Mobile Wireless

ABSTRACT

INTRODUCTION

METHODOLOGY

TECHNICAL RESULTS AND ANALYSIS

Design of the Base Transceiver Station (BTS)

Ground Reflection Model

Outdoor Propagation Model by using Okumura Model

Measurements

Analysis

CONCLUSION

OVERVIEW

IMT2000 is a federation of system for third-generation of Mobile Telecommunication which provide

High Speed Access

Support for broadband multimedia services

Universal mobility

ABSTRACT

We need to determine whether the quality of the signal received by the mobile cellular user in Parit Raja, Batu Pahat, Johor is better by doing field measurement on the received power signal by using LTE Spectrum Analyzer and supporting calculation to support the results.

INTRODUCTION

As Telecomm Engineer in FCS Telecommunication Berhad, we were assigned to investigate the quality of power received by the user of the Mobile Cellular Network in Parit Raja, Batu Pahat, Johor.

The spectrum that we need to investigate are for Frequency Division Duplex (FDD) for IMT 2000 as follows :-

a) Lower Band for Digi - 1956MHz to 1980MHz

b) Upper Band for Digi 2155MHz to 2170MHz

Sources SKMM Malaysia

INTRODUCTION

Frequency Spectrum A scientific method of plotting and classifying electromagnetic waves as they occur in space and in the everyday environment

Frequency Division Duplex (FDD) A technique where to separate frequency bands used are used at transmitter and receiver side. FDD is better choice than Time Division Duplex (TDD) for symmetric traffic such as voice applications in broadband wireless networks.

FDD is a technique where the transmitter and receiver operate at different carrier frequencies. For instance, in mobile wireless networks, one block of the electromagnetic spectrum is allocated for uplink, which carries data from mobile phones to a base station.

A triangle wave pictured in the time domain (top) and frequency domain (bottom)

FDD where there are two frequency band assigned, one for downlink and one for uplink. The difference between uplink carrier frequency and downlink carrier frequency is called duplex spacing

INTRODUCTION

Free Space Propagation Model assume a transmit antenna and a received antenna to be located in an otherwise empty environment. Neither absorbing obstacles nor reflecting surface are considered which is in particular, the influence of the earth surface is assume to be entirely absent.

This model is used to predict :- Received signal strength when the transmitter and receiver has

a clear, unobstructed LoS between them

This model assume a transmit antenna and a received antenna to be located in an otherwise

Satellite communication systems and microwave line-of-sight radio links typically undergo free space propagation

x Transmit Antenna

Received Antenna Aperture

Transmit antenna modelled as a point source. Transmit power is spread over the surface area of a hypothetical sphere. The receiver antenna has an aperture A, illustrated in triangle

INTRODUCTION

Base Transceiver Station (BTS) is a piece of equipment that facilitates wireless communication between user equipment (UE) such as mobile phone and a network.

INTRODUCTION

Ground Reflection Model Radio Propagation Model that predicts path loss when the signal received consists of the line of sight component and multipath component formed predominately by a single ground reflected wave.

Outdoor Propagation Model based on systematic interpretation of measurement data obtained in the service area. There are three type of this model, which is

Okumura Model (Which is used in this investigation)

Hata Model

Okumura and Hata Model

2-Ray Ground Reflection diagram including variables for the 2-ray ground reflection propagation algorithm.

METHODOLOGY

Many methodology and finding from this field mainly generated into journal for others to take advantage and improve as upcoming studies. The method use is use to achieve the objective of the project that will accomplish a perfects result. In order to evaluate of the results, the methodology is based on system development life cycle (SDLC), generally three major step which is planning, implementing and analysis.

Planning Measurement Implementation Analysis and

Discussion

METHODOLOGY

This studies used three major steps to implements this task from planning, implementing and analysis. All the methods used for finding and analyzing data regarding of the studies

Planning

Implementing

Analysis

Literature Review

Work Planning

Measurement using LTE

Spectrum Analyzer

Theory Calculation

Analyze the results and

measurement

Discussion and conclusion

Design of Base Transceiver Station (BTS)

UTHM is located in rural area in Johor, call Parit Raja, Batu Pahat. In this area, it still categorized as sub-urban area, which is the user of mobile phone is considering still not many compare to urban area. Due to that, service provider has installed macrocells base station around this area in order to enable mobile user across this area to make a call.

A Macrocells provides the main coverage in a mobile network. The antennas from macrocells are mounted on the ground-based masts, huge towers, rooftops and other existing structures. Macrocell based stations have a typical power output of tens of watts. Tower height for this BTS is about 30m to 35m.

