Technical White Paper for the EasyRET Antenna Solution

Technical White Paper for the EasyRET Antenna Solution

Author： xingzengwu（193651）

Issue： 01

Date： 2012-08-27

HUAWEI TECHNOLOGIES CO., LTD.

Issue V1.0 (2012-08-27) Huawei Proprietary and Confidential

Copyright © Huawei Technologies Co., Ltd.

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Copyright © Huawei Technologies Co., Ltd. 2012. 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 contract made between Huawei and

the customer. All or part of the products, services and features described in this document may not be

within the purchase scope or the usage scope. Unless otherwise specified in 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 a 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]

http://www.huawei.com/

mailto:[email protected]




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Contents

1 Abstract of the EasyRET Antenna Solution ............................................................................. 3

2 Introduction to Traditional RET Antenna Solutions ............................................................. 4

3 Problems Confronted by Traditional RET Antenna Solutions ............................................ 7

3.1 Complex Installation ........................................................................................................................................ 7

3.2 Complex Commissioning ................................................................................................................................. 8

3.3 High Fault Rate and Poor Reliability Due to a Large Number of Connections................................................ 8

4 EasyRET Antenna Solution ......................................................................................................... 9

4.1 Overview .......................................................................................................................................................... 9

4.2 Advantages ..................................................................................................................................................... 10

5 Conclusion .................................................................................................................................... 15

6 Acronyms and Abbreviations ................................................................................................... 16




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1 Abstract of the EasyRET Antenna Solution

With the coming of the mobile broadband (MBB) Era, radio networks are optimized more and

more frequently, and the antenna optimization cost is higher and higher. Currently, a

traditional remote electrical tilt (RET) antenna is confronted with problems such as frequent

mistakes in manual operations, high installation and maintenance cost, and poor reliability in

long-term operation. The EasyRET antenna solution can effectively resolve these problems.

This solution facilitates installation, maintenance, and usage of the RET antenna; therefore,

the O&M efficiency is improved. The solution has the following features:

Free of configuration

Free of calibration

Free of RCU installation

Free of manual recording of bar codes

High reliability

Excellent performance




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2 Introduction to Traditional RET Antenna Solutions

Based on the category of tilt angles, there are two types of electrical tilt antennas on base

stations.

Mechanical electrical tilt (MET) antenna

The tilt angle of this type of antenna can be adjusted using the following methods:

− Manually adjusting the mechanical gauge to pull the internal phase shifter

− Installing an external remote control unit (RCU) connected to a portable control unit

(PCU) and adjusting the tilt angle using the PCU

Figure 2-1 Shows the solution for manually adjusting the tilt angle of the MET antenna




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Figure 2-2 Shows the solution for adjusting the tilt angle of the MET antenna using the PCU

RET antenna

The network management system (NMS) is adopted to remotely adjust the tilt angle of a

RET antenna. This method allows constant and dynamic adjustment of the tilt angle of

an antenna beam. A site does not need to be powered off during the adjustment, which

enables continuous service provisioning.

A RET antenna is installed vertically. No clearance is required for a tilt angle of the RET

antenna. The installation components are simple and reliable. The monitoring database

stores the current and historical data of antenna beams at each site on the live network to

facilitate remote monitoring and analysis. Currently, RET antennas are preferred, which

improves the operator's operation and maintenance (O&M) efficiency.

Figure 2-3 shows the solution for remotely adjusting the tilt angle of the MET/RET

antenna with an external RCU

Figure 2-3 Solution for remotely adjusting the tilt angle of the MET/RET antenna with an external

RCU




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3 Problems Confronted by Traditional RET Antenna Solutions

3.1 Complex Installation

Installations of traditional RET antenna involves the following steps:

Step 1 Assemble the mounting bracket, and install the jumper and RCU, and provide waterproof

protection to the jumper on the tower.

Step 2 Lift and install the antenna on the tower and set the mechanical tilt angle based on network

planning requirements.

Step 3 Record the RCU serial numbers for each cell.

Step 4 Install the Antenna Interface Standards Group (AISG) cables.

Step 5 Record the site number, sector number, and antenna electrical tilt port mapping each RCU.

Step 6 After the installation, submit the records to network planning and optimization engineers to

prepare for the subsequent remote commissioning.

The installation procedure includes operations on and under the tower, which increases the

duration of base station deployment.




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3.2 Complex Commissioning

Figure 3-1 Process for remote commissioning of a RET antenna

The commissioning is conducted manually. Test engineers must confirm the execution status

and participate in the entire configuration process. The configuration of a single site takes

more than 12 minutes.

3.3 High Fault Rate and Poor Reliability Due to a Large Number of Connections

In a traditional RET antenna solution, multiple connection points exist on the RCUs, smart

Bias-Tee (SBT), AISG cables, and antennas. These connection points are vulnerable to faults.

