THE GPRS
The General Packet Radio
Service (GPRS) is a new non-voice
value added service that allows
information to be sent and received
across a mobile telephone network. It
supplements today's Circuit Switched
Data and Short Message Service. It is
a step ahead to provide a massive
boost to mobile data usage and
usefulness. Payments are made as per
data volume, instead of per minute
pulse rate. You need to pay a fixed
rent around Rs. 750 per month, after
which you can surf for unlimited
hours. Except for one thing, as a
developing technology, the net
connection is a slow
process.
BENEFITS
- Surfing
the net;
emailing; all
through the
mobile.
Fast
transmission of text
documents,
spreadsheets,
photographs and
illustrations; mobile
chatting and on-line
games.
- A round
the clock net
connection, even
when you are on
the
move.
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FEATURES
SPEED
A GPRS can achieve speeds up to 171.2
kilobits per second (kbps) using all eight
timeslots at the same time. This is thrice
as fast as current data transmission
systems.
IMMEDIACY
GPRS facilitates instant connections
whereby information can be sent or received
immediately as the need arises, subject to
radio coverage. No dial-up modem connection
is necessary.
NEW APPLICATIONS, BETTER
APPLICATIONS
GPRS facilitates several new applications
that have not previously been available
over GSM networks due to the limitations in
speed of Circuit Switched Data (9.6 kbps)
and message length of the Short Message
Service (160 characters). GPRS will fully
enable the Internet applications you are
used to on your desktop from web browsing
to chat over the mobile network.
WHAT DO YOU NEED FOR A GPRS
?
- To begin
with, a mobile
phone or terminal
that supports
GPRS.
A
subscription to a
mobile telephone
network that supports
GPRS. ยง Knowledge of
how to send and/ or
receive GPRS
information using
their specific model
of mobile phone,
including software
and hardware
configuration.
A
destination to send
or receive
information through
GPRS. Whereas with
SMS this was often
another mobile phone,
in the case of GPRS,
it is likely to be an
Internet address,
since GPRS is
designed to make the
Internet fully
available to mobile
users for the first
time.
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KEY NETWORK FEATURES OF GPRS
PACKET SWITCHING
GPRS
involves overlaying a packet based air interface on the
existing circuit switched GSM network. This gives the user
an option to use a packet-based data service. With GPRS,
the information is split into separate but related
"packets" before being transmitted and reassembled at the
receiving end.
SPECTRUM EFFICIENCY
Efficient use of scarce radio resources means that large
numbers of GPRS users can potentially share the same
bandwidth and be served from a single cell. The actual
number of users supported depends on the application being
used and how much data is being transferred. Because of the
spectrum efficiency of GPRS, there is less need to build in
idle capacity that is only used in peak hours. GPRS
therefore lets network operators maximise the use of their
network resources in a dynamic and flexible way, along with
user access to resources and revenues.
INTERNET AWARE
GPRS fully enables Mobile Internet functionality by
allowing inter-working between the existing Internet and
the new GPRS network.
LIMITATIONS OF GPRS
LIMITED CELL
CAPACITY FOR ALL USERS
There are only limited radio resources that can be deployed
for different uses- use for one purpose precludes
simultaneous use for another. For example, voice and GPRS
calls both use the same network resources. The extent of
the impact depends upon the number of timeslots, if any,
that are reserved for exclusive use of GPRS.
SPEEDS MUCH LOWER IN
REALITY
Achieving the theoretical maximum GPRS data transmission
speed of 171.2 kbps would require a single user taking over
all eight timeslots without any error protection.
Additionally, the initial GPRS terminals are expected to be
severely limited- supporting only one, two or three
timeslots. The bandwidth available to a GPRS user will
therefore be severely limited.
APPLICATIONS OF GPRS
A wide range of corporate and consumer
applications are enabled by nonvoice mobile services
such as SMS and GPRS.
CHAT
Because of its synergy with the Internet, GPRS would allow
mobile users to participate fully in existing Internet chat
groups rather than needing to set up their own groups that
are dedicated to mobile users. Since the number of
participants is an important factor determining the value
of participation in the newsgroup, the use of GPRS here
would be advantageous.
TEXTUAL AND VISUAL
INFORMATION
You can receive information, which is in the form of not
only text, but maps, graphs or other visuals.
STILL IMAGES
Still images such as photographs, pictures, postcards,
greeting cards and presentations, static web pages can be
sent and received over the mobile network as they are
across fixed telephone networks. It will be possible with
GPRS to post images from a digital camera connected to a
GPRS radio device directly to an Internet site, allowing
near real-time desktop publishing.
MOVING IMAGES
You will also be able to receive moving images and receive
transmission from anywhere.
WEB BROWSING
You will also be able to use the GPRS for browsing the net.
DOCUMENT SHARING/ COLLABORATIVE WORKING Mobile data
facilitates document sharing and remote collaborative
working. This lets different people in different places
work on the same document at the same time.
AUDIO
Dictating to a mobile phone, would simply not give
sufficient voice quality to allow transmission to be
broadcast or analyzed for the purposes of background noise
analysis or voice printing. Since even short voice clips
occupy large file sizes, GPRS or other high speed mobile
data services are needed.
