MAY 28, 2021
Welcome to another update from Glass-Link! In this article, we are going to brush over the most commonly discussed features of popular LPWAN (Low Power Wide Area Network) networks and, compare them to the Glass-Link capabilities. Mainly, we will be focusing on LoraWANⓇ, as it tends to be widely recognized these days. Although noticeable, we won’t be discussing NB-IoT (uses licensed bands therefore low cost is highly discussable in many applications) nor Sigfox (downlink options are highly limited and thus it’s not well fitted to many solutions).
When we talk about LPWAN, we often focus on three key factors: low power, long-range and low cost (CAPEX and OPEX at levels of even less than 20 USD per node). And indeed, LoraWANⓇ offers all of them in one package. But these advantages present only one side of the coin. How about potential problems like ultra-low data rates, ultra-high latency (even many minutes, thus, in particular, there’s no possibility to build a real-time network with this infrastructure), lack of advanced coordination and environmental awareness, lack of easy to use yet powerful cloud services, where anyone can build a custom network in a manner of minutes?
In Glass-Link, we come ahead of all those problems and solve them in a very efficient and smart way. The Glass-Link network (in one of its flavours) utilizes a 2.4GHz ISM band. The main advantages of using a 2.4GHz band instead of sub-GHz bands are the air-time, closely related to network latency and, available bandwidth. Despite that, Glass-Link offers low-power, long-range, and low target costs, similar to LoraWANⓇ.
Considering the air-time (a time the packet is ‘spending in the air’ during its transmission), with Glass-Link, it can be as low as 93 microseconds for a 6-byte payload, assuming the range won’t exceed a few hundred meters (which is fine for most applications). Of course, the range can be extended to many kilometers while still maintaining the latency at levels of single milliseconds. This key advantage of Glass-Link over other LPWAN networks allows it to serve as a foundation for true real-time IoT networks and, all that at the cost of a regular LPWAN infrastructure.
The second important factor is the data rate. This obviously depends on the upper network layers and total bandwidth utilization, which includes protocolar overhead, encryption, FEC (Forward Error Correcting Code) coding, and so on. With Glass-Link, assuming little overhead is acceptable, the user can achieve up to 1Mb/s data rate in a single PTP (point-to-point) link. And this still assumes that FEC, CRC (Cyclic Redundancy Check), and PHY (Physical Layer) packet overhead are enabled. Technically speaking it is possible to use Glass-Link to transmit compressed sound or highly compressed video in real-time (we’ll provide more proof-of-concept examples later on the blog, so please stay tuned!). And what’s important, the data rate can be doubled by simply adding another link in parallel.
Glass-Link is a flexible IoT network. It can operate in modes the LoraWANⓇ utilizes (ref. LoraWANⓇ protocol), but it can do much more than that. Advanced coordination includes PCF (Point Coordination Function) that ensures QoS within assumed parameters, but also smart DCF (Distributed Coordination Function), which promotes asynchronous network access, therefore stimulates natural bandwidth distribution over the network. But even all that is not the end...
Glass-Link devices are aware of the surrounding RF environment. Considering the 2.4GHz band, the Glass-Link Node not only prevents packet collisions by utilizing LBT (Listen Before Talk) and FHSS (Frequency-Hopping Spread Spectrum) techniques (we’re not limited to the mentioned two), but it attempts to mitigate the interferences coming from WiFi or Bluetooth while trying not to disturb these services either.
In sum, Glass-Link seems to be the obvious choice for most applications. Of course, there are areas, where e.g. a receiver sensitivity of -140dBm or better (therefore very high single-hop distance) is necessary, and latency of tens of minutes or even hours can be accepted. There can be e.g. interplanetary or specific satellite communication, ultra-wide-area ground/field networks, etc. In those cases, a sub-GHz band LoRaⓇ link might be a reasonable choice. Yet this doesn’t have to be true either, as the lower range can be mitigated by increasing the transmit power in many situations. But the rapid development in any tech industry these days shows that most applications require fast responses and relatively higher data rates as well as unprecedented flexibility. Thus, we believe these aspects of an IoT network will be soon at the top of the industry needs.
We’ll provide more proof-of-concept examples demonstrating above mentioned Glass-Link aspects in coming weeks on this blog. Subscribe to Glass-Link newsletter to be promptly notified!
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