4RF Aprisa SR User Manual

Rhein Tech Laboratories, Inc.	Client: 4RF Communications
360 Herndon Parkway	Model: Aprisa SR SRN400-000
Suite 1400	FCC ID: UIPSRN0400012A
Herndon, VA 20170	Standards: FCC Part 90
http://www.rheintech.com	Report #: 2011198
Appendix J: Manual
Please refer to the following pages.

Page 34 of 40

November 2011

Version 1.3.4a

| 1

Copyright

Copyright © 2011 4RF Communications Ltd. All rights reserved.

This document is protected by copyright belonging to 4RF Communications Ltd and may not be reproduced or republished in whole or part in any form without the prior written permission of 4RF Communications Ltd.

Trademarks

Aprisa and the 4RF logo are trademarks of 4RF Communications Limited.

Windows is a registered trademark of Microsoft Corporation in the United States and other countries. Java and all Java-related trademarks are trademarks or registered trademarks of Sun Microsystems, Inc. in the United States and other countries. All other marks are the property of their respective owners.

Disclaimer

Although every precaution has been taken preparing this information, 4RF Communications Ltd assumes no liability for errors and omissions, or any damages resulting from use of this information. This document or the equipment may change, without notice, in the interests of improving the product.

RoHS and WEEE compliance

The Aprisa SR is fully compliant with the European Commission’s RoHS (Restriction of Certain Hazardous Substances in Electrical and Electronic Equipment) and WEEE (Waste Electrical and Electronic Equipment) environmental directives.

Restriction of hazardous substances (RoHS)

The RoHS Directive prohibits the sale in the European Union of electronic equipment containing these hazardous substances: lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyls (PBBs), and polybrominated diphenyl ethers (PBDEs).

4RF Communications has worked with its component suppliers to ensure compliance with the RoHS Directive which came into effect on the 1st July 2006.

End-of-life recycling programme (WEEE)

The WEEE Directive concerns the recovery, reuse, and recycling of electronic and electrical equipment. Under the Directive, used equipment must be marked, collected separately, and disposed of properly.

4RF Communications has instigated a programme to manage the reuse, recycling, and recovery of waste in an environmentally safe manner using processes that comply with the WEEE Directive (EU Waste Electrical and Electronic Equipment 2002/96/EC).

4RF Communications invites questions from customers and partners on its environmental programmes and compliance with the European Commission’s Directives ([e-mail]).

Aprisa SR User Manual

2 |

Compliance General

The Aprisa SR digital radio predominantly operates within frequency bands that require a site license be issued by the radio regulatory authority with jurisdiction over the territory in which the equipment is being operated.

It is the responsibility of the user, before operating the equipment, to ensure that where required the appropriate license has been granted and all conditions attendant to that license have been met.

Changes or modifications not approved by the party responsible for compliance could void the user’s authority to operate the equipment.

Equipment authorizations sought by 4RF Communications are based on the Aprisa SR radio equipment being installed at a fixed location and operated in point-to-multipoint or point-to-point mode within the environmental profile defined by EN 300 019, Class 3.4. Operation outside these criteria may invalidate the authorizations and / or license conditions.

The term ‘Radio’ with reference to the Aprisa SR User Manual, is a generic term for one end station of a point-to-multipoint Aprisa SR network and does not confer any rights to connect to any public network or to operate the equipment within any territory.

Compliance ETSI

The Aprisa SR radio is designed to comply with the European Telecommunications Standards Institute (ETSI) specifications as follows:

Radio performance	EN 300 113-2
EMC	EN 301 489 Parts 1 & 5
Environmental	EN 300 019, Class 3.4
Safety	EN 60950-1:2006
Frequency band	Channel size	Power input		Notified
				body
136-174 MHz	12.5 kHz, 25 kHz	12	VDC
400-470 MHz	12.5 kHz, 25 kHz	12	VDC

Aprisa SR User Manual

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RF Exposure Warning

WARNING:

The installer and / or user of Aprisa SR radios shall ensure that a separation distance as given in the following table is maintained between the main axis of the terminal’s antenna and the body of the user or nearby persons.

Minimum separation distances given are based on the maximum values of the following methodologies:

1.Maximum Permissible Exposure non-occupational limit (B or general public) of

47 CFR 1.1310 and the methodology of FCC’s OST/OET Bulletin number 65.

2.Reference levels as given in Annex III, European Directive on the limitation of exposure of the general public to electromagnetic fields (0 Hz to 300 GHz) (1999/519/EC). These distances will ensure indirect compliance with the requirements of EN 50385:2002.

Frequency (MHz)	Maximum Power	Maximum Antenna	Minimum Separation
	(dBm)	Gain (dBi)	Distance
			(m)
136	+ 37	15	2.5
174	+ 37	15	2.5
330	+ 37	15	2.5
400	+ 37	15	2.5
470	+ 37	15	2.3
520	+ 37	15	2.2
850	+ 37	28	7.7
960	+ 37	28	7.2

Aprisa SR User Manual

		Contents | 5
Contents
1.	Getting Started ..........................................................................	11
2.	Introduction..............................................................................	13
	About This Manual...............................................................................	13
	What It Covers ............................................................................	13
	Who Should Read It ......................................................................	13
	Contact Us.................................................................................	13
	What's in the Box ................................................................................	13
	Aprisa SR Accessory Kit ..................................................................	14
	Aprisa SR CD Contents ...................................................................	14
	Software ............................................................................	14
	Documentation ....................................................................	14
3.	About the Radio .........................................................................	15
	The 4RF Aprisa SR Radio........................................................................	15
	Product Overview ...............................................................................	16
	Network Coverage and Capacity .......................................................	16
	Remote Messaging........................................................................	16
	Repeater Messaging ......................................................................	17
	Product Features ................................................................................	18
	Functions ..................................................................................	18
	Performance ..............................................................................	18
	Usability ...................................................................................	18
	Architecture...............................................................................	19
	Product Operation.................................................................	19
	Physical Layer.............................................................................	19
	Data Link Layer / MAC layer ............................................................	19
	Channel access.....................................................................	19
	Hop by Hop Transmission.........................................................	20
	Network Layer ............................................................................	21
	Packet Routing.....................................................................	21
	Security ...........................................................................................	22
	Interfaces.........................................................................................	23
	Antenna Interface ........................................................................	23
	Ethernet Interface .......................................................................	23
	USB Interfaces ............................................................................	23
	RS-232 Interface..........................................................................	23
	Front Panel Connections .......................................................................	24
	LED Display Panel ...............................................................................	25
	Normal Operation ........................................................................	25
	Software Upgrade ........................................................................	25
	Test Mode .................................................................................	26