Statistics of a European operator shows that, inappropriate connections and water ingress

problems occur at 54% surveyed sites and RET connection problems (incorrect installation or

configuration) occur at 27% surveyed sites.

External RCUs must be connected to electrical ports and mechanical ports during installation.

More frequency bands require more complex installation. Network operation records indicate

that most problems related to the electrical tilt are caused by a large number of connections of

external RCUs. The following problems occur frequently:

Improper cable contact caused by incorrect connection

Short circuit resulted from water ingress caused by incorrect cable connection

Damage of mechanical ports caused by collision during connection

Operation failures of mechanical ports due to incorrect installation

If a traditional RET antenna is cascaded, RCU bar codes must be manually and locally

recorded. There is a high probability that incorrect mapping relationship is recorded. As a

result, the tilt angle is incorrectly adjusted, which affects network key performance indicators

(KPIs) and increases maintenance cost.

In addition, the RCU of a traditional RET antenna is exposed for a long time and affected

severely by the environment and climate. Consequently, the antenna has a low reliability.




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4 EasyRET Antenna Solution

4.1 Overview

The EasyRET antenna solution effectively resolves problems confronted by traditional RET

antenna solutions. With comparison to the existing RET solution, the EasyRET solution has

the following characteristics:

The antenna integrates with electrical tilt devices such as the RCU and SBT. The One

Box provides all components of an electrical tilt antenna, reducing the connector

quantity and site installation requirements to the minimum.

An electrical tilt device can be identified remotely, requires no configuration or

calibration on site, and provides accurate phase control. Meanwhile, an electrical tilt

device allows a piece of AISG main equipment to manage multiple electrical tilt units or

allows two pieces of AISG main equipment to manage one or multiple electrical tilt units

respectively.

Figure 4-1 shows the EasyRET solution for remotely adjusting the tilt angle of an electrical

tilt antenna.

Figure 4-1 EasyRET solution for remotely adjusting the tilt angle of an electrical tilt antenna




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4.2 Advantages

The EasyRET antenna solution has the following advantages:

The EasyRET antenna solution reduces jumpers and mechanical connections, improves

the installation efficiency, and reduces the error probability.

Figure 4-2 shows the schematic drawing of the traditional antenna solution with an

external RCU. Figure 4-3 shows the schematic drawing of the EasyRET antenna

solution.

Figure 4-2 Schematic drawing of the traditional antenna solution with an external RCU

Figure 4-3 Schematic drawing of the EasyRET antenna solution




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Components

Number of Components in the Traditional RET Antenna Solution

Number of Components in the EasyRET Antenna Solution

AISG cable 4 1

STMA 1 1

RCU

connector

4 0

AISG

connector

8 2

The EasyRET antenna solution reduces the number of components from 17 in a RET

solution to 4, which facilitates component installation and greatly reduces the number of

connections. A multi-frequency antenna connects to only one ASIG cable with no

mechanical interface exposed. This reduces problems caused by interfaces. Meanwhile,

water ingress problems are greatly reduced owing to the protection provided by the

radome. Onsite operations are reduced and problems or risks caused by mistakes are also

reduced. Figure 4-4 shows the comparison of a traditional RET antenna and an EasyRET

antenna.

Figure 4-4 Comparison of a traditional RET antenna and an EasyRET antenna

The electrical tilt device can be identified remotely without configuration or calibration,

which improves site deployment efficiency.

Before an EasyRET antenna solution is delivered, the electrical tilt components and the

antenna are strictly matched. Meanwhile, related configuration data is loaded and

calibrated. This omits the data configuration and calibration during the installation of a

RET antenna and improves the RET configuration efficiency significantly.

The EasyRET antenna solution adopts the creative Color Coding technology. The RCU

can be identified automatically and remotely and different ports are marked by various

colors and shapes. The EasyRET antenna solution resolves problems caused by multiple

cascaded RCUs in a RET solution, including incorrect configuration, heavy workload

generated from manual bar code recording, and incorrect feeder connections.

The Color Coding technology is defined by the ASIG. Antenna radio frequency (RF)

ports of various frequency bands and types are differentiated by color and shape to




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ensure correct connections of antennas and feeders. Figure 4-5 shows the schematic

drawing of three antenna port types identified using the Color Coding technology.

Figure 4-5 Schematic drawing of three antenna port types identified using the Color Coding

technology

After an EasyRET antenna is powered on, the antenna automatically reports the RCU bar

code to the network management center (MNC). The MNC saves the RCU bar code and

matches the EasyRET antenna with the port and frequency band automatically. If a

frequency band needs to be adjusted, an RCU bar code can be queried from the NMS

directly, which reduces manual recording of RCU bar codes and prevents adjustment

errors caused by incorrect RCU bar codes.

The EasyRET antenna improves reliability.




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The EasyRET antenna resolves reliability problems of a RET antenna. Table 4-1 lists the

comparison between an EasyRET antenna solution and a RET antenna solution from

aspects such as waterproof performance, lightning protection capability, and corrosion

resistance capability.