RESULT & ANALYSIS

Example of Macrocell that have been install in rural area

Design of Base Transceiver Station (BTS)

Below is the specification of Macrocells Base Transceiver Station (BTS) and other BTS by using standard that have been use for commonwealth country:-

RESULT & ANALYSIS


The two way ground reflection model is a useful propagation model that is based on geometric optic and considers both the direct path and a ground reflected propagation path between transmitter and receiver. The equation for Ground Reflected Model as below:

Pr d = 22

4

Pr(d) = Received Power

Pt = Transmitted Power

Gt = Transmitter Antenna Gain

Gr = Receiver Antenna Gain

d = T-R separation distance

ht = Transmitter height

hr = Receiver height

RESULT & ANALYSIS


RESULT & ANALYSIS

Term Value Description

Gt 20 db Base Station Antenna, Dual Polarization 1710Mhz

to 2170Mhz.

Pt 300 W Base Station Antenna, Dual Polarization 1710Mhz

to 2170Mhz.

ht 30m Microcell (25Km)

hr 3m 1 - 3 meter

Gr 0.001 W

Ground Reflection Model (calculation)

Gt W = 1 20

10 = 100 W

Pr d = 300 100 0.001 30 2 (3)2

(2400)4

= 300 100 0.001 30 2 (3)2

(2400)4

= 7.324 x 109

Pr d = 10 ( 7.324 x 109) = 81.35

Pr d = 81.35 + 30 = .

RESULT & ANALYSIS

Outdoor Propagation Model by Using Okumura Model

The Okumura Model for urban areas is a radio propagation model that was built using the data collected in the city of Tokyo, Japan. The model is ideal for using in cities with many urban structures but not many tall blocking structures. Okumura model was built into three modes. The ones for urban, sub-urban and open areas. The model for urban areas was built first and used as the base for others. Since Parit Raja located in sub-urban / rural area, this model is suitable to applied on this analysis.

Formula for Okumura Model:

= + ,

RESULT & ANALYSIS


where :

50 : 50th percentile of path loss (i.e median)

: free space propagation pathloss.

, : median attenuation relative to free space

(Can be obtained from Okumuras emperical plots)

: base station antenna height gain factor

: mobile antenna height gain factor

: gain due to type of environment

RESULT & ANALYSIS


It is cover :

Frequency : 1501920 MHz

Mobile station antenna height: between 1 m and 10 m

Base station antenna height: between 30 m and 1000 m

Link distance: between 1 km and 100 km

RESULT & ANALYSIS

Outdoor Propagation Model by Using Okumura Model (Calculation)

50 = + ,

= -130dB + 40dB (-16.48 dB) - (0dB) -10dB

= -83.52dB

The free space path loss is:

= 102

(4)22

= 10

3 108

2170 106

2

(4)2(35 103)2

= 130

RESULT & ANALYSIS


Median attenuation relative to free space:

From the Okumura curves:

Amu (2170 MHz(35 km)) = 40 dB

RESULT & ANALYSIS


Correction factor, , for different types of terrain:

Correction factor, Garea = 10 dB

RESULT & ANALYSIS


Transmitter and receiver gain :

= 20

200= 20

30

200= 16.48

= 10

3= 10

3

3= 0

RESULT & ANALYSIS

Measurements

The Project assignment needs to find International Mobile Telecommunication - 2000 (IMT-2000) Frequencies. The project needs to measure Frequency Division Duplex (FDD) Lower Band (1965 - 1980 MHz) and Upper Band (2125 2170 MHz) spectrum. In the measurement, the frequencies spectrum only for Upper Band is detected. The Lower Band is not detected at UTHM area. The Measurement result for Lower Band is as figure 1 and for Upper Band is as figure 2.

RESULT & ANALYSIS

RESULT & ANALYSIS

Lower Band Spectrum (1965-1980MHz)

Upper Band Spectrum (2155- 2170MHz)

Analysis

The analysis result from the calculation and measurement has some different value. The differences in measurement are happen because of attenuation during transmission propagation from the transmitter (BTS). The Result is as table 1 below.

RESULT & ANALYSIS

Model/Measurement Power Receive (dbM)

Ground Reflected Model -51.35

Okumura Model -83.52

Measurement -50.30

Table 1: Analysis result

This assignment project very helpful for student because its show the student to more understand about the mobile spectrum in UTHM area. This project shows the calculation and the measurement have some differences value. The measurement power receive is lower compare to the calculation, because of losses during propagation from the transmitter (BTS).

The measurement only detected for Upper Band spectrum. The reason, is to make more spectrum efficiency because the number of user in this area. Other than that The DIGI service provider are sharing another provider facilities in certain area.

CONCLUSION

Documents

Mobile Wireless