76
12.3.2 Security
A company’s information is sensitive and hence it is important that the integrity of the
information is not compromised. Sending data over the PSTN network in its analogue form is not
secure, since the data is not encrypted. Only a very small number of modems are capable of
encrypting data, and these carry a significant price premium.
Because GSM is a digital technology, it is inherently more secure. As part of the GSM standard,
both data and voice transmission are encrypted for transmission across the network. This has been
the key strength for GSM as it provides peace of mind for users, without the need for additional
expenditure on expensive hardware and software.
12.3.3 Interworking with ISDN
One of the key advantages that GSM can offer users, is its ability to interwork with ISDN. This is
a core feature of the GSM standard, which has been developed to interwork seamlessly with ISDN.
Interworking between the ISDN and GSM networks is made possible by using a technique know
as rate adaptation. If the ISDN terminal adaptor being called by the GSM terminal is capable of
supporting V.110, it can adapt the 9.6 kbps data from the GSM terminal into 64 kbps ISDN
data. This is achieved by adding additional bits to the GSM data effectively packing out the data.
12.3.4 Quick call set-up
GSM was developed to interwork with the Integrated Services Digital Network (ISDN). ISDN
uses a technique known as rate adaptation to convert the slower GSM data up to 64 kbps ISDN
data using the International Telecommunications Union (ITU) V.110 rate adaptation protocol, ,
which is a standard for ISDN terminals. As a result when a data call is made from GSM handset to
an ISDN terminal adapter, the quick call set-up capability of ISDN can be utilised.
GSM Data makes it possible to send data or fax information over the GSM network. When
making a data call, the user simply dials the number they wish to send information to. The call is
connected to a gateway located at the GSM network operator, and then the gateway takes care of
the translation between the different kinds of networks, such as PSTN, ISDN or X.25 networks.
Currently the data transmission speed supported is up to 9.6 kbps, but with new GSM
technologies being developed this will increase.
12.3.5 Easy to Use
It is easy for international travellers to use GSM Data. The user does not have to worry about
selecting the correct telephone connector, ensuring that the modem is approved for connection to
the PSTN within that country, or can deal with potential line quality and integrity issues for use
over long distances. All this can be side stepped by using GSM, where the user is able to use their
equipment in the way they normally would.
Using GSM also provides for a faster response time for mobile employees when travelling. Used in
this way, GSM can provide a real competitive advantage to an organization. For example, sales
people out in the field can send information to relevant parties immediately. This can allow a
company to differentiate itself from its competitors, by its ability to respond to their customers’
needs in a time frame that meets (or exceeds) their requirements.
12.3.6 GSM Network
The GSM network can be divided into three broad parts:
