Tiscali 2009 Annual Report Download - page 207

Tiscali Group: Annual Report 2009
206
V
VAS
Acronym for Value-Added Services; services with
added value provide a greater level of function
compared with the basic transmission services
offered on a telecommunications network for the
transfer of information between terminals. These
include switched analogue voice communica-
tions via cable or wireless, a direct digital point
to point network “unrestricted” at 9600 bits/s;
packet switching (called virtual); analogue tran-
smission and direct broadband of TV signals and
extra services, such as closed user groups; call
waiting; reverse charging; call announcement
and identification of caller number. The value ad-
ded services provided over a network, from termi-
nals or specialist centres include exchange servi-
ces, messaging (MHS) (which can also be used
for commercial documents in accordance with a
predetermined format); electronic user directori-
es, network and terminal addresses; e=mail; fax,
teletext, videotext and videophone. Value added
services may also include voice telephony value
added services such as free numbers or paid te-
lephone services.
VISP
Acronym for Virtual Internet Service provision
(sometimes also called Wholesale ISP). This is
selling on Internet services purchased wholesale
from an Internet Service Provider (ISP) that has
network infrastructure.
VoD
Acronym for Video On Demand. It is the supply
of television programs on request by a user for
payment of a subscription or of a sum for each
programme (a film, or a football match) purcha-
sed. Broadcast in a special way by satellite TV
and for cable TV.
VoIP
Acronym for Voice over internet Protocol, a digital
technology that enables the transmission of voice
packets through Internet, Intranet, Extranet and
VPN networks. The packets are carried accor-
ding to H.323 specifications, which are the ITU
(International Telecommunications Union) stan-
dard that forms the basis for data, audio, video
and communications on IP networks.
VPN
Acronym for Virtual Private Network, which can
be realised on Internet or Intranet. Data between
workstations and the server of the private network
is sent along common public Internet networks,
but using protection technologies against any in-
terception by unauthorised persons.
Virtual Unbundling of local loops or VULL
Procedure for accessing a local analogue net-
work by which, even in the absence of physical
infrastructures, the conditions and terms of ac-
cess under ULL terms are replicated. This is a
temporary access system that is usually replaced
by ULL.
X
xDSL
Acronym for Digital Subscriber Lines, a technolo-
gy that, by means of a modem, uses the normal
telephone twisted pair and transforms the tra-
ditional telephone line into a high speed digital
connection for the transfer of data. ADSL, ADSL
2, and SHDSL etc belong to this family of tech-
nologies.
W
Wi-Fi
Service for connection to the internet at high spe-
ed wirelessly.
Wi-Max
Acronym for Worldwide Interoperability for Micro-
wave Access: it is a technology that enables ac-
cess wireless access to broadband telecommuni-
cations. It ahs been defined by the WiMAX forum,
a world-wide consortium made up of the largest
companies in the fixed and mobile telecommuni-
cations field that has the purpose of developing,
promoting and testing the interoperability of sy-
stems based on IEEE standard 802.16-2004 for