IT Systems Operating System EN230-1 Justin Champion C208 – 3273 .
Use of the Devices Justin Champion Room C208 - Tel: 3273 .
-
date post
22-Dec-2015 -
Category
Documents
-
view
217 -
download
2
Transcript of Use of the Devices Justin Champion Room C208 - Tel: 3273 .
Use of the Devices
Justin Champion
Room C208 - Tel: 3273www.staffs.ac.uk/personal/engineering_and_technology/jjc1
Using the data device
ContentsWhy use the methods
WAP I-mode
Benefits of themProblems with them
Using the data device
Internet The ability to display information on the Internet is its most
widely used feature World Wide Web (WWW) pages
Hyper Text Mark-up Language (HTML) eXtended Mark-up Language (XML) Math Mark-up Language (MathML)
Java Java Applets
Plug ins Extend the capabilities
Assumes A standard monitor (display size) Performance of the machine Audio support Storage Interactions
Using the data device
MoneyTo charge user to receive data a method must
be used to provide information to the userThe methods available for portable devices
are WAP I-Mode Java2Me HTML – New 3 and 2.5 G devices
Using the data device
These protocols are higher level in the OSI network stackTelling us that
They are independent of the technology that transfers and displays them
The receiving device just needs to have the knowledge of how to deal with the data
Newer devices with OS’s that are updatable can just download new technologies as it becomes available
If HTML is upgraded no need to replace the device
Using the data device
Wireless Application Protocol Widely pushed in Europe for use with GSM devices
“Surf the net surf the BT Cellnet” Developed as a standard and controlled by the WAP
forum www.wapforum.org
Intended to bring together developments which several manufacturers were working on.
They all recognised a requirement to present information on mobile devices
Motorola, Nokia, Siemens, Erricson and more Based on thin client technology with the server doing all
of the work WAP is a set of different protocols for communications
Using the data device
WAP Continued A number of parts need adding to the network
to allow WAP WAP aware handsets WAP Gateway
Versions 1.0 - 1998 1.1 - 1999 1.2 – 1999 2.0 - 2001
Using the data device
WAP Requirements Non-proprietary Interoperable Scalable Efficient Reliable Secure
WAP protocol stack was designed to be secure from day one
Using the data device WAP Continued
Infrastructure
BS
Phone Network
BS
WAP Gateway
Internet
WML Server
HTML Server
Filter
Using the data device
WAP Continued A device makes a request for a webpage from the
Internet Request is sent to the WAP Gateway The gateway then makes this request from the Internet server
If the server has content which is WAP enabled then this is returned Obviously as the content has been written for a WAP device
If the webpage is only available in HTML this is converted by the WAP gateway into WML
The WAP gateway compresses the content and this is returned to the requesting device
This allows for less bandwidth and time for the transmission
Using the data device WAP continued
Example of WML WML uses the concept of a deck of cards
The entire deck is loaded into the device at once Each of these cards are then called
This demo is taken from a tutorial on the Internet (http://www.zvon.org/xxl/WMLTutorial/Examples/Example1/index.html, 2004)
<?xml version="1.0"?><!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.1//EN" "http://www.wapforum.org/DTD/wml_1.1.xml">
<wml> <card> <br/> <p><b><i>Miloslav Nic</i></b></p> <p><strong>Introduction to WML.</strong></p>
<do label='Click to visit other Zvon tutorials (XML,XSL,CSS,Perl,...)' type='accept'><go href='http://www.zvon.org/ZvonHTML/Zvon/zvonTutorials_en'/></do> </card> </wml>
<?xml version="1.0"?><!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.1//EN" "http://www.wapforum.org/DTD/wml_1.1.xml">
<wml> <card> <br/> <p><b><i>Miloslav Nic</i></b></p> <p><strong>Introduction to WML.</strong></p>
<do label='Click to visit other Zvon tutorials (XML,XSL,CSS,Perl,...)' type='accept'><go href='http://www.zvon.org/ZvonHTML/Zvon/zvonTutorials_en'/></do> </card> </wml>
Using the data device WAP Continued
Stack WAE
Allows the interpretation of WML Allows interaction with any application
WSP Allows the storing of session information, rather than
creating new session for each packet. Allows connection orientated and connectionless services
WTP Allows the messages to be brought together and
presented to the WSP layer Three classes
0 - unreliable 1- reliable with automated acknowledgements 2 – reliable, request response
WTLS This is similar to the SSL used on the internet for
secure communications WDP
This is the transport protocol the data is encapsulated into
Transport Layer (WDP)
Security Layer (WTLS)
Transaction Layer (WTP)
Session Layer (WSP)
Application Layer (WAE)
Using the data device WAP
WAE Application environment
User agents are runs at this level Allowing any software to use WAP
The most common is a user agent which interprets WML and display
Could be just as easy a client server environment, with a front end to the server
Using the data device WAP Continued
Infrastructure WAP Gateway
Acts as a firewall to the network Acts as a proxy to get the web pages Translation can be carried out on pages which are based on
HTML content Data will be compressed if required
Binary encoding
Using the data device WAP Continued
Usage WAP is increasingly used on phones
Not for displaying information but for downloading ring tones 30 Million hits per day in September, 2003 www.text.it/wap/default.asp?intPageId=580
WAP got bad press when it was first launched as a information service Service was slow and unreliable
A lot of the blame for this lay with the service providers not the technology A connection has to be made each time you start a WAP session, this does
take time Expensive to use
The business model used charges you for the time you view a page Original images were sent as Wireless BMP (WBMP)
In version 1.1 these images are black and white only
Using the data device
WAP Continued Will also increase its usage as interfaces improve It was difficult with older phones to select what you
wanted Even harder to type it !
