Transcript Document

CM2502 E-Business
Mobile Services
Mobile Services
Desktop restrictions
Mobile technologies
Bluetooth
WAP
Summary
Desktop restrictions
Internet opens up access to millions of
sites
Browser can walk down virtual high
street
Massive opportunities for opening new
markets through e-business
BUT

Internet access through a fixed device (PC)
Mobility and access
If we can access the internet without
using fixed devices;
information can be provided in many
environments
 information can be more current
 e-business market could be extended
further

How do we mobilise the internet?
Bluetooth
short range, wireless link
allows ad-hoc connections between;
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mobile phone
portable computer
printer
mouse
headset
low power radio, 10-100m range max
2.4 GHz licence-free, frequency-hopping to
avoid interference
Bluetooth
Cellular
(GPRS,
3G)
Packet Data
Infrastructure
Applications: VoIP,
browsing, multimedia
Bluetooth
Addresses connectivity
and convenience issues
for wireless data
Internet
Wireless Application
Protocol
addresses issues higher up the protocol
stack
data links on wireless networks are
lower than wired networks

radio spectrum (bandwidth) limited
internet applications not designed with
wireless links in mind
wireless links less reliable
Wireless Application
Protocol cont.
wireless devices limited in power (batteries)
compromised features;
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small keypad/keyboard
small display
limited data storage
standard IP cannot be used with mobile
devices efficiently - in some cases not
possible at all (800 x 600 page on a mobile in
true colour)
WAP
WAP
Cellular
(GPRS,
SMS)
IP
Packet Data
Infrastructure
WAP
Gateway
Provides
translation
between WAP
and IP
Applications:
Banking, ebusiness, weather,
news
Internet
Bluetooth technology
access
to LAN
2.4 GHz
Licence-free
laptop
1600 frequency
hops per second
cellular
network
mobile
phone
Low Tx
power, low
cost, battery
operation
mouse
symmetric and
assymetric
connections
printer
laptop
* replaces proprietary cables that
connect devices together *
Establishing a
connection
two units within range can set up a
connection (piconet)
share a channel
unit that initiates connection is master

other unit assumes role of slave
any unit can be a master or a slave
can only be one master in a piconet
Establishing a
connection cont.
before connection, each unit in standby
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scanning frequencies every 1.28 secs
keeps power demands low
after initiation, full duty cycle implemented
communicates using 2.4 GHz wavelength
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global compatibility
two bands available; 23 channels and 79
channels
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selected by software depending on geography
Bluetooth Applications
automatic synchronisation of email, calendar,
telephone book, smartcard data
3-in-1 phone
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home cordless phone - when in proximity of home
base unit
business cordless phone - use internal network
conventional cellular phone
cordless headset
mobile computer conferencing
automatic tolling - quite controversial!
WAP Technology
Massive growth in Internet usage
Rapid growth in mobile voice/data
services
Everyone has a mobile!
Data transfer rates limited
Key features
licence-free standard of adapting
internet technology to meet wireless
constraints
Wireless Markup Language (WML) for
authoring
optimised protocol stack based on
HTTP and TCP
usable over a broad range of cellular
data bearers
Architecture
HTML
JavaScript
Wireless Application Environment
(WAE)
Wireless Session Protocol (WSP)
WML
used
here
HTTP
Wireless Transaction Protocol (WTP)
TLS SSL
TCP/IP
UDP/IP
Wireless Transport Layer Security (WTLS)
Wireless Diagram Protocol
(WDP)
User Datagram Protocol
(UDP)
Bearers: SMS, GPRS, 3G
etc.
Internet Model
Web
Server
Client
Web Browser
HTTP Request (URL)
CGI scripts
etc.
The
Internet
IP Stack
HTTP Response (HTML)
Internet Protocols
HTML,
JavaScript
WAP Model
Client
WAP user
agents
WAP
Protocol
stack
Wireless
Network
WSP
Request
(URL)
WSP
Response
(WML)
WAP Protocol
WAP
Gateway
Encode/
decode
Protocol
conversion
Web
Server
HTTP
Request
(URL)
CGI scripts
etc.
The
Internet
HTTP
Response
(WML)
Internet Protocol
WML,
JavaScript
What’s so special about
WAP?
WML is binary encoded so compact over
airwaves
Extensive use of caching during sessions to
minimise traffic
Handles data requests asynchronously
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avoids waiting for responses before handling next
user request
Designed to hold ‘long’ sessions
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session resumed at last point if radio link fails
WTP only sends broken packets of data
TCP always sends entire message again
Wireless device issues
Small display - WML structures docs in
‘decks’ and ‘cards’
card represents a single unit of interaction
with user
 deck is a service, represented by a
collection of cards
 well suited to small displays
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Limited input - WML requires minimal
keyboard functionality
Wireless device issues
cont.
Limited memory and CPU
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WML is primarily text-based and requires a
low hardware overhead
Limited battery power
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WAP transmissions minimised over air
Summary
E-business currently utilises desktop
technology
Massive potential to open new mobile
markets
Bluetooth enables easy device
connectivity, widening access to internet
based services
WAP is a protocol designed to address
the limitations of wireless devices