5G will require, to achieve the targeted high bandwidth a significant portion of the spectrum, in the order of 100+MHz. In turns this implies the use of much higher frequencies 20-100GHz to accommodate that spectrum (also given that lower frequencies are already assigned) and these higher frequencies have very low propagation strength. Hence the need for small cells 100m and less. This is particularly so in a urban environment where high usage is expected and having smaller cells results in more bandwidth per user.
Smart Cities make use of the connectivity infrastructure as an enabler to govern several other infrastructures.
I like to address two aspects, IoT data harvesting and citizens based communications infrastructure, although there are several others like supporting self driving cars, smart health care, manufacturing and retail.
- IoT data harvesting
Cities have a multitude of sensors already deployed and more will follow. They are different in technology, sensed parameters, maintenance and communications requirements, from safety and security cameras with a varying range of throughput (steadily increasing) to pollution sensors that generate few bytes per day. More will be deployed in the next years and there are plans to develop “sensors” infrastructures, using telecom Operators infrastructure (using cabinets as hosting premises). Furthermore, municipalities have adopted/are adopting an Open Data Framework policy pressing private citizens as well as private business to share data, thus further increasing the amount of sensors and related data.
Platforms, like FIWare, provide a secure and affordable environment to host data and make them available to third parties applications.
The harvesting part takes place in a variety of ways, depending on the type of sensor, the available connectivity and its ownership. This variety is today met by protocols like LoRa, and SigFox. Actually other protocols are also being used fitting the specificity of the sensor and its location.
Additionally, there is a trend toward creating active dynamic mobile harvesting systems to capture passive sensors (including passive RFID). Buses are being equipped with WiFi, citizens smartphones provided with NFC both represent ways to harvest data from sensors disseminated in the urban environment.
5G is expected to work as an umbrella encompassing all (or most) of the communications protocols that are being used today. In several cases it offers better alternatives to what is being used today and from a smart city perspective the point is the cost of replacing an existing communication (data harvesting) system with a new one. This point will be addressed mostly from a cost perspective (both immediate cost involved in the substitution and operational cost). Clearly, new sensors that will be deployed once a 5G coverage exists (with a communication protocol meeting the needs of data harvesting for that particular sensor) will be using a native 5G protocol.
A few sensors will have more sophisticated networking capabilities, ie they will be able to communicate with one another, creating a network at the edge. This will be supported by the 5G architecture. Some of these sensors may form part of a mobile edge computing infrastructure (that might be the case for vehicles).
- Citizens based communications infrastructure
A growing number of citizens have smartphones, particularly the younger generations and in Westerns Countries, although the trend is worldwide. In the next decade the penetration will grow everywhere. The life time of smartphones is relatively short, from less than a year to 3 years, hence it can be expected that once the first 5G enabled smartphones will become available, somewhere in the first part of the next decade, within 3 years the new 5G enabled generation will be in place.
However, one can notice that some of the features of 5G are already possible with current smartphones generation, like tethering another device to serve as an access gateway and communicate peer to peer with another device (including with another smartphone).
A few tweaks to the software (and people are used to updated their smartphone software periodically) and current smartphones can start playing the game as the future 5G phones.
The opening of the sensors within the smartphone to applications is already happening, at least partially, and again it is a matter of a new software release to make the smartphone sensors even more accessible.
The creation of local networks at the edges, based on smartphone is mostly a matter of upgrading the software. This can transform them into network nodes, enabling the creation of mesh networks. They might even act as servers, as well as distributed cloud at the edges.
To what extent these possibilities will be implemented is also depending on the level of openness granted by the Operators. As an example, to use my phone as a tethering device my Operator would charge an extra fee. And it is not allowing tethering abroad, not even paying an extra fee!
Cities have the potential to deploy small cells, leveraging on other infrastructures, like light poles, park meters, garbage bins, red lights … and can create network at the edges.
5G can leverage on these networks and some form of PPP –Public Private Partnership- can accelerate the deployment.