1. Spectrum Mask in IEEE802.11p Date: 2008-03-18 Authors: March 2008
doc.: IEEE /0362r0
March 2008
Spectrum Mask in IEEE802.11p
Date:
Authors:
Hanbyeog Cho (ETRI)
Hanbyeog Cho (ETRI)

2. March 2008
doc.: IEEE /0362r0
March 2008
Abstract
We present the spectrum mask based on the FCC rule. WAVE system specification has mismatched spectrum masks. It means that PER(packet error rates) will be increased due to channel interference between adjacent channels.
This presentation is a following work to the presentation by Vinuth Rai &John Kenny last San Fransisco meeting (17 July, 2008)
The main focus is on the spectrum mask related FCC rule and the spectrum mask should fulfill [55+10log(P)], -25dBm criteria
Then proposed spectrum mask will decrease the interference between adjacent channels
Hanbyeog Cho (ETRI)
Hanbyeog Cho (ETRI)

3. Contents Introduction Cross-Channel Interference Wave Regulation
March 2008
Contents
Introduction
Cross-Channel Interference
Wave Regulation
Spectrum Mask
Hanbyeog Cho (ETRI)

4. March 2008
Introduction
This presentation is relating to the presentation by Vinuth Rai &John Kenny last San Fransisco meeting(17 July, 2008)
p-cross-channel-interference-test-results-a-report-from-the-vsc-a-project.ppt
Main focus : Interference adjacent channel
Spectrum Mask to fulfill [55+10log(P)], -25dBm criteria
Spectrum Mask to fulfill [55+10log(P)] criteria 기준을만족하는
Hanbyeog Cho (ETRI)

5. Cross-Channel Interference
March 2008
Cross-Channel Interference
Effect of cross-channel interference
- Transmit power & channel allocation  cross-channel interference
- Increasing PER
- Solution Need sharp spectrum mask
Ce = Co – Ci
- Ce : Total available channel
- Co : Original channel
- Ci : Channel interference
Channel 2 Ce Ci
Channel 1
Channel 3
Interference
Spectrum Mask to fulfill [55+10log(P)] criteria 기준을만족하는
Hanbyeog Cho (ETRI)

6. Cross-Channel Interference : Example – Using WAVE
March 2008
Cross-Channel Interference : Example – Using WAVE
Toyota ITC test Result :
Adjacent interference
- Tx Channel : 172
- Interferer Channel: 174
Toyota ITC test Result :
Non-adjacent interfer
- Tx Channel : 172
- Control Channel: 178
RX-Interferer Distance (meters) 60 0% 40
10% 30 1%
80% 25
0.5%
99% 20
40%
90%
100% 15
92%
95%
12.5
0.10%
1.50%
70%
98% 10
0.90%
35%
7.5
15% 5
55%
2.5
Legend:
PER > 10% 50
100
150
200
RX-TX Distance (meters)
Spectrum Mask to fulfill [55+10log(P)] criteria 기준을만족하는
Cross-channel interference test results
- Adjacent channel interference
. Packet Error: [Tx-Rx distance] / [Int-Rx distance] > 10 if [PTx =PRx]
- Non-adjacent channel interference
. Less importance
Hanbyeog Cho (ETRI)

7. Maximum device output power Reduction in Power Spectral Density, dBr
March 2008
Wave Regulation
Device classes and Tx power levels
Device class
Maximum device output power
Class A
0 (dBm)
1mW
Class B
10 (dBm)
10mW
Class C
20 (dBm)
100mW
Class D
28.8 (dBm)
750mW
Wave spectrum mask (D3.0)
Device class
Reduction in Power Spectral Density, dBr
4.5MHz Offset
5.0Mhz Offset
5.5MHz Offset
10MHz Offset
15MHz Offset
Class A
-10
-20
-28
-40
Class B
-16
Class C
-26
-32
-50
Class D
-35
-45
-55
-65
Spectrum Mask to fulfill [55+10log(P)] criteria 기준을만족하는
Hanbyeog Cho (ETRI)

8. IEEE 802.11p Spectrum Mask (revision)
March 2008
IEEE p Spectrum Mask (revision)
IEEE p/D1.1
Spectrum Mask using 55+10log(P) , -25dBm
Class
4.5MHz Offset
5.0Mhz Offset
5.5MHz Offset
10MHz Offset
15MHz Offset
Class A
-10
-20
-25
-28
-33
-40
-45
Class B
-16
-35
-43
-55
Class C
-26
-32
-53
-50
-63
Class D
-53.8
-63.8
-65
-73.8
Spectrum Mask to fulfill [55+10log(P)] criteria 기준을만족하는
Hanbyeog Cho (ETRI)

9. Spectrum Mask IEEE 802.11p vs IEEE 802.11p/D1.1 March 2008 Class A
-15
-10 -5 5 10 15
-70
-60
-50
-40
-30
-20
Offset Frequency(MHz)
Power Attenuation(dBr)
Class A
-15
-10 -5 5 10 15
-70
-60
-50
-40
-30
-20
Offset Frequency(MHz)
Power Attenuation(dBr)
Class B
Class C
-15
-10 -5 5 10 15
-70
-60
-50
-40
-30
-20
Offset Frequency(MHz)
Power Attenuation(dBr)
Class D
-15
-10 -5 5 10 15
-70
-60
-50
-40
-30
-20
Offset Frequency(MHz)
Power Attenuation(dBr)
Decrease the inter-channel interference
This contribution suggests an equation to fulfill the FCC regulation
Hanbyeog Cho (ETRI)

