Using the Spectrum Emission Mask Measurement

Using the Spectrum Emission Mask Measurement
Use the Spectrum Emission Mask (SEM) measurement (also sometimes referred to as Conducted Spurious Emissions measurement) to identify and determine the power levels of spurious emissions outside the assigned CDMA channel. The measurement is made at the access network output port or at the repeater RF output port.
The SEM measurement only supports cdma2000, 1xEV-DO, and the W-CDMA UTRA channel standards, covering band classes 0,1,3,4,5,6, and 10. If you enable the SEM measurement using an unsupported channel standard, the limit mask will not be turned on and a message will be displayed telling you that the SEM Measurement does not support your selected channel standard. The table below summarizes supported and unsupported CDMA, 1xEV-DO and W-CDMA channel standards.

Band Class
Band Name (Applies to CDMA and 1xEV-DO Only)
Channel Standard Name (Applies to CDMA and 1xEV-DO Only)
SEM Measurements Supported?

0
800 MHz Band.
North American Cellular CDMA (commonly referred to as, 'Cellular Band")
Yes

1
1900 MHz Band
North American PCS CDMA (commonly referred to as, "PCS").
Yes

2
TACS Band
TACS CDMA
SEM Not Supported

3
JTACS Band
Japan CDMA
Yes

4
Korean PCS Band.
Korean PCS CDMA
Yes

5
450 MHz Band
NMT-450
Yes

6
2 GHz Band
IMT-2000 cdma2000
Yes

7
700 MHz Band:
North American 700 MHz Cellular CDMA
SEM Not Supported

8
1800 MHz Band
1800 MHz CDMA
SEM Not Supported

9
900 MHz Band
900 MHz CDMA
SEM Not Supported

10
Secondary 800 MHz Band
Secondary 800 CDMA
Yes

11
400 MHz European PAMR Band
400 MHz European PAMR
SEM Not Supported

12
800 MHz PAMR Band
800 MHz PAMR
SEM Not Supported

NOTE: 1xEVDO SEM measurements are made under two conditions. These are:

Continuous Data mode, that is, with no idle slots.
Idle mode, that is, with all slots idle except the control channel

NOTE: Your E7495A or E7495B test instrument can only make SEM measurements for the first condition, that is, in Continuous Data mode

To make an SEM measurement, the power level limits at different frequency offsets need to be specified. These power limits vary between different channel standards, but have all been predefined for you. These limits are listed in the two tables below. The first table shows the limits for CDMA and 1xEV-DO standards, and the second shows WCDMA UTRA standards.
For all possible channel standards for which you can make an SEM measurement (see the table above), the power limits have been predefined and will be displayed on the screen as a stepped yellow line. This line is known as the 'mask'. If you attempt to make an SEM measurement for a channel standard that does not support SEM measurements, no mask will be displayed, and the message, "SEM Measurement does not support the selected Channel Standard" will be displayed on the bottom of the test instrument's screen.


Band Class	Band Name (Applies to CDMA and 1xEV-DO Only)	Channel Standard Name (Applies to CDMA and 1xEV-DO Only)	SEM Measurements Supported?
0	800 MHz Band.	North American Cellular CDMA (commonly referred to as, 'Cellular Band")	Yes
1	1900 MHz Band	North American PCS CDMA (commonly referred to as, "PCS").	Yes
2	TACS Band	TACS CDMA	SEM Not Supported
3	JTACS Band	Japan CDMA	Yes
4	Korean PCS Band.	Korean PCS CDMA	Yes
5	450 MHz Band	NMT-450	Yes
6	2 GHz Band	IMT-2000 cdma2000	Yes
7	700 MHz Band:	North American 700 MHz Cellular CDMA	SEM Not Supported
8	1800 MHz Band	1800 MHz CDMA	SEM Not Supported
9	900 MHz Band	900 MHz CDMA	SEM Not Supported
10	Secondary 800 MHz Band	Secondary 800 CDMA	Yes
11	400 MHz European PAMR Band	400 MHz European PAMR	SEM Not Supported
12	800 MHz PAMR Band	800 MHz PAMR	SEM Not Supported