The paper aims to improve both user experience as well as
business practices by using IoT enabled devices in retail space where the
movement and reshelving of products can result in major reconfiguration of
product signage and labels. The paper presents a detailed study of BLE channel
characteristics, followed by the design and implementation of Smart LaBLEs
which acts as a decentralized IoT hubs.
Key Points
- The paper mentions that it not necessary to determine the physical
coordinates of each object in the environment; instead it is only necessary to
order the objects in terms of nearness to the scanning device.
- Analysis regarding BLE channel covered in paper that
define the design space of proximity- based systems:
1.
The distance between a scanning device and the
nearest BLE tag must be less than twice the distance between the above tag with
the adjacent ones.
2.
Long-term averages of RSSI values do not produce
accurate estimates of the nearest tag due to channel fluctuations.
3.
Instantaneous RSSI values collected from tags
with a small window (< 1s) are sufficient to pick the nearest tag assuming
the antenna of all tags are oriented correctly. Performing averages over short
windows can smooth out fluctuations due to tag orientation.
4.
Same type of tags with new batteries can produce
different signal strengths. Tag orientation also affects the nearness ordering.
5.
Change in transmit power does not change the
results.
- Use of IoT hubs to adopt the decentralized architecture
and potentially allowing bandwidth and energy conservation in IoT systems.
- For the Smart LaBLE system, it is assumed that the
relevant product information
could be transmitted in the initial advertising message sent
in passive scanning mode.
- For passive scanning mode of communication, the smallest
and the largest packet takes 80 us and 328 us transmit times respectively.
- Each Smart LaBLE is attached to a central computer for
data collection to generate the results presented in this section/shelf. MAC address
in the tag helps identify the particular item of product types.
Strengths
- Verification with most popularly used topologies: circular
and linear. Other variations: distance between the tags and scanning device, advertising
period and the transmit power of each tags.
- Evaluation of the Smart LaBLEs shows a false detection
rate of approximately 1%
- Conservation of energy
and bandwidth due to reduction in the frequency of advertising messages sent by
tags.
- Automatic configuration of associated displays by Smart LaBLEs
thereby removing the hassle of manual updates to the signage.
- System is able to maintain the info about the number of
products left in the shelf of the tagged items.
Weakness and Discussions
- Time to hear advertising messages from all products is
over 3s when using 12 products. Will it work in real life retail environment
where the number of products will be a considerably large?
- Dynamic transmit power control can be leveraged to improve
the efficiency of the system.
- In case of advertising message loss, dynamically changing
the advertising time period might improve the system more.
- There is no mention of tracking of products in case of failure
of BLE tags.
Very nice description and understanding. Neat paper but could we avoid this problem and simply scan the product during stocking?
ReplyDeleteNot sure which particular problem are you referring to? Do you mean the problem with faulty beacons/tags?
DeleteI mean the entire problem! As we stock a product, we just scan it against the LCD/scanner display to pick up the code.
ReplyDelete