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5.4 Processes – Machine to Machine communications (MTC)

Unlike HTC communications, this type of communication, also called M2M (Machine to Machine),
covers the communication of data between entities that do not necessarily require human
intervention. HTC traffic, mainly generated by IoT devices, presents very different patterns from
traditional traffic patterns and is experiencing significant growth, and as a result, will probably
become the dominant traffic on the network.

This section also includes traffic derived from the interconnection between information systems,
access to databases, file transfer, among others.

Telecommunication networks, especially cellular networks, were designed for a limited number of
users with homogeneous characteristics; consequently, the support of a large number of devices
with heterogeneous requirements represents an important challenge in multiple aspects of the
network architecture itself such as signalling, the nature of traffic, classes of service or the number
of devices per cell.

As general characteristics of MTC traffic, we can highlight:

• A large number of devices.
• Traffic patterns with a low duty cycle, i.e., a long period between two transmissions.

• The number of packets transmitted per device is “low”, and their size is “small”.

• The traffic pattern of the devices shows small variations.
• The traffic generated by the devices is usually asymmetric, with the uplink higher than the
downlink.

• There are different types of service (best effort and real time).

• A device can contain traffic from multiple sources (aggregated packets).
• Device traffic can be coordinated by application requirements.

Together with these characteristics related to the nature of the traffic, its behaviour has been
classified for purposes of modelling the traffic and guaranteeing an adequate level of quality.

• Reduced mobility: Applies to MTC devices that do not move, move very little, or do so in a
certain locality.

• Real-time (controlled): Useful for applications that allow information to be sent/received for
defined periods of time. The network does not consume unnecessary signaling resources
outside of these intervals.

56 Reference framework for integrated management of an SSC | June 2023