1. MIT D-Lab ICT4D
Lab 1: SMS Services

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!

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

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)
Subscription Service
User can subscribe to alerts
e.g., FINDJOB SUBS DRIVER

5. Mobile “Value-Added Services (VAS)” Architecture
3rd party app providers (aka content providers, “CPs”)
small 3rd party CPs
Users
direct connection
MNO
aggregator
SMSC
VAS gateway
in-house apps
private “service” via GSM modem or phone

6. Writing SMS Apps: Three Options
direct to Mobile Network Operator
via Aggregator
using GSM modem or phone

7. Tools Open Source Kannel SMSLib Gnokii, etc. Commercial Aggregators
e.g., Clickatell
Libraries for Using Private Lines
e.g., NowSMS, WinSMS, etc.

8. Programming Options Protocols Languages
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

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

10. Lab Examples

11. Writing an App (Easy!) IMPLEMENT THIS
public interface SMSApplication {
public SMSMessage onSMSMessageReceived(SMSMessage incomingMsg);
public void setSMSSender(SMSSender sender); }
public interface SMSSender {
public boolean sendSMSMessage(SMSMessage outgoingMsg);
IMPLEMENT THIS

12. How to connect your app Via Java Alternative: PHP
via GSM modem adapter
via SMSLib
via HTTP GET adapter
connecting from Kannel or other gateways
(via adapter)
Alternative: PHP

13. Other Issues
Databases
Web Interface

14. References See ict4dlab.org for more info and links
This is under development, so visit often for up-to-date info

15. Application Design Tips and Tricks

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

17. Caveats: Security
Watch for “SQL Injection” attacks!

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”