Progress of M2M technology standards at home and abroad in the Internet of Things

1 Introduction

The Internet of Things is called another wave of information industry after computers, the Internet and mobile communication networks, and will bring a vast new market to IT and communications.

In 2005, the International Telecommunication Union (ITU) formally proposed the concept of "Internet of Things" in the "ITU Internet Report 2005: Internet of Things" released at the World Summit on the Information Society (WSIS). The report pointed out: "The era of ubiquitous Internet of Things communications is coming, and all objects in the world, from tires to toothbrushes, from houses to paper towels, can actively exchange information through the Internet." In general, the Internet of Things is "a network of objects connected to each other." There are two meanings here: first, the providers and users of information gradually expand from people to physical entities, and objects communicate and exchange information through the Internet of Things; second, the interconnection between physical entities is achieved through various wireless and/or wired, long-distance and/or short-distance communication networks, and the communication and transmission process does not require or only requires limited human intervention.

The European Platform for Smart Systems (EPoSS) analyzed and predicted in its report "Internet of Things in 2020" that the development of the Internet of Things will go through four stages. Before 2010, RFID was widely used in logistics, retail and pharmaceutical fields. From 2010 to 2015, objects were connected. From 2015 to 2020, objects became semi-intelligent. After 2020, objects will become fully intelligent.

M2M is the abbreviation of "machine to machine" or "man to machine". It mainly refers to the data exchange between machines or people through the "communication network" to achieve information transmission, that is, to achieve the interconnection and intercommunication between machines through the communication network. Due to the special characteristics of the mobile communication network, the terminal side does not need manual wiring, can provide mobility support, is conducive to cost saving, and can meet the communication needs in dangerous environments, so that the M2M service carried by the mobile communication network has received widespread attention in the industry.

As the most common application form of the Internet of Things at this stage, M2M has achieved commercial applications in Europe, the United States, South Korea, Japan and other countries. It is mainly used in safety monitoring, mechanical service and maintenance business, public transportation system, fleet management, industrial automation, urban informatization and other fields. Mainstream operators providing M2M services include BT and Vodafone in the UK, T-Mobile in Germany, NTT-DoCoMo in Japan, SK in South Korea, etc. China's M2M application started early and is currently in a rapid development stage. Major operators are actively researching M2M technology and trying their best to expand the M2M application market.

The research and standard setting work related to M2M in major international standardization organizations is also advancing. Several major standardization organizations have carried out targeted research from different angles according to their respective work scope. ETSI started with the research on typical IoT business use cases, such as smart medical, e-commerce, automated cities, smart meter reading and smart grid, and completed the analysis of IoT business needs, the design of the outline layer architecture supporting IoT business, and the definition of related data models, interfaces and processes. 3GPP/3GPP2 takes mobile communication technology as the core of its work, focusing on the network optimization related technologies that need to be implemented in 3G, LTE/CDMA networks for the provision of IoT services, and the research involves business needs, core network and wireless network optimization, security and other fields. CCSA completed the M2M business research report as early as 2009, and other research work related to M2M has been launched.

This article mainly introduces the progress of M2M work in international and domestic standardization organizations.

2 Overview of M2M Progress in ETSI

ETSI is an international standardization organization that systematically carried out M2M-related research earlier. In early 2009, a special TC was established to coordinate M2M research, aiming to develop a horizontal, end-to-end solution standard that is not targeted at specific M2M applications. Its research scope can be divided into two levels. The first level is the collection and analysis of M2M application use cases; the second level is to carry out business demand analysis of application-independent unified M2M solutions, network architecture definition, and data model, interface and process design based on use case research. According to the TC's plan, the research work is divided into three stages, as shown in Table 1.

Table 1 ETSI TC M2M research phases

ETSI has studied more than ten M2M-related standards, including:

(1) M2M Service Requirements: This research topic describes the requirements for end-to-end system capabilities to support M2M communication services. The report was released in August 2010.

(2) M2M functional architecture, focusing on the network functional architecture that provides M2M services for M2M applications, including the definition of new functional entities, standard access points and summary-level call flows between ETSI and other TBs or other standardization organizations. The output of this research topic will be the starting point for the third phase of work and a reference point for coordination with other standard organizations' IoT-related research. Figure 1 shows the M2M architecture proposed in the report. As can be seen from the figure, M2M technology involves all levels of the communication network, from terminals to networks to applications. The bearer network of M2M includes various types of communication networks defined by 3GPP, TISPAN and IETF.

Figure 1 ETSI M2M communication functional architecture

(3) M2M terms and definitions: Define M2M terms to ensure consistency of terms across working groups. The draft is currently under discussion and the official version is expected to be released by the end of the first quarter of 2011.

(4) Smart Metering M2M Application Case Study: This topic describes the use cases of Smart Metering, including the definition of roles and information flows, which will serve as the basis for defining the business requirements of smart metering.

