An M2M-Based Interface Management Framework for Vehicles with Multiple Network Interfaces

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1 An M2M-Based Interface Management Framework for Vehicles with Multiple Network Interfaces Hong-Jong Jeong, Sungwon Lee, Dongkyun Kim and Yong-Geun Hong Abstract The Intelligent Transportation System (ITS) can be considered the most representative example of Machine-to-Machine (M2M) applications in a standardization and commercial market. To support the applications, utilizing multiple network interfaces and providing appropriate network connectivity to them are the key issues in order to meet different network requirements of M2M applications on ITS devices. Moreover, different from applications which are controlled by a human operator, the ITS device with M2M application is required to decide the appropriate air interface and network for each application by itself according to the predefined policy and network status. In this paper, we therefore propose a novel multiple network interface management framework for ITS devices with M2M applications having their different requirements and constraints based on the CALM architecture. This can provide the M2M applications with extensible and flexible system environments based on the CALM architecture. H.-J. Jeong Department of Computer Engineering, Kyungpook National University, 80, Daehak-ro, Buk-gu, Daegu, South Korea hjjeong@monet.knu.ac.kr S. Lee School of Electrical Engineering and Computer Science, Kyungpook National University, 80, Daehak-ro, Buk-gu, Daegu, South Korea swlee@monet.knu.ac.kr D. Kim (&) School of Computer Science and Engineering, Kyungpook National University, 80, Daehak-ro, Buk-gu, Daegu, South Korea dongkyun@knu.ac.kr Y.-G. Hong Electronics and Telecommunications Research Institute, 218 Gajeong-ro, Yuseong-gu, Daejeon, South Korea yghong@etri.re.kr K. J. Kim and K.-Y. Chung (eds.), IT Convergence and Security 2012, Lecture Notes in Electrical Engineering 215, DOI: / _50, Ó Springer Science+Business Media Dordrecht

2 410 H.-J. Jeong et al. Keywords M2M Machine-to-machine ITS Communication Multiple interfaces CALM 1 Introduction Machine-to-Machine (M2M) communication is characterized by low power, low cost, and low human intervention, supporting a wide range of applications in different domains such as u-healthcare, intelligent transportation system, smart energy, and etc. [1]. Among them, Intelligent Transportation System (ITS) can be the most representative example of M2M applications in a standardization and commercial market. ITS can be used to prevent vehicular accidents, increase the efficiency of transportation system and reduce environmental pollution, while improving passengers convenience [2]. ETSI, European Telecommunications Standards Institute, considers several use cases of automotive applications in M2M capable networks such as electricity vehicle charging, fleet management, theft tracking, and information exchanges [3]. They have different sizes of data transmitted by each application (from several bytes to hundreds of megabytes). Moreover, the urgency of data is also subjective to the requirements of the applications. In particular, the architecture of Communication Access for Land Mobile (CALM) is defined by ISO TC204 WG16 standard body, where ITS devices such as Road Side Unit (RSU) and On-Board Unit (OBU) can be equipped with multiple network interfaces using various access technologies to provide network connectivity [4]. CALM-compliant systems provide the ability to use the heterogeneous access technologies for data delivery with different characteristics with each other in terms of network coverage, cost, bandwidth, jitter, and etc. [5]. Therefore, an ITS device should be able to manage and use multiple network interfaces efficiently. Since each ITS M2M application has different network requirements and constraints, managing of multiple interfaces and providing appropriate network connectivity to the application based on its requirement are the key issues to providing ITS M2M applications. Moreover, as the network condition constantly changes due to continuous movements of vehicles, an ITS device with M2M applications (hereafter, called an ITS M2M device) should keep monitoring the network condition and use the best suitable network for an M2M application according to the network selection policy without any human operation. Therefore, the ITS M2M device should be able to periodically update the network information and the policies required for selecting a suitable network regardless of manufacturers and network providers. In this paper, we propose a new multiple interface management framework for ITS M2M device based on the CALM architecture. To the best of our knowledge, this is the first trial involving multiple interface management for ITS M2M devices.

