lab 1: sms services mit d-lab ict4d. d-lab ict for development lab 1: sms services slide 2 intro to...

Lab 1:SMS Services

MIT D-Lab ICT4D

D-Lab ICT for DevelopmentLab 1: SMS Services

Slide 2

Intro to Lab Sessions

• Goal: Give overview and examples to jump-start you

• Three Sessions– SMS applications– J2ME (on-the-phone apps)– Advanced features (NFC, Location, MMS, etc.)

• But … we can’t teach everything in 3 sessions!– you’re expected to study and follow-up on your own– we’ll just give you simple educational examples – not necessarily the

best or most scalable solutions– you’re welcome to use other tools and techniques not taught in class

• These tools are works in progress -- You’re welcome to help!


Slide 3

Recap: Mobile Phone Capabilities, Apps

• SMS (Text Messaging) –based services– send text commands, receive info– receive alerts and subscriptions

• MMS (Multimedia Messaging) –based services– send and receive multimedia to/from server

• J2ME (Java 2 Micro Edition) applications– programs running on the phone– e.g., games

• Internet/Web services– via WAP (limited) and/or GPRS (dialup-speed connection)– via 3G (broadband speed connection)

• Location-based services– services that make use of location of users

• Micropayment applications– ability to send/transfer cellphone credits via SMS– leads to cash-less, credit-card less, electronic payment mechanisms


Slide 4

Example: SMS Job Finder Service

• Service On-Demand– User texts FINDJOB <JOB> to 123

• e.g., FINDJOB DRIVER

– Service responds (via SMS text message) with …

• Agency: JobsRUs. DRIVER needed as of 2/1/08, Call (987) 654-3210

• Subscription Service– User can subscribe to alerts

• e.g., FINDJOB SUBS DRIVER


Slide 5

MNOMNO

Mobile “Value-Added Services (VAS)” Architecture

Users

SMSC

in-house apps

direct connection

VAS gateway

aggregator

private “service” via GSM modem or phone

3rd party app providers (aka content providers, “CPs”)

small 3rd party CPs


Slide 6

Writing SMS Apps: Three Options

• direct to Mobile Network Operator

• via Aggregator

• using GSM modem or phone


Slide 7

Tools

Open Source

• Kannel

• SMSLib

• Gnokii, etc.

Commercial

• Aggregators– e.g., Clickatell

• Libraries for Using Private Lines

– e.g., NowSMS, WinSMS, etc.


Slide 8

Programming Options

• Protocols– direct via language-specific API– TCP/IP-based protocols

• e.g., CIMD, SMPP, etc.– HTTP-based protocols

• GET, POST, XML-RPC• Languages

– Java, PHP, anything …– Note: probably also need

• backend database• web front-end


Slide 9

Legal Disclaimer

• The information here is for educational purposes only

• We assume your programs will be used for private/personal use only

• If you want to do a commercial or high-volume application, you may have to contact a mobile operator or an aggregator in your target market

Lab Examples


Slide 11

Writing an App (Easy!)

public interface SMSApplication {

public SMSMessage onSMSMessageReceived(SMSMessage incomingMsg);

public void setSMSSender(SMSSender sender);

}

public interface SMSSender {

public boolean sendSMSMessage(SMSMessage outgoingMsg);

}

IMPLEMENT THIS


Slide 12

How to connect your app

• Via Java– via GSM modem adapter

• via SMSLib

– via HTTP GET adapter• connecting from Kannel or other gateways

– (via email adapter)

• Alternative: PHP


Slide 13

Other Issues

• Databases

• Web Interface


Slide 14

References

• See ict4dlab.org for more info and links

• This is under development, so visit often for up-to-date info

Application Design Tips and Tricks


Slide 16

Caveats

• Watch how you keep state

– if you are running app from command-line, state that is not written to disk or persistent database will get lost when you run the app again

– similar issues with web-based solutions


Slide 17

Caveats: Security

• Watch for “SQL Injection” attacks!


Slide 18

General User-Interface Tips

• Make inputs case-insensitive

• Also whitespace insensitive

• Avoid hard-to-type characters

• Try to use keywords in T9 dictionary (or compound words composed of such words)

• Reply-based interfaces– keep per-user state of last transaction

– enables simpler “Reply with …” commands• e.g., “Reply NEXT to continue to get more info”

lab 1: sms services mit d-lab ict4d. d-lab ict for development lab 1: sms services slide 2 intro to...

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