Representation of Transmitter Characteristics Month Year doc.: IEEE 802.11-yy/xxxxr0 December 2011 Representation of Transmitter Characteristics Date: 2011-12-20 Authors: Steve Shellhammer, Qualcomm Inc. John Doe, Some Company

Month Year doc.: IEEE 802.11-yy/xxxxr0 December 2011 Abstract In some regulatory domains it may be required to transmit to the database some of the transmitter characteristics of the AP and STAs. These transmitter characteristics may include the spectral mask and the maximum antenna gain. This presentation proposes a information element (IE) that can be used to transmit these transmitter characteristics from the STAs to the AP, so that the AP can provide them to the database Submission addresses the following CIDs: 1183 and 1184 Steve Shellhammer, Qualcomm Inc. John Doe, Some Company

December 2011 Motivation Some regulatory domains (e.g. Ofcom) will provide different channel availability and maximum transmit power depending on the STA TX characteristics TX characteristics include spectral mask and maximum antenna gain Both the antenna gain and the spectral mask may be carrier frequency dependent IEEE 802.11af is including a representation of the TX characteristics Our goal is to design an accurate and compact representation Steve Shellhammer, Qualcomm Inc.

Proposal – Information Element December 2011 Proposal – Information Element … Element ID Length Control TX Characteristics 1 TX Characteristics 2 TX Characteristics N IE Octets 1 1 1 Control Field Meaning Current TX Characteristics Format 1-255 Reserved The IE contains multiple fields (“TX Characteristics n”) Each field covers a set of channels, to support carrier frequency dependency in the TX characteristics Steve Shellhammer, Qualcomm Inc.

Proposal –TX Characteristics Field December 2011 Proposal –TX Characteristics Field The TX Characteristics Field consists of a number of fields Len Start Stop AGain Spectral Mask Octets 1 2 2 2 4N Field Meaning Format Len Length of TX Characteristics Field Unsigned 8-bit Integer Start Start WLAN Channel Number Unsigned 16-bit Integer Stop Stop WLAN Channel Number AGain Maximum antenna gain (with 0.01 dB resolution) in dBi Signed 16-bit Integer The maximum antenna gain and spectral mask apply for all WLAN channels between the Start and Stop channels Steve Shellhammer, Qualcomm Inc.

Proposal – Spectral Mask Representation December 2011 Proposal – Spectral Mask Representation The Spectral Mask is represented by a piecewise linear curve with the x-axis on a linear scale and the y-axis on a dB scale The spectral mask field consist of a set of points Each point consists of two fields X dimension – Frequency in kHz (unsigned16-bit integer) Y dimension – Spectral mask in 0.01 dB resolution (signed 16-bit integer) F1 M1 F2 Octets 2 Spectral Mask Points M2 FN MN … Spectral Mask Points Meaning Format Fn Frequency value in kHz 16-bit unsigned integer Mn Mask in 0.01 dB 16-bit signed integer Steve Shellhammer, Qualcomm Inc.

December 2011 Illustration (0,0) (2500,0) (2650,-20) (3000,-35) P0 P1 P2 P3 Spectral Mask Points 2500 2650 -2000 3000 -3500 In this example the spectral mask is normalized, but that is not required Steve Shellhammer, Qualcomm Inc.

December 2011 Example Steve Shellhammer, Qualcomm Inc.

Alternative Spectral Mask Representation December 2011 Alternative Spectral Mask Representation In the original spectral mask representation each point is represented by two numbers: frequency and mask. Both of those numbers are 16-bit signed integers One method of requiring fewer bits is to use only an 8-bit number for the mask Reducing to an 8-bit representation for the mask is accomplished by the following, Scale the spectral mask so the maximum value is 0 dB Reduce the mask resolution to 1 dB (versus the much higher 0.01 dB) Represent the mask using an unsigned 8-bit number, which represents the negative of the mask This new spectral mask representation requires only 3 octets for each point, versus 4 octets in the original spectral mask representation Steve Shellhammer, Qualcomm Inc.

Proposal – Spectral Mask Representation December 2011 Proposal – Spectral Mask Representation The Spectral Mask is represented by a piecewise linear curve The spectral mask field consist of a set of points Each point consists of two fields X dimension – Frequency in kHz (unsigned16-bit integer) Y dimension – Spectral mask in 1 dB resolution (unsigned 8-bit integer) F1 M1 F2 Octets 2 1 Spectral Mask Points M2 FN MN … Spectral Mask Points Meaning Format Fn Frequency value in kHz 16-bit unsigned integer Mn Negative of Mask in dB 8-bit unsigned integer Steve Shellhammer, Qualcomm Inc.

Illustration – Alternative Representation December 2011 Illustration – Alternative Representation (0,0) (2500,0) (2650,-20) (3000,-35) P0 P1 P2 P3 Spectral Mask Points 2500 2650 20 3000 35 Steve Shellhammer, Qualcomm Inc.

December 2011 Conclusions Support for representation of both maximum antenna gain and spectral mask Support for dependency on carrier frequency of both maximum antenna gain and spectral mask Steve Shellhammer, Qualcomm Inc.

December 2011 References Peter Ecclesine, “Spectrum Mask Descriptor Examples,” IEEE 802.11-11/1349r1, September 2011 Chen Sun, Zhou Lan, Yohannes Alemseged and Hiroshi Harada, “Network channel control with spectrum mask,” IEEE 802.11-10/1232r8, September 2011 Chen Sun, Zhou Lan, Yohannes Alemseged, Hiroshi Harada and Jens Tingleff, “Spectrum Mask Descriptor in TLV Format,” IEEE 802.11-10/1292r0, September 2011 Steve Shellhammer, Qualcomm Inc.