 | Issue: | Africa and the Middle East 2005 |
| Article no.: | 12 | |
| Topic: | Broadband in Africa: getting it right | |
| Author: | Amnon Unger | |
| Title: | CEO and President | |
| Organisation: | Teledata Networks | |
| PDF size: | 52KB |
About author
Amnon Unger is the CEO and President of Teledata Networks. Previously, Mr Unger served as the Vice President of R&D in the wireline division of ADC and as a Country General Manager for ADC. Mr Unger has more than 25 years of experience in the telecommunications industry, championing very large development projects. Mr Unger holds an MSc degree in Electrical and Electronic Engineering.
Article abstract
Broadband deployment in Africa is low and much of its infrastructure is obsolescent. African telecom operators, leveraging experience of operators in other regions, can plan the expansion of their access network architecture so advanced services can be implemented with minimal additional investment. The major trends affecting network architecture are triple play services, which require access network architectures based on FTTX (fibre-to-the-curb/node/home/building), and migration to NGN, which requires that the access nodes deployed be upgradeable to VoIP access gateways.
Full Article
The telecommunications market is recuperating from the downturn of recent years. Telecom service providers have resumed investing in their network development. However, they are spending in a much more cautious manner, justifying all expenses by either the reduction in operating costs they bring or by the new revenue streams they will generate. Two of the most noticeable trends arising out of this new mindset and influencing network architecture, are the proliferation of broadband service availability – making triple play services (video, data and voice) possible, and the migration to NGN (Next Generation Networks). Broadband and the information age Broadband has been affecting the lives of millions. It has changed the way people communicate, do business or even spend their free time. Broadband availability has been one of the catalysts driving social and economic growth. The worldwide broadband subscriber base has already surpassed the 150 million mark, with broadband over DSL being the leading technology used. Broadband service prices have been dramatically reduced in markets characterized by a high level of competition between service providers, making this technology affordable to all customers. However in markets that lack a high level of competition, either from alternative carriers or alternative technologies (ie CATV, or cable TV, operators and wireless service providers), prices tend to remain at a high level, affordable only to a small segment of the population. Until recently the battlefield between the two main broadband technologies – DSL over copper and broadband over CATV – has been situated mainly in the data services arena. Despite the competition, each still maintained leadership in its core service – the Telecom operators in voice and the CATV operators in video. However, recent developments in regulation as well as in technology have enabled CATV operators to offer their customers a complete bundle that includes all three services – video, data and voice – thus threatening the telecom operators’ main source of revenue, voice. Telecom operators have been forced to develop a counter offer in order to avoid customer loss and are offering a competing bundle of their own that includes voice, data and video. This battle between service providers has favoured the end customers, driving service prices down and introducing new technologies and services not available before. One such recent example is IPTV (Internet Protocol TV), which enables service providers to offer more than just “plain vanilla” broadband. Rather than offering a broadband pipe, priced according to bandwidth, the operator can offer his customers a variety of premium services such as VoD (Video on Demand), PVR (Personal Video Recorder), interactive content, etc. Service evolution and access architecture In developed countries, the new infrastructure that supports broadband services has been built mostly as an overlay to the existing voice network, as voice teledensity is high and there is no growth in demand for POTS (Plain Old Telephone Service). Initial deployments have been usually based on DSLAMs (Digital Subscriber Line Access Multiplexer) located in central offices, providing best effort broadband pipes to the subscribers. DSL (Digital Subscriber Line) technology is highly dependant on distance between the two end points utilising the technology, as well as additional parameters such as the copper loop’s quality. With DSL, the longer the distance from the central office, the lower the bandwidth that can be delivered to the user. Emergence of new services over broadband, especially video, has driven the need to deliver much higher bandwidth to the customer. Although velocities of one-half to one-and-a-half megabits per second and best-effort service is sufficient in most cases for Internet surfing and related applications, there is a need for 10 Mbps-20 Mbps bandwidth per customer with guaranteed QoS (Quality of Service) for real time applications such as video viewing or VoIP. The development of new DSL standards, such as ADSL2+ or VDSL2, has brought technological enhancements that enable higher bandwidth compared to existing standards. However, these enhancements alone are not sufficient as the new standards can only provide this high bandwidth over short distances, so there is a need to shorten the “last mile” loop and deploy access equipment outside the central offices, closer to the customers. As a result, operators are extensively using hybrid fibre/copper access