doc.: IEEE /1421r0 Submission November 2012 Rich Kennedy, Research In MotionSlide 1 TGaf Response to CA Comments Date: Authors:

doc.: IEEE /1421r0 Submission Comment #1 The document starts with a statement saying: “At this time, there are no approved standards for operation in the TV white spaces bands.” This is unacceptable since IEEE Std was approved in July 2011 and is specifically aimed for the TV white space bands. There are pre products already out there in the market and some have passed the regulatory approval process. The Co-existence Assurance Document deals with “approved” standards, especially IEEE 802 standards, and not actual systems used in the bands. This statement is unacceptable as written.

doc.: IEEE /1421r0 Submission Reply #1 At the time the CA document was prepared, January of 2011, there were no approved standards for operation in the TV white spaces bands. The first line of the section headed Introduction was changed to: “At this time, there are two approved standards for operation in the TV white spaces bands: IEEE and IEEE ”

doc.: IEEE /1421r0 Submission Comment #2 Last sentence of the second section: “But as Part 15 devices, there are no regulatory requirements for coexistence with other non-licensed devices.” is inappropriate since the object of the Co- existence Assurance Document is not to respond to regulatory requirements but rather to improve voluntary spectrum usage by coordinating the spectrum use of license-exempt equipment.

doc.: IEEE /1421r0 Submission Reply #2 This comment resulted in no changes in the CA document. The comment is based on a different understanding of the rules of FCC Part 15.

doc.: IEEE /1421r0 Submission Comment #3 In section 3, it is interesting to note that was protecting other systems down to -82 dBm (20 MHz) but other types of systems down to -62 dBm, 40 dB higher. Fortunately, af seems to have improved the situation by protecting down to -72 dBm. Note that the receiver sensitivity level is -95 dBm, some 23 dB lower than the protected level. This will reduce the dynamic range of systems by 23 dB which is not negligible and is likely to affect the performance of the receivers

doc.: IEEE /1421r0 Submission Reply #3 This comment resulted in no change to the CA document as we saw no possible way to respond.

doc.: IEEE /1421r0 Submission Also Comment #3 In section 4, it seems that the location, channel and transmit power will be fed back to the database. This information being fed back to the database is not a regulatory requirement and may not be available centrally to help coexistence. In fact, it is unlikely that the instantaneous transmit power resulting from the TPC will be fed back regularly. This is misleading and needs to be corrected.

doc.: IEEE /1421r0 Submission Also Reply #3 This comment resulted in the addition of the following change to the section entitled Location Information: “Ofcom published rules require the WSD masters to inform the database of location and intended channel and power information, and receive acknowledgement from the database before transmitting.”

doc.: IEEE /1421r0 Submission Comment #4 In section 5, it is stated that Mode I devices could be controlled by an “enabling station operated by a licensed operator”. This is not what regulatory rules are specifying since these Mode I devices can be enabled by Mode II or fixed ‘unlicensed’ devices. It is not clear what these licensed enabling stations are. This is new. So far the only licensed users in the TV bands are the broadcasters. Are AF broadcast stations?

doc.: IEEE /1421r0 Submission Reply #4 This comment resulted in no changes in the CA document. Unlicensed devices, like Wi-Fi Hotspots can be operated by licensed operators.

doc.: IEEE /1421r0 Submission Subject Paragraph of Comment #5 Basically, a dependent STA shall not transmit, except to authenticate and associate with an enabling AP, unless it has associated with an enabling AP. Furthermore, a dependent STA shall cease to transmit if it has not recently received a Contact Verification Signal from its enabling STA. A dependent STA shall only operate under the control of the enabling AP to which it is associated. November 2012 Rich Kennedy, Research In MotionSlide 12

doc.: IEEE /1421r0 Submission Comment #5 This is something that needs to take up for all the TVWS standards in 802 – Note in the last paragraph that 80211af also suffers from the catch-22 problem that we have in whereby: “…a dependent STA shall not transmit, except to authenticate and associate with an enabling AP, …” As for , the FCC regulations don’t seem to allow for this even if it may involve very short transmission bursts. They will also need to resolve this catch-22.

doc.: IEEE /1421r0 Submission Reply #5 This comment resulted in the addition of this sentence at the end of the paragraph in question: “IEEE document 11-12/1159r2 describes the operation of a Master/Client system, with particular emphasis on enabling signals.”