White space spectrum has been hyped as a solution to a number of wireless applications suffering from the lack of spectrum—or its high price. Yet no real solution from manufacturers has come forth until now. Neul’s NeulNET products implement a full white space radio system. Initially targeting the machine-to-machine (M2M) communications space, the system has potential in the smart meter communication space and local broadband delivery.
White space comprises the spectrum chunks for unused TV channels in the UHF range, usually 450 to 700 MHz. These 6-MHz channels in the U.S. (8 MHz in the U.K.) can be used for data transmission as long as the signals don’t interfere with adjacent channel TV signals. This chopped up spectrum came about as the broadcast TV stations switched from analog to digital signals a few years ago.
In the U.S., the Federal Communications Commission (FCC) does not require licensing to use these channels, but the equipment must meet stringent specifications to avoid any TV or wireless microphone interference. Neul is the first company to offer white space hardware that can meet the FCC’s challenging adjacent channel power specification.
The NeulNET system consists of a NeulNET 1 basestation and a NeulNET user terminal (see the figure). The fixed customer premise equipment (CPE) terminal is available now, with a portable battery-powered terminal to be available shortly. The basestation uses two antennas for diversity reception, boosting link reliability. Up to 16-Mbit/s data throughput is available per channel. The total range is up to 10 km depending on location, antenna placement, and other factors.
The NeulNET basestation is connected by Ethernet backhaul to the Internet for access to the Neul Spectrum Management database, which holds the information for each locality including available frequency channels and potential interference sources. The basestation adjusts its frequency accordingly.
The Neul radios do not use orthogonal frequency-division multiplexing (OFDM) like other broadband systems. Instead they use a single carrier signal with a downlink of 16-phase quadrature amplitude modulation (16QAM) and an uplink of binary phase-shift keying (BPSK) or quadrature phase-shift keying (QPSK) depending on link conditions.
Neul is working to make its Weightless wireless system an open royalty-free standard. Forthcoming next year is the NeulNET 2 cost-reduced terminal with an integrated Wi-Fi access point and full battery-powered portable operation. Also coming in 2012 is a chipset that is expected to sell below $5 with a 10-year battery life potential.
Neul chose M2M as its initial market push simply because of its huge potential. With the projected 50 billion connected devices by 2020 creating the Internet of Things, all sorts of embedded radios are possible in every consumer or commercial product. While most M2M installations use 2G or 3G cellular systems today, they’re too expensive and power-hungry for some products. Future cellular cost and capacity could also be issues.
White space products can fulfill some of these other applications at lower cost. Smart meter communications back to the utility is another potential application. The Neul solution is also ideal for implementing rural broadband connections.
The Neul equipment is available now. In single-unit quantities, the basestation costs $16,000, and the terminal is $8000. Both as a package cost $20,000. Volume discounts are available as well.