architecture, pushing fibre deeper into their access network and shortening the copper loops. Deployment of remote access elements, using architecture based on FTTC (Fibre-To-The-Curb), FTTN (Fibre-To-The-Node), FTTB (Fibre-To-The-Building), or FTTH (Fibre-To-The-Home) is widely used. Adapting triple play access architecture for Africa Fixed voice lines are still uncommon in many parts of Africa, the average penetration rate on the continent is only three per cent, so there is still high demand for basic voice services. Though mobile penetration is increasing rapidly, it cannot fully replace fixed voice services in terms of coverage and pricing. Broadband development is just emerging in Africa; penetration rates in most areas are still low, and service is limited to best-effort quality and bandwidth. However, it is forecasted to grow rapidly as most of the market is still untapped. The current requirements for voice and broadband services, combined with future broadband evolution requirements – estimated in accordance with broadband usage in other regions around the globe – can let African telecom operators plan their access infrastructure taking into account the following considerations: √ Planning a hybrid fibre/copper access infrastructure calls for the evaluation of alternative access architectures, such as FTTC or FTTB, according to their cost effectiveness in local deployment scenarios; √ Flexible multi-service access nodes, capable of supporting a combination of voice and broadband services, are needed. These platforms should include attributes such as high scalability to cover areas of different sizes and population densities, the ability to withstand harsh outdoor environmental conditions, and a small “footprint” to fit into tight spaces; √ Planning the access network should, generally speaking, be based on each access node serving relatively small areas, since the need to provide higher bandwidth to each subscriber means the local DSL equipment must be located closer to the end user. The challenge – migration to NGN Migration to Next Generation Networks, or NGN – packet-based networks able to handle both traditional voice and added-value services – has become a key factor in telecom operators’ strategy. Although this may vary according to specific market and operator conditions, the reasons include: √ The cost savings that can be realised by using the new IP optimised technologies, standards and components that are less expensive compared to legacy voice-networks; √ The reduction in operational maintenance and management costs made possible by using the same network for both voice and data; √ The competitive pressure to offer new, added-value services that cannot be offered using legacy voice networks, to hold existing customers and increase ARPU (Average Revenue per User); √ The obsolescence of existing voice switches is expected to peak in the coming years and will drive the need for an alternative solution for voice. Migration to NGN is an evolution rather than a revolution. Class 4 tandem switch (network switches that, in general, connect between carriers) replacement is ongoing; a major part of international voice traffic is already going over the IP network. Class 5 replacement, the replacement of local access switches, is a much more complicated process, as it requires connection to the end customers and preservation of all existing supplemental voice services (caller ID, call forwarding, waiting call, etc.). Operators have been testing VoIP in the local network for sometime and some commercial deployments have been made, though mostly over broadband connections, requiring the end users to add an IP phone or a residential gateway. Although mass market VoIP deployment has yet to come, it is expected to accelerate in the coming years. Mass market VoIP deployment requires the operator to implement a wholly new infrastructure at the switching layer. This entails replacing existing PSTN (Public Switched Telephone Network) switches with soft switches (software – as opposed to hardware – controlled switching), adding media and signalling gateways to connect to other related networks and deploying appropriate management and OSS (Operations Support Systems) software for the new environment. One of the major challenges in a full-scale NGN deployment is migration of the access layer, and the customers, to VoIP. Although telecom operators are increasingly replacing their existing switching infrastructure with a packet-based NGN one, most customers will probably keep their regular “black phone” for voice. Only a small portion of the customers will be willing, or able, to invest in having VoIP enabled equipment – a broadband line and IP Phone or residential gateway – at their home. This means that when operators upgrade their core networks to IP-based NGNs, they must plan a “VoIP-ready” customer access network that can be easily, and with minimal cost, be converted from regular voice access to VoIP. Telecom operators in Africa, leveraging the experience of operators who have deployed new services in other regions, can plan their access network architecture so that advanced services can be implemented with minimal additional investment. The two major trends affecting network architecture are triple play services – which call for an access network architecture based on FTTX (fibre-to-the-curb/node/home/building) and migration to NGN – which requires that the access nodes deployed be easily upgradeable to VoIP access gateways. This access network should be adapted to each region’s specific requirements. Smart planning of the access network to support advanced services will minimise the need for future investment and, as well, speed the implementation and time to market of these services.
