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;  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

Bluetooth Applications: VoIP, browsing, multimedia 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;  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 IP Cellular (GPRS, SMS)

Packet Data Infrastructure

Applications: Banking, e business, weather, news Provides translation between WAP and IP

WAP Gateway

Internet

Bluetooth technology

access to LAN 1600 frequency hops per second mouse symmetric and assymetric connections 2.4 GHz Licence-free laptop laptop cellular network mobile phone Low Tx power, low cost, battery operation printer

* 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  scanning frequencies every 1.28 secs  keeps power demands low after initiation, full duty cycle implemented communicates using 2.4 GHz wavelength  global compatibility two bands available; 23 channels and 79 channels  selected by software depending on geography

Bluetooth Applications

automatic synchronisation of email, calendar, telephone book, smartcard data 3-in-1 phone  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

HTML JavaScript HTTP

Architecture

Wireless Application Environment (WAE) Wireless Session Protocol (WSP) Wireless Transaction Protocol (WTP)

WML used here

TLS SSL TCP/IP UDP/IP Wireless Transport Layer Security (WTLS) Wireless Diagram Protocol (WDP) User Datagram Protocol (UDP) Bearers: SMS, GPRS, 3G etc.

Client Web Browser

Internet Model

IP Stack HTTP Request (URL)

The Internet

HTTP Response (HTML)

Internet Protocols

Web Server CGI scripts etc.

HTML, JavaScript

WAP user agents WAP Protocol stack Client

WAP Model

Wireless Network WAP Gateway HTTP Request (URL) Encode/ decode WSP Request (URL)

The Internet

Protocol conversion WSP Response (WML) HTTP Response (WML) Web Server CGI scripts etc.

WML, JavaScript WAP Protocol Internet Protocol

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  avoids waiting for responses before handling next user request Designed to hold ‘long’ sessions  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 Limited input - WML requires minimal keyboard functionality

Wireless device issues cont.

Limited memory and CPU  WML is primarily text-based and requires a low hardware overhead Limited battery power  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