Transmitting (and Analyzing) Data
The tasks of transmitting data and analyzing data are closely inter-related. Both these factors affect power consumption, which is addressed in a separate section.
For example, suppose the brood chamber of a single hive contains 32 temperature sensors, each one sampling the temperature every fifteen minutes:
- One data transmission-and-analysis scenario would be to transmit the 3,072 daily temperature data points from each hive to the beekeeper’s computer for further analysis.
- Another design choice would be to analyze the data at the hive and transmit a message reporting, for example, that “the brood chamber in hive number two is 63 percent full today”.
- A third design choice could be to report the percentage of hives in the apiary below, within, or above a desirable range on the Percent-of-brood-chamber-occupied parameter, together with providing the ability to obtain further details on the hives in each category.
The ability to analyze data at or near the hive greatly reduces the amount of information that must be transmitted and the power required to do so. This is a big advantage when either power or bandwidth is limited, and a must when cellular or satellite systems are required.
On the other hand, analyzing data at the hive or in the bee yard requires that a computer or microprocessor be located there, protected from the environment and from theft. It further requires that the data processing be fully automated. Also, the detailed data offer wonderful opportunities for exploring and discovering new colony phenomena and is of great value to researchers, monitoring system developers, and beekeepers of a certain analytical mentality. Consequently the detailed data should also be retained locally for later collection in at least some percentage of cases.
Currently available (2017) colony monitoring systems use a variety of communications technologies: Wi-Fi to a home network, Bluetooth to a cell phone, cellular data link to the internet, satellite communications to the internet; and combinations of these, such as Bluetooth from several hives to a cellular data link to the internet. Each of these has an initial cost and a monthly subscription cost.
In this arrangement, the sensors are wired directly to the beekeeper’s computer using a USB connection. The computer must be near the hive as the longest USB cord one can purchase is 15 ft. (5 meters).
Bluetooth products contain a tiny computer chip with a Bluetooth radio and software that makes it easy to connect. Various levels of Bluetooth have different power-range tradeoffs. Small short-range sensors may run off tiny coin-cell batteries for months.
Data may also be transmitted to the beekeeper’s computer using Wi-Fi. The range of some home Wi-Fi systems is limited to about 100 feet (35 meters) or so, depending on the intervening objects. This range can be extended with more powerful transmitters and with repeater nodes.
Cellular data service
Cellular data service offers coverage within a range of 10-15 miles from the nearest cell site.
In late 2012, ATT offered data plans for as little as $15/month for 250 megabytes of data.
Satellite data link
If one’s hives are beyond the reach of a cellular data service, then a satellite data link must be used.