IMOBILE: A PROXY-BASED PLATFORM FOR MOBILE SERVICES

IMOBILE: A PROXY-BASED PLATFORM FOR MOBILE SERVICES

Author: Chung-Hwa Herman Rao, Yih-Farn Robin Chen, Di-Fa Chang and Ming-Feng Chen

NETWORK SERVICES RESEARCH CENTER, AT&T LABS

Presented by Pengpeng Lu

OUTLINE

OBJECTIVE

INTRODUCTION

ARCHITECTURE OF IMOBILE

LET ENGINE AND USER/DEVICE PROFILES

SUMMARY

FUTURE WORK

OBJECTIVE

PROVIDE A PERSONAL AGENT ON THE NETWORK THAT ALLOWS MOBILE USERS TO ACCESS ALL SERVICES.

- NO MATTER WHERE THEY ARE.

- NO MATTER WHAT DEVICES.

INTRODUCTION

DIFFERENT DEVICE AND PROTOCOLS DO NOT COMMUNICATE EACH OTHER EASILY: - Palm PDA - Cell Phone - Email Devices - Pocket PCs

MOBILE USERS: - DIFFERENT NEEDS, MOTIVATION AND CAPABILITIES FROM WIRELINE USERS - MULTI-TASKING MODE - VERY TASK-ORIENTED

INTRODUCTION

FIGURE 1. Accessing iMobile Services Through Various Devices and Networks.

ARCHITECTURE OF IMOBILE

FIGURE 2. Architecture of iMobile

FIGURE 3. Architecture of iMobile

DEVLET

A DEVLET PROVIDES A PROTOCOL INTERFACE TO A DEVICE ON A PARTICULAR ACCESS NETWORK.

SUPPORT:

SMS protocol IMAP email protocol

AIM protocolICQ protocol

Telnet protocolWAP protocol HTTP protocol

DEVLET

EACH DEVLET INTERACTS WITH THE LET ENGINE INA STANDARD WAY:

•RECEIVE EACH REQUEST AS A CHARACTER STREAM

• SEND THE CHARACTER STREAM, INTERPREDTED AS AN IMOBILE COMMAND AND ASSOCIATED PARAMETERS TO THE LET ENGINE

• RETURNS RESULTS IN A MIME TYPE ACCEPTABLE BY THE RECEIVING DEVICE (DETERMINED BY THE CORRESPONDING DEVICE PROFILE STORED AT THE LET ENGINE

DEVLET

EACH COMMAND INVOKES AN APPLET THAT CORRESPONDS TO A SERVICE WITH A SET OF SERVICE PARAMETERS

EXAMPLES

TO ACCESS THE STOCK PRICE OF AT&T (T):• quote T

TO FORWARD THE RESULT TO [email protected]• forward mail: [email protected] quote T

INFOLET

RETRIEVE OR WRITE TO AN INFORMATION SPACE USINGAN ACCESS PROTOCOL APPROPRIATE FOR THE INFORMATION SOURCE AVAILABLE

INFORMATION SPACES:

- Stock quote, weather, flight schedule, etc (Access websites) Example: An AIM client of YihFarn talks to an iMoible AIM agent, issued the “flight 008” command to get flight information on the NorthWest airline and received the concise output that includes time and gate information of each leg of the flight

INFOLET

• Mapping from the flight command to the NorthWest airline

• Invoke necessary transcoding services to map to an appropriate format

FIGURE . Accessing Flight Info

Through iMobile.

INFOLET

INFORMATION SPACES (Continued):

- Corporate Database (Accessed through the JDBC and ODBC interfaces) iMobile hosts a JDBC infolet that allows mobile users to access or update enterprise database information (employee data, marketing/sales data, etc) through SQL-like queries.

- Network/Infrastructure Resources (Accessed through the CORBA interfaces) iMobile hosts a CORBA infolet that allows mobile users to request services from CORBA objects.

INFOLET

INFORMATION SPACES (Continued):

- Mobile Control of X10 Home Network Devices iMobile hosts an X10 infolet that controls home network devices connected to its server machine.