JOB DISPATCH
Non-voice mobile services can be used to assign and
communicate new jobs from office-based staff to mobile
field staff. Customers typically telephone a call center
whose staff take the call and categorize it. Those calls
requiring a visit by field sales or service representative
can then be escalated to those mobile workers.
CORPORATE EMAIL
With up to half of employees typically away from their
desks at any one time, it is important for them to keep in
touch with the office by extending the use of corporate
email systems beyond an employee's office PC. Since GPRS
capable devices will be more widespread in corporations
than amongst the general mobile phone user community, there
are likely to be more corporate email applications using
GPRS than Internet email ones whose target market is more
general.
INTERNET EMAIL
Internet email services come in the form of a gateway
service where the messages are not stored, or mailbox
services in which messages are stored. In the case of
gateway services, the wireless email platform simply
translates the message from SMTP, the Internet email
protocol, into SMS and sends to the SMS Center. In the case
of mailbox email services, the emails are actually stored
and the user gets a notification on their mobile phone and
can then retrieve the full email by dialing in to collect
it, forward it and so on.
By linking Internet email with an alert mechanism such as
SMS or GPRS, users can be notified when a new email is
received.
REMOTE LAN ACCESS
Remote LAN applications encompasses access to any
applications that an employee would use when sitting at
their desk, such as access to the intranet, their corporate
email services such as Microsoft Exchange or Lotus Notes
and to database applications running on Oracle or Sybase or
whatever. The mobile terminal such as handheld or laptop
computer has the same software programs as the desktop on
it, or cut down client versions of the applications
accessible through the corporate LAN. This application area
is therefore likely to be a conglomeration of remote access
to several different information types- email, intranet,
databases. This information may all be accessible through
web browsing tools, or require proprietary software
applications on the mobile device. The ideal bearer for
Remote LAN Access depends on the amount of data being
transmitted, but the speed and latency of GPRS make it
ideal.
FILE TRANSFER
You may download sizeable data across the mobile network.
This data could be a presentation document for a traveling
salesperson, an appliance manual for a service engineer or
a software application such as Adobe Acrobat Reader to read
documents. The source of this information could be one of
the Internet communication methods such as FTP (File
Transfer Protocol), telnet, http or Java- or from a
proprietary database or legacy platform. Irrespective of
source and type of file being transferred, this kind of
application tends to be bandwidth intensive. It therefore
requires a high-speed mobile data service such as GPRS,
EDGE or 3GSM to run satisfactorily across a mobile network.
HOME AUTOMATION
Home automation applications combine remote security with
remote control. Basically, you can monitor your home from
wherever you are- on the road, on holiday, or at the
office. If your burglar alarm goes off, not only do you get
alerted, but you get to go live and see who are
perpetrators are and perhaps even lock them in. You can
program your video, switch your oven on so that the
preheating is complete by the time you arrive home and so
on. Your GPRS capable mobile phone really does become like
the remote control devices we use today for our television,
video, hi-fi and so on. As the Internet Protocol (IP) will
soon be everywhere- not just in mobile phones because of
GPRS but all manner of household appliances and in every
machine- these devices can be addressed and instructed. A
key enabler for home automation applications will be
Bluetooth, which allows disparate devices to inter
work.
WHAT IS BLUETOOTH TECHNOLOGY
?
Bluetooth, named after the renowned Danish
King, Harold Bluetooth, is a short-range wireless
connectivity standard.
Bluetooth is capturing the minds of the present day
technologists, as a technology enabler for the wireless
unification of a wide variety of portable devices like
mobile PCs, mobile phones and the like. It does away with
the cables and enables voice and data transfer between the
devices through wireless networks called piconets.
The primary segments identified for Bluetooth application
are: Cellular & PCS Mobile Phones, Digital Cordless
Phones, Data Access Points, PC Cards and Adapters ,
Notebook & Desktop PCs, Handheld PCs & Palm
Companions / PDA s, Digital Still Cameras, Output
Equipment, Automotive and Industrial & Medical
applications.
The technology behind it:
Bluetooth is a Radio Frequency (RF) specification for
short-range, point-to-multi-point voice and data transfer.
An advantage of Bluetooth is it's similarity to many other
specifications already deployed and it's borrowing of many
a feature from these specifications. The 2.4GHz band is
used by IEEE 802.11 to enable wireless LAN connectivity.
Bluetooth borrows specifications to enable file sharing and
data transfers between devices from IrDA (a wireless
specification that uses InfraRed light to connect devices).
HomeRF SWAP, a specification aimed at small network of
devices for the home environment, is another source for
Bluetooth.
It is omni-directional and has a present nominal link range
of 10cm to 10m, which can be extended to 100m, with
increased transmitting power. Bluetooth operates in the
2.4GHz Industrial-Scientific-Medical (ISM) Band and uses a
Frequency Hop (FH) spread spectrum technology in which
packets are transmitted in defined time slots on defined
frequencies. A full duplex information interchange rate of
upto 1Mbps may be achieved in which a Time-Division Duplex
(TDD) scheme is used.
