© gprshelp 2004 an introduction to gprs. © gprshelp 2004 contents what is gprs? gprs applications...
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© GPRShelp 2004
An Introduction ToGPRS
© GPRShelp 2004
Contents
What is GPRS? GPRS Applications GPRS Myths GPRS Services Email – the killer application Accessing your company LAN
© GPRShelp 2004
Contents What is GPRS?
How the GPRS network works What devices you can use How does it perform What are your connectivity
options
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What is GPRS - Overview
GPRS provides mobile data services such as Internet and WAP access
It is also used to provide other commercial services such as MMS (Multi-Media-Messaging).
GPRS is an upgrade to a GSM network to enable mobile data and hence coverage is similar to it’s host GSM network.
GPRS is also a packet network - “Packet” means that, rather than have a continuous circuit assigned for the duration of a data call, small blocks (packets) of data are transmitted as required.
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GPRS – A “packet” network The advantage of being a packet network is that
you can have a permanent ‘always on’ connection, sending and receiving data when required.
Voice customers keep their channel for the duration of the
call
GPRS customers’ data is broken down into small “packets”, sent
when there is a free timeslot, and then re-assembled to recreate the
original data
Time
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GPRS – A “packet” network Other advantages are that you can use more or less
channels as your data requirements vary.
Voice customers keep their channel for the duration of the
call
If there is a lot of data – more channels can be used – three in
this case.
For small amounts of data “occasional” packets of data are
sent.
Time
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What is GPRS overview Your GPRS device will contain the name of
a physical connection (the APN) to the GPRS network e.g. It could be the word “Internet” for the Internet connection.
All your data is then routed to/from this connection.
GPRSNetwork Internet
Firewall
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What Devices Can You Use?
Mobile Phones Laptop computers, Data Cards Telemetry Smartphones
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Mobile PhonesMany phone users are using GPRS everyday for
WAP – Here the user should experience faster connections and page display – charged only for data transfer – not for length of time connected.
MMS – Multi-media messaging or Picture messaging is charged by the message – if messages are sent as emails then they are charged at the Internet access rates.
Internet – Many GPRS phones may be used with a PC or PDA to provide Internet access.
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Data Cards Data Cards are GPRS modems that can plug into a PC or
PDA to provide GPRS connectivity. They have their own GSM SIM card and their own account.
They can be purchased in PC-card format for laptops or CF-card format for compatible PDAs.
GPRS cards usually have voice capability but it is often disabled.
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Telemetry Telemetry refers to unattended computerised equipment
communicating using GPS – e.g. an ATM machine connecting with a bank or a whether station regularly reporting temperatures etc.
Telemetry users have a choice of using either a PC card. mobile phone with cable or a special ruggedised GPRS modem.
These have a serial or USB data connection, a power connection and an external aerial connection.
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Smartphones Smartphones combine the functionality of a PDA and a
Mobile phone in a single device. Many smartphones compromise the specification of either
device or both to fit in one unit. i.e. they are physically too large compared with a phone and the display is too small compared with a PDA.
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How fast is GPRS?
How fast will a GPRS network be? What is “Optimisation” What is “Latency” and how it affects you Can I Rely on GPRS for critical services?
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How Fast? The speed quoted on GPRS devices is usually their
maximum theoretical speed and will NEVER be achieved in real life.
The actual speed of a GPRS connection will vary depending on many factors such as device capability, signal strength, congestion.
Typical speeds with recent devices will be around 30Kbps on an un-congested network.
At times data flow may seem to stop or be limited to a few kbps.
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Optimisation To speed up internet access, many GPRS networks
compress web pages to reduce data flow. If you compare a GPRS loaded web page to a standard
web page you may notice that the graphics are worse quality where they have been further compressed – both resolution and colour depth.
The speed to load an ‘optimised’ page may be 4-5 less than a standard page.
If you use encryption to access your company data – the optimisation will not work!
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Latency GPRS networks delay data more than many other forms
of data networks. The round trip delay may be anything from 500-1000ms
– not a problem for POP email or web browsing but may disrupt LAN access or audio/video conferencing.
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Reliability
GPRS availability is not guaranteed – especially as voice traffic often takes precedence over data users.
As with GSM speech calls you should be able to use GPRS whilst moving – but this can often be problematical.
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Services for Business
Accessing Company LANs Internet and Corporate Email Private APN – dedicated, private connections
to a GPRS network
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LAN access
VPN – Setting up a “Virtual Private Network” using secure encryption software is possible over GPRS. Performance is poor because of the “latency” of the GPRS connection and relatively slow data speeds.
Email Redirection to Internet email server WAP/Webmail Proprietary secure Internet services
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Security Virtual Private Networking provides a method for
businesses to utilise encryption to form a secure connection to their LAN across the Internet.
VPN can be used over many different bearers (dial-up, broadband and GPRS).
Once authenticated users can use their standard office applications to view email and browse their Intranet.
CorporateNetwork
VPN Firewall
Secure “tunnel” through Internet
GPRS Network Internet
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GPRS Applications
Internet (POP) email Web Browsing VPN Telemetry
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WAP
WAP phones can connect using GPRS This provides a quicker/better user
experience than dialling up using GSM data. WAP may be a good device to view emails
when travelling – either from a WAP capable Internet email platform or a company email system.
Connections may be encrypted for high security applications.
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Internet Access
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Email The killer application
Email on the move
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Internet (POP) email
To get good performance for mobile email consider the following:
The POP protocol is often used to download emails to you PC – downloaded emails are then
The device used to send emails is an SMTP server – your ISPs SMTP server may not work over GPRS in which case use your mobile operators SMTP server.
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Web Browsing
Web Browsing
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GPRS Services
WAP, Web browsing, Instant messaging, VPN, Telemetry
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Internet
Private APN
CustomerNetworkGPRS
Network
Large mobile users benefit from having a private connection (leased line) to a GPRS network.
Some operators allow voice + data traffic + SMS to share the leased line