ANALOGUE vs DIGITAL RADIO SYSTEMS Networks for Telemetry Applications
Mar 30, 2015
ANALOGUE vs
DIGITAL RADIO SYSTEMS
ANALOGUE vs
DIGITAL RADIO SYSTEMS
Networks for Telemetry Applications
Where are Data Radio Systems Used?Where are Data Radio Systems Used?
• Wide area networks for machine to machine data communications.Wide area networks for machine to machine data communications.• Remote monitoring and control of industrial systems.Remote monitoring and control of industrial systems.• Remote logging and reporting to SCADA and MES systems.Remote logging and reporting to SCADA and MES systems.• Security and remote access systems. Security and remote access systems.
Telemetry System ModelTelemetry System Model
CONTROLCENTRE
CommunicationsNetwork
SCADA SYSTEM
HUMAN INTERFACE&
DATA MANAGEMENT
MONITORING&
CONTROL
BULKWATERSUPPLY
TELEMETRY NETWORK
SEWAGE&
WASTE
STATUS POINTS&
ALARMS LOGGED DATA&
ALARMS
METERINGSTATIONS
Analogue Radio Network TopologyAnalogue Radio Network Topology
RemoteStation
Radio Modem
RTU
Radio Repeater
RemoteStation
Radio Modem
RTUMaster Station
SCADA
Radio Modem
Distant Stations
Features of Analogue Radio SystemsFeatures of Analogue Radio Systems
• Analogue Radio SystemsAnalogue Radio Systems
– Can cover large distances with repeatersCan cover large distances with repeaters
– Slow over the air data rate – max 1200baudSlow over the air data rate – max 1200baud
– Requires additional interface module between radio and device – Requires additional interface module between radio and device –
Serial to FSK converterSerial to FSK converter
– Radio requires unique alignment for each device interface – Radio requires unique alignment for each device interface –
Cannot just be swapped out on service/replacementCannot just be swapped out on service/replacement
– No management available on radio networkNo management available on radio network
– High maintenance on radios – routine tuningHigh maintenance on radios – routine tuning
– Lower cost of deployment – analogue radios are cheaperLower cost of deployment – analogue radios are cheaper
Digital Radio Network TopologyDigital Radio Network Topology
RemoteStation
Radio Modem
RTU
Radio Repeater
RemoteStation
Radio Modem
RTUMaster Station
SCADA
Radio Modem
Distant Stations
Features of Digital Radio SystemsFeatures of Digital Radio Systems• Digital Radio SystemsDigital Radio Systems
– Can cover large distances with repeatersCan cover large distances with repeaters
– Fast over the air data rate – Fast over the air data rate –
Typically 9600baud but can go up to 19200baudTypically 9600baud but can go up to 19200baud
– Better sensitivity – typical -112dBm @ 9600baudBetter sensitivity – typical -112dBm @ 9600baud
– Does not require additional interface module between radio and device – Does not require additional interface module between radio and device –
Direct Serial or Ethernet interface to the radioDirect Serial or Ethernet interface to the radio
– Radio does not require alignment for device interface – Radio does not require alignment for device interface –
Plug & Play for replacement/servicePlug & Play for replacement/service
– Comprehensive management software for radio networks – Comprehensive management software for radio networks –
Diagnostics, configuration, interface to other environments (SCADA)Diagnostics, configuration, interface to other environments (SCADA)
– No maintenance on radios – no routine tuningNo maintenance on radios – no routine tuning
– Higher cost of deployment – digital radios are more expensiveHigher cost of deployment – digital radios are more expensive
0
500
1000
1500
2000
2500
3000
PreEmp DeEmp PreEmp DeEmp PreEmp DeEmp Data Total
Transmission Stage
Tim
e (m
s)
Analogue @ 1200baud
Digital @ 9600baud
Base Station Repeater #1 Repeater #2
Time of Flight ComparisonTime of Flight ComparisonAnalogue vs Digital Radio
960bits Data Packet
700
300 40
0
200 30
0
100
800
2800
2 2 22 2 2 100
112
Comparison SummaryComparison Summary
Low cost of maintenanceHigher cost of maintenance
Higher cost of deploymentLower costs of deployment
Comprehensive network management toolsNo “in band” remote management
Once off setup, no routine maintenanceRoutine alignment and tuning
Direct interface for Serial/Ethernet devicesRequires additional interface to device
Max 19200baud over the air data rateMax 1200baud over the air data rate
Supports repeater networksSupports repeater networks
Digital RadioAnalogue Radio8 x
Faster