Q: In what frequency band does the LocataNet operate?
A: The Locata frequency choice for the current devices is the 2.4 GHz Industrial, Scientific, and Medical (ISM) band. This ISM band is available worldwide without licenses. It is the same band used by Wi-Fi (802.11b & g) and Bluetooth. The Locata technology can be configured to operate at other frequencies, but initially the ISM band provides a straightforward, license free, continuous frequency spectrum. Using the ISM band allows the Locata system to co-exist with GPS signals (not jam GPS) and permits a Locata-enabled receiver to simultaneously use GPS and Locata signals.
Q: Does Locata interfere with Wi-Fi, or vice versa?
A: No. We have gone to great lengths to ensure Locata can inter-operate with Wi-Fi without evident deleterious effects on either network system. Locata is currently deployed in open-cut mine environments where the entire mine is covered in Wi-Fi signals, both for operational network and back-haul use. Our integration partners wanted to see and trial robust operation in the Wi-Fi band before committing to product development, as inter-operation was a necessary and essential requirement.
Q: What area can be covered by a LocataNet?
A: The answer is – it depends on what you need. We have run a LocataNet in an area as small as a basketball court. Our R&D Test Facility outside Canberra (Australia) covers 300 acres with up to 2.4km between LocataLite transmitters (marked "x" in the pic below). The USAF has run LocataNets which cover very large (> 50km) areas. Notionally, a LocataNet can be propagated over even longer distances, and two separate LocataNets may be joined together to form a larger, “super” LocataNet. We certainly expect that LocataNets will cover entire cities in the future.
Locata's wide-area network facility covering 300 acres,
with up to 2.4km between LocataLite ("x") transmitters.
Early indoor demonstration of Locata technology inside a basketball court.
Q: What is the transmission power of a LocataLite?
A: The maximum signal power for devices in the ISM band is restricted by international regulations to +8 dBm within a 3 kHz bandwidth, to a maximum of 1 Watt. Locata complies with this FCC regulation.
Q: What range does a LocataLite transmission cover at this power?
A: Without obstructions, the range of the LocataLite signal is tens of kilometers, and is limited mainly by terrain, much the same as mobile phone systems. However, at this time, Locata does not recommend separation of more than 5km between LocataLites.
Q: What if I need more signals, or I need to “expand” the range of a LocataNet?
A: If more signal power is needed, additional LocataLites can be added. This is the same model used by mobile phone operators who add towers to increase coverage in a specific area. For example, to increase the signals in a local shopping mall, the mobile phone operator adds mobile phone towers near the mall. Additional LocataLites can be added in much the same way, inside or outside a LocataNet coverage area, to provide additional location signals. Locata networks could have as few as four or five LocataLites, or up to thousands of transmitters.
Q: Does Locata actually transmit GPS signals?
A: Not exactly. LocataLites generate signals that have a similar structure (i.e. direct sequence spread spectrum) as GPS signals, but at a different frequency. LocataLites actually transmit a variety of signals. Some signals are almost identical to the GPS satellite signals and others are Locata-designed to provide better measurements in environments where GPS was not originally designed to work. For example, when standard GPS signals are broadcast inside buildings, the signals bounce around badly, resulting in many signals being received from a single transmitter - the ones that bounced around and those that didn’t. Determining the distance to the transmitter from these bouncing signals (called multipath) is extremely difficult. However, the signals generated by Locata allow for easier determination of the distance to the transmitter. This unique combination of signals provides an extremely accurate and tailored ranging system.
Q: How accurate a position can a LocataNet produce?
A: Without sounding coy, the real answer is – it depends on many factors! Technically, Locata positioning is capable of - and regularly delivers - centimeter-level accuracy. Locata navigation positions are generated by what the industry calls a "carrier-phase single-point solution". Locata is the only technology in the world that can achieve this accuracy without requiring any external assistance or information. Survey-grade GPS can also deliver centmetre-level "carrier-phase" positioning, but not as a "single-point solution". This means that to obtain high accuracy from GPS, surveyors have to have access to a lot of other complex and additional technology (such as reference receivers, differential correction networks and communication data links) to help GPS remove the errors in their system. This is definitely not the "standard" GPS technology which consumers are familiar with. Survey-grade GPS receivers cost upwards of US$25,000, so do NOT expect your Garmin or Tom-Tom PND to ever come close to this level of accuracy. Or... at least not until the Garmin or Tom-Tom PND is "Locata-enabled" as well! Please read the independent papers to get a feel of what accuracy level our partners are achieving, and the points that should be addressed when deploying a LocataNet. Nevertheless, it should be clearly understood that the inherent positioning capability of a LocataNet is extremely good (see page 7 of Leica’s independent testing as presented to the Institute of Civil Engineers (ICE) Conference - Beijing Sept 2007 to appreciate just how good!), and that careful LocataNet deployment can achieve superb results.
Q: How has Locata achieved this unique ability to replicate a GPS constellation on the ground?
A: Apart from the distinctive LocataNet structure, the core invention which underlies Locata technology is a completely new synchronization method we call Time-Loc. Many people do not realize that the synchronization of transmitters is essential in an autonomous radio-location system. This is one of the critical requirements for GPS, and hence each GPS satellite contains 3 or 4 atomic clocks (if you are interested in finding out more about how GPS works, go here: http://en.wikipedia.org/wiki/Gps#Technical_description) Time-Loc allows our LocataLite devices to achieve absolutely incredible timing accuracy but - for the first time ever – we can achieve this without having to use atomic clocks. There is no other technology in the world that can do this.
Q: How does Time-Loc work?
A: Frankly, it’s not easy to explain in just a few sentences, and some basic expertise is required for the technology to be fully understood. A good place to start is by reading paragraphs 2.0 – 2.4 of the University of New South Wales Conference Paper #5, or read the Locata Technology Primer from 2005, and then go on to study the other papers on our web site.
Q: Who is using Locata technology right now?
A: Locata is today focusing on big industrial markets (such as open-cut mining, structural deformation, construction, etc) where our current receiver form-factor and pricing match market expectations. However, our current R&D is focused on next-generation Locata systems that will soon attend to markets such as warehouse automation, supply-chain management, emergency services, surveying/engineering and the military. We have a technology development roadmap in place that will produce miniaturized Locata devices to service the consumer and telecom markets in the future.
Q: Where can I buy a LocataNet, and how much does it cost?
A: We get asked this all the time, and we know there is a huge demand out there from many markets for the functionality Locata can provide. Unfortunately, Locata does not currently have the resources or company structure to sell LocataNet systems to end-user customers. Locata’s go-to-market model is based on building and fostering relationships with Systems Integrators and Value-Added Resellers, like those shown here. We are also working quietly with a number of other global partners under NDA. If you are an integrator interested in discussing a relationship with Locata for specific markets, please e-mail us here.
More FAQ's to come.
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