17-03-2014, 02:35 PM
ERP SERVICE Field Bit Verification
Purpose:
To verify if the device under test (DUT) sets all bit subfields in the DSSS-Long and
Short header SERVICE field appropriately.
Resource Requirements:
• Vector Signal Analyzer (VSA), Rohde & Schwarz FSQ26 or equivalent
• ERP access point/station with external antenna jack
• Associated ERP AP or station with external antenna jack (optional)
• RF Power Splitter, Picosecond 5333 or equivalent
• Controlling Software (Matlab)
Last updated: June 2007
Discussion:
Reference [1] describes the physical layer convergence procedure (PLCP) for Extended Rate
PHYs (ERP) operating in the 2.4 GHz band. Subclause 19.3.2 requires that all ERP stations
support three different preamble and header formats. To provide interoperability with legacy
stations that use direct sequence spread spectrum (DSSS) and complementary code keying
(CCK) modulation, an ERP device must support 1, 2, 5.5, and 11 Mbps data rates conforming to
the Long Preamble and header format described in 19.3.2.1. Likewise, support for the Short
Preamble described in 19.3.2.2 is also mandatory which includes data rates of 2, 5.5, and 11
Mbps. The third is the ERP orthogonal frequency division multiplexing (ERP-OFDM) preamble
and header specified in 19.3.2.3 providing 6, 12, and 24 Mbps data rates.
Procedure:
1. For DUTs that support continuous transmission, configure the DUT to continuously
transmit PSDUs of length ≤ 100 bytes on channel 6 at 1 Mbps using Long Preamble
format. Otherwise, for burst mode traffic, configure the DUT to associate with the link
partner on channel 6 at 1 Mbps using Long Preamble format, and generate continuous
ICMP echo request packets of length 100 bytes, and set the Beacon interval to 100 ms. In
either case, configure operation using ERP-DSSS/CCK modulation
2. Configure the trigger on the VSA to capture an entire packet. Demodulate and decode the
frame.
3. Verify SERVICE field bit values conform to Table 2.
Observable Results:
a. Reserved bits 0, 1, and 4 should always be set to zero.
b. Bit 2 should always be set to one.
c. When non-ERP-PBCC modulation is used, bit 3 should be set to zero. Otherwise, bit 3
should be set to one.
d. Bits 5, 6, and 7 should correctly indicate data field length ambiguities.