Popular location dependent services have serious performance deficiencies
Today’s mobile GNSS technology has significant reliability and accuracy limitations, because it depends on L1 signaling developed in the 1970s. L1 can’t cope with building and tree blockage. In urban areas, positioning can have 40-100 meters of error, placing users on the wrong side of the street, or even on the wrong block. Large position errors significantly degrade popular location dependent services such as rideshare, pedestrian navigation and 911 emergency calls. L1 signals are susceptible to lots of interference, have no error correction, and have low transmission power, limiting position availability, and making legacy L1 dependent receivers less reliable.
L5—The first major navigation satellite upgrade in decades
The good news is that most navigation satellite constellations now broadcast a modernized signal called L5. L5 has error correction, higher transmission power and is in the protected aviation band, making L5 much more reliable than legacy L1. L5 is a dual sideband signal with much more information, opening the door for receivers that can make high precision measurements, and can compensate for multipath.
Hybrid L1/L5 solutions—double the RF receive chain, and limited by L1 performance
SoC providers have adopted dual frequency (L1/L5) architectures to use L5. But hybrid receivers must first acquire L1 before they can take advantage of L5’s accuracy—they won’t work if L1 isn’t acquired. Receiver reliability is limited by L1’s lower reliability. Furthermore, hybrid L1/L5 receivers double the RF front end, increasing antenna subsystem complexity, and increasing RF front end size, power and cost for the OEM.
“While GPS works well under clear skies, its location estimates can be wildly inaccurate (with a margin of error of 50 meters or more) when we need it the most: in densely populated and highly built-up urban areas…”