 | Issue: | Europe I 2008 |
| Article no.: | 16 | |
| Topic: | Change is in the air | |
| Author: | Ira Palti | |
| Title: | President and CEO | |
| Organisation: | Ceragon Networks | |
| PDF size: | 374KB |
About author
Ira Palti is the President and CEO of Ceragon Networks; he has over 20 years of experience in the hi-tech and telecommunications industry. Prior to joining Ceragon, Mr Palti was CEO of Seabridge Ltd, a Siemens company. Before taking over at Seabridge, Mr Palti was the COO of VocalTec Communications Ltd, responsible for sales, marketing, customer support and product development. Among the positions he held before joining VocalTec was founder of Rosh Intelligent Systems, a company providing software maintenance and artificial intelligence diagnostic solutions; it was one of the first start-ups in Israel.
Article abstract
Mobile broadband for video, music mobile TV Internet access and the like, are putting increasing pressure on the networks. The pressure is not only on the access network but, as well, upon the backhaul network that connects the towers to the core network. Three factors – capacity shift caused by high bandwidth services, the shift to 3G mobile broadband or technology shift and the need for a low-cost, high capacity, physical backhaul carrier – are contributing to the backhaul problem.
Full Article
Broadband’s in the air; it’s easy to spot. Our cell phones are becoming miniature portable multimedia devices while dozens of new services – web browsing, music downloading, video and mobile TV and more – are becoming available. We can share pictures, clips, emails and ideas with anyone from virtually anywhere – providing, of course, we have the right handset and are lucky enough to be connected to a network with sufficient bandwidth. Much has been said about access bandwidth in cellular networks, but recently more attention is being given to another segment of the operators’ network: backhaul. Backhaul is the part of the network that connects the access network, for example cellular towers, with the operator’s core network. Until recently, cell towers were connected to low bit-rate ‘pipes’ – whether wired or wireless – with typical speeds of 5Mbps per base-station. With mobile TV and other bandwidth hungry multimedia services gaining popularity, that’s about to change. Backhaul for mobile networks Regardless of the air-interface (UMTS, HSPA today, EV-DO, WIMAX or LTE tomorrow) their broadband access networks use, operators are seeking to overhaul their backhaul. There are three major trends: capacity shift, technology shift and physical medium shift. Capacity shift refers to the introduction of high bandwidth services that call for higher capacity backhaul. The current low-capacity connections are being upgraded and traffic on high capacity connections is growing. The shift in technology, the move to newer 3G, or higher, radio-access networks will require IP backhaul networks to handle the higher traffic rates. There will also have to be a shift in the physical medium used by backhaul networks – copper lines cannot handle the demands of increased broadband usage. Fibre is expensive and difficult to rollout in many areas, so carriers are tending towards wireless backhaul solutions. Feeding the network Some of us still remember when they replaced their dial-up modem with a high speed DSL or cable modem. That was the same day we swore we’d never go back to dial-up again. It’s happening again now to those early adopters who traded their old handset for a new 3/3.5G phone. Operators are quickly scaling their access networks to handle the high-bandwidth traffic generated by these devices. Yet if they fail to invest in high-capacity backhaul solutions as well, their next-generation networks will soon be useless due to backhaul bottlenecks. There are few things than annoy communication-dependant people as much as a high-end device that cannot perform due to network congestion. Apple’s celebrated iPhone, for example, and future iPhone-like devices, will drive cellular data traffic to higher peaks and force operators to upgrade their infrastructure to support the high bandwidth demands. The need for additional bandwidth is clear today although only few users own an iPhone. It will get worse in the near future if more people have an iPhone, or iPhone-like handset, than those who don’t! The proliferation of high-end handsets will have a tremendous impact on backhaul networks. Today, 3/3.5G phones make up only about ten per cent of the handsets in use, yet in some parts of the world mobile networks are already straining to support data-rich applications and services. Imagine what will happen in four to five years when high-end handsets will account for 25 per cent of the handsets. New data services force networks to deal with huge amounts of data packets; they require bigger, more efficient ‘pipes’. Video and VoIP applications will also force mobile backhaul systems to deal with delay sensitive, bandwidth-dedicated, high-priority services that must be handled differently than other traffic. The network’s need for bandwidth is well-known. Cellular operators