Wireless Operational Link for the Field (WOLF) - Results

This is the final post of a series of posts dedicated to my response to challenges deploying wireless access to research plots at Toolik field station.

Results

Overall, the entire experiment went very well. Wireless network was delivered to roughly 60% more research plots than prior to deploying the WOLF rig; for a price of around $700. An additional setup deployed on the other side of the hill would have increased coverage to approximately 80% coverage. Major issues encountered are listed below:

Issue #1: Basic Network Control: The biggest hurdle when deploying an AP that doesn't involve interaction with the IT network administrators is ability to extend existing IP ranges. This would have been desirable for managing remote sensors via IP. As a work around, I was eventually able to find a web-based service to manage my Internet of Things (IoT) Intel Edison devices communicating over http ports. Being a former HPC systems administrator, this was a difficult adjustment for me from IP to http port control as I am used to being able to ssh to my systems. However, the meshcentral.com service gave me 95% of what I needed to manage the remote sensor boxes.

Issue #2: Battery Longevity: My tests at home with mild traffic resulted in the Goal Zero battery lasting about 12-15 hours with both AP and high-gain antenna. In the field, the battery lasted for a much shorter time, roughly 9-11 hours. Even when a second solar panel was added, the performance under moderate traffic was still only slightly better. A possible reason for shorter battery life may be due to the AP occasionally losing the Toolik wifi signal. It was also overcast for a few days in a row. Also interesting is I found the Toolik network itself occasionally drops packets even with good signal. I don't believe weather (cold specifically) was a factor as the temperatures were very warm during the deployment tests.

Issue #3: Geophysical Limitations: The hills around Toolik are solid rock. Wifi signals don't go through solid rock well if at all. This reality made the wifi range uneven. In addition, the rocky hills also made the antenna pattern very noticeable. For instance, the high gain antenna emits wifi signal in an omnidirectional pattern. I found that if I stood in a lower valley, the signal from my WOLF unit disappeared even though I was physically within range. Similarly the Toolik wifi signal extended further into the field at the lower elevation, which happened to be at a similar elevation. Again, at a higher location on the hill, the same Toolik wireless signal could not be picked up at much closer range than in lower areas.

Final Remarks

The WOLF network experiment is a first step towards delivering network connectivity to research plots in the field around Toolik Field Station. The equipment was chosen for ease of use, portability and cost over high performance. The configuration of the WOLF setup is not intended as a long-term, permanent solution for wireless extension at Toolik. Instead, this experiment presents an alternative solution that can be deployed today with little effort from Toolik operations. This component of the Arctic Glass project is an initial survey to examine existing wireless range, as well as a "quick and dirty" interim solution until long-term solutions are put in place. All of which is in support of other experiments for the Arctic Glass project; including remote sensor connectivity to cloud storage and Google Glass retrieval of data while on the WOLF extended network.

Wireless Operations Link for the Field (WOLF) - Survey and Design

This post will discuss the design I put together for a portable, solar-powered, easy-to-use wireless solution for Toolik research plots located outside of the camp's immediate wireless range.

First I'll summarize deployment procedure:

PROCEDURE: Overall, the WOLF rig went in pretty smoothly. We did a little bit of engineering hacking to find a good stand (surveyors tripod), grounding method (wire and rebar), and extra insurance against the elements (battery went partially in a plastic bag). We also did a rough wifi signal survey to find the edge of the existing Toolik wifi network to figure out the best location for the rig. The prep done with the router/AP itself was minimal. I changed the admin password, connected to the existing Toolik wifi in AP mode, and upgraded the firmware. I didn't bother with security on the wifi as the Toolik network is open.

Design

 The WOLF rig was intentionally designed to be a "bare minimum" outfit that any researcher, regardless of networking expertise, could put together. There was also significant consideration given to the portability of the rig as some researchers expressed interest in temporary wifi setups that could be brought into the field and taken down the same day. Components of the setup that were easy to purchase and intended for consumer-level experience were preferred over components that required more technological expertise to work with. Finally, reasonable cost for performance was a significant factor in component choices. **Note: 2.4GHz was chosen intentionally for 2 reasons: 1 - backwards compatibility if the Toolik wifi hadn't yet been upgraded to 5Ghz. 2 - Physically limit bandwidth consumption from the WOLF network into the Toolik network to prevent disruptions of the camp's wifi service.

