FRA:
http://www.mobilegprs.com/whatis.htm
What is GPRS?
Key User Features of GPRS
The General Packet Radio Service (GPRS) is a new nonvoice 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. GPRS is NOT related to GPS (the Global Positioning System),
a similar acronym that is often used in mobile contexts. GPRS has several
unique features which can be summarized as:
SPEED
Theoretical maximum speeds of up to 171.2 kilobits per second (kbps) are
achievable with GPRS using all eight timeslots at the same time. This is
about three times as fast as the data transmission speeds possible over
today's fixed telecommunications networks and ten times as fast as current
Circuit Switched Data services on GSM networks.
IMMEDIACY
GPRS facilitates instant connections whereby information can be sent or
received immediately as the need arises. No dial-up modem connection is
necessary. This is why GPRS users are sometimes referred to be as being
"always connected". Immediacy is one of the advantages of GPRS (and SMS)
when compared to Circuit Switched Data. High immediacy is a very important
feature for time critical applications such as remote credit card
authorization where it would be unacceptable to keep the customer waiting
for even thirty extra seconds.
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). These applications, described later in this white paper,
range from web browsing to file transfer to home automation- the ability to
remotely access and control in-house appliances and machines.
SERVICE ACCESS
To use GPRS, users specifically need:
a.. a mobile phone or terminal that supports GPRS (existing GSM phones do
NOT support GPRS)
b.. a subscription to a mobile telephone network that supports GPRS
c.. use of GPRS must be enabled for that user. Automatic access to the
GPRS may be allowed by some mobile network operators, others will require a
specific opt-in
d.. knowledge of how to send and/ or receive GPRS information using their
specific model of mobile phone, including software and hardware
configuration (this creates a customer service requirement)
e.. 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. From day one,
GPRS users can access any web page or other Internet applications- providing
an immediate critical mass of uses.
Having looked at the key user features of GPRS, lets look at the key
features from a network operator perspective.
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. To supplement a circuit switched network
architecture with packet switching is quite a major upgrade. However, as we
shall see later, the GPRS standard is delivered in a very elegant manner-
with network operators needing only to add a couple of new infrastructure
nodes and making a software upgrade to some existing network elements.
With GPRS, the information is split into separate but related "packets"
before being transmitted and reassembled at the receiving end. Packet
switching is similar to a jigsaw puzzle- the image that the puzzle
represents is divided into pieces at the manufacturing factory and put into
a plastic bag. During transportation of the now boxed jigsaw from the
factory to the end user, the pieces get jumbled up. When the recipient
empties the bag with all the pieces, they are reassembled to form the
original image. All the pieces are all related and fit together, but the way
they are transported and assembled varies. The Internet itself is another
example of a packet data network, the most famous of many such network
types.
SPECTRUM EFFICIENCY
Packet switching means that GPRS radio resources are used only when users
are actually sending or receiving data. Rather than dedicating a radio
channel to a mobile data user for a fixed period of time, the available
radio resource can be concurrently shared between several users. This
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 maximize the
use of their network resources in a dynamic and flexible way, along with
user access to resources and revenues.
GPRS should improve the peak time capacity of a GSM network since it
simultaneously:
a.. allocates scarce radio resources more efficiently by supporting
virtual connectivity
b.. migrates traffic that was previously sent using Circuit Switched Data
to GPRS instead, and
c.. reduces SMS Center and signaling channel loading by migrating some
traffic that previously was sent using SMS to GPRS instead using the GPRS/
SMS interconnect that is supported by the GPRS standards.
INTERNET AWARE
For the first time, GPRS fully enables Mobile Internet functionality by
allowing interworking between the existing Internet and the new GPRS
network. Any service that is used over the fixed Internet today- File
Transfer Protocol (FTP), web browsing, chat, email, telnet- will be as
available over the mobile network because of GPRS. In fact, many network
operators are considering the opportunity to use GPRS to help become
wireless Internet Service Providers in their own right.
The World Wide Web is becoming the primary communications interface- people
access the Internet for entertainment and information collection, the
intranet for accessing company information and connecting with colleagues
and the extranet for accessing customers and suppliers. These are all
derivatives of the World Wide Web aimed at connecting different communities
of interest. There is a trend away from storing information locally in
specific software packages on PCs to remotely on the Internet. When you want
to check your schedule or contacts, instead of using something like "Act!",
you go onto the Internet site such as a portal. Hence, web browsing is a
very important application for GPRS.
Because it uses the same protocols, the GPRS network can be viewed as a
sub-network of the Internet with GPRS capable mobile phones being viewed as
mobile hosts. This means that each GPRS terminal can potentially have its
own IP address and will be addressable as such.
SUPPORTS TDMA AND GSM
It should be noted right that the General Packet Radio Service is not only a
service designed to be deployed on mobile networks that are based on the GSM
digital mobile phone standard. The IS-136 Time Division Multiple Access
(TDMA) standard, popular in North and South America, will also support GPRS.
This follows an agreement to follow the same evolution path towards third
generation mobile phone networks concluded in early 1999 by the industry
associations that support these two network types.
--
Mvh - Lars Brink
I have only been wrong once - that was when I thought that I was wrong.