(5) eHealth M2M Application Case Study: This topic studies smart healthcare, a key IoT application case, to demonstrate the enhancement of communication network functions and capabilities to support M2M services. This topic is coordinated with related research in ETSI TC eHEALTH and is expected to be officially released in July 2011.

(6) Case Study of M2M Application of User Interconnection. This research report defines the use case of M2M application of user interconnection and is expected to be officially released in July 2011.

(7) Case Study of M2M Applications in Urban Automation: This topic collects use cases and related characteristics of automated cities to describe the requirements of future M2M-capable networks to support such applications and the enhancement of network functions and capabilities. The first draft is currently under discussion and the official version is expected to be released in July 2011.

(8) Based on the automotive application of M2M application case study, the project collects use cases and related characteristics of automation applications to describe the future M2M-capable network support requirements and network function and capability enhancements. The first draft is currently under discussion and the official version is expected to be released in July 2011.

(9) ETSI's work plan and output summary for M/441. This research is part of the EU Smart Meter project (EU Mandate M/441). This topic will submit a research report to EU Mandate M/441, which includes the planning to support Smart Meter applications and other technical committee outputs. The first draft is currently under discussion and the official version is expected to be released in July 2011.

(10) Impact of Smart Grid on M2M Platform: This topic is based on the M2M overview architecture framework defined by ETSI. It studies the applicability of M2M platform to smart grid and analyzes the differences between existing standards and actual applications. It is currently in the pre-launch preparation stage and is expected to release the official version in May 2011.

(11) M2M interface: Based on the research of network architecture, this topic mainly completes the work of protocol/API, data model and coding. At present, the above contents are combined in one standard. In the future, when the standard enters the stable stage, it may be split into multiple standard documents according to different interfaces. It is currently in the drafting stage and the official version is expected to be released in February 2011.

3 Overview of M2M Standardization in 3GPP

As early as September 2005, 3GPP conducted a feasibility study on mobile communication systems supporting IoT applications, and formal research was launched in the R10 phase. The corresponding name of M2M in 3GPP is Machine-Type Communication (MTC). 3GPP has established multiple work items or study items in parallel, and different working groups have carried out research on MTC in parallel according to their fields. The following briefly describes the progress of 3GPP's related research work in the MTC field according to the classification of the projects.

(1) FS_M2M: This project is a feasibility study report on M2M communication conducted by 3GPP, and SA1 is responsible for the relevant research work. The research report "Feasibility Study on Supporting M2M Communication in 3GPP System" was launched in September 2005 and completed in March 2007.

(2) NIMTC-related topics focus on the enhancement requirements of mobile communication networks to support machine-type communications, including the enhancement requirements for GSM, UTRAN, EUTRAN, and the enhancement requirements for core networks such as GPRS and EPC. The main projects include:

●FS_NIMTC_GERAN: This project was launched in May 2010 and focuses on the enhancement of the GERAN system for machine-type communications.

●FS_NIMTC_RAN: This project was launched in August 2009 and focuses on the enhancement requirements for 3G wireless networks and LTE wireless networks to support machine type communications.

●NIMTC: This research project is a key research topic of machine type communication, responsible for studying network enhancement technologies that support communication between machine type terminals and IoT application servers located in operator networks, private networks or the Internet. SA1, SA2, SA3 and CT1, CT3, CT4 working groups are responsible for their respective parts of the work.

——3GPP SA1 working group is responsible for the research on machine type communication service requirements. In early 2009, the technical specification was launched, and the functional requirements of MTC for communication networks were divided into two categories: common and characteristic, which can be optimized.

——SA2 working group is responsible for the research of mobile core network architecture and optimization technology supporting machine type communication. The research report "System Enhancement to Support Machine Type Communication" was officially launched at the end of 2009. The report provides solutions for the common and characteristic technical points given in the first phase requirements.

——SA3 working group is responsible for security-related research. In 2007, it launched the report "Feasibility Study on Remote Control and Modification of M2M Terminal Contract Information", which studies the remote contract management of M2M devices when M2M applications are stored in UICC, including the trust model of remote contract, security requirements and corresponding solutions. The research report "Security Features of M2M Communication" launched in 2009 plans to study the security features and requirements of mobile networks to support MTC communications based on the work of SA2.

(3) FS_MTCe: Enhanced research on supporting machine type communications is a new research project planned to be launched in the Release 11 phase. It is mainly responsible for studying network optimization technologies that support communications between MTC devices located in different PLMN domains. The research of this project needs to be coordinated with related research in ETSI TC M2M.

(4) FS_AMTC: This research project aims to find a replacement for E.164 for identifying machine type terminals and routing messages between terminals. It is a new research topic in the R11 phase and was launched in February 2010.

(5) SIMTC: Research on system enhancement to support machine type communications. This is a new research topic in the R11 phase. Based on the FS_MTCe project, this study will focus on an enhanced version of the R10 phase NIMTC solution.

