Wi-Fi innovations focus on dense data networks
Wi-Fi has made incredibly strong progress in penetrating almost every area where wireless communications are needed, despite its relatively humble roots as a LAN standard only.
It reaches into carrier-class networks and the internet of things as well as high definition home video, and its broad reach is creating an increasingly vibrant set of innovations and start-ups around it. These will be necessary to supplement the work of the standards bodies if the technology is to continue to adapt and advance, and meet the emerging needs of new wireless applications.
A series of interesting developments have been seen in recent weeks, all of which could influence Wi-Fi's positioning in the years ahead. One comes from a Stanford start-up called Kumu, whose new circuit and algorithms allow incoming and outgoing signals to use the same frequency without interference.
That could lead to significantly better spectrum usage and data rates, since all the spectrum could be used for both uploading and downloading at the same time. Radios generally use separate frequencies to send and receive, or switch between send and receive modes on the same frequency, otherwise the outgoing signal will drown out the inbound one. Co-founder Sachin Katti told MIT Technology Review that the Kumu radio generates an additional signal that cancels out the interference.
This is a different approach to established interference cancellation techniques, and could be applied to cellular networks, not just Wi-Fi – and especially in TDD networks where upload and download frequencies are not separated. Kumu will test its radio with “major wireless carriers” from 2014.
Another start-up with big promises is AirPlug, which says its technology delivers an 80% reduction in mobile data traffic burden without the need for new hardware, by combining Wi-Fi and cellular.
The company has scored its first publicly announced deployment of its AirCloud system, with Korea Telecom.
AirCloud combines Wi-Fi offload with mobile video optimization tools. A cloud-based network monitoring platform works in tandem with an on-device client to identify the best connection, whether cellular or Wi-Fi. Of course, that is nothing new but AirPlug says its uniqueness lies in its patented technology which combines Wi-Fi and cellular where necessary, to support a turbo mode for video and audio streaming, something it calls “blended boosting.”
KT claims the system has reduced the burden on its network from mobile video viewing by up to 80%, with an average of 50%, compared to using cellular alone. The policies for selecting Wi-Fi or cellular – and the turbo mode – are set by the operator, which might offer blended boosting as an upsell, to be chosen by the customer in return for a fee, or might choose to decide itself when to apply turbo mode, in order to enhance customer experience overall.
The IEEE 802.11HEW project
Not all the innovation in Wi-Fi comes from start-ups. The good old IEEE 802.11 groups still enhance the platform too, and one of the latest efforts is .11HEW.This is focused on the topical subject of making WLans interact more happily with cellular networks, to promote offload and, in future, full HetNet.
The .11HEW (High Efficiency WLAN) initiative officially advanced to study group stage in July after receiving approval from the IEEE 802 executive committee and so far three meetings have been held to push the standard forward. It focuses on ways to enhance the 802.11 PHY and MAC in the conventional Wi-Fi bands, 2.4GHz and 5GHz, to enhance spectral efficiency and real world throughput, and particularly to improve the performance of indoor and outdoor Wi-Fi access points when they are deployed in dense zones of cells – Wi-Fi and LTE – and so subject to interference.
Bruce Kraemer, who chairs 802.11 and is also a senior manager at Marvell, says the main commercial driver is carrier offload. He told FierceWireless recently that .11HEW aimed to improve the feature set of 802.11 “to make it a friendly option for LTE going forward” and “improve off-loading from licensed cellular networks to unlicensed Wi-Fi networks”. Orange was originally the operator which spearheaded the effort and other major contributors now are China Mobile and NTT Docomo, as well as the predictable vendors such as Qualcomm and Broadcom, as well as Huawei.