Q. What is broadband?
A. It is a general term referring to access to fast data rates - usually greater than 2 Mbs

Q. What is a Metropolitan Area Network?
A. It is a network of ducting and fibre optic cable laid within a metropolitan area which can be used by a variety of businesses and organisations to provide services including but not limited to telecoms, Internet access, television, telematics and CCTV. Its components are Duct, Sub-duct, Dark Fibre Pairs and Co-location.

Q. What are ducts and sub-ducts?
A. A duct or sub-duct is a pipe, tube or conduit through which cables or wires are passed as illustrated in Figure 1. Each MAN will have 4 ducts. This requires a trench opening to install the ducts. A duct will contain 4 sub-ducts, as illustrated also in Figure 1. One of the sub-ducts will have a 48 pair optic fibre cable installed. These ducts protect the fibre and facilitate the installation of more fibre cables at a later stage without re-opening the pavement or road surface. Ducts are colour coded to allow for ease of identification.

Q. What are Dark Fibre Pairs
A. Fibre, a shortened way of saying 'optic fibre', is made of very pure glass. According to a prominent commentator, "Optical fibre is so clear and pure that if you looked through a wall of it 70 miles thick, you would be able to see a candle burning on the other side". Digital signals in the form of modulated light travel on the fibre for long distances. Dark Fibre is unused fibre through which no light is transmitted, or installed fibre cable that is not carrying a signal. Fibre is referred to as dark fibre pending the connection to the equipment to transmit data. Selection, installation and activation of this equipment, often referred to as 'lighting the fibre' is at the discretion of the Service Provider (SP). A cross section of the 48 pair fibre to be installed in the MAN.

Q. What is Co-location?
A. A Co-location facility, sometimes referred to as a 'data centre' is a network-connected, secure facility for the housing of telecommunications and IT infrastructure, Co-location involves the sub-letting of space in a safe and secure environment for a service providers equipment. A dark fibre service offering will require the provisions of a secure facility to locate the electronic equipment necessary to activate the fibre and any ancillary equipment the service provider needs. Service provider housing equipment at the co-location facility can avail of services such as power resilience, temperature control, fire detection and physical security systems. A co-location facility will be run on a service provider independent basis offering space and services to the service providers seeking to connect to the MANs and to each other. It will not be owned or controlled by any service provider. The co-location facilities may also serve to encourage new service providers to provide services to the communities served by the MANs.

Q. What are the types of MANs?
A. At the most basic level there are two communications delivery methods - wireline and wireless. Both delivery methods traditionally rely on a number of technologies. In order to promote availability of broadband and future proof investment, fibre has been proposed for delivering broadband services to high-density clusters of users such as business parks and for providing basic infrastructure for deploying other technologies. Fibre has the advantage of almost limitless capacity but as yet availability of fibre in Ireland is limited. The NDP is concerned with delivering a number of open access optic fibre based metropolitan area networks to increase capabilities. Although fibre offers the greatest potential as an access medium it must be emphasised that all current high capacity broadband access solutions (including xDSL and certain wireless technologies) have important roles to play, especially in managing a smooth migration from legacy networks (copper based) to the more fibre based network. These new MAN networks will offer resilience and the ability to distribute traffic load. Several service providers will have access to sub-ducts and fibre pairs to allow expansion of their own network infrastructures.

Q. Are there road excavations involved in MANs?
A. Historically telecommunications service providers have resisted infrastructure sharing, resulting in the frequent redigging of streets as new service providers come to market. These MANs will reduce the need for service providers to install their own ducting infrastructure, as these MANs will be operated on a principle of open access. To meet the requirements of information technology based communications networks, the following are general principles in terms of capacity, operational dependability and diversity, which are being applied:

Q. What is fibre?
A. It is the shortened name given to optic fibre which is made from pure glass and uses light to transmit information.

Q. What is xDSL?
A. This refers to Digital Subscriber Line a method of providing high speed data services over copper wires which are currently supporting a voice service.

Q. What does active mean?
A. It refers to the installation of electronic equipment and computer servers to build services on the MAN.

