Mobile Technologies

• Introduction

• Basics of GSM

• Value Added Services

• SMS

• Short Codes

• Asterisk *

• LBS

Basic Unit of GSM Networks

GSM Components

• MSC – Mobile Switching Center• BSC – Base Station Controller• BTS – Base Transceiver Station• VLR – Visitor Location Register• HLR – Home Location Register• LMU – Location measurement Unit• SMLC – Serving mobile location center• GMLC – Gateway mobile location center

GSM Architecture

Base Station

VLRMSC

VLR MSC

HLR

land link

land link

Radio link

MSC – Mobile Switching Center

• Deliver Calls to Subscribers

• Uses VLR data to route calls

• Deliver SMS to handset from the SMSC

• Handles BSC to BSC Handovers

• Collect billing information

BSC – Base Station Controller

• Controls Many BTSs

• Allocates radio channels

• Handles BTS to BTS handovers

Basic Unit of GSM Networks

BTS – Base Transceiver Station

• Radio Base Station

• Handles the Wireless communication

• Transceiver

• Power Amplifier

• Antenna

BTS

BTS Sectors

Cell Management

HLR – Home Location Register

• Stores details of each SIM

• GSM services accessible to a subscriber

• Current roaming area

• Retrieves information from BSC

• Updates VLR

• Acts as the middle man for SMS and calls

VLR – Visitor Location Register

• Local cache for HLR

• Used to setup the call quickly

• Directly connected to the MSC

• Stores the MCC, MNC and cell ID

Call Establishment

GSM Network Elements

SS7

SMS – Different Types

• Point to Point

• Broadcast

SMS – Different Types

• User Specific

• ME Specific

• SIM Specific

SMSC

Mobile Originated SMS

Mobile Terminated SMS

SMS

Short Codes

• Pull Service

• Premium Billing

• Connects all mobile users

• Short Code Nation

Short Code Demo

Send GO JACOB to 3636

www.go3636.com

Short Code Architecture

Asterisk *

• Software PBX

• Open Source

• Written in C

• APIs are available for integration

• Supports many industry standards

What is a PBX

Local TelcoPBX

Local Telco

Asterisk at Work

Linux PC - AsteriskLocal Telco

Telephone Lines

IP Phone

IP Phone

Soft Phone

Desktop PC

Analog Phones

Intern

et

Soft Phone

Positioning Technologies

• Handset Based

• Network Based

• Hybrid

GPS

• Free To Use

• 24 Satellites in Orbit

• Maintained by US Defense

• NAVSTAR GPS

• NAVigation Satellite Timing And Ranging

• Minimum 3 Satellites needed for Positioning

GPS Satellites in Orbit

School Mathematics

Time Difference of Arrival

A-GPS

• GPS + Network

• Assistance Server

• Useful Where 3 Satellites are not in Range

• Speedy calculations

• Future Mobiles will have GPS Receivers

LMU – Location Measurement Unit

• Monitors Signals from BTS

• Monitors Satellite GPS Data

SMLC – Serving Mobile Location Center

• Coordinates the location calculation process

• Does calculation based on known values

• Converts the location information into Latitude and Longitude

GMLC – Gateway Mobile Location Center

• Provides External Access to Location Data

• Queries the SMLC to get the location information

• Authorization

• Billing

GSM Architecture with LBS

Location Based Services.

• Emergency services (911, 100, 101 etc)

• Traffic / Weather alerts

• Location sensitive advertising

• Destination maps