What are the main Broadband technologies?
What is so interesting about MSS-CGC systems?
What is the digital divide?
The digital divide is the gap between those with effective access to digital technologies and those without. The digital divide is not a clear gap that divides a society into two groups: researchers report that disadvantages can take such forms as lower-performance computers, lower-quality or high-priced connections (i.e. narrowband or dialup connections), difficulty in accessing the Internet or exploiting technological advances in developing economies.
What are the main broadband technologies?
DSL: this stands for "Digital Subscriber Line." It is today the predominant broadband delivery technology, a medium for transferring data over normal phone lines and can be used to connect to the internet. xDSL refers to different variations of DSL, such as ADSL (asymmetric DSL) and VDSL (very high speed DSL). In October 2005, 80% of broadband subscribers in the EU25 used DSL to connect to broadband Internet
Cable modem: a cable modem is a device that enables you to link your PC to a local cable TV line and receive data at similar speeds to DSL. Cable currently accounts for about 16% of all broadband connections in the EU25.
Fibre optic: a technology that uses glass (or plastic) threads (fibres) to transmit data. A fibre optic cable consists of a bundle of glass threads, each of which is capable of transmitting messages modulated into light waves. Fibre optics has several advantages over traditional metal communications lines including virtually unlimited bandwidth.
Power line communications: using electric power supply lines to offer high speed internet access.
Cellular solutions rely on the radio cells already established or being established for “second generation” and “third generation” mobile communications networks. Designed initially to serve the needs of mobile users, including while they are on the move, these networks can also be employed to deliver service to fixed users.
Wireless local area networks (W-LAN) provide a shared access bi-directional radio carrier over a limited area, which can provide a service to any suitably-equipped user terminal within reach of the signal. A new variant is called Wi-Max.
Satellite solutions: satellites promise a ubiquitous delivery platform for broadcast and broadband services over any part of the earth’s surface, except where cover or terrain obscures the line-of-sight path to the satellite. They can be used to give direct access links to individual users, or for backhaul.
Why is resilience so important?
New York’s 9/11 attack, hurricane Katrina, the London and Madrid bombings or the Asian tsunami all revealed the same telecommunications failures. Depressingly, time and again, the telecommunications systems on which PPDR services depend have failed. Around the world, man-made or natural disasters regularly stress communications systems beyond breaking point. Problems include:
call volume spikes leading to congestion
lack of priority communications for emergency services
lack of back-up systems in the event of network failure
unfamiliarity with exceptional communication terminals such as satellite phones
lack of interoperability
the dearth of effective underground communications equipment
Given this multitude of issues, it is essential that Europe acquire telecommunications systems that meet the needs of those involved in PPDR and Critical Infrastructure Protection.
Communications systems that combine space- and ground-based components are ideally suited to meet these needs. The infrastructure needed for resilience is space-borne, and thus beyond the reach of man or nature.
What is interoperability?
Different users and emergency services must be able to communicate with one another in the same way that we expect one mobile phone operator to route our calls to any phone, irrespective of service. Today's emergency communications systems rely on a number of different technical standards and protocols, and all too often cannot talk to one another.
What does ubiquity mean?
At its simplest, ubiquity means theat the service should be available anywhere in Europe. A service that can reach a remote community as easily as an urban centre is ubiquitous and helps bridge the digital divide. Ubiquity is also essential for emergency services: the system must be available whether a bomb strikes a city centre, or a fire a remote mountain area.
What is an MSS-CGC system?
MSS-CGC stands for “Mobile Satellite System with a Complementary Ground System”. It is a 2-way communications system that seamlessly integrates a satellite component with a ground-based network. Voice calls and data are routed through ground-based network or the satellite, depending on availability or other criteria such as preferential access.
What is so interesting about MSS-CGC systems?
Satellite telephone systems work using special, dedicated hardware. Users need to buy, subscribe to and operate two different systems - for example, a GSM mobile phone and a satellite telephone. By contrast, MSS-CGC systems allow users to meet all their communications needs using a single terminal. The terminal decides which network to use, and switches back and forth between ground-based and space-based network depending as required.
The ground component provides access in difficult locations, such as urban canyons where the satellite is hidden. And, thanks to the satellite component, MSS-CGC services are ubiquitous. Users can access the service in remote areas, offshore or in the air. The space-based component also makes MSS-CGC impervious to disasters. It remains available even if the ground-based component is taken out. This means that MSS-CGC systems are uniquely able to serve the needs of emergency responders.
What is the S-Band?
The S band ranges from 2 to 4 GHz, crossing the imaginary boundary between UHF and SHF at 3.0 GHz. It is part of the microwave band of the electromagnetic spectrum. Within the S-Band, the ITU has allocated two discrete bands spanning 1980 to 2010 MHz and 2170 to 2200 MHz to mobile satellite services on a global basis. The reason why two band have been allocated is that two-way satellite communications require an uplink (from the ground up to the satellite) as well as a downlink.
