SellTower Signals
Interfering with LightSquared
January 21, 2011 Analysis of: NTIA to FCC: LightSquared May Cause Interference | www.wirelessweek.com
This analysis is solely the work of the author. It has not been edited or endorsed by GLG.
Summary
The NTIA told the FCC that federal agencies including Homeland Security are concerned that LightSquared’s satellite-terrestrial LTE network will interfere with government communications services. Many in the industry worry that this will be the end of LightSquared. Yet why would LightSquared shy away from using the spectrum that it has invested so much to own? It is more likely that both the government and the wireless carriers will have to upgrade their GPS equipment.
Analysis
The NTIA has told the FCC that several federal agencies including Homeland Security are concerned that LightSquared’s satellite-terrestrial LTE network will interfere with government communications services. In a Jan. 12 letter to the FCC, NTIA chief Lawrence Strickling said that LightSquared’s hybrid mobile broadband services raise “significant interference concerns.”
The technical issue is that many GPS antennas do not have filters that limit their transmit/receive signals to specific spectrum bands. Therefore, signals in LightSquared’s spectrum have the potential to cause interference when in close proximity to unfiltered GPS antennas. Wireless carriers almost universally ignored the FCC’s advice years ago that they deploy more expensive GPS antennas with proper filters. Enough time has passed that going with unfiltered GPS antennas was probably the right decision. Now it is time to pay the piper. Rather than upgrade antennas, everyone wants LightSquared to just go away.
If precedents hold true, LightSquared will be able to use the spectrum that it owns, and everyone else will have to vacate their electromagnetic premises. Many owners of unlicensed microwave paths were forced to relocate after the AWS spectrum auctions. The wireless carriers also had to install filters when Nextel (NYSE:S) moved into the 800 MHz spectrum band.
Even if the government pushes the interference issue, I do not expect LightSquared to back down. Instead, they are likely to defend their property rights.
