The Wireless Network Evolution 

For the last 30 years we have enjoyed the increasing benefits of wireless networks giving us the power to communicate remotely. With the advent of the IoT, wireless connectivity has moved beyond linking just humans, to the creation of networks which integrate people with their environment via sensing and actuation systems. Gas Sensing Solutions (GSS) has been at the forefront of the IoT movement with their ultra low power LED NDIR CO2 sensors

More discussion on this later…

First a review of the wireless network evolution. The 80’s saw the introduction of 1G better known as analogue cellular followed by 2G, 3G,4G and now 5G. Analog cellular system standards were fragmented at the county level and purely focused on providing voice services.

GSM (2G) was the initial digital standard providing both voice and very limited data capability (SMS) and was the first “nearly” global standard. 3G provided enough bandwidth to give us mobile video although it was initially sold as a more efficient way of providing voice services. 44G acknowledged the need for low power Iot networks with the introduction of Narrow Band IoT (NB-IoT) and LTE-M (also known as CAT-M1) profiles.   5G will bring us networks that can be configured on the fly for different applications whether they be high bandwidth, low latency, high mobility etc but not necessarily all at the same time! Oh, and if this is not enough, the embryo of 6G is starting to form which is billed to integrated terrestrial and satellite wireless technology thus providing genuine global coverage …at long last!

A little more detail on 5G. This will be a hybrid standard which builds on legacy 4G (LTE) technology but also elegantly integrates WiFi and emerging Low Power Wan technologies such as Sigfox and LoRA. The 5G network will offer application and deployment flexibility in that the software used to program the network (SDN) will define the the characteristics of the service. In addition, 5G networks will “think” for themselves such that they will be able to self organise (SON) to accommodate changes in bandwidth and latency demand as populations move around during the day. In the event of an abnormal event, for instance physical infrastructure damage, the network will automatically reroute traffic to maintain services.

Power Consumption (and Supply) the never-ending challenge.

Mega Power

Cell Power

Scavenged Power

                                  

Whilst wireless technology develops in leaps and bounds it does so with the constraint of both power consumption and supply. Ever since the introduction of the mobile phone and apparently there over 80 million of them in the UK alone, battery lifetime has been a key care about. With the advent of the Iot where many of the end points are sensors often remotely deployed, low power consumption remains a key objective.  GSS CO2 sensors have become a compelling choice for companies manufacturing, environmental, medical, horticultural etc monitoring systems. These require miserly power consumption as the sensor end points are almost always battery powered. although energy scavenging systems are becoming more prevalent.

So why are GSS NDIR CO2 gas sensors so compelling? Well they feature ultra-low power consumption by employing   solid state, mid-infrared, light emitting diode and photodiode   technology. Specific performance benefits include power consumption of less than 3.0mW when performing two measurements per second and rapid stabilisation time of less than 2 second. This super low power consumption makes them ideal for battery and scavenging systems. GSS sensors being solid state, with an absence of fragile parts, are very robust and ideal for tough IoT deployments. Conversely traditional CO2 sensors use incandescent IR sources which require time to heat up, are fragile and tend to drift overtime as the filament emissions change due to the ageing process.

GSS designs and produces its CO2 sensor product range in Scotland. This includes the manufacturing of LED and Photodiode components emitting and detecting radiation at 4.3uM which is a prime resonant vibration frequency of the CO2 molecule.

The sensor unit comprise a bridge board housing the IR emitter source and sensing components plus a custom optical cavity into which the CO2 under measurement diffuses. By knowing the input energy to the LED source and the measured received signal strength at the photo diode, the level of IR radiation absorbed by the C02 gas can be calculated. GSS has developed and refined propriety temperature compensated signal processing algorithms to facilitate the CO2 gas concentration calculation.

GSS Sensors are easy to interface with standard Wireless Modules.

GSS Sensors require minimal physical connections. As shown above all that is required is Power and Ground plus a UART bus connection for interfacing to a range of industry standard wireless modules. The figure below shows a GSS CozIR LP sensor bonded with a Bluetooth module demonstrating just how compact such a wireless solution can be. The sensor module is powered by a 3V coin cell. We used a generally available APP to remotely display the sensor readings.

GSS are always on hand to offer our expert advise. Please contact us for more information.