User's Manual

Title: SOP Concentrator Installation

Doc. Number: XX-XXXX Revision: 01 Page 4 of 18

(i) Systems operating in the 2400-2483.5 MHz band that are used exclusively for fixed, point-to-point

operations may employ transmitting antennas with directional gain greater than 6 dBi provided the maximum

peak output power of the intentional radiator is reduced by 1 dB for every 3 dB that the directional gain of the

antenna exceeds 6 dBi.

(ii) Systems operating in the 5725-5850 MHz band that are used exclusively for fixed, point-to-point

operations may employ transmitting antennas with directional gain greater than 6 dBi without any

corresponding reduction in transmitter peak output power.

(iii) Fixed, point-to-point operation, as used in paragraphs (b)(3)(i) and (b)(3)(ii) of this section, excludes the

use of point-to-multipoint systems, omnidirectional applications, and multiple co-located intentional radiators

transmitting the same information. The operator of the spread spectrum intentional radiator or, if the

equipment is professionally installed, the installer is responsible for ensuring that the system is used

exclusively for fixed, point-to-point operations. The instruction manual furnished with the intentional radiator

shall contain language in the installation instructions informing the operator and the installer of this

responsibility.

(4) Systems operating under the provisions of this section shall be operated in a manner that ensures that

the public is not exposed to radio frequency energy levels in excess of the Commission's guidelines.

operating, the radio frequency power that is produced by the intentional radiator shall be at least 20 dB

below that in the 100 kHz bandwidth within the band that contains the highest level of the desired power,

based on either an RF conducted or a radiated measurement. Attenuation below the general limits specified

in Sec. 15.209(a) is not required. In addition, radiated emissions which fall in the restricted bands, as defined

in Sec. 15.205(a), must also comply with the radiated emission limits specified in Sec. 15.209(a)

(d) For direct sequence systems, the peak power spectral density conducted from the intentional radiator to

the antenna shall not be greater than 8 dBm in any 3 kHz band during any time interval of continuous

transmission. (e) The processing gain of a direct sequence system shall be at least 10 dB. The processing

gain represents the improvement to the received signal-to-noise ratio, after filtering to the information

bandwidth, from the spreading/despreading function. The processing gain may be determined using one of

the following methods:

(1) As measured at the demodulated output of the receiver: the ratio in dB of the signal-to-noise ratio with the

system spreading code turned off to the signal-to-noise ratio with the system spreading code turned on.

(2) As measured using the CW jamming margin method: a signal generator is stepped in 50 kHz increments

across the passband of the system, recording at each point the generator level required to produce the

recommended Bit Error Rate (BER). This level is the jammer level. The output power of the intentional

radiator is measured at the same point. The jammer to signal ratio (J/S) is then calculated, discarding the

worst 20% of the J/S data points. The lowest remaining J/S ratio is used to calculate the processing gain, as

follows: Gp = (S/N) o + Mj + Lsys, where Gp = processing gain of the system, (S/N) o = signal to noise ratio

required for the chosen BER, Mj = J/S ratio, and Lsys = system losses. Note that total losses in a system,

including intentional radiator and receiver, should be assumed to be no more than 2 dB.

(f) Hybrid systems that employ a combination of both direct sequence and frequency hopping modulation

techniques shall achieve a processing gain of at least 17 dB from the combined techniques. The frequency

hopping operation of the hybrid system, with the direct sequence operation turned off, shall have an average

time of occupancy on any frequency not to exceed 0.4 seconds within a time period in seconds equal to the

number of hopping frequencies employed multiplied by 0.4. The direct sequence operation of the hybrid

system, with the frequency hopping operation turned off, shall comply with the power density requirements of

paragraph (d) of this section.