worldwide are examining ways to enhance their backhaul capacity. According to market research group Visant Strategies, most cellular base stations today are ‘fed’ by backhaul links that provide up to10Mbps. By 2012, however, the majority of base stations will require higher capacity – up to 100 Mbps per base-station. IP days Increasing capacity raises another challenge for mobile operators, since the cost-per-bit grows in direct proportion with the growth in capacity. No less troubling is the erosion in revenue per transported bit, which will worsen with new media-rich services. Decoupling cost and capacity is driving an industry-wide shift towards all-IP networks. There are many reasons why operators migrate their networks to IP. Today’s value-added services are based on IP and IP can also handle data traffic more efficiently than legacy technologies. Going ‘all-IP’ also helps operators reduce their operational expenses. What operators save on OPEX, they can place on their balance sheet or roll back to their customers in the form of more favourable service packages and more competitive pricing. The shift towards IP for mobile access has been anticipated since the debut of 2.5G data services in the mid-1990s, but it’s finally happening now to handle growing high speed data traffic. The all-IP networks of the future – from access, to backhaul to the core – will support more services more cost effectively and will help accelerate the penetration of high-end handsets and value-added services beyond the early-adaptors phase. The wireless behind wireless Selecting the physical medium for mobile traffic backhaul has a tremendous effect on both the speed and quality of the service a mobile operator can provide – and upon the success of its business model as well. Investing in low-cost, low-capacity solutions may be tempting, but insufficient bandwidth creates bottlenecks as data traffic increases, rendering some, if not all, services unusable. A high-bandwidth technology that is expensive to deploy and maintain will lead to high operating and capital expense. Operators will then have to choose between two bad options: increase service costs and risk losing customers to the competition; or, keep prices down and risk losing money on their investments. The right technology is then one that supports high data rates and offers a quick and positive return on investment. Copper T1/E1 lines were the traditional backhaul medium of choice. Typically, T1/E1 lines can be leased for several hundred dollars per month although in some parts of the world it can cost several thousand dollars per month. Since T1/E1s handle only 1.5Mbps to 2Mbps, operators often use two or four T1/E1s per base-station to increase their backhaul capacity to 3 and 6 Mbps – still far short of the bandwidth needed by future networks. Deploying additional copper lines to increase capacity is uneconomical; it would take tens of T1/E1 connections to support the tens or even hundreds of Mbps required. Fibre offers virtually unlimited capacity and is a wonderful solution where it exists. Yet the costs of deploying new fibre can be prohibitive. The cost of deploying one mile of fibre in an urban environment can run from US$250k up to US$1 million. In addition, fibre is labour-intensive and slow to deploy. Laying fibre to serve remote base stations, in rural areas, along highways and railways etc., will drive costs and deployment time even higher. The alternative currently sought by many operators is wireless point-to-point microwave technology. Wireless links can be deployed quickly and – where limited or no infrastructure is in place – they eliminate the costs associated with digging up the ground to lay fibre or copper. A single link can set up in a matter of hours and bridge over tens of kilometres/miles – as long as a line of sight is maintained. Supporting up to 900 Mbps over a single radio channel with wireless microwave systems, brings fibre-like speeds at a fraction of the cost. The wireless behind wireless – a cell tower with high-capacity microwave antennas Change is in the air The iPhone experience, the proliferation of high-end cellular 3G/3.5G handsets, and the growth of bandwidth-hungry services, have changed the cellular market. Mobile operators now have to adapt their networks to meet the growing volumes of data traffic. Upgrading and expanding their networks, operators are also faced with the challenge of decoupling costs and bandwidth. The three major industry trends – capacity shift, technology shift and physical medium shift – are all aimed at making mobile communication better, easier to operate and use, and, yes, more affordable. High speed IP-based technologies are already being used in the access segment of the network and are quickly becoming more common in backhaul applications as well. The move towards wireless IP solutions in the backhaul would complete the puzzle and allow operators to speed up their network expansion and benefit from further OPEX reduction. More efficient networks that carry a wide range of value-added services at affordable prices are good news for operators and users alike.
