Telecommunications today and tomorrow
Before we define the targets for tomorrow’s telecommunications, we should first examine how it works today. Most cities already have many existing communications networks operating side-by-side. A typical city may have multiple cellular/mobile networks plus cable, satellite, RF mesh, microwave, radio, fiber optics, WiFi for homes and offices, ZigBee for smart meters and appliances and more (see list on the next page). Sadly, it can be challenging to bridge between today’s networks, making it difficult to achieve the seamless, end-to-end connectivity required for a true smart city.
If that is today’s reality, then where do we want to go next? The smart city of the future is likely to have an underlying fiber optic network as both a metro loop around the city (like a ring road for traffic) and then local access that links buildings to this loop. Incredibly, tests have been able to send 100 terabits per second through a single optical fiber – enough to download the entire contents of the Library of Congress in seconds! Although fibers do not run at this speed in normal usage, the extraordinary headroom in terms of performance increases is clear. Wireless access to this underlying network may be provided by WiFi, by RF Mesh, by cellular/mobile technologies or some combination.
Some businesses have taken steps to support this ‘high-speed fiber backbone.’ These fiber optic networks provide the bandwidth and speed demanded by the Digital Age. The optical network will terminate in network equipment (eg., an optical network unit) that will then break out and deliver IP and other traffic types to their destinations via a local access network. But a city also needs omnipresent wireless to provide access to sensors, controllers, laptops, tablets, smartphones and other mobile devices.
Most importantly, this future city will have a converged architecture embodied in an all-IP, packet-based core network – a unified infrastructure that integrates various wired and wireless technologies, thereby achieving the seamless connectivity required. When we say “converged” or “unified” we do not mean that a city will end up with a single telecommunications system. Rather, we mean that it will end up with a single architecture – a single set of standards – that allow multiple networks to transmit information smoothly. As we move towards the future, interoperability will be key.
Those three elements – fiber plus wireless plus a converged, delayered architecture are the essentials to achieve the high speed, high reliability and high availability telecommunications required in a modern city.