Measurements of Noise in the 2.3-2.5 Ghz Band

Abstract

The frequency range 2.3 – 2.5 GHz includes the band allocated by spectrum management authorities of 2.4 – 2.485 GHz for industrial scientific and medical radio use, the ISM band. Wireless local area networks (WLANs) which are covered by the IEEE 802.11 standard have also been allocated use of this ISM band. As a direct result of this frequency allocation an investigation of background noise and its characterisation to assist the design phase of WLAN systems was required. Characterisation of noise in every possible environment where a WLAN may be required to operate is from a measurement perspective a monumental task which is not realistic. A practical approach of choosing sites where portable radio receivers are likely to be used was adopted. These sites included both indoor and outdoor locations where man-made terrestrial noise sources such as electrical office machinery, factory workshop equipment, electric trains and automobile ignition noise was concentrated.