Basis for requirement specifications - Environmental interference effects on radio coverage


  • Karina Fors
  • Åsa Waern
  • Arwid Komulainen

Publish date: 2015-06-25

Report number: FOI-R--4071--SE

Pages: 27

Written in: Swedish


  • Noise Factor
  • radio
  • radio range
  • background environment
  • platform-noise


This report presents a further work of the project Basis for requirements specification which took place in 2013. In that work we analyzed how disturbances, locally generated on a platform where the radio equipment is installed, affecting a radio receiver uplived noise environment in the form of a noise factor [1]. This report examines how the radio range is affected when the receiver is exposed to varying levels of interference from, on the platform collocated electrical equipment along with interference from the background environment. The range calculations have been made using a link budget for two cases; with and without the interference whose effect on the range we want to study. It is reasonable to assume that the maximum range is calculated for the case when we take into account all disturbances whose levels we cannot easily control. Among them we must include interference from background environment and the receiver's noise level. The levels of these disorders can in principle be affected eg by using a more sensitive radio receiver which has a lower receiver noise or move the platform to other background environments. The performance of a radio system can be difficult to predict because the interference generated on the platform may have a significant impact on the radio system capacity. The report shows examples of the results if the platform interference is assumed to come from co-located electrical equipment. These are assumed to consist of three computers which radiate according with the levels permitted under the MIL-STD-461F, RE102 or on par with a worst-case scenario that has been produced from a number of measured computers. In the case where three COTS computers are co-located with the current radio equipment on the platform strf9040 causes these a range reduction. If these, on the frequency of 49 MHz, rays emission levels on par with:  RE 102: it leads to a range reduction of 12%.  Selected highest emission levels from a number of measured computers leads to a range reduction of 38%. The report concludes with some radio network simulations that show how packet loss increases when we include the effects of background environment and platform disorders. The result shows that when determining requirements of electrical equipment it is important to set the requirements for the entire system. For radio, it means everything from the radio to the cabling and the antenna.