Digital terrestrial towers may become a thing of the past.
Visitors to IBC 2017 this September in Amsterdam might have concluded that a prediction made almost 20 years ago that over the air services such as TV transmission would migrate to the ground while those already on the ground such as voice telephony would take to the air has now completely come true. They would have witnessed the bullishness of Wi-Fi proponents combined with the low visibility of the principle wired alternatives, Multimedia over Coax Alliance (MoCA) and Home Plug powerline (PLC) for transmission over power cables.
That prediction was made by Nicholas Negroponte, Internet pioneer and founder of the Massachusetts Institute of Technology's Media Lab, in the late 1990s at a time when this trend was already underway for external services. It is only recently that the prediction has started to become true inside the home with the advance of Wi-Fi and especially the development of wireless mesh technologies that overcome the challenge of ensuring the consistently high bit rates necessary for HD and even Ultra HD video at all parts of a building.
This point has not quite been reached yet but it is clear that is where broadcasting is heading, as several leading pay TV operators have made clear. Sky Europe for example is now delivering its video services over Wi-Fi to connected devices and the main TV from its Sky Q box, exploiting mesh technology developed by Turkey-based AirTies. At the moment Sky is using PLC as a backbone to overcome attenuation of signals through thick walls and floors, but the intention is to drop that requirement as soon as possible.
At IBC 2017, chip maker Quantenna was busy talking up the trend towards Wi-Fi. “In North America and Western Europe in particular service providers are rapidly moving towards Wi-Fi,” said Quantenna’s Senior Director of Marketing James Chen. “We are seeing more and more RFPs (Request For Proposals) specifying Wi-Fi.” Of course as the world’s only major chip maker specializing exclusively in Wi-Fi we would expect Quantenna to be saying that but the shift to Wi-Fi is undeniable and it is just a matter of how quickly it will take place and whether new build dwellings will cease to be wired with say coaxial cable as they often are at present, especially in the US.
A key factor here will be the rate at which mesh technologies mature and become ubiquitous. It has roots in fixed line networks, especially those based on IP routers, which are typically connected together in meshes comprising multiple interconnected nodes to increase resilience, capacity and load balancing, avoiding any single points of failure. In principle, each router can be connected to all the others, although in practice only to those in its neighbourhood but still if any one fails there should be a path available via others.
The prediction that what used to go over wires would become wireless and what used to be wireless would go over wires is widely attributed to Nicholas Negroponte, founder of the Massachusetts Institute of Technology's Media Lab.
Wireless mesh then arose effectively by just removing the wires between the routers, while the principle of providing multiple paths between any two nodes or client devices and avoiding any single point of failure remained. The idea of mesh for wireless dates back at least to 2003 when the first IEEE study group started working on the 802.11s standard. This specifies how Wi-Fi nodes should communicate in a mesh, but it has been a long time in the making. Meanwhile various proprietary Wi-Fi mesh technologies have been developed from the likes of Cisco, D-Link and Netgear as well as AirTies. Such mesh products enable multiple Wi-Fi Access Points (APs) to be deployed such that strong signals reach all parts of a building. Currently with the latest versions of the transmission standards such as 802.11ac it is usually possible to deliver premium video over Wi-Fi within rooms and the idea of mesh is in effect to enable the wireless network to become its own backbone without need for wires. Then whole home video coverage becomes possible.
One advantage of mesh is that it is modular, enabling homes to start small and deploy additional nodes to boost coverage and capacity as they need it. Unfortunately, despite the existence of the 802.11s standard, none of these mesh technologies interoperate, so that once a user has deployed a mesh node they have to stick with the same technology and vendor when they add more, or else ditch what they have got and start again.
According to Chen the Wi-Fi Alliance, which has emerged as the body promoting and stimulating standards for interoperability between Wi-Fi devices, is looking at establishing a common protocol allowing interworking between APs from different vendors, even catering for multiple algorithms for mesh operation within the same network. The algorithms determine factors such as which AP a given device will connect to according to where it is in the building, taking account of the relative signal strengths at that point.
But the algorithms themselves would still remain proprietary, which is why Quantenna itself has incorporated middleware from one or two these specialist vendors, including AirTies, on its chip. But as Chen pointed out this situation may not last, because mesh is coming to be seen as so integral to the operation of Wi-Fi as it becomes ever more mission critical that the Wi-Fi Alliance may act to standardize that to allow full interoperability. This could have a serious impact on those mesh vendors, but for now they are making hay while the sun shines.
One aspect of mesh standardization has already to come to pass with introduction of the Wi-Fi Alliance’s Wi-Fi Certified Home Design program in July 2017. To qualify, new homes have to follow Wi-Fi deployment guidelines to determine the optimal locations for APs, which would ensure the best possible mesh operation, almost irrespective of the actual mesh technology deployed. The goal is just the same as with mesh, to eliminate dead spots and provide coverage everywhere inside the home and indeed around it in the garage and garden for example. In the US homebuilder Lennar became the first to offer Wi-Fi Certified Homes for sale, opening a new chapter for the technology. This is significant for broadband and pay TV operators because for the first time it establishes a fixed fabric for Wi-Fi within the home which potentially will enable them to regain the sort of control over end to end delivery right to the connected device that they have traditionally enjoyed as far as the home gateway or Set Top Box.
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