- Emailson Mail Servers iMobile supports and IMAP infolet called inbox that can query and view a user’s email account.

APPLET

IMPLEMENT BUSINESS OR APPLICATION LOGIC BY PROCESSING CONTENTS FROM DIFFERENT SOURCES AND RELAYING RESULTS TO VARIOUS DESTINATION DEVICES

An Applet may simply sends a message from one device to another without using any information sources ORHave complex interaction with other infolets.

LET ENGINE

• RECEIVE COMMANDS FROM DEVICES, TRANSLATE THE COMMANDS ACCORDING TO USER ALIASES AND PROFILES, AND THEN FORWARDS THE SERVICE REQUEST TO THE RIGHT APPLET OR INFOLET • INVOKE THE APPROPRIATE TRANSCODING SERVICE TO CONVERT RESULTS RETRUNED FROM INFOLETS OR APPLETS TO A FORMAT APPROPRIATE FOR THE TARGET DEVICE• ALL DEVLETS, INFOLETS, AND APPLETS MUST BE REGISTERED AT THE LET ENGINE FIRST BEFORE COMMUNICATIONS WITH OTHER AGENTS CAN OCCUR

DEVICE PROFILE

EVERY DEVICE MUST REGISTER ITS PROFILE INFORMATION WITH THE LET ENGINE FIRST

DEVICE NAME: protocol:acct_idA DEVICE PROFILE IS A LIST OF ATTRIBUTE-VALUE PAIRS: dev.format.accept: determine what MIME type the device is allowed to accept e.g.: dev.format.accept=text/plain dev.page.size=230

DEVICE PROFILE (CONTINUED)

EVERY DEVLET IS MODELED AS A SPECIAL DEVICE IT REQUIRES MORE INFORMATION IN THE DEVICE PROFILE TO TELL IMOBILE HOW AND WHEN TO ACCESS THIS DEVICE.

e.g.: mail.store.checktime=10000

DEVICE to USER MAPPING

EACH DEVICE HAS TO BE MAPPED TO A REGISTERED IMOBILE USER. REASONS:

- LIMITING ACCESS TO LEGITIMATE IMOBILE USERS ONLY- PERSONALIZE A SERVICE BASED ON THE USER PROFILE

A typical device-to-user map: sms: +886936731826=herman sms: +19087376842=chen mail:[email protected]=difa aim:webciao=chen …

USER PROFILE

A typical iMobile user profile:

name=Robin ChenPassword=xf2gbH3 # command aliasesdefault=$mail.1 sms.cmd.q=quote# my addresses sms.cmd.sn=sitenewssms.1=sms:+19087376842 # address aliases mail.1=mail:[email protected] sms.addr.cc=aim:chrischenmail.2=mail:[email protected]=$mail.1, $mail.2aim.1=aim:webciao

SUMMARY

IMIBILE INTRODUCES THREE ABSTRACTIONS ON TOP OF AN AGNET-BASED PROXY:• DEVLET TO INTERACT WITH VARIOUS ACCESS DEVICES AND PROTOCOLS• INFOLETS TO ACCESS MULTIPLLE INFORMATION SPACES• APPLETS TO IMPLEMENT APPLICATION AND SERVICE LOGICTHE LET ENGINE ARBITRATES THE COMMUNICATIONS AMONG DEVLETS, APPLETS, AND INFOLETS, IT MAINTAINS USER AND DEVICE PROFILES, WHICH ARE USED TO PROVIDE PERSONALIZED SERVICES AND TO PERFORM TRANSCODING BEFORE RETURNING CONTENTS TO RECEIVING DEVICES.

FUTURE WORK

INTEGRATE IMOBILE WITH LOCATION SERVICES TO FURTHER REDUCE THE PARAMETERS (ZIP CODE, LONGITUDE, LATITUDE, ETC.) THAT A MOBILE USER IS REQUIRED TO ENTER TO ACCESS USEFUL INFORMATION

EXPERIMENT WITH VOICE XML TECHNOLOGOES TO PROVIDE A VOICE-BASED DEVLET FOR INFORMATION RETRIEVALS