1. CS1: Wireless Communication and Mobile Programming
Wireless Technologies:
Short Message Service (SMS)
Dr. Khaled Mahmud
Laurentian University International Global Experience Program
Summer–2016

2. Agenda Short Message Service (SMS) SMS Architecture
Types of Messages
Value Added Services (VAS) using SMS
Architecture
Short Message Peer to Peer (SMPP)
Using SMS as bearer
(c) Khaled Mahmud

3. Reference
Chapter 6 [TEL]
Web references
(c) Khaled Mahmud

4. Overlay of Mobile Data in GSM
The data service make use of the followings of a GSM system
Spectrum allocated to other service
MAC frames
Air interface
Short Message Service (SMS)
Make use of free time slots within the signaling channels
General Packet Radio Service (GPRS)
Make use of free time slots within the TCH (Traffic channel of GSM)
Amount of new infrastructure is reduced to bare minimum
Most of the extra components required are implemented in software
Cheap
Easy to deploy
(c) Khaled Mahmud

5. Short Message Service (SMS)
Developed as part of GSM phase 2 specs
Alphanumeric messages up to 160 characters gets mapped into 140 bytes
Utilizes the logical channels of the GSM system intelligently
Requires an additional SMS Center (SMSC)
Maintenance and transmission
Sorting and routing
(c) Khaled Mahmud

6. Cell Broadcast SMS
The message is transmitted to all MSs that are active in a cell and subscribes to the service
Unconfirmed one way message used for
Weather forecasts
Stock quotes etc.
A cell broadcast entity and a cell broadcast center broadcast to multiple BSCs for delivery
The broadcast contains data and identities of the MSs that are to receive this data
Employs the Broadcast Channel for this
(c) Khaled Mahmud

7. Point to Point (PTP) SMS
An MS can send message to another MS
If the MS is in idle mode
MS has to establish a connection to the network similar to a normal call set up (for MS originated SMS) or
The MS has to be paged and a connection needs to be set up between the network in a manner similar to a normal call set up
(c) Khaled Mahmud

8. Mobile Originated SMS
SM (short message) originating from the MS reaches MSC
A dedicated function in the MSC called SMS interworking MSC (SMS-IWMSC) forwards it to the SMSC using the global SMS ID
SMS-IWMSC
MSC
VLR
SMSC
(c) Khaled Mahmud

9. Mobile Terminated SMS
SM is forwarded from the SMSC to the SMS gateway MSC (SMS-GMSC) function of the MSC
The routing information is obtained from the HLR
The MSC/VLR pages the MS
VLR
MSC
SMSC
SMS-GMSC
HLR
(c) Khaled Mahmud

10. Overall SMS Architecture
SMSC (SC)
HLR
SMS-GMSC
SMS-IWMSC
VLR
MSC
MS1
MS2
Receiver's home network
Sender's home network
Serving network
SM MO
SM MT 1 3 2 4 5 7 12 8 9 10 11
(c) Khaled Mahmud

11. Misc. Information on SMS
SM is transmitted through the GSM infrastructure using SS-7
SM can have
Specified priority level
Future delivery time
Acknowledgement of message receipt
Failure can occur if there is change of state of the MS when the SM is in transit
(c) Khaled Mahmud

12. Value Added Service (VAS)
Supplementary services, but adds value to the total service offering
Stimulates incremental demand for the core service
Creates revenue generation potential
Sometimes can be stand-alone
Can a be an add-on to the basic service, usually sold at a premium price
(c) Khaled Mahmud

13. VAS Through SMS SMS can be bearer for VAS SMS may carry
Static information: Less update necessary
e.g. restaurant guide
Dynamic information: Daily or more frequent update necessary
e.g. daily horoscope
Real-time information: Almost real-time update necessary
e.g. Live cricket update
(c) Khaled Mahmud

14. VAS over SMS Examples News/stock quote service Session-based chat
Twitter
through SMS
Health-care service
Micro-payment service
(c) Khaled Mahmud

15. Architecture for VAS over SMS
MSC
BSC
BTS
SMSC
SME/
SMS
gateway
Internet
Content
Server
Data
store
Enterprise content
Mass market content
Content update
SME: Short Message Entity
(c) Khaled Mahmud

16. Short Message Entity (SME)
Makes connection between enterprise origin server and SMSC
SMS gateway for the enterprise
Also called External SME or ESME
Interface between SMSC and SME or SME and enterprise server is not defined in GMS
Between SMSC and SME or ESME:
SMPP (short message peer to peer) is used mostly
Between SME and content server:
Usually HTTP/TCP based protocol is used (e.g. SOAP)
(c) Khaled Mahmud

17. Communication Between SMSC and SME
ESMEs
SMSC
SMPP
WAP Proxy server
Mobile NW
SMPP
VMS
SMPP
Paging
(c) Khaled Mahmud

18. Lookout for SMS Scam :Normal SMS Operation
(c) Khaled Mahmud

19. Lookout for SMS Scam :Fraud Operation
(c) Khaled Mahmud