 | Issue: | North America 2011 |
| Article no.: | 7 | |
| Topic: | Converged packet backhaul | |
| Author: | Alan Solheim | |
| Title: | VP of Corporate Development | |
| Organisation: | DragonWave Inc. | |
| PDF size: | 271KB |
About author
Dr Alan Solheim is the Vice-President of Corporate Development at DragonWave Inc.; he has more than 25 years of telecommunications industry experience. Previously, Dr Solheim was VP of Product Management and responsible for the introduction of DragonWave’s packet microwave product line. Prior to joining DragonWave, Dr Solheim was Chief Technology Officer at Innovance Networks, a reconfigurable optical networking start-up. Dr Solheim also held various roles at Nortel Networks, most recently as VP responsible for market strategy in the metro transport group. Dr Solheim worked on six generations of fibre optic transmission systems, and was the system design authority for Nortel’s OC-192 program. Dr Solheim was the principal or co-author of over 50 patents. Dr Solheim also writes a bi-monthly column “The Middle Mile” for Internet Telephony, and has numerous papers in industry journals such as European Communications, Mobile Europe and Converge Digest. Dr Solheim has acted on a variety of industry and conference committees such as 4G World, IWPC, CTIA, WCA, GITEX and numerous Webinars. Dr Alan Solheim holds a PhD in Electrical Engineering from University of Waterloo.
Article abstract
Demand for mobile services has never been greater, but existing mobile networks need updating to handle the added traffic. Hybrid systems handle legacy TDM (time division multiplex) and Ethernet, but are costly. Converged packet solutions offer both TDM and Ethernet on a single flat-IP network. The economic benefits of converged packet networks are significant; the CAPEX savings, though, are dwarfed by the simpler network’s OPEX savings and the enhanced revenue opportunities available to an operator with a scalable, responsive network.
Full Article
Converged packet backhaul by Dr. Alan Solheim, Vice-President, Corporate Development, DragonWave Inc. The rapid adoption of smart phones, tablet computers and mobile broadband enabled laptops has had a profound impact on the way we work, communicate and interact socially. While the benefits and drawbacks of an always-connected lifestyle can be debated, there is little doubt that the general public will not be willing to give up their new appliances any time soon. If anything, the demand for more/better/faster is escalating. What impact has all of this had on the underlying telecom network? On wired networks, IP traffic overtook circuit-switched voice traffic nine years ago. Mobile networks have been traditionally more weighted to voice calls however recently the same milestone took place within the wireless domain. In early 2010, data traffic accounted for slightly more than 50 per cent of all traffic carried over mobile networks. While this event was certainly not unexpected, it did arrive several years sooner than many had expected. This was due in large part to the unmitigated success of the iPhone, which opened the door for a new breed of mobile device and spurred a rapid transformation in the profile of a typical mobile user. Figure 1 illustrates the rapid growth of data traffic – driven in large part by a surge in video traffic over mobile networks. Video traffic is growing at an annual rate of 130 per cent, representing 66 per cent of the mobile traffic mix by 2014. The unprecedented growth (shown in Figure 1) translates to good and bad news for mobile operators. One on hand, demand for their mobile services has never been greater, on the other hand, existing mobile networks are driven well beyond their intended capacity. In addition, the revenue growth for mobile services unfortunately does not match the exponential growth in data – meaning that cost per bit must drop dramatically if future mobile services are to be profitable. Moving to the next generation of mobile access networks is an important step in achieving this goal, but operators are then faced with the question of how best to backhaul TDM traffic on the existing network, as they evolve to packet-based 3G and 4G networks – all while simplifying their operations and reducing their total cost of ownership. Choosing backhaul solutions To ensure a smooth transition to packet-based mobile networks, it is essential that operators select a backhaul solution that will meet near-term requirements without compromising the future performance of their network. In addition to supporting this evolution, the backhaul network should be viewed as a strategic asset which has a critical role in unlocking advanced applications and services while providing operators with several important competitive advantages including: • Rapid time to market with new services; • Flexible on-demand scalability to eliminate stranded capital and deliver a future-proof network; • Advanced Quality of Service (QoS) support; • Low latency; • Carrier-grade availability; • Simple operation