1. Mobile System SMS - 160 bytes that saved an industry Johan Montelius jm@sics.se

2. Overview Background –History of SMS, functionality, usage … Infrastructure –SMSC, SMPP, GSM 03.40 … Message format –160 characters, Smart-messaging, EMS …

3. In short two-way –terminals can both send and receive stor-and-forward –delivered when terminal is activated short message –140 bytes or 160 7-bit characters available –mainly GSM systems but also in other cellular systems

4. History Specified in GSM phase 1 standard First public service in 1994 Roaming –Slowly introduced in 1999 Market takes off in 1999 –1 billion messages/month in Apr 1999 –3 billion messages/month in Dec 1999

5. Market growth

6. Telia in Norway and Sweden 2001 Norway: 900M messages/ 1 M subs Sweden: 400M messages/ 3,2 M subs Norway: 13% of turnover Sweden: 4% of turnover

7. Usage Operators report an average of 10-30 user originated messages per month. Traffic: –voice message notification –P2P messaging –ring tones / logos –sports scores –other information services

8. Premium SMS Same request short- number (1985) regardless of operator. Sender of request is charged 10 NOK. Request sent as SMS message

9. Location based services Request sent as SMS message Operator dependant service

10. Will SMS be replaced?

11. Infrastructure MT –SMS capable terminal SMSC –Short message service centre Mobile network –Network to deliver the SMS

12. SMSC – the heart of SMS SMSC IWMSC/GMSC GSM Network MT MSC

13. SMSC Interface MSC SM-TP Short message transport protocol GSM 03:40 GSM 04:11 GSM 09:02 HLR SMSC Fixed network Not standardized by ETSI

14. the SMSC Vendors –CMG, Comverse, Logica, Sema Group … Servers –Reliable, distributed –2500 messages/s –Integrated billing support

15. Everyone wants a standard Logica Fixed network TCP/IP X.25 SMPP www.smsforum.net UCP CIMD OIS Sema CMG Nokia

16. Intermediator

17. SMS format Specified in GSM 03:40 and 09:11 140 bytes or 160 7-bit characters Three types of messages: –User: normal text messages –Mobile: OTA configuring –SIM: operator specific applications

18. Extensions to SMS Nokia: Smart messaging –OTA provisioning –ring tones, logos EMS Enhanced Messaging Service –3GPP –Ericsson, Siemens, Alcatel, Motorola –ring tones, sound, logos, images, animations, text style …

19. EMS standard 7-bit characters EMS header - Content -Formating information, pre-defined or user supplied content. - Pointers -Where in the text flow?

20. Do it yourself SMS interface -Modem signaling using standard GSM phone