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6 | Contents

4. Product Options .........................................................................	27
Dual Antenna Port...............................................................................	27
Protected Station ...............................................................................	28
Operation..................................................................................	28
Configuration Management ......................................................	29
Switch Over ...............................................................................	29
Switching Criteria .................................................................	29
Hardware Manual Lock............................................................	30
Remote Control ....................................................................	30
Installation ................................................................................	31
Mounting ............................................................................	31
Cabling ..............................................................................	31
Power ...............................................................................	31
Maintenance ..............................................................................	32
Changing the Protected Station IP Addresses .................................	32
Protected Station Software Upgrade ...........................................	32
Replacing a Protected Station Faulty Radio ...................................	33
Setting the Software Manual Lock ..............................................	33
Spares ......................................................................................	34
Replacing a Faulty Protection Switch ..........................................	34
Data Driven Protected Station.................................................................	35
Operation..................................................................................	35
Switch Over ........................................................................	36
Configuration Management ......................................................	36
Installation ................................................................................	37
Mounting ............................................................................	37
Cabling ..............................................................................	38
Power ...............................................................................	38

5. Implementing the Network ...........................................................	39
Network Topologies .............................................................................	39
Point-To-Point Network ..........................................................	39
Point-to-Multipoint Network .....................................................	39
Point-to-Multipoint with Repeater 1............................................	39
Point-to-Multipoint with Repeater 2............................................	39
Initial Network Deployment ...................................................................	40
Install the Base Station ..................................................................	40
Installing the Remote Stations .........................................................	40
Install a Repeater Station ...............................................................	40
Network Changes ................................................................................	41
Adding a Repeater Station ..............................................................	41
Adding a Remote Station ................................................................	41

Aprisa SR User Manual

		Contents | 7
6.	Preparation...............................................................................	43
	Bench Setup......................................................................................	43
	Path Planning ....................................................................................	44
	Antenna Selection and Siting ...........................................................	44
	Base or Repeater Station.........................................................	44
	Remote Station ....................................................................	45
	Antenna Siting .....................................................................	46
	Coaxial Feeder Cables ...................................................................	47
	Linking System Plan ......................................................................	47
	Site Requirements...............................................................................	48
	Power Supply..............................................................................	48
	Equipment Cooling .......................................................................	48
	Earthing and Lightning Protection .....................................................	49
	Feeder Earthing....................................................................	49
	Radio Earthing .....................................................................	49
7.	Installing the Radio .....................................................................	50
	Mounting..........................................................................................	50
	Required Tools ............................................................................	50
	DIN Rail Mounting ........................................................................	51
	Rack Shelf Mounting .....................................................................	52
	Wall Mounting.............................................................................	52
	Installing the Antenna and Feeder Cable ....................................................	53
	Connecting the Power Supply .................................................................	54
	External Power Supplies.................................................................	54
	Spare Fuses................................................................................	55
	Additional Spare Fuses............................................................	56

Aprisa SR User Manual

8 | Contents

8. Managing the Radio.....................................................................	57
SuperVisor ........................................................................................	57
Connecting to SuperVisor ...............................................................	57
Management PC Connection .....................................................	58
PC Settings for SuperVisor .......................................................	59
Login to SuperVisor................................................................	63
Logout of SuperVisor ..............................................................	64
SuperVisor Screen Layout ........................................................	65
SuperVisor Menu ..........................................................................	67
SuperVisor Menu Access ..........................................................	68
SuperVisor Menu Items............................................................	69
Network Status ....................................................................	69
Terminal ............................................................................	70
Radio ................................................................................	78
Ethernet ............................................................................	92
Security ...........................................................................	100
Maintenance......................................................................	108
Events .............................................................................	124
Parameters .......................................................................	130
Command Line Interface .....................................................................	131
Connecting to the Management Port ................................................	131
CLI Commands ..........................................................................	134
Viewing the CLI Terminal Summary...........................................	136
Changing the Radio IP Address with the CLI .................................	136
In-Service Commissioning ....................................................................	137
Before You Start...............................................................................	137
What You Will Need ....................................................................	137
Antenna Alignment............................................................................	138
Aligning the Antennas .................................................................	138

9. Maintenance ............................................................................	139
Radio Software Upgrade......................................................................	140
Upgrade Process ........................................................................	140
Software Downgrade...................................................................	141

10. Interface Connections ................................................................	142
RJ-45 Connector Pin Assignments...........................................................	142
Ethernet Interface Connections .............................................................	142
RS-232 Serial Interface Connections........................................................	143
Protection Switch Remote Control Connections ..........................................	143

11. Alarm Types and Sources ............................................................	144
Alarm Types....................................................................................	144
Alarm Events ............................................................................	144
Informational Events...................................................................	147

Aprisa SR User Manual

		Contents | 9
12.	Specifications ...........................................................................	148
	RF Specifications ..............................................................................	148
	ETSI Compliant..........................................................................	148
	Frequency Bands ................................................................	148
	Channel Sizes ....................................................................	148
	Transmitter.......................................................................	149
	Receiver ..........................................................................	149
	Modem ............................................................................	150
	Data Payload Security ..........................................................	150
	Interface Specifications ......................................................................	151
	Ethernet Interface .....................................................................	151
	RS-232 Asynchronous Interface.......................................................	152
	Protection Switch Specifications............................................................	152
	Power Specifications..........................................................................	153
	Power Supply............................................................................	153
	Power Consumption ....................................................................	153
	Power Dissipation ......................................................................	154
	General Specifications........................................................................	155
	Environmental ..........................................................................	155
	Mechanical ..............................................................................	155
	ETSI compliance ........................................................................	155
13. Product End Of Life ...................................................................		156
	End-of-Life Recycling Programme (WEEE) .................................................	156
	The WEEE Symbol Explained ..........................................................	156
	WEEE Must Be Collected Separately .................................................	156
	YOUR ROLE in the Recovery of WEEE................................................	156
	EEE Waste Impacts the Environment and Health ..................................	156
14.	Abbreviations ...........................................................................	157
15.	Index......................................................................................	158

Aprisa SR User Manual

Getting Started | 11

1.Getting Started

This section is an overview of the steps required to commission an Aprisa SR radio network in the field:

Phase 1:	Pre-installation
1.	Confirm path planning.	Page	44
2.	Ensure that the site preparation is complete:	Page	47
	Power requirements.
	Tower requirements.
	Environmental considerations, for example, temperature control.
	Mounting space.
Phase 2:	Installing the radios
1.	Mount the radio.	Page	50
2.	Connect earthing to the radio.	Page	49
3.	Confirm that the:
	Antenna is mounted and visually aligned.
	Feeder cable is connected to the antenna.
	Feeder connections are tightened to recommended level.
	Tower earthing is complete.
4.	Install lightning protection.	Page	49
5.	Connect the coaxial jumper cable between the lightning protection and the	Page	53
	radio antenna port.
6.	Connect the power to the radio.	Page	54

