When I first wrote about smart cities for this blog back in 2013, the concept was still very much just that – a concept.

Fast forward to today and nearly every city, both large and small, is developing and perhaps even implementing plans to make their cities smarter.

Over these few years, the key drivers and motivations for moving towards a smart city environment have remained unchanged. For many cities, the driver is economic in nature – creating new business models or perhaps cost efficiency; for others it is related to reducing energy consumption and, finally, the driver may be the need to improve the quality of life in a city environment through better services. Essentially, most smart city efforts are simply about making cities work better.

The area with the most change has been the applications being proposed and/or supported for smart cities – particularly driven by advances in the internet of things (IoT), but also the shift in usage patterns and the unabated growth in mobility. 

As shown below, there are a variety of categories and associated applications being developed and deployed by smart cities. These diverse sets of applications each have their own unique requirements, but, in order for a city to truly become more efficient, it will require a robust ICT infrastructure. At its foundation is an all-IP network core network that can integrate wired and wireless technologies to create a converged infrastructure in support of high-speed internet services, as well as monitoring and sensor technologies that can help enable advanced services and applications while helping to achieve carbon-neutral footprints.

SDN and NFV: Key Enablers to Making Cities Smart

Most cities have multiple disparate communications networks in support of the varying requirements of different agencies, such as government, public safety, etc. Often this network of networks is composed of proprietary solutions that are costly to maintain and whose technology lifecycles continue to shorten, accelerating obsolescence. In order for a city to become truly “smart” and fully leverage its assets and capabilities, these networks must work in a converged fashion offering seamless connectivity. 

By unlocking the chains tied to vendor-specific equipment, smart cities can greatly benefit from the use of commercial off-the-shelf components and the implementation of virtualization technologies such as software-defined networking (SDN) and network functions virtualization (NFV). By embracing virtualization within its networks, a city will be able to build a more flexible architecture that is programmable and automated, elastic and dynamic, as well as open and interoperable.

SDN offers a level of network programmability that enables network managers to control and manage all of the network services via the control plane. By creating “network slices”, network resources can be customized and optimized for different service deployments, allowing a single physical network to support a wide range of services. For example, in an emergency situation, SDN controllers have the ability to redirect bandwidth needs within the network to ensure network uptime and higher quality transmission. 

NFV allows a network function to be programmed via software instead of by a physical piece of hardware. In addition, network functions can be executed independently of location, allowing the placement of functions to support different requirements, such as latency. This offers a level of agility and the ability to process information and take action in real-time. While SDN redirects resources, NFV allows for real-time scalability of resources through virtualization and enables the scalability of hardware needed to accomplish this.

IoT and machine to machine (M2M) will also play key roles in the evolution of the smart city. M2M is the technology that establishes intelligent communication between IoT devices, providing online data gathering, remote control and process automation. M2M technology can report on the status of IoT devices and sensors being monitored via the internet and enable intelligent, real-time decision-making for an array of services, such as traffic lights, parking and energy usage.

Bristol Is Open: An Open Programmable City

In the UK city of Bristol, the University of Bristol and Bristol City Council, through a joint venture, have created Bristol is Open, the first open programmable city. The network includes optical, wireless, radio frequency sensor mesh and computing resources in order to provide an open and programmable communications platform.  Open data access is a key part of Bristol's smart city project, allowing residents, researchers and developers to analyze and share information in order to develop new solutions to the city's problems via a live city test bed.

The goal was to create a multi-tenant, multi-service converged network, in which users experience the network as a single service no matter where they are in the city or which services they are using.

At the heart of the infrastructure is an OpenFlow-based, SDN-controller providing intelligence to the network, enabling a host of different experiments to be conducted simultaneously across the network. The SDN controller will identify flows for given applications so that it can configure specific points in the infrastructure to properly route the data flows based on a pre-defined set of operational requirements, such as latency or bandwidth.

Bristol is Open is also using NFV to turn specific functions which used to require dedicated devices into software. All the basic network functions such as firewalls and user authorization can be assigned to specific projects as required because they are running as virtual machines on standard computing hardware and not function-specific servers.

By implementing both SDN and NFV, the Bristol is Open network can easily make changes to the network if requirements – such as those associated with IoT – change, enabling better manageability, integration, accessibility and agility not found in previous architectures.

Smart Networks = Smart Cities

The vision of most smart city initiatives is to make the city work better for citizens to live, work and play. To realize this vision, cities must have both an agile and scalable infrastructure that can evolve to support a disparate range of applications and services. 

While the introduction of smart services is attractive, city and network planners will need to ensure the technology platform and architecture are capable of supporting both current and future needs.

Virtualization technologies, such as SDN and NFV, offer the flexibility, automation and programmability necessary to create an infrastructure that is fluid and sliceable, with the ability to dynamically address and react to the behavior of the information being captured as well as addressing new requirements and services as they emerge.

That’s a tall order – and it’s likely to take a while to implement. But cities can looks towards Bristol is Open as an example of what can and should be done to truly make a city smart.