Select language and region
English 日本語 한국어 繁體中文

Navigating the L1, L2 and L5 Band Options for GNSS

L1 L2 and L5

Location adds a lot of value — and not just for real estate. Whether it’s asset tracking, turn-by-turn navigation, or fitness, the ability to pinpoint a person, place, or thing is now a crucial part of most consumer and business applications.

Satellites are a common way to enable location-based services (LBS), which is why global shipments of GNSS devices are expected to continue rising over the next decade, reaching more than 2.2 billion units by 2033. Furthermore, services enabled by GNSS devices are projected to generate over 80% of total GNSS revenues by that time, according to the European Union Agency for the Space Programme (EUSPA) 2024 report. When developing a GNSS-based solution, device OEMs, IoT service providers and systems designers must carefully consider how their spectrum band and constellation choices directly affect accuracy, consistency and more.

The constellation selection has increased significantly over the past decade, with China’s BeiDou and the European Space Agency’s GALILEO joining the U.S. GPS and Russian GLONASS global systems. Two regional systems became fully operational in 2018: Japan’s Quasi-Zenith Satellite System (QZSS) and India’s IRNSS/NavIC.

Every constellation has multiple signals, each operating at its own frequency. This design maximizes accuracy because receivers can use two frequencies to minimize errors created by the ionosphere. Two frequencies also increase the likelihood that signals will be available when the receiver needs them. Some systems use the second or third frequency to provide correction data to enhance accuracy.

L1 L2 and L5 GNSS Frequency Bands

GPS

Nearly every civilian (consumer and enterprise) receiver support GPS’s L1 signal at 1575.74 MHz, which includes the Coarse/Acquisition (C/A) code, alongside the encrypted Precision (P(Y)) code, which only authorized users can access. In the future, the L1 signal will be augmented with L1C to increase availability for civilian users and L1M for military users.

GPS’s L2P(Y) signal at 1227.6 MHz has long been used for precision military applications. Civilian users can also use it in a “codeless” fashion, where the receiver finds the L1 signal first and then uses some of the L2 signal’s information to improve accuracy. As with L1, the GPS modernization program adds two L2 signals: L2C, which is not high precision, but a stronger and slower signal designed to be available in more challenging environments, such as dense urban canyons ). A receiver can access L2C without first receiving L1. The other new signal, L2M, is available only to authorized users.

GPS’s L5 signal at 1176.45 MHz was developed for aviation safety. It’s the most advanced civilian signal available from GPS because it’s faster, like the precision codes at L1 and L2, and for its higher power and lower frequency. L5 is currently widely available from over half of the 31 operational GPS satellites).

GLONASS

GLONASS’s primary signal, sometimes called G1, is near L1, at 1602 MHz. It is unique among all the modern positioning systems because it uses FDMA instead of CDMA, thus undermining its accuracy. Even so, civilian applications have successfully used it for decades.

GLONASS L2 (G2) is located at 1246 MHz and uses FDMA. Plans call for future satellites to transmit at a new frequency, called L3, at 1201 MHz, right next to GALILEO E5b).

Bei Dou

BeiDou B1 is near L1, centered at 1561.098 MHz. A second signal is planned for directly above L1, at 1589.742 MHz. The latest BeiDou satellites also include a signal at 1575.42 MHz that is practically identical to GPS’s L1C.

For its dual-frequency operation, BeiDou’s lower frequency, B2, is at 1207.14 MHz. Much like the modernized GPS L2 signal, a narrower signal is openly available, while a wider, higher-precision signal is available only to authorized users.

Like GALILEO, BeiDou has a third signal, B3, located above B2 at 1268.52 MHz. It’s available in open and authorized-user-only versions.

GALILEO

GALILEO satellites transmit the E1 signal on the same 1575.42 MHz frequency as GPS’s L1. E1 is designed to coexist with this and other nearby signals. It’s also very similar to GPS’s L1C.

Although GALILEO is purely a civilian system, it also has a set of signals called Public Regulated Service (PRS) that is exclusively for authorized users. One is centered at E1 and the other at E6. These signals are wider in bandwidth than Open Service signals.

