FEDERAL COMMUN ICATIONS COMMISSION 
WASHIN GTON 
OFFICE OF 
THE CHAIR M AN 
The Honorable Ron Johnson 
Chairman 
June 29, 2015 
Committee on Homeland Security and Governmental Affairs 
United States Senate 
340 Dirksen Senate Office Building 
Washington, D.C. 20510 
Dear Chairman Johnson: 
Thank you for your letter concerning the Federal Communications Commission's position on the 
use of Wireless Intrusion Detection Systems and Wireless Intrusion Prevention Systems (WIDS/WIPS) to 
protect wireless networks and users from cyberattacks. Your letter raises important legal and policy 
questions that underscore the need to balance the practical needs of network operators to protect their 
systems with consumers' expectation of easy utilization ofWi-Fi access points. The FCC is committed to 
striking the right balance between ready access to unlicensed spectrum and effective cyber defense. 
Accordingly, our enforcement activity in this arena has focused on circumstances where companies are 
not "defending" their networks, but instead are using these capabilities to knowingly deny legitimate 
users access to shared unlicensed spectrum. 
Your letter expresses concern regarding a perceived tension between the FCC Enforcement 
Bureau's January 27,2015 Enforcement Advisory on Wi-Fi blocking,1 and the Department of Homeland 
Security's Wireless Local Area Network (WLAN) Reference Architecture publication regarding the use of 
WIDS/WIPS by Federal agencies.2 Although the Commission's jurisdiction is limited to non-federal uses 
of the radiofrequency spectrum, we understand the two documents to be consistent in their positions that 
network operators should not use "blocking" to interfere with the operation of independent wireless 
networks. 
As a general matter, Enforcement Advisories serve to educate businesses and consumers about 
what the Communications Act of 1934, as amended, and the FCC's rules require, the purpose and 
importance of those laws and rules, and the consequences of failure to comply. Enforcement Advisories 
thus simply illuminate issues for the benefit of the public and entities that may be subject to the 
Commission's jurisdiction. 
1 See https://apps.fcc.gov/edocs public/attachmatch/DA-15-113A !.pdf ("FCC ENFORCMENT ADVISORY­
WARNING: Wi-Fi Blocking is Prohibited"). Your letter also references an Enforcement Advisory issued on March 
6, 2012. See https://apps.fcc.gov/edocs public/attachmatch/DA-12-347 A l.pdf ("FCC CONSUMER ALERT: Us ing 
or Importing Jammers is Illegal"). 
2 Dep't of Homeland Sec., Nat'l Cyber Sec. Div. , Wireless Local Area Network (WLAN) Reference Architecture 
sect. 4.4 (2011) (DRS Reference Architecture). 
Page 2-The Honorable Ron Johnson 
The Enforcement Advisory referenced in your letter provided narrowly tailored guidance 
regarding behavior that is prohibited by Section 333 ofthe Communications Act, which states that "[n]o 
person shall willfully or maliciously interfere with or cause interference to any radio communications of 
any station licensed or authorized by or under this Act or operated by the United States Government." 
The Enforcement Advisory did not change policy regarding the legitimate use of WIDS/WIPS by non­
federal users and does not address any practices of federal government network operators, over which the 
FCC has no statutory jurisdiction. 
The Enforcement Advisory states that no hotel, convention center, or other commercial 
establishment or the network operator providing services at such establishments, may intentionally block 
or disrupt personal Wi-Fi hot spots on such premises, including as part of an effort to force consumers to 
purchase access to the property owner's Wi-Fi network. The Enforcement Bureau issued this advisory 
following its 2014 Consent Decree with Marriott International, Inc., in which the company deployed a 
Wi-Fi deauthentication protocol to deliberately and indiscriminately block consumers who sought to 
connect to the Internet using their own personal Wi-Fi hot spots. In that case, Marriott admitted that the 
customers it blocked did not pose a security threat to the Marriott network and agreed to settle the 
investigation. Because the FCC had received several complaints that other commercial Wi-Fi network 
operators might be disrupting the legitimate operation of personal Wi-Fi hot spots, the Enforcement 
Bureau issued the advisory to provide more information to businesses and consumers. 
The Enforcement Advisory is consistent with the DHS document. For example, the DHS 
document states that a federal agency should recognize that there may be independent Wi-Fi networks in 
the vicinity of the agency's operations and the agency should not configure its WIDS/WIPS to 
automatically block them. Indeed, the DHS document calls for federal agencies to address and plan for 
legitimate external Wi-Fi use, and notes that WIDS/WIPS have features that enable a security specialist to 
monitor legitimate threats while identifying non-threats caused by these cases of overlapping local area 
networks. 
The FCC recognizes and values the significant experience that DHS and other federal partners 
bring to this crucial cybersecurity discussion, and the FCC and DHS regularly share expertise in support 
of our independent yet complementary missions. The FCC enjoys a longstanding and mutually-beneficial 
working relationship with DHS and other interagency partners. 
Thank you for your interest in this matter. The security of our nation's communications network 
is vital to both private and public sectors. We recognize that there is additional work to do to defme 
defensible best practices for shared unlicensed bands, and we look forward to working with our federal 
partners to develop these best practices. 
