The conflicting demands of low cost of ownership and providing an excellent communications experience can only be met by highly efficient packet-switched technology. The good news, says Nokia Siemens Networks, is that carrier-grade packet switched solutions can now provide the quality required. Co-sponsored feature: Nokia Siemens Networks
Stephan Scholz: time is running out for circuit-switching
If the board of a communications service provider were to sit down now and write their requirements for a ‘dream’ network, what would they be looking for? Undoubtedly they would want a network that can carry high-bandwidth services such as Internet TV from ‘end to end’, meeting all customer expectations for service quality, choice of devices, freedom to roam between fixed and mobile networks, and so on.
For many communications services providers, there is pressure to make this dream a reality as fast as possible. Without networks that provide the experience demanded by their customers, it will be increasingly difficult in the next few years to generate a profitable level of revenues that can only come from running advanced services in a world where ‘all you can eat’ connectivity is taking hold.
The packet opportunity
“Time is running out for circuit-switched deployments as they cannot scale up to very high speeds, and boosting capacity inevitably requires a good deal more capital and operating costs, with long lead times to deliver often specialist solutions,” explains Stephan Scholz, CTO at Nokia Siemens Networks. “Emerging carrier-grade packet-switched solutions can now provide the necessary quality of service to handle growing volumes of multimedia and data traffic from a broad range of sophisticated new services.”
While the majority of fixed-line communications services providers in mature markets have already upgraded to packet switching, there are significant segments of the global communications services provider population that are still making the transition, such as fixed-line communications services providers in emerging markets, mobile communications services providers and enterprises with their own communication networks. “We recognise that the challenge for many communications services providers is how to make a smooth transition to packet-switched solutions, as most are not building a network from scratch,” says Scholz.
As he notes, the common packet standards, especially the internet protocol and ethernet, came from the information technology arena rather than the communications industry, and packet solutions can often fail to provide carrier-grade performance and reliability. “Best-effort data delivery is becoming not good enough,” adds Scholz. “For new, real time services such as voice over IP, IPTV and video on demand, communications services providers must carefully engineer their networks to achieve the necessary reliability, even if they have already been offering best effort packet-based services successfully for less demanding applications.”
At the same time, customer experience is becoming increasingly important for communications services providers. “With this in mind,” continues Scholz, “we have developed a blueprint, the ‘Network of One’, for transforming infrastructure, operations and business models to enable a truly individual communications experience, while maintaining high efficiency. Along with objectives such as convergent fixed-mobile services and one view of customer data, communications services providers will need to evolve their network architecture towards a simple flat, converged, IP-centric architecture for the most efficient traffic handling.”
How can communications services providers make this transformation?
Scholz sees three main options for moving to this carrier grade packet world. First, communications services providers can build a packet-switched overlay network in parallel with their existing infrastructure. Second, they can replace their current assets in favour of immediate, full implementation of a packet-switched network based on IP from the point of access to the core. And finally, they can reuse their existing assets by migrating their current networks to a mix of IP-based packet technology in the core and carrier-grade Ethernet for access and aggregation towards the edge of the network.
He adds: “Implementing packet technology will vary greatly depending on the type of network and market conditions – there will be different decisions and strategies for fixed, mobile, hybrid and enterprise networks. But some common themes are service connectivity at the most efficient transport layer, point and click provisioning of services, and unlimited capacity but with controllable characteristics such as latency and reliability.”
A particularly key technology in several markets is carrier ethernet transport. It is especially applicable in residential access, where services such as TV and video on demand will become huge consumers of bandwidth. The rollout of these real time services in multi-play bundles requires scalable and sustainable bandwidth and service quality.
“The enterprise business sector has already become a key market for carrier ethernet transport, and indeed has been the main early adopter,” says Scholz. “Forward thinking companies are extending their ethernet-collapse backbone LANs across metro and wide area networks in a seamless, cost effective fashion while maintaining native LAN speeds.” Much of this popularity is driven by migrating legacy TDM or IP-VPN services to roll out increasingly bandwidth hungry applications on ethernet.
Mobile backhaul is also becoming a major application for carrier ethernet transport. “Mobile broadband access could translate into a 100-fold increase on backhaul networks,” says Scholz. “Much infrastructure around the world is rooted in legacy leased line and TDM architecture that simply will not scale up to provide efficiently the transport requirements of next-generation networks – and that’s exposing a bottleneck in mobile backhaul.”
Next-generation mobile
Packet-based transport is also of course the key technology for next generation mobile networks in general, and carrier ethernet transport allows communications services providers to step into providing service level agreements that guarantee key performance indicators, such as dropped calls and mandatory transmission of synchronisation signals.
High-speed packet access (HSPA) and its various evolutions for mobile networks such as HSPA+ are now being widely deployed around the world and also offer a path to the huge bandwidth capacity of Long Term Evolution (LTE). HSPA can be deployed as an all-IP architecture where base stations are directly connected to IP based backhaul and then to the CSP’s edge routers.
“We have delivered IP-capable base stations to more than 130 operators and are currently seeing a lot of those operators asking us to migrate their transport networks to IP as the first step to LTE,” adds Scholz. “A case in point is at Bell Canada, where we have rolled out some of our most advanced solutions to enable an all-IP HSPA network through an end-to-end approach that includes our Flexi Base Station and radio network controller, direct tunnel enabled packet core, subscriber data management and the NetAct operations support system.”
Operational support and more
Common operational support for all parts of the network is a key point. “A centralised operation and administration management suite across the entire transport network can strongly improve the operational processes for reacting much faster to performance management, service provisioning and fault management issues,” he says. “With our NetActTM management solution, communications services providers can manage end-to-end network operations and can greatly simplify, consolidate and automate all transport domains across all platforms.”
Packet solutions come into play in other technologies in the network, such as with packet microwave radio for fast deployment of mobile backhaul, and photonic IP for scaling up to unrestricted IP capability over DWDM (dense wavelength division multiplexing) – towards 100 gigabits/s on one fibre pair which can help build terabit networks. “Multilayer optimisation of the various technologies is also critical to minimise cost for each service,” says Scholz.
Can IP and packet switching really deliver for communications services providers? “The proof can be seen in Munich at Nokia Siemens Networks’ ResIP [Resilient IP] solution centre, which we set up in partnership with Juniper Networks and Cisco,” says Scholz. “ResIP multiservice solutions are a result of long-lasting joint development work focused on validating, optimising and certifying IP solutions for voice, video, and data applications – end-to-end in aggregation, metro, edge and core.” GTB
For more information, please visit www.nokiasiemensnetworks.com/resip
Optimising networks – some key packet choices
- Leased line mobile backhaul evolution to self-build network
- Mobile backhaul evolution to packet
- IP/MPLS core with sufficient capacity
- IP/MPLS core with sufficient quality of service
- Multilayer optimisation with L2/L3 balancing for cost efficiency
- Connection oriented packet aggregation for scalability and quality of service
- Capacity and multicast capability for fixed access IPTV
- Service level agreements and quality of service for enterprise services, plus protocol transparency + Managed Extensibility Framework services