10. March 2008
Conclusions
We proposed basic spectrum masks to fulfill the FCC regulation rule. A present WAVE system specification has mismatched spectrum masks. It means that PER(packet error rates) will be increased due to channel interference between adjacent channels.
This presentation is a following work to the presentation by Vinuth Rai &John Kenny last San Francisco meeting (17 July, 2008) .
The proposed spectrum mask will decrease the interference between adjacent channels and the main focus is on the spectrum mask related FCC rule.
Then the spectrum mask should be modified to fulfill [55+10log(P)], -25dBm criteria.
Hanbyeog Cho (ETRI)

11. March 2008
Insert the following text, table, and figures at the end of subclause I.2.3:
For operation in the GHz band in the USA, FCC CFR47 [B8], Section and Section
, the transmitted spectrum shall be as follows and are summarized in Table I.7.
Transmit Spectrum Mask:
The DSRC transmitted spectrum mask is relative to the device class of operation. The power in the transmitted spectrum for all DSRC devices shall be –25 dBm or less within 100 kHz outside all channel and band edges. This will be accomplished by attenuating the transmitted signal 100 kHz outside the channel and band edges by log(P) dB, where P is the total transmitted power in watts. The transmitted spectral density of the transmitted signal for all devices shall fall within the spectral mask, as detailed in Table I.7. The measurements shall be made using a 100 kHz resolution bandwidth and a 30 kHz video bandwidth.
The transmitted spectral mask for class A, B, C, and D devices are shown in Figures. I.3, I.4, I.5, and I.6.
a) For Class A operation using 10 MHz channel spacing, the transmitted spectrum shall have a 0
dBr bandwidth not exceeding 9 MHz, and shall not exceed -10 dBr at 5 MHz frequency offset, -25
dBr at 5.5 MHz frequency offset, -33 dBr at 10 MHz frequency offset, -45 dBr at 15 MHz frequency
offset and above. Figure I.3 shows the spectral mask for Class A operation.
b) For Class B operation using 10 MHz channel spacing, the transmitted spectrum shall have a 0
dBr bandwidth not exceeding 9 MHz, and shall not exceed -16 dBr at 5 MHz frequency offset, -35
dBr at 5.5 MHz frequency offset, -43 dBr at 10 MHz frequency offset, -55 dBr at 15 MHz frequency
offset and above. Figure I.4 shows the spectral mask for Class B operation
c) For Class C operation using 10 MHz channel spacing, the transmitted spectrum shall have a 0
dBr bandwidth not exceeding 9 MHz, and shall not exceed -26 dBr at 5 MHz frequency offset, -45
dBr at 5.5 MHz frequency offset, -53 dBr at 10 MHz frequency offset, -63 dBr at 15 MHz frequency
offset and above. Figure I.5 shows the spectral mask for Class C operation.
d) For Class D operation using 10 MHz channel spacing, the transmitted spectrum shall have a 0
dBr bandwidth not exceeding 9 MHz, and shall not exceed -35 dBr at 5 MHz frequency offset, -53.8
dBr at 5.5 MHz frequency offset, dBr at 10 MHz frequency offset, -73.8
dBr at 15 MHz frequency offset and above. Figure I.6 shows the spectral mask for Class D operation.

12. Table I.7— Class A thru Class D spectrum masks
March 2008
Table I.7— Class A thru Class D spectrum masks
Class
4.5MHz Offset
5.0Mhz Offset
5.5MHz Offset
10MHz Offset
15MHz Offset
Class A
-10
-25
-33
-45
Class B
-16
-35
-43
-55
Class C
-26
-53
-63
Class D
-53.8
-63.8
-73.8
Hanbyeog Cho (ETRI)

13. Spectrum Mask March 2008 Class A Class B
-15
-10 -5 5 10 15
-70
-60
-50
-40
-30
-20
Offset Frequency(MHz)
Power Attenuation(dBr)
Class A
-15
-10 -5 5 10 15
-70
-60
-50
-40
-30
-20
Offset Frequency(MHz)
Power Attenuation(dBr)
Class B
Figure I.3—Class A transmit spectrum mask
Figure I.4—Class B transmit spectrum mask
Class C
-15
-10 -5 5 10 15
-70
-60
-50
-40
-30
-20
Offset Frequency(MHz)
Power Attenuation(dBr)
Class D
-15
-10 -5 5 10 15
-70
-60
-50
-40
-30
-20
Offset Frequency(MHz)
Power Attenuation(dBr)
Decrease the inter-channel interference
This contribution suggests an equation to fulfill the FCC regulation
Figure I.5—Class C transmit spectrum mask
Figure I.6—Class D transmit spectrum mask
Hanbyeog Cho (ETRI)

14. Approve: Disapprove: Abstain: March 2008
Motion (if technical and/or significant):
Move to accept the proposed text , table and figures from above slide 11,12 and 13 and instruct the TGp editor to incorporate the proposed changes.
Motion by: Hanbyeog Cho
Date:
Second: ______________________
Approve:
Disapprove:
Abstain:
Hanbyeog Cho (ETRI)