Broadcom Pushes 802.11ac For Faster Wi-Fi

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Gigabit-speed wireless LAN products based on the emerging IEEE 802.11ac standard will start shipping next year and usher Wi-Fi into its next era of high speed and long range, communications chip maker Broadcom said

The new technology will use beam-forming, wide bands and multiple antennas to deliver as much as 1.3G bps (bits per second) of real-world throughput, with a longer range and better wall-penetration capability that will help it serve entire homes, said Rahul Patel, vice president of Broadcom's mobile and wireless group. It represents a big step up from 802.11n, the current standard that typically tops out at about 300M bps, he said.

Consumers will need faster Wi-Fi soon to enjoy activities such as sending multiple streams of video to a TV, Patel said. He presented Broadcom's plan for 802.11ac at a media event in San Francisco that also showcased new technologies for home networking and in-car Ethernet. Broadcom makes processors for a broad range of devices, including cellphones, home media gateways, and enterprise and carrier switches.

The home wireless industry has been weighing several wireless technologies to carry high-definition video, which requires high speed and steady connections. Patel doesn't see the 11ac standard as threatened by two of those systems: 11ac could be a better alternative to Wireless HDMI, which is faster but is too expensive so far for mass deployment, he said. WiGig, which is intended to offer as much as 6G bps but over a shorter range, would probably complement 11ac, Patel said.

The company expects 802.11ac products to start shipping in the second half of 2012, and Patel believes the Wi-Fi Alliance may have a certification program in place by the end of next year, though the actual IEEE standard may not be complete by then. When IEEE 802.11n was still under development by the IEEE, products also started shipping with draft-standard technology certified by the Alliance.

Last month, research company In-Stat predicted that sales of 11ac products would grow rapidly after launch, rising from about 1 million routers, clients and attached modems shipped in 2012 to nearly 350 million in 2015. But even then, 11n will dwarf the new standard, being supported on an estimated 1.5 billion units shipping in 2015.

Like 802.11n, the new standard will take advantage of multiple antennas to create more than one stream of traffic. But an 11ac radio that uses just one stream will be about as fast as an 11n radio with three, Patel said. One way the developers of 11ac will achieve the speed boost of three times or more is by using wider bands, taking up 80MHz or 160MHz of spectrum compared with the 40MHz maximum in 11n. The standard defines how multiple devices using those wide bands can coexist peacefully, Patel said.

Products based on 11ac will leave behind the 2.4GHz frequency band, which is the only space for old 802.11b gear and is an option for 11n products. The new standard will work only in the 5GHz band, which is much less crowded, according to Patel. He estimated that 90 percent to 95 percent of Wi-Fi devices operate in the 2.4GHz spectrum today. That band has just three non-overlapping channels, whereas the spectrum open to Wi-Fi in the 5GHz band has 20 channels.

Beam-forming, which directs a Wi-Fi signal to the best path through space to its destination, is another feature that will boost both the speed and the range of 11ac, Patel said. Several Wi-Fi vendors have been using beam-forming for the past few years with 802.11n, but it will be an integral part of the next standard.

All these performance gains mean radios won't have to spend as much time actually transmitting data, which will help devices make more efficient use of battery power, he added.

Wireless LANs using 11ac play a role in Broadcom's vision of home networks, which sees gateway devices receiving content of all types and distributing it around homes. In homes in different areas, that data will continue to travel over coaxial cable and electrical wiring as well as wireless, with the IEEE P1905 standard allowing those networks to find each other and share the burden of carrying the growing loads of data, said Stephen Palm, senior technical director of Broadcom's Broadband Communications Group.

For connectivity in cars, Broadcom is betting on wires. The company is working with auto manufacturers on implementing Ethernet over thin, lightweight cables, said Kevin Brown, vice president and general manager of Broadcom's Ethernet Transceiver Business Unit. Broadcom hopes to replace specialized auto wiring systems for new features such as multiple cameras around the outside of the vehicle, he said. Using Ethernet would make it easier to introduce new networked entertainment and safety features, he said.


source : pc world