125278321 5 Ways of Increasing the Capacity of Cellular System
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Transcript of 125278321 5 Ways of Increasing the Capacity of Cellular System
5 ways of increasing the Capacity of cellular system?
Electronics Engineering Questions
Answers.com > Wiki Answers > Categories > Technology > Engineering > Electronics Engineering
3.7. Improving Coverage and Capacity in Cellular Systems
As the demand for wireless service increases, the number of channels assigned to a cell eventually
becomes insufficient to support the required number of users. At this point, cellular design
techniques are needed to provide more channels per unit coverage area. Techniques such as cell
splitting, sectoring, and coverage zone approaches are used in practice to expand the capacity of
cellular systems. Cell splitting allows an orderly growth of the cellular system. Sectoring uses
directional antennas to further control the interference and frequency reuse of channels. The zone
microcell concept distributes the coverage of a cell and extends the cell boundary to hard-to-reach
places. While cell splitting increases the number of base stations in order to increase capacity,
sectoring and zone microcells rely on base station antenna placements to improve capacity by
reducing co-channel interference. Cell splitting and zone microcell techniques do not suffer the
trunking inefficiencies experienced by sectored cells, and enable the base station to oversee all
handoff chores related to the microcells, thus reducing the computational load at the MSC. These
three popular capacity improvement techniques will be explained in detail.
3.7.1. Cell Splitting
Cell splitting is the process of subdividing a congested cell into smaller cells, each with its own base
station and a corresponding reduction in antenna height and transmitter power. Cell splitting
increases the capacity of a cellular system since it increases the number of times that channels are
reused. By defining new cells which have a smaller radius than the original cells and by installing
these smaller cells (called microcells) between the existing cells, capacity increases due to the
additional number of channels per unit area.
Best Answer
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Increasing Channel Capacity
Adding new channels: Typically, when a system is set up in a region, not all of the channels are used,
and growth and expansion can be managed in an orderly fashion by adding new channels.
Frequency borrowing: In the simplest case, frequencies are taken from adjacent cells by congested
cells. The frequencies can also be assigned to cells dynamically.
Cell splitting: In practice, the distribution of traffic and topographic features is not uniform, and this
presents opportunities of capacity increase. Cells in areas of high usage can be split into smaller
cells.
Cell sectoring: With cell sectoring, a cell is divided into a number of wedge-shaped sectors, each with
its own set of channels, typically 3 or 6 sectors per cell. Each sector is assigned a separate subset of
the cell's channels, and directional antennas at the base station are used to focus on each sector.
Microcells: As cells become smaller, antennas move from the tops of tall buildings or hills, to the
tops of small buildings or the sides of large buildings, and finally to lamp posts, where they form
microcells. Each decrease in cell size is accompanied by a reduction in the radiated power levels
from the base stations and the mobile units. Microcells are useful in city streets in congested areas,
along highways, and inside large public buildings.
JDK 7 the Java Development Kit 7 is the latest version of JDK. JDK 7 has lot of
enhancements and features as listed below:
Swing Advancements: In JDK 7, a number of swing components like JLayer class,
nimbus look and feel, heavy and light weight components etc. have been added.
Concurrency Efficacies: In JDK 7, an executor interface has been designed to run
proficiently a bulky number of jobs by worker threads.
JVM Support: In JDK 7, JVM can support languages other than java.
Garbage first collector: In JDK 7, a server side garbage collector known as garbage
first collector was introduced to enhance real time portability.
Networking Enhancements: In JDK 7, URLclassloader, close method has been
included; this can enable extraordinary performance network connections.
Security: New features like elliptic curve cryptography, certpath algorithm disabling
and others have been included in JDK 7 for security purpose.
Varargs: In JDK 7, compiler warnings and errors are upgraded by using Varargs.
Customer JRE Competences: Rich internet applications are embedded in JDK 7
which enables client feasibility.
What are the components of JDK?
Components of JDK (Java Development Kit) are:
Java Compiler – Java Compiler is used to compile java files. Java Compiler
component of JDK (Java Development Kit) is accessed using “javac” command.
Java Interpreter – Java Interpreter is used to interpret the java files that are compiled
by Java Compiler. Java Interpreter component of JDK (Java Development Kit) is
accessed using “java” command.
Java Disassembler - Java Disassembler is used to disassemble Java class file. Java
Disassembler component of JDK (Java Development Kit) is accessed using “javap”
command.