and self-healing architecture; and • Lowest total cost of ownership Hybrid backhaul Hybrid systems offer the benefit of carrying TDM (Time Division Multiplex) and Ethernet in their native forms. This is done either by leaving the existing TDM backhaul solution in place and overlaying an Ethernet backhaul solution, or by deploying new backhaul equipment that can handle both TDM and Ethernet in their native forms. This allows service providers to continue to support existing TDM traffic while simultaneously expanding their capacity for data traffic, but comes at a significant operational cost. Figure 2: A Hybrid microwave architecture with parallel TDM and Ethernet networks. The downside to supporting TDM and packet natively is the need to deploy, operate and maintain two parallel networks. As illustrated in Figure 2 above, this involves having both Ethernet and TDM infrastructure, including TDM switching equipment throughout the network. Beyond the complex intra-office cabling and congested racks, this approach also requires separate management and provisioning platforms, which introduces significant operational and management complexity and cost. If leased E1 or T1 circuits originally handled TDM backhaul, this hybrid approach has the added burden of paying ongoing lease charges to the local wireline carrier – who may well be affiliated with the wireless operator’s competition. As TDM becomes a significantly smaller piece of the mobile traffic pie, operators with hybrid solutions will eventually look to simplify their operations in order to achieve a fully optimized flat-IP network. In other words, many hybrid solutions risk being a barrier to most operators’ ultimate end-goal. Let’s look at one technology in particular: Microwave has been the technology of choice for the majority of mobile backhaul on a global basis. Despite the popularity of hybrid microwave systems when TDM was still the predominant type of mobile network traffic, the debate surrounding the adoption of hybrid systems vs. pure packet or converged packet microwave systems, is essentially over; the market for hybrid systems has been in decline since early 2010 , while the market for packet-based microwave systems has been accelerating . Converged packet backhaul Offering both TDM and Ethernet interfaces, using converged packet solutions, is another way to solve the same problem. The difference, compared to conventional hybrid systems, is that rather than transporting parallel TDM and Ethernet networks, these products converge all data and voice traffic, creating a single flat-IP network. Figure 3: A converged packet microwave architecture. Additionally, unlike conventional hybrid systems, which are built for legacy TDM traffic, but have the capability to transport Ethernet, converged packet microwave system are engineered from the ground up as packet-networks, but fully support TDM traffic to enable a smooth transition to a flat-IP, uncompromised, end-state network. One of the primary advantages of a converged backhaul network is the reduction of network elements; they do not require extensive intra-office connections or TDM switching throughout the network. The economic benefit of a simplified converged packet network can be significant, but the exact savings are dependent on each operator’s particular starting point. The capital expense savings, however large they may be, however are dwarfed by the operating expense savings of a simpler network and the enhanced revenue opportunities available to an operator with a scalable, responsive network. ________________________ Today, any backhaul solution deployed today must deliver the capacity, scalability and performance needed for advanced applications well into the future. Looking at the rapidly evolving traffic mix on mobile networks, as well as the shift to 3G and 4G networks, it is clear that the ultimate goal for service providers is to have a single, reliable, and unified packet-based network that will support both legacy and emerging services. Today’s converged packet backhaul solutions offer operators the simplest and most cost effective approach to achieving this goal. Positioned for the future, these systems deliver a packet-based architecture that still provides complete support for TDM circuits, while providing the following key benefits: • Lower capital expenditures, maintenance, and management costs; • Simple migration to the next-generation network without compromising legacy traffic; • Higher network utilization, lowering costs of transmission; • Implementation of strategic investments in IP/MPLS and Ethernet infrastructures – freeing; resources that are currently invested in maintaining legacy infrastructure; • Advanced synchronization support and clock recovery mechanisms; and • A flexible future-proof architecture This approach enables operators to evolve their network gradually over time as their traffic and service mix changes, arriving at an uncompromised end-state network optimized for next-generation applications and services.