Aprisa SR User Manual

12 | Getting Started

Phase 3:	Establishing the link
1.	If radio's IP address is not the default IP address (169.254.50.10 with a subnet	Page	131
	mask of 255.255.0.0) and you don't know the radio's IP address, see ‘Command
	Line Interface’ on page 131.
2.	Connect the Ethernet cable between the radio's Ethernet port and the PC.
3.	Confirm that the PC IP settings are correct for the Ethernet connection:	Page	59
	IP address
	Subnet mask
	Gateway IP address
4.	Open a web browser and login to the radio.	Page	63
5.	Set or confirm the RF characteristics:	Page	79
	TX and RX frequencies
	TX output power
6.	Compare the actual RSSI to the expected RSSI value (from your path planning).
7.	Fine-align the antennas.	Page	138
8.	Confirm that the radio is operating correctly; the OK, DATA, CPU and RF LEDs
	are light green (the AUX LED will be off).

Aprisa SR User Manual

Introduction | 13

2.Introduction

About This Manual

What It Covers

This user manual describes how to install and configure an Aprisa SR point-to-multipoint digital radio network.

It specifically documents an Aprisa SR radio running system software version 1.3.4.

It is recommended that you read the relevant sections of this manual before installing or operating the radios.

Who Should Read It

This manual has been written for professional field technicians and engineers who have an appropriate level of education and experience.

Contact Us

If you experience any difficulty installing or using Aprisa SR after reading this manual, please contact Customer Support or your local 4RF representative.

Our area representative contact details are available from our website:

4RF Communications Ltd

26 Glover Street, Ngauranga

PO Box 13-506

Wellington 6032

New Zealand

E-mail	[e-mail]
Web site	www.4rf.com
Telephone	[phone]
Facsimile	[phone]
Attention	Customer Services

What's in the Box

Inside the box you will find:

One Aprisa SR radio fitted with a power connector.

One Aprisa SR Accessory kit containing the following:

Aprisa SR CD

Aprisa SR Quick Start Guide

Management Cable

Aprisa SR User Manual

14 | Introduction

Aprisa SR Accessory Kit

The accessory kit contains the following items:

Aprisa SR Quick Start Guide

Aprisa SR CD

Management Cable

USB Cable USB A to USB micro B, 1m

Aprisa SR CD Contents

The Aprisa SR CD contains the following:

Software

The latest version of the radio software (see ‘Radio Software Upgrade’ on page 140).

USB Serial Driver.

Web browsers - Mozilla Firefox and Internet Explorer are included for your convenience.

Adobe™ Acrobat® Reader® which you need to view the PDF files on the Aprisa SR CD.

Documentation

User manual - an electronic (PDF) version for you to view online or print.

Product collateral - application overviews, product description, quick start guide, case studies, software release notes and white papers.

Aprisa SR User Manual

About the Radio | 15

3.About the Radio

The 4RF Aprisa SR Radio

The 4RF Aprisa SR is a point-to-multipoint digital radio providing secure narrowband wireless data connectivity for SCADA, infrastructure and telemetry applications.

The radios carry a combination of serial packet data and Ethernet data between the Base Station, Repeater Stations and Remote Stations.

The Aprisa SR is configurable as a point-to-multipoint Base Station, a Remote Station or a Repeater Station.

Aprisa SR User Manual

16 | About the Radio

Product Overview

Network Coverage and Capacity

In a simple point-to-multipoint network, an Aprisa SR, configured as a Base Station, will communicate with multiple remote units in a given coverage area. With a link range of up to 60 km a typical deployment will have 30 – 50 Remote Stations attached to the Base Station. However, geographic features, such as hills, mountains, trees and foliage, or other path obstructions, such as buildings, tend to limit radio coverage. Additionally, geography may reduce network capacity at the edge of the network where errors may occur and require retransmission. However, the Aprisa SR uses Forward Error Correction (FEC) which greatly improves the sensitivity performance of the radio resulting in less retries and minimal reduction in capacity.

Ultimately, the overall performance of any specific network will be defined by a range of factors including the geographic location, the number of Remote Stations in the Base Station coverage area and the traffic profile across the network. Effective network design will distribute the total number of Remote Stations across the available Base Stations to ensure optimal geographic coverage and network capacity.

Remote Messaging

Base Stations are fitted with omni-directional antennas and the Remote Stations use directional Yagi antennas for higher gain. On start-up the Base Station transmits a registration message which is recognized by the Remote Stations which respond with their own registration message. This allows the Base Station to record the details of all the Remote Stations active in the network.

There are two message types in the Aprisa SR network, broadcast messages and unicast messages. Broadcast messages are transmitted by the Base Station to the Remote Stations and unicast messages are transmitted by the Remote Station to the Base Station.

All the Remote Stations, within the coverage area, will receive the messages broadcast from the Base Station, but only the radio the message is intended for will action the message. Only the Base Station can receive the unicast messages transmitted from the Remote Station. Unicast messages are ignored by other Remote Stations which may be able to receive them. The Aprisa SR network is not designed for Remote Stations to communicate with other Remote Stations.

Aprisa SR User Manual

About the Radio | 17

Repeater Messaging

The Aprisa SR uses a routed protocol throughout the network whereby messages contain source and destination addresses. Upon registration, the radios populate an internal neighbor table to identify the radios in the network. The Remote Stations will register with a Base Station, or a repeater, and the repeater registers with a Base Station. In networks with a repeater, the repeater must register with the Base Station before the remotes can register with the repeater.

Additionally, all messages contain a ‘message type’ field in the header and messages are designated as either a ‘broadcast’ message, originating from a Base Station, or a ‘unicast’ message, originating from a

Remote Station.

In a network with a repeater, or multiple repeaters, the Base Station broadcasts a message which contains a message type, a source address and a destination address. The repeater receives the message and recognizes it is a broadcast message, from the message type and source address and re-broadcasts the message across the network. All Remote Stations in the coverage area will receive the message but only the radio with the destination address will act upon the message.

Similarly, the Remote Station will send a unicast message which contains a message type (unicast) a source address and a destination address (the Base Station). The repeater will receive this message; recognize the message type and source address and forward it to the destination address.

It is this methodology which prevents repeater-repeater loops. If there is repeater (A) which, in some circumstances, is able to pick up the RF signal from another repeater (B), it will not forward the message as it will only forward broadcast messages from the Base Station (recognized by the source address). For unicast messages the repeater (A) will recognize that the message (from repeater (B)) is not from a remote with which it has an association and similarly ignore the message.

