At the start of any field science effort, a set of critical initial factors need to be addressed by the science team, before the wireless network guidance in this wFD knowledge base will be of use. All content on this Wireless Faster Data for Science knowledge base supports the design and employment of wireless networking subsystem (see definitions & lexicon below) - this site assumes you know your science mission and the data you need to collect and manage.
Definitions & Lexicon: To make sure that the information on wFD will be of use, some common terminology is important - especially because field science efforts come from a wide range of disciplines, involve many different kinds of practitioners, and serve many different purposes.
The field is defined as any location where you will collect data, from which you will employ a wireless capability, to span the wide-area network (WAN) between your data collection LAN (if any) and your destination LAN.
Your scientific workflow is a description of the data management process of your science activity - a description of the steps by which data collected in the field is converted into scientific results and information by your field science system. Your scientific workflow is the set of activities performed by the entire set of components comprising your field science system.
Your field science system is defined as the set of components (parts, communications between parts) which transport, gather, store, combine, and process data in support for the scientific purpose of your workflow. Everything necessary for the system to function, the data, sensors, fiber optics, cellular antenna, compute, sources of electricity, etc is a component of the field science system you are building is contained in this set. Your project may own and/or control some of the components in your system, or you may depend on components (such as a cellular network) which you do not own or control, but upon which you depend, and therefore these also are part of your field science system.
Your field science system is comprised of two subsystems:
- your scientific subsystem - the sensors, analytics, data analytics, controllers, compute, weatherized cases, and any other component you use to gather and produce data, regardless of how data is moved from the field to
- your wireless networking subsystem - the antenna, power, caching, and anything else you use to use one or more wireless technologies to connect your scientific subsystem to your destination LAN.
Before you can identify, deploy and operate your wireless networking subsystem, you need to first have a solid sense for how your science campaign will generate and use data, and what performance characteristics your scientific subsystem must meet, in order to make the activity productive. You may have components (such as batteries) which are common to both scientific and wireless networking subsystems. That is ok! These dual subsystem components create shared dependencies between both subsystems -- and identifying and designing for these dual subsystem components is an essential reason for the system framework we employ in the "starting conditions" design effort.
Factors defining the science ve worked out include:
1) Starting condition questions that will help describe your field site communications:
- Where geospatially are you deploying sensors and what temperature, pressure, meteorological, electrical, radiological, solar, humidity/moisture exposure or other environmental conditions will your field system system components operate under?
- What legal, permitting, safety or other organizational constraints exist - can you access the field site freely, or do you need to obtain permissions or is access prevented at some points of due to risks (such as avalanche in the mountains)
- Who owns the field site and for how long will you use it? Can you modify the site (such as by using concrete for antenna pilings) and how must the field site exist after your science activity is completed?
- Are there buildings, obstructions, Line-of-site considerations?
- What physical security considerations exist? Does equipment need to be protected against theft or damages?
- Are there factors that influence availability of radio frequency use - licensing or RF exclusion areas? Is the area covered by existing commercial or private cellular or other connectivity options for which you have access?
- What infrastructure for power, communications, storage, or site operations exists at your field location?
- What other activities or stakeholders are making use of this field location, and what kind of communications or interactions does your activity have with them?
2) Starting condition questions that will help describe your scientific workflow:
- At each step in your data analysis pathway, how should data move from the point of generation (usually a sensor), to points of consolidation & caching (such as data loggers), to points of analysis, to points of analysis, dissemination and long term storage?
- Will your data be transmitted to a single location or to many?
- What is the amount of data generated per sensor type per unit of time?
- How much storage (both amount and operational time)
- How is data reduced and processed. How quickly and how often do you anticipate getting data delivered to your analytic/compute/storage resources and in what form? How much delay is acceptable in getting the data moved from the field for analysis? (milliseconds? minutes? days?)
- What happens if a sensor fails to collect, or the infrastructure fails to deliver, data to your analytic or storage resources?
- Is your workflow static or can it change based on results or other factors?
- Will your sensors change location or data collection algorithms, methods, or timescales? If so, based on what data or messages, and what is the basic logic?
- What kind of cyber security restrictions exit and what kind of identity management/trust mechanisms do you need to either comply with, or need to create in order to protect your data and analytic environment?
3) Starting condition questions which will help describe your scientific subsystem:
- How many sensors and/or other devices will be operating as part of your data collection effort? Do you have a complete list of the sensors and sciences devices to be used as part of your deployment?
- Where will they be physically located? If you do not know exactly where these will be located, how will these sensors be located in relation to each other? Do you have a map or deployment design for the site?
- In addition to data connectivity, does your data collection infrastructure require control or other information to be provided to/from system elements supporting resource management (battery power, propane, or other consumables for instance) patching, position location, time synchronization, etc. What other information needs to move to/from the science system in order to maintain operation?
- Which of your science components will be operated without human supervision, and which will be operated with autonomously, or with periodic human interactions (such as to collect data, reboot if needed)
- Will sensors be capable of wireless connectivity directly, and if so, what kinds. If not, what other types of connectivity are available to support data movement? What kinds of built in connectivity do your science devices support?
- What kind of support, repair and replacement mechanisms exist for components in your field science system? What is the servicing schedule and maintenance needs of your devices? Do any of your devices use consumables? (sample media, batteries, etc?)
- What kind of electrical power (Volts, Watts, Amps, Phase, types of power connectors) do components in your science system require. What are the daily/seasonal power requirements of your science devices and what operational power modes exist? (can devices put into sleep mode, for instance?)
4) Budget and Other Factors
- What is your overall budget and how long is this science system going to be in operation?
- Who owns/controls/manages the components in your science system?
- What contracting mechanisms exist to support both deployment and sensor operation? Do you need to rely on a site subcontract to support construction or maintenance, for instance?
Documenting your Starting Conditions:
Here is a version of the above "Starting Conditions Questions" integrated into a standard project plan template.
5) Some other useful resources for this phase of your wireless journey:
1) The Earth Science Information Partners (ESIP) has useful information on site and platform selection here: https://wiki.esipfed.org/Sensor_Site_and_Platform_Selection