The AIR System is a wireless point to multipoint system based on DOCSIS or LTE technology. Because of the high throughput and very high distances a single base station can cover it is often used either in rural areas or as a pre-ftth deployment.
The AIR System is often deployed in a manner where it serves rural communities with real high speed broadband. Such types of deployments are often in harsh conditions which means the equipment has to be as resilient as possible to weather and other conditions in order to ensure full connectivity.
In Q1 of 2017 our R&D has finished its research and started the testing phase of the 4th generation quality control testing equipment called “Complete test”. We were testing and tweaking the system until it was implemented into the production line at the start of Q4 in 2017. The aim was to ensure the transceivers at the end users premises would withstand any and all conditions which could influence the performance by simulating various situations that come into play with a live deployment.
The Complete Test is a complex system of RF transmitters and receivers, RF modulators, a multitude of sensors, frequency-adjusted radiant chambers with reflective barrier and receiving transmitting radiant antennas and temperature-controlled attachment for the AIR Transceiver.
Tests are being performed in 3 stages:
· Simulation of a deployed system in real conditions
In a test cycle more than 72 measurements are made in a temperature range between -35 and 70 degrees centigrade of which 18 are measured over a longer time slots while the rest have a single point of measurement. Each transceiver is equipped with a unique QR code so it can be tracked through the production and testing phase and identified at any single point. The complete testing procedure is adjusted for every project because each project has its unique technical specifications and regulations.
All AIR transceivers are being tested at the limit of their capabilities. On the downstream side, the MER setting is set at the minimum recommended value for a specific modulation profile (QAM2048, QAM1024, QAM256, QAM64,..) while on the upstream side the transmitting power is set just below the saturation level of the transceiver. This way, any deviation from the threshold values are detected before the product is shipped to a client and a faulty or not optimally working transceiver can be returned for reconfiguration. The testing process is fully automated and all products are traceable while results are permanently saved in our database.
Standards, which are supported by the Complete Test are:
· DOCSIS / EuroDOCSIS (2.0, 3.0, 3.1) Data Over Cable Service Interface Specification
· DVB-T / T2 Digital video Broadcasting Terrestrial
· DVB-C / C2 Digital video Broadcasting Cable
· DVB-S / S2 Digital video Broadcasting Satellite
· LTE / LTE-A Long-Term Evolution 4G broadband cellular network technology.
· WiMAX Worldwide Interoperability for Microwave Access
The purpose of the Complete Test is to test the transceivers to make sure outside influences are not in any way impairing the transceivers performance.
Some of the tests which we are performing are:
· Response to temperature change or long term extreme temperature,
· Supply voltage stability,
· Current load,
· External frequency interference,
· Impairment due to beam reflection,
· Rx sensitivity,
· Tx power,
· Performance stability of the detector which executes a shutdown in case of faulty performance of a transceiver (oscillation,…),
· Frequency stability of local oscillators,
· Transient amplification of the receiver and transmitter,
· Noise-figure analysis for receivers,
· Modem connectivity,
· Impact of digital modulation schemes,
· Receiver and transmitter efficiency in regard to SNR, MER, BER,FEC,
· Frequency path phase noise (PN),
· ICMP analysis
After the transceivers went through the quality control process the complete system (Outdoor and indoor BS equipment, DOCSIS/LTE equipment,..) are assembled in a laboratory environment and a test of the whole system is performed with sample transceivers in order to ensure the system works within parameters as a whole.
To conclude, quality control is one of the key stages of the manufacturing process of our transceivers. We invested a lot of time and resources in the QC system due to our philosophy that it does not matter where and under what conditions our equipment is connecting a customer. The connection has to be FTTH-like in every condition and situation and we are putting extreme efforts into ensuring that it is exactly that – FTTH-like.