Aprisa SR User Manual

18 | About the Radio

Product Features

Functions

Point-to-Point (PTP) or Point-to-Multipoint (PMP) operation half duplex. Licensed frequency bands:

VHF 136-174 MHz

UHF 400-470 MHz

Channel sizes:

12.5 kHz

25 kHz

Typical deployment of 30 Remote Stations from one Base Station with a practical limit of a few hundred Remote Stations.

Dual antenna port option for external duplexers or filters (half duplex operation) Ethernet data interface plus RS-232 asynchronous data interface.

Data encryption and authentication.

Radio and user interface redundancy (provided with Aprisa SR Protected Station).

Complies with international standards, including ETSI RF, EMC, safety and environmental standards.

Performance

Long distance operation.

High transmit power.

Low noise receiver.

Forward Error Correction.

Electronic tuning over the frequency band.

Thermal management for high power over a wide temperature range.

Usability

Configuration / diagnostics via front panel Management Port USB interface, Ethernet interface. Remote station configuration / diagnostics over the radio link.

LED display for on-site diagnostics.

Firmware upgrade and diagnostic reporting via the Host Port USB flash drive.

Simple installation with integrated mounting holes for wall, DIN rail and rack shelf mounting.

Aprisa SR User Manual

About the Radio | 19

Architecture

Product Operation

There are three components to the wireless interface: the Physical Layer (PHY), the Data Link Layer (DLL) and the Network Layer. These three layers are required to transport data across the wireless channel in the Point-to-Multipoint (PMP) configuration. The Aprisa SR DLL is largely based on the 802.15.4 MAC layer using a proprietary implementation.

Physical Layer

The Aprisa SR PHY uses a one or two frequency ½ duplex transmission mode which eliminates the need for a duplexer. However, a Dual Antenna port option is available for separate transmit and receive antenna connection to support external duplexers or filters (half duplex operation).

Remote nodes are predominantly in receive mode with only sporadic bursts of transmit data. This reduces power consumption.

The Aprisa SR is a packet based radio. Data is sent over the wireless channel in discrete packets / frames, separated in time. The PHY demodulates data within these packets with coherent detection.

The Aprisa SR PHY provides carrier, symbol and frame synchronisation predominantly through the use of preambles. This preamble prefixes all packets sent over the wireless channel which enables fast synchronisation.

Data Link Layer / MAC layer

The Aprisa SR PHY enables multiple users to be able to share a single wireless channel; however a DLL is required to manage data transport. The two key components to the DLL are channel access and hop by hop transmission.

Channel access

The Aprisa SR radio has two modes of channel access, Access Request and Listen Before Send.

Access Mode	Function
Access Request	Channel access scheme where the base stations controls the
	communication on the channel. Remotes ask for access to the
	channel, and the base station grants access if the channel is not
	occupied.
Listen Before Send	Channel access scheme which consists of base station controlled
	scheduling with remote station access using an access request /
	access grant (AR/AG) scheme.

Aprisa SR User Manual

20 | About the Radio

Access Request

This scheme is particularly suited to digital SCADA systems where all data flows through the base station. In this case it is important that the base station has contention-free access as it is involved in every transaction. The channel access scheme assigns the base station as the channel access arbitrator and therefore inherently it has contention-free access to the channel. This means that there is no possibility of contention on data originating from the base station. As all data flows to or from the base station, this significantly improves the robustness of the system.

All data messages are controlled via the AG (access grant) control message and therefore there is no possibility of contention on the actual end user data. If a remote station accesses the channel, the only contention risk is on the AR (access request) control message. These control messages are designed to be as short as possible and therefore the risk of collision of these control messages is significantly reduced. Should collisions occur these are resolved using a random back off and retry mechanism.

As the base station controls all data transactions multiple applications can be effectively handled, including a mixture of polling and report by exception.

Listen Before Send

The Listen Before Send channel access scheme is realized using Carrier Sense Multiple Access (CSMA). In this mode, a pending transmission requires the channel to be clear. This is determined by monitoring the channel for other signals for a set time prior to transmission. This results in reduced collisions and improved channel capacity.

There are still possibilities for collisions with this technique e.g. if two radios simultaneously determine the channel is clear and transmit at the same time. In this case an acknowledged transaction may be used. The transmitter requests an ACK to ensure that the transmission has been successful. If the transmitter does not receive an ACK, then random backoffs are used to reschedule the next transmission.

There are a number of parameters that can be altered for the channel access such as back off times, number of retries etc. To enable the most efficient use of the channel these parameters will differ for each network (largely dependent on number of radios in the network).

Hop by Hop Transmission

Hop by Hop Transmission is realized in the Aprisa SR by adding a MAC address header to the packet. For 802.15.4, there are 2 addresses, the source and destination addresses.

Aprisa SR User Manual

About the Radio | 21

Network Layer

Packet Routing

Packet routing is realized in the Aprisa SR by adding a network address header to the packet. This contains source and destination addresses. For the Network Layer, there are 2 addresses, the address of the originating radio and the address of the terminating radio (i.e. end to end network). This is required for routing packets across multiple hops e.g. PMP with repeaters.

The Aprisa SR uses an automated method for performing address assignment and routing information.

There are two types of packets: unicast and broadcast. Only the Base Station sends broadcasts which are received by all Remote Stations. User packets are not interpreted as the radio link is transparent.

Traffic

Data originating on the Base Station is broadcast to all Repeater Stations and Remote Stations.

Data originating on a Remote Station is unicast to the Base Station only. This can be via multiple Repeater Stations.

Data originating on a Repeater Station is unicast to the Base Station only.

Data originating on a serial port is terminated on a serial port and data originating on an Ethernet port is terminated on an Ethernet port only.

User Traffic

User traffic is prioritized depending on the Serial and Ethernet Data Priority options (see ‘Serial > Advanced’ on page 91 and ‘Ethernet > Advanced’ on page 98).

If the Serial and Ethernet Data Priority options are equal, then first come first served is invoked.

Repeater stations repeat traffic also on a first come first served basis.

Management Traffic

Ethernet Management Traffic has the same priority as Ethernet User Traffic but if the radio is not licensed for Ethernet, the Ethernet Data Priority is set to Low.

Aprisa SR User Manual

22 | About the Radio

Security

The Aprisa SR provides security features to implement the key recommendations for industrial control systems. The security provided builds upon the best in class from multiple standards bodies, including:

IEC/TR 62443 (TC65) ‘Industrial Communications Networks – Network and System Security’.

IEC/TS 62351 (TC57) ‘Power System Control and Associated Communications – Data and Communication Security’.

The security features implemented are:

Licensed radio spectrum protects against interference.

Proprietary physical layer protocol and modified MAC layer protocol based on standardized IEEE 802.15.4.

