Interview: Rajeev Jain, Senior Director, Technology, Qualcomm Atheros

March 14, 2012
Interview by Nancy Friedrich
NF: The wirelessly connected home has been a dream of the consumer industry for some time. Now, it is finally coming to fruition, thanks to a hybrid-networking approach supported by the IEEE 1905.1 standard. Can you provide details on this draft standard? RJ: To meet the range and bandwidth requirements of the connected home, the IEEE 1905.1 draft standard allows the consumer to optimally combine Wi-Fi with any of the three popular wireline home networking technologies to form a single "hybrid" network: HomePlug, Multimedia over Coax (MoCA), and Ethernet. IEEE 1905.1 specifies a common protocol that allows devices connected with Wi-Fi and any of these wireline technologies to seamlessly configure themselves into a unified network. Specifically, the IEEE 1905.1 protocol provides a common authentication and security mechanism across these connectivity technologies, as well as common mechanisms for discovering devices and measuring the quality of the communication link between devices. These features can be used by service providers and retail manufacturers to ship networking gear that installs itself, configures itself, and manages all the available bandwidth efficiently to connect any devicebe it a thermostat or high-definition television (HD TV), anywhere in the homeand optimally deliver any type of service to it with no user intervention.

Most importantly, IEEE 1905.1 does not require any changes in the underlying technologies; rather, it provides a common interface to the already standardized MAC layer for Wi-Fi (IEEE 802.11), HomePlug (IEEE 1901), MoCA, and Ethernet (IEEE 802.3). Thus it can also be used to create a hybrid network with devices already deployed in the home with any of these connectivity standards and make the connected home a reality.

NF: The 1905.1 standard will optimize combinations of both wireless and wireline technologies, such as Wi-Fi, HomePlug, Powerline, Ethernet, and Multimedia over Coax (MoCA). What benefits will be provided by such a merged approach?
RJ: The benefits of combining Wi-Fi, HomePlug, Powerline, Ethernet, and MoCA lie mainly in the ability of 1905.1 to make devices with all four technologies operate as if they were on a single network with one shared medium. Therefore, essentially the aggregate bandwidth of the hybrid network becomes the combined bandwidth of all the underlying networks. For example, for video streaming to multiple TVs in the home, if Wi-Fi supports HD quality links with a shared bandwidth of 60 Mb/sand likewise, if HomePlug supports 40 Mb/sa 1905.1 hybrid Wi-Fi/ HomePlug network provides 60 + 40 = 100 Mb/s. A hybrid router based on 1905.1 can optimally decide how to use this aggregate bandwidth across multiple devices so each gets the bandwidth it needs.

Let's assume a consumer needs 20 Mb/s for her Wi-Fi enabled mobile devices (e.g., smartphones, tablets, laptops) and 20 Mb/s per TV for four TVs in the home, adding as much as 100 Mb/s. If the TVs have both Wi-Fi and HomePlug and are 1905.1 enabled, the hybrid router can measure the link quality and bandwidth utilization and decide which medium to use for each TV. In this example, it would select HomePlug for two TVs (using the HomePlug 40 Mb/s shared bandwidth) and Wi-Fi for the other two (using 40 of the available 60 Mb/s Wi-Fi bandwidth). The beauty of the 1905.1 common protocol is that the hybrid router can make this decision in a completely transparent and seamless manner with no user intervention required. The consumer just gets what she wants without worrying about how the TVs are connected or which medium was being used. All she has to do is plug the devices in and power them up, and 1905.1 does the rest. Even more important is that 1905.1 allows this configuration to be done dynamically, while the network is in operation, in case the link quality changes.

NF: What challenges will have to be overcome?
RJ: None. The elegance of the way 1905.1 has been defined is that it is fully backward compatible with the existing standards. Therefore, if a router already has Wi-Fi and HomePlug or MoCA connectivity, it can be converted to a 1905.1 hybrid router in the field by a software upgrade.

