How will TETRA system’s role change as the world migrates to 5G?  User needs and use cases will no doubt play a factor. 

TETRA has coexisted with different generations of mobile network from 2G to 4G. While mobile networks witnessed exponential popularity and expansion amidst users, TETRA saw its own share of growth. TETRA never faced competition from mobile networks. This PoV evaluates whether TETRA and 5G can coexist or if 5G will replace TETRA.

TETRA is a TDMA (Time Division Multiple Access) mobile radio system defined by ETSI TS 100 392-XX-XX series of specifications. TETRA has been a choice of services like Utility, Hospitals, Airport, Railways, Fire, Police, Warehouses and Mines and many more for more than last two decades. The users of PMR (Professional Mobile Radio) or PAMR (Public Access Mobile Radio) find TETRA quite useful. 

Comparison of TETRA and 5G Features

TETRA offers benefits and levels of service that mobile technologies and networks were unable to provide in certain scenarios. 5G network can handle  features such as network slicing in its own way. 

Blocking Traffic

There is no blocking in TETRA system, which implies that calls can get through in all the cases. The mobile networks of past were designed with certain amount of traffic calculations mostly supporting from 0.1 Erlang to 0.3 Erlang of traffic. The 5G mobile Technology enables the Network Slicing function. By the capability of network slicing, certain services can be given a better QoS (Quality of Service) or non-blocking traffic capability. 

Direct Mode Operation

While many of the calling features can be replicated in 4G/5G mobile networks, DMO (Direct Mode Operation) feature is one of the benefits of the TETRA Radio System. It enables the handset to communicate with another handset for a limited distance without involving the base station or other elements of the network. This is an extremely useful feature in case of disaster. Deployment of 5G system enables use of various commonly available phones and a hybrid operation that enables much higher network availability. The hybrid mode of 5G deployment offers great advantages. Hybrid mode is private 5G and Telco provided 5G network working in combination. This scenario is quite useful in the telcos deployed 5G SA (Standalone) networks.

Data Network

Support in instrumentation is another requirement that is expected from a communication network. The instrumentation requires much higher bandwidth as compared to voice. Most of the major users of TETRA are also deploying IoT or Industry 4.0. A new specification of TETRA 2.0 is introduced to increase the bandwidth of data on TETRA. Still the best-case bandwidth is few hundreds of Kbps. Apart from this, using TETRA radio for data communication from machines requires a modem that is too large and requires a bigger antenna due to lower frequency of operation. The 5G modules-based modems are quite small, and they support bandwidth of the several hundreds of Mbps (Theoretically 20 Gbps). Not only this, 5G can enable uRLCC, mMTC or eMBB type of services offering better QoS in such cases.

Hardware

TETRA has simple architecture, but it requires custom hardware, and maintenance team needs to inventory more spares. On the other hand, due to network function virtualization, 5G has the majority of the system requirement that are met using cloud or COTS products that makes supporting a private 5G network a less cumbersome activity.

Coverage

Coverage area may be challenging for TETRA for certain applications like police or fire that require covering a vast area. In such cases, having a captive or private network is a challenge. The challenge in using the existing mobile network has been the availability of channels during emergencies. With the 5G network, along with network slicing, a guaranteed QoS can be given to such services, plus an advantage of wide geographical coverage can also be augmented. This would save users from requiring separate spectrum with TETRA. There are 5G flavors like 5G CBRS and DECT NR+ that can operate in license-exempt band.

Applications in UE (User Equipment)

While TETRA radio handset supports a few applications, developing applications for such system is tedious. On the other hand, it is quite easy to develop applications for a 5G mobile handset working on commonly available operating systems. Moreover, 5G handset/UEs offer better cost benefits than the TETRA radio handset due to economies of scale.

Working with contemporary technologies

Increasingly, the workplace is using technologies like automation, AI, Analytics and IoT. To enable these technologies, a large bandwidth with low latency is required. Even machines used in normal or emergency operations require high bandwidth and low latency to implement automation and AI. Apart from these popular applications, there are a number of scenarios that  require two-way video streaming. In such situation, 5G is the inevitable choice.

Conclusion

While both technologies have their advantages, it really depends on the use case. In many of the applications where high baud (bandwidth) rate or low latency is important, 5G has an edge. However, certain applications like underground mines where voice communication is critical and LoS (Line of Sight) is difficult to obtain, TETRA has an edge. 

In some cases, 5G and TETRA can both be deployed, and the unified system can be connected at the trunk. In such cases, people would appreciate the option of having both technologies. Some areas can be covered by private 5G while others are serviced by TETRA.

For example, in environments like hospitals, warehouses, oil & gas refineries and airports, where communication happens  above the ground surface and data communication is important, it makes sense to use private 5G or hybrid 5G. The handsets are small and mobile users can access all their applications, thanks to 5G technology and the Network Slicing function.   In addition, a great advantage of 5G is the ability to hook to any network in case of an emergency. 5G for emergency use, along with automation, AI, Analytics and IoT, make 5G an excellent choice for developers. In the short term, both  technologies will coexist. However, in the long run  5G is expected to take over  the majority of TETRA traffic.

Swapnil P N Srivastava
DMTS- Senior Member (Communications), Wipro.

Swapnil has over 28 years of experience in Telecom. He is experienced in Telecom Equipment Design, Baseband Design and System Integrations working in various functions like Equipment Design, Product Management,  Telecom Technical Consulting and Presales. He owns patented IPs in the field of optical network.

He is currently leading 5G network practice in Wipro CIS team.

Ashish Khare
General Manager & Practice Head – IOT, 5G & Smart City, Wipro

Ashish has over 30 years of experience in Consulting, SI & Manage Services in IT & OT.  He is currently working on various 5G and IoT solutions for multiple industries. He heads the 5G, IoT and Smart City CIS group. He is working on IT-OT convergence & Service Management framework for IoT.  He owns multiple IP’s including Wipro Smart i-connect™, Platform for Smart Spaces & IoT, won innovation awards.