** Cooler was not used given warm temperatures **

Cost Breakdown

Router/AP: $214
High Gain Antenna: $120
Battery / Generator: $230
Solar Panel: $89
Waterproof Ethernet, Antenna, Adapter Cables: $58

(does not include stand or grounding supplies)

Total Setup Cost: $711

Specifications

The following are specifications for each of the major components of the WOLF rig.

-- Router/AP --

Model: Hawking Technology HOW2R1

Network Specifications	IEEE 802.11b/g/n
Frequency	2.4000~2.4835GHz
Speed	Up to 300Mbps
Interface	Wireless 802.11 b/g/n or Ethernet 10/100M
Power	48V, 0.5A Switching Power Adapter (PoE)
Security	WPA, WPA2, WEP Full Router Security Features: Firewall, Demilitarized Zone (DMZ), URL Blocking, Network Address Translation, MAC Address Filtering, IP Address Filtering, Access Control, Denial of Service (DoS)
Receiving Radio	Antenna: 1 x 11dBi Directional Antenna Output Power: 11n:18 ±1.5dBm 11g:21±1.5dBm 11b:23±1.5dBm
Broadcasting Radio	Antenna: 2 x External 5dBi Omni-Directional Antennas Output Power: 11n: 15±1dBm 11g: 15±1dBm 11b: 18±1dBm Broadband Router Features: DHCP Server, Firewall, Demilitarized Zone (DMZ), URL Blocking, QoS (Quality of Service), Virtual Servers/Port Forwarding, Network Address Translation, MAC Address Filtering, IP Address Filtering, Access Control, Denial of Service (DoS), Remote Management
Hardware	Repeater:  Antenna Jacks: Two N-Type Connetors One 10/100M Ethernet Ports PoE Injector: Power + Data Out Port DC 48V LAN Port
Product Weight	Repeater: 481g or 1.06 lb Antenna: 68g or .15lb (each Onmi-Directional Antenna) PoE Injector: 6g or 0.1 lb
Product Dimension	Repeater:6.9(H) x 5.5 (W)x 3.5 (D) in Antenna: 8(H) x 5.25(W) , Base: 3.5(D) in PoE Injector: 3(L)x 2.7 (W)x .75(H)in
Temperature	Operating: -20~70° Storage: -40~80°C
Humidity	Operating: 10~90% (Noncondensing) Storage: 5~95% (Noncondensing)

Manufacturer Website: http://hawkingtech.com/products/hi-gain_wireless_networking/high_power_wi-fi_solutions/how2r1.html

-- High Gain Antenna --

Model: Hawking Technology HAO15SIP

Network Specifications:

•  IIEEE 802.11b/g
  

Electrical Properties

•  Frequency: 2.4~2.4835 Ghz
•  Impedence: 50 Ohms Nominal
•  Gain: 15dBi
•  Radiation: Omni
•  Polorization: Vertical
•  H-Plan:360º
•  E-Plan: 30º

Manufacturer Website:http://hawkingtech.com/products/hawking_products/outdoor_wireless_solutions/hao15sip.html

-- Solar Battery + Panel --

Model: Goal Zero Yeti 150 Solar Generator / Battery

• Cell Type: AGM Lead-Acid
• Peak Capacity: 168Wh (12V, 14Ah)
• Lifecycles: hundreds of cycles
• Shelf-life: Keep plugged in, or charge every 3-6 months
• Fuses: 20A, user replaceable fuse
• Management system Charging and low-battery protection built-in
• USB port (output): 5V, up to 2.1A (10W max), regulated
• 6mm port (output, 6mm, green, hexagon): 12V, up to 10A (120W max), regulated
• 12V car port (output): 12V, up to 10A (120W max)
• AC inverter US (output, 60Hz, modified sine wave): 110V, 0.7A (80W continuous, 160W surge max)
• charging port (input, 8mm, blue, circle):14-29V, up to 5A (60W max)
• Operating usage temp.: 32-104 F (0-40 C)

