indicated at step 52. The downloaded attachment is then viewable by the user in the Attachment Viewer.

[0022] In order to preserve the integrity of the request even if a device 12 switches from a slower network to a faster network or vice versa, the original chunk size that is requested will be preserved to ensure no re-pagination is required. Subsequent attachment download requests, however, will reflect the different network type [0023] Referring to Figure 4, server-side operation of the method for requesting and viewing attachments on the portable electronic device 12 is generally shown. At step 54, which corresponds to step 50 of Figure 3, the Attachment Server 18 receives a request from the Attachment Viewer to view an attachment that was received with an email message. Upon receipt of this request, the Attachment Server 18 first determines if the attachment has a unique Document Object Model (DOM) id, as indicated at step 56. If so, this indicates that the attachment has been previously viewed and may be retrieved from the Attachment Server 18. If the DOM was recently viewed, it is retrieved from server cache, alternatively, the DOM is retrieved from a document database on the Attachment Server 18. The Attachment Server 18 then transerpts the DOM and encapsulates the DOM into Universal Content Stream (UCS) data, which is a format that is readable by the Attachment Viewer, and sends the UCS
data to the portable electronic device 12, as indicated in step 64. The transcerption process generally includes preparing the DOM for transmission to the portable electronic device 12 and is described in United States Patent Application No. 200210161796, which is herein incorporated by reference.

[0024] If the attachment has not been previously viewed, the Attachment Server 18 builds a DOM that represents the attachment by parsing the attachment document (step 58). In this manner, a graph structure is built within the Attachment Server representing a map of the original attachment file. The DOM contains textual content, font, style and formatting attributes as well as layout attributes, such as page/slide size, positioning information (ie. x, y and z coordinates on the page), embedded graphics and tables, for example. DOM
structure is well known and is disclosed in United States Patent Application No. 2006/0055693, which is herein incorporated by reference.

[0025] Once the DOM of the attachment is built, the Attachment Server 18 transcerpts the DOM and then encapsulates the DOM in UCS data, as indicated at step 60. The UCS data is then sent to the portable electronic device 12 in chunks, as indicated at step 62. The size of the chunks that are sent corresponds to the size that was provided in the request from the portable electronic device 12 (step 54).

[0026] In operation, when a user selects to view an attachment that was received by the portable electronic device 12 in an email message, a request including a network speed-determined chunk size is sent to the Attachment Server 18. In response to this request, the attachment is downloaded to the portable electronic device 12 in chunks of the requested size.
As the chunks are received by the portable electronic device 12, attachment content is displayed on the display screen 30. By sending data in chunks having a size that is determined based on network speed, the downloading process is optimized and the user is able to view attachments in an efficient manner.

[0027] It will be appreciated by a person skilled in the art that the default chunk sizes are not limited to 16K and 32K. Different default chunk sizes could be set. Further, more than two default chunk sizes could be provided. For example, an even faster network speed category having a default chunk size of 64K may be provided.

[0028] The method for downloading data to a portable electronic device 12 is not limited to downloading attachment data from an Attachment Server. Email body text, for example, may be downloaded from a Mail Server to the portable electronic device 12 in chunks that have a set size that is determined based on the network speed. Similarly, native attachment downloads, which send attachment binary data from an Enterprise Server rather than UCS
data from the Attachment Server, may be performed with a set chunk size that is determined based on the network speed. Native attachment download is useful for portable electronic devices having Microsoft OfficeTM-type programs available. Such programs are capable of displaying doc and .ppt files, for example, using the appropriate Office-type program on the portable electronic device.

[0029] A specific embodiment has been shown and described herein. However, modifications and variations may occur to those skilled in the art. All such modifications and variations are believed to be within the sphere and scope of the present embodiment.

Claims

1. A method for downloading data from a server to a portable electronic device, said method comprising:
determining a network speed of a wireless network on which said portable electronic device is operating;
setting a chunk size, said chunk size being determined based on said network speed;
sending a request to said server including said chunk size; and receiving said data from said server in chunks having said chunk size.

2. A method as claimed in claim 1, wherein said chunk size is set to 16K when said wireless network is a GPRS network.

3. A method as claimed in claim 1, wherein said chunk size is set to 32K when said wireless network is selected from the group consisting of: EDGE, EVDO and UMTS.

4. A method as claimed in claim 1, wherein said data is Universal Content Stream data corresponding to an attachment sent to said portable electronic device in an email message.

5. A method as claimed in claim 1, wherein said data is attachment binary data corresponding to an attachment sent to said portable electronic device in an email message.

6. A method as claimed in claim 4, wherein said request is sent to said server in response to an attachment viewer of said portable electronic device attempting to display said attachment.

7. A method as claimed in claim 6, wherein said server builds a graph structure within said server representing a map of said attachment upon receipt of said request.

8. A method as claimed in claim 7, wherein said graph structure is a Document Object Model.

9. A method as claimed in claim 1, wherein said request includes a < CS > tag.

10. A method for requesting and viewing an attachment of an email message in an attachment viewer of a portable electronic device, said method comprising:
sending a request from said portable electronic device to an attachment server in order to view said attachment in said attachment viewer, said request including a chunk size for receiving said attachment;
building a graph structure within said attachment server representing a map of said attachment and encapsulating said graph structure in an attachment viewer readable format;
and sending said attachment in said attachment viewer readable format from said attachment server to said portable electronic device, said attachment being received in chunks having said chunk size;
wherein said chunk size is determined based on a speed of a wireless network on which said portable electronic device is operating.

11. A method as claimed in claim 10, wherein said chunk size is 16K when said wireless network is a GPRS network.

12. A method as claimed in claim 10, wherein said chunk size is 32K when said wireless network is selected from the group consisting of: EDGE, EVDO, HSDPA and UMTS.

13. A method as claimed in claim 10, wherein said graph structure is a Document Object Model.

14. A method as claimed in claim 13, wherein said attachment viewer readable format is Universal Content Stream format.

15. A portable electronic device operating on a wireless network, said portable electronic device comprising:
an attachment viewer stored on said portable electronic device, said attachment viewer for requesting to view said attachment and providing a chunk size for receiving said attachment;
and an attachment server in communication with said attachment viewer, said attachment server for building a graph structure representing a map of said attachment and sending said attachment to said attachment viewer;
wherein said chunk size is determined based on a speed of said wireless network.

16. A portable electronic device as claimed in claim 15, wherein said chunk size is 16K when said wireless network is a GPRS network.

17. A portable electronic device as claimed in claim 15, wherein said chunk size is 32K when said wireless network is selected from the group consisting of: EDGE, EVDO, HSDPA and UMTS.