Doc. code
CDMA VSWR Detection White Paper Issue
Issue 1.0
Date
2013-07-03
HUAWEI TECHNOLOGIES CO., LTD.
CDMA SWR Detection White Paper
Copyright © Huawei Technologies Co., Ltd. 2009. All rights reserved. No part of this document may be reproduced or transmitted in any form or by any means without prior written consent of Huawei Technologies Co., Ltd.
Trademarks and Permissions and other Huawei trademarks are trademarks of Huawei Technologies Co., Ltd. All other trademarks and trade names mentioned in this document are the property of their respective holders.
Notice The purchased products, services and features are stipulated by the commercial contract made between Huawei and the customer. All or partial products, services and features described in this document may not be within the purchased scope or the usage scope. Unless otherwise agreed by the contract, all statements, information, and recommendations in this document are provided “AS IS” without warranties, guarantees or representations of any kind, either express or implied. The information in this document is subject to change without notice. Every effort has been made in the preparation of this document to ensure accuracy of the contents, but all statements, information, and recommendations in this document do not constitute the warranty of any kind, express or implied.
Huawei Technologies Co., Ltd. Address:
Huawei Industrial Base Bantian, Longgang Shenzhen 518129 People's Republic of China
Website:
http://www.huawei.com
Email:
[email protected]
Issue 1.0 (2013-07-03)
Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.
Page 2 of 11
CDMA SWR Detection White Paper
Contents 1 Executive Summary......................................................................4 2 Introduction................................................................................. 5 3 Solution....................................................................................... 6 3.1 VSWR Inquiry Process............................................................................................................................................7 3.2 User Interaction Interface........................................................................................................................................7
4 Conclusion................................................................................. 11
Issue 1.0 (2013-07-03)
Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.
Page 3 of 11
CDMA SWR Detection White Paper
1
Executive Summary
Previously, when the BTS transmission is faulty and the quality of the network is affected, engineers are required to troubleshoot the VSWR problem at the site using a measurement device. Huawei provides a function of remotely obtaining a precise VSWR, which replaces the local test of the SITEMASTER. This reduces the cost of the device, manpower, network construction, and maintenance. Thus, operators' competitive edge is built.
Issue 1.0 (2013-07-03)
Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.
Page 4 of 11
CDMA SWR Detection White Paper
2
Introduction
VSWR or SWR is short for Voltage Standing Wave Ratio. Because of different media, part of the electromagnetic energy is reflected when the electromagnetic wave is transmitted from medium A to medium B. Then, the moving standing wave forms in area A. The VSWR is the ratio between the moving standing wave voltage peak value and the voltage bottom value. The ratio is calculated through the module value of the reflection coefficient. VSWR = (1 + reflection coefficient module)/(1 - reflection coefficient module) From the perspective of the energy transmission, the ideal VSWR is 1:1, which is the transmission state of the moving standing wave. In such a case, resistance compatibility exists in the transmission cable. The worst VSWR is infinite. The module of the reflection coefficient is 1, which is the absolute standing wave state. In such a case, full reflection exists and no energy is transmitted. Therefore, the higher the VSWR is, the larger the reflection power is, and the lower the transmission efficiency is. In radio communications, because of the resistance incompatibility between the antenna and the feeder, or the antenna and the transceiver, the high frequency energy's reflection occurs. Then the reflection part together with the forward part forms the standing wave. The ratio between the voltage peak value and the voltage bottom value in adjacent voltages is called VSWR. If the VSWR is excessively high, the transmission distance is shortened. In addition, when the energy is reflected to the power amplifier of the transceiver, the power amplifier pipe is subject to damage. Then the operation of the communications system is affected.
Issue 1.0 (2013-07-03)
Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.
Page 5 of 11
CDMA SWR Detection White Paper
3
Solution
Previously, when the BTS transmission is faulty and the quality of the network is affected, engineers are required to troubleshoot the VSWR problem at the site using a measurement device (the SITEMASTER, locate the VSWR problem). Huawei provides a function to remotely obtain a precise VSWR. This reduces the cost of the device, manpower, network construction, and maintenance, which enhances the operators' market competitiveness. In addition, this enables the network management center to accurately query the VSWR of a BTS. The precision of the VSWR within 1.4 is ±0.2. Therefore, this function replaces the local test of the SITEMASTER.
Issue 1.0 (2013-07-03)
Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.
Page 6 of 11
CDMA SWR Detection White Paper
3.1 VSWR Inquiry Process
3.2 User Interaction Interface The M2000 client provides the function of VSWR precision threshold customization. The function consists of two standardized grades: grade one is from 1.50 to 1.80 (≥ 1.50 and < 1.80); grade two is above 1.80 (≥ 1.80). The following figures show the user interface of M2000.
Issue 1.0 (2013-07-03)
Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.
Page 7 of 11
CDMA SWR Detection White Paper
Figure 1.1 M2000 node
Figure 1.2 Threshold settings interface (For details, see PRS, can be reused)
Issue 1.0 (2013-07-03)
Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.
Page 8 of 11
CDMA SWR Detection White Paper
Figure 1.3 Condition settings of the threshold
Issue 1.0 (2013-07-03)
Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.
Page 9 of 11
CDMA SWR Detection White Paper
Figure 1.4 Color and background settings of the threshold
Figure 1.5 VSWR inquiry result interface
Issue 1.0 (2013-07-03)
Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.
Page 10 of 11
CDMA SWR Detection White Paper
4
Conclusion
This chapter describes application scenarios of the VSWR inquiry function. During the initial stage of the site construction, to provide accurate test results, the VSWR inquiry function is used by the GTS engineers to evaluate the project quality of the construction partner. During the entire network delivery, to provide accurate test results, the VSWR inquiry function is used by the customer to evaluate the project quality of Huawei. During the routine maintenance, the VSWR inquiry function serves as a VSWR alarm function. Accurate test results are not required. If the VSWR precision alarm is generated, local site maintenance is required. The VSWR detection function provided by Huawei reduces the network construction and maintenance costs for the operators, thus reducing the CAPAX and OPEX of operators and promoting operators' competitiveness.
Issue 1.0 (2013-07-03)
Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.
Page 11 of 11