GALILEO’s E5 signal is split into E5a and E5b, each 20.46 MHz wide. E5a is centered at 1176 MHz, which is co-located with GPS’s L5, while E5b is centered at 1207 MHz. They can be used independently or together. Like GPS’s L5, E5 is designed to provide higher precision and higher availability.

GALILEO’s E6 signal is centered at 1278.75 MHz. Co-located with and similar in use to QZSS’s L6 signal, E6 transmits correction data for high-accuracy services, typically to provide precise point positioning (PPP). E6 also provides a higher data rate, making it ideal for applications that require global, high-accuracy positioning.

IRNSS/NavIC

IRNSS has two signals: one co-located with GPS L5 at 1176.75 MHz and the other at 2492.028 MHz. This latter signal (in S-band) is currently unique among positioning systems. Receivers can use the L5 signal — along with GPS, GALILEO, BDS or GLONASS signals in the L1 band — to provide the benefits of the dual-frequency operation. Both signals can be used independently to provide a single-frequency position.

QZSS

QZSS has four signals. Three are nearly identical to GPS at L1, L2 and L5, while the fourth is a new signal at L6 (co-located with E6) at 1278.75 MHz. Like GALILEO’s E6, the L6 (also known as LEX) signal provides data faster, enabling the distribution of new data types. This is now being used to provide free, open correction data, allowing for free PPP in the region, something that previously was available only from subscription L-band services.

Typical Receiver Combinations

In the past, a dual-band receiver might simply be one that could receive both GPS and GLONASS L1. Today, this level of functionality is expected, so a modern “single-band” receiver typically supports GPS L1, GLONASS L1 and BeiDou B1, which are three different frequencies. Many modern receivers also support GALILEO E1.

True multi-band receivers are becoming more common in response to demand for greater accuracy and more robust locating performance. These integrate at least one other “significantly different” frequency from the L1/B1/E1 band set. In the past, this often meant strictly supporting GPS L1, GPS L2P(Y) (codeless or not) and maybe GLONASS L1. Modern multi-band receivers have higher expectations placed on them and typically fall into a handful of groups:

  • Commercial/Industrial:
    • GPS L1C/A, L1C, L2C
    • GLONASS L1, L2OF
    • BDS B1 (possibly also B2)
    • GALILEO E1, E5b
  • Consumer/Commercial:
    • GPS L1C/A, L1C, L5
    • GLONASS L1
    • BDS B1
    • GALILEO E5a
  • Consumer/Commercial (India subcontinent only):
    • GPS L1C/A, L1C
    • GLONASS L1
    • BDS B1
    • GALILEO E5a
    • NAVIC/IRNSS L1C, L5
  • High-Precision/Reference:
    • GPS L1C/A, L1C, L2P(Y) (codeless), L2C
    • GLONASS L1, L2
    • BDS B1, B2, B3
    • GALILEO E1, E5, E6
    • QZSS L1C, L6
    • NAVIC/IRNSS L1C, L5

All of this is a lot to consider. That’s why device OEMs, IoT service providers and systems designers frequently need another type of navigation: an experienced partner to help them navigate their GNSS integration.

Device original equipment manufacturers (OEMs) frequently require additional in-house RF resources for the seamless integration of the appropriate module and antenna into their designs, ensuring consistent and reliable performance. Opting for an antenna manufacturer capable of aiding in the design and optimization of RF and antenna functionality can bring substantial advantages to device OEMs in terms of accelerating their time to market. Taoglas provides design support, enabling customers to attain enhanced positional accuracy (down to the centimeter level) through the testing of high-precision GNSS antennas in anechoic chambers and open-sky environments. These engineering services serve to simulate the anticipated values in a field test, significantly enhancing product performance and minimizing the risk of design flaws.

By default, we will search the Taoglas Product Catologue which includes in excess of 900 products.

However, if you wish to find non-product content such as a Support Document or Press Release, choose Search Website.

Search Results