- Microwaves and wireless simplified / Thomas S. Laverghetta - Details - Trove
- Stella & Rose's Books
- Microwave Journal Releases Comprehensive Microwave Basics Library
- Account Options
A populated area is divided into many small regions called cells. The cells are linked to a central location, called a mobile telephone switching office MTSO , which coordinates all incoming calls. Along with coordinating calls between cell sites, the MTSO also generates time and billing information.
A diagram of a cellular system is shown in Figure 7. The main block, the MTSO, is the control area for the system. It is the unit that connects the caller to the party the caller is trying to contact. If the caller is moving e.
The central office provides the same functionality as the central office in a conventional telephone system, that is, it provides a connection between one phone and another. Because it covers only a small geographical area, the unit is relatively low power. That allows other cells to operate on the same frequency, since the power is low enough such that no interference occurs.
This feature is important since the many cells in an area would interfere with each other if it not for the low power requirements placed on each cell. Thus, many cells can exist in a geographical area, all operating at the same frequency and nicely coexisting. Figure 8 shows a cellular telephone site.
The to MHz frequency band allocated for cellular telephone service ranges from to and to MHz.
For the cellular phone, the lower end to MHz is used for transmitting, while the upper end to MHz is used for receiving. At the base units cell sites , the frequencies are reversed. Within the assigned bands, separate channels are assigned for voice and control, in each band.
Microwaves and wireless simplified / Thomas S. Laverghetta - Details - Trove
The bandwidth for each channel is 30 kHz. A person making a cellular telephone call enters a local seven-digit number or a long-distance digit number. The caller then presses the send button, which transmits data to a channel. This may seem like a time-consuming process, but it is accomplished in a very short period of time.
Stella & Rose's Books
This process is called a handoff, which the user never sees or is even aware of. Most cellular telephones are used in a local area where the phone is originally registered. When it is necessary to operate the phone outside that selected area, the system incorporates a scheme called roaming. Microwave devices. Microwave communication systems. L Microwaves and wireless simplified.
Microwave Journal Releases Comprehensive Microwave Basics Library
Artech House microwave library 1. Microwave devices 2. Microwave communication systems I. Title All rights reserved.
No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the publisher. All terms mentioned in this book that are known to be trademarks or service marks have been appropriately capitalized.
Artech House cannot attest to the accuracy of this information. Use of a term in this book should not be regarded as affecting the validity of any trademark or service mark. Thomas S. Laverghetta is a professor at Purdue University's Fort Wayne campus.
- Peptide Synthesis Protocols.
- Clinical orthoptics.
- Basketball: A Biographical Dictionary;
- Microwave Applications.