Page 313 - Integrated Wireless Propagation Models

I n - B u i l d i n g ( P i c o c e l l ) P r e d i c t i o n M o d e l s 291

The in-building propagation environment is unique and challenging for system
deployment. The Lee model was used to optimize the coverage and interference while
using fine-tuning radio parameters (e.g., antenna types, ERP, and downtilt) to improve
the system performance and to enhance the user's experience. The networks maintained
continuous connectivity with smooth roaming and high data throughput, providing a
great experience for users.

5. . 1 H i ghlight of the Enhanced Lee Model
3
In-building wireless system deployment and performance have their unique challenges,
especially in meeting the high traffic density, high data throughput, and large number
of users in a vertically concentrated system. This is particularly common and challeng­
ing in a skyscraper type of office building in dense urban areas. Due to the complica­
tions of the indoor environment, there is much research literature related to in-building
1 2 0 1
propagation besides the Lee in-building model.4•6, 4• 9•3 •3
This section provides a complete solution for in-building-related propagation. We
first present the measured signal results received inside and between the buildings,
examine the accuracy of the Lee model for the same-floor prediction, and then extend the
Lee model's principle to derive the formulas for interfloor and interbuilding scenarios.
Because Finite-difference time-domain (FDTD) is a popular computational tech­
nique for the electrodynamics modeling. It is considerable easy to understand and easy
to implement in software. The commercial FDTD model and the in-house developed
FDTD models are used to validate the Lee model with the measured data and to make
sure all data and results are valid.

5.3.2 Studying Measured Data in various Cases
Measurements were taken from the first to fifth floors in the north and south wings of a
building in the Republic Polytechnic (RP) in Singapore. The RP building is a 12 floors
high. The north and south wings are of the same shape in both buildings. The dimension
m
of each floor is 31, 8.4, and 2.5 i n length, width, and height, respectively. Figure 5.3.2.0.1
shows a picture of the buildings.

FIGURE 5.3.2.0.1 Picture of the buildings.