 the physical site survey can include specific customer premises equipment (CPE) siting, as well as cable routing and other needs such as lightning protection in exposed locations. RF Site Survey This part of the site survey will assess the RF environment in which subscriber stations will have to operate in terms of potential sources of noise and interference. With this objective in mind, the survey should ideally be conducted with an antenna similar to the CPE equipment that will be installed on the subscriber's premises. An RF site survey is conducted using a spectrum analyser, which will identify wireless transmissions in the target area and in the frequency range of interest. An example of a spectrum analyser display, showing vector analysis of an OFDM signal, is shown in Figure 13-2. The signal strength, direction and polarisation of any signals strong enough to interfere with the network should be recorded, as well as the noise floor (see the Section "Receiver Noise Floor, p. 110"). Spectrum analysis software is also available to run on a desktop or laptop computer and will analyse the signal received from a PCI or PC card receiver equipped with an external antenna. Chapter Thirteen Agilent 89600 Vector Signal Analyzer Control Source Input TestSetup MeasSetup Display Trace Markers Utilities Grid 2x2 Color Normal A: Strm1 OFDM Meas Strm2 OFDM Meas Const Const -1.25 -1.25 -1.722 1.7225 -1.722 1.7225 RBW: 312.5 L kHz TimeLen 8 Sym RBW: 312.5kHz TimeLen 8 Sym B: Strm1 OFDM Eir Vect Spectrum D: OFDM Data Burst Info ModF Fmt Len(sym) Pwr(dBm) EVM(dB) L-STF -5.5788 HT-LTF -5.5601 HT-SIG -5.8612 LinMag HT-LTF -5.4579 HT Data 64QAM -5.5901 -39.685 Total -5.6107 -39.685 HT-SIG CRCPassed carrier Stop 58 carrier RBW: 312.5kHz TimeLen 8 Sym Figure 13-2: Spectrum Analysis Software Display From Agilent (Courtesy of Agilent Technologies Inc.) The results of the RF site survey will be important considerations in the technical design of the MAN, and may impact on aspects such as frequency band selection and base station equi