New device use touch screen technology Virtual keyboards onboard
These will allow a better HCI experience
Using the data device
WAP Usage WAP is not WML
WML is just one use of the WAP stack WAP is intended to be a transport protocol for mobile devices Available on all networks
Not specific to GSM Most commonly used to view WML pages
There is a user agent installed on the device to display the WML data
WML data can be compressed into binary XML, to decrease the amount of time required for transmission
Using the data device
i-Mode Developed and owned by a single company
NTT DoCoMo (translated to “Anywhere”) I in i-mode is “information” Launched in Japan in 1999 Only available in the Japanese market
This is changing with European and American companies considering using it now
Based on the premise that you only pay for the data you receive (like GPRS)
Using the data device
i-Mode Was developed to allow extra revenue for NTT
They required the money to update there old telecommunication infrastructure, similar to GPRS
Created by Mari Matsunaga She had no background in computing or telecommunications
She was a magazine editor by training!
Is a service portal and not a protocol Owned and run by NTT and only subscribers can use
these services Gives a monopoly to NTT
It is not a open standard, but devices showing the i-mode symbol are capable of connecting to the portal
Using the data device
i-Mode Based on a packet based service Uses the NTT Personal digital cellular (PDC)
infrastructure This is similar to GSM Based on TDMA
Voice and data are transmitted using packets Operates at 800Mhz and 1500Mhz frequencies Transmission speeds are
5.6 kbps and 9.6 kbps
Using the data device
i-Mode infrastructure packet based
BS
PPM
BS
PGWM-SCP M-PGWi-MODEServer
Internet
Using the data device i-Mode Infrastructure parts explained
Mobile Station (MS) The actual communicating device
Base station (BS) Base station, allow the transmission and receipt of packets over the air
interface Packet Processing Module (PPM)
This part is responsible for the management of the packets sent to and received by the MS
Packet Gateway Module (PGW) Provides the functionality to connect to other packet switched networks
Internet Private LANS Other public packet switched networks
Using the data device i-Mode Infrastructure parts explained
Mobile Message Packet Gateway Module (M-PGW) This device is responsible for the terminating of communications with the
device i-MODE uses a different transport protocol inside the network to reduce the
overhead from the usual TCP. This is Transfer Layer Protocol (TLP) TLP increases the ratio of data to header and reduces the amount of
delivery receipts sent The M-PGW handles the conversion between the packet types for coming
in or and gong to the Internet Mobile Service Control Point (M-SCP)
Authenticates and approves packet communications to the device i-MODE server
Either supplies the data from the local servers or connects to the internet to gain the required pages
Using the data device
i-Mode very successful The use of I-Mode is not only successful but profitable
The end user pays a monthly subscription Services are offered which require additional payment
News services Football results Ticket ordering NTT
Take commission for on-line sales of about 10% The user pays for receiving the data per packet (128 bytes) Slow connection speeds max 9.6 Kbps
Using the data device Logic dictates it should fail
Why does it not The main issue is that the amounts charged are small
Micro Payments This means that the end user does not notice how much they are spending
600 packets of data is £1 Monthly subscription is £1
These little and often charges do not offend users as once they have downloaded a page they view it there leisure
Unlike WAP Japanese language does not have spaces, so not a problem with words
that will not fit onto the line wrapping to the next Usage
60% of worldwide mobile internet users use i-MODE 39% use WAP
marketed from day 1 at the youth market, WAP was initially pushed at the business market
Using the data device
i-Mode technology 9.6 Kbps data rate Always uses Compact HTML (cHTML) as the display format
Supports colour GIF images “cHTML is defined so that all basic operations can be done by a
combination of four buttons: Cursor Forward, Cursor Backward, Select, and Back/Stop (return to the previous page). Any functions that require two- dimensional focus pointing, like image map and table, are excluded from cHTML”
(Extract from the cHTML submission to the W3C. For details of cHTML, access http://w3.org/TR/1998/NOTE-compactHTML-19980209.)”
Using the data device
cHTML Is fully complaint with internet HTML
The conversion takes place transparently at the application layer Features will be removed like
Tables, jpg images, fonts and styles Advantage of this is any ‘normal’ web server can provide content for i-
MODE Web page size limit is 5KB, but this may change in the future Mail messages are also limited to 500 bytes
The excess is just thrown away! cHTML is NOT a Internet standard, it has been submitted but not
approved
Using the data device
Link If you wish to try out WAP
http://www.yospace.com/spedemo.html Links to the LIVE WAP Network
Using the data device
SummaryWhy not use HTML
WAP Software Hardware
I-Mode Software Infrastructure