A National Broadband Network (NBN) is a national wholesale-only, open-access data network, a number of which are under development, most notably in Australia. The network is based on the premise that fixed line and wireless broadband connections are sold to retail service providers (RSP), who then sell Internet access and other services to consumers, with certain portions of the network being public, open and free or with a nominal fee in urban centres.
The key to any national broadband plan is to offer the ideal infrastructure mix to deliver fast broadband across a country as quickly as possible. The expected the technology mix can include Fibre-to-the-Node (FTTN), Fibre-to-the-Building (FTTB), Fibre-to-the-Home (FTTH) as well as existing Hybrid Fibre Coaxial (HFC) networks and other privately operated fibre broadband infrastructure, along with Fibre-to-the-Premises (FTTP), Satellite, Copper DSL (ADSL/VDSL/XDSL) and mobile technologies such as WiMAX, 3G, 4G/LTE and 5G fixed wireless. Other technologies will include long range and wide area wireless deployments attached to Fibre backbones.
The key factor for any network is the design of the network and its robustness and failover ability. Some of the key technologies used are:
Fibre to the Premises
Premises within the FTTP footprint are connected using Ethernet over a gigabit passive optical network (GPON) giving a peak speed of one gigabit per second. A fibre-optic cable, known as the "drop fibre", goes from the premises to the street ending at the top of a power pole or in an underground pit or corner exchange. The "drop fibre" cable joins a "local network" which links a number of premises to a splitter in the fibre distribution hub. A "distribution fibre" cable connects the splitter in the distribution hub to a fibre access node. The FTTP footprint includes all the Fibre Access Technologies including Fibre-to-the-Node (FTTN), Fibre-to-the-Building (FTTB), Fibre-to-the-Home (FTTH), Hybrid Fibre Coaxial (HFC) and Fibre-to-the-Street (FTTS). The key reasons Fibre is chosen over copper or even hybrid fibre/copper setups are:
A single optical fibre can carry 3,000,000 full-duplex voice calls or 90,000 TV channels.
Immunity to electromagnetic interference
Light transmission through optical fibres is unaffected by other electromagnetic radiation nearby. The optical fibre is electrically non-conductive, so it does not act as an antenna to pick up electromagnetic signals. Information traveling inside the optical fibre is immune to electromagnetic interference, even electromagnetic pulses generated by nuclear devices.
Low attenuation loss over long distances
Attenuation loss can be as low as 0.2 dB/km in optical fibre cables, allowing transmission over long distances without the need for repeaters.
Optical fibres do not conduct electricity, preventing problems with ground loops and conduction of lightning. Optical fibres can be strung on poles alongside high voltage power cables.
Material cost and theft prevention
Conventional cable systems use large amounts of copper. In some places, this copper is a target for theft due to its value on the scrap market. This is key in South Africa where copper theft is rife and with optical fibre having almost no resale value in stolen form, it is very rarely, if ever, stolen.
With the growing infrastructure of the GSM wireless networks, fixed wireless has also become a viable solution for broadband access. Businesses and homes can use fixed-wireless antenna technology to access broadband Internet using fixed wireless broadband. Because of the redundancy and saturation of the GSM network, antennas that can aggregate signal from multiple carriers are able to offer fail-over and redundancy. In rural areas where wired infrastructure is not yet available, fixed-wireless broadband has become a viable option for Internet access. Modern Fixed Wireless solutions now incorporate 3G, 4G/LTE, 5G and Long Range or Wide Area wireless solutions based on Fibre Backbones.
Fixed wireless services typically use a directional radio antenna on each end of the signal (e.g., on each building). These antennas are generally larger than those seen in Wi-Fi setups and are designed for outdoor use. Several types of radio antennas are available that accommodate various weather conditions, signal distances and bandwidths. They are usually selected to make the beam as narrow as possible and thus focus transmit power to their destination, increasing reliability and reducing the chance of eavesdropping or data injection. The links are usually arranged as a point-to-point setup to permit the use of these antennas. This also permits the link to have better speed and or better reach for the same amount of power.
Satellite Internet access is provided through communications satellites. Modern satellite Internet service is typically provided to users through geostationary satellites that can offer high data speeds, with newer satellites using Ka band to achieve downstream data speeds up to 50 Mbps. Further advancements to the technology are allowing for maximum speeds within the 10s to 100s of Gigabits per second.