A Bluetooth
System:
- A Radio Unit -
consisting of a radio
transceiver, which provides the
radio, link between the Bluetooth
devices.
- A Baseband Unit - a
hardware consisting of flash
memory and a CPU. This interfaces
with the radio unit and the host
device electronics.
- Link Management Software
- a driver software or firmware
which enables the application
software to interface with the
baseband unit.
- An Application Software
- this implements the user
interface and is the application
that can run on
wireless.
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BLUE TOOTH USAGE MODELS
The usage model being presented below are
those which have been identified by the Bluetooth
SIG's marketing group and helps us to get a peep into
the vast areas of application of this wonderful
standard.
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The
three-in-one phone: It can
work as cordless phones connecting to
the public switched telephone network
at home and office and thus incurring
the fixed line charge. It could
function as a walkie-talkie with
other telephones in the same office
or building, without incurring any
charge. This telephone can also
connect to the cellular
infrastructure and function as a
cellular phone, incurring cellular
charges. At home, your phone
functions as a portable phone (fixed
line charge). When you're on the
move, it functions as a mobile phone
(cellular charge). And when your
phone comes within range of another
mobile phone with built-in Bluetooth
wireless technology, it functions as
a walkie-talkie (no telephony
charge).
The
Internet Bridge: In this
usage model, mobile phone or cordless
modem functions as a modem to the PC,
providing dial-up networking and fax
capabilities without a need for
physical connection to the PC. Use
your mobile computer to surf the
Internet wherever you are, and
regardless of whether you're
cordlessly connected through a mobile
phone (cellular) or through a
wire-bound connection (e.g. PSTN,
ISDN, LAN, xDSL).
The
Interactive Conference:
Here, multiple data terminals, use a
Local Access Network (LAN) access
point as a wireless connection to a
LAN. Once connected, the data
terminals operate as if they were
connected to the LAN via dialup
networking. The terminals can access
all of the services provided by the
LAN. In meetings and conferences you
can transfer selected documents
instantly with selected participants,
and exchange electronic business
cards automatically, without any
wired connections.
The file transfer usage model offers the
ability to transfer data objects from one
device to another. Object types include,
among others,
***.xls,***.ppt,***.wav,***.jpg,***.doc
files or entire folders, directories or
streaming data formats. Also, this offers a
possibility to browse the contents of the
folders on a remote device.
The
Ultimate Headset: The
Headset, can be wirelessly connected
for the purpose of acting as a remote
device's audio input and output
interface .The headset increases the
freedom of movement while maintaining
privacy. The headset can be typically
used with a cellular headset,
cordless handset or personal computer
for audio input and output. This
headset will also have the ability to
answer incoming calls and then
terminate them without physically
manipulating the telephone
handset.
Connect your wireless headset to your
mobile phone, mobile computer or any wired
connection to keep your hands free for more
important tasks when you're at the office
or in your car.
The
Automatic Synchronizer:
This provides a device-to-device
synchronization of the personal
information management (PIM)
information. Synchronization requires
business card, calendar and task
information to be transferred and
processed by computers, cellular
phones and PDA s, utilizing a common
protocol and format. This involves,
automatic synchronization of your
desktop, mobile computer, notebook
(PC-PDA and PC-HPC) and your mobile
phone. For instance, as soon as you
enter your office, the address list
and calendar in your notebook will
automatically be updated to agree
with the one in your desktop, or vice
versa.
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IrDA AND BLUETOOTH
IrDA-Data (IrDA -> Infra-red Data
Association) is another short-range wireless
connectivity standard with an installed base of 50
million units, by now. IrDA is a point-to-point,
narrow angle (30 degree cone), ad-hoc transmission
standard designed to operate over a distance of 0 to
1 meter and at speeds of 9.6kbps to 4Mbps, which is
expected to increase to 16Mbps.
While the application areas of Bluetooth and IrDA overlap,
they are not competitive standards, necessarily. The short
range, narrow angle of IrDA allows the user to aim, in
point-and-shoot style at a targeted recipient, for example
in a conference hall. Close proximity to the other person
is natural in a business card exchange situation and the
short range is an advantage of IrDA for such
applications.
The directional nature of IR enables a low level security
because of direct line-of-sight nature; but it provides
for, no security at the link level. There are security
loopholes as it is possible to eavesdrop on a conversation
by detecting reflected light and filtering out the
surrounding ambient noise.
In contrast, Bluetooth addresses the security concerns by
providing authentication and encryption in its baseband
protocol. Authentication relies on a challenge-response
protocol utilizing a secret key, personal identification
number or PIN. Bluetooth devices talking to one another
should have the same PIN. The protocol allows each device
to authenticate the other. After the devices are
authenticated it is possible to encrypt the transmission
for added security.
Thus, it is expected that while in some devices both IR and
Bluetooth may co-exist, for the other applications, the
choice of Bluetooth and IR will be based on the
applications and required usage models.
Mind-boggling technology like the Bluetooth and GPRS, is on
its way to make communications in the future, a completely
different ball game. A ball game with a win-win situation.
Pave way for the future with these technologies
then. Curtsy www compareindia com
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