Model: Boulder 15 Solar Panel

• USB Port: 5V, up to 1A (5W max) regulated
• Solar port (blue, 8mm): 14-22V, up to 1A (15W max)
• Rated Power: 15W
• Open Circuit Voltage: 18-22V
• Cell Type: Monocrystalline

Manufacturer Website:
http://www.goalzero.com/p/164/goal-zero-yeti-150-solar-generator
http://www.goalzero.com/p/20/boulder-15-solar-panel

Deployed!

(Tripod is a repurposed surveyor tripod.)

Next post on this subject will discuss the results of this experiment....

Wireless Operational Link for the Field (WOLF) - A Need for Wifi in the Field

In this post I will discuss the rationale, architecture, and results for developing a portable wireless rig for scientists conducting fieldwork. I should first mention the need for wireless connectivity to research plots is not a new concept. At the Toolik Research Station, "wireless for the final mile" has been almost a holy grail wish list item. With wireless connectivity researchers could deploy sensors to monitor their work, but also could use the internet connection to find reference documentation while working in their plot. The realization that all equipment as well as equipment manuals to research references must be prepped for offline use is almost unthinkable to a smartphone society that takes constant connectivity for granted. Yet even while the need for internet connectivity is justified, the cost of surveying, designing, deploying and maintaining a permanent solution has been prohibitive in both personnel availability and cost.

Ok. I will back up a bit now to explain a few things not necessarily apparent to those not directly involved with fieldwork....To fully understand what a "research plot" is, I will demonstrate here:

For research that involves the monitoring of vegetation cycles, gas release (such as co2) from the soil, and other measurements of interest; researchers set up experiments on a section of ground called a "research plot." The plots must be setup in coordination with the station's GIS staff in order to comply with Federal permit regulation of protected land issues as well as preventing one scientist to set up shop on top of another scientist's experiment. For reference, the map below shows the established research plots located near the Toolik field station. Notice the concentration of plots south of the lake. This is "the next mile", which also happens to be located over a reasonably-sized hill comprised of solid rock (not wireless signal friendly).

If you are interested in the comprehensive overview of the Toolik plots, please refer to the GIS informational page for plots/permits.

An actual research plot up close looks something like this:

This plot in particular, utilizes a greenhouse. The location of this plot is in the middle of the mass of yellow dots south of Toolik Lake.

At this point, it should be apparent why wireless access to research plots in an area as remote as the Toolik station is desirable but presents challenges. It is also worth mentioning that wireless to "the last mile" is a fairly easy task compared to delivering internet connectivity to plots located 20 miles away from camp. Which, also happen to be accessible only by small helicopter.

Next post on this topic will discuss the design I came up with for the WOLF rig...

Time to play blog catch up!

The Arctic Glass project has been moving along quite well, and I finally am able to sit down and document via this blog. Not only has the project weathered the storm that is Google's removal of Google Glass from the public market, but also now includes an Internet of Things (IoT) component. The IoT inclusion was to demonstrate capabilities of real-time data monitoring and collection using only consumer-grade commodity hardware (Intel Edison microcontrollers + Google Glass + Freeboard dashboard). My second visit to the Toolik research station in Alaska has also yielded new insight applied to real-time data monitoring in remote locations. I will be adding the various posts with more detail on these topics during the next week or so. For now, here is a pic of the portable wireless network I designed. The configuration is minimal and does not require networking IT assistance, so virtually any researcher could easily setup for themselves. The connection to the station's wireless backbone is through AP mode only, so no additional IT skills are need beyond what would be required to setup a basic wireless home router. The rig is solar-powered and with a -15dB high gain consumer-grade antenna, was able to extend wireless signal to the majority of research plots at the station! A second wireless rig could have picked up a few more on the other side of the hill (solid rock make wireless signal very angry). You can see the field station in the lower left corner of the picture. More details to come on the rationale, architecture, and results of this experiment and others very soon.....