Iconoclastic “last mile” pioneer Wi-Lan today announced its LIBRA 5800 product series has been approved by the Federal Communications Commission for use in the 5.8 GHz frequency band in the United States.
The LIBRA 5800 uses Wi-LAN’s patented W-OFDM (Wide-Band Orthogonal Frequency Division Multiplexing) technology to achieve high-capacity NLOS (non-line-of-sight) network performance.
“This is our first commercial W-OFDM product available for sale in the United States,” said Dr. Sayed-Amr El-Hamamsy, president and chief operating officer, Wi-LAN Inc. “The US is our largest product market and the 5.8 GHz frequency has proven to be very popular there. We expect the high-speed capacity, enhanced features, and non-line-of sight capabilities of the LIBRA 5800 series will significantly grow our sales in the US.”
“LIBRA 5800’s use of W-OFDM technology makes it well suited to dense urban environments, where its high capacity and robust non-line-of-sight capabilities enable much better subscriber coverage than spread-spectrum systems or conventional single-carrier systems. This significantly improves the business model of urban broadband wireless service providers.”
LIBRA 5800 uses similar 256 carrier OFDM technology that has been approved as the mainstream physical layer in the IEEE 802.16a (WiMax).
Just how Wi-Lan differs from the 802.16a standard is a little unclear.
Channel spacing appears to be different. Wi-Lan uses a 10 Mhz channel on the LIBRA 5800 instead of a typical 5-6 Mhz for 802.16a at MMDS frequencies. The common Wi-Fi standard, IEEE 802.11g/a uses 20 Mhz-wide channels (for 54 Mbps). Three air-interfaces are defined in the 802.16a spec; (1) SC2: single carrier modulation, (2) OFDM with Time Division Multiple Access and (3) OFDM with OFDMA (Multiple Access). In the unlicensed 5.8 GHz band, 4 watts EIRP is allowed in a point to multi-point network but clients (point-to-point) can (with a big enough antenna) push a 1 watt radio to 200 watts EIRP.
Orthogonal Frequency Division Multiplexing
| IEEE Standard | Frequency (GHz) | Speed (MB/s) | Distance | Network Type |
| 802.15.3a (MultibandOFDM) | 2.4 | 480 mbps | 30 feet | Personal Area Network (PAN) |
| 802.11a (OFDM) | 5.15-5.85 | 54 mbps | 150 feet | Local Area Network (LAN) |
| 802.11b (CCK) | 2.4 | 11 mbps | 300 feet | Local Area Network (LAN) |
| 802.11g (OFDM, CCK, PBCC) | 2.4 | 54 mbps | 150 feet | Local Area Network (LAN) |
| 802.16a (WidebandOFDM) | 2.0 to 11.0 | 70 mbps | 31 miles | Metropolitan Area Network (MAN) |
| 802.20 (FlashOFDM) | < 3.5 | 1 mbps | 9 miles | Wide Area Network (WAN) |
Wi-Max (802.16a) gets its range by using more carriers (256) for more immunity to interference, uses narrower channels (typically 6Mhz) and provides Quality of Service allowing each station to have pre-determined data rates. Wi-Fi, by contrast uses simpler architecture and is optimized for close range (100-1000 feet).
LIBRA 5800 delivers up to 32 megabits per second (Mbps) data rate in 10 MHz channels with a range up to 66 kilometres (41 miles) in a point-to-point line-of-sight, or a radius of up to 35 kilometres (22 miles) in a point-to-multipoint line-of-sight configuration.
Wi-Lan provides the wireless backbone for Wireless Calgary and has been working with Fujitsu on a 802.16a chip for more than a year.
