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The Hata-SRD variation was developed in CEPT within the Project Team SE24 for studies of Short Range Devices (SRD). The basis for modification was an assumption that although SRD devices are usually operated at low antenna heights (typically person-carried devices, i.e. with antenna height of ca. 1.5 m), but the interference would usually occur at relatively short distances (up to 100 m or so) when direct-Line-of-Sight (LoS) or near-direct-LoS might be assumed. Therefore the Hata-SRD model includes adjusted expression of the parameter b(Hb), which in the standard Hata model would introduce significant additional path loss when transmitter antenna height is much less than 30 m. It was found that this additional loss is not justified in the considered SRD scenarios of short range & direct-LoS communication/coupling. In the SEAMCAT propagation library, the user will find the model under the name “Extend Hata - SRD”
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Figure 473: SEAMCAT Interface to the Extended Hata propagation model (general model on the left) and its adapted version for SRDs (on the right)Anchor F473 F473
{ XE "Propagation model:Extended Hata" }
Table 7879: Description of the Extended Hata and Extended Hata (SRD) modelsAnchor T078T079T078 T079
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