Satellite allows for expansion of a broadband network to areas that are too remote or offer no viability for core ground based fixed access, and also offer a wide coverage area and quick installation making it perfect for rural areas. The satellites also offer the advantage of piggybacking other services such as VoIP, SDTV, HDTV, VOD and Datacasting. The satellites operate in the L, C, Ku or Ka frequency bands and have a coverage range up to 6,000km.
The only disadvantage of the satellite portion of an NBN is latency. Latency is the delay between requesting data and the receipt of a response, or in the case of one-way communication, between the actual moment of a signal's broadcast and the time it is received at its destination. The amount of latency depends on the distance travelled and the speed of light. Light including wireless radiation would take about 0.12 seconds to reach a geostationary satellite (at 36,000 km above the equator), so nearly 1/4 second for a round trip. Latency is the main difference between a standard terrestrial based network and a geostationary satellite network. The round trip latency of a geostationary satellite communications network is up to 20 times that of a terrestrial based network. The speed of the network is perfect for most uses of the internet except for any latency sensitive applications such as gaming.
Driving Factors for a National Broadband Network
The soaring demand for new high-speed Internet access, HDTV, and 3DTV has motivated international operators to build networks that allow higher broadband speeds. A number of countries have recognized the value of the digital economy to their future development. A national broadband network (NBN) helps a country boost economic growth.
According to research by the World Bank, the return on investment in broadband is significant. A 10% increase in broadband penetration brings 1.2% growth in GDP for developed countries and 1.4% growth in GDP for developing countries. The development and deployment of a national broadband network also promotes and grows employment. Research by the World Bank shows that every $5 billion invested in broadband creates about 100,000 jobs in the short term. A 10% increase in broadband penetration creates more than 2 million jobs.
In some cases, broadband can help reduce poverty in the countryside, narrow the digital divide, and strengthen social communication. Broadband can help in areas such as construction, population management, healthcare, insurance, and welfare. It is also a focus on the future. Broadband is a basic infrastructure in modern society, just like roads. Fast broadband can boost the economic development while a slow one hinders it. Many countries such as USA, UK, China, Korea, Malaysia, South Africa, Japan, Australia, and Singapore have proposed their national broadband strategies and some are in the stages of rollout.
ZTE U-Highway Solution
A national broadband network uses the national telecommunication provider's network as the backbone, and other private networks, for example, government networks, enterprise networks, and education networks are supplemental. An NBN is deployed and managed in a centralized way by the government.
One of the solutions to enable a country to look at, develop and offer a National Broadband Network is found through ZTE and their U-Highway solution which is an end-to-end NBN solution supported by their strong R&D capabilities and product lineup. The solution includes three layers: terminal, pipe, and cloud. The terminal layer provides broadband connectivity, the cloud layer provides various services, and the pipe layer is the infrastructure connecting users to services.
- In the terminal layer, many user devices are available to connect people and things to the broadband network anytime and anywhere.
- In the cloud layer, abundant services are provided to make people’s lives easier and more entertaining, enhance productivity, stimulate innovation and business growth, and provide government services. Services can be government cloud service, personal cloud services, or industrial cloud services.
- In the pipe layer, fast, open, scalable, secure, and manageable network is built to meet the increasing demand for broadband. There are five modules: Uni-backhaul for the mobile backhaul network, Uni-NGA for the access network, Uni-metro for the metro network, Uni-backbone for backbone network, and Uni-BSS/OSS for billing and operation support system.
Highlights of the ZTE NBN Solution
With a backbone of up to 100G and an access network up to 10G, the large-capacity, highly scalable products create a future-proof network. Such a network can provide all services, including voice, video, and data and can meet bandwidth requirements in the coming five to ten years.
The U-Highway solution provides wired and wireless technologies to cover all access scenarios, from urban and suburban areas to rural areas. This bridges the geographic and digital divide.
The U-Highway solution has open content, channels and terminals. This allows resource sharing and fosters effective competition among players so that better services are provided.
The U-Highway solution has converged cloud, pipe, and terminal layers. Converged applications in the cloud give rise to new content. Converged wired, wireless, optical, copper all-IP networks in the pipe layer provide clear, unblocked channels for services. Converged devices in the terminal layer allow people to enjoy ICT services anytime and anywhere through a single device.
