Bell Labs Looks to Nature in Designing Smart Networks

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Wednesday, September 1, 2010

From a consumer’s perspective, the entire world is at their fingertips and available through their phones, PDAs or laptops. It’s as if any piece of information or content can be created, sent or received instantaneously. Videos are uploaded or downloaded with a single touch and images and files shared seamlessly. Any call or text is effortlessly completed with a touch or two on their keypad and their “connectedness” to family, friends or business associates is assured.

But for the telecom service provider, delivering this high level of service and quality of experience is anything but effortless. Today’s service providers manage networks that require tremendous amounts of hands-on involvement by human operators. While current OSS’s and BSS’s provide a measure of automation for some portions of a service provider’s operations, today’s network management remains mostly an ad hoc effort. All the elaborate processes and efforts to plan, configure, operate, manage, maintain and tune network systems – with human involvement – accounts for a significant fraction of an service providers annual operating expenses.

Bell Labs Approach

Some of today’s networks aren’t fully optimized for capacity or performance and with the ramping increase in broadband traffic, operating costs continue to soar. The forecast is that the pace of automation is being outstripped by the growth of the network scale, capacity and capability. To support continuous broadband traffic growth and new broadband service launches, telecom service providers need flexible, scalable and efficient solutions that make network build-out, configuration and service innovation and delivery simpler, faster, more automated and less costly.  At the core of the network, these solutions must cost effectively contend with more bandwidth–intensive applications and meet end-user quality of service expectations.

To breakout of incremental improvements to network management, Bell Labs research is looking for solutions that increase efficiencies and reduce operating expenses by orders of magnitude. Researchers look across several management layers - service, network, element and network element - to determine where the greatest efficiencies can be achieved. Rather than enhance or add new management policies and processes that would add complexity and increase human oversight - and additional cost – to network management, it seems that the opposite approach may provide a solution. That is, allow the network to manage itself.

 

“The scale and complexity of modern communication systems and networks, and the progressively decentralized nature of their ownership are strong reasons to look at self-organization and self-optimization as possible models for management and control of these highly complex systems. Complexity here is not merely a computational and transport challenge that could be overcome through acquisition of vast amount of computational, switching and transmission resources, it is the diversity of applications, volume of connections, geographic spread of users, localized ownership of the network and ‘connectivity, anytime, anywhere’ with ever increasing bandwidth that make the underlying systems challenging to manage in traditional ways.  Even a 10% reduction in network OpEx, easily expected from a self-optimized or Self-X approach to network operations, translates to $10Bs of saving annually for operators across the globe.”

- Iraj Saniee, Head, Math of Networks and Communications Department


The Natural World of Self-Optimizing Networks

One novel approach to machine to machine interaction in future networks is to adapt and leverage the control principles found in nature. Spontaneous magnetization, crystallization, lasers and superconductivity are examples of self-organization in physics where cohesive behavior emerges from initial disorder. In self-assembly and auto-catalytic networks in chemistry, molecules organize themselves in well-ordered arrangements without external action and in biology we observe highly complex coordinated action as in the folding of proteins, homeostasis and flocking.  An example from physiology that is even closer to networks is the self-optimizing and self-management phenomenon found in the human body - the autonomic nervous system (ANS).   The ANS is a regulatory branch of a person’s central nervous system that helps them automatically adapt to changes in their environment. The ANS helps regulate the heart, breathing, temperature, blood vessels' size and blood pressure, bronchial diameter (and thus air flow) in the lungs, stomach, intestine and salivary glands, etc. All of this is achieved automatically without direct conscious control. Blood is pumped, breaths are taken and food is digested and we never think twice about it.

Communications networks can benefit in a similar manner, if the piece-parts of the network - routers, switches, base stations, and numerous other less-known elements all perform basic network operations – resource management, traffic management, fault management and recovery, service upgrades, security and others without resorting to human operator.  For example, instead of pre-planned partitioning of the wireless spectrum as it was done for GSM (and may be needed for LTE), could base-stations self-determine their portion of the spectrum as needed based on actual loads and negotiate resources with their neighbors dynamically?  It turns out that there are formal ways to perform these tasks with neither massive signaling for coordination nor reliance on human operators, just as in the above examples from nature.

Bell Labs Looks to Nature

Iraj Saniee has been leading an effort within Bell Labs Research known as Self-X to derive formal mechanisms to enable self-organizing networks.  Pulling in distinct efforts and appropriate expertise from across Bell Labs (including Murray Hill, Villarceaux, Stuttgart and Dublin), this team has been able to define a series of solutions that progressively improve self-sufficiency of networks.  Formal techniques, such as gradient methods, stochastic approximation, annealing randomization and particle systems, are leveraged and combined with engineering insight to devise novel Self-X algorithms with little communication overhead. 

The Impact of an Automatic, Self-Optimizing Network

In a cellular network for example, having fixed or static frequency assignment works well when the load on the network is uniform.  However, such “averaged out” load hardly ever occurs in practice. There are load fluctuations all the time, which is better suited to dynamic spectrum allocation.  But even more so, when a portion of the network becomes overloaded due to an unexpected event (e.g. a sporting event), or excessive load due to a new technology (e.g. a cluster of wireless, high bandwidth on-line gaming activity) there is no capability to automatically adjust to conditions that are overwhelming the network. The result is degraded or suspended service. To hedge against these, more spectrum and capacity needs to be allocated upfront than needed, whereas a self-stabilizing dynamic allocation would allow the cellular network to optimize spectrum by redistributing the load and reconfiguring bandwidth and power allocation per cell.

Similar examples arise in parameter tuning in wireless networks, bandwidth reservation in broadband access, and learning of dynamic configurations in wireline networks.  Decentralized control and a self-learning solutions that operate throughout the network – with little intra-network signaling – allows for higher level of flexibility and adaptability to meet to broadband traffic growth and end-user QoS demands while keeping operator costs in check.

“One can look at the handoff threshold in cellular networks as a function that could be improved through an automated approach. Handoff threshholds are currently fixed to predetermined operator-set levels but with a Self-X solution, the cells in the wireless network would have added functionality to learn and adapt to traffic and load to automatically and dynamically set the threshold in order to minimize call drops. This then becomes an automated, hands-off task handled within the operator’s network and improves the end-users experience by delivering uninterrupted service.  

                -  Iraj Saniee, Head, Math of Networks and Communications Department

According to consumer trends, it is a natural development for end-users in the future to have even higher expectations regarding seamless delivery and QoS for their ever increasing high-bandwidth services. Through the examples provided by nature, Bell Lab’s approach in developing this novel solution for a self-optimizing network - Self-X – will help to not only meet their customer expectations by automating and improving overall network operations, but will significantly reduce their addressable OpEx as well.

Many of the potential advantages of Self-X are already anticipated by industry standards.  The 3GPP SON committee has been developing standards for signaling and data between network elements in anticipation of self-organizing in wireless LTE networks.  However, challenges remain to demonstrate to traditional network managers that a Self-X type of approach is effective and practical.  The expectation is that the LTE standard will facilitate the introduction of Self-X in communication and telecommunications in the next 2-3 years.