NF: Can you explain how wired solutions like MoCA can be used to extend Wi-Fi's range within a home?
RJ: 1905.1-based range extenders that combine HomePlug or MoCA with Wi-Fi also solve the Wi-Fi range problem. Such a range-extender can be plugged in to a wall outlet (powerline or coaxial) in a part of the home where the Wi-Fi signal is weak, and it then becomes an auxiliary access point (AP) for that part of the home. In this case, the auxiliary AP in the range-extender communicates with the main AP in the hybrid router over the wireline link powerline or coaxto exchange security credentials, and automatically configures itself using the 1905.1 discovery, security, and authentication features. The consumer can enjoy the benefit of Wi-Fi connectivity in that part of the house by simply plugging in the 1905.1 range-extender in the wall. If the consumer's Wi-Fi enabled smartphone was already associated with the main AP in the hybrid router in the home, it automatically connects to the range extender auxiliary AP when the user roams to that part of the house.

NF: What role will small cells, such as femtocells, play in this connected home?
RJ: Femtocells will play a role in providing additional coverage and capacity for high-value customers based on cellular technology. The femtocell will provide data and voice services over licensed, managed spectrum and will complement the currently deployed unlicensed connected home technologies. In emerging markets where wireline broadband access is scarce, femtocells will go a long way in providing a link to the Internet via the broadband wireless backhaul.

NF: What role will be played by current providers, such as cable companies, satellite-TV providers, and cellular companies?
RJ: Many providers already use multiple technologies to deliver services in the home (Wi-Fi, HomePlug, and MoCA). With 1905.1 they will be able to tie these into a single seamless network and offer the consumer the advantages of greater wireless range, larger network bandwidth, and guaranteed service quality. For example, content streaming from the Internet gateway in the home over HomePlug or MoCA to a 1905.1 set-top box (STB) could be relayed from the STB to a tablet for viewing over Wi-Fi. Thus, a consumer watching a game on a TV via the STB, who needs to walk to another room, can seamlessly pick up the game on her Wi-Fi enabled tablet as she walks out. So, providers will play a key role in driving 1905.1 into the marketplace as they offer a better user experience by taking advantage of the 1905.1 protocol.

NF: Do you expect such capabilities to include "smart-home" applications like monitoring the energy usage of appliances?
RJ: Absolutely. In fact, the 1905.1 hybrid networking capabilities are essential to driving smart-home applications, since these applications will interact with a diverse set of devices ranging from thermostats to HD TVs, employing a variety of communication technologies with vastly different bandwidth, latency, and robustness requirements. Appliances plugged in the wall can naturally use HomePlug to communicate with the Internet via the 1905.1 hybrid network and other appliances can use Wi-Fi. Thus, energy monitoring apps running on a central hub such as the hybrid router can track energy consumption of all appliances and provide direct feedback to the consumer over Wi-Fi in the home or via the cellular network outdoors to her smartphone. Between the 1905.1 hybrid home network and the smartphone, the consumer will always be "in touch" with everything in the house, from anywhere in the house. This makes the possibility of smart-home apps limitless.

NF: What markets and applications will be most fruitful for the connected home? What new ones will emerge?
RJ: The connected home concept breaks down the barriers that have hampered many of the smart-home applications from reaching their full potential. With the connected home, each and every outlet (power or coax) in the house becomes a data access port. This in conjunction with Wi-Fi will provide connectivity to devices in each and every corner of the house. As a result, all of the current home networking applications will be positively impacted. To mention a few: data delivery services, video distribution services, content delivery services, energy management applications, home monitoring and security services, and data management and storage.

About the Author

Nancy Friedrich | Editor-in-Chief

Nancy Friedrich began her career in technical publishing in 1998. After a stint with sister publication Electronic Design as Chief Copy Editor, Nancy worked as Managing Editor of Embedded Systems Development. She then became a Technology Editor at Wireless Systems Design, an offshoot of Microwaves & RF. Nancy has called the microwave space “home” since 2005.

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