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 VLR MSC VLR MSC HLR 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

Short Code Architecture

Asterisk * Software PBX Open Source Written in C APIs are available for integration Supports many industry standards

What is a PBX

Asterisk at Work

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