Java Header File Generator - Java Header File Generator is used to generate C
language header files and source files to implement the native methods. Java Header
File Generator component of JDK (Java Development Kit) is accessed using “javah”
command.
Java Documentation – Java Documentation is required for easy maintenance of
code. Java Documentation component of JDK (Java Development Kit) is accessed
using “javadoc” command.
Java Debugger – Java Debugger is used to debug the java files. Java Debugger
component of JDK (Java Development Kit) is accessed using “jdb” command.
Java Applet Viewer – Java Applet Viewer is used to view the Java Applets. Java
Applet Viewer component of JDK (Java Development Kit) is accessed using
“appletviewer” command.
Graphics
CSE5280 Computer Graphics
Chapter #2 Solutions
2-1 List the operating characteristics for the following display technologies: raster refresh
systems, vector refresh systems, plasma panels, and LCD's.
answer: Read Sections 2-1 through sections 2-3 in your textbook. From reading, basically,
you need to understand the following concepts in these sections. These include, refresh
systems, frame (display) buffer, raster displays, resolution, refresh display files, passive
matrix, active matrix, and run-length encoding.
2-4 Consider two raster systems with the resolutions of 640x480, 1280x1024, and
2560x2048.
a) What size frame buffer (in butes) is needed for each of these systems to store 12
bits/pixel? How much storage is required for each system if 24 bits per pixel are to be stored?
Frame-buffer size for each of the systems is
640 × 480 × 12 bits ÷ 8 bits per byte = 450 KB
1280 × 1024 × 12 bits ÷ 8 bits per byte = 1920 KB
2560 × 2048 × 12 bits ÷ 8 bits per byte = 7680 KB
For 24 bits of storage per pixel, each of the above values is doubled.
2-5 Suppose an RGB raster system is to be designed using an 8 inch x 10 inch screen with a
resolution of 100 pixels per inch n each direction. If we want to store 6 bits/pixel in the frame
buffer, how much storage (in bytes) do we need for the frame buffer?
Storage needed for the frame buffer is
(8 inch x 100 pixels/inch) × (10 inch x 100 pixels/inch) × 6 bits ÷ 8 bits per byte ≈ 486 KB
2-7 Suppose we have a computer with 32 bits/word and a transfer rate of 1 million
instructions/second (MIP). How long would it take to fill the frame buffer of a 300 dpi laser
printer with a page size of 8.5 inches x 11 inches?
Total bits in the printer frame buffer is
8.5 × 11 × 300**2 ≈ 8.4 × 10**6 bits Therefore, loading time is
(8.4 × 10**6 bits) / (32 × 10**6 bps) ≈ 0.263 sec
2-10 How much time is spent scanning across each row of pixels during screen refresh on a
raster system with a resolution of 1280 x 1024 and a refresh rate of 60 frames/second?
The scan rate for each pixel row is
60 frames/sec × 1024 lines/frame = 61, 440 lines/sec
And the scan time is approximately 16.3 microseconds per scan line. (Scan time per
frame is 1/60 sec, or approximately 16.7 milliseconds.)
2-19 Explain the differences between the OpenGL core library, the OpenGL Utility, and the
OpenGL Utility Toolkit?
The OpenGL core library contains hardware-independent functions, such as those for
specifying primitives, attributes, geometric transformations, and three-dimensional viewing
parameters. The GLU library contains functions for some other, more specialized
operations, such as quadric-surface generation, B-spline surface generation, surface texture
mapping, two-dimensional viewing, and some three-dimensional viewing operations.
The GLUT library primarily provides hardware-dependent functions, such as those for
display-window management and for interacting with input devices, but it also contains
functions for generating various plane-surface, quadric-surface, and cubic-surface solids,
such as a cube, sphere, cone, or teapot.
2-21 List the statements needed to set up an OpenGL display window whose lower-right
corner is at pixel position (200, 200) with a window width of 100 pixels and a height of 75
pixels?
The GL Utility graphics calls include:
glutInitWindowPosition (100, 125);
glutInitWindowSize (100, 75);
Description
Write a java application that will draw the largest possible rectangle in a canvas container.
Define a frame containing the drawable canvas container with the size of 200 W X 100 H
pixels. Use the color red to distinguish the rectangle from the frame border. In the center of
the canvas draw the width and height values of the rectangle drawn.
Good luck – solution in downloads