Private Mobile Radio networks (PMR) have been used so far by companies or government entities that needed mobile communications with extremely high levels of reliability and security. Today, 4G makes PMR a pertinent, valuable, and affordable option for other industries, especially the industry sector. Operators would thus be wise to develop 4G-based PMR solutions.
Industry 4.0: a multiplicity of networks for a variety of usages
As a matter of fact, in large industrial sites, there is a combination of several networks. Each one is used to cover a specific and different technological need:
- a TETRA network for outdoor mobile conversations (for field or production line workers)
- a DECT network for indoor telephone communications (for office workers)
- a WiFi network for indoor and possibly outdoor data communications
- a CCTV network for surveillance and monitoring
- and today, for the specific purpose of adding business value through the automation of or the exchange of data between manufacturing equipment: a network adapted to industrial IoT and machine to machine needs.
It is obvious that reducing all those different networks is today a vital need for any operator or industrial actor, concerned by security aspects, as well as productivity and cost enhancement. However, these various networks result from various critical and mandatory needs of the business activity. Remotely taking control of a machine will require very little bandwidth but extremely low latency, while collection of data for preventive maintenance may require a somewhat higher bandwidth but no immediate response times.
This is exactly what a 4G network, and later on a 5G network, can be used for:
- first, to allow the easy and fast substitution of all the various analog and digital networks into one unique physical network,
- and second, to offer an infrastructure capable of supporting endless use cases with their related SLAs for each scenario and unique requirements
Multiplicity increases complexity and operational costs
Integrating, ensuring the interconnectivity, and managing simultaneously all of these networks require expertise and time, not to mention a dedicated network monitoring and supervision center for each network. Obviously, the resources should be skilled in multiple technologies. Those resources may not be easily available. Such activities are therefore usually outsourced to a managed service provider, at a consequent additional cost.
Using multiple networks also increases the risk of a security breach. Each network requires its own means of protection against malicious attacks and its own monitoring solutions and processes. Ensuring an adequate level of security requires budget and, again, expert resources.
And finally, these networks do not all support the same equipment. Equipment used in the field for PMR is often ruggedized, easy-to-use handheld radios. They are designed to be highly resistant and to transmit voice but little else. Other usages, or the need to move outside the PMR zone, will need switching to another device. Managing multiple devices means investing time and resources in:
- dealing with multiple suppliers,
- handling technical issues specific to each device,
- managing replacement and stocks,
PMR over 4G is a perfectly relevant option to serve industrial sites
4G is an opportunity for industrial sites to combine all of their different network usages over a single private network. This comes with obvious benefits:
- only 1 network to monitor and manage equals less complexity and lower management costs;
- possibility to offer several QoS and traffic profiles to fit each and every use case in the industry requirements.
- 4G comes with authentication and encryption features included by default within the LTE standard.
- 4G natively supports both voice and data. PMR services – usually voice-only – can thus be enriched with additional data services (e.g. transmission of photos or videos).
- the coverage offered by 4G is wider than DECT or WiFi. It is therefore perfectly suited to both indoor and outdoor uses.
- 4G-compatible devices will offer a wider range of usages than the traditional ruggedized MPR devices. They facilitate mobility too, both on and off-site. Harmonizing the number of devices used within a company or a site will reduce costs, if only in management time.
Why should an operator propose PMR?
As exposed previously, a PMR main advantage is the capability to replace various networks, various technologies and various usages into one unique network, supporting all the above. Furthermore, new features like Network Function Virtualization exist on 4G, and network slicing is to be introduced by 5G networks. It will thus be possible to offer, on one unique physical network, different SLAs and technical thresholds according to the active use cases deployed on this network. Hence, for example, a hospital will be able to perform a medical file transfer session while hosting a critical surgery, simultaneously.
In the countries where 4G is widely deployed, PMR can be introduced as a service with some limited hardware investment and mostly activation of software features from the core network vendors. The operator does not need to maintain a separate network, with its own operational teams, to serve PMR needs. Its CAPEX and OPEX are shared over numerous customers thus reducing costs per customer.
PMR could be offered easily using various scenarios, ranging from virtual network hosted by the operator, deploying limited small radio cells for radio coverage enhancement, or deploying a reduced standalone core site directly in the customer premises.
Up to now, PMR has been cumbersome and costly to deploy and maintain for an operator. Today, with the native features of 4G, and the future features of 5G, operators are in a position to propose enhanced PMR functionalities, with limited additional investments. The industry 4.0 is a prime target for these services as it will greatly benefit from the combination of all of their usages into a unique network.
