NB-IOT (Narrowband - Internet of Things), LoRa, and Sigfox wireless technologies have been getting a good deal of attention globally as the market for wireless matures in light of the prospects for billions of connections. Each of these technologies will likely play an important role in connecting devices, but understanding the features and differences of each is critical.
Narrowband IoT is the “clean sheet” initiative by 3GPP, the standards body that writes cellular standards, to address the needs of very low data rate devices that need to connect to mobile networks, often powered by batteries. There are fascinating geo-corporate-political elements at play also, and for more read Nick Hunn’s excellent piece, NB-IoT is Dead. Long Live NB-IoT.
In Nick’s piece he points out that the 3GPP specification for NB-IOT has two competing variants, Huawei/Vodafone vs. Ericsson/Nokia/Intel. Additionally, Ericsson has stated that older 4G infrastructure based on Alcatel will not be backwards compatible with NB-IOT. This means that thousands of base stations would have to be changed in the US for carriers to support NB-IOT. In light of that, most US Based carriers will stick to LTE-M.
So NB-IOT will be for simple devices that need to connect to an operator network via licensed spectrum. It is not available yet, and will likely not be until the end of 2017, and even later in the US. If you follow the company Sigfox, you will recognize this as the 3GPP community’s attempt to address the market space created by networks like Sigfox.
Read here for more information on the NB-IOT Physical Layer
LoRa is a modulation type. Just like BPSK or QPSK is the modulation of NB-IOT. A better term is LoRaWAN, which is the protocol for WAN communications when LoRa is used as a wide area network technology.
Read more: What is LoRa?
The most important differences between NB-IOT and LoRaWAN are:
- LoRaWAN used unlicensed spectrum. In Europe this means a 1% duty cycle, which limits the volume and frequency of traffic, as well as the ability of the base station to control the network and send traffic down.
- LoRa is a proprietary modulation system sold by Semtech corporation. They are defacto the only chipset manufacturer or license holder for LoRa. NB-IOT is based on standard modulation types, but as is typical of 3GPP, there will be other IP license holders asking for money eventually.
- LoRaWAN can also be used by non-mobile operator customers to implement solutions. The Things Network is a crowd sourced networking initiative using LoRaWAN. It should be noted that LoRaWAN networks interfere when more than one is operated in an area. Read more: Improving LoRaWAN Scalability
- NB-IOT due to much higher datarates, MAC sophistication, and higher power basestations will offer more advanced features for routing, multicast, firmware broadcast, etc.
No LPWAN article would really be complete without mentioning Sigfox, which is the company that awoke the world to the potential for IOT devices to use very low bandwidth connections. Sigfox is the most basic of the 3 technologies, with the key differences being:
- Sigfox has the lowest cost radio modules(<$5, compared to ~$10 for LoRa, and $12 for NB-IOT)
- Sigfox is uplink only. Though limited downlink is possible, it has a different link budget, and is very restricted.
- Sigfox is an end-to-end network and technology player.
Each of these technologies (NB-IOT vs. LoRa vs. Sigfox) each offer an interesting set of capabilities, though it should be stressed that today none are available at scale in most of the world. In the US, LTE Cat-M1 will be the first nationwide LPWAN technology to be deployed, in March 2017.
Technologies like LoRa will most likely be best used for “discrete” applications like smart buildings or campuses, where mobile network connectivity is not needed. The Link Labs Symphony Link system is based on LoRa and adds features needed by such customers.