Google and Broadcom are offering to study television power in different markets as the FCC investigates the necessity for a guard band in its upcoming broadcast incentive auctions.

Google acknowledged in an ex parte filing that a guard band between LTE and broadcast signals is being considered ahead of the FCC’s 600 MHz incentive auction, scheduled for mid-2015, as a means of battling potential interference.

Slides attached to the filing provided samples of how Google and Broadcom would map out and display the TV power signal findings. The sample maps included New York, Chicago, Los Angeles and San Francisco, but Google insisted that the data displayed was in no way final.

In November, Google representatives met with the FCC to advocate for permitting unlicensed operations in the incentive auction guard band. Google has been promoting the use of unlicensed spectrum. Earlier this year, Google began a public trial with the FCC for a database cataloging all of the available TV white space spectrum available in the U.S.

In addition to pushing for unlicensed use in the guard band and the duplex gap associated with the “down from 51” incentive auction plan, Google suggested opening up unused TV channel, Channel 37, and broadcast channels currently set aside for wireless microphones users.

Audio company Sennheiser has petitioned the FCC to force 600 MHz auction winners to reimburse wireless microphone companies for equipment rendered useless once they have to relocate from the 600 MHz band. CTIA has opposed Sennheiser’s request.

The rulemaking and policy-setting process for the 600 MHz incentive auction is likely taking longer than expected. FCC Chairman Tom Wheeler recently announced that the auctions, originally thought to be occurring in mid-2014, were now being pushed back to mid-2015. The extra time will be used for policy decisions, developing auction procedures and testing the auction software.