Data payload security:

CCM	Counter with CBC-MAC integrity (NIST special publication 800-38C).

Data encryption:

Counter Mode Encryption (CTR) using Advanced Encryption Standard (AES).

Data authentication:

Cipher Block Chaining Message Authentication Code (CBC-MAC) using Advanced Encryption Standard (AES).

Secured management interface protects configuration. Address filtering enables traffic source authorization.

Aprisa SR User Manual

About the Radio | 23

Interfaces

Antenna Interface

Single Antenna Option

1 x TNC, 50 ohm, female connector

Dual Antenna Port Option

2 x TNC, 50 ohm, female connectors

Ethernet Interface

2 x ports 10/100 base-T Ethernet layer 2 switch using RJ-45. Used for Ethernet user traffic and product management.

USB Interfaces

1 x Management Port using USB micro type B connector.

Used for product configuration with the Command Line Interface (CLI).

1 x Host Port using USB standard type A connector. Used for software upgrade and diagnostic reporting.

RS-232 Interface

1x RS-232 asynchronous port using RJ-45 connector. Used for RS-232 async user traffic only.

Aprisa SR User Manual

24 | About the Radio

Front Panel Connections

All connections to the radio are made on the front panel.

The functions of the connectors are (from left to right):

Designator	Description
A1 / A2	The A1, A2 are alarm connections are used in the Protected
	Station.
10 - 30 VDC; 3A	+10 to +30 VDC (negative ground) DC power input using
	Phoenix Contact 4 pin male screw fitting connector.
	AC/DC and DC/DC power supplies are available as accessories
	(see ‘External Power Supplies’ on page 54).
ETHERNET 1	Integrated 10Base-T/100Base-TX layer-2 Ethernet switch using
	RJ-45 connector.
	Used for Ethernet user traffic and product management (see
	‘Ethernet > Port Setup’ on page 93).
ETHERNET 2	Integrated 10Base-T/100Base-TX layer-2 Ethernet switch using
	RJ-45 connector.
	Used for Ethernet user traffic and product management (see
	‘Ethernet > Port Setup’ on page 93).
MGMT	Management Port using USB micro type B connector.
	Used for product configuration with the Command Line
	Interface.
	(see ‘Connecting to the Management Port’ on page 131).
	Host Port using USB standard type A connector.
	Used for software upgrade and diagnostic reporting.
	(see ‘Radio Software Upgrade’ on page 140 and ‘Maintenance >
	General’ on page 111).
SERIAL	RS-232 traffic interface using a RJ-45 connector.
	Used for RS-232 async user traffic only (see ‘Serial’ on page
	88).
ANT	TNC, 50 ohm, female connector for connection of antenna
(Antenna connector)	feeder cable (see ‘Coaxial Feeder Cables’ on page 47).

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About the Radio | 25

LED Display Panel

The Aprisa SR has an LED Display panel which provides on-site alarms / diagnostics without the need for PC.

Normal Operation

In normal radio operation, the LEDs indicate the following conditions:

	OK	DATA	CPU	RF	AUX
Solid	Alarm present			RF path fail
Red	with severity
	Critical, Major
	and Minor
Flashing				Radio not
Red				connected to a
				Base Station
Solid	Alarm present		Standby radio
Orange	with Warning		in Protected
	Severity		Station
Flashing		Tx Data or Rx	Device detect	RF path TX is	Diagnostics
Orange		Data on the	on the USB	active	Function
		USB	host port		Active
		management
		or data port
Flashing		Tx Data or Rx		RF path RX is
Green		Data on the		active
		serial port
Solid	Power on and	All interface	Processor Block	RF path is OK
Green	functions OK	ports are OK	is OK and
	and no alarms		Active radio in
			Protected
			Station

LED Colour	Severity
Green	No alarm – information only
Orange	Warning alarm
Red	Critical, major or minor alarm

Software Upgrade

During a software upgrade, the LEDs indicate the following conditions:

Software upgrade started - the OK LED flashes orange.

Software upgrade progress indicated by running AUX to DATA LEDs.

Software upgrade completed successfully - the OK LED solid orange.

Software upgrade failed - any LED flashing red during the upgrade.

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26 | About the Radio

Test Mode

Remote Station and Repeater Station radios have a Test Mode which presents a real time visual display of the RSSI on the LED Display panel. This can be used to adjust the antenna for optimum signal strength (see ‘Maintenance > Test Mode’ on page 115 for Test Mode options).

To enter Test Mode, press and hold the ENTER button on the radio LED panel until all the LEDs flash green (about 3 - 5 seconds).

Note: The response time is variable and can be up to 5 seconds.

To exit Test Mode, press and hold the ENTER button until all the LEDs flash red (about 3 – 5 seconds).

The RF LED will be green if the network is operating correctly.

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Product Options | 27

4.Product Options

Dual Antenna Port

The standard Aprisa SR uses a one or two frequency ½ duplex transmission mode which eliminates the need for a duplexer. However, a dual antenna port option is available for separate transmit and receive antenna connection to support external duplexers or filters. The transmission remains half duplex.

Option Example	Part Number
Single Antenna Port	APSR-N400-012-SO-12-ETAA
Dual Antenna Port	APSR-N400-012-DO-12-ETAA

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28 | Product Options

Protected Station

The Aprisa SR Protected Station provides radio and user interface protection for Aprisa SR radios when configured as a Base Station. The RF ports and interface ports from two standard Aprisa SR Radios are switched to the standby radio if there is a failure in the active radio.

Option Example	Part Number
Aprisa SR Radio	APSR-N400-012-SO-12-ETAA
Aprisa SR Protected Station	APSR-R400-012-SO-12-ETAA

The Aprisa SR Protected Station is comprised of an Aprisa SR Protection Switch and two standard Aprisa SR radios. The Aprisa SR radios can be any of the currently available Aprisa SR radio frequency bands, channel sizes or single / dual antenna port options.

By default, the Aprisa SR Protected Station is configured with the left hand radio (A) designated as the primary radio and the right hand radio (B) designated as the secondary radio.

Each radio is configured with its own unique IP and MAC address and the address of the partner radio.

On power-up, the primary radio will assume the active role and the secondary radio will assume the standby role. If, for some reason, only one radio is powered on it will automatically assume the active role.

Operation

In normal operation, the active radio carries all RS-232 serial and Ethernet traffic over the radio link and the standby radio is unused with its transmitter turned off. Both radios are continually monitored for correct operation and alarms are raised if an event occurs.

The active radio sends regular ‘keep alive’ messages to the standby radio to indicate it is operating correctly. In the event of a failure on the active radio, the RF link and user interface traffic is automatically switched to the standby radio.

