Ten-Ray Model (Dielectric Canyon)
In Ten rayModel (Dielectric Canyon) an infinite number of rays can be reflected off the building fronts to arrive at the receiver
Ten Ray Model:
- Rays may also be back reflected from buildings behind the transmitter or receiver some of the signal energy is dissipated with each reflection, signal paths corresponding to more than three reflections can be ignored.
- Ten reflection rays closely approximate signal propagation through the dielectric canyon.
- The ten rays incorporate all paths with one, two, or three reflections: specifically, there is the LOS, the ground-reflected (GR), the single-wall (SW) reflected, the double-wall (DW) reflected, the triple-wall (TW) reflected, the wall-ground (WG) reflected and the ground-wall (GW) reflected paths.
Overhead View of the Ten-Ray Model
- For the ten-ray model, the received signal is given by
- where xi denotes the path length of the ith reflected ray, τi = (xi− l)/c, and √Gxi is the product of the transmit and receive antenna gains corresponding to the ith ray.
- If u(t) ≈ u(t − τi)then the received power corresponding to (1) is
- Power falloff with distance in both the ten-ray model for transmit antennas both above and below the building skyline is typically proportional to d-2 even at relatively large distances.
General Ray Tracing:
- This is used to predict the field strength and delay spread for any building configuration and antenna placement.
- In this building database and transmitter (Tx) and receiver (Rx) location relative to building must be specified accurately.
- It explain the basic mechanism of Urban propagation and used to obtain the delay and signal strength information for particular transmitter (Tx) and receiver (Rx)
- The GRT method uses geometrical optics to trace the propagation of the LOS and reflected signal components, as well as signal components from building diffraction and diffuse scattering.
- There is no limit to the number of multipath components at a given receiver location: the strength of each component is derived explicitly based on the building locations and dielectric properties.