The Internet of things (IoT) has challenges that are different from the traditional Internet in a different massive influx of data and unpredictable network conditions. On the other hand, software-defined networking (SDN) is a promising approach to control the network in a unified using rule-based management, The abstractions provided by SDN enable holistic control or network using high-level policies, without being concerned about the low-level configuration is Hemoe, it is advantageous to address the heterogeneity and application-specifics IoT. Software-defined wide-area networking (SD-WAN), has emerged in recent years with the aim to simplify all of this complexity and help evolve enterprise networks into more flexible programmable architectures that can meet the changing expectations of users, requirements of 

The term "machine-to-machine" communication technology is used to describe any form of connection between two devices that don't require human assistance. M2M cornerstone of the IoT. The Internet of Things is a system of devices with unique identifiers (known as UID) capable of transmitting information over a network, IoT requires no human-to-human or human-to-machine interaction. Now IoT is widely used in industries like the automotive (autonomous car, vehicle-to-vehicle communication), logistics and supply (supply chain tracking), manufacturing (warehouse management), banking (connected branches), and so on. While M2M enables device-to-device communication, the Internet of Things allows multiple machines to design a connected data network.

What is Machine-to-Machine Communication (M2M) 

Machine to Machine or M2M is like two machines communicating or exchanging data without human interaction. M2M includes serial connection, powerline connection (PLC), and wireless connection. Or we can say that M2M communication is like cellular communication for embedded devices. IoT and M2M are almost synonymous. The exception is that IoT prefers wireless. communication and M2M prefer to any 2 machines - wireless or wired communication with one another According to Forbes, M2M is a widely increasing type.of.connected device technology in the market because M2M.technology can connect- millions of devices within a single network. M2M network is very similar to LAN or WAN but is exclusively used to allow machines and sensors. and control to communicate. Artificial Intelligence and Machine Learning provide the communication between systems, allowing them to make their own autonomous choices. M2M technology was first introduced in Industrial and Manufacturing where other technologies such as SCADA (a principle of the remote monitoring system. that transmits data from a device into a program and presents it in the form of insights) and remote monitoring helped remoting control and manage data from equipment. M2M is found in other areas like healthcare, business, and insurance. M2M is also the foundation for IoT. The first use-of M2M communication is credited to Theodore Paraskevakos, who invented this technology related to the transmission of data over telephone lines, the basis for modern-day caller-ID. 

M2M communication is a point to point communication that allows the network to transmit information via public networking technologies such as Ethernet and cellular networks. Sensor telemetry is one of the applications of M2M. Businesses are using M2M to remotely monitor factors such as temperature, energy consumption, moisture, pressure, etc. The second example of M2M is.ATM. ATM's internal computer is continually communicating with a host computer that routes appropriate banks and accounts. The bank sends back approval codes through the host computer; allowing transactions to be completed. The entire transaction happens remotely and without any human interaction on the bank's side. Machine communication efficiently, automatically allowing transactions to be authorized in seconds. 

The main purpose of machine-to-machine technology is to tap into sensor data and transmit it to a network. Unlike SCADA or other remote monitoring tools, M2M systems often use public networks and access methods -- for example, cellular or Ethernet - to make it more cost-effective. The main components of an M2M system include sensors and RFID. a Wi-Fi or cellular communications link, and autonomic computing software programmed to help a network device interpret data and make decisions. These M2M applications translate the data, which can trigger preprogrammed, automated actions. 

The benefits of M2M 

  • Reduced costs by minimizing equipment maintenance and downtime. 
  • Boosted revenue by revealing new business opportunities for servicing products in the field. 
  • Improved customer service by proactively monitoring and servicing equipment before it fails or only when it is needed. 

machine to machine communication (M2M)
Fig. Machine-to-Machine Communication (M2M)

Features of M2M 

  • Low power consumption, in an effort to improve the system's ability to service M2M applications. effectively 
  • A network operator that provides packet-switched service 
  • Monitoring abilities that provide the functionality to detect events. 
  • Time tolerance, meaning data transfers can be delayed. 
  • Time control, meaning data can only be sent or received at specific predetermined periods. 
  • Location-specific triggers that alert or wake up devices when they enter a particular area. 
  • The ability to continually send and receive small amounts of data. 

Requirements of M2M 

According to the European Telecommunications Standards Institute (ETSI), requirements of an M2M system include:
  • Scalability - The M2M system should be able to continue to function efficiently more connected objects are added. 
  • Anonymity - The M2M system must be able to hide the identity of M2M devices when requested, subject to regulatory requirements.
  • Logging - M2M systems must support the recording of important events, such as failed installation attempts, service not operating, or the occurrence of faulty information. The logs should be available by request.
  • M2M Application Communication Principles - M2M systems should enable communication between M2M applications in the network and the M2M device or gateway using communication techniques, such as short message service (SMS) and IP Connected devices should also be able to communicate with each other in a peer-to-peer (P2P) manner.
  • Delivery Methods - The M2M system should support unicast, anycast, multicast, and broadcast communication modes, with the broadcast being replaced by multicast or anycast whenever possible to minimize the load on the communication network.
  • Message Transmission Scheduling - M2M systems must be able to control network access and messaging schedules and should be conscious of M2M application scheduling delay tolerance.
  • Message Communication Path Selection - Optimization of the message communication paths within an M2M system must be possible and based on policies like transmission failures, delays when other paths exist, and network costs. 

M2M Security 

Machine-to-machine systems face a number of security issues, from unauthorized access to wireless intrusion to device hacking. Physical security, privacy, fraud, and the exposure of mission-critical applications must also be considered. Typical M2M security measures include making devices and machines tamper-resistant, embedding security into the machines, ensuring communication security through encryption, and securing back-end servers, among others. Segmenting M2M devices onto their own network and managing device identity, data confidentiality and device availability can also help combat M2M security risks. 

M2M Standards

Machine-to-machine technology does not have a standardized device platform, and many M2M systems are built to be task- or device-specific. Several key M2M standards, many of which are also used in IoT settings, have emerged over the years, including:
  • OMA LightweightM2M, a device management protocol 
  • MQTT, a messaging protocol 
  • TR-069 (Technical Report 069), an application layer protocol 
  • HyperCat, a data discovery protocol 
  • OneM2M, a communications protocol 
  • Google Thread, a wireless mesh protocol 
  • AllJoyn, an open-source software framework