NTT Demos '11ac' Next-generation Wireless LAN

Jul 6, 2011
Hiroki Yomogida, Nikkei Electronics
The system for transmission
The system for transmission
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The antennas for transmission
The antennas for transmission
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The three antennas for reception
The three antennas for reception
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NTT's booth
NTT's booth
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The maximum PHY (physical layer) rate is 270Mbps.
The maximum PHY (physical layer) rate is 270Mbps.
[Click to enlarge image]

Nippon Telegraph and Telephone (NTT) Corp prototyped a data transmission system for the "IEEE802.11ac" next-generation wireless LAN standard.

NTT demonstrated the system at Wireless Technology Park (WTP) 2011, which is taking place from July 5 to 6, 2011, in Yokohama City, Japan.

The IEEE802.11ac is a next-generation wireless LAN standard aimed to realize an effective throughput of 1 Gbps per system. NTT plans to commercialize the system within a few years as a high-speed wireless LAN system used at homes and offices.

At the WTP, NTT exhibited a system that can wirelessly transmit data to three users at the same time with an effective throughput of 120Mbps. The high-speed wireless transmission was realized by using a space division multiplex connection method based on multi-user MIMO (multiple input multiple output) technology developed by the company and the 5GHz frequency band.

For the new system, NTT used six antennas for transmission and three antennas for reception. On the transmission side, a multi-user MIMO signal processing circuit was formed by using FPGA (field programmable gate array). And it conducts arithmetic processing necessary for space division while switching coefficients. In the future, it will be possible to use a chip dedicated to wireless LAN for conducting the arithmetic processing that is currently carried out by the FPGA, the company said.

NTT has been promoting a transmission method based on multi-user MIMO technology for the IEEE802.11ac. This time, the prototyped system is compatible with the method. The IEEE802.11ac standard is scheduled to be completed in about 2013.

At the WTP, NTT also showcased a transceiver module for millimeter-wave communication using the 60GHz frequency band, planning to make a wireless LAN environment by integrating the module.