random phase multiple access (LPWAN) (RPMA)
Random Phase Multiple Access (RPMA) is one of several technologies for Low Power WANs(LPWAN) used in Ingenu. Other LPWANs include Low Range WAN( LoRaWAN), IEEE 802.11ah, LTE M2M( LTE-M), Narrow Band LTE( NB-LTE), and Weightless.
The aforementioned network technologies were developed for the Internet of Things( IoT) and machine-to-machine (M2M) communications. The aim of these technologies is to bridge as wide a range of distances as possible using radio technology. Unlike the other network concepts, RPMA operates on the ISM band at 2.4 GHz, although free- space attenuation at this frequency is much higher than at frequencies below 1 GHz. As a radio transmission method, RPMA relies on spread-spectrum multiple access( DSSS) technology, as well as transmit power control and high receiver sensitivity, which is -142 dBm. The total transmission budget is 172 dB. The data rate is 2 kbit/s, making it optimal for IoT applications. The range is up to 65 km for line-of-sight links and about 20 km for non-line-of-sight links.
In addition to the large area coverage, the method is optimized for lowest energy consumption to ensure the longest possible battery life. This is also ensured by a special connection protocol in which the access points ping the nodes to check their status.
The RPMA method is used in various LPWAN networks. Attempts are being made to establish the proprietary RPMA as an IEEE standard.