Spectrum for cellular/mobile use
- Lower-frequency spectrum with long wavelengths is highly prized for its ability to travel long distances and penetrate buildings.
- Higher-frequency spectrum can carry dense amounts of data but is more limited in terms of propagation, meaning carriers may need to build more cellular towers or rooftop antennas to compensate.
Types of spectrum used for cellular networks:
- Low-band: Airwaves in 850-MHz band were allocated in the 1980s. Spectrum previously used for over-the-air (OTA) television signals in the 700-MHz band was auctioned in 2014 for $5.3-billion.
- Mid-band: PCS spectrum (1,900-MHz band) was allocated in 1995. AWS-1 spectrum was auctioned in 2008 for $4.3-billion; AWS-3 spectrum was sold in 2015 for $2.1-billion.
- High-band: 2,300-MHz spectrum can be used for mobile and was first auctioned in 2004. Some returned 2,500-MHz spectrum is being auctioned now after it was opened up to mobile use.
Future sources of spectrum for cellular use:
- Low-band 600-MHz: Now used for OTA television broadcast signals, but the U.S. plans to relocate broadcasters and sell spectrum to wireless operators. Canada will follow with auction of its own.
- Mid-band AWS-4: Originally designated for use with satellite phones recently re-classified for land-based mobile services as well. No current ecosystem of devices but could be valuable in the future.
- High-band 3,500-MHz: Now earmarked for fixed wireless access (commonly for rural Internet) but Industry Canada wants to reallocate to mobile use in urban areas.
Spectrum for rural/remote home Internet (fixed wireless access)
- Uses higher-frequency bands such as 2,300-MHz, 2,500-MHz and 3,500-MHz.
- Useful for carry large amounts of data but more limited in propagation.
- Operators say they can reach download speeds of 100 Mbps in tests, but typical download speeds with this technology are around 5 Mbps.
Spectrum for OTA television broadcast
- Local television stations send out broadcast signals “over-the-air” using low-band spectrum.
- In 2011, the industry completed the switch from analog to digital transmission, which uses less spectrum, freeing up space in the 700-MHz band and making it available for mobile use.
- The U.S. and Canada are now planning a further migration of over-the-air signals in the 600-MHz frequency band to free up spectrum for mobile use.
Spectrum for WiFi
- WiFi uses spectrum in two set frequencies that are free for anyone to use: 2,400-MHz and 5,000-MHz.
- These frequencies can transmit a lot of data but have limited propagation qualities, meaning doors, walls, distance etc. limit the signal quality.
Illustrations by Murat Yukselir/The Globe and Mail