3. Unstructured Supplementary Services
Data (USSD)
•Short, user-initiated responses (pull)
• –Balance check: Vodacom,tigo: *102#
•USSD supported in all GSM phones.
•New standards support push messages
–Balance Transfer
–M-Pesa
–Instant messaging
•USSD is not SMS!
http://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu
4. Short Message Service (SMS)
•GSM Protocol that allows for exchange of short
messages
•CDMA networks also have SMS protocol
•Each SMS messages is 140 bytes (byte = 8 bits).
–Can encode up to 160 7-bit characters using
default GSM alphabet
http://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu
5. Multimedia Message Service (MMS)
•Extension to SMS that allows message to include
more content:
–Images, videos, and audio
•Use WAP browser to display the message
•Much bigger payload than SMS
•Problems:
–Displaying on different phone (content adaption)
–Access to MMSC from provider
http://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu
6. Short Message Service Center (SMSC)
•GSM network node that delivers SMS messages
•When user sends a messages:
•Forwarded to SMSC
•Stored at SMSC until it can be delivered to recipient
–If msg cannot be delivered, queue for later retry
–Termed Store-and-Forward
•Some SMSCs also provide a "forward and forget" option
where transmission is tried only once
•SMSCs now connected to Internet
–Better quality of service
http://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu
7. SMS Gateways
•Device or service providing SMS transport
–Allowing SMS transport with or without phone
–Allow SMS traffic between business and mobiles
•Direct To Mobile Gateway Appliance
–Mobile phone or USB GSM modem
–Connected to PC, can send/receive messages
–Good for low to medium message volume (this class!)
•Direct To SMSC Gateway
–Gateway connected to SMSC via Internet
–Business has interface to Gateway (usually Internet)
•Gateway then forwards message to SMSC (SMPP)
http://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu
8. Gateway Software for Business
•Installed on Business computer to send/receive
messages
•Can use either Direct-to-Mobile or Direct-to-
SMSC
–Can use multiple at same time!
•Require either:
–Sending device (phone/modem)
–Contract with Operator or Service Provider
http://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu
9. Gateway Software for Business
Examples:
–NowSMS
•Not open-source
–Active Expert
–Kannel
•Linux
•Open source
•Written in C
–smslib
•Windows XP
•Open-source
•Written in Java http://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu
10. Gateway Software for Business
Examples:
-SMS Enabler
–OZEKI
–Active Xperts
http://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu
11. Direct To Mobile Gateway
•Using a phone or GSM Modem as a Windows
modem
–Connecting
–Installing
–Testing
•PC to modem/phone connections
–USB
–Bluetooth
–Infrared
http://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu
12. Service Providers
•Service providers have contracts with operators
–Resell SMS services to you
–Provide APIs to send/receive messages
•HTTP, PHP, Java, etc.
–Can use Gateway software also (smslib)
•Examples:
–Clickatell
•Problems:
–Hard to send messages
http://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu
13. Gateways
•The Service itself is useless. Before starting the Service, you
should define your gateways.
•Gateways refer to the physical devices or services which can
send and/or receive messages.
•SMSLib has the following predefined gateways:
–Serial modem gateway
(classorg.smslib.modem.SerialModemGateway):
–For modems which are connected via serial ports (or
emulated serial ports, like USB etc).
–IP modem gateway
(classorg.smslib.modem.IPModemGateway): for modems
which are connected via IP interfaceshttp://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu
14. Gateways….cont
•Clickatell gateway
(classorg.smslib.http.ClickatellHTTPGateway): for
sending messages viaClickatell.
•BulkSMS gateway
(classorg.smslib.http.BulkSmsHTTPGateway): for
sending messages viaBulkSMS.
•SMPP gateway
(classorg.smslib.smpp.jsmpp.JSMPPGateway): for
sending / receiving messages via the SMPP
protocol.
http://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu
16. SMS is Ubiquitous
•Least-common denominator technology.
–All phone support SMS
–Almost everyone is familiar with SMS
–SMS messages are cheap, free on some
networks
•Reach the most users
•But many constraints
http://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu
17. Types of SMS Applications
•Information Push
•Information Pull
•State Update
•Mobile-Based Systems
•Redirect
•Downloads
http://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu
18. Information Push
•Broadcasting information to a group
–Bible verses, jokes, pickup lines
•Alerts and notifications:
–Ex: weather warnings, coupons, email notification, stock
notification, credit card alerts
•Users can subscribe and unsubscribe
–Via SMS, web portal or email
•Users can pay for service
–Daily / monthly / yearly rate
–Operator agreement
–Reverse SMS billing (charge receiver)
http://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu
19. Information Pull (Query)
•Two way interaction
•User sends a formatted message requesting
information
–Ex: Google search, phone number search,
directions, weather, sport scores, transportation
information
•User subscription or charged per message
–Operator agreement
–Reverse billing
http://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu
20. State Update
•User sends a message to update the state of a system
–Maybe an acknowledgment is returned
•Examples:
–Voting Systems
•Idols East Africa
–Update the state of an Internet site
•Update Facebook/Twitter status, update personal blog, micro-publishing
–Disaster Information:
•Update disaster locations to inform others via SMS
–SMS Forms:
•Predefined format
•Medical Records, Field Surveys, Business Agentshttp://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu
21. Mobile-Based Systems
•User interacts with full system via SMS
–User has continued presence with system
–Database backed
•Protocol of SMS interactions
–“command arguments”
•Menu driven with session support:
–Have to remember the state of the users
interactions
•Examples:
–Independent M-Pesa, IM networks, classified ads
http://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu
22. Downloading
•SMS messages can carry binary data
•SMS can be used as the transport layer for
wireless downloads.
–Ex: ringtones, wallpapers, pictures
http://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu
23. Redirect
•SMS as redirection for phone user
–Can be automatic or require click on link
•Provide a link to WAP site.
–Download ringtone (Cellulant)
–Download image
–Download application
http://mobilekwetu.blogspot.com
twitter: https://twitter.com/mobilekwetu