Diverse LPWAN specs available for different IoT applications
Vincent Mao, Taipei; Willis Ke, DIGITIMES [Wednesday 20 September 2017]
Traditional telecom is suitable for long-range coverage but involves high power consumption, and the coverage capability is also largely affected by the density of base stations deployed. Now in the IoT (Internet of Things) era, many application scenarios require transmission of small data volume, creating an opportunity for Low Power Wide Area Network (LPWAN) to emerge rapidly for extensive applications in smart manufacturing plants, smart cities and the agriculture, fishing and livestock sectors.
As long-range transmission of small data volume with lower power consumption does not involve sophisticated technologies, many LPWAN solutuions have been rolled out, with the most notable ones including NB (narrowband)-IoT solutions using a licensed spectrum, and LoRa and SigFox solutions operating in an unlicensed spectrum.
Kevin Yang, managing director of Taiwan wireless communication products maker GemTek Technology, said that with a transmission speed lower than than 200kpbs, LPWAN has a transmission range of 3-5 kilometers in urban areas and 10-15 kilometers in suburban areas, which can fill up the deficiency of short-range wireless local area networks WiFi and Zigbee. Further, its long-range transmission with low power consumption can also address the shortcoming of high cost seen in traditional cellular communication networks.
Lin Yu-hsiung, a senior product manager at Taiwan industrial PC maker Advantech, pointed out that low power consumption is extremely crucial to IoT applications, as sensors deployed in many IoT application scenarios are widely scattered, with some even on high mountains or in uninhabited areas. Initial deployment of IoT devices in such sites would be hard to complete, Lin continued, and follow-up inspection and maintenance of the devices would also involve high personnel cost. Accordingly, he stressed, low-power consumption of data transmission modules plays a critical role in determining whether the installed IoT systems, usually with long life cycles, can effectively utilize the LPWAN's advantages to collect data at low cost.
SigFox not on the same par with LoRa, NB-IoT
GemTek's Yang opined that it is a wrong practice for people to put LoRa and NB-IoT on the same par with SigFox, reasoning that the latter is just a global LPWAN service platform operated by French IoT startup SigFox, instead of a common transmission protocol. By partnering with telecom firms around the world, SigFiox renders paid IoT connectivity services to terminal users through cellular wireless networks.
Just like Apple setting specifications and regulations for partners in the entire iPhone supply chains to follow, SigFox has worked out a complete set of standards governing its entire LPWAN ecosystem, including software and hardware, for cooperation partners to observe. Accordingly, all the participants in SigFox LPWAN service platform should adopt the same software and hardware architectures to facilitate integrations and connections, according to Yang.
In contrast, like Android as an open-source mobile operating system, LoRa is an open, long-range, low power wireless platform allowing any companies interested in the technology to make operating deployments, Yang said, adding that though LoRaWAN is a protocol specification built on top of LoRa tech developed by LoRa Alliance, the open platform can help to inspire innovations by all participating parties to make LoRa technologies become more advanced.
LoRa remains the mainstream solution
At the moment, LoRa remains the mainstream LPWAN solution and enjoys significant market demand, Yang continued. He analyzed that SigFox LPWAN is a closed system unilaterally dominated by the French company, limiting its technological development. Although also using unlicensed spectrum, LoRa can offer diverse technological integrations through cooperation partners to achieve better anti-jamming performance and higher transmission efficiency, according to Yang.
On another front, as NB-IoT, based on standards set by International Telecommunication Union (ITU), adopts licensed spectrum that can better resist jamming, it is more suitable for the application scenarios that require highly reliable transmission and wider service coverage. But the cost for incorporating NB-IoT solution will be higher, as the solution has to be brokered by telecom firms, Yang noted.
While some wonder whether the competition in LPWAN specifications will repeat that in 4G specifications, Yang said that different specifications have different advantages and are suitable for different application scenarios. For instance, he said, SigFox boasts the advantages of standardized service platforms and wider-area applications, while LoRa can perform better in dedicated application networks and allow users to build their private and closed application networks at lower cost than other LPWAN solutions.
Some Taiwan telecom firms have started to operate LPWAN data transmission services using NB-IoT technology, but such technology is not applicable to many IoT application scenarios where telecom signals become quite weak. In this regard, LoRa Gateway can be applied to help users build private telecom networks to collect data at lower costs. In addition, LPWAN will not necessarily have to compete with LTE cellular networks and local area networks (LAN), and instead, they can complement each other to better adapt to multiple IoT application scenarios, Yang concluded.