Introduction

This Annex presents the results of three sharing analyses for the band 5 250-5 350 MHz between the spaceborne active sensors and the high speed WLANs, or RLANs. The first study, given in § 2 of this Annex, uses high performance RLAN (HIPERLAN) type 1 classes B and C and HIPERLAN type 2 characteristics for the RLANs and uses SAR4 characteristics for the SAR. In this study, it is feasible for the indoor only HIPERLAN type 1 class B and HIPERLAN type 2 to share the 5 250- 5 350 MHz band with SAR4, but is not feasible for the HIPERLAN type 1 class C to share the band, nor for any HIPERLAN type designed to be operated outdoors with the technical characteristics assumed in the study.

The second study, as given in § 3 of this Annex, uses three RLAN types, RLAN1, RLAN2, and RLAN3, and uses SAR2, SAR3, and SAR4 characteristics for the SARs. In this study, for the single transmitter deployed outdoors, the RLAN1 high speed WLAN transmitter interference was above the acceptable level for SAR4, the RLAN2 high speed WLAN transmitter interference was above the acceptable levels for both SAR3 and SAR4, and the RLAN3 high speed WLAN transmitter interference was above the acceptable level for SAR4. For indoors/outdoors RLAN deployment, it is feasible for the RLAN1, based on an assumption of only 12 active transmitters per km² within the SAR (footprint) and a single frequency channel for the RLAN1, to share with SAR2, SAR3, and SAR4, but it is not feasible for the RLAN2, based on an assumption of 1 200 active transmitters per office space and 14 channels across a 330 MHz band, to share with SAR2, SAR3, and SAR4. For an indoor deployment and considering the interference from the RLAN3 configuration of high speed WLANs to the SARs, the analysis shows that any surface density less than 37-305 transmitters/km²/channel will yield acceptable interference levels into the SAR, depending on the imaging SAR pixel S/N for an imaging SAR. The anticipated mean density is estimated to 1 200 transmitter/large office area and 250 transmitters/industrial area. The anticipated high density assumes 14 channels, each 23.6 MHz wide, over a 330 MHz band. For interference from the RLAN3 configuration of high speed WLANs to the SARs, the analysis shows that only for a surface density less than 518 to 4 270 transmitters/km² over 14 channels, will local area networks (LANs) yield acceptable interference levels into the SAR. For RLAN3 interference into SAR2 and SAR4, this would correspond to about 3 to 12 large office buildings or 15 to 60 industrial areas within the SAR footprint, depending on the SAR pixel S/N.

The third study, as given in § 4 of this Annex, uses the more critical HIPERLAN type 1 characteristics for the RLANs and uses the altimeter characteristics as given in Table 2 for the altimeter. The radar altimeter operation with a 320 MHz bandwidth around 5.3 GHz is compatible with HIPERLANs.

The fourth study, as given in § 5 of this Annex, uses the HIPERLAN type 2 characteristics for the RLANs and uses the scatterometer characteristics as given in Table 3 for the scatterometer. The scatterometer operation around 5.3 GHz is compatible with HIPERLANs operated indoors.