Table 4-1 Comparison of an EasyRET antenna solution and a RET antenna solution

Traditional RET Antenna Solution

EasyRET Antenna Solution

Waterproof

performance

Waterproof protection is

provided to multiple RCUs

separately.

There are many AISG

interfaces.

Multiple RCUs share the

waterproof protection inside the

same radome.

Only one or two external AISG

interfaces are configured.

Lightning protection

capability

Cables connected to the RCU

are long and the cable

quantity is large. Lightning

may cause failures.

Most cables are short and routed

inside the radome. The cables are

shielded. Failure risks caused by

lightning are low.

Corrosion resistance

capability

The aluminum alloy enclosure

and coating are easily

corroded in salt fog

environments.

The external interfaces are

vulnerable to oxidation and

corrosion.

The glass reinforced radome

reduces corrosion risks.

Few external interfaces are

configured. Therefore, the

corrosion risks are low.

Self-lock function The electric engine may shift

due to external factors, which

leads to an incorrect tilt angle.

As a result, the tilt angle is

adjusted repeatedly and the

workload increases.

In the non-working state, the

self-lock torque of the electric

engine and gearbox ensures that

the antenna tilt angle does not

change due to vibration.

Failure caused by

manual operations

(configuration and

calibration)

The RCU is manually

installed.

Multiple AISG cables are

manually connected.

The RCU bar code and the

mapping section number are

manually recorded.

Configuration data is

manually loaded and the

antenna is manually

calibrated.

The RCU installation is not

required.

Only one or two AISG cables are

connected.

Manual recording of the RCU bar

code is not required.

Configuration and calibration are

not required.

The EasyRET antenna adopts high reliability design and assurance measures to ensure

the product quality and long-term reliability, including:

1. Reliability is ensured using electric engines that have been deployed in batches on the

network, with passing environment tests and EMS tests:




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− MTBF 88,0000 hours (100 years)

− Operating temperature: –40°C to +75°C

− Operating humidity: 15% to 98% no condensation

− Storage temperature: –55°C to +85°C

− Storage humidity: 15% to 98% no condensation

− Ingress protection: IP56 according to IEC 60529

− Salt-Fog durability: 168 hours

2. Driving components that have been deployed in batches on the network are adopted to

ensure high reliability during material selection and manufacturing. For example,

− The driving screw thread pair that is verified in long-term operation is adopted.

− Aluminum alloy components are adopted. Standard fixtures are made of austenitic

stainless steel. Plastic components are produced using long-term verified materials.

− The flame spread rating of a plastic enclosure or plastic components of the equipment

must reach V-1 or above.

− The solution with the electric engine, gearbox, and driving screw thread pair is

adopted to provide the self-lock function. In the non-working state, the self-lock

torque of the electric engine and gearbox ensures that the antenna tilt angle does not

change due to vibration.

− The redundancy design is adopted. Material design and selection must be based on

application scenarios, material hardness (with margin), and reliability.

− The interface is widened for protection. The AISG standard interface is used as the

external interface.

− The product adopts the environment adaptability design.

3. Highly reliable components are used to provide end-to-end reliability design. Reliability

tests and verification tests are conducted to ensure highly reliable components of the

control panel. For example,

− Shielding design: The AISG connector connects to the control panel, which connects

to the electric engine. The AISG shielding cable is grounded at both ends. The control

panel and electric engine are shielded by the enclosure.

− Waterproof/lightning protection/corrosion resistance design of a board: The line

board is painted with conformal coating.

− Cable design: An external cable adopts AISG cable components that meet the EMC,

waterproof/lightning protection/corrosion resistance, safety, and environment

requirements.

− Lightning protection and grounding design: An AISG connector (male or female) is

fixed under the antenna reflector. A shielding cable is grounded at both ends and is

used to connect an AISG connector to a board and a board to an electric engine. The

board enclosure and electric engine driving enclosure connect to the antenna reflector

that is grounded. The lightning protection circuit of the power interface and signal

interface is grounded. The product adopts the environment adaptability design.

4. High-specification PIM design is adopted. The connection part of metal components

must be isolated to prevent direct contact.




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5 Conclusion

The EasyRET antenna solution resolves problems confronted by traditional RET antenna

solutions such as complex installation, long duration, high cost, frequent problems occurrence,

and poor reliability. The EasyRET solution improves the installation accuracy, the

construction efficiency, and the reliability of the antenna system. The EasyRET solution can

effectively avoid high maintenance costs due to secondary site deployment and help operators

reduce the network optimization investment and maintenance cost.




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6 Acronyms and Abbreviations

A

AISG Antenna Interface Standard Group

M

MET Mechanical electrical tilt

MBB Mobile broadband

P

PCU Portable control unit

R

RET Remote electrical tilt

S

SBT Smart Bias-Tee

STMA Smart tower mounted amplifier

Documents

Technical White Paper for the EasyRET Antenna Solution