# IPv6 Convergence for IoT Cyber-Physical Systems
## 2 Background
IP support is dependent on TBS size due to the larger overhead associated with IP networking [16]. * **LoRaWAN**: LoRaWAN is low power wide area network specification intended for wireless-battery-operated IoT devices in regional, national or global deployments [3; 17]. LoRaWAN targets key requirements for secure bidirectional communication, mobility and localization services. We detail the range of data payload capabilities in Appendix A[17; 18]. * **SigFox**: SigFox created an ultra-narrowband IoT communications system designed to support IoT deployments over long ranges, for example, in excess of 20 km between a client device and a basestation [19]. This company has adopted an operator model, essentially creating a cellular network for IoT devices. Ultra-narrow-band operation is achieved using channel bandwidths of approximately 1 kHz that transport data payloads measured in tens of bytes. SigFox has targeted licence-exempt spectrum for their product, namely the 915 MHz band in the US and 868 MHz band in Europe. SigFox's model is a cloud-based approach where data are passed to the backend server and customer portal directly; users must then implement callbacks to route the received data to their own systems [19]. Sigfox does not support IP networking. * **RPMA**: Random-phase multiple access (RPMA) is a bidirectional IoT communications technology developed by Ingenu that operates in the 2.4 GHz ISM band. Ingenu claim that RPMA coverage can extend up to 300 square miles, throughput of 19 kbps/MHz and an uplink link budget of 180 dB and 185 dB for downlink in the US. Citing security concerns, RPMA does not support IP connectivity. Instead, Ingenu choose to provide a REST API instead for data access [7]. * **WEIGHTLESS:** Weightless-P is a bidirectional communications technology that uses a combination of frequency-domain multiple access (FDMA) and time-domain multiple access (TDMA) operating using 12.5 kHz channel bandwidths. It was designed for use in the 169 MHz, 433 MHz, 470 MHz, 780 MHz, 868 MHz, 915 MHz and 923 MHz spectrum segments. It supports data rates from 200 bps to 100 kbps [6]. Two other variants are also available from the Weightless special interest group. Weightless-N is a unidirectional technology designed for 10-year operation using batteries with a 5 km+ range. Weightless-W was designed for 3-5 year operation using batteries but mainly targeted for use in \"white space\" spectrum, that is, generally described as the unused and available segments in the ultra-high-frequency band [20]. Neither of the Weightless variants support IP networking. * **MIoTy:** Developed by Fraunhofer-IIS, MIoTy is a telegram-splitting multiple-access wireless technology requiring a bandwith of 200 kHz. It fragments data packets into numerous subpackets or telegrams, and distributes them over time and frequency. MIoTy was designed to support up to 15 km range in flat terrain, up to 65,000 messages per hour, 407 bits/s, have enhanced interference-resilience features for use in shared spectrum segments, for example, 868 MHz, 915 MHz ISM bands via the time- and frequency-distribution approach, and support mobility up to approximately 80 km/h [8]. MIoTy does not support IP connectivity. * **IEEE 802.11 af:** The IEEE 802.11 af standard uses sub-1-GHz spectrum to extend broadband coverage to urban users. Unlike a cellular approach, this technology adopts a WLAN topology and was designed to use up to four bonded TV channels to achieve in excess of 400 Mbit/s data rates. This technology is better suited to neighbourhood WLAN-type deployments [21]. * **IEEE 802.11 ah:** IEEE 802.11 ah Task Group developed a new standard to address the particular requirements of M2M networks, which include a large number of power-constrained stations; a long transmission range; small and infrequent data messages; low data rates; and a non-critical delay. IEEE 802.11 ah was designed to support 1 MHz and 2 MHz channels for the IoT and home automation services.