Smart City: Low Power Network
If innumerable devices, machines, buildings and objects are to be interconnect in an Internet of Things, then a reliable, inexpensive and energy efficient mobile network is needed.
When speaking of the Internet of Things (IoT), people generally think of the much vaunted refrigerator that automatically places an order for more milk – or other gadgets that are connected to the Internet, which are supposed to bring benefits that are not always plain to see.
The «Internet of Things» is, however, anything but a simple gimmick. Devices, machines, buildings and objects of all types, from letterboxes to bicycles that are equipped with sensors and are interconnected with each other, form the basis for the city of the future: The «Smart City» reacts intelligently to environmental conditions, optimising, for example, the flow of traffic and checking the status of water hydrants and the fill level of recycling containers. The sensors used may be temperature sensors, energy meters, proximity or rotation sensors. The Smart City also encompasses thermostats, switches, dimmers, pumps, valves, motors and other technical equipment that can be controlled electronically and which can intervene in controlled circuits.
To ensure all this can function, the devices and buildings require a stable Internet connection. This should be able to be set up as inexpensively as possible, feature the widest range possible and function using as little energy as possible. Cabling is out of the question due to the costs alone – and mobile objects can’t be connected using cables in the first place. While WiFi is inexpensive, its range is limited and we have to remember that this is all about interconnecting countless elements that are distributed right across an entire urban conglomeration. Mobile telecommunications, in turn, require each and every device to be fitted with a costly SIM card, and are comparatively energy hungry – far from optimal for battery-operated sensors. However, WiFi and mobile telecommunications provide a high bandwidth instead.
Some processes, such as periodic temperature measurements, for example, function with low data volumes and do not depend on speedy data transmission. A Low Power Wide Area Network (LPN or LPWAN), which operates using frequencies in the radio range and a very low transmission power, are highly suited to applications like these.
There are several types of LPN technology, such as Sigfox, being used at different points. However, a standard that was developed by the LoRa Alliance and which enjoys broad support is now becoming increasing established. LoRaWAN uses the licence-free SRD band, offers bidirectional data communications at 0.3 to 50 kbit/s and enables a range of around 2 to 15 km, depending on the surroundings. The entire data traffic is encrypted using 128-bit AES. A LoRaWAN module for sensors only costs a few Francs, and consumes so little power that the battery will last for up to five years.
«The first Smart City in Switzerland is St. Gallen.»
The first Smart City in Switzerland could be St. Gallen. The municipal electrical utilities there have been testing a LoRaWAN-based LPN there in cooperation with Effectas and IBM Research Rüschlikon for a period of six months. And successfully too, because a submission was made to the city parliament at the start of July 2016 to cover the entire urban area with the Low Power Network.
And Swisscom has been involved right from the start. The company has been part of the LoRa Alliance since the start of 2015, and has already launched pilot installations in Zurich and Geneva in 2015. Swisscom Broadcast set up the first receiver station on Üetliberg. According to Alexandra Reich, EVP Solution Centre Mobility Enterprise Customer at Swisscom, there are now more than 35 stations in operation. The aim is to provide at least 80% of the population with outdoor LPN access by the end of 2016. To achieve this, around 300 receiver stations will be required across Switzerland. The outlay for constructing the network can be kept to a minimum, because it is often possible to use existing stations operated by Swisscom Broadcast. Total costs of less than CHF 10 million are expected for basic coverage.
«LPN is the solution for the Internet of Things»
The interest in the Swisscom LPN is considerable. Well over 100 companies, public authorities and universities were interested in the pilot test. And a whole series of specific projects have been set up. Two examples:
FeedbackNow is offering a real-time solution for surveying customer satisfaction directly at the sales point. Customers can share their opinion of the quality of service with the help of the «Smiley Box». This voting machine is based on LoRa technology – and for FeedbackNow, it is providing a competitive advantage when it comes to installation and operating costs.
«MyLock» from Swissprime Technologies is an intelligent locking solution for locks on doors, furniture, letterboxes and so forth. The locks are operated from a smartphone by using Bluetooth or NFC. The LoRa technology is being used in a first prototype for the transmission of operations from the lock to the Cloud, and for remote access.
Along with the network itself, Swisscom is offering advisory services and the web-based LPN Connectivity Management Platform (CMP) along with turnkey solutions. For example, «Smart Parking» for operators of car parks. The individual parking spots are equipped with wireless sensors and transmit the occupancy status via LPN. The management platform processes the data and sends it to the car park management or a mobile app, thereby turning the endless search for a parking spot into a drive to a specific space.