The failed radio can then be replaced in the field without interrupting user traffic (see ‘Replacing a Protected Station Faulty Radio’ on page 33).

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Product Options | 29

Configuration Management

The active and standby radios are separately managed by SuperVisor via the Local and Partner IP addresses. Changes to the configuration in one radio must be reflected in the partner radio.

Changes to the Network Table are automatically synchronized from the active radio to the standby radio but the Network Table is only visible on the active radio. This synchronization does not occur if the Hardware Manual Lock is active.

Switch Over

The switch over to the standby radio can be initiated automatically, on fault detection, or manually via the Hardware Manual Lock switch on the Protection Switch or the Software Manual Lock from SuperVisor. Additionally, it is possible to switch over the radios remotely without visiting the station site, via the remote control connector on the front of the Protection Switch.

On detection of an alarm fault the switch over time is less than 0.5 seconds. Some alarms may take up to 5 seconds to be detected.

The Protection Switch has a switch guard mechanism to prevent protection switch oscillation. This guard time will block another switch over with 20 seconds of the previous switch over. At the end of the guard time period, the switching criteria will be evaluated and any protection switch will occur immediately if necessary.

Switching Criteria

The Protected Station will switch over operation from the active to the standby radio if any of the configurable alarm events occur or if there is a loss of the ‘keep alive’ signal from the active radio.

It is possible to configure the alarm events which will trigger the switch over. It is also possible to prevent an alarm event triggering a switch over through the configuration of blocking criteria.

Any of the following alarm events can be set to trigger or prevent switching from the active radio to the standby radio (see ‘Events > Events Setup’ on page 126).

PA current	Tx AGC
Tx reverse power	Temperature threshold
Thermal shutdown	RSSI threshold
Rx CRC errors	RF no receive data
Ethernet port 1 – no receive data	Ethernet port 1 – data receive errors
Ethernet port 1 - data transmit errors	Ethernet port 2 – no receive data
Ethernet port 2 – data receive errors	Ethernet port 2 - data transmit errors
Serial port – no receive data	Serial port – data receive errors
Component failure	Calibration failure
Configuration not supported

Switch over will not occur if there is a power failure or an active alarm event is detected on the standby radio which has been configured as a ‘blocking criteria’. Switch over will be initiated once either of these conditions is rectified, i.e. power is restored or the alarm is cleared.

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30 | Product Options

Hardware Manual Lock

The Hardware Manual Lock switch on the Protection Switch provides a manual override of the active / standby radio.

When this lock is activated, the selected radio (A or B) becomes the active radio regardless of the Software Manual Lock and the current switching or block criteria.

When the lock is deactivated (set to the Auto position), the protection will become automatic and switching will be governed by normal switching and blocking criteria.

The state of the lock is indicated by the three LEDs on the Protection Switch:

A LED Orange	Manual Lock asserted and radio A is active
B LED Orange	Manual Lock asserted and radio B is active
Auto LED Green	Manual Lock is in Auto position

Only one of three LEDs will be active at a time.

The Protection Switch also has a Software Manual Lock (see ‘Lock Active’ on page 119). The Hardware Manual Lock takes precedence over Software Manual Lock if both diagnostic functions are activated i.e. if the Software Manual Lock is set to ‘Primary’ and the Hardware Manual Lock set to ‘Secondary’, the system will set the Secondary radio to Active.

When a Hardware Manual Lock is deactivated (set to the Auto position), the Software Manual Lock is reevaluated and locks set appropriately.

Remote Control

The switch over to the standby radio can be initiated via the Remote Control connector on the front of the Protection Switch. This control will only operate if the Hardware Manual Lock switch is set to the Auto position.

The inputs are logic inputs with 220 Ω pullup to +5 VDC. They require a pull down to ground to activate the control. The ground potential is available on the connector (see ‘Protection Switch Remote Control Connections’ on page 143).

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Product Options | 31

Installation

Mounting

The Aprisa SR Protected Station is designed to mount in a standard 19 inch rack.

Cabling

The Aprisa SR Protected Station is delivered pre-cabled with power, interface, management and RF cables.

The set of interconnect cables is available as a spare part (see ‘Spares’ on page 34).

Power

A +10.5 to +30 V DC external power source must be connected to both the A and B Phoenix Contact 2 pin male power connectors. The maximum combined power consumption is 35 Watts.

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32 | Product Options

Maintenance

Changing the Protected Station IP Addresses

To change the IP address of a Protected Station radio:

1.Using the Hardware Manual Lock switch, force the primary radio to active.

2.Change the IP address of either or both radios.

3.Change the Partner IP address of either or both radios.

4.Set the Hardware Manual Lock switch to the Auto position.

Protected Station Software Upgrade

The Protected Station software upgrade can be achieved without disruption to traffic. Assuming the Primary radio is active and the Secondary radio is standby

1.Using the Hardware Manual Lock switch, force the primary radio to active.

2.Carefully remove the Host Port USB cable connecting the secondary radio to the Protection Switch and insert the USB flash drive with the new software release into the secondary radio Host Port .

3.Power cycle the secondary radio. The radio will be upgraded with the new software.

4.When the secondary radio upgrade is completed, remove the USB flash drive, restore the Host Port USB cable to Protection Switch, power cycle the secondary radio and wait for it to become standby.

5.Using the Hardware Manual Lock switch, force the secondary radio to active.

6.Carefully remove the Host Port USB cable connecting the primary radio to the Protection Switch and insert the USB flash drive with the new software release into the primary radio Host Port .

7.Power cycle the primary radio. The radio will be upgraded with the new software.

8.When the primary radio upgrade is completed, remove the USB flash drive, restore the Host Port USB cable to Protection Switch, power cycle the primary radio and wait for it to become standby.

9.Set the Hardware Manual Lock switch to the Auto position. The secondary radio will remain active and the primary radio will remain standby. To set the primary radio to active, use the hardware lock switch to select the primary radio and wait for it to become active, then set the hardware manual lock switch to the Auto position.

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Product Options | 33

Replacing a Protected Station Faulty Radio

Replacing a faulty radio in a Protected Station can be achieved without disruption to traffic. Assuming that the primary radio is active and the secondary radio is faulty and needs replacement:

1.Ensure the replacement radio has the same version of software installed as the primary radio. If necessary, upgrade the software in the replacement radio.

2.Set the RF Interface MAC Address (see ‘Maintenance > Advanced’ on page 121). This MAC address is present on chassis label.

3.Using SuperVisor > Maintenance > Advanced ‘Save Configuration to USB’ and ‘Restore Configuration from USB’ operation, clone the primary radio’s configuration to the replacement radio.

4.Configure the replacement radio as the secondary radio and setup the other protection parameters (see ‘Terminal > Operating Mode’ on page 76).