;;;-lf~ L-
Tom Wheeler 
FEDERAL COMMUNICATIONS COMMISSION 
WASHINGTON 
O FFICE O F 
T HE C H A IRMAN 
The Honorable Michael McCaul 
Chairman 
Committee on Homeland Security 
U.S. House ofRepresentatives 
H2-176 Ford House Office Building 
Washington, D.C. 20515 
Dear Chairman McCaul: 
June 29, 2015 
Thank you for your Jetter concerning the Federal Communications Commission's position on the 
use of Wireless Intrusion Detection Systems and Wireless Intrusion Prevention Systems (WIDS/WIPS) to 
protect wireless networks and users from cyberattacks. Your letter raises important legal and policy 
questions that underscore the need to balance the practical needs of network operators to protect their 
systems with consumers' expectation of easy utilization ofWi-Fi access points. The FCC is committed to 
striking the right balance between ready access to unlicensed spectrum and effective cyber defense. 
Accordingly, our enforcement activity in this arena has focused on circumstances where companies are 
not "defending" their networks, but instead are using these capabilities to knowingly deny legitimate 
users access to shared unlicensed spectrum. 
Your letter expresses concern regarding a perceived tension between the FCC Enforcement 
Bureau's January 27, 2015 Enforcement Advisory on Wi-Fi blocking, 1 and the Department of Homeland 
Security's Wireless Local Area Network (WLAN) Reference Architecture publication regarding the use of 
WIDS/WIPS by Federal agencies.2 Although the Commission's jurisdiction is limited to non-federal uses 
of the radio frequency spectrum, we understand the two documents to be consistent in their positions that 
network operators should not use "blocking" to interfere with the operation of independent wireless 
networks. 
As a general matter, Enforcement Advisories serve to educate businesses and consumers about 
what the Communications Act of 1934, as amended, and the FCC' s rules require, the purpose and 
importance of those laws and rules, and the consequences of failure to comply. Enforcement Advisories 
thus simply illuminate issues for the benefit of the public and entities that may be subject to the 
Commission's jurisdiction. 
1 See https: //apps.fcc.gov/edocs public/attachmatch/DA- I 5-113A !.pdf ("FCC ENFORCMENT ADVISORY­
WARNING: Wi-Fi Blocking is Prohibited"). Your letter also references an Enforcement Advisory issued on March 
6, 2012. See https://apps.fcc.gov/edocs public/attachmatch/DA-12-347 A ! .pdf ("FCC CONSUMER ALERT: Using 
or Importing Jammers is Illegal" ). 
2 Dep't of Homeland Sec., Nat' I Cyber Sec. Div., Wireless Local Area Network (WLAN) Reference Architecture 
sect. 4.4 (2011) (DRS Reference Architecture). 
Page 2-The Honorable Michael McCaul 
The Enforcement Advisory referenced in your letter provided narrowly tailored guidance 
regarding behavior that is prohibited by Section 333 of the Communications Act, which states that "[n}c 
person shall willfully or maliciously interfere with or cause interference to any radio communications of 
any station licensed or authorized by or under this Act or operated by the United States Government." 
The Enforcement Advisory did not change policy regarding the legitimate use of WIDSIWIPS by non­
federal users and does not address any practices of federal government network operators, over which the 
FCC has no statutory jurisdiction. 
The Enforcement Advisory states that no hotel, convention center, or other commercial 
establishment or the network operator providing services at such establishments, may intentionally block 
or disrupt personal Wi-Fi hot spots on such premises, including as part of an effort to force consumers to 
purchase access to the property owner's Wi-Fi network. The Enforcement Bureau issued this advisory 
following its 2014 Consent Decree with Marriott International, Inc., in which the company deployed a 
Wi-Fi deauthentication protocol to deliberately and indiscriminately block consumers who sought to 
connect to the Internet using their own personal Wi-Fi hot spots. In that case, Marriott admitted that the 
customers it blocked did not pose a security threat to the Marriott network and agreed to settle the 
investigation. Because the FCC had received several complaints that other commercial Wi-Fi network 
operators might be disrupting the legitimate operation of personal Wi-Fi hot spots, the Enforcement 
Bureau issued the advisory to provide more information to businesses and consumers. 
The Enforcement Advisory is consistent with the DHS document. For example, the DHS 
document states that a federal agency should recognize that there may be independent Wi-Fi networks in 
the vicinity of the agency's operations and the agency should not configure its WIDS/WIPS to 
automatically block them. Indeed, the DHS document calls for federal agencies to address and plan for 
legitimate external Wi-Fi use, and notes that WIDSIWIPS have features that enable a security specialist to 
monitor legitimate threats while identifYing non-threats caused by these cases of overlapping local area 
networks. 
The FCC recognizes and values the significant experience that DHS and other federal partners 
bring to this crucial cybersecurity discussion, and the FCC and DHS regularly share expertise in support 
of our independent yet complementary missions. The FCC enjoys a longstanding and mutually-beneficial 
working relationship with DHS and other interagency partners. 
Thank you for your interest in this matter. The security of our nation's communications network 
is vital to both private and public sectors. We recognize that there is additional work to do to define 
defensible best practices for shared unlicensed bands, and we look forward to working with our federal 
partners to develop these best practices. 
Sincerely~ 41-
-~eeler