The Internet of Things, or IoT, is probably the most rapidly growing technology area in coming years. Almost any kind of sensor, device or meter will be connected wirelessly to internet and cloud services. This enables remote follow up and control of various devices. Standardization of IoT technologies is ongoing and some of the technologies are already approved. The first devices are also expected to be in pilot use by the end of 2016.
Requirements for network technology
Quite many of the devices will be in places where mains power is not available or assembly without any cables has clear benefits. In these use cases low power consumption is mandatory requirement. Battery life time should reach several years instead of months or weeks. Required data transfer capability is however relatively low in most cases when for example slowly changing parameters are measured.
A network’s range is important feature as it determines needed investments. Network coverage is also important as many devices will be assembled in places like the basement of the building or parking halls where signal penetration is limited.
Purchase cost of devices and annual communications costs payed the network operators should be so low that connection of several devices to network and cloud services is attractive. Downward trend of several sensors prices makes them as well interesting.
List of coming LPWAN networks
There exist quite many candidates for low power wide area networks. These networks can be divided in two categories depending on type of frequency area used for service. Licensed frequency bands, which in this case refer to cellular networks and unlicensed bands which mean ISM bands. ISM is an abbreviation of industrial, scientific and medical radio bands, which are internationally reserved originally for other purposes than telecommunication. Usage of these bands do not require any license and devices are expected to tolerate more interfering signals than in licensed bands.
Three licensed band LPWAN technologies were approved by 3GPP in February. These are LTE-MTC, NB-IoT and EC-EGPRS. Abbreviations come from LTE machine type communication, narrowband IoT and extended coverage EGPRS respectively.
Several narrow band network technologies for IoT communication use unlicensed ISM bands. These are SigFox, LoRaWAN and Neul, NWave, Weightless -N, Weightless -P. The Last four are based on Weightless standard.
IoT networks in Europe
The most of the mentioned networks are still more or less in development phase and some already in deployment phase. Especially interesting cases are SigFox, LoRaWAN and EC-EGPRS. SigFox is already deployed in France, Spain, Italy, Netherlands, Belgium, Czech Republic, Ireland and partly in UK, Germany, and Denmark.
Orange has announced plans to launch LoRaWAN network in France in the first quarter of 2016. LoRaWAN network in Russia was deployed by the Lace company in autumn last year. There will be soon also networks in Belgium, Luxemburg, Netherlands and Switzerland.
Extended coverage EGPRS standard was approved by 3GPP in February and network manufacturers like Nokia and Ericsson will provide software updates in their GSM/GPRS networks to enable EC-EGPRS service. This will happen by the end of 2016. The first pilot devices are expected also be available in the end of the year 2016.
SigFox is based on ultra-narrow band technology with short burst and relatively low data transfer speed. Device can transmit 12 bytes payload at a time and maximum 140 transmissions per day having 100 bps transfer speed. This enables low power consumption and long battery life time. This kind of operation is suitable for applications where small amounts of data transmission is needed. Typical solution might be transfer of alarms and metering like water meter. Device control is also possible since downlink data can contain 8 bytes payload. Only 4 control messages per day is guaranteed so this is not intended for frequent usage.
LoRaWAN utilizes spread-spectrum technology with larger bandwidth than SigFox. Due to coding gains it can however reach similar link budget as SigFox. Transfer speed is higher than in SigFox and link is symmetrical, which allows higher downlink speed for device control.
EC-EGPRS technology is based on GSM/GPRS networks. No network HW updates are needed. Service can be added to existing networks by SW update. Extended coverage is achieved by utilizing concept of repetitions and signal combining techniques. By extending sleep cycles up to 52 minutes using eDRX significant power savings can be achieved. Data transfer speed 10 kbps is between SigFox and LoRaWAN.
LPWAN Pilots in Finland
SigFox and LoRaWAN network pilots will be deployed during this year in Finland. Connected Finland will build SigFox networks during this year. Digita and Actility have LoRaWAN pilot network in Helsinki area. There are only couple of base stations in both networks at a moment. Connected Finland using SigFox network technology say major part of the population will be covered by the end of the year. EC-EGPRS service SW update for GSM/GPRS networks will available during this year, but network operators have not announced any launches so far. The first devices are expected to be available for pilot use in the end of the year.
In near future myriad of devices – “things” will be connected to internet. Ericsson predicts that by 2021 there will be 28 billion connected devices. Many evolving network technologies will compete in this area and we will see pilot and commercial networks around Europe. It looks like there will not be any clear winning IoT network but several ones will be running coexistence. Connected Finland’s SigFox rollout will likely be the fastest and others will follow.