5.Using the Hardware Manual Lock switch, force the primary radio to active.

6.Carefully remove the faulty radio from the protection switch and install the replacement radio.

7.Power on the replacement radio and wait for it to become standby.

8.Set the Hardware Manual Lock switch to the Auto position.

Setting the Software Manual Lock

To make changes remotely to the Protected Station radios, the Software Manual Lock must be set to prevent switch-over while making the changes (see ‘Lock Active’ on page 119). This procedure should be followed when making changes that may interrupt traffic or cause a trigger a switch condition.

This procedure assumes that the Hardware Manual Lock is set to the Auto position, and there are no active switching alarm conditions:

1.Login to the primary radio (left hand radio A by default).

2.Set the Software Manual Lock (Lock Active To) to Primary. The primary radio will become active i.e. traffic will be switched to the primary radio.

3.Login to the secondary radio (right hand radio B by default).

4.Set the Software Manual Lock (Lock Active To) to Primary. This will prevent the secondary radio from becoming active.

5.Make the changes to the secondary radio if required.

6.Set the secondary radio Software Manual Lock (Lock Active To) to Automatic.

7.Login to the primary radio (left hand radio A by default).

8.Set the Software Manual Lock (Lock Active To) to Secondary. This will prevent the primary radio from becoming active.

Note: The Primary radio will become ‘Standby’ and the Secondary radio will become ‘Active’.

9.Make the changes to the primary radio if required.

10.Set the primary radio Software Manual Lock (Lock Active To) to Automatic.

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34 | Product Options

Spares

The Aprisa SR Protection Switch is available as a spare part. This spare includes the protection switch and 2 sets of Protection Switch interconnect cables (one set is 7 cables).

Part Number	Part Description
APSP-SPSW	4RF Spare, Aprisa SR, Protection Switch

The set of interconnect cables is available as a spare part (set of 7 cables).

Part Number	Part Description
APSP-SPSC-XS7	4RF Spare, Aprisa SR, Protection Switch Cables, Set Of 7

Replacing a Faulty Protection Switch

Note: Replacing a faulty Protection Switch will disrupt traffic.

Move the radios, the interconnect cables, the interface cables and the power cables to the replacement Protection Switch.

On both Protected Station radios:

1.Power on the radio and wait for it to become ready.

2.Using SuperVisor > Maintenance > Advanced, enter the RF Interface MAC address shown on the

Protection Switch label (see ‘RF Interface MAC address’ on page 122).

3.Using SuperVisor > Maintenance > Advanced, Decommission the node (see ‘Decommission Node’ on page 122) and then Discover the Nodes (see ‘Discover Nodes’ on page 122).

Ensure that the Hardware Manual Lock switch is set to the Auto position.

The Aprisa SR Protected Station is now ready to operate.

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Product Options | 35

Data Driven Protected Station

The Aprisa SR Data Driven Protected Station provides radio and RS-232 serial port user interface protection for Aprisa SR radios when configured as a Base Station.

Option Example	Part Number
Aprisa SR Radio (Dual Antenna Port option)	APSR-N400-012-DO-12-ETAA
Aprisa SR Data Driven Protected Station	APSR-D400-012-DO-12-ETAA

The Aprisa SR Data Driven Protected Station shown is comprised of two standard Aprisa SR dual antenna port option radios and two external duplexers mounted on 19" rack mounting shelves.

The Aprisa SR radios can be any of the currently available Aprisa SR radio frequency bands, channel sizes or single / dual antenna port options.

By default, the Aprisa SR Data Driven Protected Station is configured with the left hand radio (A) designated as the primary radio and the right hand radio (B) designated as the secondary radio.

Each radio is configured with its own unique IP and MAC address and the address of the partner radio.

On power-up, the primary radio will assume the active role and the secondary radio will assume the standby role. If, for some reason, only one radio is powered on it will automatically assume the active role.

Operation

The active radio is determined explicitly by which radio receives data on its RS-232 serial port input from the interface.

The active radio carries all RS-232 serial traffic over its radio link and the standby radio is unused with its transmitter turned off.

If data is received on the RS-232 serial port interface input of the standby radio, it will immediately become the active radio and the radio which was active will become the standby radio.

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36 | Product Options

Switch Over

The active radio is determined explicitly by which radio receives data on its RS-232 serial port.

The switching and blocking criteria used for the standard Protected Station do not apply. This means that events and alarms on the unit are not used as switching criteria.

Configuration Management

The active and standby radios are separately managed by SuperVisor via the Local and Partner IP addresses. Changes to the configuration in one radio must be reflected in the partner radio.

Changes to the Network Table are automatically synchronized from the active radio to the standby radio but the Network Table is only visible on the active radio.

Aprisa SR User Manual

Product Options | 37

Installation

Mounting

The Aprisa SR Data Driven Protected Station is designed to mount in a standard 19” rack on two 1U rack mounting shelves.

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38 | Product Options

Cabling

The Aprisa SR Data Driven Protected Station is delivered with the radios, duplexers, rack mounting shelves and RF cables.

Note: The picture demonstrates the RF cabling but the product is delivered with the cables separately packaged.

The set of interconnect cables is available as a spare part.

Power

A +10.5 to +30 V DC external power source must be connected to both the A and B Phoenix Contact 4 pin male power connectors. The maximum combined power consumption is 35 Watts.

Aprisa SR User Manual

Implementing the Network | 39

5.Implementing the Network

Network Topologies

The following are examples of typical Network Topologies:

Point-To-Point Network

Point-to-Multipoint Network

Point-to-Multipoint with Repeater 1

Point-to-Multipoint with Repeater 2

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40 | Implementing the Network

Initial Network Deployment

Install the Base Station

To install the Base Station in your FAN (Field Area Network):

1.Install the Base Station radio (see ‘Installing the Radio’ on page 50).

2.Set the radio Network ID (FAN) to a unique ID in your entire network (see ‘Terminal > Device’ on page 74).

3.Set the radio IP address (see ‘Terminal > Device’ on page 74).

4.Set the radio frequencies to the frequencies you wish to operate from (see ‘Radio > Basic’ on page 79).

5.Set the radio operating mode to ‘Base Station’ (see ‘Terminal > Operating Mode’ on page 76).

6.Set the radio security settings (see ‘Security > Settings’ on page 104).

Installing the Remote Stations

To install the Remote Stations in your FAN:

1.Install the Remote Station radio (see ‘Installing the Radio’ on page 50).

2.Set the radio Network ID (FAN) to the same ID as the other stations in the FAN (see ‘Terminal > Device’ on page 74).

3.Set the radio IP address (see ‘Terminal > Device’ on page 74).