U-Highway Unified Backbone Network System has two parts: one is the transmission network and the other is the data network. Every part can carry different services to meet user needs. Data networks adopt IP switching technology and transmission networks generally are an optical switching network. The combination of these two networks reduce the number of core network nodes, optimizing the data stream.
The metro network is between the access network and the backbone network. It aggregates the traffic of the access network, bears multi-services and exchanges with the backbone network. The U-Highway Unified Metro Network System supports a 10G/40G/100G ring, integrated BMSG / DPI / Policy Server / Video caching technology. Its high reliability, high QoS, high QoE, precise synchronization, unified operation and maintenance meet the diverse needs of the metro network.
The U-highway Uni-NGA System realizes both wired access and wireless access. Wired access part adopts various access technology such as EPON, GPON, 10G EPON, 10G GPON, WDM PON, POTS, E1/T1, ADSL/2/2+, SHDSL, VDSL2, G.fast, basically any current telephony and communications standard.
It is built to suit various scenarios such as Fibre technologies and connectivity for FTTH, FTTO, FTTB, FTTC, FTTN and P2P.
The Wireless portion of the access network fully supports Short and Long range WiFi, 3G, 4G, Micro wave transmission, Long Term Evolution (LTE) and satellite communication to cover hot spots or remote areas such as rural areas without access to fixed line telecoms or broadband be they copper or fibre based technologies.
The U-highway Uni-BOSS System apply open architecture to meet the requirements of both business support and operation support from Service Provider or Retail Service Provider. As the management system of NBN, it realizes unified network device management, allocation of resources, trouble shouting, service billing, user management, data intelligence analysis and other functions.
- Access Network for Various Scenarios: Cable, copper and optical access for grown and green areas; WLAN for hot-spot coverage; satellite for remote coverage.
- End-to-End Bearer Network: 40G/100G large capability IP backbone; Unified multi-service iPTN aggregation; large capacity OTN aggregation; Carrier Ethernet Multi-service Metro-E Network.
- Unified BSS&OSS Management Platform: End-to-End Business Support Platform; Rapid Trouble diagnosing and locating; End-to-end Performance Detect and Customer Experience.
With the development of broadband service and All IP based services, there are more and more scenarios where Metro transport networks are using PTN+OTN. In this case, the interconnection, protection, and synchronization becomes the main problem that the operators need to consider
PTN+OTN Solution Overview
With this solution, the focus is on the demands and necessity of PTN+OTN as well as analysing the networking model, service provision and key functions.
PTN+OTN networking models are used either in small or large/medium-sized Metro networks respectively. The main difference between these two models lies in the large/medium-sized Metro network where E2E PTNs are deployed at the access, aggregation and core layers, and has a hierarchical structure, large capacity core and flexible GE dispatching; in small Metro network, E2E PTNs are deployed at the access and aggregation/core layers, and has a much simpler structure and efficient transport methods.
The two networking models can be further divided into initial and late networking models respectively. The main difference is that the line speed grows up, OTN sinks continually and control plane loads and so on.
Meet various requirements, and solve bottlenecks of service development
Meet various application requirements with different capacities of PTN and OTN equipment, and support the long-term service growth with PTN and OTN development planning.
Build a full-service bearer network/full-service operation with PTN+OTN
OTN should, on the one hand, work with PTN to transport high-value services (base station service and major VIP service), and on the other hand, bear public services (Household service and common VIP service) which are dominated by PON access services and uplink to OTN via OLT. Therefore, PTN+OTN is the main part in the full-service bearer network and will speed up the full-service deployment.
Smooth upgrade, orderly investment and low CAPEX
PTN+OTN meets the demands in the service development and network change by extending current network, improving line speed and capacity, and loading control plane. Then the operators can make the planning and development strategy according to the actual condition and upgrade the networks smoothly to save the long-term network investment.
Provide industry-leading time synchronization solution
The network can provide “1588v2 + Sync E” solution of the best time quality and accuracy.
Intelligent management and precise operation
PTN+OTN should be under unified management. Because PTN and OTN are different in their underlying technology, function, and maintenance frequency, it is suggested that EMS manages PTN and OTN respectively and NMS manages them uniformly to prevent frequent maintenance and upgrade of PTN from affecting the OTN. And precise operation is fulfilled through PTN hierarchical monitoring, OTN sectional monitoring, and TCM monitoring. Finally, network management system and other auxiliary tools can work together to implement intelligent construction and maintenance.