3 An M2M-Based Interface Management Framework Related Work The CALM architecture is an initiative to define a set of communication protocols and interfaces which are used for ITS communications [4]. Particularly, unlike the other ITS architectures such as WAVE standard [6 9], the CALM architecture can support multiple air interfaces for a variety of communication scenarios. Hence, in each of communication scenarios which have different requirements and constraints, the CALM architecture can provide the applications with appropriate communication service through interface selection. In the CALM architecture, all communications between communication entities, called ITS stations (ITS-S) which include vehicles, personal devices, RSUs, and central stations are performed in a peer-to-peer manner. In order to support the peer-to-peer communications among them, network protocol stacks on ITS-S and their relationships should follow the ITS-S reference architecture which is defined in the CALM architecture standard. Fig. 1 Reference architecture of ITS station

4 412 H.-J. Jeong et al. Figure 1 shows the reference architecture of ITS-S. As shown in Fig. 1, the first layer of the ITS-S architecture, called Access layer, represents the physical and link layer. Link control protocols and various physical interfaces such as Bluetooth, 3G/4G and WLAN are comprised in this layer. The second layer of the architecture, called Networking & Transport layer, corresponds to the network and transport layer in the OSI layer architecture. This layer is responsible for ITS Transport, TCP/UDP, IPv6 mobility extension, and other network protocols. The third layer of the architecture, called Facilities layer, provides upper layers with application/information/session support. Additionally, in order to provide security and interact with the layers of the ITS-S reference architecture, the security entity and management entity are resided outside the ITS-S protocol stack and connected with each layer of the ITS-S reference architecture, respectively. Finally, the application layer is operated over all these layers. 3 Proposed MI ITS M2M Model In this section, we introduce our proposed Multiple Interface (MI) management framework for ITS M2M devices based on the CALM architecture. As shown in Fig. 2, it consists of three parties: (a) An ITS M2M device (OBU) which is equipped with multiple interfaces and contains several M2M applications (b) An ITS access network (RSU) which provides network connectivity to the ITS M2M device and its parameters of the access network, and (c) An ITS M2M server which provides the MI management policy to the ITS M2M device and may make a decision to select an appropriate network for ITS M2M device. Fig. 2 Conceptual model of our MI ITS M2M system

5 An M2M-Based Interface Management Framework 413 Different from a human operating system, which is controlled by a human operator considering overall information of networks and requirements of applications, the ITS M2M device is required to decide the appropriate network for the each application by itself according to the predefined policy and network status. For example, an ITS M2M application to report vehicular accidents should transmit its message to the ITS M2M server despite the high cost of network usage. On the other hand, the transmission of non-time critical data of huge size can be postponed until the ITS M2M device succeeds in establishing a network connection with low cost or free of charge. 4 M2M MI Management Framework Figure 3 shows our proposed the structure of the MI ITS M2M framework based on the CALM architecture. In MI ITS M2M systems, several ITS M2M applications which have different communication requirements are assumed to run on an ITS M2M device. In order to manage multiple interfaces efficiently for several M2M applications on an ITS device, we define four agents into Management Information Base (MIB) of the CALM architecture as follows. As shown in Fig. 3, the agents are interconnected via several Service Access Points (SAPs) such as MA-SAP, MF-SAP, MN-SAP and MI-SAP. According to the reference model of CALM Architecture, we define SAP primitives which are responsible for sending and receiving commands as well as reading and setting parameters. Fig. 3 MI ITS M2M architecture

