In 2012, service providers worldwide continued their aggressive rollout of LTE networks, with 105 operators in 48 countries having launched LTE commercially by the end of October. In total, over 350 network operators have invested or soon will invest in LTE. Overall, LTE is on a faster growth trajectory than any other mobile technology, projected to reach a billion connections in just over seven years (in 2017), whereas GSM took GSM twelve years to reach that milestone.

Driven by the number of subscribers and the exponential increase in video traffic, overall mobile data traffic is projected to grow 500x between 2010 and 2019, so the 25x performance increase provided by LTE compared to 3G is critical to meeting end users’ expectations.

In parallel with the growth in network deployments, however, cut-throat price competition among carriers has resulted in steadily declining ARPU (Average Revenue per User), despite on-going advances in the features and services being delivered to subscribers. This places extreme pressure on service providers both to improve the cost-performance of their networks and also to maximize their resource utilization.

Core network virtualization, which leverages concepts proven in cloud computing, has emerged as a key approach to maximizing network resource utilization and thereby minimizing network OPEX.

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In a virtualized core network, functions that were traditionally implemented in dedicated, stand-alone equipment are now instantiated as virtualized software running on generic hardware platforms. This enables service providers to achieve greater hardware efficiency and flexibility by dynamically allocating network resources to the most appropriate software applications. Network resources are allocated on-the-fly, according to traffic and service demands and with the capability to adapt easily to new traffic profiles as they arise. This provides high scalability and optimum hardware utilization.

The LiquidCore initiative from Nokia-Siemens Networks is an interesting example of this concept.

Core network virtualization provides important business-level benefits for service providers, including:

  • Reduced CAPEX thanks to the use of standard generic hardware platforms;
  • Reduced OPEX through improved resource utilization;
  • Greater network flexibility to dynamically provide network resources where and when needed;
  • Improved ARPU through the accelerated deployment of high-value features and services;
  • Increased subscriber retention;
  • Improved network monetization.

The recently-announced Network Functions Virtualisation initiative was launched by leading service providers and Telecom Equipment Manufacturers (TEMs), with the goal of establishing industry-wide standards around key aspects of core network virtualization. Strong attendance at the group’s initial working meeting, held in France last week, indicates the high importance placed on this topic by companies at all levels of the supply chain.

But there’s a problem. From the perspective of the hardware platforms used for core network virtualization, industry-standard software hypervisors severely constrain the performance of network I/O in virtualized environments, so that virtualized networking equipment delivers only a fraction of the networking performance achieved by physical equipment. This significantly limits the use of virtualization in network-intensive applications such as LTE infrastructure.

Luckily, there’s a solution. At 6WIND, we recognized this hypervisor performance problem and enhanced the 6WINDGate™ software, already widely deployed in physical LTE networking equipment, to deliver significant performance improvements in virtualized environments as well (details here). The 6WINDGate software has now become a key enabler for the virtualization of mobile network functions. We are working with several innovative TEMs on such programs, thereby enabling service providers to achieve the level of networking performance that is critical for virtualizing mobile core functions at an acceptable cost.

All indications are that core network virtualization will become increasingly deployed in LTE infrastructure, as service providers achieve tangible business benefits leverage the concept to maximize the ROI of their networks.

What’s your opinion on the network virtualization trend in LTE? What are the barriers to adoption of this concept? Are there key features and/or services that will accelerate deployments?