Q. What is a Base Station?
A. It is a facility to house equipment to deliver wireless services e.g. mobile phone.

Q. What is a Central Facility?
A. It is a facility where the local telephone exchange, switch, transmission equipment, etc. is located and is often referred to as a PoP (Point of Presence).

Q. What is resilience?
A. It is the ability to provide a backup service in the event of a disruption or breakdown.

Q. How is Fibre Optic Cable used?
A. Fibre is both a direct and indirect enabler of communications services through its integration with other communications technologies. There are two dominant direct fibre based technologies. OEoF (Optical Ethernet over Fibre) and SDH (Synchronous Digital Hierarchy). While both of these technologies use fibre as the final means of service delivery, they differ in their technical presentation and cost to the user and the infrastructure deployed by the service provider in the network. SDH as a technology is prevalent among high bandwidth users where service levels, redundancy and resilience are critical. Ethernet is typically a PC to PC based technology which due to its cost proposition is now finding favour in the SME and corporate markets, and because of the low deployment cost Ethernet is now being deployed in the home (FTTH - Fibre-to-the-Home) and offers extensive possibilities in this regard.

Q. What is OEoF?
A. Optical Ethernet over Fibre is based on Ethernet which is a protocol that was initially used for connecting computers, printers, workstations, servers etc. within the same building or campus. It is now the dominant protocol of enterprise networks, with as many as 90% of all network connections operating over Ethernet. Due to this large installed base, Ethernet installation and management are well understood by corporate IT departments. Optical Ethernet over Fibre can be defined as using the Ethernet protocol over fibre for access to or within a network. High bandwidth broadband applications such as Internet Browsing, Video on Demand and Voice over IP are very suitable contenders for deployment over OEoF. However with its significant install base in corporate networks OEoF will be primarily used for extending corporate networks across multiple office locations. Ultimately this will reduce network set-up and maintenance costs, as services can be shared across a number of offices, and a centrally located support group can see all network elements over the OEoF link. OEoF is also ideal for deployment of data services in residential environments, such as apartment blocks or housing developments where the fibre is extended to provide in-building distribution among the tenant. This residential model occurs where a service provider deploys service thus presenting all users with 'always on' Internet access, negating the need to dial up to browse. Service Providers can use OEoF as the local backbone to transfer customer traffic such as telephone calls or e-mail between sites and for hand over to other service providers. The transmission layers of the maturing Ethernet standards operate across advanced access networks that offer high capacity at low cost. The full duplex switch Ethernet IEEE 802.1D and 802.3x gives full speed point to point connections with no collisions and in theory no distance limitations. With the addition of IEEE 802.1Q protocol, virtual LAN's can be provided with privacy to give a fully functioning access solution built purely on Ethernet standards.

Q. What is duplex?
A. This is a telecommunications term meaning simultaneous two-way transmission.

Q. What does 'collision' mean?
A. It is the result of two workstations or PC's simultaneously sending information which bumps into each other corrupting both signals.

Q. What is IEEE?
A. It is the Institute of Electrical and Electronics Engineers.

Q. What is Voice over IP (VoIP)?
A. It is a method of delivering voice on Internet and data networks.

Q. What is Synchronous Digital Hierarchy (SDH)?
A. SDH refers to a group of fibre-optic transmission rates that can transport digital signals at different capacities. SDH applications are a set of international telecommunication standards for synchronous data transmission over fibre optic networks. Today, SDH transmission networks are widely deployed throughout the world, and form the basis of telecommunications carrier networks and service offerings. SDH is ideal to deliver other generally used protocols such as ATM and IP. Using these protocols on SDH gives the advanced services required and self healing. Self healing means that SDH provides for automatic network backup with 100% redundancy so that if there is a point of failure on your fibre ring your service remains unaffected. SDH is a telecommunications traffic interface that is equipment vendor independent. It is the first global standard in digital transmission over fibre. The key features of SDH are powerful network management and self-healing capability allowing service providers offer customers service level agreements.