6 414 H.-J. Jeong et al. MI Description Agent: Exchanges the network interface information Profile (data rate, cost, bandwidth, error rate, jitter, and etc.) and the network selection policy (Preference of networks, cost metrics, and etc.) with ITS M2M server and RSU. MI Information Delivery Agent: Delivers the network interface information profile and network selection policy through a transportation scheme such as http and CoAP. MI Selection Agent: Selects an interface for an M2M application according to the policy from the M2M server. MI Management Agent: Monitors the network status and manages the network profile of each network. Triggers re-configuration for the interface selection when the previous selected interface violates the policy. Figure 4 gives an information flows between the interface selection agent and the horizontal layers. Multiple Interface Selection agent maintains three information: MI selection policy, Interface information table and Network information table. MI selection policy contains the policy information required for network and interface selection such as preference of networks and cost metrics which is delivered from ITS M2M server and RSU. Interface information table and Network information table maintain the parameters of air interfaces and networks such as data rate, cost, bandwidth, error/loss rate and jitter. These information is obtained from MA-SAP, MF-SAP, MN-SAP and MI-SAP through Mx-REQUEST command. The decision of interface selection is sent to the Network & Transport layer via MN-SPA using MN-Command. 4.1 Data Exchanges and Usage In order to provide interoperability for exchanging the network interface information profile and network selection policy among M2M devices and servers from different manufactures, the system should use a description language in a form of XML schema, and can describe policies and functions of selecting a network interface. Figure 5 shows an example of the network interface information profile. In order to select a network interface for a specific M2M application by itself, each of ITS M2M devices is required to exchange data as follows. ITS M2M Server Ô ITS M2M device: policies for interface selection, authentication and billing information of each network, and etc. ITS M2M device Ô ITS M2M Server: status of network connectivity, available networks, and etc.

7 An M2M-Based Interface Management Framework 415 Fig. 4 Information flow between interface selection agent and the horizontal layers Fig. 5 Example of the network interface information profile ITS M2M RSU Ô ITS M2M device: network channel, bandwidth, jitter, QoS, and etc. ITS M2M device Ô ITS M2M RSU: authentication for the connection establishment, and etc. 5 Conclusion In this paper, we proposed a multiple network interface management framework for ITS M2M devices in order to meet different network requirements and constraints for each of their ITS M2M applications. Our proposed framework consisting of four agents keeps monitoring the status of network interfaces and selects the best suitable interface for each M2M application according to the network selection policy without any human operation.

8 416 H.-J. Jeong et al. The framework is designed based on the CALM architecture and uses a description language in a form of XML schema for exchanging the network interface information and network selection policies. Through this framework, the interoperability and flexibility for ITS M2M systems can be provided, regardless of manufacturers and network providers. Acknowledgments This research was supported by the MKE (The Ministry of Knowledge Economy), Korea, under the CITRC (Convergence Information Technology Research Center) support program (NIPA-2012-H ) supervised by the NIPA (National IT Industry Promotion Agency). This research was also supported by the ICT Standardization program of KCC (Korea Communications Commission). This research was also supported by Kyungpook National University Research Fund, References 1. Wu G, Talwar S, Johnsson K, Himayat N, Johnson KD (2011) M2M: from mobile to embedded internet. IEEE Commun Mag 49(4): Chen B, Cheng HH (2010) A review of the applications of agent technology in traffic and transportation systems. IEEE Trans Intell Transp Syst 11(2): ETSI (2010) Machine to machine communications (M2M): use cases of automotive applications in M2M capable networks, ETSI TR V0.4.0, Sept ISO/TC TC204/SC WG16 (2012) Intelligent transport systems communications access for land mobiles (CALM) architecture, ISO/WD 21217, March Williams B (2006) CALM handbook v3, CALM forum, March IEEE P SWG et al (2009) IEEE P trial-use standard for wireless access in vehicular environments (WAVE) resource manager, IEEE P D0.6, June IEEE P SWG et al (2009) IEEE P trial-use standard for wireless access in vehicular environments security services for applications and management messages, IEEE P D07, June IEEE P SWG et al (2009) IEEE P wireless access in vehicular environments (WAVE) networking services, IEEE P D1.2, June IEEE P SWG et al (2009) IEEE P trial-use standard for wireless access in vehicular environments (WAVE) multi-channel operation, IEEE P D12, June 2009