4.Set the radio frequencies to the Base Station / Repeater Station frequencies you wish to operate from (see ‘Radio > Basic’ on page 79).

5.Set the radio operating mode to ‘Remote Station’ (see ‘Terminal > Operating Mode’ on page 76).

6.Set the radio security settings to the same as the Base Station (see ‘Security > Settings’ on page 104). The Base Station will automatically allocate a node address to the new Remote Station.

Install a Repeater Station

To install a Repeater Station in your FAN:

1.Install the Repeater Station radio (see ‘Installing the Radio’ on page 50).

2.Set the radio Network ID (FAN) to the same ID as the other stations in the FAN (see ‘Terminal > Device’ on page 74).

3.Set the radio IP address (see ‘Terminal > Device’ on page 74).

4.Set the radio frequencies to Base Station frequencies you wish to operate from (see see ‘Radio > Basic’ on page 79).

5.Set the radio operating mode to ‘Repeater Station’ (see ‘Terminal > Operating Mode’ on page 76).

6.Set the radio security settings to the same as the Base Station (see ‘Security > Settings’ on page 104).

7.Increase the radio network radius by one on all stations in the FAN (see ‘Terminal > Device’ on page 74).

The Base Station will automatically allocate a node address to the new Repeater Station.

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Implementing the Network | 41

Network Changes

Adding a Repeater Station

To add a Repeater Station to your FAN:

1.Install the Repeater Station radio (see ‘Installing the Radio’ on page 50).

2.Set the radio Network ID (FAN) to the same ID as the other stations in the FAN (see ‘Terminal > Device’ on page 74).

3.Set the radio IP address (see ‘Terminal > Device’ on page 74).

4.Set the radio frequencies to the Base Station frequencies you wish to operate from (see ‘Radio > Basic’ on page 79).

5.Set the radio operating mode to ‘Repeater Station’ (see ‘Terminal > Operating Mode’ on page 76).

6.Increase the radio network radius by one on all stations in the FAN (see ‘Terminal > Device’ on page 74).

The Base Station will automatically allocate a node address to the new Repeater Station.

To remove a Repeater Station from your FAN:

1.Turn the power off on the Remote Station radios operating from the Repeater Station radio you wish to remove.

2.Turn the power off on the Repeater Station radio you wish to remove.

3.Decrease the network radius by one on all stations in the FAN (see ‘Terminal > Device’ on page 74).

Adding a Remote Station

To add a Remote Station to your FAN:

1.Install the Remote Station radio (see ‘Installing the Radio’ on page 50).

2.Set the radio Network ID (FAN) to the same ID as the other stations in the FAN (see ‘Terminal > Device’ on page 74).

3.Set the radio IP address (see ‘Terminal > Device’ on page 74).

4.Set the radio frequencies to the Base Station / Repeater Station frequencies you wish to operate from (see ‘Radio > Basic’ on page 79).

5.Set the radio operating mode to ‘Remote Station’ (see ‘Terminal > Operating Mode’ on page 76).

The Base Station will automatically allocate a node address to the new Remote Station.

To remove a Remote Station from your FAN:

1.Turn the power off on the Remote Station radio you wish to remove. This is the only action that is required.

Aprisa SR User Manual

Preparation | 43

6.Preparation

Bench Setup

Before installing the links in the field, it is recommended that you bench-test the links. A suggested setup for basic bench testing is shown below:

When setting up the equipment for bench testing, note the following:

Earthing - each radio should be earthed at all times. The radio earth point should be connected to a protection earth.

Attenuators - In a bench setup, there should be 60 - 80 dB at up to 1 GHz of 50 ohm coaxial attenuation, capable of handling the transmit power of +37 dBm (5 W) between the radios’ antenna connectors.

Splitter – If more than two radios are required in your bench setup, a multi-way splitter is required. The diagram shows a two way splitter.

This splitter should be 50 ohm coaxial up to 1 GHz and capable of handling the transmit power of +37 dBm (5 W).

Cables - use double-screened coaxial cable that is suitable for use up to 1 GHz at ≈ 1 metre.

CAUTION: Do not apply signals greater than +10 dBm to the antenna connection as they can damage the receiver.

Aprisa SR User Manual

44 | Preparation

Path Planning

The following factors should be considered to achieve optimum path planning:

Antenna Selection and Siting.

Coaxial Cable Selection.

Linking System Plan.

Antenna Selection and Siting

Selecting and siting antennas are important considerations in your system design.

The antenna choice for the site is determined primarily by the frequency of operation and the gain required to establish reliable links.

Base or Repeater Station

The predominant antenna for a Base Station or a Repeater Station is an omni-directional collinear gain antenna.

Omni Directional Collinear Antennas

	Factor	Explanation
	Frequency	Often used in 380-530 MHz bands
	Gain	Varies with size (5 dBi to 8 dBi typical)
	Wind loading	Minimal
	Tower aperture required	Minimal
	Size	Range from 2 m to 3 m length
	Polarization	Vertical

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Preparation | 45

Remote Station

There are two main types of directional antenna that are commonly used for Remote Stations, Yagi and corner reflector antennas.

Yagi Antennas

	Factor	Explanation
	Frequency	Often used in 350-600 MHz bands
	Gain	Varies with size (typically 11 dBi to 16
		dBi)
	Stackable gain increase	2 Yagi antennas (+ 2.8 dB)
		4 Yagi antennas (+ 5.6 dB)
	Size	Range from 0.6 m to 3 m in length
	Front to back ratio	Low (typically 18 to 20 dB)

It is possible to increase the gain of a Yagi antenna installation by placing two or more of them in a stack. The relative position of the antennas is critical.

Example of stacked antennas

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46 | Preparation

Corner Reflector Antennas

	Factor	Explanation
	Frequency	Often used in 330-960 MHz bands
	Gain	Typically 12 dBi
	Size	Range from 0.36 m to 0.75 m in length
	Front to back ratio	High (typically 30 dB)
	Beamwidth	Broad (up to 60°)

Antenna Siting

When siting antennas, consider the following points:

A site with a clear line of sight to the remote radio is recommended. Pay particular attention to trees, buildings, and other obstructions close to the antenna site.

Example of a clear line-of-sight path

Any large flat areas that reflect RF energy along the link path, for instance, water, could cause multipath fading. If the link path crosses a feature that is likely to cause RF reflections, shield the antenna from the reflected signals by positioning it on the far side of the roof of the equipment shelter or other structure.

Example of a mid-path reflection path

The antenna site should be as far as possible from other potential sources of RF interference such as electrical equipment, power lines and roads.

The antenna site should be as close as possible to the equipment shelter.

Note: Wide angle and zoom photographs taken at the proposed antenna location (looking down the proposed path), can be useful when considering the best mounting positions.

Aprisa SR User Manual