Q. What is DSL (Digital Subscriber Line)?
A. It is a technology that exploits unused frequencies on copper telephone cable. DSL provides high-speed Internet access using regular telephone lines. It has the ability to move data over traditional copper telephone lines at speeds up to 6 MBS or six million bits per second. That's 140 times quicker than the fastest modems available today. In addition to its very high speed, DSL has many advantages over analogue connections. Unlike dial-up connections that require analogue modems to 'dial-in' to the service provider every time the user wants to retrieve e-mail or obtain access to the Internet, DSL connections are 'always on'. Another advantage is the ability to use the telephone at the same time as accessing the Internet; you don't have to choose between the two. The fibre/copper relationship exists where the fibre MANs will be used to provide the link to the central facility where the copper connections are located. This fibre circuit will then be broken into smaller segments for termination at the customer premises via copper connections. The primary DSL service offering is Internet access. As the Internet becomes an accepted tool for doing a growing number of household activities such as shopping, banking, bill paying, investing and learning, it is essential that residential users are provided 'always on' access. At the moment DSL is the optimum technology for residential broadband deployment due to the ubiquitous nature of the copper telephone line. However, a DSL connection works better when you are closer to the provider's central facility - the closer to the central facility the faster the connection. Using a DSL Internet connection and VPN (Virtual Private Networking), teleworkers can work more productively at home. A VPN allows private data to pass over the Internet and it's the underlying technology for connecting teleworkers to the office network via DSL. Downloading a 10Mb file, for example, takes 32 minutes using a 56 Kbps modem. Using a DSL connection, downloading a 10Mb file takes less than 20 minutes. DSL provides companies with the security and data transfer speeds necessary to facilitate employees working from home. For multi-tenanted premises (whether residential or corporate) DSL and fibre are very complimentary. DSL can be used to distribute data services within the premises. The DSL connections can be terminated in a basement for example, where the data is aggregated and transmitted back to the central facility over the fibre connection. There are two forms of DSL, each form comprising a number of flavours. 1. Asymmetrical Variations such as ADSL, G.Lite, RADSL and VDSL. Asymmetrical DSL offers differing upstream and downstream speeds between the network and customer. Certain forms can deliver up to 8Mbps from the network to the customer. However, the speed is dependent on the distance of the customer from the service provider central facility. 2. Symmetrical Variations such as SDSL, HDSL, HDSL-2 and IDSL. Symmetric DSL supports the same data rates for upstream and downstream traffic. The equal speeds make this ideal for LAN access, distributed applications, video-conferencing etc.

Q. What does LAN mean?
A. LAN is Local Area Network. It is a short distance based network typically serving a building or campus.

Q. What is Hybrid Fibre Coax (HFC)?
A. Residential Internet and online usage has managed to grow tremendously despite slow access speeds available through existing dial-up telephone modem connections, limited to 56 Kbps or less. Touted as an interactive extravaganza, surfing the World Wide Web more typically offers users a click-and-wait experience. The growing frustration of existing online users is driving demand for higher-speed connections. HFC networks were originally deployed by the cable television companies and were originally designed for video, which is a one-way transmission (as distinct from voice which is two-way). In recent years, these networks were upgraded to provide Internet services based on cable modems. HFC networks are a mix of fibre and copper-based infrastructure. The copper connection is usually installed from a street cabinet into the customer's premises while the fibre connection is installed from the street cabinet back to the service provider's central facility. Older cable networks have copper paths limiting the capacity of the networks unlike fibre based networks. HFC networks are designed to provide broadcast TV, voice and Internet access. Customers are presented with a separate cable television decoder box, a telephone socket an a cable modem, specifically designed for operation on HFC networks for Internet access. However, it should be pointed out that only one coaxial cable is required into the end-customer premises. The MANs currently being deployed will serve to provide a network upgrade path for the existing cable network operators who can purchase sub-duct or fibre to serve new areas or upgrade old network infrastructure - providing the fibre link from the street cabinets to the central facility. HFC is very important as it provides a viable alternative for those areas that can not be served by DSL, where HFC exists. To offer high-speed Internet services, a cable operator creates a data network that operates over its hybrid fibre/coax (HFC) plant. A typical cable network consists of a regional cable head end which feeds distribution hubs through a metropolitan area network fibre ring. A the distribution hub, signals are modulated onto analogue carriers and then transported over fibre-optic lines to nodes serving 500 to 1,000 homes. From the node, these signals are carried via coaxial cable to a home or business.