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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 468473: SEAMCAT Interface to the Extended Hata propagation model (general model on the left) and its adapted version for SRDs (on the right)Anchor F468F473F468 F473
{ XE "Propagation model:Extended Hata" }
Table 78: Description of the Extended Hata and Extended Hata (SRD) modelsAnchor T078 T078
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Description | Symbol | Type | Unit | Comments |
Variation |
Variation in path loss takes into account the uncertainty of building design, furniture, room size, etc. | ||||
General environment |
Environment of the propagation: urban, rural, suburban | ||||
Propagation environment |
Environment of the propagation: Below roof, Above roof (used for standard deviation calculations) ONLY USED IF VARIATION OPTION IS CHECKED | |||
Wall loss(indoor - indoor) |
Scalar | dB |
Wall loss std dev (indoor - indoor) |
Scalar | dB |
Loss between adjacent floor |
Scalar | dB |
Empirical parameters: | b |
Size of the room | droom | Scalar | m |
Height of each floor | hfloor | Scalar | m |
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