Improving the reliability of your wireless intercom
A wireless intercom is a telecommunication device that enables voice communication without the need for cabling between stations. A typical application for a wireless intercom system includes communication in a production environment, construction site or even in a retail space. A wireless intercom system may incorporate wired elements such as wired intercom or telephony feed. Often, a wireless intercom system will operate at either 2.4GHz (ISM) or 1.9GHz (DECT) band. In this article, we will be exploring how Maven’s wireless measurement can help improve and monitor the reliability of a wireless intercom system used in a production environment.
RTS 240 wireless intercom system. Credit RTS
Simplex vs Duplex Transmission
This case study will focus on two operational scenarios, namely, simplex and duplex transmission. Simplex transmission refers to the data flow in one direction, in this case, base station to the wireless Beltpack. In duplex transmission, the data flow is bi-directional, both base station and beltpack can talk and listen simultaneously. In this case study, the wireless intercom of interest would comprise of the following.
Base Station – BTR 240
Wireless Beltpack – TR240
Simplex transmission vs Duplex transmission
Simplex Operation
A common question when integrating/operating wireless intercom system would be the placement of the base station, and it’s wireless coverage range. In a simplex scenario, the roaming beltpacks would have to reside within the base station coverage zone to ensure a reliable link for communication. Below is an example of the measured coverage of the base station (BTR 240).
Measured wireless coverage of the intercom base station (BTR 240)
From the measurement above, users can then anticipate the real-world coverage range of the base station and plan the location of the wireless beltpacks respectively. Additionally, users can also adopt Maven’s wireless measurement to identify a suitable place to install the base station to achieve the maximum coverage area while considering installation constraints such as power or space.
Beltpacks that reside in the green zone will enjoy the highest reliability while it is not advisable to deploy wireless beltpacks to the red zone as connectivity is poor. In simplex operation, only the base station is transmitting data wirelessly to the beltpacks. Hence, a wireless coverage measurement of the base station will suffice.
Duplex Operation
For a duplex standpoint, the wireless coverage measurement of the base station will only provide half of the picture. In duplex transmission, the data flow is bi-directional, data are transmitted wirelessly from base station to beltpack and beltpack to base station simultaneously. Hence, the real-world wireless coverage measurements of the individual beltpacks are also required to ensure that the wireless intercom will operate reliably.
Measured wireless coverage of beltpack (Good Deployment)
If a beltpack is required to “talk” to a group, it is vital to ensure that the base station can receive a sufficient level of signal to provide reliable connectivity. The measurement above illustrates an example of a good deployment between the base station and beltpack. Additionally, we can also observe that the user does have effects on the real-world wireless coverage on the beltpack (coverage pattern is no longer isotropic).
Measured wireless coverage of beltpack (Poor Deployment)
An unreliable link will occur when the base station does not receive a sufficient signal level as depicted by the measurement above (poor deployment). Often, the base station would have a higher rated transmit power than the beltpack. In this particular case, the base station (BTR 240) has a rated transmit power of 200mW and the beltpack (TR 240) has a rated transmit power of 70mW (2.85 smaller than base station). Theoretically, the coverage range of the base station will be wider than the beltpack. Thus, the user will have to be mindful of edge cases where the wireless connectivity from base station to beltpack is reliable, but the wireless connectivity from beltpack to base station is unreliable (due to lower transmit power).
An unreliable wireless intercom system can cause more harm than good. System reliability is especially important for effective communication between users. This article has illustrated an example of how Maven’s wireless measurement can be adopted with a wireless system to quantitatively aid user to identify.
Ideal location for the base station (maximum coverage).
Wireless coverage range for devices (base station and beltpack).
Monitor connectivity links for simplex and duplex operation.
If you are looking to improve the reliability of your wireless intercom, contact us today!