The core work of the 3GPP network enhancement research project to support machine type communications in the R10 stage is the ongoing research on MTC architecture enhancement by the SA2 working group. The network optimization technologies that support MTC communications include:

●System architecture

The research report proposes modifications to the NIMTC architecture, including adding an MTC IWF functional entity to enable data and control signaling interaction between the operator network and the IoT server located on a private or public network, and requires that the modified architecture provide support for MTC terminal roaming scenarios.

Congestion and overload control

Since the number of MTC terminals may reach several orders of magnitude more than the number of existing mobile phone terminals, network congestion and overload caused by a large number of MTC terminals simultaneously attaching or initiating service requests are the most urgent problems faced by mobile network operators. The research report focused on this aspect and discussed various congestion and overload scenarios that require the network to accurately locate the location of congestion and the IoT applications that cause congestion. For different congestion scenarios and types, a variety of solutions are provided, such as access layer blocking broadcasts, low access priority indication, and resetting periodic location update time.

●Contract control

The research report analyzes the issues related to MTC contract control and proposes that SGSN/MME has the ability to decide whether to enable or disable certain MTC features based on MTC device capabilities, network capabilities, operator policies and MTC contract information. It also points out issues that need further research, such as how the network obtains MTC device capabilities and the roaming scenarios of MTC devices.

●Identification and addressing

The identification problem of MTC communication has been separately studied in detail. This report mainly studies the addressing method of MTC terminals in the MT process. According to the different deployment locations of MTC servers, the report analyzes the requirements of addressing functions in detail and provides two solutions: NATTT and micro-port forwarding technology addressing.

●Time control characteristics

The time-controlled feature is suitable for IoT applications that can complete data transmission and reception within a preset time period. The report points out that the home network operator should preset the permitted time period and service prohibited time period of MTC terminals respectively. The service network operator can modify the permitted time period according to local policies and set the communication window of MTC terminals.

●MTC monitoring features

MTC monitoring is a monitoring service for MTC terminal behavior provided by the operator network to IoT subscribers, including complete solutions such as monitoring event signing, monitoring event detection, event reporting and subsequent action triggering.

4 Overview of M2M Standardization Progress in 3GPP2

To promote the research of M2M supporting technology of CDAM system, 3GPP2 approved the establishment of M2M project at the Bangkok meeting in January 2010. It is suggested to accelerate the research process of M2M from the following aspects.

(1) When operators deploy M2M applications, they should bring lower operational complexity to the operators.

(2) Reduce the impact and processing workload of handling large numbers of M2M device groups on the network.

(3) Optimizing network operation modes to reduce the impact on M2M terminal power consumption and other research areas.

(4) Operators can provide services that meet M2M needs and encourage the deployment of more M2M applications.

The research on M2M in 3GPP2 refers to the business requirements defined in 3GPP, and focuses on how cdma2000 networks support M2M communications. Specific contents include 3GPP2 architecture enhancements, wireless network enhancements, and packet data core network enhancements.

5 Overview of M2M Progress in CCSA

M2M-related standardization work is mainly carried out in the Mobile Communications Working Committee (TC5) and the Ubiquitous Network Technology Working Committee (TC10) of the China Communications Standards Association. The main work contents are as follows:

(1) TC5 WG7 completed a research report on mobile M2M services, describing typical applications of M2M, analyzing the business model, service characteristics and traffic model of M2M, and providing recommendations for the standardization of M2M services.

(2) TC5 WG9 initiated the research on mobile network technology supporting M2M communication in 2010. Its mission is to track the research progress of 3GPP and study the impact of M2M communication on RAN and core network and its optimization solutions in light of domestic needs.

(3) TC10 WG2 Overall technical requirements for M2M services, defining the concept of M2M services, describing M2M scenarios and service requirements, system architecture, interfaces, and billing authentication requirements.

(4) TC10 WG2 M2M communication application protocol technical requirements, specifies the end-to-end protocol technical requirements in M2M communication systems.

6 Conclusion

M2M research is one of the research focuses of ETSI, 3GPP and 3GPP2 standardization organizations. The research is relatively more systematic and the progress is relatively fast. On the basis of completing the work in the demand phase, the second phase network system architecture has also achieved preliminary results. 3GPP's research focus is on mobile network optimization technology, and it has already achieved phased research results; ETSI has studied the application requirements of various industries, and the process of transplanting the results to applications is relatively smooth. At the same time, the two standardization organizations pay attention to maintaining the coordination and compatibility between the two research systems, and domestic standardization work is in full swing. Standardization is an important part of the development of the Internet of Things. The research and formulation of M2M standardization work is of great significance to the development of the Internet of Things, the development of my country's Internet of Things technology, and even the integration of the communications industry and the Internet of Things application industry. It has important reference value and guiding significance.