# Presentation: 203062

## Digital Data Communications in Air Quality Monitoring

- Better, cheaper, faster?

- Erik Aaboe, New Mexico Environment Department

## Questions?

- How many are familiar with their monitoring system communications methods?
- Who knows what they cost?
- Everyone satisfied with that cost?
- Who uses Leased Lines?
- Part of a Local Area Network?
- Plain Old Telephone Services?
- Analog Cellular?
- Digital Cellular?
- Digital Subscriber Lines / Cable Internet?

## NMED Situation

- 23 continuous monitoring sites
- All on Plain Old Telephone Services (POTS) lines
- Worked fine for daily polling
- Hourly calls costly
- (for real-time web & AIRNow posting)
- Short-term solutions
- Reduce call frequency (every other hour, etc.)
- Split polling assignments to LAN locations with local calls
- Change analog cellular to local phone number

## NMED Phone Costs & Issues

- ~$42.00 / month for phone service at each site
- Long distance charges for hourly calls at 8760 hours / year.
- Each call at approximately one minute = $876 for total cost of ~$1350 / site / year
- Phone lines not at all desired locations

## Digital Cellular

- Device $350-$550 to connect each site to Internet
- Poll from polling machine over Internet
- Data Plan for service – depends upon usage
- 2 MB / month = $10 / month
- No per-call connection costs
- If desired, can download shorter interval data (5 minute & 15 minute averages, e.g.)

## Digital Modem Technologies Available

- Airlink Redwing
- “unintelligent” device acts as modem for PC-based systems
- Establishes DUN (dial-up networking) connection to Internet
- Setup with a static IP address
- Airlink Raven
- Same capabilities but has embedded Operating System for traditional datalogger systems

## Slide 7

## Raven

- _Features_
- High speed data transfer rate
- Full duplex transceiver
- Low power consumption
- iDEN - Nextel
- CDMA 1XRTT – VZW, SPCS, Alltel
- GPRS, EDGE – Cingular, Dobson
- Environmental operating range –30 to +75 C
- LEDs show status of modem operation
- Serial port for mobile data applications
- Over the air programmable firmware upgrades
- On-board ARM processor - ALEOS
- Class I Division II certified (Gas & Oil Industry)

- _Applications_
- Utilities
- Telemetry/SCADA
- Fire/EMS/Police
- Workforce Automation
- ATM/POS
- Router Back-up

## SCADA, Telemetry, and Data Acquisition

- <date/time>

- Verizon “Enhanced” Coverage Map

## Possible Digital Cellular Issues

- Can my polling system connect to an IP address?
- Does device work with my datalogging system?
- Does the remote system stay connected?
- One line batch file to reconnect for PCs with Redwings
- Stayalive ping feature for Ravens
- Will my IT department allow this technology?
- Does it save money or improve performance?
- Is the remote equipment secure?

## Security

- Securing Remote Devices
- IPSec for PC based systems (on W2000, XP PCs)
- “Friendly IP” list for Raven
- Only acknowledge approved IP addresses or subnets
- Invisible to the rest of the Internet
- Getting Through Agency Firewalls
- Port usage for polling (use 443 or 8088 or a commonly open port)
- To set rules on remote system – are agency IP addresses NATted? Go to http://whatismyip.com or http://dnsstuff.com from polling PC to determine

## Possible Benefits

- More bandwidth available than current system?
- Connect to remote system using remote access tools without interrupting polling
- Allow connections from others (support contractors, troubleshooters, site operators from home, etc.)
- Poll data from multiple locations?

## Thank You

- For information contact erik.aaboe@state.nm.us

- Questions?